DE1294352B - Device for treating substances in powder form or as granules - Google Patents

Description

The invention relates to a device for treating in powder form or substances present as granules with a liquid.

The purpose of such a treatment may differ in each case be. In the case of a product, freedom from dust is required, in the case of product B a good solubility in water or other liquids, with product C a mixture a liquid fragrance, and finally a certain granulate size can be requested will. Often two or more demands are made at the same time.

In the known devices for treating in powder form or As a rule, substances present as granules are devices for carrying out special procedures of chemical or physical processes between gaseous or liquid substances and solid granular material, e.g. B. to Manufacture of dry milk products.

The introduction of the dry matter and its distribution as well as the distribution of the liquid substances takes place in each different way. A distribution of the Liquids in fluidized beds are carried out in a known manner by spraying on and finely distributing them the liquid on the surface of the bubbling fluidized bed or through Distribution pipes, which through side openings in the wall of the treatment chamber are introduced and extendable.

A process with process steps has also become known an auxiliary gas dust mixture is blown into a swirl chamber, the liquid or the molten auxiliaries are sprayed in, whereby they are passed through the auxiliary gas stream be made to solidify or dry out and possibly an evaporation of the auxiliary liquid by influencing the temperature beforehand or afterwards the dust mixture can take place.

Finally, there is an apparatus for making a dry milk product became known, in which the dry matter by means of air in a treatment chamber is blown in, with the finely divided liquid entering the delivery jet is sprayed into the treatment chamber.

It has been found through experiments that an improvement in the distribution of liquids in the dry matter leads, among other things, to an improvement in the end product. These Improvement consists in a more even granulation of the products, thus one better visibility.

For better distribution of the liquid in a moving solid gas mixture a device is used to spray liquids into powdery substances or on granules, consisting of a tower with feeding devices of liquid in finely divided form and with a arranged in its upper part, solid feed connected to a pneumatic conveying line, as well as a Outlet for the sprayed solids in the lower, cone-shaped tower end, this contains openings for drawing in gas through one in the upper part of the tower suction line connected tangentially and equipped with control elements, characterized in that in the lower third of the tower immediately above the conical At the end of the circumference, several rows of holes are attached in a ring one above the other are, in front of which spray cans are arranged at a distance, each over a common Ring line with remotely controlled locking elements in the supply and discharge line connected are.

This device can also be designed so that the individual Ring lines to different storage tanks for different liquids are connected.

Finally, there is another embodiment of this device in that the pneumatic conveying line for supplying the powdery substances is connected to a solids feeder containing a bulk weigher, which is followed by a funnel with a lower glass cylinder, which is inserted into a Infinitely adjustable sluice opens, to which a screw conveyor is connected is.

The division of the tower into a vortex zone in the lower conical Part of the tower and in a calming zone in the cylindrical upper part by extension of the material separator outlet to over the middle of the tower down to immediately in the spray area of the liquid substances leads to a relief of the downstream Dedusting devices, which is important when spraying sticky liquids is.

In the treatment of sensitive substances it has been shown that for To stabilize the agglomerates, it is advisable to place the device over a drying tower to be arranged in such a way that the treated material from the treatment chamber immediately falls into the drying tower, so that mechanical lines also during the drying process Stressing of the granules formed takes place. The treated particles leave thus the treatment room through the drying tower is always floating, slowly sinking Condition and are gently dried, stabilized and can be placed underneath the dryer bagged or packaged directly.

It has also been shown that the similarity and the uniformity the structure of the granulate also depends on how the original product is mixed became. Experiments have shown that an air mixer, e.g. B. Patent No. 1 152 877, mixed goods more favorable results with regard to the uniformity of the granulate structure shows as a good mixed on a mechanical mixer of any kind.

The essence of the device according to the invention is now based on a drawing shown.

F i g. 1 shows a schematic representation of the operation of the Procedure; Fig. 2 shows a section A-1R through the spray chamber with the ring-shaped Arrangement of the nozzles on the treatment tank; Fig. 3 shows a section through an injection opening with nozzle, supply line, manual valve and ring line; F i g. 4 shows the regulating flap in detail, Fig. 5 shows the impeller with the injector flap.

F i g. 1 shows a working diagram of the device, with the actual An air mixer is connected upstream of the spraying process.

In the air mixer 1, FIG. 1, the individual components are by means of Air mixed for a mixing time of 10 to 20 seconds. Mechanical mixing requires a time investment of 10 to 20 minutes, leads to sensitive products due to the mechanical stress to a change in the flow properties of some components, so that the even feed to the dosing elements is affected.

Mixing takes place in batches that are fed to the secondary container 2 will. The product flows into the post-hopper via a coarse metering lock 3 a bulk weigher 4 with a small bulk volume in the hopper S. An existing time relay the balance triggers the tilting of the balance after the set time. In the same time period the material in the hopper 5 is fed via a continuously variable rotary valve 6, a screw conveyor 7 in the centrifugal wheel 8 to the pneumatic conveyor line 9 and conveyed via the separator 10 into the lower zone of the spray container 11.

A slight negative pressure is maintained in the tower 11 by the fan 32. The conveying air flows through the fan 12 and the return line 13 to the steering wheel in a continuous cycle. The individual beds can run out in the glass cylinder 14 observed and by changing the speed of the rotary feeder 6 by means of stepless Drive can be adjusted so that the material in the time period up to the next The bulk has just been removed. This makes it a very precise dosage of the dry matter possible because the weight accuracy from bulk to bulk, z. B. at 5 kg, is determined by the scales and the distribution of these 5 kg, z. B. to 14 seconds pouring period, from the rotary valve and the downstream Snail will take over. Another check is on the glass cylinder or sight glass 15 possible. Any material gaps can be corrected by readjusting the stepless Gearbox to be balanced. The centrifugal wheel 8 has the task of the material to accelerate the conveying speed, to avoid a pulsating conveying movement and with the aid of the injector 41, FIG. 5, a pressure reduction below the rotary valve to undertake. These measures are also to ensure a trouble-free flow Powdered substances of various properties are required by the rotary valve.

The negative pressure generated in the tower 11 by the low-pressure fan, the height of which can be changed by regulating flaps 16 and 16a, Fig. 4, causes air to flow in through the treatment chamber at outlet 17 falling product. As a result, the material is thrown up in a kind of central fountain, forms a cloud into which the spray nozzles 18, which are arranged in the form of a ring, now pass through the openings 19, FIG. 2, spray the liquid in finely divided form.

This type of spraying prevents the sprayed material from settling on the casing of the treatment chamber and enables maximum surface contact and even distribution of the liquid in the dry matter.

As usual, the liquid is supplied via a metering piston pump 29 including the necessary safety fittings to the Main locking members 24 out. A pressure filter is connected downstream of the closing members 24 23. The liquid reaches the distribution ring 22 from this pressure filter the individual nozzle assemblies 20, FIG. 3, which can be closed by a manual valve 21 each are. Opposite to the inlet connection is the output connection, the over an 1800 arc goes up at a height that is less than the height of the individual nozzle assemblies from the ring line to the nozzle 18.

Via a further closing element 25 and a lateral discharge the line can be emptied with a closing element 26.

Both closing elements 24 and 25 are remotely controlled by a control element each. The closing member 26 is operated by hand and is used to inject the amount to drain, under the required nozzle pressure.

From the funnel 27, the liquid is returned to a container or back led to the container 30. The container 30 is normally not shown Liquid treatment plant charged.

These tanks are equipped with level indicators, temperature controls and equipped with automatic control. The line leads via the closing element 31 to the suction side of the dosing pump.

To maintain and set an optimal degree of separation and for the purpose of coordinating the dust transport via fan 34, separator 33 back to the treatment tower 11 there is a regulating flap in the suction line in front of the blower 33 built-in, consisting of a pivoting flap 16 and a Schicber 16 a, Fig.4. When the flap is closed, the air flow in the tower is throttled. The cross section above the flap for sucking in fresh air is enlarged. This cross section can be regulated by an additional slide 16a so that the separator 33 have an optimal degree of separation.

The adverse effects of pulsating currents occurring in the tower on the separator vortices are avoided by having one on both separators Partial air volume is sucked off with the dust and via a separate high pressure fan 34 and the connecting line 36 tangentially into the tower in the same direction as the Flow is injected. Each separator is separated by one Line, sucked off, and the union of both lines takes place immediately before the fan suction nozzle 34. There are several openings on the inside of both suction elbows 35 provided, which are covered by rubber sleeves 37 and only in the event that a blockage occurs.

The exhaust air from the separator is fed into a pressure filter 38 with a collecting funnel, The outlet nozzle 39 is guided into the sack 40.

The following two examples show the production of a milk replacer with 17 ° ío and a fat-fat skimmed milk concentrate up to 55%.

Example 1 The components of 300/0 spray skimmed milk, 30 °! o rolled skimmed milk, 100, o sugar or pregelatinized starch, 10 to 15 per cent. whey powder and 10/0 vitamins mixed in the air mixer and after mixing in the container 2 drained.

While the components are mixed in batches, takes place spraying fat continuously. The mixed comes from the container 2 Milk powder via the rotary valve 3 into the scale 4 and is here via the device 14, 6, 7, 8, 9 and 10 continuously and in a steady stream with a certain performance dem Tower 11 fed. After a set The fat turns on automatically after about 10 to 40 seconds, i.e. H., the corresponding locking devices open. The finished product falls at the outlet of the funnel 17 and is bagged.

Example 2 Example 2 shows the production of a concentrate with 55 ovo fat described. Instead of the components, only spray skimmed milk is used here or rolled skimmed milk is used and fed to the container 2 without mixing. Of the The process is the same as in Example 1, with the difference that the 17 of air entering outside is cooled by a cooling unit. The amount of heat to be dissipated when cooling corresponds roughly to the heat of solidification of the fat. Also influenced the amount of cooling the fineness of the resulting end product.

Example 3 In a manner similar to skimmed milk powder concentrate powdered substances are also treated to increase solubility, e.g. B. at the The components, consisting of 73.50 / 0 powdered sugar, 25% starch, 1.5% flavors, homogeneously with one another by means of an air mixer mixed, then sprayed with lOO / o water, which is caused by the spray treatment in the tower (in a similar way to example 2), and then the Product dried down to 501o by means of a cooling drying tower arranged under the tower. The product produced in this way shows a uniform granular structure, loose structure (porous), is very hygroscopic and dissolves quickly in water or milk.

Example 4 In the production of easily soluble cereal flours the procedure is the same as for the production of cocoa drink after Example 3, with the difference that the flour is initially on a Fineness of 50 p is brought, then exposed to the spraying process with the addition of 10% water in order to finally return to normal humidity in the subsequent flotation dryer to be dried down by 14010.

Claims (3)

Claims: 1. Device for spraying liquids in powdery substances or on granules, consisting of a tower with facilities for the supply of liquid in finely divided form and with one in its solids feeder arranged on the upper part and connected to a pneumatic conveying line, and an outlet for the sprayed solids in the lower cone-shaped Tower end, which contains openings for the suction of gas through one in the upper part of the Tower connected and equipped with control elements suction line, thereby characterized in that in the lower third of the tower immediately above the conical At the end of the circumference, several rows of bores (19) are attached in a ring one above the other are, in front of which spray nozzles are arranged at a distance, which each have a common Ring line (22) with remote-controlled closing elements (24, 25) in the supply and discharge are connected. 2. Apparatus according to claim 1, characterized in that the individual Ring lines (22) on different storage containers (30) for different Liquids are connected. 3. Apparatus according to claim 1 and 2, characterized in that the pneumatic conveying line (9) with a bulk weigher (4) containing solids supply device (3) connected to a funnel (5) with a lower glass cylinder (14) connects, which opens into a continuously adjustable lock (6), to the one Conveyor screw (7) is connected.