Patent Description:
When rearing insect larvae, it is important to homogenously provide fresh conditioned air, i.e. air with a set temperature, moisture, O<NUM> and CO<NUM> content, to all insect larvae, in particular due to the heat, moisture and CO<NUM> production of the larvae and the substrate and to establish an optimal growth climate. In conventional rearing facilities insect larvae grow on a substrate in crates. In other words, inside the crates there is a biomass consisting of larvae and a substrate, which may comprise feed for larvae, insect droppings, insect skin parts, microorganisms, etc. Air circulation is obtained by fans. This, however, is only feasible for a low-density scenario. If more crates per room are used, the effectiveness of the air circulation is reduced and at some point the limits of such a system are reached. In conventional systems, crates are used which do however not yield optimal homogenous climate conditions for all scenarios.

<CIT> describes a method and system for controlling the air climate in an insect rearing climate housing. <CIT> discloses a method and system for breading insects, using a plurality of individual crates, wherein at least a portion of each crate is filled with a substrate, containing feed stock, and immature phases of insects. <CIT> discloses an insect breeding system for the breeding of insect larvae, comprising a multitude of similar, stackable crates, a climate housing and crate stacking equipment.

It is therefore desirable to provide a system which allows high-density rearing of larvae in large quantities by improving the air circulation in the room. In particular, a directed airflow over each individual crate and conditioned air to optimise the biomass to air energy transfer shall be provided. Furthermore, the air has to be extracted from the room without allowing heat and moisture to build up in order to have an optimal growth climate for the insect larvae.

These objects are solved by the present invention as defined in the claims.

In particular, the present invention concerns a system for providing conditioned air to a room or storage hall for rearing insect larvae as defined according to claim <NUM>. The system comprises crates for storing the insect larvae, wherein the crates are stackable to form a vertical column and wherein the crates comprise lateral cutouts disposed on opposite sides. An air inlet duct for individually providing conditioned air to the crates is disposed in a vertical direction and comprises at least one nozzle for each crate in a column. The position of the at least one nozzle corresponds to the position of the lateral cutout of the respective crate. The system further comprises an air outlet duct, wherein the air outlet duct is disposed in a vertical direction and wherein the air outlet duct is disposed on a side of the stacked crates opposite to the air inlet duct.

Preferably, the air is conditioned to have a specific temperature, humidity, speed/pressure and/or CO<NUM> proportion. The air inlet duct may be formed of a bellow to provide uniform air pressure to each crate. The air inlet duct may comprise three or five nozzles per crate. The air inlet duct may provide conditioned air to two columns of stacked crates which are positioned opposite to each other with respect to the air inlet duct.

The air outlet duct is formed by a space between two adjacent columns of crates. Two columns of stacked crates each may have one air inlet duct to provide conditioned air in between and two air outlet ducts on the respective outsides of the columns. A suction force may be provided to suction the exhaust air through the air outlet ducts. Preferably a space is formed above the air outlet ducts to provide a uniform suction force to all air outlet ducts.

The invention will be described with reference to the accompanying figures.

The invention concerns a heating, ventilation and air conditioning (HVAC) system directed towards providing a suitable environment for rearing of insect larvae. The larvae may grow on a substrate which provides nutrition, i.e. a nutritive medium. The medium may comprise organic waste or other types of nutrition which is suitable for insect larvae and allows them to grow. Thereby, the substrate itself contains microorganism that also grow and produce heat and CO<NUM>. The larvae together with the substrate are stored in stackable crates <NUM>, which may be rectangular. The walls of the crates <NUM> themselves are preferably airtight. The crates <NUM> are stacked to form a column and a plurality of columns is stored adjacent to each other to form rows. Multiple rows may be stored adjacent to each other, thus forming walls and corridors.

Stackability is achieved e.g. by self-centring elements on the crate walls which allow them to be stacked vertically and thereby roughly seal them in an airtight manner. However, other means to allow the crates <NUM> to be vertically stacked may be provided. Preferably, a column of crates <NUM> comprises between three and thirty crates <NUM>. Thereby high-density of larvae and a large production quantity are achieved.

Since the larvae have to be supplied with fresh air, cutouts <NUM> are formed in the crates <NUM> to allow air to pass through. The cutouts <NUM> are formed on opposite sides, preferably on the shorter sides, but may also be provided on all four sides. The cutouts <NUM> may thus be disposed laterally.

The crates <NUM> are preferably about <NUM> high and have a height from the bottom of the crate <NUM> to the cutout <NUM> of at least <NUM>, in order to allow a substrate or nutritive medium height of <NUM>. More preferably the height from the bottom of the crate <NUM> to the cutout <NUM> is <NUM> which leads to a cutout <NUM> height of <NUM>. The width of the cutout <NUM> thereby is preferably <NUM>. The area of the cutout <NUM> may thus be approximately <NUM><NUM>. The crates preferably have a length of <NUM> - <NUM>, a width of <NUM> - <NUM> and a height of <NUM> - <NUM>. The crates <NUM> may have structural features, such as grooves and protrusions, which allow them to be stackable. Furthermore, the crates <NUM> may each include an RFID chip, a barcode, a QR code or the like which allow an identification of the crate <NUM> and automated processing.

However, when the crates <NUM> are simply stacked in a room to form rows and columns and the room is ventilated by conventional fans, it is difficult to provide a homogenous airflow through the crates <NUM>, especially if the number of crates <NUM> is increased in order to scale up the rearing. Thus, the present invention provides a directed air flow over each individual crate <NUM>. Furthermore, the air may be carefully conditioned to ensure optimal temperature, moisture and CO<NUM> content in the air. Therefore, each crate <NUM> may have its own individual air supply.

According to the invention, an air inlet duct <NUM> is formed adjacent to a column of stacked crates <NUM> to provide conditioned air. The air inlet duct <NUM> may be disposed in a vertical direction, wherein vertical describes the direction perpendicular to the ground. The air inlet duct may <NUM> also be disposed in a horizontal direction, wherein horizontal describes the direction parallel to the ground. Air outlets, which may be designed as openings or nozzles <NUM> in the air inlet duct <NUM>, are formed in intervals corresponding to the cutouts <NUM> of the crates <NUM> when in a stacked arrangement. The nozzles are preferably arranged between <NUM>-<NUM> above the bottom line of the cutout <NUM>. At least one opening and maximum ten openings are provided per crate <NUM>, but one to five openings per crate <NUM> may be preferred. By designing the openings as nozzles <NUM>, a directed air flow can be assured and an optimised heat distribution can be achieved. , the nozzles <NUM> serve to direct and/or regulate the air flow. The diameter of the openings or nozzles <NUM> may be adaptable.

The crates <NUM> may be positioned behind each other and the nozzles <NUM> may provide multiple crates <NUM> with conditioned air. Thus, multiple columns of crates <NUM> may form a row in the direction of the airflow and the air will pass the crates sequentially in a horizontal direction. Thereby, one nozzle <NUM> and arrangement of nozzles <NUM>, respectively may serve one to eight crates <NUM>, preferably one to four crates <NUM> and most preferably only one crate <NUM>. In other words, the area served by one nozzle <NUM> or arrangement of nozzles <NUM>, respectively may be less than <NUM><NUM>, preferably less than <NUM><NUM> and more preferably less than <NUM><NUM>.

In order to ensure homogenous air pressure and flow rate of the conditioned air to each crate <NUM>, the vertical air inlet duct <NUM> may be a flexible air duct, e.g. formed of a bellow or a sock. The bellow can for example be filled with pressurised air which is then delivered to the crates <NUM> via the nozzles <NUM>. The bellow may have a circular cross section. If a bellow with circular cross section is used, the development of vortices inside the crate <NUM> may be avoided by arranging the nozzles <NUM> having an angular offset with respect to each other. But also other structures which are capable of evenly distributing air to each crate <NUM> with identical pressure and flow rate may be used for this purpose. There may be a pressurised chamber provided above the crate stack to ensure uniform distribution of air with respect to pressure, air flow and air parameters to all air inlet ducts <NUM>. In case of a vertical air inlet duct <NUM>, the bellow may be suspended from the ceiling. The nozzles <NUM> may be disposed on opposing sides of the air inlet duct <NUM> to be able to provide conditioned air to two columns of stacked crates <NUM> simultaneously. The air flow per crate may be less than <NUM><NUM>/h, preferably less than <NUM><NUM>/h, more preferably less than <NUM><NUM>/h. Simulations have shown that an appropriate volumetric air flow per crate may be <NUM><NUM>/h.

To find an optimum configuration, computational fluid dynamics (CFD) simulations have been performed. The use of one nozzle <NUM> which was directed perpendicular to the cutout <NUM> of the crate <NUM> led to a direct jet from inlet to outlet but seemed to have little interaction with the biomass. Other CFD simulations used three nozzles <NUM>, wherein one was perpendicular to the cutout <NUM> of the crate <NUM> and the other two were each offset by <NUM>° to the left and right, respectively. This yielded an even distribution and airflow through the crate <NUM> without flow leakage at the crate's cutout <NUM> opposite to the nozzles <NUM>. Thus, an interaction with the biomass throughout the crate <NUM> was achieved. Also by increasing the number of nozzles <NUM> to five which were offset by <NUM>° and <NUM>°, respectively, a good flow distribution in the crate <NUM> was observed. Again, no leakage at the crate's cutout <NUM> occurred and thus a good interaction of the conditioned air with the biomass can be expected. The external nozzles <NUM>, however, may create some recirculation phenomena. However, the present disclosure is not limited to one, three or five nozzles <NUM>, but also other numbers and angles might be used.

<FIG> shows the results of a CFD simulation using a simple model of crate <NUM> and three nozzles <NUM> from two different perspective views. As can be seen from the flow lines <NUM>, the conditioned air is distributed over a majority of the volume of crate <NUM> and thus provides a homogenous growth climate. <FIG> is a top view of an air inlet duct <NUM>, a crate <NUM> and an air outlet duct <NUM>. In this simulation, a bellow with three nozzles <NUM>, as described above, was used. Again, even distribution of conditioned air can be observed looking at the air flow lines <NUM>.

One key aspect of efficient air conditioning and circulation is the transport of exhaust air, i.e. heat, moisture and CO<NUM>, out of the room. Therefore, an air outlet duct <NUM> is formed by a space between two columns and rows of stacked crates <NUM> on a side of the crates <NUM> opposite to the air inlet duct <NUM>. Since cutouts <NUM> are provided on at least two sides of the crates <NUM>, the passing air can exit the crate <NUM> through the cutout <NUM> opposite to the air inlet duct <NUM>.

At the ceiling of the conditioned room at least one opening <NUM> formed in an exhaust duct <NUM> is provided to suction the exhaust air out of the room. The respective air flow <NUM> is shown in <FIG>) and b). The opening <NUM> may be formed as a single central exhaust opening <NUM> as shown in <FIG>. In case a plurality of openings is formed rather than a single central opening <NUM>, the positions of the openings <NUM> preferably correspond to the air outlet ducts <NUM>. With reference to <FIG>), CFD simulations have shown that a plurality of air outlet ducts <NUM> and respective openings <NUM>, preferably one for two adjacent columns of crates <NUM>, have yielded a preferred result. In order to efficiently suction the air out of the room, a suction force may be created. There is, however, the problem that the vacuum has to be uniformly distributed over all air outlet ducts <NUM>.

In order to avoid the need for providing separate openings for each pair of columns, i.e. for each air outlet duct <NUM>, a row of air outlet ducts <NUM> may be connected and provided with a single opening. In order to nevertheless provide a similar suction force for all air outlet ducts <NUM> in the row, and thus for all crates, the exhaust duct above the crates, i.e. the space above the crates leading the air from the outlet ducts to the opening, may be formed in a tapered form. In other words, the outlet ducts <NUM> are formed by a space between the columns of crates <NUM> while the exhaust ducts <NUM> are formed above the columns of crates <NUM> and are limited by the ceiling of the storage hall in which the crates <NUM> are located. The openings <NUM> thus are preferably formed in the ceiling of the storage hall. If a single central opening <NUM> should be used, the vacuum distribution between all air outlet ducts <NUM> may be improved by elevating the height of the exhaust duct <NUM>, i.e. enlarging the volume above the crates. Thereby, the suction force at the outlet points in one rearing compartment formed of rows and columns of crates <NUM> may be unified. An uniform air flow rate for each crate may thus be achieved, since all outlet openings from the outlet channel have the same suction force.

Preferably, the exhaust air which has already passed the interior of the crate <NUM> is removed by a suction force providing a negative pressure to the air outlet duct <NUM>. Also, the air outlet duct <NUM> formed by the stacked crates <NUM> may be wider than the air inlet duct <NUM>. For example, the air outlet duct <NUM> may be between <NUM> - <NUM> wide, more preferably <NUM>-<NUM> wide.

Hence, the outlet duct <NUM> may be formed of the space between stacked crates <NUM> and their walls, respectively, which form a channel, as well as ducts above the channel to provide a uniform suction force to the outlet channel.

Measurements of the inlet and exhaust air with respect to temperature, moisture and CO<NUM> may be performed in order to control the air conditioning and gather information about the insect larvae growth.

<FIG> shows two sectional views through the air conditioned room which are offset by <NUM>°. In this exemplary embodiment, the space between the columns forming the air inlet duct <NUM> and air outlet duct <NUM>, respectively, are <NUM> and <NUM>. Depending on the size and total number of the crates <NUM> and their positioning inside the conditioned room, also other measures may be appropriate.

<FIG> shows an exemplary arrangement of crates in an air conditioned room according to exemplary embodiments of the invention of three separate compartments with six lines of crates <NUM>, each compartment having three air inlet ducts <NUM> and four air outlet ducts <NUM>. Thus, the sequence in each compartment may be as follows: air outlet duct <NUM>, crates <NUM>, air inlet duct <NUM>, crates <NUM>, air outlet duct <NUM>, in a repetitive manner so that each inlet duct <NUM> is shared by two columns of crates <NUM>.

<FIG> show three exemplary embodiments of the invention which differ in the structure of the exhaust duct <NUM>. <FIG> both show a tapered exhaust duct <NUM> as explained above. In the compartment of <FIG> the elevated ceiling of the exhaust duct <NUM> is depicted. Furthermore, three different structures of fresh air supply are shown in <FIG>.

The effectiveness and performance of the present invention is not affected if some of the rows or columns of crates <NUM> are not in place. Thus, although a higher density of crates <NUM> and therefore a larger quantity of insect larvae can be conditioned at the same time, it is not necessary for the system to work properly to always have the room completely filled with crates <NUM>.

<FIG> is a schematic system diagram illustrating the air flow according to an embodiment the present invention. Return air from the conditioned rearing room may be mixed with fresh air and conditioned with respect to different parameters such as temperature (heating/cooling), CO<NUM> content, O<NUM> content and moisture. The conditioned air is supplied to the room as inlet air where it provides a healthy growth climate for the insect larvae. The return air coming from the rearing room may be partially recirculated and partially discharged to the environment as exhaust air. The recirculation rate may be between <NUM>-<NUM>%, depending on the conditions of the internal and external air. A power supply is provided to drive the air conditioning system. The measured data about the condition of the air, such as temperature, moisture and CO<NUM> content, is returned from the conditioning system and used to control said system and adapt the parameters if necessary in order to always have an optimal climate inside the room. The measurement points or sensors may be disposed in the inlet duct <NUM>, the outlet duct <NUM> or the crate <NUM> itself. A controller may be provided to analyse the parameters of the incoming and/or outcoming air and adapt the conditioned air correspondingly.

Claim 1:
System for providing conditioned air to a storage hall for rearing insect larvae, the system comprising:
- crates (<NUM>) for storing the insect larvae, wherein the crates (<NUM>) are stacked to form a vertical column of stacked crates (<NUM>) and wherein the crates (<NUM>) comprise lateral cutouts (<NUM>) disposed on opposite sides,
- an air inlet duct (<NUM>) for providing conditioned air to the crates (<NUM>), wherein the air inlet duct (<NUM>) comprises at least one nozzle (<NUM>) for each crate (<NUM>) in a column, wherein the position of the at least one nozzle (<NUM>) corresponds to the position of the lateral cutout (<NUM>) of the respective crates (<NUM>) in the column of stacked crates (<NUM>), and
wherein a plurality of columns of crates (<NUM>) are positioned to form rows and at least one row of crates (<NUM>) in a horizontal direction is provided with conditioned air by the respective at least one nozzle,
- air outlet ducts (<NUM>), wherein the air outlet duct (<NUM>) is formed by a space between two adjacent columns of crates (<NUM>) and is disposed on a side of the column of stacked crates (<NUM>) opposite to the air inlet duct (<NUM>), and
wherein a suction force is provided to suction the exhaust air through the air outlet ducts (<NUM>), and
wherein a space is formed above the air outlet ducts (<NUM>) and below the ceiling of the storage hall to provide uniform suction force to all air outlet ducts (<NUM>).