SE506488C2 - Method and apparatus for decomposing materials to be composted - Google Patents

Abstract

A method and an apparatus for preparation of household waste before final composting, wherein the waste is disintegrated and compressed in a treatment shaft by forcing the waste past disintegrating knives with the aid of scissors knives arranged on a driven piston, whereby the disintegrating knives are arranged with a mutual spacing which determines the disintegrating rate and whereby the scissors knives are arranged on the piston so that they fit into said spacings.

Description

506 488 2 intended to be placed in e.g. an apartment building, and is characterized by an feed shaft, a substantially horizontal shaft comprising disintegration knives arranged at intervals of the upper shaft at the discharge end of the shaft as well as a reciprocating slide working in the shaft to push the waste past the disintegration manifold. substantially horizontal shaft is connected to the feed shaft via an opening in the upper boundary wall of the horizontal shaft and that a means is provided for cutting off waste standing in the feed shaft and for closing and opening said opening during compression and compression of the waste.

Additional features of the compost processor according to the invention appear from claims 5 - 16.

The compost processor according to the present invention has a very compact construction, where the waste is handled completely in an enclosed space without anyone coming into contact with it after the decomposition and with the least possible odor load. The at least partially decomposed waste can be transported further in the collection vessel for final composting or the vessel can be replaced with a larger container, e.g. 3 m3 container depending on how many apartments the facility is to serve.

Furthermore, the method and the device are particularly well suited for automation.

The construction according to the invention means that material does not remain in the disintegration device. In combination with suitably designed disintegration knives, a very efficient disintegration of the material is achieved and compost bags do not offer any problem either, instead it is achieved with a suitable choice of compost bags that the amount of litter material that must normally be added can be reduced or even omitted. This in combination with a closed collection vessel for the composting process provides a complete system that can be largely automated and which provides a very smooth handling of the waste.

According to a preferred embodiment of the invention, a transport device is airtightly connected to the compaction part of the mechanical processing device, by means of which the prepared waste is transferred to collection vessels.

According to a further development of the plant according to the invention, a valve bottom is arranged in the collecting vessel and is connected to air supply means for air supply during the collected prepared waste in order to promote aerobic decomposition. Description of the invention Additional advantages, objects and features of the invention will become apparent from the following detailed description of exemplary embodiments of the invention taken in conjunction with the accompanying drawings in which Fig. 1 schematically shows a cross section through a compost mixer; Fig. 2 shows on an enlarged scale a longitudinal section through the waste preparation device, Fig. 3 shows a cross section taken along the line III-III in Fig. 2, Fig. 4 shows an end view taken in the direction of the arrows IV-IV in Fig. 2: Fig. 5 shows a cross-section through an embodiment of the waste decomposition and compaction part of the processor, and Fig. 6 shows a cross-section taken along the line VI-VI in Fig. 5.

Detailed description The invention will now be described in connection with the compost processor shown diagrammatically in Fig. 1, but of course changes and modifications can be made without departing from the spirit of the invention.

The compost processor according to the invention is particularly intended for placement in apartment buildings where the spaces are generally limited and where the requirements for minimal odor and low noise level are high. As will be apparent from the following description, the mail processor according to the invention can be made very compact, and it has a pallet size (80 x 120 cm) and is conveniently moved by means of a conventional pallet truck. It also works very quietly and can be made practically odorless.

For obvious reasons, household waste is usually handled and transported in bags, which are carried to the processor and thrown into it.

By using bags made of paper or equivalent degradable material, the otherwise necessary material for composting can be significantly reduced or possibly even omitted. 506 488 4 Waste bags 1 are thrown into the boiler through a hatch 2 in an input shaft 3. The hatch is only indicated as an opening, but should be tight-fitting, and preferably of the "bankbox" type to reduce the risk of tampering. In the upper part of the shaft there is suitably a ventilation, indicated by the pipe 4, possibly provided with a fan to generate negative pressure in the system and eliminate odor shocks when the door is opened. The fan can be controlled by the opening movement of the door or operated continuously. The system can also be operated on existing ventilation.

A feed material supply device 5 is shown in connection with the feed shaft with feed material container 6, dosing piston 7 as well as a driving hydraulically controlled piston-cylinder device 8. Depending on the composition of the waste, feed material can be completely excluded under favorable circumstances, which considerably simplifies handling of the device.

The waste bags fall through the feed shaft into a substantially horizontal shaft 9 through an opening 10 therein.

The waste is pressed against a set of knives 11 next to one end of the horizontal shaft by a preferably hydraulically driven slide 14. Above the slide is arranged a hatch 15 which cooperates with a knife 16 in the front edge of the opening 10. The door actuator has been omitted for clarity. The door is arranged to move with the movement of the slide but offset in relation to this. During a disintegration and compaction step, the door is moved forward so that its leading, sharp edge cuts off debris standing in the vertical feed shaft and at the same time closes the opening. When the slide returns, the door follows as soon as the slide has left the area under the opening in the horizontal shaft.

The slide 14 is designed and guided to move back and forth against the knife set 11, formed with vertical disintegration knives arranged at intervals, which determine the size of the disintegrated waste. The design of the disintegration knives as well as the design of the slide will be described in more detail below in connection with Figs. 3 - 6.

Compression of the waste takes place during passage through the set of knives and further compaction is achieved in the compaction space 19 which lies after the set of knives seen in the direction of movement of the waste. During compaction, moisture is forced out of the waste which can be discharged as 506,488 leachate through an outlet 20 in the compaction chamber. By arranging the substantially horizontal shaft slightly inclined forwards, it is avoided that such odorous water accumulates in the rear parts of the shaft where it can give rise to odors and damage.

Adjacent to the compaction chamber 19 is arranged a transport pipe 21. The disintegrated and compressed waste is transported in a compressed state by a waste pump 22 with piston 23 which gradually feeds the waste and thereby exposes the compaction space. The piston 11 can then "pick up" the next batch of waste. During the disintegration and compression phase, the compression space is suitably closed upwards by a piston-operated slide 24 and downwards by the pump piston 23 or other means. Due to the intermittent feeding of the waste through the transport pipe, the residence time of the waste in this can be long. The decomposition of the waste proceeds continuously and in order to avoid anaerobic decomposition, it is essential to add oxygen. This takes place in several places along the transport pipe, which is indicated by compressed air supply lines 25 a - d, which are fed via a line 25 from a compressed air source 26.

The invention is not limited to the mode of transport described above, but this can also be done by means of e.g. a screw working in the transport pipe.

When the waste leaves the tube and is pressed into a collecting vessel 30, it is compressed. In order to atomize the waste and at the same time avoid it settling in a pile in the vessel, a rotor 27 with arms 28 or the like arranged by a motor 29 is arranged next to the mouth of the pipe and which again atomizes the waste and spreads it in the collection container so that it ends up airy. and well distributed therein.

In addition, air or another oxygen carrier is supplied at the bottom of the container, e.g. via a tube 31 with nozzles 32 distributed over its length, whereby the composting / decomposition proceeds during the residence time in the container. Compressed air is supplied from compressed air source 26 via pipeline 33. However, the idea is that when the container is filled, final composting should take place elsewhere.

To facilitate handling, according to the preferred embodiment, the rotor 27 with drive motor 29 and associated connections is mounted on the collection container lid 34, which can then be easily lifted off the container and placed on an empty container or put back on the container after emptying it. The transport pipe 21 as well as the ventilation 35 are also connected via sockets or the like in the lid 34 or in a disc which is mounted in an opening in the lid, if applicable.

A pre-composting thus takes place in the waste container 30, but since it is impractical to arrange containers which are large enough to allow final composting of all compost waste from an apartment building in connection therewith, it is suitable that containers of a manageable size are used, which then emptied regularly to carry out the final composting elsewhere.

Fig. 2 shows a cross section through an embodiment of the processing device itself. The horizontal shaft 9 has a rectangular cross-section and consists of an inner sheet metal shell 40 cast in an outer concrete shell 41. This eliminates the risk of leakage in welded joints while the construction becomes very stable and can easily withstand the large loads that occur when the boiler working. A suitable compressive force is estimated to be about 10 tonnes, which, however, also depends on the design of the knives.

The slide 14 is substantially box-shaped and thereby obtains good control in the shaft. The door 15, which is shown in Fig. 2 covering the opening 10, has a front cutting edge which cooperates with the knife 16 at the edge of the door opening 10. This effectively prevents waste from being trapped between the shaft wall and the slide.

Fig. 3 shows an example of the attachment of the knife 16 in front of the wall of the feed shaft.

Fig. 4 schematically shows an easily removable knife set 11 mounted in a mounting plate 42. The exact design of the knives 43 depends on the composition of the waste, or rather the discipline of the users. If e.g. glassware, cutlery and other hard objects regularly end up among the household waste, the wear on the knives becomes great. The gaps 44 between the knives determine the degree of atomization of the prepared waste.

Another problem that can arise is that the waste is packaged in plastic bags despite the recommendation to use particularly appropriate waste bags made of paper or cardboard. The plastic is tough and can withstand the slide's efforts to push the waste through the knife set. 506 488 7 This problem can be eliminated by arranging special tearing means in the feed shaft, on the slide or in another suitable way.

In the embodiment exemplified above, the intention is for the slide to press the waste through the decomposition knife set. The knife set is arranged at the end of a shaft, and this enables the slide to perform several strokes for each "set" of waste dropped into the horizontal shaft.

In order for the device to work well even when cardboard, plastic and sheet metal end up in the compost waste, the device has been further developed as shown in Figs. 5 and 6.

Fig. 5 shows a cross-sectional view of an alternative embodiment of the device according to the invention. Disassembly knives 50 are arranged in line with the front edge of the feed opening at intervals 51. On the front end of the slide 14 are arranged scissor knives 52 so distributed and arranged that they can pass into the spaces between the disintegration knives 50. Between the scissor knives 52 are arranged cleaning means 53, for example in the form of freely movable lattice-shaped elements. During the forward movement of the slide, the cleaners are dragged into the movement. During the return movement, the movement of the cleaning means is slowed down or prevented before the slide reaches its longest retracted position. This can be done by friction, arranging stop lugs, etc. When the cleaning means are braked or stopped, they clean the spaces between the scissor knives 52 from e.g. cardboard and plastic that like to get stuck between the scissor knives.

According to a preferred embodiment, the scissor knives are designed to be of different lengths, so that the longest knife or knives lie in the middle and so that the knife lengths then decrease towards the edges. In this way, the waste decomposition takes place in stages over the cross-section, which leads to the energy consumption in the press torque being reduced.

Fig. 6 shows a side cross-sectional view of the embodiment in fig.

. Also according to the preferred embodiment, the scissor blades 52 edges 60 are obliquely cut. This achieves a significantly improved cutting effect, and also sheet metal that has ended up in the compost waste is decomposed efficiently.

Claims (7)

1. 0 15 20 25 30 35 506 488 PATENT REQUIREMENTS 1. Methods of preparing household waste for final composting, where the waste is decomposed and compressed in a substantially horizontal processing shaft by means of scissor knives arranged on a driven piston, which are caused to push the waste past at an outlet end at the machining shaft fixedly arranged disintegration knives. 2. Compost preparer for the preparation of household waste for composting intended to be placed e.g. in connection with multi-dwelling buildings, containing an input shaft, an adjoining, substantially horizontal processing shaft, a transport device connected to an output end of the processing shaft and a subsequent, aerated intermediate storage container for the processed waste, a coal-driven processing unit disintegrating knives, arranged spaced across the cross-section of the preparation shaft near its discharge end, and scissor knives on the side of the piston facing the discharge end arranged so that they can pass into and out of the spaces between the disintegrating knives arranged in the shaft. Compost mixer according to Claim 2, characterized in that the scissor blades are of mutually different lengths. Compost processor according to Claim 2, characterized in that the scissor blades are furthest in the middle area of the slide and that their resp. length decreases towards the edges. Compost processor according to one of Claims 2 to 4, characterized in that the scissor blades are slanted. Compost processor according to one of Claims 2 to 5, characterized by cleaning means arranged to clean the spaces between the scissor blades in the retracted position of the piston. Compost processor according to one of Claims 2 to 6, characterized by a compression chamber arranged after the disintegration knives for waste disintegrated by means of the knives. Compost processor according to claim 2, characterized in that the transport device consists of a transport pipe comprising air supply means as well as a screw conveyor rotating in the pipe. Compost processor according to claim 2, characterized in that the collection container comprises means for air supply in the prepared waste as well as a disintegration and spreading device near the mouth of the transport pipe in the collection container.