WO2018106180A1

WO2018106180A1 - Apparatus and method for producing aquaculture feed

Info

Publication number: WO2018106180A1
Application number: PCT/SG2016/050589
Authority: WO
Inventors: Luciaan Van Nieuwenhove
Original assignee: Pearl Aqua Co., Ltd.
Priority date: 2016-12-05
Filing date: 2016-12-05
Publication date: 2018-06-14
Also published as: TW201822643A; TWI837081B

Abstract

An apparatus (10) and a method (50) for producing an aquaculture feed (12) are provided. The apparatus (10) includes a divider (14) having a plurality of perforations (16) of a uniform size. The divider (14) is arranged to receive a feed paste (18) and to divide the feed paste (18) into a plurality of feed portions (20) to form a plurality of feed particles (22). A separator (24) is arranged to separate the feed particles (22) from the divider (14).

Description

APPARATUS AND METHOD FOR PRODUCING AQUACULTURE FEED

Field of the Invention

The present invention relates to aquaculture in general and more particularly to an apparatus and a method for producing an aquaculture feed. Background of the Invention

Aquaculture feeds of specific sizes are required at different growth stages of an aquatic organism. Very small aquatic organisms require feed particles of a very small size and the required size of the feed particles increases as the aquatic organisms grow. A drawback of conventional aquaculture feed production is difficulty in controlling the size of the feed particles produced. Consequently, feed particles with a wide size range are often produced using conventional aquaculture feed production methods.

Disadvantageously, when the feed particles are too large or too small for a specific growth stage of an aquatic organism, the inappropriately sized feed particles are not consumed by the aquatic organism and end up polluting the water and increasing the feed conversion ratio (FCR).

It is therefore desirable to provide an apparatus and method for producing an aquaculture feed of substantially uniform size. Summary of the Invention

Accordingly, in a first aspect, the present invention provides an apparatus for producing an aquaculture feed. The apparatus includes a divider having a plurality of perforations of a uniform size. The divider is arranged to receive a feed paste and to divide the feed paste into a plurality of feed portions to form a plurality of feed particles. A separator is arranged to separate the feed particles from the divider. In a second aspect, the present invention provides a method for producing an aquaculture feed. The method includes providing a feed paste and dividing the feed paste into a plurality of feed portions with a divider having a plurality of perforations of a uniform size. A plurality of feed particles is formed with the feed portions and the feed particles are separated from the divider.

Other aspects and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.

Brief Description of the Drawings Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic diagram of an apparatus for producing an aquaculture feed in accordance with an embodiment of the present invention;

FIG. 2 is a magnified image of one embodiment of a divider that may be used in the apparatus for producing an aquaculture feed illustrated in FIG. 1 ;

FIG. 3 is a schematic flow diagram illustrating a method for producing an aquaculture feed in accordance with an embodiment of the present invention;

FIG. 4 is a magnified image of aquaculture feeds of various sizes produced in accordance with embodiments of the present invention; and FIG. 5 is a further magnified image of one of the aquaculture feeds of FIG. 4.

Detailed Description of Exemplary Embodiments

The detailed description set forth below in connection with the appended drawings is intended as a description of presently preferred embodiments of the invention, and is not intended to represent the only forms in which the present invention may be practiced. It is to be understood that the same or equivalent functions may be accomplished by different embodiments that are intended to be encompassed within the scope of the invention.

Referring now to FIG. 1 , an apparatus 10 for producing an aquaculture feed 12 is shown. The apparatus 10 includes a divider 14 having a plurality of perforations or openings 16 of a uniform size. The divider 14 is arranged to receive a feed paste 18 and to divide the feed paste 18 into a plurality of feed portions 20 to form a plurality of feed particles 22. A separator 24 is arranged to separate the feed particles 22 from the divider 14.

The divider 14 may be a sieve, a net or other perforated material. The material from which the divider 14 is made retains the pre-formed feed particles 22 in the perforations 16 and subsequently releases the feed particles 22 from the perforations 16 in response to stimulation by the separator 24. Examples of suitable materials include, but are not limited to, nylon, polyester, acrylic and stainless steel.

Referring now to FIG. 2, one embodiment of the divider 14 is shown. In the embodiment shown, the divider 14 is a net made up of a plurality of plastic strings 25, the interwoven plastic strings 25 defining the perforations 16.

Referring again to FIG. 1 , being of a uniform size, the perforations 16 help to separate the feed paste 18 into individual feed portions 20 preformed to a desired size of the feed particles 22, the desired size of the feed particles 22 corresponding to the size of the perforations 16. In this manner, the size of the feed particles 22 in the aquaculture feed 12 may be controlled and the aquaculture feed 12 that is produced has uniformly sized feed particles 22 with a very narrow size distribution of within 10 micrometres (μιτι) of the desired size. Advantageously, this allows the feed particles 22 to be sized to suit specific growth stages of aquatic organisms simply by using a divider 14 having appropriately sized perforations 16. This flexibility in turn allows targeted delivery of the necessary nutrients at various stages of the life cycle of the aquatic organisms. The perforations 16 of the divider may have a size of between about 10 micrometres (μιη) and about 2000 μιη, producing feed particles 22 of corresponding sizes. In one embodiment, the perforations 16 of the divider 14 may have a size of between about 50 pm and about 800 Mm. In one particular embodiment, a divider 14 having perforations 16 of 150 pm may be used to produce feed particles 22 of a uniform size of 150 pm. In another embodiment, a divider 14 having perforations 16 of 50 pm may be used to produce feed particles 22 of a uniform size of 50 pm.

Further advantageously, the perforations 16 of the divider 14 help to shape the feed particles 22 as the feed portions 20 are retained in the perforations 16 whilst being dried and/or allowed to settle until the feed particles 22 are ready to be separated from the divider 14 without loss of shape.

In the present embodiment, the divider 14 comprises a conveyor 14 that is arranged to continually receive the feed paste 18 and to continually convey the feed particles 22 to the separator 24. Advantageously, this allows the production process to be run continuously and this increases the efficiency of the aquaculture feed production. In the embodiment shown, the conveyor 14 is in belt form. Nevertheless, it should be understood by those of ordinary skill in the art that the conveyor 14 is not limited to being implemented as a conveyor belt. In an alternative embodiment, the conveyor 14 may be a rotatable perforated disk.

In the embodiment shown, a spreader 26 is arranged to spread the feed paste 18 across the divider 14. The spreader 26 may be one or more scrapers that help spread the feed paste 8 evenly across the divider 14, reducing wastage and clumping of the subsequently formed feed particles 22. More particularly, the feed paste 18 may be pushed into the perforations 16 of the divider 14 by the one or more scrapers. In the embodiment shown, the scrapers provided on both sides of the divider 14 help ensure that the feed paste 18 is well set into the perforations 16 of the divider 14 and that excess feed paste 18 is removed and distributed to other unfilled perforations 16 of the divider 14. In the present embodiment, a dryer 28 is arranged to remove moisture from the feed particles 22. The dryer 28 may be a chamber dryer. In one embodiment, the feed particles 22 may be further dried to a required moisture content after separation from the divider 14. The further drying may take place in a fluidised bed dryer.

The separator 24 in the embodiment shown comprises one or more first nozzles 24 arranged to direct a pressurised flow of a first fluid 30 at the divider 14 to dislodge the feed particles 22 from the divider 14. In one embodiment, the first fluid 30 may be a gas such as, for example, air. In such an embodiment, the feed particles 22 are forced out of the perforations 16 of the divider 14 by gas pressure. In an alternative embodiment, the feed particles 22 may be separated from the divider 14 by other means such as, for example, ultrasonic vibration or mechanical separation. An example of a mechanical separation technique that may be employed involves pushing the feed particles 22 out from the perforations 16 of the divider 14 with, for example, a rubber roller or other suitable device.

In the present embodiment, a cleaner 32 is arranged to remove waste 34 from the divider 14. In the embodiment shown, the cleaner 32 comprises one or more second nozzles 32 arranged to direct a pressurised flow of a second fluid 36 at the divider 14 to dislodge the waste 34 from the divider 14. In one embodiment, the second fluid 36 may be a gas such as, for example, air or a liquid such as, for example, water. In such an embodiment, leftover portions of the feed paste 18 are cleared from the divider 14 by gas pressure or liquid pressure, respectively, allowing the production process to re-start with a clean divider 14 that receives fresh feed paste 18. This helps ensure that the quality of the aquaculture feed 12 produced is not compromised. Furthermore, in an embodiment where the second fluid 36 is a liquid, one or more additional gas nozzles may be provided after the one or more second nozzles 32 to dry the divider 14 before re-starting the production process.

Referring now to FIG. 3, a method 50 for producing the aquaculture feed 12 will now be described. The method 50 begins at step 52 by providing a feed paste 18. The feed paste 18 may include ingredients typical of an aquaculture feed formula. The aquaculture feed formula may be prepared into a paste form by mixing together individual ingredients of the aquaculture feed formula and then transforming the mixture into a paste by adding water and optionally a binder to increase the binding capacity of the feed particles 22 to prevent water soluble components of the aquaculture feed 12 leaching out into the water when fed to aquatic organisms.

To increase nutritional value, medicinal value and/or acceptance levels of the aquaculture feed 12, the feed paste 18 may also include, for example, classic feed ingredients such as larval fish or shrimp formula, a nutritional supplement such as vitamins, minerals, docosahexaenoic acid (DHA) and/or eicosapentaenoic acid (EPA), a probiotic, a vaccine, a medicine such as an antibiotic or combinations thereof. Examples of suitable probiotics include, but are not limited to, Bacillus subtilis, Bacillus licheniformis, Bacillus amyloliquefaciens, Paenibacillus macerans, Lactobacillus acidophilis and Saccharomyces cerevisiae. Examples of suitable vaccines include, but are not limited to, a vibriosis vaccine and a furunculosis vaccine.

To produce feed particles 22 with high oil content, the feed paste 18 may include up to about 30 mass% of a lipid supplement. The lipid supplement may be an emulsion of highly unsaturated fatty acids (HUFA) containing high levels of omega-3 fatty acids, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Advantageously, the lipid supplement provides a nutritional lipid boost and the high oil content also results in a neutrally buoyant particle that is more readily consumed by aquatic organisms. Such formulations with high oil inclusions may be used to replace conventional enriched live foods that are difficult to produce and that may be of the wrong size. The enriched feed particles may be directly fed to shrimp or fish larvae in combination with rotifers or Artemia.

At step 54, the feed paste 18 is divided into a plurality of feed portions 20 with a divider 14 having a plurality of perforations 16 of a uniform size. More particularly, the feed paste 18 is received in the uniformly-sized perforations 16 of the divider 14 and is thus separated into uniform feed portions 20 by the divider 14. Individual uniformly-sized feed particles 22 are thus preformed in the perforations 16 of the divider 14. In one embodiment, the perforations 16 of the divider 14 may have a size of between about 10 pm and about 2000 pm and the feed particles 22 that are formed are correspondingly sized.

In the present embodiment, the feed paste 18 is spread across the divider 14 at step 56. This helps ensure that the perforations 16 of the divider 14 are completely and evenly filled with the feed paste 18. At step 58, a plurality of feed particles 22 is formed with the feed portions 20.

The feed particles 22 are formed when the feed portions 20 are sufficiently dried.

In the present embodiment, moisture is removed from the feed particles 22 at step 60. The feed particles 22 may be dried before separation from the divider 14 or after separation. Drying to the desired moisture content of between about 4% and about 10% moisture may be performed by leaving the feed portions 20 in the perforations 16 of the divider 14 in a drying chamber. In an alternative embodiment, the feed particles 22 may first be partially dried before being separated from the divider 14 and then further dried on a belt or fluidized bed dryer. Advantageously, this allows the feed particles 22 to be dried at low temperatures as the drying time and temperature in both cases (whilst on the divider 14 or after separation from the divider 14) may be controlled. Drying at low temperatures is known to better preserve the nutritional value and the survival of heat sensitive ingredients such as vitamins.

At step 62, the feed particles 22 are separated from the divider 14. This may be by directing a pressurised flow of a first fluid 30 at the divider 14 to dislodge the feed particles 22 from the divider 14. The first fluid 30 may be a gas such as, for example, air. In an alternative embodiment, the feed particles 22 may be separated from the divider 14 by other means such as, for example, ultrasonic vibration or mechanical separation.

In the present embodiment, waste 34 is removed from the divider 14 at step 64. This may be by directing a pressurised flow of a second fluid at the divider 14 to dislodge the waste 34 from the divider 14. The second fluid 36 may be a gas such as, for example, air or a liquid such as, for example, water. In an embodiment where the second fluid 36 is a liquid, the divider 14 may be dried before re-starting the production process.

In the present embodiment, the feed paste 22 may be continually provided to the divider 14 and the feed particles 22 that are formed may be continually conveyed to the separator 24 in a continues process via, for example, a conveyor belt system.

Referring now to FIG. 4, a magnified image of aquaculture feeds 12 of various sizes produced in accordance with embodiments of the present invention is shown. In FIG. 4, the feed particles 22 of the aquaculture feed 12 in the upper left quadrant have a size of 25 pm, the feed particles 22 in the upper right quadrant have a size of 55 pm, the feed particles 22 in the lower right quadrant have a size of 150 pm, and the feed particles 22 in the lower left quadrant have a size of 250 pm.

Referring now to FIG. 5, a further magnified image of one of the aquaculture feeds 12 of FIG. 4 is shown. As can be seen from FIG. 5, the aquaculture feed 12 includes a plurality of uniformly sized feed particles 22. In the present embodiment, the feed particles 22 have a size of 150 pm.

As is evident from the foregoing discussion, the present invention provides an apparatus and a method for producing an aquaculture feed of substantially uniform feed particle size. Advantageously, a uniform feed particle size makes it easier to target specific growth stages of an aquatic organism to be fed. In contrast, if the feed particles have a wide size range, a portion of the aquaculture feed will be too large or too small for consumption and the unconsumed feed portion ends up polluting the water in the rearing tanks. Further advantageously, the size of the feed particles may also be controlled to produce specifically sized feed particles for targeted delivery to aquatic organisms at various growth stages. The present invention allows production of one specific size of feed particles without loss of fines or unwanted sizes. With the present invention, very small feed particles may be produced without risk of obstructing the whole system as the feed particles that are not separated from the divider are cleaned out by a counter jet of air or water without blocking the whole system. The present invention is also operable with a feed paste having a high dry weight content and this translates into a high output. The aquaculture feed that is produced by the present invention may provide soft feed particles for larval shrimp, larval fish and/or other aquatic organisms and may serve as a partial or complete Artemia Nauplii, rotifer, other zooplankton or algae replacement or substitute and/or as a carrier for other feed ingredients or feed supplements such as, for example, specific nutrients, vitamins, oils, pro-biotics, vaccines, medicines, heat sensitive ingredients, water soluble ingredients and classic feed ingredients. The aquaculture feed that is produced by the present invention may also be used to replace conventional dry feeds.

While preferred embodiments of the invention have been illustrated and described, it will be clear that the invention is not limited to the described embodiments only. Numerous modifications, changes, variations, substitutions and equivalents will be apparent to those skilled in the art without departing from the scope of the invention as described in the claims.

Further, unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising" and the like are to be construed in an inclusive as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to".

Claims

1 . An apparatus for producing an aquaculture feed, comprising:

a divider having a plurality of perforations of a uniform size, wherein the divider is arranged to receive a feed paste and to divide the feed paste into a plurality of feed portions to form a plurality of feed particles; and

a separator arranged to separate the feed particles from the divider.

2. The apparatus of claim 1 , wherein the divider comprises a conveyor that is arranged to continually receive the feed paste and to continually convey the feed particles to the separator.

3. The apparatus of claim 1 , wherein the perforations of the divider have a size of between about 10 micrometres (pm) and about 2000 pm.

4. The apparatus of claim 1 , further comprising a spreader arranged to spread the feed paste across the divider.

5. The apparatus of claim 1 , further comprising a dryer arranged to remove moisture from the feed particles.

6. The apparatus of claim 5, wherein the dryer is a chamber dryer.

7. The apparatus of claim 1 , wherein the separator comprises one or more first nozzles arranged to direct a pressurised flow of a first fluid at the divider to dislodge the feed particles from the divider.

8. The apparatus of claim 1 , further comprising a cleaner arranged to remove waste from the divider.

9. The apparatus of claim 8, wherein the cleaner comprises one or more second nozzles arranged to direct a pressurised flow of a second fluid at the divider to dislodge the waste from the divider.

10. A method for producing an aquaculture feed, comprising:

providing a feed paste;

dividing the feed paste into a plurality of feed portions with a divider having a plurality of perforations of a uniform size;

forming a plurality of feed particles with the feed portions; and

separating the feed particles from the divider.

11. The method of claim 10, wherein the feed paste is continually provided to the divider and the feed particles that are formed are continually conveyed to the separator.

12. The method of claim 10, wherein the perforations of the divider have a size of between about 10 micrometres (μιη) and about 2000 pm.

13. The method of claim 10, further comprising spreading the feed paste across the divider.

14. The method of claim 0, further comprising removing moisture from the feed particles.

15. The method of claim 10, wherein the step of separating the feed particles from the divider comprises directing a pressurised flow of a first fluid at the divider to dislodge the feed particles from the divider.

16. The method of claim 10, further comprising removing waste from the divider.

17. The method of claim 16, wherein the step of removing waste from the divider comprises directing a pressurised flow of a second fluid at the divider to dislodge the waste from the divider.