Frass processing plant from an insect farm

Abstract

The present invention relates to a processing installation for frass from an insect farm, characterized in that the frass stream feeds a diverter having at least two outlets to direct the frass to at least two different processing systems. Abstract figure: Figure 1

Description

Title of the invention: Installation for processing frass from an insect farm Scope of the invention

[0001] The present invention relates to the field of frass processing, which is a by-product of insect rearing consisting of a mixture of insect larva excrement and substrate remains not consumed by the insect larvae and larval molts. The present invention relates in particular to the frass of the black soldier fly Hermetia illucens.

[0002] For some years now, the agri-food industry has been interested in the breeding of insects, and in particular the black soldier fly, because of their ability to convert organic waste, such as fruits and vegetables (including coffee pulp), meat and fish, bread and cereals and manure, into products of market value, such as animal feed (terrestrial or aquatic) or ingredients for animal feed, pet food, food for human consumption and plant growth supplements.

[0003] Installations for the mass rearing of insects, and in particular black soldier flies, have therefore been developed and solutions have been sought to valorize the excrement and waste resulting from these industrial farms.

[0004] It has therefore become necessary to provide on industrial insect breeding sites, and in particular black soldier fly breeding sites, equipment to automatically collect the frass and transform it to allow its valorization in the form of value-added plant protection products. State of the art

[0005] Prior art is known in the United States Patent US9844223 describing an apparatus and methods for producing insecticidal excrement of black soldier fly (Hermetia illucens) and for using the excrement for nutritional and insect pest control purposes in soils and / or on foliage. The methods include methods for using black soldier fly excrement to reduce damage to crops caused by wireworms (i.e., click beetle larvae, in the family Elateridae) and / or other beetle pests (i.e., beetles).

[0006] US patent 10842138B1 relates to a system and method for containing and rearing insect larvae for the processing of organic matter. The system comprises an arrangement of shelves containing trays for culturing the larvae and collecting excrement. The shelves are maintained in a controlled environment and adapted to receive applications of raw material prepared for conversion into insect biomass. A larva and excrement collection system is also provided.

[0007] Patent CN110961341A describes a screening installation for separating worm pupae, larvae and excrement of yellow mealworms, comprising a rectangular housing with a larvae sieve, a worm excrement sieve, and a vibrating mechanism driving the mixture containing the worm pupa, larva and worm excrement towards the outlet end of the installation. Disadvantages of the state of the art

[0008] The solutions proposed in the state of the art are not suitable for valorizing the frass produced by an industrial insect breeding facility with controlled production of plant protection products suitable for use as fertilizer.

[0009] Indeed, the composition and volumes of frass are not constant and depend on production conditions. Furthermore, the frass valorization system must be able to operate independently from other areas of an insect rearing facility, and in particular from the rearing area and the larval processing area, in order to have a robust overall installation. Solution provided by the invention

[0010] In order to remedy these drawbacks, the present invention relates in its most general sense to a frass processing installation from an insect farm characterized in that the frass flow feeds a switch having at least two outlets to direct the frass to at least two different processing systems.

[0011] Advantageously, one of the outputs of said switch leads to a storage system.

[0012] Advantageously, one of the outputs of said switch leads to a thermal treatment system for devitalizing residual living matter.

[0013] Advantageously, one of the outlets of said switch leads to a granulation system.

[0014] According to a preferred variant, said switch has three outlets consisting of: - a first outlet leading to a storage system, - a second outlet leading to a thermal treatment system for devitalizing residual living matter, - a third outlet to a granulation system.

[0015] Advantageously, said switch is a switch that can be controlled by means of pneumatic cylinders.

[0016] Advantageously, the collected frass is transported to the switch by a bucket conveyor.

[0017] According to a preferred variant, the frass stream originates from a granulometric separation of frass and insect larvae.

[0018] Advantageously, the installation includes a buffer hopper providing a waiting storage allowing the arrival of the material to be screened to be adapted according to the capacity of the screen, via a controlled airlock.

[0019] According to a particular embodiment, the installation includes an additional feeding chamber for the introduction of a mixture of larvae and frass from another rearing site.

[0020] Detailed description of a non-limiting example of embodiment

[0021] The present invention will be better understood upon reading the following description, concerning a non-limiting example of an embodiment illustrated by the accompanying drawings where:

[0022] [Fig-1] [Fig.1] represents an example of a functional diagram of the invention. General principle of the invention

[0023] The present invention relates to an installation for producing, under industrial conditions, frass conditioned in the form of granules to allow its spreading as a fertilizer product with standard agricultural equipment or for use by consumers in their garden, vegetable garden and indoor or balcony plants.

[0024] Raw (unprocessed) frass is a powdery product with a moisture content varying between 35% and 65%, a density of approximately 300 kg / m³, and containing nitrogen, phosphorus, and potassium, making it a material of choice for the manufacture of organic fertilizers. Raw frass also contains chitin, which has biostimulant properties.

[0025] The invention relates to the transformation of frass into granules for agricultural or consumer use (houseplants, vegetable gardens, flower gardens), in the form of fertilizer spreading. These granules, with a diameter of 4 to 5 mm, are stable and resistant; they have a density of approximately 600 to 700 kg / m³, a moisture content between 7% and 15%, and good resistance to fragmentation while easily disintegrating when in contact with water.

[0026] Typically, an insect production facility comprises three main areas: - a rearing area in which insect larvae are raised to maturity, - an area for processing insect larvae (in particular to transform them into flour rich in protein and oil), - an area for the valorization of frass. Since the rearing area supplies both the larvae processing area and the frass processing area, it is essential that each area can operate independently. Therefore, the frass processing area has redundancy to avoid becoming a bottleneck for the rest of the plant (particularly in the event of a breakdown or maintenance on one of the pieces of equipment).

[0027] Thus, the frass valorization zone offers three possibilities: - storage of raw frass in skips, - heat treatment of raw frass, - granulation of frass. Transfer of the larvae and frass mixture

[0028] Fresh larvae are produced in the rearing area. The larvae develop and grow directly in their rearing substrate, in the multi-stage modules.

[0029] During larval growth, the substrate is consumed by the larvae, and the rearing medium gradually transforms into frass (a mixture of larval excrement, substrate remnants, and larval molts). When the larvae have reached their optimal size and age for their nutritional profile, and when the rearing medium is ready to be sieved, the multi-stage modules are returned to the rearing area, and the contents of the modules are conveyed to a sorting area by chain conveyors. The larval and frass mixture is transferred from an automatic turner to a hopper located above a separating sieve. From the hopper, the sieve is fed via an airlock positioned below the hopper. The flow rate of the larval and frass mixture sent to the sieve is controlled by changing the rotation speed of the airlock.

[0030] It is also possible to inject raw frass or a mixture of frass and larvae from another rearing site or from storage bins directly into the handling line in order to transform it. Sieving

[0031] The mixture of frass and larvae can be sorted by particle size. Indeed, frass is mainly composed of a moist powder with a particle size of less than one millimeter. The larvae can be considered as cylinders with a diameter between 3 and 5 mm and a length between 8 and 12 mm. Separation by particle size is therefore used by employing a "trampoline" type sieve. The mesh of the sieve changes with a trampoline effect, that is to say, the mesh expands and then contracts, creating a bouncing effect of the material. This sieve is particularly suitable for clogging materials such as frass, which is a powdery material with a variable moisture content between 35 and 65% RH. The frass passes through the mesh progressively as it travels the length of the sieve. The frass is collected below the sieve. The larvae remain above the mesh and travel along the entire length of the sieve.

[0032] The width and length of the sieve are chosen to ensure the processing of the nominal instantaneous flow of incoming material (mixture of larvae and frass), and to ensure the best separation between the larvae and the frass, with a compromise between purity and yield.

[0033] The parameterization leads to prioritizing either the purity of the larvae fraction or the purity of the frass fraction.

[0034] The more the objective is to purify the larval fraction, the more larvae must be allowed to pass through the frass. Conversely, if the objective is to maximize yield, it is essential to prevent larvae from passing through the frass. The decision was made to accept some frass in the larvae in order to reduce the larval content in the frass to less than 3% by weight.

[0035] This first sieving step using the trampoline sieve separates the powdered frass from the larvae and other foreign bodies of a size greater than or equal to that of the larvae. The larvae are then separated from the other larger bodies via a further sieving step using a circular screen. Sifted frass routing

[0036] The frass separated from the larvae by the trampoline sieve is collected by a chain conveyor directly under this sieve and directed to a bucket elevator which allows vertical handling of the frass.

[0037] At the bucket elevator jetty, a three-way switch allows the frass to be directed along one of the tracks:

[0038] Route 1 - To the storage system (bins) via a series of chain conveyors. This route allows the volume of frass to be processed to be modulated and provides flexibility to operations by desynchronizing the processing of larvae and the processing of frass. The operator can choose to store frass (and thus not prevent the transformation of larvae) initially, and then process it later without having to run two processing units simultaneously.

[0039] Route 2 - Towards a thermal treatment system, which makes it possible to produce raw unprocessed frass without residual live larvae towards external valorization routes such as methanization.

[0040] Route 3 - To the complete frass transformation line to produce frass granules used as fertilizer.

[0041] The rejects from the circular screen (frass in the form of plates or pellets) can also be injected into the conveyor under the screen. Functional diagram

[0042] Figure 1 illustrates the functional diagram of the frass processing plant. The contents of the multi-stage rearing modules come from the rearing area via a chain conveyor (1). The plant optionally provides for the possibility of also introducing a mixture of larvae and frass from another rearing site (3). The collected materials are transferred from a chain conveyor (2) to a buffer hopper (4) providing a waiting storage allowing the arrival of material to be sieved to be adapted according to the capacity of the sieve (6), via a piloted sluice gate (5).

[0043] The larvae separated by the sieve (6) fall into a collection chute (7) and are directed by a belt conveyor (9) to a circular screen (10) which separates the larvae from the residual frass and any foreign bodies larger than the larvae. This residual frass is returned after separation to the frass stream flowing in the chute (11) below the sieve (6).

[0044] This stream can also receive dewatered frass from a screw press (12). This screw press makes it possible to remove the frass accumulated in the hot water used to devitalize the larvae, to which particles of frass may remain stuck.

[0045] These different flows are grouped in a bucket elevator (13) feeding a three-way switch (14).

[0046] The first channel feeds a chain conveyor (16) that transfers the raw frass to bins (20). This chain conveyor (16) also receives flows from the other two channels. These bins (20) allow for the storage of frass exceeding the processing capacity of the processing unit, so that the contents can then be reintroduced into the processing circuit when capacity permits.

[0047] The second route transfers the frass to a thermal treatment system that eliminates any residual larvae potentially present in the frass. This allows the raw frass to be used directly, for example, by methanation. In this embodiment, this second route consists of a buffer hopper (17) and a thermal conditioner (18) that maintains the frass at the desired temperature for a specific duration (typically 90°C for 2 minutes). Once the frass has been thermally treated, it is sent to bins (20) via the chain conveyor (16).

[0048] The third path feeds the frass processing and conditioning unit (15), for example a drying and granulation unit for the formation of frass pellets. Excess material is transferred to skips (20), and the processed frass in pellet form is sent to a silo (21) for storage before shipment.

[0049] The set of bins (20) includes bins storing raw frass and / or bins storing heat-treated frass.

Claims

Claims

1. Installation for treating frass from an insect farm, characterized in that the flow of frass feeds a diverter having at least two outlets for directing the frass to at least two different treatment systems.

2. Frass processing installation according to claim 1 characterized in that one of the outputs of said switch leads to a storage system.

3. Frass treatment installation according to claim 1 characterized in that one of the outlets of said switch leads to a thermal treatment system for devitalizing residual living matter.

4. Frass processing installation according to claim 1 characterized in that one of the outlets of said switch leads to a granulation system.

5. Frass treatment installation according to claim 1 characterized in that the flow of frass feeds a switch having three outlets consisting of: - a first outlet opening onto a storage system, - a second outlet opening onto a thermal treatment system for devitalizing residual living matter, - a third outlet towards a granulation system.

6. Frass processing installation according to claim 1 characterized in that said switch is a switch which can be controlled using pneumatic cylinders.

7. Frass processing installation according to claim 1 characterized in that the collected frass is transported to the switch by a bucket conveyor.

8. Frass treatment plant according to claim 1 characterized in that the frass flow comes from a granulometric separation of the frass and insect larvae.

9. Frass processing installation according to claim 1 characterized in that it comprises a buffer hopper (4) providing waiting storage allowing the arrival of the material to be screened to be adapted according to the capacity of the screen (6), by means of a controlled lock (5).

10. Frass processing installation according to claim 1 characterized in that it comprises an additional feed lock for the introduction of a mixture of larvae and frass coming from another breeding site (3).

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