Aerobic composting of household rubbish, sewage sludge, etc. - in which stack is force ventilated in both directions intermittently

摘要

Raw material for composting, such as disintegrated household rubbish and/or sedimented sludge and/or other material, to be composted by artificial aeration, has air circulated through it continuously in different directions; neighbouring ventilation channels being arranged so that of each pair, air is sucked through one whilst being blown through the other. The flow in each channel may be arranged as such and blow alternately; the single fan for each group of ventilation pipes having its direction of motion reversed intermittently. The air sucked in through the heap is vented by way of a deodorising filter and a gas analyser together with an automatic time switch is used to determine and actuate the frequency of flow changeover. Prevents the setting up in the heap of zones of anaerobic decomposition. After eight weeks the compost is ammonia and sulphide free.