FACILITY FOR THE TREATMENT OF ARTHROPOD LARVAE, AND IN PARTICULAR INSECTS AND MORE SPECIFICALLY DIPTERAN LARVAE.

Abstract

The present invention relates to an installation for treating arthropod larvae, and in particular insects and more specifically ground dipteran larvae, characterized in that the separation of the solid and liquid phases is carried out by a decantation system making it possible to separate three phases (12): the outlet of the solid phase is connected to a flour dryer (60); a first liquid outlet feeds a glue water circuit; a second liquid outlet feeds the oil collection circuit, characterized in that said glue water circuit feeds equipment for treating ground larvae comprising the circuit for diluting the ground larvae and / or a glue water evaporator and / or a flour dryer. Abstract figure: figure 1

Description

Title of the invention: INSTALLATION FOR TREATING ARTHROPOD LARVAE, AND IN PARTICULAR INSECTS AND MORE SPECIFICALLY DIPTERAN LARVAE. Field of invention

[0001] The present invention relates to the field of industrial breeding of arthropods, in particular insects and more specifically Diptera for the purposes of food production.

[0002] The invention relates more particularly to the field of breeding arthropods, in particular insects and more specifically diptera, in particular the black soldier fly.

[0003] Arthropods have a number of characteristics that make them well suited for use in animal feed. Arthropods contribute a high protein content, while being rich in other beneficial nutrients such as fats, minerals and vitamins. Protein concentration levels in insect meals intended for animal feed vary between 55% and 75%. Insects are characterized by a higher feed conversion rate and can therefore become a very valuable feed source for farm animals. Insects are a natural component of the diets of animals such as carnivorous fish and poultry (for example, insects can provide up to 70% of the dietary requirements of trout).

[0004] Furthermore, these products also have a well-balanced nutritional profile to meet human dietary needs.

[0005] These considerations have led to the development of automated mass production of food from the breeding of arthropods, and more particularly insects, in industrial sites organized into complementary spaces specialized in laying, hatching, breeding, collection of mature animals and their treatment to extract the compounds of interest.

[0006] These industrial sites must be optimized to allow the industrialization of large volumes of larvae. One of the critical steps concerns the processing of live larvae in order to recover them, in particular the larvae of the black soldier fly Hermetia Illucens. The larvae are recovered in the form of protein meal and quality oil. The breeding environment in which the larvae evolve at the end of their growth cycle, called frass, is also recovered. Frass is made up of a mixture of larval droppings and residues of uneaten, dried and fermented substrate.

[0007] This processing step occurs after steps of egg production under industrial conditions, collection of eggs laid by female insects and concentration of larvae for breeding because it is necessary to group them as homogeneously as possible, in batches of neonate larvae all having the same stage of maturity in a given batch. Generally, laying takes place in a cage confining the flies in a closed space in which collectors are arranged having laying surfaces, for example grooved plates, on which the females deposit the eggs. These collectors are recovered to then allow the hatching of the eggs giving rise to neonate larvae which are then injected onto a nutrient medium in breeding modules. These neonate larvae are then raised in multi-stage growth modules to reach maturity.

[0008] These larvae are finally devitalized and then transformed into a paste rich in nutrients by grinding and heat treatment steps. This paste can then be subjected to additional treatments, finally this paste undergoes a step of extraction of the compounds of interest, in particular the proteins and the oily substances with an installation which is the subject of the present invention. State of the art

[0009] Various solutions are known in the state of the art for separating the compounds of interest from the pastes obtained from larvae.

[0010] Belgian patent application BE1025664 describes a method for separating larvae into a pulp fraction and a liquid fraction, comprising the steps of introducing live larvae into a grinding apparatus while adding water, grinding the larvae by means of counter-rotating screws and separating the ground larval biomass into a pulp fraction and a liquid fraction.

[0011] French patent FR3060947 relates to a method for treating insects comprising separating the cuticles from the soft part of the insects, then separating the soft part of the insects into an oily fraction, a solid fraction and an aqueous fraction. It also describes powders, in particular a powder obtainable by the method for treating insects according to the invention, and the use of these powders in food. This method involves separating the cuticles from the soft part of the insects which is not of interest for a treatment applied to a paste of hygienized larvae.

[0012] We also know the article "Larvae Mediated Valorization of Industrial, Agriculture and Food Wastes: Biorefinery Concept through Bioconversion, Processes, Procedures, and Products" authors Harish Karthikeyan Ravi, Antoine Degrou, Jérôme Costil, Christophe Trespeuch, Farid Chemat and Maryline Abert Vian describing that the larvae pulp mixture naturally comprises three fractions: (a) fraction aqueous (b) lipid fraction and (c) solid fraction. This article describes a treatment method involving enzymatic hydrolysis. The pulp mixture is passed through a "Three-Phase Decanter" to separate the aqueous, lipid and solid fractions. Disadvantages of the Prior Art

[0013] The solutions of the prior art generally implement treatment by enzymatic hydrolysis, which presents a risk factor for industrial processes, since the hydrolysis of water can lead to a risk of explosion if hydrogen and oxygen recombine. On the other hand, the significant use of enzymes considerably increases production costs.

[0014] The solutions of the prior art often require complex installations subject to breakdowns or fouling due to multiple stages of transfer of intermediate compounds from one treatment station to the next by transfer mechanisms which must operate in unfavorable environments (humidity, sticky materials, etc.).

[0015] Many of these solutions also require significant water consumption. Solution provided by the invention

[0016] The invention relates, in its most general sense, to an installation for treating arthropod larvae, and in particular insects and more specifically crushed dipteran larvae, characterized in that the separation of the solid and liquid phases is carried out by a decantation system making it possible to separate three phases: • the solid phase outlet is connected to a flour dryer, • a first liquid outlet feeds a glue water circuit, • a second liquid outlet feeds the oil collection circuit, characterized in that the glue water circuit supplies treatment equipment, in particular heat treatment equipment, for crushed larvae comprising the crushed larvae dilution circuit and / or the glue water evaporator and / or the flour dryer.

[0017] Advantageously, said installation also has the following characteristics: • the outlet of the solid phase is directly connected to a flour dryer by a chute arranged under the outlet of said decantation system making it possible to separate three phases for transfer by gravity; • said flour dryer operates under vacuum; • said flour dryer comprises upstream a sealed transfer airlock formed by two valves opening and closing alternately in order to maintain the vacuum in the flour dryer; • said flour dryer maintained under vacuum is isolated from the downstream part of the process by a sealant lock.; • said flour dryer comprises at the outlet discs fitted with extraction shovels to direct the flour towards the outlet; • said flour dryer is further supplied with concentrate from a glue water evaporator and / or glue water leaving the decantation system allowing three phases to be separated as well as by an antioxidant injection pipe.

[0018] Advantageously, the installation comprises a condenser comprising a plate exchanger for the condensation of the vapors evaporated from the flour during drying and a means for evacuating the condensates.

[0019] Advantageously, said installation also has the following characteristics: • it comprises equipment for concentrating the glue water to 30 to 50% dry matter to form a concentrate reinjected upstream of a flour dryer to be mixed with the cake of the decantation system making it possible to separate three phases and to be dried in said flour dryer; • it comprises a three-way valve controlling the circulation of the oil coming from said second liquid outlet to a recycle in a tank (11) upstream of said decantation system making it possible to separate three phases or to a buffer tank, said valve being controlled by a means for measuring the quality of the oil coming from said decantation system making it possible to separate three phases; • said means for measuring the quality of the oil coming from said decantation system allowing three phases to be separated is a turbidimeter; • it includes thermal regulation means to ensure that the temperature of the crushed larvae paste entering the decantation system allowing three phases to be separated is between 80°C and 95°C. Detailed description of a non-limiting example of embodiment

[0020] Other characteristics and advantages will emerge from the following description of the invention, a description given by way of example only, referring to the appended drawings in which:

[0021] [Fig-1] [Fig.l] represents the diagram of the dough preparation treatments subject to separation treatments according to the invention;

[0022] [Fig.2] [Fig.2] represents the diagram of the separation treatments according to the invention;

[0023] [Fig.3] [Fig.3] represents the schematic view of a three-phase decanter used for separation according to the invention;

[0024] [Fig.4] [Fig.4] represents the schematic view of a hammer mill according to the invention. General principle of the invention

[0025] The present invention relates to the valorization of the compounds of interest of a paste of ground larvae obtained after application to arthropod larvae, preferably insects and more particularly diptera, in particular black soldier flies, of treatments for devitalizing the live larvae, and of sanitizing this paste when the process chosen for the devitalization is carried out at temperatures too low to ensure the destruction of all the bacteria. The sanitizing of this paste can be carried out in particular in a sanitizing heat exchanger whose function is to raise the product to the target temperature of the heat treatment, then in a chamber which maintains the product at the correct temperature for the desired duration.

[0026] The treatment of this paste, the subject of the present invention, consists in particular of separating it into three phases: a solid phase, a heavy liquid phase and a light liquid phase. Pretreatment of live mature larvae

[0027] Prior to this separation which is the subject of the present invention, the mature larvae are subjected to one or more pretreatments consisting of devitalizing them by a heat treatment in an aqueous medium, grinding the devitalized larvae and mixing them with water to prepare a nutritive paste, then sanitizing this paste.

[0028] Before the devitalization step, the larvae are usually separated from the frass (consisting of a mixture of larval excrement and residues of the uneaten, dried and fermented substrate) via two granulometric separation steps. The first step is carried out using a trampoline sieve which separates the live larvae from the powdered frass. The second step is carried out using a circular screen which separates the live larvae from any agglomerated frass pellets.

[0029] The larvae fall by gravity into a parallelepiped tank, which avoids the use of complex installations requiring the use of pumps or motorized movement systems. The larvae are mixed with water in a controlled proportion depending on the flow rate of larvae measured on the weighing belt. Water is used for several reasons. • Firstly, water serves as a transport vector to make it easier to handle and transfer the larvae by pumping. • Water also serves as a thermal vector to thermally devitalize the larvae. • Water is also used to finish cleaning the larvae and constitutes a third purification step. Indeed, the larvae are relatively moist on the surface and "grains" of frass can end up stuck to their surfaces. In this case, the sieving step using the trampoline sieve is not effective because this stuck frass remains attached to the larvae. In water, the frass can detach and pass into the aqueous phase.

[0030] The live larvae and the residual frass are immersed in a tank containing hot water. The contents of this tank, the mixture of larvae, water and residual frass, are transferred into an exchanger (1) using a membrane pump to bring the mixture to a temperature between 55° and 95°C (preferably between 75 and 80°C) in order to devitalize the larvae. The mixture of devitalized larvae, water and residual frass is then poured onto a sieve-drip tray (2) separating the devitalized larvae and the charged effluents (water and residual frass). The larvae are transferred to a grinder (3). The loaded effluents are discharged into the dirty compartment of a settling tank (4) separating the frass which is transferred to a frass press (5) then to frass recovery equipment (10).The purified water obtained at the outlet of the frass press can then be reinjected into the clean compartment of the settling tank to concentrate the residual frass in the dirty compartment. Clean water is also drawn from the clean compartment of the settling tank to be reinjected into the mixing tank.

[0031] The devitalized and cleaned larvae from the draining screen (2) are transferred into two grinders in series (3) using an eccentric rotor pump. Transfer of devitalized larvae paste

[0032] An eccentric rotor pump (7) transfers the crushed larvae from the 4 m3 launch tank (6), fed by the crushers (3), through a heat exchanger (8) then a chamber (9) and a cooler (10) to a buffer tank (11) with a capacity of 15 m3 for example. Dilution of larvae

[0033] Just upstream of the second of the two grinders in series (3), water is introduced to dilute the larvae. The larvae flow rate is measured at the inlet of the processing zone, upstream of the water addition, by an electromagnetic flow meter (13). The water flow rate is also measured by an electromagnetic flow meter (16). A dilution ratio is maintained.

[0034] Depending on the actual flow rate of crushed larvae, the water flow rate is adjusted to maintain the target dilution ratio (between 20 and 50%). The dilution ratio is chosen in relation to the quality of the phase separation in the three-phase separator also called three-phase decanter (12) and pressure losses in pipes and equipment. The ratio can be configured by the operator.

[0035] The water added to the larvae comes from two different sources. • On the one hand, the water used is glue water recovered from the outlet of the three-phase decanter (12). The temperature of the glue water is above 70°C. The glue water that is added comes directly from the three-phase decanter and is therefore part of the same production batch. • On the other hand, the water used comes from an ECP network (Process Hot Water, a network distributing hot water throughout the industrial site from softened water heating). The temperature of the ECP is 55°C.

[0036] Two pilot-controlled valves (17, 18) control the respective flow rates of these two sources to optimize energy consumption. When the line is started, it is the water from the ECP network that is added to the larvae upstream of the second grinder (3). The switch from the ECP network to the glue water produced by the three-phase decanter (12) takes place at the end of the line start-up.

[0037] The use of the glue water produced by the three-phase decanter (12) allows: • energy optimization by mixing hot water at around 70°C with the crushed larvae; • optimization of water consumption. Using ECP, water is added to the system, whereas using glue water, no additional water is introduced into the system, which reduces the amount of glue water produced. This also represents a significant energy optimization since the glue water is evaporated and then dried. Separation of the crushed larvae paste

[0038] After the various treatments allowing the conversion of live larvae to a larval paste cleaned of frass residues and hygienized, the substances of interest present in this paste are separated.

[0039] The main separation step is carried out via a three-phase centrifugal decanter (12) composed of a rotating bowl (30) in the center of which a screw (31) is also rotating. It makes it possible to mechanically separate the paste formed from crushed larvae and water introduced via a feed pipe (35) from the bowl (30), in 3 phases. • Phase 1: the defatted cake, which is still at approximately 50% moisture. It is sent to a vacuum disc dryer and is discharged by gravity via a first outlet (32). • Phase 2: the glue water, which is a liquid loaded with soluble proteins, which is evacuated through a pipe (33) into a recovery tank itself connected to a lifting pump. • Phase 3: the oil, very pure (<1% impurities) which flows from the bowl (30) and which is sent to the packaging via a conduit (34).

[0040] The temperature at the inlet of the three-phase decanter (12) is at least 80°C for efficient separation of the three phases and preferably less than 95°C.

[0041] The speed of the bowl and the differential speed, i.e. the difference between the speed of the bowl (30) and that of the screw (31), are adjusted to aim for a yield / purity compromise and: • maximize protein recovery in the cake and in the glue water; • maximize protein purity to have the best protein level to allow good degreasing of the cake and glue water; • secondarily, limit moisture in the cake to reduce energy costs of drying the cake.

[0042] One adjustment solution consists of starting by maximizing the speed of the bowl (30) and adjusting the differential speed to find the best purity / yield compromise.

[0043] Another adjustment to optimize the separation between the oil and the glue water and therefore minimize the amount of water in the oil consists of manually adjusting a turbine on the three-phase decanter to adjust the oil / water interface on the internal separation disc of the machine.

[0044] The parameters are preset at start-up and can then be controlled according to the quality analyses of the products separated by the three outlets (32 to 34) of the three-phase decanter, in particular according to the humidity and fat content. Flour processing

[0045] The term flour refers to the cake from the three-phase decanter to which glue water or the concentrate from the evaporation of the glue water can be added, the whole being then dried and ground.

[0046] The cake at the outlet of the three-phase decanter (12) falls by gravity into a chute (62) located between the solids outlet of the three-phase decanter and the feed of the dryer (60). Since the cake is a product that is difficult to handle and the handling equipment is difficult to clean, the gravity method makes it possible to ensure the transfer between the decanter (12) in an efficient and economical manner.

[0047] The flour dryer (60) operates under vacuum. Between the three-phase decanter (12) and the dryer (60), two valves (61) open and close alternately in order to maintain the vacuum in the dryer (60). These two valves (61) are never open at the same time and form a sealed transfer airlock. Two other products also arrive in this chute (62): • the concentrate leaving the evaporator (50) or the glue water leaving the three-phase decanter (12); • an injection of antioxidant.

[0048] Adding glue water or glue water concentrate is not essential to produce flour, but it does allow for better quality flour. Adding antioxidants to flour

[0049] The antioxidant is added before drying the flour in order to ensure good preservation of the flour. Passing through the dryer (60) allows the antioxidant to be well mixed with the flour.

[0050] The antioxidant concentration in the flour after drying is set at 800 ppm. An antioxidant delivery pump pumps the antioxidant into an antioxidant canister to send it to the chute (62) between the three-phase decanter (12) and the dryer (60). The flow rate of the antioxidant pump is adjusted by a controller according to the defined concentration and the flow rate at the inlet of the dryer (60). The flow rate of glue water and the flow rate of concentrate are measured by flow meters. The flow rate of cake is estimated by the controller according to the flow rate of ground larvae paste at the inlet of the three-phase decanter (12). Drying the flour

[0051] The cake at the outlet of the three-phase decanter (12) still has 50% moisture. In the same way, the glue water concentrate is also between 50 and 70% moisture. A drying step provided by a vacuum disc dryer (60), comprising a rotor on which discs are present, rotates in a closed enclosure. These discs have shovels described below.

[0052] The steam from the network circulates through the discs to heat them. The steam condenses and the steam condensates at the outlet of the dryer are sent to the boiler via the condensate network. There is no contact between the steam and the flour.

[0053] The flour circulates between the discs. Scoops located on the discs allow the flour to be moved at a higher or lower speed depending on the shape of the scoops.

[0054] The humidity of the flour decreases as the product advances through the dryer. The humidity at the inlet is approximately between 50 and 60%, at the outlet the humidity of the flour is between 5 and 7%. The speed of the discs is continuously monitored.

[0055] A sample intake is located at the dryer outlet (60). Flour samples are taken by the operator every 10 or 20 minutes for off-line moisture analysis on a desiccant scale. When the moisture decreases below 10%, samples are taken every 5 minutes. Alternatively, a moisture measurement sensor located in the dryer at the outlet allows to continuously monitor humidity. Flour extraction can then be done automatically according to humidity.

[0056] Once the target humidity of between 5% and 7% is reached, the operator opens the valve located on the flour outlet of the dryer (60). The shape of the scoops located on the discs at the outlet allows the flour to be directed towards the outlet located on the side of the dryer. The scoops are wide and flat, perpendicular to the discs in order to raise the flour from the bottom of the dryer towards the outlet.

[0057] Four types of shovels are operated in the dryer, neutral for mixing, positive for advancing the flour, negative to improve drying and extraction shovels to push and extract the flour from the flour dryer.

[0058] The evaporated vapors from the flour exit at the top of the dryer (60). They are condensed in a plate exchanger with cold water. This water is cooled in an air cooler located on the roof of the processing building. At the outlet of the condenser, the condensates are separated from the non-condensed vapors and reused or sent to the wastewater.

[0059] The non-condensed vapors are sucked out by a vacuum pump which creates a vacuum in the dryer. The vacuum is 400 mbar. At this pressure, the boiling point of water is 75°C. This allows for a relatively low temperature in the dryer in order to preserve the qualities of the flour, and in particular to avoid degrading digestibility.

[0060] The dryer (60) is isolated from the upstream and downstream equipment which is not under vacuum. Upstream of the dryer (60), the isolation is done by the 2 valves which cannot be opened simultaneously. Downstream, a lock provides sealing. Cooling the flour

[0061] The dryer outlet is by gravity and not by a screw as in the prior art, to limit the risk of condensation and bacterial contamination, as well as the risk of fouling.

[0062] The flour leaving the dryer (60) falls into a lock and then into a heat-insulated pneumatic conveyor (63) which carries it to the cooler (64). The transfer at the dryer outlet is done by pneumatic conveyor (63) and not by a screw as in the prior art, to limit the risk of condensation and bacterial contamination. The flour is cooled to room temperature plus 10°C.

[0063] Ambient air is drawn around the perimeter of the cooler (64) and circulates counter-currently through the flour layer. The hot air is filtered and discharged outside the building.

[0064] When a layer of flour is cooled to the target temperature, valves located under the layer of flour open automatically so that the flour flows by gravity towards the grinder (65) located under the cooler. Crusher structure (65)

[0065] The flour is ground in a hammer mill (65) illustrated in [Fig.4]. Hammers (70) located on a rotor strike the flour through a grid (71) of 2mm mesh size for example. The particle size of the flour leaving the mill is therefore 2mm in this example.

[0066] Magnets are installed at the feed of the crusher in order to protect the crusher from possible metallic foreign bodies which would damage it. After each production run, the operator can dismantle these magnets and clean them, then put them back in place. This dismantling and cleaning of the magnets allows: • to assess whether metallic materials have been stopped and, if so, to quickly identify the causes upstream of the process; • to prevent the magnet from becoming “full” and losing its effectiveness.

[0067] The fan (72) of the grinder allows the flour to be conveyed by pneumatic transport to the 3 m3 buffer hopper (66) located downstream. Upstream of this hopper, on the piping, a second magnet is installed in order to capture any metal particles generated during grinding. Flour packaging

[0068] The flour is packaged in 500 kg “big-bag” (trade name) type containers (67), suitable for food contact. A filling station is located under the 3 m3 buffer hopper (66). This buffer hopper (66) allows the flour to be stored while the operator changes containers (67). The filling station is on load cells, which are wired to the machine.

[0069] The operator first installs an empty container (67) on the filling station. He starts inflating the container (67). Once inflation is complete, the operator presses another button to extend the container (67), then a final button which sends a signal to the central controller indicating that the container (67) is ready to receive the flour.

[0070] The sequence for filling the container (67) is then launched automatically. The target weight setting entered into the machine is 500 kg. The empty container (67) is tared, then the lock located at the bottom of the buffer hopper and the vibrating bottom of the hopper start. Filling stops when the target weight is reached (stopping the lock and the vibrating bottom). The operator retrieves the container (67) and transports it to the finished product storage area. He can then install a new container (67) if there is still flour in the buffer hopper (66).

[0071] It is also proposed to store the flour in bulk in silos and market it in bulk trucks. Glue water management

[0072] The glue water produced by the three-phase decanter (12) is composed of water contained in the larvae, water possibly added in the process (residue from draining during slaughter and / or dilution of the larvae with hot process water), but also a little fat and dissolved solid.

[0073] The recovery of glue water as a dilution means is targeted here. The advantages are mainly to reduce the consumption of dilution water and to save energy because it is not necessary to heat it to 80°C.

[0074] Since separation by decantation is not perfect, some of the solids and fats end up in the fining water. The solids that pass into the fining water are often good quality, highly soluble proteins. There is therefore a strong interest in reusing them to increase the overall yield of the line and improve the quality of the flour.

[0075] As described above, a portion of the glue water is recycled upstream of the separation to optimize the separation as well as minimize the consumption of hot water.

[0076] Another part of the glue water can also be directly introduced in small quantities into the dryer to be dried in combination with the cake. This step is optional and not necessary for the proper running of the process.

[0077] Generally, the glue water is fed to a two-effect evaporator (50) (i.e. with two evaporation stages in two specific plate exchangers). The evaporator (50) allows a change from a dry matter percentage of 5% to between 30% and 50%. In the first effect, the glue water is pre-concentrated. Then in the second effect, the concentration reaches the target value. The concentration is estimated via a density measurement, used as an image of the quantity of dry matter. Energy optimization of evaporation

[0078] To ensure the concentration of the glue water, a significant amount of water is evaporated. Energy must therefore be provided.

[0079] The evaporator (50) has been designed to operate with two possible energy sources: • live steam; • the recovery of vapors (i.e. the water evaporated from the glue water), mechanically recompressed to provide them with more energy.

[0080] Mechanical recompression of vapors is possible as soon as the production of vapors by evaporation is higher than the minimum load point ("turndown") of the compressor called MVR (Mechanical Vapor Recovery). Before this point, live steam is used to heat the 1st effect, and the vapors extracted from the 1st effect heat the 2nd effect. Beyond this point, the vapors from the 1st and 2nd effects are recovered and recompressed to provide the required energy. In MVR mode, no live steam is used except when the evaporator is started (50).

[0081] The switch between MVR mode and live steam mode is done with a set of rotating eyeglass joints to modify the steam and steam circuits. The switch is therefore necessarily done outside of production. These two modes allow the evaporator (50) to operate over a wide range of glue water flow rates. Optimization of product quality

[0082] In order to limit the time / temperature couple applied to the glue water, the evaporator (50) is placed under vacuum so that evaporation occurs at a temperature below 100°C. A vacuum pump makes it possible to maintain a vacuum of 400 mbar in the exchangers to ensure a temperature of approximately 75°C during the process. Recovery of the concentrate

[0083] After evaporation, the glue water is concentrated to approximately 30 to 50% dry matter to form a concentrate. The concentrate is drawn off by a pump (51) from the evaporator concentrate storage tank to the airlock at the dryer feed. The concentrate is transferred only when the three-phase decanter is in operation. Since the concentrate is a sticky product, it cannot be dried alone in the disc dryer at the risk of fouling the discs. It is mixed with the cake at a maximum concentration of 20% relative to the cake flow rate to avoid fouling. Oil production

[0084] The oil leaving the three-phase decanter flows from the bowl (30) into the conduit (34) by gravity to a small 100L buffer tank (40) from where it is sucked to be transferred by a pump (41) to a storage tank (44) with a capacity of 30m3. It is then packaged in flexible or rigid-shell containers (47) of the IBC (Intermediate Bulk Container) type or shipped in a tanker truck supplied by an eccentric rotor pump. Oil quality

[0085] At the discharge of the pump (41), a turbidity probe ensures that the oil sent to the storage tank (44) is pure. This probe measures the turbidity, i.e. the opacity, which makes it possible to obtain a humidity value. When the turbidimeter detects a humidity level above a threshold between 0.3% and 1%, then the oil is recycled into the tank (11) located upstream of the three-phase decanter (12).

[0086] The water-laden oil is recycled upstream of the three-phase decanter, it is mixed with the crushed larvae paste in the stirred tank (11) to be separated again in the decanter.

[0087] A three-way valve (43) controlled by the turbidimeter (42) controls the transfer of the oil either to the storage tank (44) or to the oil recycling tank (11).

[0088] When the line starts up, the 3-way valve (43) is open in the oil recycling position towards the tank (11) and closed towards storage (44): before stabilization of the three-phase decanter (12), the oil is loaded with water, therefore recycled via the buffer tank (11) and not sent to storage towards the tank (44).

[0089] When the oil is pure, the 3-way valve (43) closes towards the tank (11) and opens towards the oil storage tank (44).

[0090] At the supply of the storage tank (44), or downstream of the storage tank, at the level of packaging in IBC or tanker truck, a magnet (46) and a filter make it possible to trap any metallic foreign bodies.

[0091] At the end of production, an injection of compressed air is made at the discharge of the pump (41). This allows the oil to be pushed towards the storage tank (44) to empty the pipes. Maintaining oil temperature

[0092] The buffer tank (40) located at the outlet of the three-phase decanter (12) is heat-insulated. The oil pipes are all electrically traced and heat-insulated to ensure that the oil remains liquid in the pipes and does not solidify. The oil solidifies at a relatively low temperature, of the order of 30°C.

[0093] The storage tank (44) is maintained at temperature by a double jacket in which hot water circulates without contact with the product. Maintaining the temperature prevents the oil from solidifying in the tank (44).

[0094] A hot water loop circulates in the double jacket of the tank. The water has a temperature of 58°C, it is heated in a plate exchanger using water at 60°C and circulates continuously in the circuit via a pump. Oil conditioning

[0095] A conditioning pump (45) draws the oil from the 30 m3 storage tank (44) to transfer it to a 1 m3 IBC container (47). The IBC containers used for conditioning the oil are suitable for food contact.

[0096] An operator places an empty IBC container on a pallet truck with integrated scale, tares it, then places a hose connected to the discharge of the conditioning pump (45) in this container.

[0097] The conditioning pump (45) operates at a flow rate of 2m3 / h, so filling an IBC container (47) takes 30 minutes. The first operator checks the weight of the IBC container (47) on the scale. It is also possible to use a second pump drawing from the storage tank and discharging to a tanker truck. A hose is connected to the discharge of this pump to the tanker truck parked outside the building. Adding antioxidant to the oil

[0098] To avoid the appearance of a rancid odor or taste and to ensure good preservation of the oil, an antioxidant is added to the IBC (47) of oil, in particular a tocopherol-type antioxidant.

[0099] The antioxidant concentration in the oil is set at 800 ppm. When filling the container with oil begins, the operator validates on the supervision the total quantity of antioxidant to be added for a container filled with oil. The antioxidant pump then automatically pumps the antioxidant from the can to the container simultaneously with filling the container with oil, to promote mixing and homogeneity of the finished product.

[0100] Alternatively the oil is sent to the IBC packaging. Once finished, the oil is weighed in the packaging and the antioxidant is added to the packaging directly according to the quantity of oil weighed and the desired concentration. The whole is then stirred to mix the antioxidant.

[0101] Similarly, the antioxidant is added to the oil line in the case of tanker truck filling.

Claims

Claims

1. - Installation for treating arthropod larvae, and in particular insects and more specifically crushed dipteran larvae, comprising a decantation system (12) for separating the solid and liquid phases, characterized in that the separation of the solid and liquid phases is carried out by a decantation system (12) having three outlets: • the solid phase outlet is connected to a flour dryer (60) • a first liquid outlet feeds a glue water circuit, • a second liquid outlet feeds the oil collection circuit, characterized in that said glue water circuit feeds equipment for treating crushed larvae comprising the crushed larvae dilution circuit.

2. - Installation for treating crushed larvae according to claim 1 characterized in that said glue water circuit further comprises a glue water evaporator.

3. - Installation for treating crushed larvae according to claim 1 characterized in that said glue water circuit further comprises said flour dryer.

4. - Installation for treating crushed larvae according to claim 1 characterized in that the outlet of the solid phase is directly connected to a flour dryer (60) by a chute (62) arranged under the outlet of said decantation system making it possible to separate three phases (12) for transfer by gravity.

5. - Installation for treating crushed larvae according to claim 1 characterized in that said flour dryer (60) is of the type operating under vacuum.

6. - Installation for treating crushed larvae according to the preceding claim, characterized in that said flour dryer (60) comprises upstream a sealed transfer airlock formed by two valves (61) opening and closing alternately in order to maintain the vacuum in the flour dryer (60).

7. - Installation for processing crushed larvae according to claim 5 characterized in that it comprises a sealed isolation lock of said flour dryer (60) maintained under vacuum relative to the downstream of the process.

8. - Installation for treating crushed larvae according to claim 1 characterized in that said flour dryer (60) comprises at the outlet discs equipped with extraction shovels to direct the flour towards the outlet.

9. - Installation for treating crushed larvae according to claim 1 characterized in that said flour dryer (60) is connected to an evaporator (50) of glue water and / or glue water leaving said decantation system (12) and to an antioxidant injection conduit.

10. - Installation for treating crushed larvae according to claim 1, characterized in that it comprises a condenser comprising a plate exchanger for the condensation of the vapors evaporated from the flour during drying and a means for discharging the condensates.

11. - Installation for treating crushed larvae according to claim 1 characterized in that it comprises equipment for concentrating the glue water to 30 to 50% dry matter to form a concentrate reinjected upstream of a flour dryer and a means for mixing said concentrate with the cake of the decantation system (12).

12. - Installation for treating crushed larvae according to claim 1 characterized in that it comprises a three-way valve (43) whose inlet is connected to said second liquid outlet and one of the outlets is connected to a tank (11) upstream of said decantation system (12) and another outlet is connected to a buffer tank (44), said installation further comprising a means for measuring the quality of the oil coming from said decantation system (12) delivering a signal for controlling said valve (43).

13. - Installation for treating crushed larvae according to the preceding claim, characterized in that said means for measuring the quality of the oil coming from said decantation system making it possible to separate three phases (12) is a turbidimeter.

14. - Installation for treating crushed larvae according to claim 1 characterized in that it comprises thermal regulation means to ensure that the temperature of the larvae paste crushed at the inlet of the decantation system allowing the separation of three phases (12) is between 80°C and 95°C.

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