FR3134729A1 - Livestock building effluent treatment device, installation and associated method - Google Patents

Abstract

Device for treating livestock building effluent, associated installation and method The invention relates to a device (14A) for treating livestock building effluent (12) comprising a phase separator (20) and a chain of transport of effluent (22) to the separator (20), the transport chain comprising an effluent buffer tank (28) and a mechanical conveyor (30). The mechanical conveyor (30) is capable of transporting effluents from a supply inlet (36A), receiving as input the effluents contained in the buffer tank (28), to a supply outlet (36B) supplying the separator phase (20), the mechanical supply conveyor (30) being capable of completely emptying the buffer tank (28). The buffer tank (28) is configured so that the contained effluents have a heterogeneous dry matter concentration until the moment when said effluents are transported by the mechanical conveyor (30), the buffer tank (28) being fixed in position by relative to the phase separator (20). Figure for abstract: 1

Description

Livestock building effluent treatment device, installation and associated method

The present invention relates to a device for treating livestock building effluent and an associated treatment method.

In some traditional farms, animals are housed in buildings all or part of the year. In animal exercise areas, systems, such as corridors, to collect droppings are installed. The evacuation of these effluents (or slurry in this context) can be carried out by scraping the corridors, and the effluents end up in a dedicated storage pit, awaiting use for spreading. This scraping can be carried out automatically using different systems. Although this simplifies the cleaning of buildings, and eliminates the need to add straw or other absorbent material, which would produce solid manure, this management method generates greater volumes of slurry than in a manure system. Such volumes are problematic for spreading, particularly in the case of plots far from livestock buildings.

Alternatively, it is also known to treat the slurry by separation into two phases, liquid and solid. Such treatment has advantages, such as the possibility of spreading the more diluted liquid fraction in larger quantities on the plots around the building, and of transporting the reduced volume of the more concentrated solid fraction to the distant plots.

In a known treatment, the scraped slurry is brought into a pre-pit to homogenize the slurry before phase separation, the pre-pit generally having a volume of 150 m3 for 3 m depth.

The pre-pit includes a stirrer which keeps the solids in suspension, such a stirrer generally being constructed of cast iron with stainless steel blades and requiring an average power of 11 kW. In addition, the pre-pit also includes a submersible centrifugal chopper pump, with an average power of 11 kW, which crushes the fibers, strands and large pieces of straw from the slurry.

Subsequently, the slurry is raised by pumping to a platform approximately 3m from the ground, where it is loaded into a vibrating belt, screw or centrifugal phase separator, generally requiring an average power of 5.5 kW . The purpose of the pre-pit and its equipment is to dilute and homogenize the fresh effluent whose solid matter concentration is initially between 12% and 15% by mass, to obtain a solid matter concentration between 3% and 4%, the homogenized slurry then being sufficiently liquid to be pumped and accepted at the inlet of the vibrating, screw or centrifugal phase separator.

Following separation, the liquid phase leaving the phase separator subsequently feeds a storage pit, where it is stored awaiting use for spreading. The solid phase is simply discharged onto a pile below the platform.

However, despite its advantages, such a system also has many disadvantages and only a small number of breeders make the necessary investments to equip themselves with such a system. Indeed, this system requires mixing and chopping the slurry before phase separation, which leads to significant equipment costs and high and complex maintenance. In particular, permanently submerged parts are a more important source of maintenance than other equipment.

In addition, this system requires significant modification of the structure of the breeding facility to be able to be implemented. However, these modifications are expensive, or even impossible in certain existing installations.

In addition, the energy consumption of such a system is very high (around 27.5 kW), which is hardly compatible with the current logic of environmental protection and reduction of energy consumption.

There is therefore a need for an effluent treatment device which requires low and simple maintenance, which is also simple to implement on already existing installations, and which has low energy consumption.

To this end, the subject of the present invention is a device for treating livestock building effluents comprising at least one phase separator and at least one effluent transport chain to the phase separator;

the effluent transport chain comprising at least one effluent buffer tank capable of being supplied with effluent and a mechanical feed conveyor,

the mechanical feed conveyor having a feed inlet and a feed outlet, the mechanical feed conveyor being capable of transporting effluent from the feed inlet to the feed outlet, the inlet of the mechanical feed conveyor being arranged so that the mechanical feed conveyor is suitable for receiving at entry the effluents contained in the buffer tank,

the buffer tank being configured so that the effluents contained in the buffer tank have a heterogeneous concentration of dry matter until the moment when said effluents are transported by the mechanical feed conveyor, the buffer tank being fixed in position relative to the phase separator,

the buffer tank and the mechanical feed conveyor being arranged so that the mechanical feed conveyor is capable of completely emptying the buffer tank of the effluents contained in the buffer tank, when the buffer tank is no longer supplied with effluent, and

the phase separator being suitable for receiving effluents coming from the input outlet of the mechanical input conveyor, the phase separator being suitable for separating the effluents between a liquid phase and a solid phase, the phase separator comprising at least a solid phase outlet through which the solid phase is capable of being evacuated.

Thanks to the elements and their arrangement of such a treatment device, the phases can be separated directly after evacuation from the breeding building; it is not necessary to mix and grind them before separating them again. It is therefore possible to eliminate the need to carry out expensive work to create a homogenization pre-pit, and it is possible to eliminate expensive equipment, such as a mixer and a chopper pump.

Such a device requires little maintenance and few modifications to the structure of the breeding installation, which reduces investment and operating costs. It is also estimated that the treatment device requires an investment cost estimated at one third of known systems.

The energy consumption of this system is also lower than for known systems. In particular, a significant gain in electrical consumption is estimated, around 6 kW of average power, compared to the average power of 27.5 kW required for the known systems described above.

The device according to the invention may comprise one or more of the following characteristics, taken in isolation or in any technically possible combination:

- the mechanical feed conveyor is capable of mechanically raising effluent from the feed inlet to the feed outlet;

- the mechanical feed conveyor comprises a frame and at least one movable surface relative to the frame, the movable surface being capable of mechanically raising effluent from the feed inlet to the feed outlet;

- the mechanical feed conveyor is at least capable of authorizing and interrupting a gravity flow of the effluents from the feed inlet to the feed outlet, the mechanical feed conveyor comprising a feed conduit and at minus one valve;

- the phase separator comprises a frame and at least one rotating element capable of being rotated relative to the frame to separate effluents entering the phase separator, the rotating element being advantageously made of high density plastic;

- the phase separator is a rotating roller multi-disc separator, a cascade roller press separator or a rotating helical screw multi-disc separator;

- the phase separator is configured to separate effluents comprising a dry matter concentration greater than or equal to 10%, preferably greater than or equal to 12%; and advantageously less than or equal to 20%, preferably less than or equal to 18%, better still less than or equal to 15%; And

- the treatment device also comprises a solid phase output chain, the solid phase output chain comprising at least one mechanical output conveyor, the mechanical output conveyor having an inlet and an outlet, the mechanical output conveyor being clean to receive the solid phase from the solid phase outlet of the phase separator and capable of transporting the solid phase from the inlet to the outlet.

In addition, the invention relates to a breeding installation comprising at least one device for treating effluent from the breeding building as described above.

The breeding installation according to the invention may comprise one or more of the following characteristics, taken in isolation or in any technically possible combination:

- the breeding installation comprises at least one effluent evacuation corridor suitable for supplying effluent to the buffer tank, the buffer tank being delimited in the evacuation corridor, the intake inlet of the mechanical intake conveyor being received in the buffer tank;

- the breeding installation comprises at least one effluent evacuation corridor capable of supplying effluent to the buffer tank, and, at least one storage pit, the phase separator comprising a liquid phase outlet through which the liquid phase is capable of being evacuated, the liquid phase outlet being connected to the storage pit, the evacuation corridor opening onto the storage pit, the buffer tank being arranged at the end of the evacuation corridor and being suspended above the storage pit, the intake inlet of the mechanical intake conveyor being received in the buffer tank.

Furthermore, the invention relates to a method of treating effluent from a livestock building comprising the following successive steps:

- a step of transporting effluent to a phase separator, the transport step comprising:

* receiving the effluents in a buffer tank, the buffer tank being fixed in position relative to the phase separator,

* the transport of effluents coming from the buffer tank by a mechanical feed conveyor, the effluents contained in the buffer tank having a heterogeneous dry matter concentration until the moment when said effluents are transported by the mechanical feed conveyor, the buffer tank and the mechanical feed conveyor being arranged so that the mechanical feed conveyor is capable of completely emptying the buffer tank of the effluents contained in the buffer tank, when the buffer tank is no longer supplied with effluent, and

* the reception by the phase separator of the effluents coming from the mechanical conveyor; And

- a step of separating the effluents between a liquid phase and a solid phase by the phase separator.

Also, the invention relates to a method of assembling a treatment device for a breeding installation, the breeding installation initially comprising a breeding building, the assembly method comprising the provision of the phase separator and the arrangement of the effluent transport chain.

The arrangement step includes the arrangement of the effluent buffer tank and the arrangement of the mechanical feed conveyor, the feed inlet being arranged so that the mechanical feed conveyor is suitable for receiving input the effluents contained in the retention tank, the mechanical intake conveyor being arranged so that the phase separator is suitable for receiving effluents coming from the intake outlet.

At the end of the assembly method, the processing device described above is obtained.

The invention will be better understood on reading the description which follows, given solely by way of example and made with reference to the drawings in which:

there is a schematic perspective view of a breeding installation comprising a first embodiment of an effluent treatment device;

there is a schematic side view of a first embodiment of an effluent treatment device;

there is a schematic view of a breeding installation comprising a second embodiment of an effluent treatment device; And

there is a schematic side view of a third embodiment of an effluent treatment device.

A breeding facility 10 is illustrated in the .

Breeding facility 10 of the comprises at least one animal breeding building 12 and a device 14A for treating effluent from the breeding building 12 according to a first embodiment.

The breeding installation 10 more preferably comprises at least one effluent evacuation corridor 32.

In addition, the breeding installation 10 also includes at least one storage pit 26, for example a single storage pit 26.

The breeding building 12 is suitable for receiving animals 16.

The animals 16 are preferably bovine animals, for example cows visible on the . Alternatively, the animals 16 are porcine, equine, sheep, or goat animals.

The breeding building 12 is preferably suitable for receiving animals 16 placed in tied or free stalls. The livestock building 12 is then in particular a stable.

The livestock building 12 delimits at least one effluent evacuation opening 18, and, in the example of the , at least two effluent evacuation openings 18.

The effluents subsequently treated by the treatment device 14A contain the droppings emitted by the animals 16 of the livestock building 12.

The treated effluents, for example, also contain absorbent litter, such as cereal straw. Alternatively, the treated effluents are devoid of absorbent litter.

The treated effluent therefore forms slurry.

The breeding installation 10 preferably comprises an evacuation corridor 32 for each of the evacuation openings 18 of the effluents of the breeding building 12.

Each evacuation corridor 32 is suitable for collecting animal effluent 16.

The evacuation corridor 32 passes through the evacuation opening 18 of the livestock building 12 with which it is associated.

The evacuation corridor 32 extends inside the livestock building 12.

Inside the breeding building 12, the animals 16 are for example aligned on either side of the evacuation corridor 32.

The evacuation corridor 32 also extends, for example, outside the livestock building 12.

The evacuation corridor 32 is substantially flat, and preferably extends substantially horizontally. Alternatively, the evacuation corridor 32 has at least one region extending with a slope having an inclination relative to the horizontal, the inclination being non-zero and less than or equal to 3°, to facilitate the evacuation of effluent from the livestock building 12.

The evacuation corridor 32 leads in this example to the storage pit 26.

The storage pit 26 is suitable for storing the liquid phase of the effluent after separation by the phase separator 20, as explained in more detail later.

Storage pit 26 has a total storage volume greater than or equal to 400 m3.

The storage pit 26 has a bottom and side walls delimiting the storage volume. The side walls are for example substantially vertical.

The storage pit 26 has a depth, for example, greater than 2 m.

The liquid phase contained in the storage pit 26 is intended to be used for spreading.

The treatment device 14A generally comprises at least one phase separator 20 and at least one effluent transport chain 22 up to the phase separator 20.

Preferably, the treatment device 14A comprises an effluent transport chain 22 for each of the effluent evacuation openings 18 of the livestock building 12.

In other words, the treatment device 14A comprises an effluent transport chain 22 for each of the evacuation corridors 32.

Thus, in the example illustrated, the treatment device 14A comprises at least two effluent transport chains 22.

The treatment device 14A also advantageously comprises a solid phase output chain 24.

The effluent transport chains 22 are suitable for transporting the effluents coming from the breeding building 12 in parallel.

More precisely, in the example illustrated, each effluent transport chain 22 is capable of transporting, in parallel with each other chain 22, the effluents coming from the associated evacuation corridor 32 to the separator 20.

By “in parallel”, we mean that the transport of effluents by one of the chains 22 is independent of the possible transport of effluents by the other chains 22. In particular, these parallel transports may be simultaneous or not.

As illustrated on the , each effluent transport chain 22 comprises at least one buffer tank 28 and a mechanical feed conveyor 30.

Thus, in each transport chain 22, the effluent buffer tank 28, and the mechanical feed conveyor 30 are arranged from upstream to downstream of the effluent treatment.

Here and subsequently, the terms “upstream” and “downstream” refer to the direction of effluent treatment.

For each transport chain 22, the buffer tank 28 is arranged to be supplied with effluent.

More precisely, the buffer tank 28 arranged to be supplied with effluent coming from the evacuation corridor 32 and thus forms a discharge point of the evacuation corridor 32.

To do this, the effluents are for example scraped from the evacuation corridor 32 associated manually, and/or by at least automatic scraper (for example chain, cable or other) 34 visible on the , and/or by scraping robot 35 visible on the , and/or by hydrocleaning. Such cable or chain scrapers 34, scraping robots 35 and hydrocleaning are known to those skilled in the art and will not be described in more detail below.

The buffer tank 28 is arranged to be fixed in position relative to the phase separator.

In the first embodiment, the buffer tank 28 is directly supplied with effluent from the evacuation corridor 32. More precisely, the buffer tank 28 is arranged so that the scraped effluent falls by gravity into the buffer tank 28 from the corridor d evacuation 32.

In the exemplary embodiment illustrated on the , the buffer tank 28 is delimited in the evacuation corridor 32.

The buffer tank 28 is in particular received in a cavity dug in the evacuation corridor 32, the evacuation corridor 32 extending beyond the buffer tank 28 until opening onto the storage pit 26.

In this example, the buffer tank 28 is thus interposed between the breeding building 12 and the storage pit 26.

Preferably, the buffer tank 28 comprises walls 62 delimiting a volume for receiving the effluents.

The effluent reception volume advantageously has a total volume less than or equal to 25 m3, preferably less than or equal to 20 m3, for example less than or equal to 15 m3.

The buffer tank 28 preferably has a depth greater than or equal to 30 cm, advantageously less than or equal to 120 cm.

The depth is for example defined as the vertical distance between the lowest point of the buffer tank 28 and the evacuation corridor 32 bordering the tank 28.

The buffer tank 28 is configured so that the effluents contained in the buffer tank 28 have a heterogeneous concentration of dry matter until the moment when the effluents leave the buffer tank 28, that is to say until the moment when they are transported by the mechanical feed conveyor 30 in the first embodiment 14A.

In particular, the dry matter concentration of the effluent is lower at the surface than at the lowest point of the buffer tank 28.

The effluents received in the buffer tank 28 comprise for example a free liquid phase.

The buffer tank 28 is configured so that the effluents are received there without mechanical mixing or chopping of the effluents.

The buffer tank 28 is in particular devoid of a stirrer and a chopper pump capable of achieving a substantially homogeneous dry matter concentration of the effluents contained in the buffer tank 28. In the context of the invention, the mechanical feed conveyor 30 n is not considered such a brewer.

The buffer tank 28 and the mechanical feed conveyor 30 are arranged so that the mechanical feed conveyor 30 is capable of completely emptying the buffer tank 28 of the effluents contained in the buffer tank 28, when the buffer tank 28 is no longer fed with effluent.

By “no longer supplied with effluent”, we mean a situation in which the buffer tank 28 was previously supplied and is no longer supplied.

Thus, the buffer tank 28 is intended to be emptied at the end of each evacuation phase (or cycle), as explained in more detail below.

The mechanical feed conveyor 30 is arranged downstream of the buffer tank 28.

The mechanical feed conveyor 30 is configured to supply the phase separator 20 with effluents coming from the buffer tank 28.

By “mechanical conveyor” is meant a conveyor which is capable of transporting effluents with a dry matter concentration greater than 30%, preferably greater than 50%, advantageously greater than 75%. In particular, a pumping system with a pump creating a liquid flow of effluent is not a mechanical conveyor within the meaning of the invention.

The mechanical feed conveyor 30 has a feed inlet 36A and a feed outlet 36B, and is capable of transporting effluent from the feed inlet 36A to the feed outlet 36B.

In the first embodiment, the mechanical feed conveyor 30 is capable of mechanically raising effluent from the feed inlet 36A to the feed outlet 36B.

The intake inlet 36A of the mechanical intake conveyor 30 is arranged so that the mechanical intake conveyor 30 is suitable for receiving as input the effluents contained in the buffer tank 28.

More precisely, the feed inlet 36A of the mechanical feed conveyor 30 is received in the buffer tank 28.

Preferably, the intake inlet 36A of the mechanical intake conveyor 30 is arranged at the lowest point of the buffer tank 28. For example, the intake inlet 36A forms the lowest point of the buffer tank 28.

Preferably, the buffer tank 28 is secured to the mechanical feed conveyor 30, in particular the feed inlet 36A is secured to the walls 62 of the buffer tank 28.

In the first embodiment, the feed outlet 36B of the mechanical feed conveyor 30 is arranged higher than the feed inlet 36A.

The intake outlet 36B of the mechanical intake conveyor 30 is arranged higher than the phase separator 20.

Generally, the mechanical feed conveyor 30 comprises a frame 38 and at least one movable surface 40 relative to the frame 38, the movable surface 40 being capable of mechanically raising effluent from the feed inlet 36A towards the outlet of contribution 36B.

The movable surface 40 is in particular capable of mechanically raising effluents by its movement relative to the frame 38 from a position located substantially at the level of the intake inlet 36A to another position located substantially at the level of the outlet d contribution 36B.

The mechanical feed conveyor 30 further comprises, for example, a motor capable of moving the movable surface 40 relative to the chassis 38.

The buffer tank 28 and such a mechanical feed conveyor 30 together provide a role of buffer and regulation of the quantity of effluent which is sent over time to the phase separator 20, to enable the separation objectives to be achieved. considered.

In the preferred example illustrated in Figures 1 and 2, the mechanical feed conveyor 30 comprises an endless screw, the endless screw defining said movable surface 40 capable of mechanically raising effluent.

The endless screw is thus movable in rotation relative to the frame 38.

For example, the worm gear is rigid or flexible.

For example, the endless screw is with or without a core.

The endless screw is for example made of steel, stainless steel or polymers.

As illustrated on the , the mechanical feed conveyor 30 is inclined relative to a horizontal plane.

The mechanical feed conveyor 30 is in particular inclined towards the phase separator 20.

Preferably, the mechanical feed conveyor 30 extends in a direction of elevation having an angle of inclination with a horizontal plane, the angle of inclination being less than or equal to 60°, preferably less than or equal to 30°.

In the example illustrated, the direction of elevation is in particular the direction in which the endless screw extends.

Such an inclination aims to compensate for the difference in height between the phase separator and the buffer tank 28.

For each transport chain 22, the phase separator 20 is arranged downstream of the mechanical feed conveyor 30 of the transport chain 22.

More precisely, the effluents transported by the different transport chains 22 come together at the phase separator 20.

Thus, the phase separator 20 is placed downstream of the mechanical feed conveyor 30 of each transport chain 22.

The phase separator 20 is placed on the ground.

The phase separator 20 is arranged in this example between two evacuation corridors 32.

The phase separator 20 is suitable for receiving effluents coming from the input outlet 36B of the mechanical input conveyor 30 of each transport chain 22.

In the example illustrated, the effluents fall by gravity onto the phase separator 20 from the intake outlet 36B of the mechanical intake conveyor 30 of each transport chain 22.

Preferably, as illustrated in the , the treatment device 14A comprises an inlet hopper 42 downstream of the intake outlets 36B of the mechanical intake conveyors 30 and upstream of the phase separator 20. The inlet hopper 42 is then suitable for directing the effluents coming from the input outputs 36B towards an input 44 of the phase separator 20.

The inlet 44 of the phase separator 20 is located at a height less than or equal to 1.0 m from each evacuation corridor 32, preferably substantially at the same height level as each evacuation corridor 32. The height is taken vertically.

The phase separator 20 is capable of separating the effluents received at the inlet 44 between a liquid phase and a solid phase.

The phase separator 20 is in particular suitable for separating the effluents without the need for mechanical mixing or prior chopping of the effluents.

The phase separator 20 is thus suitable for separating materials with a heterogeneous concentration of dry matter and a high concentration of solids at the input.

Advantageously, the phase separator 20 is capable of separating effluents comprising a dry matter concentration greater than or equal to 10%, and preferably greater than or equal to 12%.

Advantageously, the phase separator 20 is capable of separating effluents comprising a dry matter concentration less than or equal to 20%, preferably less than or equal to 18%, better still less than or equal to 15%.

A person skilled in the art knows how to determine the dry matter concentration of effluents. An example of a method includes the steps: initially weighing a product sample, and weighing it again after drying in an oven according to a 24-hour drying protocol at 105°C (for example). The dry matter content of the product is expressed as a percentage of the initial mass. For example, we apply the formula from standard EN 13406 (calculation of dry matter content). For the same sample, this operation is carried out for example 5 times. We then understand the dry matter concentration determined for the effluents as the arithmetic average of the five determined contents.

The phase separator 20 comprises at least one solid phase outlet 46, visible on the , by which the solid phase is capable of being evacuated, after separation of the effluents at the inlet 44.

The solid phase separated by the phase separator 20 preferably comprises a dry matter concentration greater than or equal to 20%.

The phase separator 20 also includes a liquid phase outlet 48, illustrated in the , by which the liquid phase is capable of being evacuated, after separation of the effluents at the inlet 44.

The separated liquid phase, at the liquid phase outlet 48, preferably comprises a dry matter concentration less than or equal to 1%.

The liquid phase outlet 48 is connected to the storage pit 26.

The liquid phase outlet 48 is distinct from the solid phase outlet 46.

Generally, the phase separator 20 comprises a frame 50 and at least one rotary element capable of being rotated relative to the frame 50 to separate effluents at the inlet 44 of the phase separator 20.

The frame 50 delimits a receiving volume 52 of the separated liquid phase, the liquid phase outlet 48 being connected to a low point of the receiving volume 52.

In the example of realization of the , the phase separator 20 is a multi-disc separator with rotating rollers.

The phase separator 20 then further comprises disks 54, rollers and a motor or geared motor.

The rollers and discs 54 then form the rotating elements of the separator.

The rollers are parallel to each other.

The rollers are capable of being rotated relative to the frame 50 by the motor or servomotor.

The discs 54 are mounted on the rollers.

The shape of the discs 54, associated with the rotating rollers, move the effluent from the inlet 44 of the phase separator 20, allowing the liquid phase to separate from the solid phase and fall by gravity into the receiving volume 52 of the frame 50.

The discs 54 thus preferably have an elongated shape, such as an elliptical, oval, or oblong shape.

The discs 54 and/or the columns are advantageously made of high density plastic.

High density plastic, for example, has a crystallinity rate greater than or equal to 80%. The crystallinity rate is for example measured by infrared spectroscopy.

High density plastic is for example high density polyethylene.

The use of a high-density plastic, instead of stainless steel in the functional components, makes it possible to drastically reduce the cost of raw materials with equivalent resistance.

The solid phase output chain 24 is arranged downstream of the phase separator 20.

The solid phase output chain 24 comprises at least one mechanical solid phase output conveyor 56.

Preferably, as illustrated in the , the solid phase output chain 24 comprises at least two mechanical solid phase output conveyors 56 arranged successively. Alternatively, as shown in the , the solid phase output chain 24 only includes a single mechanical output conveyor 56.

At the end of the solid phase output chain 24, the solid phase is deposited in piles 58 in a storage area, in particular away from the storage pit 26.

In the first embodiment, each mechanical outlet conveyor 56 is configured to evacuate the solid phase at the outlet of the phase separator 20.

More precisely, each mechanical output conveyor 56 has an input 60A and an output 60B.

Each mechanical outlet conveyor 56 is capable of transporting the solid phase from the inlet 60A to the outlet 60B.

In particular, each mechanical output conveyor 56 comprises a frame and at least one movable surface relative to the frame, the movable surface being suitable for transporting the solid phase from the inlet 60A to the outlet 60B.

Each mechanical output conveyor 56 is a conveyor belt (as illustrated in the ), a baffle elevator (as shown in the ) or a rigid or flexible endless screw. Other mechanical transporters could be considered by those skilled in the art.

At least one of the mechanical outlet conveyors 56 is capable of receiving the solid phase from the solid phase outlet 46 of the phase separator 20. The solid phase coming from the solid phase outlet 46 of the phase separator 20 then falls by gravity into the entrance 60A of this transporter 56.

In the first embodiment, each mechanical outlet conveyor 56 is preferably capable of mechanically raising the solid phase from the inlet 60A to the outlet 60B.

For each mechanical outlet conveyor 56, the outlet 60B is then for example arranged higher than the inlet 60A.

The mechanical outlet conveyors 56 are arranged successively so that the effluents, falling by gravity from the outlet 60B of one of the conveyors 56, are received by the inlet 60A of the next conveyor 56.

A second embodiment of an effluent treatment device 14B will now be described with reference to the .

Only the differences between the first embodiment and the second embodiment will be described below.

In the second embodiment 14B, for each transport chain 22, the buffer tank 28 is arranged at the end of the evacuation corridor 32 and is suspended above the storage pit 26, the intake inlet 36A of the mechanical feed conveyor 30 being received in the buffer tank 28.

The buffer tank 28 is arranged as an extension of the evacuation corridor 32.

In particular, the buffer tank 28 is then not delimited in the evacuation corridor 32.

The buffer tank 28 then comprises walls 62 fixed to the side walls of the storage pit 26.

The walls 62 are arranged above the bottom of the storage pit 26.

The mechanical feed transport 30 then rests for example on the walls 62. Alternatively or in addition, the transport chain 22 comprises a bracket and a hoist (not illustrated) supporting the mechanical feed transport 30.

A third embodiment of an effluent treatment device 14C will now be described with reference to the .

Only the differences between the first embodiment and the third embodiment will be described below.

In the third embodiment 14C, the mechanical feed conveyor 30 is at least capable of authorizing and interrupting a gravity flow of effluents from the feed inlet 36A to the feed outlet 36B.

Preferably, the mechanical feed conveyor 30 is also capable of regulating the flow rate of the gravity flow of the effluents from the feed inlet 36A to the feed outlet 36B.

To do this, the mechanical feed conveyor 30 comprises a feed conduit 64 and at least one valve 66.

The intake conduit 64 defines the intake inlet 36A and the intake outlet 36B.

The intake conduit 64 is arranged lower than the buffer tank 28, so that the effluents can flow by gravity from the buffer tank 28 towards the intake conduit 64.

The intake inlet 36A of the mechanical intake conveyor 30 forms the lowest point of the buffer tank 28.

The feed outlet 36B of the mechanical feed conveyor 30 is arranged at the same level or preferably lower than the feed inlet 36A.

In the example illustrated on the , the conduit has at least one inclined region extending with a slope having an inclination relative to the horizontal, the inclination being non-zero and less than or equal to 3°. The inclined region is for example downstream of the valve 66 in the example of the .

Alternatively, the intake conduit 64 is substantially straight.

In the event of a sufficient difference in ground level, the buffer tank 28 and the supply conduit 64 are placed in relation to each other, for example being placed on the ground or suspended

Alternatively, the intake conduit 64 is received in a passage dug in the ground. The supply conduit 64 then opens for example into the side walls of the storage pit 26. In such an example, the phase separator 20 is then for example arranged in the storage volume delimited by the storage pit 26, by example so as to be raised relative to the bottom of pit 26.

The valve 66 is placed in the intake conduit 64.

The valve 66 has an opening configuration and a closing configuration, the valve 66 being capable of switching from one of the configurations to the other.

An operator is in particular able to switch the valve 66 from one of its configurations to the other by actuation of a member connected to the valve 66.

In the opening configuration, the valve 66 authorizes the gravity flow of effluents from the intake inlet 36A to the intake outlet 36B. For example, in the opening configuration, valve 66 offers no obstruction to the gravity flow of effluent.

In the closed configuration, the valve 66 interrupts the gravity flow of effluent from the intake inlet 36A to the intake outlet 36B.

Preferably, the valve 66 also has at least one stable intermediate configuration, illustrated in the , in which the valve 66 authorizes the gravity flow of the effluents by providing obstruction to part of the gravity flow. It is then possible to regulate the flow rate of the gravity flow of the effluents from the intake inlet 36A to the intake outlet 36B.

The valve 66 has, for example, a plurality of distinct stable intermediate configurations.

The flow rate authorized by the valve 66 in each intermediate configuration is lower than that authorized in the opening configuration.

Valve 66 is preferably a gate valve.

Alternatively, the valve 66 is for example a butterfly valve, or a control valve.

In the third embodiment also, the buffer tank 28 and the mechanical feed conveyor 30 together provide a role of buffer and regularization of the quantity of effluent which is sent over time to the phase separator 20, to allow to achieve the envisaged separation objectives.

A method of treating livestock building effluent 12 will now be described.

The processing method is preferably implemented by the processing device 14A, 14B, 14C described above.

The method includes at least one phase of evacuation and effluent treatment. Preferably, the method comprises the periodic repetition of such an evacuation and treatment phase.

The evacuation and treatment phase includes a preliminary step of accumulation of effluents in the breeding building 12, the effluents comprising the droppings emitted by the animals 16 of the breeding building 12.

The effluents are then evacuated from the breeding building 12.

Subsequently, the evacuation and treatment phase includes an effluent transport step to phase separator 20.

The transport step comprises at least successively the reception of the effluents in the buffer tank 28, the buffer tank 28 being fixed in position relative to the phase separator 20.

The transport step also includes the transport of effluents coming from the buffer tank 28 by the mechanical feed conveyor 30.

In addition, the transport step includes the reception by the phase separator 20 of the effluents coming from the mechanical conveyor 30.

The effluents contained in the buffer tank 28 have a heterogeneous concentration of dry matter until the moment when said effluents are transported by the mechanical feed conveyor 30.

In other words, from the moment the effluents are received in the buffer tank 28, the effluents are transported to the phase separator 20 without mechanical mixing or chopping.

During this transport step, the effluents are transported out of the buffer tank 28 until the buffer tank 28 is emptied.

Thus, when the buffer tank 28 is no longer supplied with effluent, the mechanical feed conveyor 30 completely empties the buffer tank 28 of the effluent contained therein.

In particular, at the end of the evacuation and treatment phase, the buffer tank 28 is empty.

The effluents are transported in parallel by each of the transport chains 22.

The evacuation and treatment phase subsequently includes a step of separation of the effluents between a liquid phase and a solid phase by the phase separator 20.

The evacuation and treatment phase subsequently includes a step of exiting the solid phase, for example via the exit chain 24 and each mechanical exit conveyor 56.

The evacuation and treatment phase also includes, in parallel with the exit of the solid phase, a stage of exit of the liquid phase to the storage pit 26.

A method of assembling the treatment device 14A, 14B, 14C for the breeding installation 10 will now be described.

The breeding installation 10 initially comprises the breeding building 12, and for example the evacuation corridor(s) 32 and the storage pit 26.

The assembly method includes the supply of the phase separator 20 and the arrangement of the effluent transport chain 22 in the installation 10.

The arrangement step includes in particular the arrangement of the effluent buffer tank 28 and the arrangement of the mechanical feed conveyor 30.

In the case of the first embodiment of the treatment device 14A, the buffer tank 28 is made so that it is delimited in the evacuation corridor 32. A cavity is dug to receive the walls 62 of the buffer tank 28.

In the case of the second embodiment of the treatment device 14B, the buffer tank 28 is made so that it is suspended above the storage pit 26. For example, the buffer tank 28 is then made by fixing walls 62 to the side walls of the storage pit 26.

In the case of the third embodiment of the treatment device 14C, the buffer tank 28 is for example placed on the ground, in the event of a sufficient difference in height for it to be suitable for being supplied with effluent from the evacuation corridor 32. Alternatively, the buffer tank 28 is made for example in a manner similar to the first or second embodiments.

When the buffer tank 28 is arranged, no effluent pump, nor mechanical effluent mixer, is placed in the buffer tank 28.

When arranging the mechanical feed conveyor 30, the feed inlet 36A is arranged so that the mechanical feed conveyor 30 is suitable for receiving as input the effluents contained in the buffer tank 28. For example, the buffer tank 28 is provided integral with the mechanical feed conveyor 30.

In addition, the mechanical input conveyor 30 is arranged so that the phase separator 20 is suitable for receiving effluents coming from the input outlet 36B.

In the case of the third embodiment 14C, in the event of a sufficient difference in height, the buffer tank 28 and the supply conduit 64 are placed relative to each other by for example being placed on the ground or suspended. Alternatively, a passage is dug to receive the intake conduit 64 of the mechanical intake conveyor 30.

At the end of the assembly method, the processing device 14A, 14B, 14C described above is obtained.

Variants of the first and second embodiments will now be described.

Alternatively, the first and second embodiments can be combined within the processing device. For example, one of the transport chains 22 is then according to the first mode 14A described above, and another of the transport chains 22 is then according to the second mode 14B described above.

Alternatively, the treatment device 14A, 14B, 14C only comprises a single effluent transport chain 22. In particular, the breeding building 12 then delimits, for example, only a single evacuation opening 18 of the effluent.

Alternatively, the mechanical feed conveyor 30 is not an endless screw, but is any other conveyor capable of ensuring the function of mechanically raising effluent from the feed inlet 36A to the feed outlet. 36B. For example, the mechanical feed conveyor 30 is a conveyor belt or a baffle elevator.

Alternatively, for at least one of the transport chains 22 or for each transport chain 22, the buffer tank 28 is not directly supplied with effluent from the evacuation corridor 32. The transport chain 22 comprises a chain evacuator or with cables, or a two-way evacuator, suitable for directly supplying the buffer tank 28. Such evacuators are known to those skilled in the art and will not be described in more detail below.

Alternatively, for at least one of the transport chains 22 or for each transport chain 22, the buffer tank 28 is not directly supplied with effluent from the evacuation corridor 32. The transport chain 22 then comprises for example a system rinse interposed between the evacuation corridor 32 and the buffer tank 28.

The rinsing system comprises a recovery channel arranged to receive the scraped effluent, the scraped effluent falling by gravity into the recovery channel from the evacuation corridor 32, and a channel connecting the recovery channel to the buffer tank 28.

The rinsing system includes a water supply system from the recovery channel to evacuate the effluent to the buffer tank 28 via the channel. To do this, the water supply system includes an inlet connected to a water supply source and an outlet opening into the recovery channel. The transport of effluent from the recovery channel to the buffer tank is done by pouring water into the channel and without pumping the effluent.

Alternatively, phase separator 20 is a cascade roller press separator.

The phase separator 20 then comprises rollers and motors or geared motors. Each roller is capable of being rotated relative to the frame 50, by one of the motors or geared motors, to compress the inlet effluent against a surface of the separator 20 and thus separate the liquid phase from the solid phase.

Alternatively, the phase separator 20 is a multi-disc separator with a rotating helical screw.

The phase separator 20 then comprises discs, a helical screw and a motor or geared motor.

Part of the disks is fixed relative to the frame 50 and the other part of the disks is mounted free to move relative to the frame 50.

Each disk of the phase separator 20 then has an annular shape, the helical screw passing through the disks.

The helical screw is capable of being rotated relative to the frame 50 by the motor or servomotor.

The helical screw has a decreasing pitch from one end close to the inlet 44 of the phase separator 20 towards the other end.

The decrease in the pitch of the screw, associated with the fixed and free disks, impose an increasing pressure on the effluents which allows the liquid phase to separate from the solid phase and to fall by gravity into the receiving volume 52 of the frame 50.

The discs and/or the helical screw are advantageously made of high density plastic, as described above.

Claims (10)

Device for treating (14A, 14B, 14C) livestock building effluents (12) comprising at least one phase separator (20) and at least one effluent transport chain (22) to the phase separator (20);
the effluent transport chain (22) comprising at least one effluent buffer tank (28) capable of being supplied with effluent and a mechanical feed conveyor (30),
the mechanical feed conveyor (30) having a feed inlet (36A) and a feed outlet (36B), the mechanical feed conveyor (30) being capable of transporting effluent from the feed inlet (36A) to the feed outlet (36B), the feed inlet (36A) of the mechanical feed conveyor (30) being arranged so that the mechanical feed conveyor (30) is suitable for receive as input the effluents contained in the buffer tank (28),
the buffer tank (28) being configured so that the effluents contained in the buffer tank (28) have a heterogeneous concentration of dry matter until the moment when said effluents are transported by the mechanical feed conveyor (30), the buffer tank (28) being fixed in position relative to the phase separator (20),
the buffer tank (28) and the mechanical supply conveyor (30) being arranged so that the mechanical supply conveyor (30) is capable of completely emptying the buffer tank (28) of the effluents contained in the buffer tank (28) , when the buffer tank (28) is no longer supplied with effluent, and
the phase separator (20) being suitable for receiving effluents coming from the intake outlet (36B) of the mechanical intake conveyor (30), the phase separator (20) being suitable for separating the effluents between a liquid phase and a solid phase, the phase separator (20) comprising at least one solid phase outlet (46) through which the solid phase is capable of being discharged. Treatment device (14A, 14B) according to claim 1, wherein the mechanical feed conveyor (30) is capable of mechanically raising effluent from the feed inlet (36A) to the feed outlet ( 36B), and, preferably, the mechanical feed conveyor (30) comprises a frame (38) and at least one movable surface (40) relative to the frame (38), the movable surface (40) being able to raise mechanically effluent from the intake inlet (36A) to the intake outlet (36B). Treatment device (14C) according to claim 1, in which the mechanical feed conveyor (30) is at least capable of authorizing and interrupting a gravity flow of effluents from the feed inlet (36A) to the outlet feed (36B), the mechanical feed conveyor (30) comprising a feed conduit (64) and at least one valve (66). Treatment device (14A, 14B, 14C) according to any one of the preceding claims, in which the phase separator (20) comprises a frame (50) and at least one rotary element capable of being rotated relative to the frame (50) to separate effluents at the inlet (44) of the phase separator (20), the rotating element being advantageously made of high density plastic. Processing device (14A, 14B, 14C) according to any one of the preceding claims, wherein the phase separator (20) is a rotating roller multi-disc separator, a cascade roller press separator or a multi-disc separator -rotating helical screw discs. Treatment device (14A, 14B, 14C) according to any one of the preceding claims, in which the phase separator (20) is configured to separate effluents comprising a dry matter concentration greater than or equal to 10%, preferably greater or equal to 12%; and advantageously less than or equal to 20%, preferably less than or equal to 18%, better still less than or equal to 15%. Processing device (14A, 14B, 14C) according to any one of the preceding claims, wherein the processing device (14A, 14B) also comprises a solid phase output chain (24), the output chain (24) solid phase comprising at least one mechanical output conveyor (56), the mechanical output conveyor (56) having an inlet (60A) and an outlet (60B), the mechanical output conveyor (56) being capable of receiving the phase solid from the solid phase outlet (46) of the phase separator (20) and capable of transporting the solid phase from the inlet (60A) to the outlet (60B). Breeding installation (10) comprising a treatment device (14A) according to any one of claims 1 to 7 and at least one effluent evacuation corridor (32) capable of supplying effluent to the buffer tank (28), the buffer tank (28) being delimited in the evacuation corridor (32), the intake inlet (36A) of the mechanical intake conveyor (30) being received in the buffer tank (28). Breeding installation (10) comprising a treatment device (14B) according to any one of claims 1 to 7, at least one effluent evacuation corridor (32) capable of supplying effluent to the buffer tank (28), and, at least one storage pit (26), the phase separator (20) comprising a liquid phase outlet (48) through which the liquid phase is capable of being discharged, the liquid phase outlet (48) being connected to the storage pit (26), the evacuation corridor (32) opening onto the storage pit (26), the buffer tank (28) being arranged at the end of the evacuation corridor (32) and being suspended above of the storage pit (26), the intake inlet (36A) of the mechanical intake conveyor (30) being received in the buffer tank (28). Method for treating livestock building effluent (12) comprising the following successive steps:
- a step of transporting effluents to a phase separator (20), the transport step comprising:
* receiving the effluents in a buffer tank (28), the buffer tank (28) being fixed in position relative to the phase separator (20),
* the transport of effluents coming from the buffer tank (28) by a mechanical feed conveyor (30), the effluents contained in the buffer tank (28) having a heterogeneous concentration of dry matter until the moment when said effluents are transported by the mechanical feed conveyor (30), the buffer tank (28) and the mechanical feed conveyor (30) being arranged so that the mechanical feed conveyor (30) is capable of completely emptying the buffer tank ( 28) effluents contained in the buffer tank (28), when the buffer tank (28) is no longer supplied with effluent, and
* the reception by the phase separator (20) of the effluents coming from the mechanical feed conveyor (30); And
- a step of separating the effluents between a liquid phase and a solid phase by the phase separator (20).