EP1153253A1

EP1153253A1 - Chamber and installation for drying animal waste

Info

Publication number: EP1153253A1
Application number: EP00903742A
Authority: EP
Inventors: Raymond Chardine
Original assignee: Chardine Raymond; Euromatic Systeme
Current assignee: Ansoain Yoldi J Antonio Pedro M Martinez Marchueta
Priority date: 1999-02-02
Filing date: 2000-02-02
Publication date: 2001-11-14
Anticipated expiration: 2020-02-02
Also published as: JP2002537765A; ATE276500T1; WO2000046560A1; MXPA01007730A; EP1153253B1; US6393722B1; DE60013779D1; FR2789163B1; FR2789163A1; AU2552900A; CA2361697A1; JP3743766B2; CA2361697C; ES2228459T3

Abstract

The invention concern a chamber for drying animal waste, in particular poultry manure, adapted to receive a mixture (M) of fresh waste and dry waste, the floor thereof being adapted to retain the mixture (M) while being permeable to air (A), said floor consisting of an assembly of elements (60, 60') each capable of forming means for retaining the waste and including means (T) which periodically enable to transfer outside the chamber (1) and through said floor (6) a fraction of the dry waste. The invention is characterised in that said elements consist of two series of horizontal crosspieces (60, 60') arranged along two superposed parallel planes (P1, P2), said crosspieces (60,60') being arranged such that the floor (6) contains gaps in the vertical direction, and said transfer means (T) consist of at least a sliding drawer horizontally mobile between said two planes (P1, P2) of crosspieces (T), the longitudinal movement of said drawer, capable of sweeping the entire surface of said floor from one end to the other, driving the waste accumulated on said crosspieces (60') of the lower plane (P2) such that they drop by gravity outside the chamber. The invention also concerns a drying installation equipped with such a chamber.

Description

ENJECTION DRYER AND INSTALLATION

ANIMALS

The present invention relates to an enclosure and an installation for drying animal droppings, in particular poultry droppings.

Owing to their high water content, a large number of techniques for drying poultry droppings have already been proposed, the main purpose of which is to obtain a dehydrated and deodorized product, easily usable for subsequent applications. A main application is that of fertilizer.

The simplest method is to inject air inside the livestock buildings above the endless conveyor belts which are arranged under the livestock cages and on which the poultry droppings fall. However, the air is only partially charged with moisture, due to its rapid passage in contact with the thin layer of droppings spread over the conveyors. To obtain a better efficiency, it would be necessary to implement very large volumes of air and to ensure turbulence within it, which is very costly in energy. In some cases, this type of process is implemented in drying tunnels, outside of livestock buildings. The major drawbacks of this type of installation lie in its size and its mechanical complexity.

Document EP-B-0 210 196 describes a method and an installation for drying and conditioning hen manure. The process includes a step of microbiological transformation of the manure, which requires having to carefully monitor all the parameters of the transformation, to be sure of ensuring a good drying of the manure. In addition, the corresponding installation is necessarily complex and expensive. Document US-A-26791 14 relates to an apparatus and a process for the transformation and composting of manure. The device has a conveyor that transports raw manure to the top of a silo. The bottom of the silo is formed by two perforated and converging partitions between which a channel extends. At the bottom of the channel is provided a conveyor arranged in a chute. Above the conveyor extend two parallel rotating shafts provided with blades. The rotational drive of the trees causes part of the manure to be transferred to the conveyor. Pressurized air, possibly charged with humidity, is introduced into the mass of manure, through the lower part of the silo, to ensure its transformation. The air circulates against the current with respect to the manure, which contributes to improving its drying or its transformation. Document DE-A-2723581 relates to a process and an installation for aerobic decomposition of organic solids. The installation includes a device for pre-drying the material, a storage enclosure and a silo for the treated and dry product. This enclosure and this silo communicate by their bottom with a double screw conveyor which achieves an intimate mixture of the pre-dried product and the dry product.

This mixture is then transferred to a mobile bottom decomposition reactor, via a vertical conveyor. The mixture can be selectively directed to a drying tower and the final product is stored in the aforementioned silo.

It should be noted that the movable bottom is, as in the previous document, made up of a set of rotating shafts whose periphery is provided with fingers or blades.

This type of mobile and breathable bottom has serious drawbacks.

Indeed, when the dried excrement agglomerates in the form of clods resembling clods of earth, we are dealing with a particularly hard material. The driving power of the rotating shafts must be particularly high in order to break up the clods and pass them through the gaps between the fingers or blades of two neighboring shafts. Such an increase in power is costly in energy. Furthermore, when the shafts are at rest, that is to say not actuated in rotation, the aforementioned interstices necessarily allow the most fluid fraction of the dried material to filter, which is undesirable.

Finally, document WO-A-97/02222 discloses an installation for drying animal excrement, comprising an enclosure whose bottom is also mobile and permeable.

This bottom is formed of several elements consisting of articulated profiles, capable of tilting simultaneously to allow the flow of a fraction of droppings.

This type of installation is satisfactory in terms of operation. However, the tilting maneuver requires significant energy consumption. The present invention aims to overcome these drawbacks.

More specifically, it aims to provide a drying installation of simple and inexpensive design, which makes it possible to efficiently dry poultry droppings using a reduced volume of air. It aims to achieve this goal by using little energy, while recovering the air used with a high degree of saturation in humidity.

Furthermore, it aims to provide an installation whose movable and breathable bottom does not have the inconveniences described above.

According to a first aspect of the invention, the latter relates to an installation for drying animal excrement, which is adapted to receive a mixture of fresh and dry excrement, the bottom of the latter being intended to retain the mixture while being permeable to air, this bottom consisting of a set of elements each capable of forming a means for retaining excrement and comprising means which make it possible, periodically, to transfer out of the enclosure and through this bottom , a fraction of dry droppings.

It is mainly characterized by the fact that said elements consist of two series of horizontal crosspieces organized in two parallel planes supeφosés, these crosspieces being arranged in such a way that the bottom does not have a solution of continuity in the vertical direction, and by the fact that said transfer means consist of at least one drawer movable horizontally between these two planes of sleepers, the longitudinal displacement of this drawer, capable of sweeping the entire surface of said bottom from one end to the other, pushing the accumulated droppings on the top of the sleepers of the lower plane, so that they fall by gravity out of the enclosure. Thus, "the permeable bottom" comprises only one type of moving part, namely the drawer (s). This greatly simplifies the structure of the enclosure and reduces the energy consumption devoted to moving the drawer.

Furthermore, according to other advantageous and non-limiting characteristics of this installation:

- side views, the sleepers are staggered, the edges of the sleepers of the upper plane partially overlapping the sleepers of the lower plane;

- the crosspieces of the upper plane are perforated; - The enclosure has two rectangular drawers, the width of which is equal to half that of the bottom, and these two drawers are movable in opposite directions;

- The actuating means of said drawers consist of a first cable which connects their transverse edges directed on the same side, this cable passing over a series of pulleys of which at least one is driving, and a second cable which connects their opposite transverse edges at the first, this cable passing over a series of deflection pulleys, so that by actuation of the driving pulley, one of the drawers moves in one direction, while the second moves in the opposite direction; - They include means capable of always putting the two strands of the first cable, respectively attached to the first and second drawers, under tension;

- It comprises a carriage movable longitudinally, capable of receiving said mixture and distributing it uniformly over said bottom; - Said carriage carries a series of fingers directed downwards, capable of equalizing the layer of mixture poured onto said bottom;

- Said series of fingers is retractable at the end of the enclosure. The invention also relates to an installation for drying animal droppings. It is essentially characterized by the fact that it includes:

- means for mixing fresh manure with dry manure;

- a drying enclosure conforming to one or other of the above characteristics; - means for blowing air into said enclosure, through said bottom.

Other characteristics and advantages of the invention will appear on reading the detailed description which follows of a preferred but non-limiting embodiment. This description will be made with reference to the accompanying drawings in which:

- Figure 1 is a very schematic presentation of an installation including an enclosure according to the invention, intended to show the various elements which compose it, the lower part of the figure being normally inscribed in the continuity of the upper part; - Figure 2 is a side view of the means which make it possible to supply the enclosure according to the invention with droppings, its bottom being cut by a longitudinal vertical plane;

- Figure 3 is a partial top view ^• of sleepers that make up the permeable bottom of the enclosure;

- Figure 4 is a simplified top view of the enclosure, with its means for supplying excrement;

- Figure 5 is a top view of the actuating means of the movable drawers which equip the enclosure; - Figure 6 is a general top view of these drawers, with their actuating cable and their return pulleys;

- Figure 7 is a detailed view of these pulleys and the actuating cable;

- Figure 8 is a side view of the carriage supplying the enclosure with droppings, equipped with a series of equalizing fingers;

- Figure 9 is a detailed view of one of these fingers, in the retracted position.

The installation shown in FIG. 1 essentially comprises a drying enclosure 1, a set of Archimedes screw conveyors 2 and 3, a conveyor for supplying fresh manure B, as well as means for blowing air A in enclosure 1.

As will be seen below, the underside of the enclosure 1 is provided with a pit 8 for receiving dry droppings S, into which plunges the upstream end of the conveyor 2 with Archimedes screw; its downstream end, which extends outside the enclosure 1, overhangs a first section 30 of a second Archimedes screw 3.

This first section has two directions of rotation, a first direction where the screw it contains directs the materials to the enclosure 1 and a second direction where the screw directs the materials in the opposite direction.

A chute 300 communicates the conveyor 2 with the section 30. The latter is also open near the chute 300, this opening being located directly above a conveyor B with a moving conveyor belt for supplying fresh manure.

Furthermore, the downstream end of the section 30 communicates with the upstream end of a second section 31, also opposite Archimedes. The direction of rotation of this screw is unique and is capable of directing the materials towards its open downstream end, opposite the first section. Thus, if the Archimedes' screws of the sections 30 and 31 are actuated in the same direction (by motor means not shown), the dry excrements taken from the pit are poured into a pile S.

In the event that the screw of the section 30 is actuated in the opposite direction, the second section is made inoperative and the conveyor B is started. An intimate mixture M of fresh and dry excrement M then takes place in the section 30 which will be directed into the enclosure 1, as will be seen below.

The drying chamber 1 has the shape of an elongated rectangular parallelepiped and is open at its top. It is provided in its upper part, near one of its longitudinal and vertical walls, with a movable conveyor belt 4, the upper and lower strands of which extend horizontally, parallel to one another.

This mat has only one direction of rotation; this direction is such that its upper strand moves from left to right, when we consider Figure 1. Its upstream end is located slightly outside the enclosure 1 and is overhung by the outside downstream of the section 30 opposite Archimedes.

As shown in Figure 4, the conveyor 4 occupies a tiny part of the width of the enclosure.

The enclosure is also provided, in its upper part, with a mobile carriage 5 in the form of a box, guided in longitudinal translation by rollers 55 bearing on guide tracks provided in the longitudinal walls of the enclosure.

This carriage is provided with a scraper blade 51 which rests on the upper side of the conveyor 4. It is also equipped with an Archimedes screw 50, with a horizontal and transverse axis of rotation, which is located in a plane located below that of the lower strand of the conveyor 4. The bottom of the bucket in which it moves is partially open.

As will be seen below, the faeces received by the conveyor 4 are scraped by the blade 51, poured into the carriage 5 and distributed over the entire width of the enclosure by the screw 50.

Electrical or electronic means, not shown, for example with a photocell, make it possible to automatically advance the carriage, as soon as the presence of droppings is detected in the Archimedes screw.

The bottom of the enclosure 1 is generally referenced 6 and is inscribed in a rect.angle. It consists of two series of crosspieces 60 and 60 ', arranged horizontally and organized in two superimposed parallel planes Pi and P ₂ . The arrangement of the crosspieces is such that the bottom 6 presents no solution of continuity in the vertical direction. In other words, this means that seen from above or from below, the bottom gives the impression of being made up of a single continuous plate. The projection of the background on a horizontal plane therefore forms a continuous surface (devoid of openings).

The cross members are generally flat, not very thick, with a rectangular section. They are for example made of metal. As shown more particularly in FIGS. 2 and 3, the crosspieces 60 of the upper plane Pi are arranged in such a way that their transverse edges 601 partially overhang the crosspieces 60 'of the lower plane P ₂ .

The crosspieces 60 of the upper plane Pi are provided with oblong openings 600, arranged transversely. The advantage of such a characteristic will be explained later in the description.

In the space which separates the two planes Pi and P ₂ of sleepers 60 and 60 'is present at least one drawer T movable horizontally. It is a thin plate, rectangular in shape, the width of which corresponds to that of the bottom. This drawer has the function, as will be seen below, of pushing the droppings which have accumulated on the crosspieces 60 ′ of the lower plane so as to evacuate them outside the enclosure.

It is able to sweep the entire surface of the bottom, from one end to the other.

In the embodiment of FIG. 6 which corresponds to a particularly advantageous solution, the enclosure is equipped with two drawers Ti and T, in the form of rectangular plates, the width of which corresponds substantially to half that of the enclosure.

These drawers are equipped with means making it possible to move them in longitudinal translation between the two planes of sleepers, one moving in one direction, while the other is moving in the opposite direction.

To do this, each drawer is attached by one of its transverse faces to the end of a first cable 92 which cooperates with a series of return pulleys which have the general reference 9.

More specifically, with reference to Figure 5, is disposed, in the longitudinal median axis of the enclosure, a master pulley 90 whose axis of rotation, arranged vertically, is driven by means of a motor not shown. It's about a grooved pulley, advantageously trapezoidal profile. This pulley is associated with two secondary pulleys 90A and 90B so that the routing of the cable 92 on these three pulleys gives it substantially the shape of the Greek letter omega (Ω). The system is also equipped with a second pair of deflection or angle pulleys 91, each being arranged substantially along the longitudinal median axis of the drawers Ti and T.

The transverse faces of the drawers, opposite to the previous ones are, in turn, connected by a second cable 93 which cooperate with a pair of deflection or angle pulleys 94 arranged along the median longitudinal axis of the drawers Tι and T ₂ .

The four angle pulleys 91 and 94 are arranged at the corners of a fictitious rectangle, along the long sides of which the drawers are caused to be moved. It is understood that the actuation of the pulley 90 in one direction or the other, will result in the displacement of the drawer T, in one direction and, simultaneously of the drawer T in the opposite direction.

In order to avoid jolts in operation, due to the fact that the cable strand 92 which corresponds to the non-drawn drawer is soft or loose, provision is made, as illustrated in FIG. 7, for the two pulleys 90A and 90B to be integral with a stirrup, itself integral with the master pulley 90.

Thus, depending on the force exerted on the cable, all of the pulleys 90, 90A and 90B are oriented in the direction of the so-called soft cable strand, to put it under tension. This system eliminates the need for continuous monitoring of the proper functioning of the system.

Of course, when the drawers Ti and T ₂ have each arrived at one end of the enclosure 1, the actuation motor of the pulley 90 is then piloted so that its direction of rotation is reversed. Limit switches can be used to do this.

Of course, the material of the cables must be chosen to be sufficiently resistant. These may, for example, be steel cables coated with plastic.

Referring to Figure 8, there is illustrated the manure supply carriage with, at its front part, a tilting vertical arm 54, the lower end of which is provided with a series of bent fingers 52 directed towards the bottom and at an angle towards the droppings. The function of these fingers is to uniformly distribute the excrement on the sleepers so as to prevent them from accumulating on the sleepers of the upper plane, to the detriment of the lower plane.

As shown in Figure 9, this finger system is provided tilting, relative to a connecting piece 53 so that, at the end of the enclosure 10, the latter retracts. This allows the carriage 5 to move to the bottom of the enclosure, without being obstructed by the fingers.

Below the bottom 6 is provided a scraper system 7 of known type, which, as will be seen below, is intended to bring back towards the pit 8 the dry excrements which have crossed the permeable bottom 6. In a particular embodiment , several scrapers can be provided.

Finally, the installation is provided with means for supplying air A originating for example from a livestock building located near the installation.

This air is brought from below the bottom and forced to pass through it from bottom to top, for example by means of fans N.

We will now describe how the installation and the enclosure of the invention are used, with reference to the accompanying drawings.

In a preliminary stage, a mixture of fresh excrement, for example droppings, is produced with dry droppings so as to produce a loose mixture M, permeable to air. The aim of this phase is to obtain a product that is easy to handle, unlike a mass of fresh droppings which constitutes a semi-liquid product, much more difficult to handle and treat.

To do this, the fresh droppings are conveyed by the conveyor belt B in the conveyor section 30 above. An intimate mixture of these two products takes place inside the conveyor screw and the assembly is poured onto the conveyor belt conveyor 4 provided in the upper part of the enclosure 1.

The movement of the carriage 5 with respect to the belt 4 causes the mixture to spill and transfer thereof inside the enclosure on the bottom 6. As an indication, the mixture M comprises for example around 50% by weight dry matter.

Care will have been taken, before the spill, to start the air blowing means A, so that it rises inside the enclosure 1, passing primarily through the intervals between the sleepers 60 and 60 '. A fraction of the air also flows through the openings 600 of the sleepers 60. As it progresses from the bottom to the top of the enclosure, the air becomes charged with humidity (up to approximately 95%) and gradually dries the mixture M of droppings.

It is of course the mixture layer closest to the bottom 6 which is dried first.

Periodically, the motor of the pulley 90 is actuated in such a way that the drawers Ti and T ₂ undergo a translation in opposite direction between the two planes of sleepers 60 and 60 '.

During this maneuver, the fraction of dry excrement which has accumulated on the top of the sleepers 60 'is pushed and falls by gravity to the ground present in the lower part of the enclosure.

The purpose of the presence of oblong holes 600 in the crosspieces of the upper plane Pi is to accelerate the drying up of the fraction of droppings which has accumulated therein, because in this zone, the droppings are not primarily crossed by the flow of 'air A.

Each transfer of a fraction of droppings through the permeable bottom

6 results in the creation of material cones above the crosspieces 6 of the upper plane. It is to avoid this phenomenon that equalizing fingers 52 are provided on the carriage 5. In this way, the layer of droppings on the bottom 6 is constantly equalized.

The scraper 7 is periodically actuated by a cable system, so as to transfer the dry droppings into the receiving pit 8. At this level, they are collected by the Archimedes screw conveyor 2 and transferred, either entirely in a heap S for later use, or partly mixed with a new arrival of fresh droppings.

It is obvious that this whole process is carried out continuously, fractions of dry droppings being extracted from the enclosure on a regular basis. Means allowing an automatic measurement of the humidity of the droppings can be implemented, slightly above the movable bottom. In an embodiment not shown, the drawers are formed of a frame consisting of an assembly by welding of four sections, namely two longitudinal sections and two transverse sections, the interior space which they delimit being empty.

In this case, it is the vertical faces of the two transverse sections which push the excrement which has accumulated on the lower crosspieces 60 ′ of the bottom 6. Preferably, the spacing between the two sections transverse will be chosen greater than the spacing between two neighboring sleepers. For example, it can be 75 cm, the spacing between two crosspieces being 50 cm. In this way, when one of the profiles pushes droppings, the other is inactive, and vice versa. This allows to delimit the power necessary to move the drawers.

In the event that the width of the drawers is two meters, each profile moves, each time it "sweeps" a cross member, an area of approximately 1 m ² of droppings (0.5 mx 2 m).

The spacing between the two transverse planes and for example of the order of 25 mm.

Consequently, the quantity of dry excrement removed with each passage of drawers is small.

The technique according to the invention therefore makes it possible to recover regularly, using simple means and consuming little energy, a regular, unimportant and uniform layer of dry droppings, that is to say within which the rate humidity is the same everywhere.

Furthermore, to carry out this work, it is necessary to develop a tensile force on the cable 92 of the order of 400 kg, which corresponds to a power of the order of 750 watts. In the hypothesis of a background surface of the order of 200 m ² , if it were necessary to move 200 drawers capable of each sweeping an area of one m, the corresponding power to be developed would be 150 kwatts (0.750x200) .

Finally although the present invention has been described with reference to poultry droppings, other types of droppings can also be treated.

Claims

1. Drying enclosure for animal droppings, in particular poultry droppings, which is adapted to receive a mixture (M) of fresh and dry droppings, the bottom (6) thereof being intended to retain the mixture (M) while being permeable to air (A), this bottom consisting of a set of elements (60, 60 ') each capable of forming a means for retaining excrement and comprising means (T; Ti, T ₂ ) which allow, periodically, to transfer out of the enclosure (1) and through this bottom (6), a fraction of dry excrement, characterized in that the said elements consist of two series of horizontal crosspieces (60, 60 ') organized according to two superimposed parallel planes (Pi, P ₂ ), these crosspieces (60, 60') being arranged in such a way that the bottom (6) does not present any solution of continuity in the vertical direction, and thereby that said transfer means (T; Ti, T ₂ ) consist of at least one draw r horizontally movable between these two planes (Pi, P ₂ ) of sleepers (T; Ti, T ₂ ), the longitudinal displacement of this drawer, capable of sweeping the entire surface of said bottom from one end to the other, pushing the excrement accumulated on the top of the sleepers (60 ') of the lower plane (P ₂ ), so that they fall by gravity out of the enclosure.

2. Enclosure according to claim 1, characterized in that, seen from the side, the sleepers (60, 60 ') are staggered, the edges (601) of the sleepers (60) of the upper plane (Pi) partially overlapping the sleepers (60 ') from the lower plane (P ₂ ).

3. Enclosure according to one of claims 1 or 2, characterized in that the crosspieces (60) of the upper plane (Pi) are perforated.

4. Enclosure according to one of claims 1 to 3, characterized in that it comprises two drawers (Ti, T ₂ ) whose width is equal to half that of the bottom (6), and that the two drawers (Ti, T ₂ ) are movable in opposite directions.

5. Enclosure according to claim 4, characterized in that the actuation means of said drawers (Ti, T ₂ ) consist of a first cable (92) which connects their transverse edges directed on the same side, this cable passing over a series of pulleys of which at least one (90) is driving, and a second cable (93) which connects their transverse edges opposite to the first, this cable passing over a series of deflection pulleys (94), so that by actuation of the drive pulley (90), one (Ti) of the drawers moves in one direction, while the second (T ₂ ) moves in the opposite direction.

6. Enclosure according to claim 5, characterized in that they comprise means capable of always placing the two strands of the cable (92), respectively attached to the first (Ti) and to the second drawers (T ₂ ), under tension.

7. Enclosure according to one of claims 1 to 6, characterized in that it comprises a carriage (5) movable longitudinally, able to receive said mixture (M) and distribute it uniformly on said bottom (6).

8. Enclosure according to claim 7, characterized in that said carriage (5) carries a series of fingers (52) directed downward, capable of equalizing the layer of mixture (M) poured over said bottom (6).

9. Enclosure according to claim 8, characterized in that said series of fingers (52) is retractable at the end of the enclosure (1).

10. Installation for drying animal droppings, in particular poultry droppings, characterized in that it comprises:

- Means (30) for mixing fresh droppings with dry droppings;

- a drying enclosure (1) according to one of claims 1 to

9; - means (N) for blowing air (A) into said enclosure (1), through said bottom (6).