FR2767818A1 - Composting installation with integral mixer - Google Patents

Abstract

Material for composting is laid out in long swaths between parallel walls (10). The material is spread and periodically turned, aerated and mixed by a dedicated turner (3) which moves back and forth along the swaths on a chariot resting on top of the walls. The turner is one or more horizontal drums, carrying a number of approximately radial fingers (30 and 30'). The drum can rotate clockwise or anticlockwise for spreading material or turning

Description

COMPOSTING INSTALLATION
The present invention relates to a solid substrate composting installation alone or using liquid effluent.

 By "solid substrate" is meant any solid carbon source material capable of being transformed by aerobic fermentation. As an example, we can cite straw, manure, green waste (cut lawn, branches), sawdust, wood, etc. This expression also includes materials that need to receive a liquid effluent to transform (sawdust, wood) than those which degrade alone, without external input (manure, green waste such as leaves).

 By the expression "liquid effluent" is meant any effluent supplying mineral matter, in particular nitrogen, capable of degrading by aerobic fermentation, when it is combined with a solid substrate. One can cite, for example, slurry, industrial and viticultural effluents, urban sludge, etc.

 Increasingly stringent environmental measures, as well as the increase in animal husbandry, have given rise to a good number of composting processes and installations.

 One of the simplest techniques is to place the substrate, especially straw, on the ground in a long pile called a swath. An effluent, in particular manure, is injected into the swath to start the degradation process. From time to time, another tractor on which is provided a swath turner suitable for mixing, brewing and aerating the straw, is moved along the pile. Such treatment is necessary for aerobic fermentation to take place within the substrate.

 This technique has proven itself and is satisfactory. However, it requires at least one towing vehicle to which it is necessary to attach the appropriate equipment.

 If this poses little problem when the volume of material to be treated is small, it becomes troublesome when we are dealing with large volumes which occupy the vehicle almost permanently. In addition, a large amount of energy is expended when brewing the material using the swath turner. Finally, this material is only provided for one direction of rotation, so that it is necessary each time to carry out tedious maneuvers to carry out a new reversal.

 Document FR - B - 2 728 891 in the name of the applicant relates to a composting installation which includes a circular area with a downward slope towards its center. The gutter for recovering excess effluent is provided in the central region of the area. At this location are also located the means of supplying the effluent.

Again, it is necessary to have available a tractor to mix and periodically aerate the substrate / effluent mixture.
The present invention aims to overcome these drawbacks.

 In other words, it aims to offer a composting facility that does not require any outside machine capable of being used for other tasks.

 It also aims to provide an automated installation and, in so doing, allowing a larger volume of substrate to be treated than the installations known up to now.

 Finally, it aims to provide a simple installation, economical and easy to operate.

 The installation in question comprises an area for receiving said substrate, possibly means for supplying and distributing the effluent on this substrate, as well as means for stirring and aerating the latter.

 According to the invention, it is characterized by the fact that said area is delimited laterally by two parallel low walls, that it comprises a carriage movable longitudinally, which overhangs the area by bearing on the top of said low walls, and that said means of stirring and ventilation comprise at least one transverse rotor of substantially horizontal axis carried by the mobile carriage, this rotor comprising means capable of stirring the substrate when it is rotated.

 Thus, the carriage and the associated rotor that the installation comprises are used exclusively for the treatment of the substrate, without requiring any additional external material.

Furthermore, according to other advantageous features of the invention:
- The means capable of brewing the substrate are also capable of disentangling the substrate when it is compacted;
- Said carriage comprises means capable of permitting its displacement alternately in the two opposite directions, along said walls;
- Said rotor has two directions of rotation;
- The means which equip the rotor consist of articulated peripheral fingers forming flails, a number of which retracts according to the direction of rotation of the rotor;
- Said carriage carries the means for supplying and distributing the liquid effluent on the substrate, this effluent being contained in a pit adjoining the area;
- Said means consist of a pump connected on the one hand to a pipe plunging permanently into the pit and, on the other hand, to at least one distribution pipe which overhangs the area;
- It includes means for stopping the carriage at the end of the wall;
- said area is covered;
- It includes an automaton which automatically manages the movement and the speed of the carriage, the direction and the speed of rotation of the rotor, and the flow of distribution of the effluent when it is used.

Other characteristics and advantages of the invention will appear on reading the detailed description which will follow of certain preferred embodiments. This description will be made with reference to the accompanying drawings in which:
- Figure 1 is a block diagram, seen at the end, of an installation according to the invention;
- Figure 2 is a perspective view of an alternative embodiment of the installation of Figure 1, in which the means for supplying and distributing slurry have not been shown;
- Figures 3 and 4 are respectively end and front views of the installation rotor and its associated beams;
- Figures 5 and 6 are diagrams showing the action of the rotor during the disentangling and mixing of the substrate;
- Figure 7 is a block diagram further illustrating an alternative embodiment of the installation.

 The composting installation 1 shown in FIG. 1 essentially comprises a composting area A intended to receive on the one hand the solid substrate and on the other hand the liquid effluent.

 This area is preferably formed of a flat and horizontal concrete surface and, in accordance with the invention, is delimited laterally by two parallel low walls 10. By way of indication, the low walls are 1.5 meters high and are spaced apart. one another of 4 meters. They can extend over 50 meters. Area A therefore has the shape of a long corridor delimited by the low walls 10.

 The ends of the "corridor" are preferably inclined downwards, so as to channel any effluent leaks towards collecting means such as gutters.

 Parallel to one of these low walls 10 extends a third wall 11. They delimit with transverse end walls 12, a pit 13 adjoining area A, the function of which will be explained below.

 On the top of the walls 10 are fixed rails 100. They extend all along the area.

 They serve as a raceway for a mobile carriage which has the general reference 2. This carriage consists of an assembly of crosspieces and metal beams 21 and 24. Due to the representation seen at the end of FIG. 1, only the sleepers 21 are visible.

 This carriage, when viewed from above, has the shape of a rectangle and is fitted, near its four angles, with wheels 22 received between the wings on the rails 100 of the walls 10.

 One or more motors, not shown, for driving the wheels, make it possible to move the carriage along the walls, preferably in two opposite directions (forwards and backwards).

 Halfway across the carriage extends a vertical beam 23 which serves as a separation and a support means for the rotary shaft 31 of two rotors 3.

 By the term "rotor" is meant a generally cylindrical roller mu which rotates on itself.

 These rotors, arranged transversely and horizontally with respect to area A, are rotated on themselves by means of a universal joint transmission 40 connected to a motor 4 carried by the carriage 2.

 The motors for actuating the wheels and rotors are preferably electric and are connected to a power supply by a sliding cable (not shown) along a wall 10.

 Preferably, the rotors can be rotated either in one direction or the other.

 They carry at their periphery a series of fingers 30 and 30 'forming flails.

To facilitate reading of Figure 1, these fingers have been shown very schematically, and only in diametrically opposite arrangements. However, it is obvious that the entire surface of the rotors carries this type of finger.

 In the example shown here, two contiguous rotors 3 have been provided. This number is simply explained by the fact that the width of area A prevents the use of a rotor scul for reasons of resistance of the materials. This means that if the area were narrower, we could quite well use a single rotor 3.

 Referring to Figures 3 and 4 to view the fingers 30 and 30 'which equip the rotors.

 In practice, each rotor 3 carries at its periphery a multitude of welded irons 32, arranged radially and traversed by an opening, to which it has been attached, in an articulated manner, fingers 30 and 30 ', for example by means of bolts.

 These are curved fingers whose radius of curvature is equal to that of the rotor 3.

 For example, sixty fingers equip each rotor. They are divided into two groups of thirty, namely a group oriented upwards, and a group oriented downwards, when we consider Figure 3. Thus, when the rotor is rotated, for example in the direction of arrow f, the fingers 30 'straighten out by pivoting around the joint of the irons 32, while the fingers 30 remain flat.

 When the rotor is actuated in the opposite direction, it is the fingers 30 which become active, straightening in turn under the effect of centrifugal force.

 These fingers are intended to beat and aerate the compost that is present on the area. With a high rotational speed of the rotors, the beating generated by the fingers is sufficient to untangle the compacted substrate. This is for example the case with a bale of straw. At a lower speed, the threshing allows the aeration, the mixing of the substrate and possibly its mixing with the associated effluent when the latter is present. We will explain this in more detail later in the description.

 Figure 4 show that the fingers 30 and 30 'are not arranged according to the generatrices of the rotor but offset by a small acute angle relative to them, while being parallel to each other. This assembly is made necessary so that the substrate beaten by the plagues is pushed back sometimes on one side, sometimes on the other side of the area.

 According to the invention and according to a particular non-limiting embodiment, the mobile carriage carries means for supplying and distributing the liquid effluent on the substrate.

 These means include a pump 5 which is connected on the one hand to a pipe 50 whose lower end 51, provided with a strainer, plunges into the pit 13. It is also connected to a distribution pipe 51 which overhangs the area A and which has two branches 52 terminated by generally vertical nozzles 53.

They allow the distribution of the effluent E present in the pit, from this pit to the substrate distributed over the area. The jets of effluent at the level of area A have been represented by arrows J.

 It will be noted that the pump 5 is equipped with a regulating flow meter 9 and that the pipe 50 can be provided with a discharge nozzle, not shown, which allows the effluent E present in the pit to be stirred and homogenized correctly.

 Finally, optionally, the area A can be covered by a tunnel 70, for example made of plastic, supported on longitudinal members 7 secured to the walls 10 and 11. This tunnel makes it possible to shelter the area, so it can be used even in bad weather.

 The installation shown in FIG. 2 has an appearance similar to that already described. However, it has a narrower area A, so that a single rotor 3 can be used. The latter is driven in rotation by a motor 4, the output shaft 41 of which comprises a pulley associated with a chain 44. This chain meshes with a second pinion 43 wedged on a transverse shaft 42, which extends parallel and above the rotor 3. The ends of this shaft are also provided with a pinion associated with a chain 32 contained in a vertical plane, which is itself connected to a second pinion wedged on the axis of rotation. of the rotor 3. A casing 31 in the general shape of a "U", the wings of which extend in a vertical plane, protects the chain 32.

 Furthermore, the wheels 22 of the carriage 2 are fixed on an axis driven by a chain 80, which meshes with the pinion of the output shaft of a second motor 8.

 The operation of the installation is as follows.

 The carriage 2 being placed at one end of the area A, the substrate S to be composted is distributed thereon. It is particularly straw.

 When this substrate is supplied in compacted form, for example in the form of bundles, the movement at low speed of the carriage will be controlled in the direction of the substrate. In parallel, the motor 4 for actuating the rotor (s) will be started at high speed.

 The beating at high speed of the rotor fingers 3 against the boots B (see FIG. 5), associated with the movement of the carriage, will gradually make it possible to untangle the substrate S and to constitute a swath of unpacked, untangled and aerated product. In FIG. 5, the direction of advance of the carriage has been referenced g, while the direction of rotation of the rotors 3 has been referenced f.

 It is of course possible to spread the unpacked substrate S from the start on the area.

 When the entire area is swept for the first time in one direction, limit switches program its stop at the end of the wall.

 The movement of the carriage is then piloted in the opposite direction so as to sweep the area again. Simultaneously, the rotor (s) is (are) actuated (s) in the opposite direction and at slower speed. The pump 5 is then started, so that the jets J of effluent, for example slurry, fall in rain on the substrate.

 The mixing and aeration of the substrate, combined with the watering of the substrate will help start the composting process.

 Thereafter, the movements of the cart and the effluent sprinklers will be chosen according to the progress of the composting.

 These parameters, as well as the direction and the speed of rotation of the rotor (s) 3, can be managed if necessary by an automatic machine, possibly connected to means for analyzing the progress of composting.

 In this way, the operation of the installation can be completely automated, which makes it possible to process large volumes of substrate.

 The entire substrate on the surface degrades in a uniform manner, so that the compost obtained can be removed at once.

 Of course, when the substrate is able to transform on its own, without adding additional effluent, there is no need to start the pump 5. This is particularly the case when the substrate consists of manure or green waste.

In the embodiment of Figure 7, two parallel areas are provided
A1 and A2 separated by an effluent pit. In such a case, it is possible to sweep area A1 using the trolley, then after turning around half a turn, to sweep area A2.

As an indication, the following parameters are indicated, which are characteristic of an installation in accordance with the invention:
- rotation speed of rotor (s) 3: adjustable from 0 to 500 revolutions / minute
- advancement speed of carriage 2: from 0 to 1 meter / minute;
- pump 5 flow: from 0 to 100 m3 / hour.

Claims (9)

 1. Installation for composting solid substrate (S) alone or using liquid effluent (E), which comprises a receiving area (A) of said substrate, possibly means for supplying and distributing the effluent (E) on this substrate (S), as well as stirring and aeration of the latter,  characterized by the fact that said area (A) is delimited laterally by two parallel low walls (10), that it comprises a movable carriage (2) longitudinally, which overhangs the area (A) by bearing on the top of said low walls ( 10), and that said stirring and aeration means comprise at least one transverse rotor of substantially horizontal axis (3) carried by the movable carriage (2), this rotor (3) comprising means (30, 30 ') able to stir the substrate (S) when it is rotated.  2. Installation according to claim 1, characterized in that the means (30, 30 ') capable of mixing the substrate (S) are also capable of disentangling the substrate (S) when it is compacted.  3. Installation according to claim 1 or 2, characterized in that said carriage (2) comprises means capable of allowing its movement alternately in two opposite directions, along said walls (10).  4. Installation according to claim 3, characterized in that said rotor (3) is in two directions of rotation.  5. Installation according to claim 4, characterized in that the means which equip the rotor (3) are peripheral fingers (30, 30 ') articulated forming flails, a number of which retracts according to the direction of rotation of the rotor (3).  6. Installation according to one of claims 1 to 5, characterized in that said carriage (2) carries the means for supplying and distributing the liquid effluent (E) on the substrate (S), this effluent ( E) being contained in a pit (13) adjacent to the area (A).  7. Installation according to claim 6, characterized in that said means consist of a pump (4) connected on the one hand to a pipe (50) plunging permanently into the pit (13) and, on the other hand to at minus a distribution pipe (51, 52) which overhangs the area (A).  8. Installation according to one of claims 1 to 7, characterized in that it comprises means for stopping the carriage (2) at the end of the wall (10).  i O. Installation according to one of claims 1 to 9, characterized in that it comprises an automaton which automatically manages the movement and the speed of the carriage (2), the direction and the speed of rotation of the rotor (3) , as well as the flow rate of the effluent (E) when it is used.  9. Installation according to one of claims 1 to 8, characterized in that said area (A) is covered.