The importance of reducing the quantity of organic wastes discarded by the average household has become recognized more acutely in recent years as waste disposal facilities available to municipalities and other urban districts have become more limited. One of the simplest and cheapest ways to dispose of household organic waste is to allow it to degrade into compost, which can then be incorporated into the soil to enhance the growing characteristics thereof. Indeed, the traditional compost heap is a familiar feature of the yard of any enthusiastic gardener, and provides one outlet for household organic waste disposal.
Disadvantages of the traditional compost heap are, however, well known. They include, among other items, the odor that they exude, the attraction to them of rodents and other pests, and the slow rate of action which they exhibit in reducing organic waste to compost. They operate in a generally uncontrolled environment, open to the elements, so that their operating conditions cannot be optimized to produce best quality compost in the shortest time.
Consequently, various forms of composting apparatus have been proposed and developed, to provide a more controlled and optimized composting environment, and to reduce the problem of odor and pests. One of the more successful of such apparatus is the one sold under the trade name "Green Cone", by Rubbermaid Inc, and described in U.S. Pat. No. 4,984,561, issued Jan. 15, 1991. This comprises a single, generally conical enclosure adapted to be placed in a shallow hole in the earth. The bottom portion of it, which is received in the earth, comprises a wire basket so that contact is made between the contents of the enclosure and the soil containing the necessary microbes required to initiate and continue the composting degradation. The upper, conical portion has a top access lid. When the lid is closed, the apparatus provides a substantially closed environment, to keep in the objectionable odors and to keep out the pests such as rodents, while the composting process proceeds. The temperature rises in the enclosure as the composting process takes place, thereby increasing the rate at which the composting takes place and increasing the rate of throughput of organic waste material.
All types of organic waste are not suitable for mixing together to form a common compostible mixture. Household organic wastes can be divided into two basic types, garden wastes and kitchen food wastes, to which different degradation criteria apply. If, for example, garden wastes and kitchen food wastes are mixed together in a single apparatus such as the aforementioned Green Cone, an unsatisfactory mixture occurs, components of which degrade at widely differing rates. Any attempts to remove from the apparatus compost for application to the growing area of a garden, at any given time, will result in the withdrawal of a mixture of fully degraded, partially degraded and substantially undegraded material, of little use for its intended purpose. The householder needs a plurality of such units, each devoted to the degradation of a single type of organic waste material.
It is an object of the present invention to provide a novel composting apparatus which overcomes or at least reduces one or more of the above-mentioned disadvantages.