CA2036555A1

CA2036555A1 - Mobile composting bin

Info

Publication number: CA2036555A1
Application number: CA002036555A
Authority: CA
Inventors: Lothar Dolle; Friedel Vollmer; Karl Strobach
Original assignee: Mannesmann AG
Current assignee: Vodafone GmbH
Priority date: 1990-02-19
Filing date: 1991-02-18
Publication date: 1991-08-20
Also published as: EP0444334A3; ATE94859T1; DE59002851D1; DE4005534C1; EP0444334B1; ES2044421T3; DK0444334T3; EP0444334A2

Abstract

Mobile compost bin Abstract The present invention relates to a mobile compost bin (1) in a closed container form (cube shape) comprising connections (2) for supplying and carrying off air for the decomposition pro-cess, a double bottom (3) formed from a continuous lower bottom plate (4) and a perforated plate (5) arranged above it, a sewer pipe from the hollow space of the double bottom (3) and at least one loading hatch (6) in the top of the compost bin (1) as well as at least one unloading hatch (7) in a side wall of this bin (1).
To improve a compost bin of this kind so that the usual disadvant-ages are avoided and so that it is easy to empty and clean, it is proposed that the perforated plate be configured from a plurality of U-profiles (8) which, with their centre struts (9) lying on top, are arranged close beside one another and have air holes (11) worked in the centre webs (9), and that the U-profiles (8), their longitudinal axis pointing in the direction of the unloading hatch (7), be loosely supported by their side webs (10) on cross girders (12) of the double bottom (3).

Description

2036~55 The present invention relates to a mobile compost bin in a closed container form.
In modern waste management planning, such compost bins fulfill an important function with respec-t to the necessity of utili~ing fermentable organic waste. The container-shaped (cube-shaped) cons-truction of these compost bins, permitting easy hand-ling of the compost material, is of particular advantage since these bins can be stacked not only if required for the period of the decomposition process and thus -take up Little space, but can also be moved and emptied by means of various lifting and trans-port systems (e.g. dump truck, crane runway, bridge crane, con-tainer crane, etc.).
Compost bins of a compost construction, which is known from WLB 5 (1989~, page 53, are loaded through a loading hatch in the top of the container, the hatch being fastened on ore side with hinges, and are unloaded through a swing-out unloading hatch on a narrow side of the container.
The connecting pieces for supplying and carrying off the air required for rapid composting are also arranged in the area of the unloading hatch. The bottom of the compost bin is designed as a double bottom, the upper part of which is a continuous bottom plate (perforated plate) with circular air holes. This perforated plate is tightly connected to the container. The edges of the air holes are sharp. The hollow space below the perforated plate communicates with one of the air connecting pieces for supplying or carrying off the air.
When air is circulated from top to bottom, condensation 20~6~

water, and possiDly also seepage water, collects on the lower bottom plate in the hollow space below -the perforated plate. This condensation water gets into the pipe of the air hole and must be removed from there, necessitating appropriate manual intervention.
The permanently welded perforated plate constitutes a further dis-advantage of the known compost bins since replacement in the event of repair is very expensive. Furthermore, problems occasion ally arise when emptying the container, which can as such be carried out very simply by tilting the container, for example by means of a container crane, whereby the compost slides out of the unloading hatch. In this connection it can happen that the compost sticks to tne perforated plate and to the side walls because the container cannot be tilted far enough. Inclination to the hori-zontal is often restricted to about 45. Moreover, cleaning a compost bin after it is emptied in order to prepare it for the next use is occasionally complicated. Cleaning is carried out by rinsing the tilted container witn water. Removal, if required of the compost scrap that fell into the holLow space of the double bottom is difficult.
Finally, it is also a disadvantage that air cannot flow through the perforated plate at points at which this plate is placed on cross giraers to guarantee an adequate load-carrying capacity and to prevent buckling, since the air hoLes are covered by the cross girders.
It is therefore the object of the present invention to improve a compost bin such that these disadvantages are to a large extent avoided. In particular, it should be easy to e~pty and 2036~

clean the compost bin.
The invention provides a mobile compost bin in a closed container form comprising connections for supplying and carrying off air for the decomposition process, a double bottom formed from a continuous lower bottom plate and a perforated plate arranged above it, a drainage pipe from the hollow space of the double bottom, at least one loading hatch in the top of the compost bin and as at least one unloading hatch in a side wall of this bin, said perforated plate being configured from a plurality of inverted U-profiles having webs arranged in closely adjacent co-planar disposition, said web~ including air holes therein and said U-profiles having longitudinal axes extending towards the unload-ing hatch and having flanges that are loosely supported by on cross girders in said double bottom (3).
The present invention will be described in greater de-tail herebelow on the basis of the compost bin illustrated in the accompanying drawings wherein:
Figure 1 is a side view of a compost bin, Figure 2 is a top view of a perforated plate, Figure 3 is a longitudinal section through the compost bin, Figure 4 is a cross-section through the compost bin, Figure 5 is an enlarged top view of a perforated plate/U-profile, Figure 6 is a cross-section through a perforated plate/
~-profile, and Figure 7 is a partial sec-tion in the area of the unload-

2~36~

ing 'hatch.
The mobile compost bin illustrated in Figure 1 is con-structed of torsion-resistant section steel/steel plate and is provided all around wit`h a 40 mm thick insulation with galvanized sheet steel jacket (not shown) for thermal and low temperature insulation. Rollers are attached to the bottom 3 so that it can be transported as a roll-off container, for example by means of a winch truck. The rollers can of course be dispensed with for crane transport with a spreader. As can be seen in Figures 3 and 4, the bottom 3 is designed as a double 'bottom, i.e. a continuous bottom plate 4 is provided at the bottom and a perforated plate 5 is arranyed at a distance above it. A hollow space, through which the air required for rapid composting can be supplied or carried off, is formed between the bottom plate 4 and the perforated plate 5. This hollow space is therefore in communication with the con-nection piece 2 for supplying or carrying off air. A second air connection piece, not illustrated, is arranged at the same level as the connection piece 2 and communicates with the upper part of the container interior. T'he compost bin 1 i5 loaded through a loading hatch 6 that can be raised (Figure 4) and is unloaded through a swing-out unloading hatch 7 (Figure I). Manual or motor operated locking mechanisms are provided to open and hermetically seal the hatches 6, 7.
As is iLlustrated in Figures 2, 3 and 4, the perforated plate 5 comprises a plurality of U-profiles 8 whic'h are arranged close beside one another and are loosely supported on cross gird-ers 12. These cross girder~ 12 are permanently welded at a dis-2~3~5 tance from the lower 'bottom plate 4 by means of supports 13. As is indicated in Figure 2 and as can be clearly seen in Figures 5 and 6, the U-profiles 8 have numerous air holes 11 in their centre webs 9 for aeration of the organic material to be composted. T'he flanges 10 (Figure 7) of the U-profiles 8 are supported on the cross girders 12 and t'he longitudinal axis of these U-profiles points in the direction of t'he unloading hatch 7.
A number of advantages are achieved by means of this arrangement. On the one hand, air can flow to the full extent through the centre webs 9 via the air holes ll, i.e. there are no points at which the air holes ll are blocked by the support of a cross girder 12, as is the case with the known compost bin with a continuous perforated plate. Therefore, more effective and more uniform composting is possible with the U-profiles 8 arranged endwise. On the ot'ner hand, the loose support of the U-profiles allows the hollow space in the double bottom 3 to be uncovered quickly without any connections having to be loosened for this purpose. Cleaning this area of the compost bin 1 is thus simpli-fied quite considerably and it is also possible to replace the U~profiles without difficulty. Because the u-profiles 8 can be easily replaced, they are advisably manufactured as expendable parts from inexpensive structural steel. Thus, no high-grade, corrosion-proof materials need be used. A further advantage emerges from the shape of the U-profiles 8 since they have a high static strength (flexural strength) even with a low wall thickness and thus require comparatively little support through the cross girders. Moreover, the orientation of the longitudinal axis of ~036~

the u-profiles 8 makes it easy for the compost to slide out smoo-thly when emptying the compost bin 1.
The U-profiles 8 are advisably secured separately so that they cannot likewise slide out when emptying the bin. No screw or clamping connections or the like are necessary for this purpose; rather, as can be seen from Figure 7, it is sufficient to provide an L-shaped cross girder 15 on which the U-profiles 8 abut in the area of the unloading hatch 7.
A furt'ner advantageous embodiment lies in providing the air holes 11 with rounded, preferably downwardly (to the hollow space of the double bot-tom 3) flanged edges 16 (Figure 6) so that the sliding surface on the perforated plate 5 is as smooth as possible. Holes with sharp edges impede the emptying process.
A further improvement in the emptying of the bin results when the air holes 11 are designed as elongated holes (Figure 5), their longitudinal axis extending in the direction of the longitu-dinal axis of the profile 8. Elongated holes with a width of about 8 - 10 mm and a length of 20 - 25 mm have proven advanta-geous. Moreover, it is oftentimes advantageous for the perforated plate 5 to slope towards the unloading hatch 7. However, this incline should be less than 5, preferably less than 3 (in parti-cular, about 1.5~) to the horizontal so that the useful volume of the compost bin 1 is not reduced too much. The idea of this incline is that sufficient inclination of the perforated plate 5 can still be achieved when the compost bin 1 is tilted if the bin 1 itself cannot as such be tilted far enough. The degree of incl:ne that is otherwise missing is often only in the range of 1 203~

to 2.
In a further advantageous embodiment of the present invention the side walLs 17, 18 on the long side of the compost bin 1 are slightly divergent in the direction towards the unload-ing hatch 7, that is their distance from one another increases.
This likewise simplifies emptying of the compost bin 1. To this end, an incline to the longitudinal axis of the compost bin of less than 1, in particular of about 0.5. is often times suffi-cient.
To facilitate removal of seepage water and condensation water from the compost bin 1, it is recommended that a drainage channel 14 (Figure 3, 7), which ends in a drain connection piece (not illustrated), be provided in the lower bottom plate 4 of the double bottom 3 at an outer surface of the compost bin 1, prefer-ably in the area of the unloading hatch 7. In order to collect the water in the channel 14, the lower bottom plate 4 need not be inclined compared to the outer support points of the compost bin 1 that is set down since the compost bin can from -the start be set down on a site with a suitable incline.
Since the cross girders in a further advantageous embodiment of the present invention are merely supported on the supports 13 on the bottom plate 4 of the compost bin 1, the water can flow virtually unimpeded in the channel 14. The drain connec-tion pieces are advisably equipped with a 3-way valve so that a drainage line from the, for example siphon-Like, pipe connection for supplying and carrying off air into or from the upper region of the compost bin 1 can also be connected to the drain connection 203655~

pieces without thereby reducing the circulation of air, since the air can directly enter the siphon of the exhaust air duct via the pipe connection of the channel 14, for example when compressed air is supplied to the hollow space of the double bottom 3. In such a case, the connection of the channel 14 would be blocked by the

3-way valve and only the drainage connection for the siphon of the exhaust air duct 2 would be open. In any case, no condensate would precipitate in the hollow space of the double bottom 3 with air supplied in this direction.
The compost bin l designed in accordance with the pres-ent invention per,nits, particularly by means of its novel perfor-ated plate, empt~ing and cleaning to be carried out without diffi-culty and, in the event of repair, also permits simple replacement of damaged parts of the perforated plate. Since the air holes 11 can be manufactured from the start with flanged edyes by means of an appropriate press tool, manufacture of the U-profiles does not involve great expense.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A mobile compost bin in a closed container form compris-ing: connections for supplying and carrying off air for the de-composition process, a double bottom formed from a continuous lower bottom plate and a perforated plate arranged above it, a drainage pipe from the hollow space of the double bottom, at least one loading hatch in the top of the compost bin and as at least one unloading hatch in a side wall of this bin, said perforated plate being configured from a plurality of inverted U-profiles having webs arranged in closely adjacent co-planar disposition, said webs including air holes therein and said U-profiles having longitudinal axes extending towards the unloading hatch and having flanges that are loosely supported by on cross girders in said double bottom.

2. A compost bin according to claim 1, wherein the air holes have rounded edges.

3. A compost bin according to claim 2, wherein the air holes have a flanged edge at the lower side of the U-profile web.

4. A compost bin according to claim 2, wherein the air holes are elongated and have longitudinal axes extending in the direction of the unloading hatch.

5. A compost bin according to any of claims 1 to 4, wherein the perforated plate is inclined downwardly in the direction of the unloading hatch.

6. A compost bin according to claim 5, wherein the incline is less than 3°.

7. A compost bin according to any of claims 1 to 4 or 6 wherein the u-profiles are configured from simple structural steel.

8. A compost bin according to any of claims 1 to 4 or 6 wherein the U-profiles are secured against sliding out of the unloading hatch.

9. A compost bin according to any of claims 1 to 4 or 6 wherein the cross girders are fastened to supports spaced above the lower bottom plate, and a drain channel, which can be emptied by means of a separate drain connection piece, is arranged in the lower bottom plate of the double bottom at an outer surface.

10. A compost bin according to any of claims 1 to 4 or 6 wherein the distance of the side walls from one another increases in the direction towards the unloading hatch.