GB2348873A - Composting device - Google Patents

Abstract

A composting device comprises a plurality of, e.g. four or six, nesting containers 2 placed in a stack one above the other. Each container has an open-structure base 4 e.g. of mesh and one or more sides of the same open structure as the base or of sheet material without openings. The sheet may be thermally-insulating. The whole device may be externally thermally-insulated, e.g. by being wrapped in a flexible sheet of thermally insulating material or it may be enclosed in a housing.

Description

COMPOSTING DEVICE This invention relates to a composting device, particularly, but not exclusively for use by an amateur gardener.

Known composting devices comprise a single container e. g. a cubical box without a base, each edge being approximately 1 metre long, or a cylindrical barrel, again with no base and having a diameter about 1 metre and a height of about 1.25 metre. A removable lid is usually provided to allow uncomposted vegetable material to be placed in the container. In some devices a door or hatch is provided adjacent the ground to allow composted material to be removed.

Often the gardener needs to fork over the material during composting to try to ensure that the composting process is even and to aerate the material.

This can be difficult to achieve in practice because of the height of the container, the weight of material to be moved and the fact that the lower material is often inaccessible. Further, it can be difficult to remove a supply of composted material through the door or hatch, not only because the door or hatch is low down, but also because the material tends to become compacted and wedged above the door or hatch, or, in other words, does not fall freely to the ground. Altematively, loose, Tess well-composted material drops down from above preventing access to the preferred compost. Either way, it is difficult to extract the whole of a well-composted lower layer of material ; a pillar is likely to be left in the middle It is an object of the present invention to provide a composting device which does not, or is less likely to, cause the aforementioned difficulties.

In accordance with the invention the composting device comprises a plurality of nesting containers, each container consisting of a base and at least one side, the base having an open structure which allows drainage and contact between vegetable material in a first container and vegetable material in a second container immediately above the first.

In use, in the composting device, each container base is preferably disposed generally horizontally, and the or each side extends upwardly from the base.

The or each side does not extend perpendicularly to the base, but at an intemal angle greater than 90 degrees e. g. about 100 degrees to allow nesting of one container inside another when the material has settled, shrunk or decomposed. Further each container may fully nest inside another when stored and not in use as a composting device.

The base of each container may be circular, oval, square, rectangular, or polygonal, every container in the device having the same shape and size.

The or each side may have the same open structure as the base, or may comprise a sheet without any openings. Further, if without openings, the sheet may be of a thermally-insulating material to conserve heat energy within the container.

Conveniently, the base may comprise wire mesh, preferably galvanise and/or painted or plastic-coated, and the or each side, if open-structured, may comprise the same material.

One embodiment of the invention will now be described by way of example, with reference to the accompanying drawings, of which: Figure 1 shows a vertical cross-section through a composting device according to the invention; Figure 2 shows a perspective view of one container of the device shown in Figure 1; Figure 3 shows a perspective view of an altemative form of container of the container shown in Figure 1; and, Figure 4 shows a vertical cross-section through six containers fully nested together for storage and not in use as a composting device.

As shown in Figure 1 the composting device 1 comprises a plurality of containers 2 each having a base 4, stacked one upon another with the base 4* of the lowest container on the ground G, and the bases 4 of the other containers each nesting within the container immediately beneath. Four containers are shown in Figure 1. The bases 4 of the containers 2 (other than the lowest base 4*) also rest on vegetable material V to be composted. The composting device of this embodiment comprises a lid 3 which is positioned within the uppermost container. The lid has a handle 10.

Each container of this embodiment has a square base 4, made of galvanise steel wire mesh, and four sides 5, which may be of galvanise steel sheet without any openings, as shown in Figure 2, or alternatively, of the same galvanised steel wire mesh material as the base 4, as shown by reference numeral 6 in Figure 3. A rim 7, made, for example, of relatively thick galvanise steel wire, is positioned externally at the upper edge 9 of each side 5. Each side 4 is trapezoidal, so that the length of the upper edge 9 of each side 4 is longer than a side 8 of the base 4. Thus each side extends upwardly and outwardly at an intemal angle A which is about 100 degrees to the base and is sufficient to allow full nesting of one container within another as shown in Figure 4. Conveniently the length of the side 8 of the base 4 is 600mm and the length of the upper edge 9 of a side 5 of each container 2 is approximately 650mm. The vertical height H (see Figure 1) of each container is conveniently 225 mm. The container may have other dimensions depending on the construction and configuration of the sides 5 and rim 9. The length of a side 8 of the base 4 is unlikely to exceed 900 mm., since above this the container would be difficult to handle or lift, being heavy when full of wet vegetable material, for example.

To prevent undue corrosion due to damp, rain etc., each container 2 is, in this embodiment, galvanised. Alternatively or additionally, each container may be either painted or provided with a suitable plastic coating.

The lid 3 comprises sheet steel, which is galvanise and/or painted or plastic-coated. Alternatively, the lid may be made from extemal grade plywood or from a thermally-insulating plastic such as expanded polystyrene covered with an impermeable membrane.

The containers may be located in use inside a suitable housing e. g. a cubical wooden box having internal dimensions slightly greater than the lengths of the upper edges 9 of the containers 2. If the containers are circular in plan, the housing may be cylindrical, made of e. g. moulded plastic, and having an intemal diameter slightly greater than the diameter of the upper edge of the containers. The containers may be lifted one by one into or out of the housing which, for convenience, is preferably capable of being readily dismantled and reassembled. The housing provides insulation and protection from the elements e. g. rain and wind, thus giving the gardener some control over the amount of moisture in the composting material and the composting temperature and preventing vegetable material being blown away from the device. The housing may give the device an improved appearance.

In a modification, each side is made of a sheet of thermally-insulating material e. g. expanded polystyrene covered with an impermeable membrane, in order to conserve heat which is generated during the composting process.

Alternatively, the whole device may be extemally thermally insulated, e. g. by being wrapped in a flexible sheet of thermally-insulating material In use, a container is used to collect vegetable material to be composted from its source, and then transported to the place where the composting device is to be sited. This container is placed directly on the ground so that the vegetable material is in contact with the soil. Worms or other organisms in the soil can then move into the vegetable material through the mesh openings.

This is the lowest container 2* as shown in Figure 1. When this container is full, a second container is placed on top and so on to form the composting device.

The lid 3 is placed on the vegetable material V in the uppermost container. As the vegetable material decomposes, settling occurs and each container 2 nests further inside the one beneath, except for the lowest container 2*. The lid will also move downwards as the vegetable material in the topmost container decomposes and settles.

When the composting process is complete, the lid and upper containers may be removed to reveal composted material in the lowest container (s), which can then be transported, conveniently still in the container (s), to the place where it is required. The remaining containers, containing partially composted material, are then restacked and the now empty container (s) can be refilled and placed on the top of the stack of containers in the device. The lid is then placed on top of the material in the topmost container.

There are several options available to the gardener as to how the device according to the invention may be used with advantage. These are set out in the following paragraphs.

The containers can each be lifted off at intervals, placed in a convenient position, and the vegetable material tumed over to provide aeration. The material adjacent the sides may be moved towards the centre of the container.

Layers of soil, coarse material (e. g. shredded woody material) or fine material (e. g. grass cuttings or leaves) etc. can be incorporated and/or mixed in at the gardener's discretion.

The vegetable material of one container can be mixed readily with or added to the vegetable material of another.

A composting accelerator may be added readily to the vegetable material in any one of the containers and at any time during the composting process.

The device and the vegetable material therein, may be left undisturbed for as long as required.

Instead of being placed directly on the ground, the lowest container 2*, may be placed on a suitable support which allows free circulation of air undemeath the base of the lowest container.

Each container, because of its size and shape can be usually be easily lifted and moved by hand, even if full of vegetable material. However this depends on the overall size of a container and the particular materiat inside. For example wet grass and/or compacted grass cuttings can be very heavy, and two people are required to lift a container in this situation.

Fully composted material can be removed readily from the containers at the bottom of the device and partially composted material in upper containers left until fully composted.

The gardener can readily inspect the vegetable material in any container and at any time to see how the composting process is proceeding, or how much composted material is available.

It is easy to fork over or mix vegetable material in any container as required, and/or to add accelerator, if required.

The composting device according to the invention can be used to compost vegetable material aerobically or anaerobically.

Claims (15)

1. CLAIMS :- 1. A composting device comprising a plurality of nesting containers, each container consisting of a base and at least one side, the base having an open structure which allows drainage and contact between vegetable material in a first container and vegetable material in a second container immediately above the first.
2. 2. A composting device according to claim 1 wherein, in use, each container base is disposed generally horizontal.
3. 3. A composting device according to claim 2 wherein the or each side extends upwardly from the base.
4. 4. A composting device according to any one of the preceding claims wherein the or each side extends upwardly from the base at an internal angle greater than 90 degrees.
5. 5. A composting device according to claim 4 wherein the intemal angle is about 100 degrees.
6. 6. A composting device according to any one of the preceding claims wherein the base of each container is square, rectangular, circular, oval, or polygonal.
7. 7. A composting device according to any one of the preceding claims wherein the or each side has the same open structure as the base.
8. 8. A composting device according to any one of claims 1-6 wherein the or each side comprises a sheet without any openings.
9. 9. A composting device according to claim 8 wherein the sheet is of thermally insulating material.
10. 10. A composting device according to any one of the preceding claims comprising a lid.
11. 11. A composting device substantially as described herein with reference to, and as illustrated in, Figures 1,2 and 4 of the accompanying drawings.
12. 12. A composting device substantially as described herein with reference to, and as illustrated in, Figures 1,3 and 4 of the accompanying drawings.
13. 13. A composting device according to any one of the preceding claims which is externally thermally insulated.
14. 14. A composting device according to any one of claims 1 to 12 comprising a housing within which the containers are located in use.
15. 15. A composting device according to claim 14 wherein the housing is capable of being dismantled and reassembled.