WO2023108180A1

WO2023108180A1 - Ventilation system and apparatus for rearing insects

Info

Publication number: WO2023108180A1
Application number: PCT/ZA2022/050064
Authority: WO
Inventors: Barendes Anton GRESSE
Original assignee: Stellenbosch University
Priority date: 2021-12-07
Filing date: 2022-12-01
Publication date: 2023-06-15
Also published as: ZA202110059B

Abstract

An apparatus (30), process and ventilation system (1) are provided for insect rearing. At least one cluster (2) of one or more stacks of crates (4) are provided to contain immature phases of insects. Each cluster is provided with a ventilation system including air-permeable curtains (12) that form an enclosure (6) around the cluster. A top opening (8) is provided which cooperates with a fan (10) for sucking air out. The process includes the steps of placing immature phases of insects and feed into crates (4). The crates are stacked onto trolleys (18) and arranged into a cluster beneath a fan (10). An enclosure (6) is formed around the cluster (2) with air-permeable curtains (12), the enclosure (6) having a top opening (8) which cooperates with the fan (10). The enclosure (6) is ventilated by operating the fan (10) to suck air out of the enclosure.

Description

VENTILATION SYSTEM AND APPARATUS FOR REARING INSECTS

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from South African patent application number 2021/10059 filed on 7 December 2021 , which is incorporated by reference herein.

FIELD OF THE INVENTION

This invention relates to a ventilation system for an insect rearing apparatus.

BACKGROUND TO THE INVENTION

In recent years, a focus has been placed on the effects of protein production on the environment and more environmentally friendly methods of producing protein have been researched. Insects have been proposed as an alternative protein source to traditional protein farming, such as cattle, sheep, chickens, and pigs. Insects with a larval and/or maggot phase are especially suited for insect farming. These insects generally have four life phases, namely: egg/embryo, larva, pupa, and adult. It is common for insects to be harvested during the end of the second stage, when the insect has reached the stage of mature larvae just before turning into a pupa.

Breeding and rearing insects require specific environmental conditions to be maintained during the different life phases. It is especially important to maintain the correct temperature, humidity, and airflow for the larvae to grow optimally. Therefore, it has become common practice at insect rearing facilities to use energy-intensive HVAC (heating, ventilation, and air conditioning) systems to ensure the correct environmental conditions are maintained. The downside to this, is that these HVAC systems are expensive and use a lot of electricity which increases production cost and makes the system less environmentally friendly. These HVAC systems may also have a large footprint within the production facility which further increases production costs as it reduces the amount of space available for insect breeding and rearing. Should such an HVAC system run into technical problems, there is a high likelihood that the whole production line for breeding and rearing the insects will have to be stopped while the problem is fixed.

The invention aims to address these shortcomings, at least to some extent.

The preceding discussion of the background to the invention is intended only to facilitate an understanding of the present invention. It should be appreciated that the discussion is not an acknowledgment or admission that any of the material referred to was part of the common general knowledge in the art as at the priority date of the application.

SUMMARY OF THE INVENTION

In accordance with an aspect of the invention there is provided a ventilation system for an insect rearing apparatus, the insect rearing apparatus having at least one cluster of one or more stacks of crates adapted to contain immature phases of insects, the ventilation system including: one or more at least partially air-permeable curtains that together form an enclosure around the cluster; and a top opening in the enclosure which cooperates with a fan for sucking air out of the enclosure so as to reduce air pressure within the enclosure.

The one or more at least partially air-permeable curtains may be divided into a main section and a bottom skirt with the bottom skirt blocking airflow and with the main section being air-permeable.

The main section of the one or more at least partially air-permeable curtains may have a height equal to a space between a top of a bottom crate and a top of a top crate in the stack of crates.

The ventilation system may have a top cover for the enclosure which blocks airflow and has a hole which cooperates with the fan. The top cover may be made of polyvinyl chloride sheeting.

The one or more at least partially air-permeable curtains may be weighted at the bottom to restrict airflow at a base of the enclosure.

The enclosure may be made up of four at least partially air-permeable curtains that are connected at their corners or along free edges at which they meet with attachment means. The attachment means may be hook and loop fasteners.

The bottom skirt of the curtains may be made of polyvinyl chloride sheeting.

The main section of the curtains may be made of shade netting. The shade netting may have a shade percentage of between 40 and 60%.

In accordance with another aspect of the invention there is provided an apparatus for rearing insects comprising clusters of one or more stacks of crates adapted to contain immature phases of insects, wherein each cluster is provided with a ventilation system and wherein the ventilation system includes: one or more at least partially air-permeable curtains that together form an enclosure around the cluster; and a top opening in the enclosure which cooperates with a fan for sucking air out of the enclosure so as to reduce air pressure within the enclosure.

A cluster may be made up of two rows of four stacks of crates. The rows may be spaced between 140 and 160 mm apart from each other. The four stacks may be spaced between 35 and 55 mm apart from each other.

The crates may be stacked on trolleys. Each trolley may have a pin that slots into a corresponding guiding rail located on a floor over which the trolley moves.

The fan may be provided in an extraction aperture in a roof of a building in which the clusters are located.

The one or more at least partially air-permeable curtains that form the enclosure may be as described above.

In accordance with another aspect of the invention there is provided a process of rearing insects comprising: placing immature phases of insects and feed into crates and stacking the crates onto trolleys; arranging the trolleys into a cluster beneath a fan; forming an enclosure around the cluster with one or more at least partially air-permeable curtains, the enclosure having a top opening which cooperates with the fan; and ventilating the enclosure by operating the fan so as to suck air out of the enclosure.

The insects may be black soldier fly larvae.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings: Figure 1 is a sectional side view of an embodiment of a ventilation system with a cluster of crates therein;

Figure 2 is a three-dimensional view of the embodiment of the ventilation system of Figure 1 ;

Figure 3 is a three-dimensional view of the embodiment of the cluster of stacks of crates of Figure 1 ;

Figure 4 is a front view of the cluster of Figure 3;

Figure 5 is a side view of the cluster of Figure 3;

Figure 6 is a three-dimensional view of a trolley without crates;

Figure 7 is a three-dimensional view of a trolley with crates;

Figure 8 is a three-dimensional view of an apparatus for rearing insects; and

Figure 9 is a flow diagram of the process of rearing insects.

DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS

An apparatus and ventilation system are provided for insect rearing. The insect rearing apparatus has at least one cluster of one or more stacks of crates adapted to contain immature phases of insects. Each cluster is provided with a ventilation system. The ventilation system includes one or more at least partially air-permeable curtains that together form an enclosure around the cluster. A top opening is provided in the enclosure which cooperates with a fan for sucking air out of the enclosure so as to reduce air pressure within the enclosure. Further, a process of rearing insects is provided. The process includes the steps of placing immature phases of insects and feed into crates. The crates are then stacked onto trolleys and arranged into a cluster beneath a fan. An enclosure is formed around the cluster with one or more at least partially air-permeable curtains, the enclosure having a top opening which cooperates with the fan. Finally, the enclosure is ventilated by operating the fan so as to suck air out of the enclosure.

Figures 1 and 2 show different views of a ventilation system (1 ) for a cluster (2) of stacks of trays or crates (4) according to an embodiment of the invention. The illustrated ventilation system (1 ) includes partially air-permeable curtains that form an enclosure (6) around the cluster (2) of stacks of crates (4). A top opening (8) is provided in the enclosure (6) which cooperates with a fan (10) for sucking air out of the enclosure (6) to reduce air pressure within the enclosure (6).

As indicated by the arrows in Figure 1 , the fan (10) facilitates the movement of air within the enclosure (6) whereby ambient air is pulled in through the partially air-permeable curtains (12), moves horizontally over the stacked crates (4), and then gets sucked up by the fan (10). The air flows in a laminar fashion over the crates before being sucked up by the fan. In use, the crates contain immature phases of insects such as black soldier fly larvae that produce metabolic heat while growing. A substrate for the insects to feed on is also provided in the crates. The hot air emanating from the crates mixes with the ambient air that is pulled in through the curtains and the mixture of air is ventilated out by the fan. The speed at which the fan operates may be adjusted according to a need to maintain the substrate temperature at or below a set threshold, for example on warmer days it may be necessary for the fan to operate at a higher speed. The size and strength of the fan will be determined by the size of the cluster and the number of crates housed within each enclosure. For the configuration depicted in Figure 2, the desired environmental conditions can be maintained, depending on ambient conditions as well as the age and heat production of the larvae, with a fan capacity that can be adjusted between 0,2 and 1 cubic meter of air displacement per second.

In addition to air being ventilated out of the enclosure by the extraction fan, moisture is also removed thereby regulating the humidity within the enclosure. In temperate climates, the removal of moisture from the enclosure greatly reduces the chances of the air within the enclosure reaching its saturation point.

In the embodiment shown in Figures 1 and 2, the enclosure (6) may be made up of four at least partially air-permeable curtains (12) that are connected at their corners or along the sides at which they meet with attachment means. Any suitable attachment means may be used such as hook and loop fasteners.

The one or more partially air-permeable curtains (12) may be divided into two parts. A main section (12a) may be air-permeable while a bottom skirt (12b) may block airflow. By blocking airflow at the bottom skirt (12b) air is allowed to flow horizontally over the crates (4) before being sucked up by the fan (10) at the top. The bottom skirt (12b) may be made from a material that blocks airflow, such as polyvinyl chloride sheeting. The main section (12a) may be made from air permeable material, such as shade netting. The shade netting may have a shade percentage of between 40 and 60%, such as about 50%.

The main section (12a) may have a height equal to a space between a top of a bottom crate and a top of a top crate. Accordingly, the bottom skirt (12b) may have a height equal to the space between the bottom of the bottom crate and the floor. By blocking airflow at the bottom skirt of the curtain, air cannot be pulled in through the curtain from below the crates. As explained above, the air should be pulled in through the curtains and move horizontally over the crates to mix with the heated air produced by the metabolic activity of the insects. Once this is achieved, the heated air gets pulled up by the fan ensuring the enclosure is well ventilated.

To further restrict airflow at the base of the enclosure (6) the one or more at least partially air- permeable curtains (12) may be weighted at the bottom. This may be achieved by attaching a PVC pipe (14) filled with a heavy substance, such as cement, at the bottom of each curtain (12). The top cover (16) of the enclosure (6) may also be configured to block airflow thereby restricting air from entering the enclosure (6) from above to optimise horizontal airflow across the crates (4). Any suitable material, such as polyvinyl chloride, may be used for the top cover. The top cover (16) has a hole which cooperates with the fan.

A roof (17) of the enclosure includes a top opening (8) for the fan (10). The roof (17) may further include a frame (15) that the one or more curtains can be attached to and suspended from. The enclosure may be suspended from the roof of a building with cables connected to the frame. In another embodiment, pillars may be used to support the enclosure. The pillars may be connected to the frame of the roof of the enclosure.

As shown in Figure 3, a cluster (2) may be made up of two rows of four stacks of crates (4), each stack having eight crates stacked vertically, although different configurations are obviously possible. The rows may be spaced slightly apart so as to enable adequate airflow, such as between 140 and 160 mm apart from each other. The four stacks may also be spaced slightly apart, for example between 35 and 55 mm apart.

In the embodiment illustrated in Figures 3 to 7 the crates (4) are stacked on trolleys (18). The trolleys (18) have wheels (20) and there may be a guiding pin (22) that slots into a corresponding guiding rail (24) as shown in Figures 4 and 5 so as to maintain required stack spacing. The pin (22) and rail (24) assist in aligning the trolleys within the cluster (2). Any suitable material may be used to construct the frames of the trolleys such as stainless steel. The frames are designed to support crates that are adapted to contain immature phases of insects (such as larvae) for rearing. Any suitable material may be used to make the crates, such as plastic. Figure 8 illustrates an embodiment of an apparatus (30) or facility for rearing insects. The apparatus (30) comprises clusters (2) of one or more stacks of crates (4) adapted to contain immature phases of insects such as black soldier fly larvae. Each cluster (2) is provided with a ventilation system which includes one or more partially air-permeable curtains (12) that together form an enclosure around the cluster (2). A top opening in the enclosure cooperates with a fan (10) that sucks out the air in the enclosure to reduce the air pressure within the enclosure. In this illustration, six clusters (2) are shown, but the apparatus may include any number of such clusters.

The fan (10) may be provided in an extraction aperture in a roof of a building in which the clusters (2) are located. For a cluster made up of 8 stacks of standard sized crates for black soldier fly larvae, each stack supporting 8 crates, the applicant has found that a variable speed fan capable of ventilating between 0.2 - 1 cubic meters/second of air to be sufficient for most environmental conditions.

As illustrated in Figure 9, a process of rearing insects according to the invention comprises placing (100) immature phases of insects and feed into crates. The crates are then stacked (102) onto trolleys and arranged (104) into a cluster beneath a fan. An enclosure is formed (106) around the cluster with one or more at least partially air-permeable curtains, the enclosure having a top opening which cooperates with the fan. Finally, the enclosure is ventilated (108) by operating the fan so as to suck air out of the enclosure. In one embodiment the immature phases of insects may be black soldier fly larvae.

The larvae produce metabolic heat as they feed and grow. The ventilation fan sucks out the heated air and moisture produced by the growing larvae thereby reducing the air pressure within the enclosure. Ambient air is consequently pulled in through the curtains due to the reduced air pressure within the enclosure. The ambient air moves horizontally over the top of the crates and mixes with the hot air produced by the metabolic activity of the larvae inside the crates. The hot air rises and is sucked up by the fan and removed from the enclosure thereby ensuring that the enclosure is well ventilated and at optimal conditions for rearing the insects.

Using the described apparatus, the applicant has found that cooling equipment like HVAC systems are not required, and adequate heat and moisture extraction can be obtained with just the mechanical ventilation using the fans as described, and least in moderate climatic environments. This results in an appreciable cost saving in comparison with systems that require HVAC. The foregoing description has been presented for the purpose of illustration; it is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Persons skilled in the relevant art can appreciate that many modifications and variations are possible in light of the above disclosure.

The language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based hereon. Accordingly, the disclosure of the embodiments of the invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.

Finally, throughout the specification and accompanying claims, unless the context requires otherwise, the word ‘comprise’ or variations such as ‘comprises’ or ‘comprising’ will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Claims

CLAIMS:

1 . A ventilation system (1 ) for an insect rearing apparatus (30), the insect rearing apparatus (30) having at least one cluster (2) of one or more stacks of crates (4) adapted to contain immature phases of insects, the ventilation system (1 ) including: one or more at least partially air-permeable curtains (12) that together form an enclosure (6) around the cluster (2); and a top opening (8) in the enclosure (6) which cooperates with a fan (10) for sucking air out of the enclosure (6) so as to reduce air pressure within the enclosure.

2. The ventilation system (1 ) as claimed in claim 1 , wherein the one or more at least partially air-permeable curtains (12) are divided into a main section (12a) and a bottom skirt (12b) with the bottom skirt (12b) blocking airflow and with the main section (12a) being air-permeable.

3. The ventilation system (1 ) as claimed in claim 2, wherein the main section (12a) of the one or more at least partially air-permeable curtains (12) has a height about equal to a space between a top of a bottom crate and a top of a top crate.

4. The ventilation system (1 ) as claimed in claim any one of claims 1 to 3, wherein a top cover (16) of the enclosure (6) blocks airflow and has a hole which cooperates with the fan.

5. The ventilation system (1 ) as claimed in any one of claims 1 to 4, wherein the one or more at least partially air-permeable curtains (12) are weighted at the bottom to restrict airflow at a base of the enclosure.

6. The ventilation system (1 ) as claimed in any one of claims 1 to 5, wherein the enclosure (6) is made up of four at least partially air-permeable curtains (12) that are connected at their corners or along free edges at which they meet with attachment means.

7. The ventilation system (1 ) as claimed in claim 6, wherein the attachment means are hook and loop fasteners.

8. The ventilation system (1 ) as claimed in claim 2, wherein the bottom skirt (12b) of the curtains (12) is made of polyvinyl chloride sheeting.

9. The ventilation system (1 ) as claimed in claim 2, wherein the main section (12a) of the curtains (12) is made of shade netting.

10. The ventilation system (1 ) as claimed in claim 9, wherein the shade netting has a shade percentage of between 40% and 60%.

1 1. The ventilation system (1 ) as claimed in claim 4, wherein the top cover (16) is made of polyvinyl chloride sheeting.

12. Apparatus (30) for rearing insects comprising clusters (2) of one or more stacks of crates (4) adapted to contain immature phases of insects, wherein each cluster (2) is provided with a ventilation system (1 ) as claimed in any one of claims 1 to 1 1.

13. Apparatus (30) for rearing insects as claimed in claim 12, wherein a cluster (2) is made up of two rows of four stacks of crates (4).

14. Apparatus (30) for rearing insects as claimed in claim 13, wherein the rows are spaced between 140 and 160 mm apart from each other.

15. Apparatus (30) for rearing insects as claimed in claim 13, wherein the four stacks are spaced between 35 and 55 mm apart from each other.

16. Apparatus (30) for rearing insects as claimed in any one of claims 12 to 15, wherein the crates (4) are stacked on trolleys (18).

17. Apparatus (30) for rearing insects as claimed in claim 16, wherein each trolley (18) has a pin (22) that slots into a corresponding guiding rail (24) located on a floor over which the trolley (18) moves.

18. A process of rearing insects comprising: placing (100) immature phases of insects and feed into crates (4) and stacking (102) the crates (4) onto trolleys (18); arranging (104) the trolleys (18) into a cluster (2) beneath a fan; forming (106) an enclosure (6) around the cluster (2) with one or more at least partially air-permeable curtains, the enclosure (6) having a top opening (8) which cooperates with the fan; and ventilating (108) the enclosure (6) by operating the fan (10) so as to suck air out of the enclosure.

19. The process for rearing insects as claimed in claim 18, wherein the immature phases of insects are black soldier fly larvae.