Rearing device for rearing insect larvae

Abstract

A rearing device for rearing insect larvae comprises an elongate rearing base (12) extending in axial direction. Also provided is a processing device with at least one processing member whereby a treatment can be performed along the rearing base. An axial guide (16) is provided substantially parallel to the rearing base, and the at least one processing member (25, 35, 45) is formed by a carriage (20, 30, 40) which is displaceable along the guide (16) between a first axial position relative to the rearing base (12) and a second axial position relative to the rearing base lying further along. The at least one processing member (25, 35, 45) provides an operative width which corresponds at least substantially with a width of the rearing base (12).

Description

[0001] REARING DEVICE FOR REARING INSECT LARVAE

[0002] The present invention relates to a rearing device for rearing insect larvae, comprising an elongate rearing base extending in axial direction, and a processing device with at least one processing member whereby a treatment can be performed along the rearing base, wherein an axial guide is provided at least substantially parallel to the rearing base, wherein the at least one processing member is provided by a carriage which is displaceable along the guide between a first axial position relative to the rearing base and a second axial position relative to the rearing base lying further along, and wherein the at least one processing member provides an operative width which corresponds at least substantially with a width of the rearing base.

[0003] A rearing device for insect larvae, particularly those of the black soldier fly, has for its object to provide an ideal environment for efficient production of larvae as a sustainable source of nutritious proteins and fats. A known device generally consists of large, closed containers or trays with a controlled temperature and humidity, in which organic waste material, such as food waste, are provided as rearing base. The larvae of the black soldier fly thrive at temperatures of between 25 and 35°C and a relative air humidity of about 50-70%. A constant supply of fresh organic material results in the growth and development of the larvae, which feed on the waste. After several weeks, the fully grown black soldier fly larvae can be harvested and processed into high-grade insect meal, which can then be used directly as feed for fish, livestock and poultry and as ingredient in animal feed or even food products for human consumption. Such a rearing device thereby contributes to a circular economy and a reduced pressure on traditional protein sources, while simultaneously enhancing processing of organic waste and so supporting environmentally friendly food production.

[0004] It is particularly the larvae of the black soldier fly that have been found to be an undemanding and particularly efficient means for a conversion from organic waste to nutritious proteins. The optimal rearing conditions however require a conditioned climate which can generally only be realized in a closed, covered breeding environment such as a production facility or cellar. This requires considerate investment and demands optimal use of the available production means. A factor is here a packing density with which the rearing device can be utilized. In addition to requiring their own footprint, the known containers or trays also require a relatively great deal of servicing space, which is needed to perform inspections and treatments on or on the rearing base during a breeding cycle, which is usually done manually.

[0005] A rearing device which utilizes an available floor area in the breeding environment more efficiently is described in International patent application WO 2023 / 161750 of applicant. The rearing device known therefrom comprises an elongate rack with a rack bottom over which a rearing base extends over at least substantially a full length. The rearing base makes use here of a displaceable cloth and is flanked on either side by a set of upward extending walls. Sliding the cloth into or out of the rack enables respectively a fresh rearing base to be introduced into the rack or a rearing area to be harvested to be removed therefrom. The known rearing device provides thereby a significant improvement in efficiency relative to rearing in optionally stacked containers or trays, but still requires lateral servicing space for manual access for the purpose of interim treatments on or at the rearing base.

[0006] The present invention has for its object, among others, to provide a rearing device which allows in this respect a higher packing density.

[0007] In order to achieve the stated object a rearing device of the type described in the preamble has the feature according to the invention that the processing device comprises a dispensing device whereby a substrate is spreadable over the rearing base, that the at least one processing member comprises a belt with a turnaround in which the belt switches from a feed direction to a return direction, that the belt with the turnaround is co-displaced by the carriage, that the belt can be reached by feed means at the first position to receive the substrate, and that the belt dispenses the substrate from the turnaround.

[0008] Treatments on or at the rearing device over the path of the guide can thus be performed wholly from the carriage without having to be accessible for further human intervention. The carriage can advantageously be guided from an end surface of the rearing base to an opposite outer end thereof in order to thus cover the whole rearing base. The rearing device can be placed directly adjacently of a further rearing device without taking into consideration passageways or further servicing space. This results in a particularly high packing density and thereby in a particularly efficient use of available space in the rearing environment.

[0009] Owing to the invention, it is relatively simple to provide the larvae with supplemental feed if the breeding substrate is at risk of becoming depleted. For this purpose the device comprises a dispensing device in the form of a belt with a turnaround in which the belt switches from a feed direction to a return direction. The turnaround where the cloth changes direction provides for dispensing of the substrate co-displaced to this position. Because this turnaround is carried along the rearing base in axial direction by the carriage, fresh substrate will be continuously dispensed thereunder onto the rearing base while the carriage moves. A fresh growth substrate can thus be distributed along the rearing base remotely in order to thereby enhance further development of the larvae. The belt advantageously comprises a cloth (film), particularly a plastic cloth, more particularly a fibre-reinforced plastic cloth. Such a cloth can if desired be cleaned in efficient and effective manner for subsequent use.

[0010] In its movement from the first axial position to the second and vice versa the carriage co-displaces the belt, this thereby obtaining an increasingly greater length relative to its starting position. In order to facilitate this greater length and to be able to take it in in opposite direction a preferred embodiment of the rearing device has the feature according to the invention that the belt comprises a first outer end and an opposite, distal outer end, wherein the first outer end is provided by a winding device. At the first outer end the belt can thus be extended or shortened in simple manner by respectively unwinding or winding up by means of the winding device. The system remains compact hereby. The opposite, distal outer end can likewise be fed by a winding device, although in a practical embodiment the rearing device is characterized in that the distal outer end is fixed to the carriage beyond the turnaround. The distal outer end can particularly be connected fixedly to the carriage beyond the turnaround.

[0011] Due to evaporation, an upper layer of the rearing bed on the rearing base may dry out over time, this having an adverse effect on development and growth of the larvae. In that case it is desirable to replenish the upper layer. With this in mind, a further particular embodiment of the rearing device has the feature according to the invention that the carriage comprises a substrate improvement device comprising a driven rotation shaft in the carriage, from which extends at least one paddle which agitates, particularly mixes up, a rearing bed on the rearing base when the rotation shaft rotates. In practice, agitation of the rearing bed, wherein the drier top layer is switched with substrate from layers lying thereunder, has been found to be an effective measure for maintaining a uniform average degree of moistness over a thickness of the rearing bed.

[0012] In order to harm the insect larvae as little as possible when agitating the rearing bed a preferred embodiment of the rearing device has the feature here that the at least one paddle is in each case formed by a flexible fin of an optionally natural rubber. The relatively soft rubber of the paddle members has been found to cause no or hardly any damage to the larvae while the substrate is being mixed up thereby. A further particular embodiment of the rearing device has the feature according to the invention that the carriage comprises a moistening device which is able and configured to moisten the rearing base over a width of the rearing base, in the case that the rearing bed as a whoie contains over a thickness thereof insufficient moisture to maintain a sufficient degree of moistness for optimal development of the larvae, the moistening device on the carriage can be utilized to supplement an additional amount of moisture in the rearing bed. Optimal moisture management can thus be guaranteed over the duration of a rearing cycle. For more permanent controlled moisture management it is also possible to make use of a further particular embodiment of the rearing device which is characterized according to the invention in that a liquid-carrying conduit is provided therein, which extends over a length of the rearing base and feeds one or more nozzles with mutually overlapping spray patterns.

[0013] For uninterrupted operation of the operating device it is advantageous for the carriage to be able to travel along a path which is free of obstacles between the starting position and end position. It is for this purpose, among others, that a further particular embodiment of the rearing device has the feature according to the invention that the rearing base extends over a continuous gutter bottom between opposite walls of a gutter, which extends from the first position to the second position. The carriage here travels uninterruptedly over the continuous gutter bottom and the rearing base situated thereon. A further particular embodiment of the rearing device has the feature here that the opposite walls of the gutter are form- retaining and form the guide over which the carriage is movable. The carriage can be self-propelled. In an embodiment the rearing device is for this purpose characterized in that the carriage is self-propelled and comprises a drive motor which propels the carriage. The carriage can be embodied with or without its own drive motor. For this purpose an alternative embodiment of the rearing device is characterized according to the invention in that the carriage comprises a drawn carriage, wherein the carriage is coupled to a winch on a front side. The winch can for instance be provided on a front side by a winding device which is motor-driven and draws along the carriage. After reaching the end position, the carriage can if desired be returned to the starting position manually or with a proximal winding device on the belt.

[0014] Packing the rearing device closely together side by side with one or more similar further rearing devices enables optimal use of an available floor area in the rearing environment. A further increase of a production capacity can also be achieved vertically. For this purpose a further particular embodiment of the rearing device has the feature according to the invention that the rearing base forms part of a number of similar rearing bases which are placed one above the other at different levels, wherein the carriage is movable between successive levels. The available space is utilized particularly efficiently in such a stacked rearing environment. An intermediate space between different levels need not be (much) greater than is necessary for passage of the carriage, this enabling the rearing bed to for instance be inspected using a camera system and, if necessary, be subjected to a process. The invention will be further elucidated hereinbelow with reference to an exemplary embodiment and an accompanying drawing. In the drawing:

[0015] Figure 1 is a side view of a first exemplary embodiment of a rearing device according to the invention;

[0016] Figure 2 is a first embodiment of processing means for the rearing device of figure 1;

[0017] Figure 3 is a second embodiment of processing means for the rearing device of figure 1;

[0018] Figure 4 is a third embodiment of processing means for the rearing device of figure 1; and

[0019] Figure 5 is a front view of the processing device of figure 3 in the rearing device of figure 1.

[0020] It is otherwise noted here that the figures are purely schematic and not all drawn to (the same) scale. Some dimensions in particular may be exaggerated to greater or lesser extent for the sake of clarity. Corresponding parts are designated in the figures with the same reference numeral.

[0021] The rearing device shown in figure 1 comprises a shelving unit 10 of elongate steel or aluminium racks 15, typically with a length of several metres to several tens of metres and typically with a width of 100 to 180 centimetres. Each rack 15 provides over substantially full length thereof a gutter-like rearing base 12 on which insect larvae, particularly those of the black soldier fly, can be reared. The gutter bottom 12 is covered with a film pulled into the rack, as described in International patent application

[0022] WO 2023 / 161750 of applicant the content of which must be deemed as referred to and included herein. This is a plastic film with a thickness of several tenths of a millimetre to several millimetres, for instance of polypropylene or EPDM rubber (ethylene propylene diene monomer), which also extends upward over a certain height against the walls of the relevant rack 15 in order to reduce the chances of larvae crawling upward along the walls. A substrate 14 of an organic material, such as for instance kitchen and garden waste (green waste), is dropped onto the rearing base, this substrate serving as food source for young larvae which will thrive and grow to an adult stage therein. The larvae can already be pre-mixed with the substrate 14, but can also be distributed thereover afterward. The rearing device moreover comprises a processing device 20 with one or more processing members 25 with which a treatment on or at rearing base 12 can be performed.

[0023] In the example of figure 1 the processing device comprises a dispensing device in the form of a carriage 20 with which a belt 25 is co-dispiaced from a winding device, see also figure 2. The carriage runs from a first end surface of a rack 15 to an opposite outer end of the rearing base over a guide. The guide is formed by steel rails 16 which extend from the upright walls 17 of a rack 15, see also figure 5. Carriage 20 covers almost a full width of the relevant rack 15. The drawn belt 25 is formed by a film having roughly the same width as the rearing base 12 and can be formed from the same or a similar plastic film as the one covering the rearing base. With a view to sustainability, use is in this example made in respect of belt 25 of a smooth fibre-reinforced plastic cloth, for instance of polypropylene. On a front side of the carriage the belt comprises a turnaround 22 in which the belt 25 switches from a feed direction to a return direction, see also figure 2. Beyond the turnaround 22 the belt is attached to the frame of carriage 20.

[0024] At the first end surface the belt is fed a substrate material 14 by a feed device 50, this material being supplied at a substantially constant speed. The carriage 20 is drawn from the opposite outer end of the rack by a winch (not shown) and comprises for this purpose on either side a hook 24 to which a winch cable can be coupled. The substrate dropped onto belt 25 is co-displaced with the belt and falls on the front side, at the position of turnaround 22, from belt 25 onto rearing base 12 or, in the case of supplementation, onto a rearing bed lying thereon. A winding device 55 continuously provides a fresh belt surface onto which the fed substrate is supplied, this substrate falling off the belt further along at the position of the turnaround 22 which is now further removed. In this way the rearing base 12 can be gradually provided with the substrate 14 or replenished therewith over the whole length and width. When the end position on the opposite outer end of the rearing base 12 is reached, the winch cable is uncoupled or payed out and the carriage can be brought in again with winding device 55 and optionally be displaced to a subsequent level in the shelving unit 10.

[0025] In an alternative embodiment the rearing device is provided with a similar carriage 30 in which a substrate improvement device 35 is concealed. Figure 3 shows this embodiment in a schematic side view, while figure 5 show's a front view. Just as the dispensing device of figure 2, the carriage 30 can be drawn along in the longitudinal direction of rearing base 12 or, as in this case, take a self-propelled form. For this purpose an electric motor (not shown) is provided therein, which is provided on a long power cable from a reel at one of the two outer ends with an electric power supply. The electric motor drives one or more of the wheels 31, 33 of the carriage with which the carriage runs over guide 16, or can drive an individual wheel which is provided specifically for this purpose and may or may not engage on the same guide 16. It is particularly in this latter case that a toothed wheel can advantageously be applied, this engaging in a gear rack which extend over the length of rearing base 12. Such a gear rack drive is able to transmit considerably more traction.

[0026] Carriage 30 comprises a rotation shaft 32 which is for instance coupled via a transmission to the same motor that propels carriage 30, or is driven by a separate electric motor in carriage 30. The rotation shaft 32 extends over substantially a full width of rearing base 12 and carries over this width a set of paddle members 35 which will agitate the substrate 14 on rearing base 12. For the paddle members 35 it is possible to apply all manner of shapes, dimensions, numbers and materials which are able to take up and turn over the loose substrate 14 during a rotation round rotation shaft 32. In this example the paddle members 35 are in this context formed by flexible fins of an optionally natural rubber which mix up the substrate 14. Substrate material 14 in a drier top layer of the rearing bed will hereby be switched with moister material 14 of a substrate layer lying thereunder. The relatively mild agitation by means of such flexible rubber fins 35 results in no or hardly any damage of any significance to the lame. This ultimately results in a more homogenous moisture distribution in the rearing bed and also in aeration thereof, both of which enhance the development of the larvae.

[0027] In a third exemplary embodiment the carriage 40 comprises a moistening device in the form of one or more nozzles 45, see figure 4. The carriage is seif-propelled and comprises for this purpose an electric motor (not shown) as drive. The sprinklers 45 are fed by a pump (not shown) in the carriage 40, whereby a fine mist is distributed over a full width of rearing bed 12. A reservoir in carriage 40 can serve as supply and source of spraying liquid, or the pump can be connected with a flexible hose to a water conduit.

[0028] In this latter case the hose is preferably carried from a reel to the carriage 40 and unwound as desired. If desired, nutrients can be added to the spraying liquid.

[0029] For a more permanent moistening of rearing bed 12 a fixed liquid-carrying conduit 60 can also be provided at the top of each rack, this conduit extending here over a length of the rearing base 12 as shown in figure 1. Coupled thereto is a number of nozzles 65 which are thus fed by conduit 60 and dispense mutually overlapping spray patterns.

[0030] A total rearing device comprises one or more shelving units 10 of the type as shown in figure 1, each with one or more of the shown racks. Each level and / or each shelving unit 10 can be provided with a carriage 20, 30, 40 which travels or is drawn therein, but a carriage 20, 30, 40 can also be displaced from one rack 15 to another rack 15. The feed device 15 for the substrate 14 can be embodied on a mobile chassis in order to likewise be moved from one shelving unit 10 to another in simple manner. A lifting device is advantageously provided therein in order to enable the substrate feed to be displaced over the different levels in a shelving unit. Although the invention has been further elucidated above with reference to only a single exemplary embodiment, it will be apparent that the invention is by no means limited thereto. On the contrary, many variations and embodiments are still possible within the scope of the invention for a person with ordinary skill in the art. Other types of processing device or means can thus particularly also be provided in or on the carriage, and different processing means can thus particularly also be combined in the carriage. In combination with the guide over the full length of the rearing bed, the carriage provides a particularly compact and space-saving option for performing treatments on the rearing bed during a rearing cycle, if desired.

Claims

Claims:

1. Rearing device for rearing insect larvae, comprising an elongate rearing base extending in axial direction, and a processing device with at least one processing member whereby a treatment can be performed along the rearing base, wherein an axial guide is provided at least substantially parallel to the rearing base, wherein the at least one processing member is provided by a carriage which is displaceable along the guide between a first axial position relative to the rearing base and a second axial position relative to the rearing base lying further along, and wherein the at least one processing member provides an operative width which corresponds at least substantially with a width of the rearing base, characterized in that the processing device comprises a dispensing device whereby a substrate is spreadable over the rearing base, that the at least one processing member comprises a belt with a turnaround in which the belt switches from a feed direction to a return direction, that the belt with the turnaround is co-displaced by the carriage, that the belt can be reached by feed means at the first position to receive the substrate, and that the belt dispenses the substrate from the turnaround.

2. Rearing device according to claim 1, characterized in that the belt comprises a cloth, particularly a plastic cloth, more particularly a fibre-reinforced plastic cloth.

3. Rearing device according to claim 1 or 2, characterized in that the belt comprises a first outer end and an opposite, distal outer end, wherein the first outer end is provided by a winding device.

4. Rearing device according to claim 3, characterized in that the distal outer end is fixed to the carriage beyond the turnaround.

5. Rearing device according to one or more of the preceding claims, characterized in that the carriage comprises a substrate improvement device comprising a driven rotation shaft in the carriage, from which extends at least one paddle member which agitates, particularly mixes up, a rearing bed on the rearing base when the rotation shaft rotates.

6. Rearing device according to claim 1, characterized in that the at least one paddle member is in each case formed by a flexible fin of an optionally natural rubber.

7. Rearing device according to one or more of the preceding claims, characterized in that the carriage comprises a moistening device which is able and configured to spray the rearing base over a width of the rearing base.

8. Rearing device according to one or more of the preceding claims, characterized in that a liquid-carrying conduit is provided therein, which extends over a length of the rearing base and feeds one or more nozzles with mutually overlapping spray patterns.

9. Rearing device according to one or more of the preceding claims, characterized in that the rearing base extends over a continuous gutter bottom between opposite walls of a gutter, which extends from the first position to the second position.

10. Rearing device according to claim 9, characterized in that the opposite walls of the gutter are form-retaining and form the guide over which the carriage is movable.11 . Rearing device according to one or more of the preceding claims, characterized in that the carriage is self-propelled and comprises a drive motor which propels the carriage.

12. Rearing device according to one or more of the preceding claims, characterized in that the carriage comprises a drawn carriage, wherein the carriage is coupled to a winch on a front side.

13. flearing device according to one or more of the preceding claims, characterized in that the rearing base forms part of a number of similar rearing bases which are placed one above the other at different levels, wherein the carriage is movable between successive levels.

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