WO2017068071A1

WO2017068071A1 - Apparatus for manufacturing liquid enzyme, and a system & method for coating pellets with the liquid enzyme

Info

Publication number: WO2017068071A1
Application number: PCT/EP2016/075281
Authority: WO
Inventors: Lode NOLLET; Karel BIERMAN; Spas PETKOV
Original assignee: Huvepharma Eood
Priority date: 2015-10-20
Filing date: 2016-10-20
Publication date: 2017-04-27
Also published as: GB2543530A; NL2017649B1; GB201518585D0; NL2017649A

Abstract

Apparatus (3) for manufacturing a liquid. The apparatus (3) is arranged for inclusion in a pellet coating system (1) to supply the liquid to downstream apparatus such as a pellet coating station (204). The apparatus (3) includes: a mixing vessel (9); a mixing device (13) for mixing substances located in the mixing vessel (9); water supply means (21) arranged to supply water to the mixing vessel (9); a first storage vessel (7) for storing a first particulate material; a weighing system (17); a feed system (11) for feeding first particulate material to the mixing vessel (9); and a control system (19); wherein the control system (19) is arranged to receive signals from the weighing system (17) and to control operation of at least part of the feed system (11) according to the signals received from the weighing system (17) to deliver a target mass of first particulate material to the mixing vessel (9). A system (1) for coating pellets, such as feed pellets. The system includes: the apparatus (3) for manufacturing at least one liquid; a pellet source (202); at least one pellet coating device (204); means for feeding at least one liquid from the manufacturing apparatus (3) to the pellet coating device (208; 83); wherein the pellet coating device (204) is arranged to apply the or each liquid to at least some of the pellets received from the pellet source (202).

Description

APPARATUS FOR MANUFACTURING LIQUID ENZYME, AND A SYSTEM &

METHOD FOR COATING PELLETS WITH THE LIQUID ENZYME

The present invention relates to apparatus for manufacturing a liquid, such as a liquid including at least one enzyme; a method for manufacturing a liquid including at least one enzyme; a system for coating pellets, for example a Post Pellet Liquid Application (PPLA) system; and a method for coating pellets, for example a PPLA method.

Figure 1 shows an example of a PPLA system, which includes a pellet silo 202; a pellet coating device 204 arranged to apply one or more liquids to pellets; a feeder 206 arranged to feed pellets from the silo 202 to the coating device 204; an enzyme dosing system 208; a phytase dosing system 210; and fat dosing system 212.

In the PPLA system shown in Figure 1 the liquid enzyme is manufactured off site by a supplier and is transported to the PPLA site typically by road or rail in Intermediate Bulk Containers (IBC). The IBCs are stored, for example in a warehouse, until required. Refrigerated transport and storage is often necessary. When required for a pellet coating process, an IBC 214a is connected to a supply line 216. The liquid enzyme is pumped from the IBC via a pump 218 to an intermediate storage tank 219. The liquid enzyme is supplied to the pellet coating device 204 by another pump 222 during a pellet coating process.

When the IBC 214a is empty, it is replaced with a new IBC 214b and the original IBC 214a is disposed of. A problem with this system is that liquid enzyme is heavy and it is expensive to transport and store IBCs. To replace an empty IBC with a full IBC requires lifting equipment as an IBC typically weights around 1200kg. The IBCs are typically located several metres above the pellet coating device, which provides additional handling difficulties. Furthermore, during the replacement process, there is a period of time in which the no IBC is connected to the supply line 215, which can affect continuity of supply. This can be particularly problematic if a new IBC is required during a pelleting process. Also, the pellet manufacturer has to dispose of used IBCs. An additional problem is that for some liquid enzymes, enzyme activity can deteriorate significantly with time. Thus making a batch of enzyme liquid off site and transporting it to the place of use can reduce the effectiveness of the liquid enzyme.

Accordingly the present invention seeks to provide apparatus, a system and method that mitigates at least one of the aforementioned problems, or at least provides an alternative to existing apparatus, systems and methods.

According to one aspect of the invention there is provided apparatus for manufacturing a liquid, wherein the apparatus is arranged for inclusion in a pellet coating system to supply the liquid to downstream apparatus such as a pellet coating station, and includes: a mixing vessel; a mixing device for mixing substances located in the mixing vessel; water supply means arranged to supply water to the mixing vessel; a first storage vessel for storing a first particulate material; a weighing system; a feed system for feeding first particulate material to the mixing vessel; and a control system. The control system is arranged to receive signals from the weighing system and to control operation of at least part of the feed system according to the signals received from the weighing system to deliver a target mass of first particulate material to the mixing vessel.

The liquid enzymes are prepared on site where the pellet coating equipment is located. Thus the liquid enzyme is always fresh as it is typically used within 12-24 hours after preparation. It gives the nutritionist more accuracy and flexibility while dosing the enzyme in the feed.

To prepare the liquid enzyme on site, it is only necessary to stock the enzyme powder since the water is provided from a water main. One 10 kg bag of instant enzyme powder replaces a 1,000 litre IBC, therefore there are significant transport and storage savings.

Including the liquid manufacturing apparatus within a pellet coating systems leads to a strong cost reduction; lower packaging costs; lower warehousing costs; lower shipping costs; better enzyme shelf-life; and higher sustainability. There are logistics benefits; less material handling in production; less storage space required; there are no IBCs to dispose of; it is more convenient than using IBCs; and the enzyme is freshly made on site shortly before it is required for use. Advantageous optional features of preferred embodiments are disclosed in the dependent claims and in the statements of invention below.

The feed system is arranged to feed first particulate material to the weighing system, and to feed first particulate material from the weighing system to the mixing vessel. The feed system transports first particulate material along a feed path from the first storage vessel to the mixing vessel. The weighing system is located on the feed path between the first storage vessel and the mixing vessel. The weighing system is arranged to weigh first particulate material. The weighing system determines a mass of first particulate material dispensed from the first storage vessel. This enables the control system to accurately control the mass of the first particulate material delivered to the mixing vessel.

The feed system includes a first feeder arranged to feed material from the first storage vessel to the weighing system and the control system is arranged to control operation of the first feeder according to signals received from weighing system. Thus the control system controls the quantity of first particulate material dispensed from the first storage vessel to the weighing system to achieve the first target mass.

The control system is arranged to cease feeding first particulate material to the weighing system, in response to the control system determining from the signals received from the weighing system that the target mass of first particulate material has been fed to the weighing system. For example, the control system is arranged to cease operation of the first feeder.

The feed system includes a second feeder arranged to feed first particulate material from the weighing system to the mixing vessel.

The control system is arranged to control operation of the second feeder according to signals received from weighing system. The control system is arranged to actuate the second feeder in response to the control system determining from the signals received from the weighing system that the target mass of first particulate material has been fed to the weighing system.

At least part of the second feeder is mounted on the weighing system. The weighing system is arranged to weigh particulate material carried by the second feeder. In some embodiments the apparatus includes a second storage vessel for storing a second particulate material.

The weighing system is arranged to weigh second particulate material. The feed system is arranged for feeding second particulate material to the weighing system. The feed system can be arranged to feed the second particulate material from the weighing system to the mixing vessel. The feed system can be arranged to feed second particulate material from the weighing system to at least one additional mixing vessel, such as a second mixing vessel.

The second particulate material can be fed to one of the mixing vessels independently of the first particulate material. For example, a first batch of liquid enzyme can be created using the first particulate material only. A second batch of liquid enzyme can be created using the second particulate material only. For other batches, both the first and second particulate materials can be fed to the mixing vessel to create a batch of liquid enzyme which includes first and second enzymes. The feed system includes a first feeder arranged to feed second particulate material from the second storage vessel to the weighing system.

The control system is arranged to control operation of the first feeder according to signals received from weighing system. Thus the control system controls the quantity of second particulate material dispensed from the second storage vessel to the weighing system. The control system is arranged to cease feeding second particulate material to the weighing system, in response to the control system determining from the signals received from the weighing system that the target mass of second particulate material has been fed to the weighing system. For example, the control system is arranged to cease operation of the first feeder. The feed system includes a second feeder arranged to feed second particulate material from the weighing system to at least one of the mixing vessels.

At least part of the second feeder is mounted on the weighing system. The weighing system is arranged to weigh particulate material carried by the second feeder. The control system is arranged to control operation of the second feeder according to signals received from weighing system.

The control system is arranged to actuate the second feeder in response to the control system determining from the signals received from the weighing system that the target mass of second particulate material has been fed to the weighing system.

The control system is arranged to adjust the rate at which the or each first feeder dispenses particulate material to the weighing system. This helps to ensure that the target mass is accurately achieved.

In some embodiments a single weighing device is used to weigh the first and second particulate materials. In some embodiments the weighing system includes a plurality of weighing devices, for example a first weighing device can be used to weigh the first particulate material and a second weighing device can be used to weigh the second particulate material.

The control system includes a user input device and memory, which enables a user to specify at least one of: the quantity, typically by mass, of the first particulate material to be delivered to the or each mixing vessel; the quantity, typically by mass, of the second particulate material to be delivered to the or each mixing vessel; the quantity of water, typically by volume or mass, supplied to the or each mixing vessel; and the mixing time for the or each mixing device. This enables the user to specify the concentration for the liquid enzyme. The set values are stored in the memory, and these are used as target values by the control system. The control system compares the signals received from the weighing system with the respective target values stored in memory to determine when to cease dispensing particulate material. The control system compares the signals received from the flow measurement device to determine when to cease supplying water to the or each mixing vessel. In preferred embodiments, the user interface is arranged to enable a user to store at least one formula for producing a liquid in the memory. The user interface enables the user to input values for at least some of the following when defining a formula: the choice of particulate material; the quantity of water; the quantity of particulate material; the ratio of particulate material: water; the tolerance for the quantity of particulate material; and the mixing time. In preferred embodiments, the apparatus is arranged to produce batches of liquid enzyme.

The control system includes a display device, and is arranged to display at least one of the following: the set quantity of the first particulate material to be delivered to the or each mixing vessel; the quantity of first particulate material already delivered; the current value of first particulate material from the weighing system; the set quantity of the second particulate material to be delivered to the or each mixing vessel; the quantity of second particulate material already delivered; the current value of second particulate material from the weighing system; the set quantity of water supplied to the or each mixing vessel; the quantity of water currently delivered to the or each mixing vessel; the set mixing time for the or each mixing device; and the mixing time elapsed since commencing the mixing process.

The water supply means includes at least one flowmeter, and the control system is arranged to control the quantity of water supplied to the or each mixing vessel according to signals received from the at least one flowmeter. Typically the control system is arranged to control the volume or mass of water supplied to the or each mixing vessel. The control system closes the valve in response to determining that a target volume or mass of water is supplied to the or each mixing vessel.

The water supply means includes at least one valve and the control system is arranged to control operation of at least one valve according to signals received from the flowmeter. The or each mixing vessel includes a first sensor, and the control system is arranged to actuate the mixing device when the first sensor detects the presence of water in the or each mixing vessel. The first sensor is located in a lower part of the respective mixing vessel.

The or each mixing vessel includes a second sensor, which is arranged as an overfill safety sensor, and the control system is arranged to cease supplying water to the or each mixing vessel in response to the second sensor detecting water. The second sensor is located in an upper part of the respective mixing vessel.

The control system is arranged to supply at least some water to the or each mixing vessel prior to delivering particulate material to the or each mixing vessel. The control system controls operation of the or each mixing device.

The or each mixing device preferably includes a mechanical agitator, such as a rotary member. The mixing device includes a drive unit for driving the mechanical agitator. In preferred embodiments, the drive unit includes a motor that is arranged to rotate the mechanical agitator. The or each mixing device can include at least one of a circulation pump and a vortex generator.

The control system controls operation of the mechanical agitator by controlling the drive unit, for example the control unit may control the rate at which the mechanical agitator rotates and/or the direction of rotation. The control system includes a timer and operates the or each mixing device for a set period of time when producing a batch of liquid.

The or each mixing device is mounted to a frame by damping means. This reduces the impact of vibrations from the mixing device on the weighing system.

The control system is arranged to actuate the or each mixing device prior to delivering particulate material to the mixing vessel. The control system actuates the mechanical agitator prior to delivering particulate material to the or each mixing vessel, this provides turbulence in the water which assists the particulate material to dissolve.

The or each mixing vessel includes a discharge valve for discharging liquid from the mixing vessel, and the control system is arranged to control operation of the discharge valve.

The control system is arranged to automatically open the discharge valve at the end of a mixing process, for example in response to the set mixing time period elapsing.

The apparatus includes at least one storage vessel, which is connected in series with the mixing vessel discharge valve, and is arranged for storing liquid produced in the mixing vessel. The mixing vessel is connected to the storage vessel by piping. The or each storage vessel provides an intermediate store for the liquid. The liquid is stored temporarily in the storage vessel until it is required for use in the pellet coating process. At least one, and preferably each, storage vessel is located below the level of the mixing vessel, when the apparatus is in its normal operating orientation. This enables a gravity feed to be provided between the mixing vessel and storage vessel.

The or each storage vessel includes a low level sensor located towards its base, and the control system is arranged to determine from the signals received from the sensor that a low level condition has occurred. The control system may use this signal, for example to determine initiate a new batch of liquid.

The apparatus includes at least one pump arranged to pump liquid from the or each mixing vessel. Liquid is pumped from the vessel via the discharge valve. The pump is arranged to pump the liquid from the mixing vessel to the storage vessel via the piping.

The apparatus includes at least one pump arranged to pump liquid from the storage vessel to downstream apparatus, such as a pellet coating station. The liquid is applied to pellets at the pellet coating station. The output side of the or each storage vessel is connected to at least one supply line for delivering liquid to a pellet coating process, or an intermediate storage vessel. The pump is arranged to pump the liquid along the or each supply line.

At least one, and preferably each, of the feeders includes a vibratory feeder. This is particularly useful for delivering particulate materials to the mixing vessel. For example, the or each feeder can include a support member, such as a chute, for carrying the particulate material and a vibration unit for vibrating the support member. The vibration unit preferably includes a vibrating magnet. At least one, and preferably each, of the feeders can include a weighing belt. At least one, and preferably each, of the feeders can include a weighing cup and screw feed device.

The or each storage vessel for the particulate material(s) includes a hoper.

The or each particulate material storage vessel includes at least one wall, which is inclined to a horizontal axis. The wall is inclined steeply. The angle subtended between the horizontal axis and the inclined wall is typically greater or equal to 60 degrees, preferably 70 degrees and more preferably still 80 degrees. This helps the particulate material to flow out of the storage vessel. The or each weighing system is mounted to a frame by a damping arrangement. The damping arrangement reduces the effect of vibrations, for example vibrations generated by the or each feeder, mixing device and pump on the operation of the weighing system.

The apparatus includes a cleaning system arranged to clean at least one of the mixing vessel(s) and storage vessel(s) with water from the water supply means, wherein the control system is arranged to control operation of the cleaning system.

The user interface is arranged to enable a user to specify the period of time for which the cleaning system operates.

The apparatus includes a main frame arranged to support, either directly or indirectly, at least some, and preferably each, of the following equipment: the or each mixing vessel; the or each storage vessel; the or each particulate material storage vessel; the or each feeder; the weighing system; and the or each mixing device. The apparatus can be in the form of a standalone unit, which can be retro-fitted to an existing pellet manufacturing system. The water supply means includes suitable connectors for connecting to a water source such as a mains supply or storage tank.

The or each pump is mounted on a sub-frame, which is separate from the main frame. This isolates vibrations generated by the pumps from the equipment mounted on the main frame, in particular the weighing system. The sub-frame is arranged to be secured to a floor, for example by bolts. The main frame is mounted on dampers. This reduces vibrations transmitted to the frame, and equipment mounted thereon.

The apparatus includes a main housing arranged to house at least some, and preferably each, of the following equipment: the or each mixing vessel; the or each storage vessel; the or each particulate material storage vessel; the or each feeder; the weighing system; the control system and the or each mixing device.

The apparatus includes an air conditioning unit to condition the air within the apparatus housing. Preferably, the air conditioning unit is operable to keep the temperature of the atmosphere within the housing below a predetermined temperature, in particular below a temperature which is not higher than 25 °C and/or to keep the relative humidity of the atmosphere within the housing below a predetermined relative humidity, in particular below a relative humidity which is not higher than 30%.

A door can be provided for accessing the equipment stored in the housing. The control system user interface is located outside of the main housing, for example in a separate control system housing, which is attached to the main housing. The control system housing also stores a PLC.

The apparatus includes a first particulate material. The first particulate material is in the form of a powder and/or granules. The first particulate material is dry. The first particulate material is water soluble. The first particulate material includes at least one enzyme. For example, the first particulate material can include phytase. This is commercially available as a concentrated highly water soluble enzyme powder under the name OptiPhos®, from Huvepharma®.

The apparatus can include a second particulate material. The second particulate material is in the form of a powder and/or granules. The second particulate material is dry. The second particulate material is water soluble. The second particulate material includes at least one enzyme. For example, the second particulate material can include xylanase. This is commercially available as a concentrated highly water soluble enzyme powder under the name Hostazym®, from Huvepharma®. According to another aspect of the invention there is provided a system for coating pellets, such as feed pellets, including: apparatus for manufacturing at least one liquid; a pellet source; at least one pellet coating device; means for feeding at least one liquid from the manufacturing apparatus to the pellet coating device; wherein the pellet coating device is arranged to apply the or each liquid to at least some of the pellets received from the pellet source.

The apparatus for manufacturing at least one liquid can be arranged according to any configuration described herein, for example as defined in claims 1 to 63. In preferred embodiments the liquid is pumped from the manufacturing apparatus to the pellet coating device. The manufacturing apparatus is connected to the pellet coating device by a supply line, which may include one or more intermediate storage vessels.

According to another aspect of the invention there is provided a method for manufacturing a liquid including at least one enzyme, the method including: storing in a first storage vessel a first particulate material, which includes a first enzyme; supplying water to a mixing vessel; actuating a mixing device; a feed system feeding first particulate material to the mixing vessel; providing weighing means; a control system receiving signals from the weighing system and controlling operation of at least part of a feed system according to the signals received from the weighing system to control the mass of first particulate material fed to the mixing vessel.

Advantageous optional features of preferred embodiments are disclosed in the dependent claims and in the statements of invention below.

The method uses apparatus according to any configuration described herein, for example in as defined in any one of claims 1 to 63, to manufacture the liquid.

The first particulate material is in the form of a powder and/or granules. The first particulate material is dry. The first particulate material is water soluble. The first particulate material includes at least one enzyme. For example, the first particulate material can include phytase. This is commercially available as a concentrated highly water soluble enzyme powder under the name OptiPhos®, from Huvepharma®.

The method includes providing a first feeder arranged to feed first particulate material from the first storage vessel to the weighing system; and the control system ceasing feeding first particulate material in response to determining from signals received from the weighing system that a target mass of first particulate material is achieved. For example, by ceasing operation of the first feeder.

The method includes providing a second feeder arranged to feed first particulate material from the weighing system to the mixing vessel. The method includes the control system feeding the first particulate material to the mixing vessel in response to determining from the signals received from the weighing system that the target mass of first particulate material is detected by the weighing system.

The method includes providing a second storage vessel for storing a second particulate material.

The second particulate material is in the form of a powder and/or granules. The second particulate material is dry. The second particulate material is water soluble. The second particulate material includes at least one enzyme. For example, the second particulate material can include xylanase. This is commercially available as a concentrated highly water soluble enzyme powder under the name Hostazym®, from Huvepharma®.

The method includes feeding second particulate material to the weighing system; and the weighing system determining the mass of the second particulate material fed thereto. The method includes feeding the second particulate material from the weighing system to at least one mixing vessel. The method includes providing a first feeder arranged to feed second particulate material to the weighing system; and feeding second particulate material to the weighing system.

The method includes the control system ceasing feeding second particulate material in response to determining from signals received from the weighing system that a target mass of second particulate material is achieved. For example, ceasing operation of the second feeder.

The method includes providing a second feeder arranged to feed second particulate material from the weighing system to at least one mixing vessel; and including feeding second particulate material to at least one mixing vessel.

The method includes the control system actuating the second feeder in response to the control system determining from the signals received from the weighing system that the target mass of second particulate material is detected by the weighing system. The method includes the control system adjusting the rate at which the or each first feeder dispenses particulate material to the weighing system. This helps to improve the dispensing accuracy.

The method includes preferably keeping the temperature of said first particulate material and, when present, of said second particulate material below a predetermined temperature, in particular below a temperature which is not higher than 25°C. The method further includes preferably keeping the relative humidity of the atmosphere surrounding said first particulate material and, when present, of said second particulate material, below a predetermined relative humidity, in particular below a relative humidity which is not higher than 30%.

The method includes providing a user input device and memory.

The method includes the user specifying at least one of the following to create a batch of liquid: the quantity of the first particulate material to be delivered to the or each mixing vessel; the quantity of the second particulate material to be delivered to the or each mixing vessel; the quantity of water supplied to the or each mixing vessel; and the mixing time for the or each mixing device.

The method includes the user storing in the memory at least one formula for producing a batch of liquid. The user inputs values for at least some of the following parameters when defining a formula: the choice of particulate material; the quantity of water; the quantity of particulate material; the ratio of particulate material to water; the tolerance for the quantity of particulate material; and the mixing time.

The control system includes a display device, which displays at least one of the following: the set quantity of the first particulate material to be delivered to the or each mixing vessel; the quantity of first particulate material already delivered; the current value of first particulate material from the weighing system; the set quantity of the second particulate material to be delivered to the or each mixing vessel; the quantity of second particulate material already delivered; the current value of second particulate material from the weighing system; the set quantity of water supplied to the or each mixing vessel; the quantity of water currently delivered to the or each mixing vessel; the set mixing time for the or each mixing device; and the mixing time elapsed since commencing the mixing process.

The method includes providing water supply means and at least one flowmeter. The control system controls the quantity of water supplied to the or each mixing vessel according to signals received from the at least one flowmeter.

The water supply means includes at least one valve. The control system controls operation of at least one valve according to signals received from the flowmeter.

The or each mixing vessel includes a liquid detection sensor, and the control system actuates the mixing device in response to the first sensor detecting the presence of liquid in the mixing vessel, and preferably detecting the presence of water. The control system distinguishes between liquid manufacture operations and cleaning operations. The or each mixing device is not actuated during a cleaning operation.

The method includes the control system supplying at least some water to the or each mixing vessel prior to delivering particulate material to the or each mixing vessel. The method includes providing at least one mixing device having a mechanical agitator, such as a rotary member, and a drive unit for driving the mechanical agitator. The control system includes a timer. The control system operates the mechanical agitator for a set period of time.

The method includes the control system actuating the or each mixing device prior to delivering particulate material to the mixing vessel.

The method includes providing a discharge valve for discharging liquid from the or each mixing vessel, and the control system automatically opening the discharge valve at the end of the mixing process, for example in response to the mixing device ceasing operation.

The method includes providing at least one storage vessel, which is arranged for storing liquid produced in at least one mixing vessel. At least one storage vessel is connected in series with at least one mixing vessel discharge valve. The or each storage vessel includes a low liquid level sensor located towards its base. The method includes the control system manufacturing a new batch of liquid in response to signals received from the low liquid level sensor.

The method includes providing at least one pump arranged to pump liquid from the or each mixing vessel, and pumping liquid from the or each mixing vessel. The method includes providing at least one pump arranged to pump liquid from at least one storage vessel to downstream apparatus, such as a pellet coating station, and pumping liquid from the at least one storage vessel.

At least one, and preferably each, of the first feeders includes a vibration unit. The method includes feeding particulate material to the weighing system by actuating the vibration drive unit.

At least one, and preferably each, of the second feeders includes a vibration unit. The method includes feeding particulate material to the mixing vessel by actuating the vibration drive unit.

The method includes providing a cleaning system arranged to clean at least one of: the mixing vessel(s) and the storage vessel(s); and the control system cleaning the or each vessel. The user specifies the period of time for which the cleaning system operates, via the user interface.

According to another aspect of the invention there is provided a method for coating pellets, for example pellets used to feed animals, including: manufacturing a liquid which includes at least one enzyme by means of manufacturing apparatus; providing at least one pellet coating device and a supply line which connects the manufacturing apparatus to the at least one pellet coating device; supplying the liquid to at least one pellet coating device, via the supply line; supplying pellets to the at least one pellet coating device; and applying the liquid to at least some of the pellets. The manufacturing apparatus for manufacturing a liquid which includes at least one enzyme, can be arranged according to any configuration described herein, for example as defined in any one of claims 1 to 63. Additionally, or alternatively, the liquid can be manufactured according to a method as defined in any one of claims 63 to 98. The method includes providing the apparatus in the form of a standalone unit; and includes retro-fitting an existing pellet manufacturing system with the apparatus.

According to another aspect of the invention there is provided apparatus for manufacturing a liquid, wherein the apparatus is arranged for inclusion in a pellet manufacturing system to supply the liquid to downstream apparatus such as a pellet coating station, and includes: a mixing vessel; a mixing device for mixing substances located in the mixing vessel; water supply means arranged to supply water to the mixing vessel; a first storage vessel for storing a first particulate material; a weighing system; a feed system for feeding first particulate material to the mixing vessel; and a control system. Advantageously the apparatus can be arranged according to any configuration described herein. For example, the control system can be arranged to receive signals from the weighing system and to control operation of at least part of the feed system according to the signals received from the weighing system to deliver a target mass of first particulate material to the mixing vessel. The apparatus can include a second storage vessel for storing a second particulate material. The weighing system can be arranged to weigh the second particulate material. The feed system can be arranged to feed the second particulate material to the mixing vessel. The control system can be arranged to control operation of at least part of the feed system according to the signals received from the weighing system to deliver a target mass of second particulate material to the mixing vessel. The first particulate material includes a first enzyme. The second particulate material includes a second enzyme. A batch of liquid enzyme produced by the apparatus includes at least one of the first and second enzymes.

According to another aspect of the invention there is provided a system for coating pellets, such as feed pellets, including: apparatus for manufacturing at least one liquid enzyme; a pellet source; at least one pellet coating device; means for feeding at least one liquid enzyme from the manufacturing apparatus to the pellet coating device; wherein the pellet coating device is arranged to apply the or each liquid enzyme to at least some of the pellets received from the pellet source. Advantageously the apparatus for manufacturing at least one liquid enzyme can be arranged according to any configuration described herein. An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a diagrammatic representation of a prior art PPLA system;

Figure 2 is a diagrammatic representation of a PPLA system according to the invention, which includes apparatus for producing liquid enzyme;

Figure 3 is a diagrammatic representation of a first embodiment of the production apparatus of Figure 2, which is used to prepare liquid enzyme;

Figure 4 is a detailed view of part of a feed system in the apparatus of Figure 3, which feeds particulate material from a storage bin to scales, and from the scales to a mixing vessel;

Figure 5 is a detailed view of a part of a mixing vessel in the apparatus of Figure 3;

Figure 6 is a diagrammatic representation of a Programmable Logic Controller (PLC) used in the apparatus of Figure 3, the equipment controlled by the PLC, the sensors that provide data to the PLC, and a Human Machine Interface (HMI), which allows a user to set values for process parameters;

Figure 7 is a diagrammatic representation of a second embodiment of the production apparatus of Figure 2, which is used to prepare liquid enzyme;

Figure 8 is a diagrammatic representation of a PLC used in the apparatus of Figure 7, the equipment controlled by the PLC, the sensors that provide data to the PLC, and a Human Machine Interface (HMI), which allows a user to set values for process parameters;

Figure 9 is a detailed view of three pumps in the apparatus of Figure 7;

Figure 10 is a detailed view of part of feed system in the apparatus of Figure 7, which feeds particulate material from the storage bins to scales, and from the scales to a mixing vessel; and

Figure 11 is a detailed view of a part of a mixing vessel in the apparatus of Figure Figure 2 shows a PPLA system 1, in accordance with the invention, which includes a pellet silo 202; a pellet coating device 204 arranged to apply one or more liquids to pellets; a feeder 206 arranged to feed pellets from the silo 202 to the coating device 204; an enzyme dosing system 208; and apparatus 3 for manufacturing liquid enzyme. Thus the liquid enzyme is manufactured on site and the manufacturing apparatus is part of the PPLA system 1.

Figures 3 to 6 are diagrammatic representations of a first embodiment of the apparatus 3. The apparatus 3 includes a frame 5, which is preferably mounted on dampers; a storage bin 7 for storing particulate enzyme, for example in the form powder and/or granules; a mixing vessel 9; a feed system 11 for feeding enzyme particles from the storage bin 7 to the mixing vessel 9; a mixing device 13; a weighing system, including scales 17, which is arranged to weigh enzyme particles; a control system 19; and a water supply system 21 arranged to supply water to the mixing vessel 9.

The control system 19 includes a Programmable Logic Controller (PLC) 23 and a Human Machine Interface (HMI) 25.

The storage bin 7 is in the form of a hopper, and includes inclined lower surfaces 27,29 which are arranged to direct enzyme particles to an outlet 31. The storage bin 7 can be mounted on a scales 33, and/or can include at least one of a high level sensor 35 and a low level sensor 37. The scales 33, high level sensor 35 and/or low level sensor 37 is connected to the PLC 23. The PLC 23 is programmed to determine the amount of particles stored within the bin 7 according to the signals received from scales 29. The PLC 23 is arranged to issue an alert when it determines from the signals received form the scales that the amount of particles in the bin is outside predetermined values, for example if there is less power than a lower threshold value and/or more particles than an upper threshold value. The PLC 23 is programmed to issue an alert when it detects from the low level sensor 37 that the amount of particles in the bin has fallen below a predetermined level. The PLC 23 is programmed to issue an alert when it detects from the high level sensor 35 that the amount of particles in the bin is above a predetermined level.

The feed system 11 includes a first feeder which is arranged to transport enzyme particles from the storage bin 7 to the scales 17. The first feeder includes a first chute 39 for transporting particles from the storage bin 7 to the scales 17 and a vibratory drive unit 41, which is arranged to vibrate the storage bin 7 and first chute 39 to transport particles to the scales 17. The vibratory drive unit 41, preferably includes a vibrating magnet. The vibratory drive unit 41 is controlled by the PLC 23. The PLC 23 can be programmed to adjust the rate at which particulate material is delivered to the scales 17 to ensure accuracy by adjusting the speed of the vibratory drive unit 41.

The feed system 11 includes a second feeder, which is arranged to transport enzyme particles from the scales 17 to the mixing vessel 9. The second feeder includes a second chute 45 and a vibratory drive unit 47, which is arranged to vibrate the second chute 45 to transport particles to the mixing vessel 9.

The second chute 45 is mounted on the scales 17. The scales 17 sits under the second chute 45. A first part 46 of the second chute sits under an end of the first chute 39, and is arranged to receive particulate material therefrom. A second part 48 of the second chute overhangs the mixing vessel 9. The scales 17 is connected to the PLC 23. The PLC 23 is able to determine from the signals received from the scales the mass of enzyme particles received from the storage bin. The PLC 23 is programmed to control operation of the vibratory unit 41 to deliver a target mass of enzyme particles to the second chute 45, and hence scales 17. The PLC 25 compares the output reading from the scales with a target mass value stored in memory. When the output reading is substantially equal to the target mass value, within an acceptable tolerance, the PLC determines that the target mass is achieved, and the PLC 23 switches off vibratory drive unit 41. The target mass value is typically set by a user via the HMI 25.

The scales 17 is mounted to the frame 5 via a damping system 43 in order to reduce the effect of vibrations on the scales 17. This helps to improve the accuracy of the scales 17. If the scales is not providing a stable signal to the PLC 23, for example due to a high level of vibrations, the PLC 23 issues an alert.

The vibratory drive unit 47 is controlled by the PLC 23. The PLC 23 controls operation of the vibratory drive unit 47 to deliver the target mass of particles to the mixing vessel 9. The PLC 23 is programmed to adjust the rate at which particulate material is delivered to the mixing vessel 9.

Since the second chute 45 sits on the scales 17, the PLC 23 is able to determine from the scales when substantially all of the particulate material has been delivered to the mixing vessel 9.

The water supply system 21 includes a control valve 49, which is arranged to control the flow of water into the mixing vessel 9, via an inlet 22, and a flow meter 51, which is arranged to monitor the quantity of water delivered to the mixing vessel. The control valve 49 is controlled by the PLC 23. The PLC 23 is arranged to receive signals from the flow meter 51. The PLC 23 is arranged to control operation of the control valve 49, in accordance with signals received from the flow meter 51, to deliver a target volume (or mass) of water to the mixing vessel. The PLC 23 compares the output reading from the flow meter 51 with a target volume (or mass) value stored in memory. When the output reading is substantially equal to the target value, within an acceptable tolerance, the PLC determines that the target volume (or mass) is achieved, and the PLC 23 closes the control valve 49. The target volume (or mass) of water is typically set by a user via the HMI 25.

For at least some processes, the PLC 23 is programmed to deliver at least some of the water to the mixing vessel 9 prior to delivering enzyme particles to the mixing vessel 9. The inventors have found that this reduces the possibility of some of the particles not dissolving in the water, for example due to clumping.

The mixing device 13 includes a rotary agitator 53, for example in the form of a paddle or rotor, and a drive unit 55, typically an electric motor that is arranged to drive the rotary agitator. The PLC 23 controls operation of the mixing device 13, for example the speed and/or direction of rotation of the rotary agitator 53. For at least some processes, the PLC 23 can be programmed to change the direction and/or speed of rotation of the agitator 53. For at least some processes, the PLC 23 can be programmed to actuate the rotary agitator 53 prior to delivering enzyme particles to the mixing vessel 9. The inventors have found that this reduces the possibility of some of the particles not dissolving in the water, for example due to clumping. Typically, the mixing device 13 is operated for a set period of 'mixing time' during a batch making process. The start of the mixing period is typically taken from the time at which the PLC 23 determines that substantially all of the particulate material is delivered to the mixing vessel 9. Of course, the mixing device is usually operating prior to commencement of the mixing period.

The mixing device 13 is mounted to the frame 5 via a damping system 57, such as rubber shock absorbers, this reduces vibrations transmitted to the frame 5, which can affect operation of the scales 17,33.

The mixing vessel 9 is provided to mix the particulate enzyme with water thereby producing a liquid enzyme. The mixing vessel 9 is typically a stainless steel tank, having a slightly rounded or tapered base. The mixing vessel 9 is attached to the frame 5. The mixing vessel 9 is located below the second chute 45. The mixing vessel 9 includes a lid 59 having an opening 61 located below the end 48 of the second chute 45. Particulate enzyme falls into the mixing vessel 9 via the opening 61. The mixing device drive unit 55 is located above the mixing vessel 9, the rotary agitator 53 protruding downwardly therefrom into the mixing vessel 9.

The mixing vessel includes a high liquid level sensor 63 and a low liquid level sensor 65. The sensors 63,65 are connected to the PLC 23. The PLC 23 is programmed to start operation of the mixing device 13 in response to the low level indicator detecting the presence of water. The PLC 23 is programmed to issue an alert when it detects from the high liquid level sensor 33 that the volume of water in the mixing vessel 9 is above a predetermined level.

A discharge valve 67 is located towards the base of the mixing vessel 9. The PLC 23 controls operation of the discharge valve 67. During a mixing operation the discharge valve is closed. When the mixing operation is completed, the PLC 23 opens the discharge valve 67. This enables the liquid enzyme to flow out of the mixing vessel 9.

A storage tank 69 is located below the mixing vessel 9. The storage tank 69 is connected to the discharge valve 67 via piping 71. When the discharge valve 67 is opened the liquid enzyme flows, for example under the influence of gravity, through the piping 71 into the storage tank 69 for intermediate storage. A pump 73 can be provided to pump the liquid enzyme from the mixing vessel 9 to the storage tank 69. A pump 73 would be required if the storage tank 69 was located above the level of the mixing vessel 9.

A liquid level sensor 75 is provided in the piping 71. The liquid level sensor 75 is connected to the PLC 23. The PLC 23 is able to determine from the signals received from the liquid level sensor 75, when no liquid is present, and hence all of the liquid has drained from the mixing vessel 9, and uses this signal to close the discharge valve 67, in readiness for the next batch.

The storage tank 69 provides a place to store the liquid enzyme until it is transferred to the enzyme dosing system 208, for use in a pellet coating process. The storage tank 69 is typically a stainless steel tank, having a slightly rounded or tapered base. The storage tank 69 is attached to the frame 5.

The storage tank 69 includes a high liquid level sensor 77 and a low liquid level sensor 79. The sensors 77,79 are connected to the PLC 23. The PLC 23 may be programmed to start a new batch in response to the low liquid level sensor 79 detecting that the liquid level in the tank 69 has fallen to a predetermined low level. The PLC 23 may be programmed to dry- run a safety device in response to the high liquid level sensor 77 detecting that the liquid level in the tank 69 has risen to a predetermined high level.

A discharge valve 81 is located towards the base of the storage tank 69. The PLC 23 controls operation of the discharge valve 81. A pump 83 can be provided to pump the liquid enzyme from the storage tank 69 to the enzyme dosing system 208.

The apparatus includes a Clean in Place (CIP) system 85. The CIP system is used to rinse clean water through at least one of the mixing vessel 9 and storage tank 69, to clean the receptacle prior to producing a new batch of liquid enzyme. The CIP system 85 includes a control valve 87 and a flow meter 89. The PLC 23 controls operation of the control valve 87 and receives signals from the flow meter 89. The CIP system 85 includes piping 91 and a discharge nozzle 93 for each vessel 9 / tank 69 to be cleaned. The PLC 23 can be programmed to clean at least one of the vessel 9 and tank 69 automatically, for example according to a schedule and/or in response to an event occurring such as the end of a batch and/or a change of enzyme particulate. Additionally, or alternatively, the PLC 23 can be arranged to actuate the CIP system 85 in response to a manual request by a user.

The user is able to set the period of time for which the CIP system 85 operates via the HMI 25. During a cleaning operation the PLC 23 uses inputs from the vessel / tank sensors to ensure that water does not over flow from the tank / vessel. Dirty water from the cleaning operation is directed to a drain.

The PLC 23 can be arranged to operate the valves 67,81,49,87; the pumps 73,83; and the drive units 41,55,47 automatically and/or according to user inputs to the HMI 25. The HMI 25 includes a visual display. The display is arranged to display the following information to a user: the set quantity of the first particulate material to be delivered to the mixing vessel; the quantity of first particulate material already delivered; the current value of first particulate material from the weighing system; the set quantity of the second particulate material to be delivered to the mixing vessel; the quantity of second particulate material already delivered; the current value of second particulate material from the weighing system; the set quantity of water supplied to the mixing vessel; the quantity of water currently delivered to the mixing vessel; the set mixing time for the mixing device; and the mixing time elapsed since commencing the mixing process.

Alerts issued by the PLC 23 can be visual and/or audible. Preferably the alert is provided by the HMI 25 via its display.

Optionally, a housing (not shown) can be provided for the apparatus 3. For example, a plurality of panels can be fitted to the frame 5 to form the housing. The housing may include a door or hatch to access the apparatus. A seal can be provided around the door to ensure the interior of the housing remains dust free. Other seals can be fitted between panels, if necessary. Typically, the control system 19 is located in an additional housing, which is attached to the frame (see Figures 3 and 7).

It will be appreciated that the apparatus 3 can be retrofitted to an existing PPLA system or can be fully integrated into a new PPLA system. In use, the liquid is typically prepared around 12 to 24 hours prior to the pellet coating process taking place.

The user loads the appropriate particulate material into the storage bin 7. The particulate material is in the form of a powder and/or granules. Typically the particulate material is dry, is water soluble, and includes at least one enzyme. For example, the particulate material can comprise phytase, which is in the form of a concentrated highly water soluble enzyme powder. This particulate material is sold, for example under the name OptiPhos® and is commercially available from Huvepharma®. The particulate material can comprise xylanase, which provided in the form of a concentrated highly water soluble enzyme powder. This particulate material is sold, for example under the name Hostazym® and is commercially available from Huvepharma®.

Other particulate materials can be used.

The user inputs appropriate values into the HMI 25, thereby programming the PLC 23 with process operating values. Typically, the user selects a formula from the devices 25 memory. If an appropriate formula is not available, the user can program the HMI 25 with a new formula.

The formula typically requires values for the following:

1. a total liquid value [litres]: the amount of water that is supplied to the mixing vessel for the batch;

2. a ratio value [g/litre]: the ratio of enzymes / to water that should be supplied to the mixing vessel for the batch;

3. a tolerance value [%]: tolerance for enzyme dosing; and

4. a mixing time value [seconds]: mixing time for the batch after all the water and enzyme has been supplied to the mixing vessel. The formula may also include at least one identifier such as a formula number and/or formula name.

The formula may also include a storage bin selection and a storage tank selection (see second embodiment below). From the 'total liquid value' and the 'ratio value', the PLC 23 is able to determine a target mass of enzyme particles that have to be delivered to the mixing vessel 9.

When the values have been set, the process is initiated.

The PLC 23 opens control valve 49 and supplies water to the mixing vessel 9. The PLC 23 closes the control valve 49 when it determines from signals received from the flow meter 51 that the total liquid value of water is supplied to the mixing vessel 9.

The PLC 23 actuates the mixing device drive unit 55 in response to receiving a single from the mixing vessel low liquid level sensor 65, which indicates that there is some water in the vessel 9. The PLC 23 actuates the vibratory drive unit 41 to dose dry enzyme particles to the scales 17. In response to the PLC 23 determining from the scales 17 that the target mass value of enzyme particles has been received by the scales 17, the PLC 23 deactivates the vibratory drive unit 41 and activates vibratory drive unit 47.

When the second feeder has delivered all (within tolerance) of the particulate enzyme material to the mixing vessel 9, the mixing device mixes the water and enzyme for a period of time equal to the mixing time value.

When the mixing time has elapsed, the PLC23 opens the discharge valve 67, and optionally actuates the discharge pump 73, to transfer the liquid enzyme to the storage tank 69. The PLC 23 determines that the apparatus is in a state of readiness to produce another batch of liquid enzyme in response to a signal from the level indicator 75. Of course, if a different type of liquid enzyme is required, the user can select a cleaning operation before commencing the next batch.

The liquid enzyme 69 remains in the storage tank 69 until it is transferred to downstream apparatus, such as enzyme dosing apparatus 208 in a pellet coating process.

The user has the option of selecting the number of batches to be produced. If sufficient storage capacity is available, the apparatus can produce a plurality of batches, one after the other, until all of the storage capacity is used up. The PLC 23 can use the signal from the low liquid level sensor 79 in the storage tank to determine that sufficient storage capacity is available to produce a new batch.

Figures 7 to 11 are diagrammatic representations of a second embodiment of the apparatus 3. The apparatus 3 is similar to the first embodiment, except in the following respects.

The apparatus includes a plurality of storage bins 7,7b for storing dry enzyme particles (two storage bins 7,7b are shown in Figure 7). This enables a user to store two or more different types of enzyme particles, or to have an increased capacity for one type of enzyme particles. For example, a first storage bin 7 may store a particulate material including phytase, such as OptiPhos®. The second storage bin 7b may also store a particulate material including phytase, such as OptiPhos®, or may store a different particulate material, for example a particulate material including xylanase, such as Hostazym®.

Each of the storage bins 7,7b provided is similarly arranged to the first embodiment, for example can be mounted on a scales 33,33b and/or can include at least one of a high level sensor 35 and a low level sensor 37.

Each of the storage bins 7,7b is provided with its own first feeder which is arranged to transport enzyme particles from the storage bin 7,7b to the scales 17. The first feeder includes a first chute 39,39b for transporting particles from the storage bin 7,7b to the scales 17 and a vibratory drive unit 41,41b, which is arranged to vibrate the storage bin 7,7b and first chute 39,39b to transport particles to the scales 17.

The PLC 23 controls operation of the first feeders independently of each other.

For each additional bin 7b, a target mass value can be set or calculated to determine the mass of particulate material to be delivered to the mixing vessel during a liquid manufacturing process. The PLC 23 controls operation of the first feeder for the additional bin 7b in a similar manner to the sole bin 7 in the first embodiment.

Each of the storage bins 7,7b is provided with its own second feeder. Each second feeder includes a second chute 45,45b, which is arranged to transport enzyme particles from the scales 17 to the mixing vessel 9. At least one vibratory drive unit 47,47b is provided to vibrate the or each second chute 45,45b to transport particles to the mixing vessel 9. In some arrangements, each chute 45,45b is provided with its own vibratory drive unit 47,47b. The PLC 23 controls operation of the second feeders independently of each other. In other arrangements, one vibratory drive unit 47 is provided to drive a plurality of second chutes 45,45b.

The apparatus 3 includes a plurality of storage tanks 69 (two storage tanks 69,69b are shown in Figure 7). The outlet of the mixing vessel 9 is connected to each of the storage tanks 69,69b, and the PLC 23 is arranged to selectively direct liquid enzyme to any of the available storage tanks 69,69b by controlling operation of a valve. The selection can be made automatically or in response to an input made by a user.

The apparatus 3 includes a pump set having a plurality of storage tank discharge pumps 83, 83b, 83c for transferring liquid from the storage tanks 69,69b to downstream apparatus. Liquid enzyme can be transferred between the storage tanks 69,69b via a pipe, using the pump set, should that be necessary.

The pumps 83, 83b, 83c are mounted on a sub-frame 5b, which is separate from the main frame 5. This is to isolate vibrations from the pumps 83, 83b, 83c from the main frame 5. The sub-frame 5b should be secured to the floor when the apparatus 3 is installed.

During a process for making a liquid, particulate material can be transferred to the mixing vessel 9 from any one of the storage bins 7,7b, or from any combination of the available storage bins 7,7b.

Although the present invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Furthermore, it will be apparent to the skilled person that modifications can be made to the above embodiment that fall within the scope of the invention.

For example, other particulate materials can be used with the apparatus, this includes enzyme particulate materials, such as flavourings, colourings, and fragrances. Moreover, the liquid prepared by the apparatus can be sprayed on feed which is not in the form of pellets and which can be fed for example immediately to the animals.

The number of storage bins, and associated equipment, can be increased.

The number of storage tanks, and associated equipment, can be increased. A scanning device can be provided to open at least one hoper lid. Each hopper can be provided with a scanning device.

At least one, and preferably each of, the hoppers includes a dust filter. The dust filter is preferably located in an upper region of the hopper. The dust filter is preferably arranged to draw air into the hopper, and not outwards. The dust filter is arranged to limit the amount of dust which escapes from the hopper.

The second feeder can include at least one weighing belt delivery system. For example, as an alternative to one of the vibrating chutes described above. The or each weighing belt includes a weighing system for weighing particulate material deposited thereon. The weighing belt delivers the particulate material to the mixing vessel. The second feeder can include at least one weighing cup and a transport screw. For example, as an alternative to one of the vibrating chutes described above. Particulate material is deposited into the weighing cup and a weighing device measures the quantity received. The transport screw transports the particulate material from the weighing cup to the mixing vessel. A circulation pump can be provided to mix the particulate material and water in the mixing vessel. In addition, or as an alternative, to the mixing device 13.

A device can be provided which generates a vortex to mix the particulate material and water in the mixing vessel. In addition, or as an alternative, to the mixing device 13.

At least one additional mixing vessel can be provided. For example, a first particulate material stored in a first hopper is transported by the feed system to the first mixing vessel. A second particulate material stored in a second hopper is transported by the feed system to the second mixing vessel. The or each additional mixing vessel can be arranged similarly to the mixing vessel described above, for example is can be supplied with water by the water, include at least one mixing device, high level sensor, low level sensor and/or a discharge valve. For embodiments including at least one additional mixing vessel it is preferable to provide at least two storage tanks. An air conditioning unit can be provided to condition the air within the apparatus housing. Preferably the air conditioning unit is located towards an upper part of the housing. The air conditioning unit is operable to keep the temperature of the atmosphere within the housing below a predetermined temperature, in particular below a temperature which is not higher than 25°C and/or to keep the relative humidity of the atmosphere within the housing below a predetermined relative humidity, in particular below a relative humidity which is not higher than 30%.

The housing can be arranged in an airtight manner, for example by providing appropriate seals and joints. This isolates from the outside environment the equipment within the housing and the materials stored therein. The control system, for example the PLC 23, can include a data connector, such as an Ethernet connector or a wireless data connection, to enable the PLC 23 to be controlled remotely.

The control system, for example the PLC 23, can include a report module. The report module is arranged to obtain and report process data to a user. The housing can include a plurality of doors. For example, a first door can be provided at the front of the housing and a second door at the rear of the housing.

A connector can be provided on at least one of the hoppers, and preferably on each of the hoppers. The or each connector is preferably provided at an upper part, for example the top, of the hopper. The connector is arranged to receive a recipient, such as a container. The connector enables the container to be attached to the hopper. The purpose of the connector is to enable the container to be emptied without making any dust, or a minimal amount of dust.

Claims

1. A system for coating pellets, including: apparatus for manufacturing at least one liquid; a pellet source; at least one pellet coating device; means for feeding at least one liquid from the manufacturing apparatus to the pellet coating device; wherein the pellet coating device is arranged to apply the or each liquid to at least some of the pellets received from the pellet source and wherein said apparatus includes: a mixing vessel; a mixing device for mixing substances located in the mixing vessel; water supply means arranged to supply water to the mixing vessel; a first storage vessel for storing a first particulate material; a weighing system; a feed system for feeding first particulate material to the mixing vessel; and a control system; wherein the control system is arranged to receive signals from the weighing system and to control operation of at least part of the feed system according to the signals received from the weighing system to deliver a target mass of first particulate material to the mixing vessel.

2. A pellet coating system according to claim 1, wherein the feed system is arranged to feed first particulate material to the weighing system, and to feed first particulate material from the weighing system to the mixing vessel.

3. A pellet coating system according to claim 2, wherein feed system includes a first feeder arranged to feed first particulate material from the first storage vessel to the weighing system and the control system is arranged to control operation of the first feeder according to signals received from weighing system.

4. A pellet coating system according to claim 2 or 3, wherein the control system is arranged to cease feeding first particulate material to the weighing system, in response to the control system determining from the signals received from the weighing system that the target mass of first particulate material has been fed to the weighing system.

5. A pellet coating system according to any one of claims 2 to 4, wherein the feed system includes a second feeder arranged to feed first particulate material from the weighing system to the mixing vessel.

6. A pellet coating system according to claim 5, wherein the control system is arranged to control operation of the second feeder according to signals received from weighing system.

7. A pellet coating system according to claim 5 or 6, wherein the control system is arranged to actuate the second feeder in response to the control system determining from the signals received from the weighing system that the target mass of first particulate material has been fed to the weighing system.

8. A pellet coating system according to any one of the preceding claims, including a second storage vessel for storing a second particulate material.

9. A pellet coating system according to claim 8, wherein the weighing system is arranged to weigh second particulate material, and the feed system is arranged to feed second particulate material to the weighing system and to feed second particulate material from the weighing system to the mixing vessel and/or an additional mixing vessel.

10. A pellet coating system according to claim 9, wherein the feed system includes a first feeder arranged to feed second particulate material from the second storage vessel to the weighing system.

11. A pellet coating system according to claim 10, wherein the control system is arranged to control operation of the first feeder according to signals received from weighing system.

12. A pellet coating system according to claim 10 or 11, wherein the control system is arranged to cease feeding second particulate material to the weighing system in response to the control system determining from the signals received from the weighing system that the target mass of second particulate material has been fed to the weighing system.

13. A pellet coating system according to any one of claims 8 to 12, wherein the feed system includes a second feeder arranged to feed second particulate material from the weighing system to the mixing vessel and/or an additional mixing vessel.

14. A pellet coating system according to claim 13, wherein the control system is arranged to control operation of the second feeder according to signals received from weighing system.

15. A pellet coating system according to claim 13 or 14, wherein the control system is arranged to actuate the second feeder in response to the control system determining from the signals received from the weighing system that the target mass of second particulate material has been fed to the weighing system.

16. A pellet coating system according to any one of claims 2 to 15, wherein the control system is arranged to adjust the rate at which the or each first feeder dispenses particulate material to the weighing system.

17. A pellet coating system according to any one of the preceding claims, wherein the weighing system includes a plurality of weighing devices.

18. A pellet coating system according to any one of the preceding claims, wherein the control system includes a user input device and memory, which enables a user to specify at least one of: the quantity of the first particulate material to be delivered to the mixing vessel; the quantity of the second particulate material to be delivered to the mixing vessel and/or an additional mixing vessel; the quantity of water supplied to the or each mixing vessel; and the mixing time for the or each mixing device.

19. A pellet coating system according to any one of the preceding claims, wherein the control system includes a display device, which is arranged to display at least one of the following: the set quantity of the first particulate material to be delivered to the mixing vessel; the quantity of first particulate material already delivered; the current value of first particulate material from the weighing system; the set quantity of the second particulate material to be delivered to the mixing vessel and/or an additional mixing vessel; the quantity of second particulate material already delivered; the current value of second particulate material from the weighing system; the set quantity of water supplied to the or each mixing vessel; the quantity of water currently delivered to the or each mixing vessel; the set mixing time for the or each mixing device; and the mixing time elapsed since commencing the mixing process.

20. A pellet coating system according to any one of the preceding claims, wherein the water supply means includes at least one flowmeter, and the control system is arranged to control the quantity of water supplied to the or each mixing vessel according to signals received from the at least one flowmeter.

21. A pellet coating system according claim 20, wherein the water supply means includes at least one valve, and the control system is arranged to control operation of at least one valve according to signals received from the flowmeter.

22. A pellet coating system according to any one of the preceding claims, wherein the or each mixing vessel includes a first sensor, and the control system is arranged to actuate the or each mixing device when the first sensor detects the presence of water in the or each mixing vessel.

23. A pellet coating system according to any one of the preceding claims, wherein the or each mixing vessel includes a second sensor, which is arranged as an overfill safety sensor, and the control system is arranged to cease supplying water to the or each mixing vessel in response to the second sensor detecting water.

24. A pellet coating system according to any one of the preceding claims, wherein the control system is arranged to supply at least some water to the or each mixing vessel prior to delivering particulate material to the or each mixing vessel.

25. A pellet coating system according to any one of the preceding claims, wherein the control system controls operation of the or each mixing device.

26. A pellet coating system according to any one of the preceding claims, wherein the or each mixing device includes a mechanical agitator and a drive unit for driving the mechanical agitator.

27. A pellet coating system according to claim 26, when dependent on claim 25, wherein the control system controls operation of the drive unit.

28. A pellet coating system according to any one of claims 25 to 27, wherein the control system includes a timer and operates the or each mixing device for a set period of time when producing a batch of liquid.

29. A pellet coating system according to any one of the preceding claims, wherein the or each mixing device is mounted to a frame by damping means.

30. A pellet coating system according to any one of the preceding claims, wherein the control system is arranged to actuate the or each mixing device prior to delivering particulate material to the or each mixing vessel.

31. A pellet coating system according to any one of the preceding claims, wherein the or each mixing vessel includes a discharge valve for discharging liquid from the or each mixing vessel, and the control system is arranged to control operation of the discharge valve.

32. A pellet coating system according to claim 31, wherein the control system is arranged to automatically open the or each discharge valve at the end of a mixing process.

33. A pellet coating system according to any one of the preceding claims, including at least one storage vessel, which is connected in series with at least one mixing vessel discharge valve, and is arranged for storing liquid produced in at least one mixing vessel.

34. A pellet coating system according to claim 33, wherein at least one storage vessel is located below the level of the mixing vessel when the apparatus is in its normal operating orientation.

35. A pellet coating system according to claim 33 or 34, wherein the or each storage vessel includes a low liquid level sensor located towards its base, and the control system is arranged to determine from the signals received from the sensor that a low liquid level condition has occurred.

36. A pellet coating system according to any one of the preceding claims, including at least one pump arranged to pump liquid from the mixing vessel.

37. A pellet coating system according to any one of the preceding claims, including at least one pump arranged to pump liquid from the storage vessel to said pellet coating device.

38. A pellet coating system according to any one of the preceding claims, wherein at least one, and preferably each, of the feeders includes a vibratory feeder.

39. A pellet coating system according to any one of the preceding claims, wherein the or each storage vessel for the particulate material includes a hoper.

40. A pellet coating system according to any one of the preceding claims, wherein the or each particulate material storage vessel includes at least one wall, which is inclined to a horizontal axis.

41. A pellet coating system according to any one of the preceding claims, wherein the or each weighing system is mounted to a frame by a damping arrangement.

42. A pellet coating system according to any one of the preceding claim, including a cleaning system arranged to clean at least one of the mixing vessel(s) and storage vessel(s) with water from the water supply means, wherein the control system is arranged to control operation of the cleaning system.

43. A pellet coating system according to claim 42, wherein the user interface is arranged to enable a user to specify the period of time for which the cleaning system operates.

44. A pellet coating system according to any one of the preceding claims, including a main frame arranged to support, either directly or indirectly, at least some, and preferably each, of the following equipment: the or each mixing vessel; the or each storage vessel; the or each particulate material storage vessel; the or each feeder; the weighing system; and the or each mixing device.

45. A pellet coating system according to claim 44, wherein the or each pump is mounted on a sub-frame, which is separate from the main frame.

46. A pellet coating system according to claim 44 or 45, wherein the main frame is mounted on dampers.

47. A pellet coating system according to any one of the preceding claims, including a main housing arranged to house at least some, and preferably each, of the following equipment: the or each mixing vessel; the or each storage vessel; the or each particulate material storage vessel; the or each feeder; the weighing system; the control system and the or each mixing device.

48. A pellet coating system according to claim 47, including an air conditioning unit to condition the air within the apparatus housing.

49. A pellet coating system according to claim 48, wherein the air conditioning unit is operable to keep the temperature of the atmosphere within the housing below a predetermined temperature, in particular below a temperature which is not higher than 25°C and/or to keep the relative humidity of the atmosphere within the housing below a predetermined relative humidity, in particular below a relative humidity which is not higher than 30%.

50. A pellet coating system according to any one of the claims 47 to 49, including at least one door for accessing the equipment stored in the housing.

51. A pellet coating system according to any one of the claims 47 or 50 when dependent on claim 18, wherein the control system user interface is located outside of the main housing, for example in a separate control system housing, which is attached to the main housing.

52. A pellet coating system according to any one of the preceding claims, including a first particulate material.

53. A pellet coating system according to claim 52, wherein the first particulate material is water soluble.

54. A pellet coating system according to claim 52 or 53, wherein the first particulate material includes at least one enzyme.

55. A pellet coating system according to any one of the preceding claims, including a second particulate material.

56. A pellet coating system according to claim 55, wherein the second particulate material is water soluble.

57. A pellet coating system according to claim 55 or 56, wherein the second particulate material includes at least one enzyme.

58. Apparatus for manufacturing a liquid, which apparatus includes: a mixing vessel; a mixing device for mixing substances located in the mixing vessel; water supply means arranged to supply water to the mixing vessel; a first storage vessel for storing a first particulate material; a weighing system; a feed system for feeding first particulate material to the mixing vessel; and a control system; wherein the control system is arranged to receive signals from the weighing system and to control operation of at least part of the feed system according to the signals received from the weighing system to deliver a target mass of first particulate material to the mixing vessel.

59. Apparatus according to claim 58, wherein the apparatus has the features as defined in any one of the claims 1 to 57.

60. Apparatus according to claim 58 or 59, wherein the apparatus is arranged for inclusion in a pellet coating system to supply the liquid to downstream apparatus, such as a pellet coating station.

61. Apparatus according to any one of the claims 58 to 60, including a main housing arranged to house at least some, and preferably each, of the following equipment: the or each mixing vessel; the or each storage vessel; the or each particulate material storage vessel; the or each feeder; the weighing system; the control system and the or each mixing device.

62. Apparatus according to any one of the claims 58 to 61, having a housing and including an air conditioning unit to condition the air within the apparatus housing.

63. Apparatus according to claim 62, wherein the air conditioning unit is operable to keep the temperature of the atmosphere within the housing below a predetermined temperature, in particular below a temperature which is not higher than 25°C and/or to keep the relative humidity of the atmosphere within the housing below a predetermined relative humidity, in particular below a relative humidity which is not higher than 30%.

64. A method for coating pellets, for example pellets used to feed animals, with a liquid enzyme, including: manufacturing a liquid including at least one enzyme with manufacturing apparatus; providing at least one pellet coating device and a supply line which connects the manufacturing apparatus to the at least one pellet coating device; supplying the liquid to at least one pellet coating device, via the supply line; supplying pellets to the at least one pellet coating device; and applying the liquid to at least some of the pellets manufacturing of said liquid includes: providing a first storage vessel; storing a first particulate material, which includes a first enzyme, in the first storage vessel; providing a mixing vessel; supplying water to the mixing vessel; providing a mixing device; actuating the mixing device to mix substances in the mixing vessel; providing a feed system and a weighing system; the feed system feeding first particulate material to the weighing system; the weighing system determining the mass of first particulate material fed thereto; a control system receiving signals from the weighing system and controlling operation of at least part of the feed system, according to the signals received from the weighing system, to control the mass of first particulate material fed to the weighing system; and feeding the first particulate material from the weighing system to the mixing vessel.

65. A method according to claim 64, wherein the feed system includes a first feeder arranged to feed first particulate material from the first storage vessel to the weighing system, and the control system ceasing feeding first particulate material in response to determining from signals received from the weighing system that a target mass of first particulate material is achieved.

66. A method according to claim 64 or 65, wherein the feed system includes a second feeder arranged to feed first particulate material from the weighing system to the mixing vessel.

67. A method according to claim 66, including the control system feeding the first particulate material to the mixing vessel in response to determining from the signals received from the weighing system that the target mass of first particulate material is received by the weighing system.

68. A method according to any one of claims 64 to 67, including providing a second storage vessel and storing a second particulate material in the storage vessel.

69. A method according to claim 68, wherein the second particulate material includes at least one enzyme.

70. A method according to any one of claims 64 to 69, wherein at least one of the first and second particulate materials is water soluble.

71. A method according to any one of claims 68 to 70, wherein the feed system includes a first feeder, and feeding second particulate material to the weighing system by means of the first feeder.

72. A method according to claim 71, including the control system ceasing feeding second particulate material to the weighing system in response to determining from signals received from the weighing system that a target mass of second particulate material is received by the weighing system.

73. A method according to any one of claims 68 to 72, wherein the feed system includes a second feeder, and feeding second particulate material to at least one mixing vessel by means of the second feeder.

74. A method according to claim 73, including the control system actuating the second feeder in response to the control system determining from the signals received from the weighing system that the target mass of second particulate material is received by the weighing system.

75. A method according to any one of claims 64 to 74, wherein the control system includes a user input device and memory.

76. A method according to claim 75, including a user specifying at least one of the following to create a batch of liquid: the quantity of the first particulate material to be delivered to the mixing vessel; the quantity of the second particulate material to be delivered to the mixing vessel and/or an additional mixing vessel; the quantity of water supplied to the or each mixing vessel; and the mixing time for the or each mixing device.

77. A method according to claim 75 or 76, including storing at least one formula for producing a batch of liquid in memory, the formula including values for at least some of the following parameters: the choice of particulate material; the quantity of water; the quantity of particulate material; the ratio of particulate material to water; the tolerance for the quantity of particulate material; and the mixing time.

78. A method according to any one of claims 64 to 77, wherein the control system includes a display device, and the display device displaying at least one of the following: the set quantity of the first particulate material to be delivered to the mixing vessel; the quantity of first particulate material already delivered; the current value of first particulate material from the weighing system; the set quantity of the second particulate material to be delivered to the mixing vessel and/or an additional mixing vessel; the quantity of second particulate material already delivered; the current value of second particulate material from the weighing system; the set quantity of water supplied to the or each mixing vessel; the quantity of water currently delivered to the or each mixing vessel; the set mixing time for the or each mixing device; and the mixing time elapsed since commencing the mixing process.

79. A method according to any one of claims 64 to 78, wherein the water supply means includes at least one flowmeter, and the control system controlling the quantity of water supplied to the or each mixing vessel according to signals received from the at least one flowmeter.

80. A method according to any one of claims 64 to 79, wherein the water supply means includes at least one valve, and the control system controlling operation of at least one valve according to signals received from the flowmeter.

81. A method according to any one of claims 64 to 80, wherein the or each mixing vessel includes a first sensor, and the control system actuating the mixing device in response to the first sensor detecting the presence of liquid in the mixing vessel.

82. A method according to any one of claims 64 to 81, including the control system supplying at least some water to the or each mixing vessel prior to delivering particulate material to the mixing vessel.

83. A method according to any one of claims 64 to 82, wherein the or each mixing device includes a mechanical agitator and a drive unit for driving the mechanical agitator.

84. A method according to any one of claims 64 to 83, wherein the control system includes a timer, and the control system operating the or each mixing device for a set period of time.

85. A method according to one of claims 64 to 84, including the control system actuating the or each mixing device prior to delivering particulate material to the mixing vessel.

86. A method according to any one of claims 64 to 85, wherein the or each mixing vessel includes a discharge valve; and the control system automatically opening the discharge valve at the end of the mixing process to discharge liquid from the or each mixing vessel.

87. A method according to any one of claims 64 to 86, including providing at least one storage vessel for storing liquid produced in at least one mixing vessel, wherein the or each storage vessel includes a liquid level sensor located towards its base.

88. A method according to claim 87, including the control system manufacturing a new batch of liquid in response to signals received from the liquid level sensor.

89. A method according to any one of claims 64 to 88, including providing at least one pump, and pumping liquid from the mixing vessel.

90. A method according to any one of claims 64 to 89, providing at least one pump and pumping liquid from the at least one storage vessel to pellet coating apparatus.

91. A method according to any one of claims 64 to 90, wherein at least one of the first feeders includes a vibration drive unit, and feeding particulate material to the weighing system by actuating the vibration drive unit.

92. A method according to any one of claims 64 to 91, wherein at least one of the second feeders includes a vibration drive unit, and feeding particulate material to the or each mixing vessel by actuating the vibration drive unit.

93. A method according to any one of claims 64 to 92, including providing a cleaning system arranged to clean at least one of: the mixing vessel and the storage vessel(s).

94. A method according to claim 93, including specify a period of time for which the cleaning system operates.

95. A method according to any one of the claims 64 to 94, including providing at least one intermediate storage vessel between the manufacturing apparatus and the pellet coating device, and storing the liquid enzyme in the intermediate storage vessel.

96. A method according to any one of the preceding claim 64 to 95, wherein the manufacturing apparatus is provided in the form of a standalone unit, and retro-fitting an existing pellet manufacturing system with the apparatus.

97. A method according to any one of the preceding claim 64 to 96, wherein the temperature of said first particulate material and, when present, of said second particulate material is kept below a predetermined temperature, in particular below a temperature which is not higher than 25°C.

98. A method according to any one of the preceding claim 64 to 97, wherein the relative humidity of the atmosphere surrounding said first particulate material and, when present, of said second particulate material, is kept below a predetermined relative humidity, in particular below a relative humidity which is not higher than 30%.