FR3007121A1 - CALORIES TRANSFER INSTALLATION AND METHOD - Google Patents

Abstract

The invention relates to an installation (1) comprising a rack (2) containing biodegradable material and having a first floor (20), and a first circuit (4) for fluid circulation comprising a drain (41) communicating with the inside the bin (2), and an extraction duct (42), means (43) for forced circulation of fluid from the drain portion (41) to the extraction duct portion (42). Said installation comprises a second floor (80) and a second fluid circulation circuit (5) comprising a blowing duct (51), and a drain (52) communicating with the top face of said second floor (80), means (59) for forced circulation of fluid from the blow duct portion (51) to the drain portion (52), and a heat exchanger (6) for heat exchange between the flow of fluid flowing through the extraction duct (42) and the flow of fluid flowing through the blowing duct (51).

Description

The present invention generally relates to the transfer of calories from the biodegradability of a material. It is known from the state of the art an installation according to which a hot gas stream is extracted from a material contained in a composting bin to transfer calories to another stream entering said bin. Said material forms a porous assembly in the air, such as a pile of waste or a mixture of waste and structuring elements.

However, it is observed that such a configuration of the installation does not allow efficient heating and / or drying of the material. Thus, in the case of a material formed of household waste to incinerate, such an installation does not effectively reduce the moisture content of the material. However, the reduction of the moisture content makes it possible to increase the lower heating value (ICP) of this material and thus to increase the recoverable energy, by incineration, in the form of electricity or heat. Such an installation is also not usable for simple heating and / or drying, without or with little transformation, of a material for example agricultural, such as grains, since said material undergoes in the compost bin a phase of composting. The present invention aims to propose a new installation for improving the heating and / or drying of a material.

To this end, the subject of the invention is a calorie transfer installation comprising: a bin, capable of containing a biodegradable organic material, having a first floor, such as a concrete slab, a first circulation circuit of fluid comprising: - a drain portion, perforated along its length, located under or flush with the face of the first floor facing the interior of the rack and at least a portion of the orifices communicating with the interior of the rack, and - a part, called extraction duct, which extends said drain, - means for forced circulation of fluid from the drain portion to the extraction duct portion, such as a fan, - a second floor, such as a concrete slab, having a face, said top face, adapted to receive a material to be heated and / or drying, - a second fluid circulation circuit comprising a portion, called a blow duct e, and a drain portion, perforated along its length, extending said blow duct and located under or flush with the top face of the second floor, at least a portion of the orifices of said drain communicating with the top face of said second floor - Means for forced circulation of fluid from the blow duct portion, such as a fan, to the drain portion of the second circuit, - a heat exchanger for heat exchange between the circulating fluid flow in the extraction duct and the flow of fluid flowing in the blowing duct. Aerobic biodegradation of an organic material generates a rise in temperature of the material. The biodegradable material may be composted or bio-dried. Bio-drying refers to the use of heat produced by the biological consumption of at least a portion of the biodegradable organic material to dry the material. By composting is meant the biological removal of at least a portion of the biodegradable organic matter to produce a stable material, i.e., lower degradation kinetics, called compost. Such an installation according to the invention makes it possible to efficiently transfer calories from an organic material contained in a bin, for example a composting or biodrying bin, and disposed on the first floor, to another material, possibly contained in another bin, disposed on the second floor for heating and / or drying.

Said other material may be organic or otherwise and form a porous assembly in the air. Forced circulation of fluid allows the drain portion of the first circuit to be depressed, which allows air outside the rack to be drawn through the bin material to form a gaseous effluent conveyed through the drain portion, to the heat exchanger. Said gaseous effluent can thus yield its calories to the flow of fluid passing through the second circuit to be diffused by the drain portion, at an excess pressure, of the second circuit, through the material to be heated and / or dried. In addition, the forced ventilation of the rack by suction at the portion of the drain duct makes it possible to recover a gaseous effluent having a large amount of heat. Depending on the biodegradation conditions of the material contained in the rack subjected to forced aeration, such as for example the rate of aeration, a significant part of the heat produced is found in sensitive and above all latent form in the outgoing gaseous effluent. of the rack, whose temperature is high and which is concentrated in water vapor. The application of a forced aeration, contrary to a natural aeration, makes it possible to better control the supply of dioxygen (02) inside the rack, to increase it, and moreover to increase the transfer of the heat produced in favor of heat in sensitive form and especially latent in the gaseous effluent leaving the bin. The cooling of the gaseous effluent leaving the trap by circulation through the exchanger causes the condensation of the water vapor which it contains, which is accompanied by a release of heat which can be used for, via the heating the gaseous effluent flowing in the second circuit, heating and / or drying the material located above the drain portion of the second circuit and separate from the material contained in the rack.

In particular, in the case where the material on the second floor is intended for incineration, the intake of calories from the biodegradation of the material on the first floor, this material to incinerate, allows to increase the amount of energy produced and therefore recoverable during the incineration of this material. In the case where the material deposited on the second floor is a material, for example grains, that it is simply desired to dry or heat, said installation allows this simple drying or heating without transformation of the composting type of this material, or in a limited way, since the biodegraded material from which the calories are taken is distinct from the material to be dried. According to an advantageous characteristic of the invention, the outlet of the extraction duct and the inlet of said blowing duct are distinct.

The use of an extraction duct and a blowing duct devoid of fluid communication between them makes it possible to evacuate the flow of fluid formed by the gaseous effluent, resulting from the material contained in the rack, outside the the installation or in a treatment unit for olfactory reasons, and to introduce a flow of air, weakly loaded with moisture and heated by the exchanger, into the blowing duct with a view to its blowing through the disposed material on the second floor. Thus the flow of fluid flowing in the second circuit and intended to be blown through the material disposed on the second floor, does not have too much moisture compared to the case where it would be the fluid from the extraction duct that would be broadcast in the material disposed on the second floor. According to an advantageous characteristic of the invention, said first circulation circuit associated with the rack is provided with liquid discharge means 30 positioned at least downstream of the drain portion. According to an advantageous characteristic of the invention, the wall of said first circulation circuit which extends from the draining portion includes up to the exchanger and / or the wall of said second circulation circuit which extends from the heat exchanger up to and including the drain portion, has a thermal conductivity in W / m / ° K of less than or equal to 0.5.

According to an advantageous characteristic of the invention, the flow of fluid flowing through the extraction duct and that flowing through the blowing duct circulate in the heat exchanger in opposite directions from one another.

According to an advantageous characteristic of the invention, said rack has an air inlet at the top of the rack. In the at least partially filled state of said bin, the air inlet is located above the biodegradable material.

Of course, it is expected that the rack has no physical wall on the loading side of the rack and thus the air inlet is not only from above but also laterally.

According to a particular embodiment of the invention, the installation comprises another rack capable of containing said material to be dried and / or heated, said second floor forming the bottom of said other rack, said at least part of the orifices of said drain which communicates with the top face of said second floor, opening into said other rack.

The invention also relates to a method of calorie transfer using an installation as described above, between a material contained in said rack and a material disposed on said second floor, characterized in that: - it generates a forced circulation of air from the portion of the first flow circuit forming a drain towards the extraction conduit portion, so that, by suction at the drain, the air, outside the rack, passes through the material present in the rack forming a gaseous effluent of different composition of the air entering said bin and of higher temperature, said gaseous effluent passing through the extraction duct and passing through the exchanger, - it generates a forced circulation of air from the part of the second circulation circuit forming a blow duct towards the drain portion of said second circulation circuit, so that air passes through the exchanger, to recover er calories of the fluid flowing in the extraction duct, and passes through the blowing duct to be diffused by the orifices of the drain in the material disposed on said second floor.

The forced circulation of air through the biodegradable material of the rack allows to supply in oxygen the microorganisms contained in the material, which will consume oxygen (02) and a part of the biodegradable fraction of the material, and produce carbon dioxide. carbon (CO2). This consumption generates a heat production which causes a rise in the temperature of the material and the evaporation of a part of the water contained in this material. Advantageously, said method is used to dry the material disposed on said floor. Said method can also be used to heat said material placed on said second floor. According to a particular embodiment of the process according to the invention, the material placed on the second floor is removed, and the material present in the bin is moved onto the second floor, a new material being introduced into said bin. Such an embodiment makes it possible to heat and / or dry the material previously present in said bin and to promote a new biodegradable organic material in said bin. Preferably, this transfer from one floor to the other is carried out after biodegradation, for example by composting or by biodrying, of the material initially present in the bin.

The invention will be better understood on reading the following description of exemplary embodiments, with reference to the figure which is a perspective view of an installation according to the invention.

With reference to the figure and as recalled above, the invention relates to an installation 1 comprising a calorie transfer installation which comprises a rack 2 at least partially filled with a biodegradable organic material. In the example illustrated in the figure, said bin 2 is a compost bin 2 in the sense that the biodegradable organic material is subjected to composting. Alternatively, the biodegradable organic material can be bio-dried and the description thus also applies to the case of a rack 2 containing a material subjected to a biodrying.

Said compost bin 2 has a first floor 20, such as a concrete slab. The walls of the locker are for example concrete or wood. Preferably, said floor is a concrete slab on which the material contained in the composting rack 2 rests. Advantageously, said floor is thermally insulated.

Said at least one composting bin 2 is provided with a fluid circulation circuit 4 which comprises a portion 41 forming a drain, perforated along its length, located under or flush with the inner face of the floor 20 of the rack.

Preferably, the portion 41 forming a drain is embedded in the floor slab 20 of the compost bin 2 and the upper surface of said drain is flush with the upper face of the floor 20 so that at least a portion of the orifices, preferably all said orifices, said drain 41 communicates (s) with the interior of the compost bin 2. Such an arrangement of each drain 41 makes it possible to avoid damaging the drain when the bin is scraped during handling operations of the material to be composted or composted, while ensuring good fluid communication between the drain and the interior of the container. compost bin. Preferably, the material is loaded in the bin 2 so that all the orifices of each drain 41 is covered with this material.

In the example illustrated in the figures, said drain portion 41 comprises a plurality of drainage ducts parallel to each other and interconnected by a manifold 412 extended by an extraction duct 42. Said extraction duct is not drilled. on its peripheral wall. Said extraction duct 42 opens into a heat exchanger 6. In particular, said heat exchanger 6 comprises a heat transfer circuit whose input is connected to the extraction duct 42 and whose output is connected to a duct. discharge which can be considered as the output of the pipe 42 of extraction downstream of the exchanger. As detailed below, said heat exchanger 6 also comprises a heat recovery circuit whose input makes it possible to take a flow of fluid to be heated, and the outlet of which is connected to a blowing duct 51. In the heat exchanger , the recovery circuit is arranged with the transfer circuit to allow a calorie transfer of the fluid flow from the extraction duct 42 to the flow of fluid for passing through the blowing duct 51 as detailed below.

Said circulation circuit 4 is provided with a fan 43 for the forced circulation of fluid from the drain portion 41 to the extraction duct portion 42.

The installation also includes a second floor 80, such as a concrete slab, separate from said first floor, on which a material to be heated or dried can be deposited. Said second floor 80 may be surmounted by walls making it possible to form a rack containing said material to be heated or dried, of a structure similar to that of the composting rack 2. In other words, said heating or drying material which rests on the second floor 80 may be contained in another separate bin of the compost bin 2. The material placed on the second floor is a porous material in the air, such as a pile of waste and / or a maturing or composted mixture. The material laid on the first floor is a fresh non-composted or unstabilized material, i.e. with a residual of biodegradable material, to produce heat.

Separate floors are understood to mean that the carrying surface of the material to be heated or dried is distinct from that on which the material from which the calories are to be taken is based. In other words, the material to be heated or dried that rests on the second floor is distinct from that which rests on the first floor. However, the first and second floors can be formed in one piece. Preferably, the material present on each floor covers the drain orifices opening at the level of the top face of said floor.

The installation also comprises a second fluid circulation circuit 5 comprising a portion 51 not perforated along its length, called a blow duct, and a portion 52 forming a drain, perforated along its length, extending said blowing duct 51 and located under or flush with the face of the second floor 80. At least a portion of the orifices of said drain 52 communicate with the top face of said second floor 80 to allow the flow of fluid exiting the drain 52 to be diffused through said material resting on it. second floor 80. In the example illustrated in the figure said drain portion 52 is formed of a plurality of parallel drains connected to the blow duct 51 by a distributor 53. Said second circulation circuit 5 is provided with a fan 59 for the forced circulation of fluid from the blow duct portion 51 to the drain portion 52. The blow duct 51 is connected to the exchanger 6 so as to allow a heat exchange between the flow of fluid flowing through the extraction duct 42 and the flow of fluid flowing through the blowing duct 51. The inlet of the heat exchanger heat which makes it possible to supply the exchanger with a flow of fluid to be heated can be considered as the inlet of the blow duct 51. Said heat exchanger 6 is for example a plate heat exchanger. The output of the extraction duct 42 corresponding to the output of the transfer circuit of the exchanger 6 and the inlet of said blowing duct 51 corresponding to the inlet of the recovery circuit of the exchanger 6 are distinct. In other words, the outlet of the extraction duct 42 does not communicate with the inlet of the blowing duct 51.

Said entry and / or said exit may open in the confined atmosphere or not. The exit of the extraction duct 42 can also lead into a gas treatment unit. In the example illustrated in the figures, the fan 43 is located downstream of the heat exchanger 6, with reference to the direction of flow of the fluid in the extraction duct 42. Similarly, the fan 59 associated with the blowing duct 51 is located downstream of the heat exchanger 6, with reference to the direction of flow of the fluid in said blowing duct 51.

Advantageously, each circuit 4, 5 is an open circuit. For simplicity, the description is made below for a compost bin, but of course applies to a plurality of composting bins provided with several first circulation circuits. Similarly, the plant may be provided with a plurality of second circulation circuits arranged to recover calories from the first circulation circuits and transfer them to one or a plurality of heaps of material to be heated or dried. In this case, the circulation circuits 4 are supplied by the air flow (s) coming out of the rack (s) and, depending on the age of the composting material in each of the compartments as well as the characteristics of this material (biodegradability ), the withdrawal of fluid through the circulation circuits 4 may be different from one rack to another. Thus, advantageously, the withdrawal rate at each composting bin is adjustable by means of a valve, and preferably a flowmeter, installed on each pipe 42 leaving each bin. similarly, it can be provided that the installation comprises a plurality of circulation circuits 5 coupled with the circulation circuits 4 by one or more exchangers. It can be provided to associate an exhaust fan to each circulation circuit 4 or an exhaust fan common to said circulation circuits 4. Similarly, provision may be made to associate a blower with each circulation circuit or a blower common to said circulation circuits. Different combinations of circuits 4, 5 of circulation are possible. Preferably, the or each fan may be configured to allow regulation of the fluid flow that it extracts or blows. The gaseous effluent which circulates through the exchanger 6 through the extraction duct 42 and transfers its heat to the flow of fluid entering the exchanger 6 and intended to flow through the blowing duct, is derived from the air from the outside of the compost bin 2 and which passes through the composting material to be sucked by the orifices of the drain portion 41 which communicate with the interior of the compost bin 2. In particular, by placing in forced circulation of fluid from the drain portion to the exchanger portion, the outside air is drawn through the material in the compost bin. In contact with said material, the air is converted into a gaseous effluent of composition different from the incoming air and higher temperature than said incoming air. In particular, in contact with the material the incoming air is depleted in oxygen, enriches in carbon dioxide and is charged with water vapor. It can be provided that said circuit 4 is provided with gaseous effluent treatment means at the outlet of the exchanger 6 configured to purify the effluent, for example to reduce the olfactory charge of said gaseous effluent.

Said circulation circuit 4 is provided with liquid discharge means preferably positioned upstream of the fan 43. The liquid discharge can be useful because of the condensation of the gaseous effluent at the level of the drain in contact with the slab temperature usually lower than that of the gaseous effluent sucked by the drains. Said liquids can be reintroduced into the composting material in the rack 2 not surface spray of this material or by other means. Evacuation means may also be positioned at drains 52 for discharging liquids. The or each locker can be located inside a room or in the open air. Preferably, the upper face of the rack 2 is closed, but alternatively it can be provided that said upper face is open. The circulation circuit portion 4 extending from the drain portion 41 includes up to the heat exchanger 6 and / or the flow circuit portion 5 extending from the heat exchanger 6 to the drain portion. 52 includes, can be made of metal or a plastic derivative. Preferably, when said circulation circuit portion is made of metal, it is provided with a thermally insulating sheath.

The wall of said portion of the circulation circuit 4 or 5 has a thermal conductivity in W / m / ° K preferably less than or equal to 0.5. The installation thus makes it possible to recover the sensible and latent heat contained in a first fluid stream formed by the gaseous effluent from a composting bin filled with a material in the active composting phase, to increase the temperature of the a second gas stream which is blown via drains 52 into a material (waste, maturing or composted mixture, etc.) to be heated and / or dried, distinct from that for which the sensible and latent heat is valued. The recovery of the sensible and latent heat contained in the first stream from the composting bin is obtained by lowering its temperature by heat exchange with the second gas stream to be heated within the exchanger 6. The lowering of temperature causes condensation of part of the steam it contains. The temperature of the second stream at its inlet into the exchanger is lower than that of the first stream at its outlet from the exchanger.

The heat exchanger is dimensioned so as to transmit to the second flow through the circuit 5, the maximum of the heat contained in sensitive and latent forms in the first gas flow which passes through the circuit 4. Optimal recovery of the sensible and latent heat contained in the first flow, it is possible to heat a second flow rate several times greater than the flow rate of the first flow. As mentioned above, such an installation and the corresponding calorie transfer process allow: the in-situ valorization of a high quantity of heat usually lost, the recovery of a first material in favor of the drying of a second material for example for its composting (mud, waste, digestate, etc.), its material recovery (mud, compost, etc.), or its energy recovery by heat treatment such as incineration. It can be provided that said installation comprises means for recovering the liquid from the fluid flowing through the extraction duct 42 and means 5 for reinjecting said liquid into the compost bin 2. The present invention is not limited to the embodiments described and shown, but the skilled person will be able to make any variant within his mind.

Claims (11)

REVENDICATIONS1. Calorie transfer facility (1) comprising: a rack (2) adapted to contain a biodegradable organic material, said rack (2) having a first floor (20), such as a concrete slab, - a first circuit (4) ) of fluid circulation comprising: - a portion (41) forming a drain, perforated along its length, located under or flush with the face of the first floor (20) facing the inside of the rack and at least part of the orifices communicates with the interior of the rack (2), and - a part (42), called the extraction duct, which extends said drain (41), - means (43) for forced circulation of fluid from the part forming a drain (41) towards the extraction duct portion (42), such as a fan, - a second floor (80), such as a concrete slab, having a face, said face-up, suitable receiving a material to be heated and / or dried; - a second fluid circulation circuit (5) comprising a portion (51), called a blow duct, and a drain portion (52), perforated along its length, extending said blow duct (51) and located under or flush with the top face of the second floor ( 80), at least a portion of the orifices of said drain (52) communicating with the top face of said second floor (80), - means (59) for forced circulation of fluid from the blow duct portion (51). ), such as a fan, to the drain portion (52) of the second circuit, - a heat exchanger (6) for heat exchange between the flow of fluid flowing in the extraction duct (42) and the flow of fluid flowing in the blowing duct (51). 30 2. Installation (1) according to claim 1, characterized in that the outlet of the extraction duct (42) and the inlet of said blowing duct (51) are distinct. 3. Installation (1) according to one of the preceding claims, characterized in that said first circulation circuit (4) associated with the rack (2) is provided with liquid evacuation means positioned at least downstream of the part forming a drain (41). 4. Installation (1) according to one of the preceding claims, characterized in that the wall of said first circulation circuit (4) which extends from the included drain portion (41) to the exchanger (6). ) and / or the wall of said second circulation circuit (5) which extends from the heat exchanger (6) to the drain portion (52) included, has a thermal conductivity in W / m / ° K lower or equal to 0.5. 5. Installation (1) according to one of the preceding claims, characterized in that the flow of fluid flowing through the extraction duct (42) and that flowing through the blowing duct (51) circulate in the exchanger (6). ) of heat in opposite directions from each other. 6. Installation (1) according to one of the preceding claims, characterized in that said rack (2) has an air inlet in the upper part of the rack (2). 7. Installation (1) according to one of the preceding claims, characterized in that the installation comprises another rack capable of containing said material to be dried and / or heated, said second floor (80) forming the bottom of said other rack, said at least a portion of the orifices of said drain (52), which communicates with the top face of said second floor (80), opening into said other rack. 8. Method of calorie transfer using an installation according to one of the preceding claims, between a material contained in said rack (2) and a material disposed on said second floor (80), characterized in that a forced circulation of air is generated from the portion of the first drain circulation circuit (41) towards the extraction duct portion (42), so that, by suction at the drain (41), air, outside the rack (2), passes through the material present in the rack (2) forming a gaseous effluent of composition different from the air entering said rack and of higher temperature, said gaseous effluent passing through the duct extraction (42) and passing through the exchanger (6), - a forced circulation of air is generated from the part of the second circulation circuit (5) forming a blow duct (51) towards the drain part (52) said second circuit (5) of circulation, of fate e air passes through the exchanger (6) to recover calories from the fluid flowing through the extraction duct (42) and passes through the blowing duct (51) to be diffused by the orifices of the drain (52) in the material 15 disposed on said second floor (80). 9. The method of claim 8, characterized in that said method is used to dry the material placed on said second floor (80). 10. The method of claim 8, characterized in that said method is used to heat the material placed on said second floor (80). 11. Method according to one of claims 8 to 10, characterized in that the material placed on the second floor (80) is removed, and in that the material present in the rack (2) is moved, on the second floor (80), a new material being introduced into said bin (2).