GB2275594A

GB2275594A - Compost sterilizer

Info

Publication number: GB2275594A
Application number: GB9304278A
Authority: GB
Inventors: John Phillips
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-03-03
Filing date: 1993-03-03
Publication date: 1994-09-07
Anticipated expiration: 2013-03-03
Also published as: GB2275594B; GB9304278D0

Abstract

A compost sterilizer in which, through the electrical conductivity and resistance of the wet compost, the compost temperature is raised to a maximum of 100 DEG celsius thus destroying harmful organisms. Electric current passes through the compost between electrodes 13 which are contained within box 10 and lid 14 as shown in Figure 1. The electric current passes through an optional ammeter 17 to a socket on the underside of the lid (19, Figure 2.) The socket engages with an upwards facing plug 11 mounted on the box. Conductors 12 are taken from this plug to the electrodes. Box 10 and lid 14 are made from rigid insulating material. <IMAGE>

Description

DESCRIPTION COMPOST STERILIZER This invention relates to a compost sterilizer.

Horticulturalists and gardeners need sterilized composts for seed sowing, potting on seedlings and transplanting into pots or larger containers. A sterilizer should not change significantly the essential qualities of the compost through excessive heat but harmful organisms, both animal and vegetable, must be destroyed.

This invention enables the horticulturalist and gardener to achieve the above aims using his or her own choice of compost mix.

The present invention utilizes the electrical conductivity and resistance of the wet compost itself to convert electrical energy into heat. It needs neither integral heating element nor external source of heat input.

The compost sterilizer will raise the temperature of composts to a maximum of 100" celsius thus destroying harmful organisms and rendering the compost suitable for horticultural use as a growing medium.

The compost sterilizer is illustrated by the following drawings: Figure 1 gives an isometric view with its lid raised and the optional ammeter mounted on the lid.

Figure 2 details the electrical socket on the underside of the lid.

The box 10 is made rigidly from an insulating material to withstand an operating temperature not exceeding 100" celsius. An upward facing two-pin electric plug 11 is mounted on one edge. From the electric plug conductors 12 run to two stainless steel sheet electrodes 13. The electrodes are fixed parallel to one another at either end of the inside of the box.

For a compost sterilizer powered from a 13 amp supply the area of each electrode is approximately 525 sq. cm.

The area for larger versions will be dependent upon the available power supply. The top edge of the box has grooves 20 corresponding with those on the inside of the box lid 21 to permit the free escape of steam.

The box lid 14 is also made from a rigid insulating material to withstand an operating temperature not exceeding 100" celsius. It has a deep flange 15 to fit snugly over the box sides with grooves 21 on the inside faces of the flange to permit the free escape of steam. Handles 16 are incorporated for ease of lid removal.

On top of the box lid is mounted an optional ammeter 17 and power cable entry point 22. The ammeter must be insulated and may be of a plug-in type in which case an electrical bridge 18 is necessary to complete the circuit when the ammeter is not used. On the underside of the box lid power is wired to a socket 19 mounted to correspond with the upward facing two-pin plug 11 on the box so that when the lid is placed on the box electrical continuity to the electrodes is achieved. Conversely when the lid is removed the electrodes are isolated electrically.

Sieved compost of chosen proportions (but no fertilizer) is mixed and placed in the box to within about 30mm of the top. For a sterilizer working from a 13 amp supply approximately 1.75 litres of water are poured evenly over the compost. The box is then topped up with more compost. The lid is placed on the box and the power supply connected.

The electric current input passing through the compost will rise and the compost temperature will rise to a level not exceeding 100" celsius. On achieving this temperature the current input will drop rapidly to zero and the compost then can be tipped out with care whilst still hot. It should be allowed to cool to ambient temperature before use when it will be friable and have a good moisture content for either seed sowing, potting-on seedlings or transplanting.

Claims

1. A compost sterilizer utilizing the electrical conductivity and resistance of the wet compost itself to convert electrical energy into heat, needing no integral heating element or external source of heat input.

2. A compost sterilizer as claimed in claim 1 capable of raising the temperature of composts to a maximum of 100" celsius thus destroying harmful organisms and rendering the compost suitable for horticultural use as a growing medium.

3. A compost sterilizer producing composts which, after cooling to ambient temperature, are friable and have a good moisture content for either seed sowing, potting-on seedlings or transplanting.

4. A compost sterilizer substantially as described herein and with reference to Figures 1 and 2.