| 摘要 |
<p><PICT:1042707/C1/1> The invention of the parent Specification is modified by mounting the heater circulator units round the outside of the digester instead of in the roof thereof. In Fig. 1, sludge from the bottom of tank 1 enters via tube 3, passes up tube 5 where it is heated by the fluid in jacket 6, and is returned to the tank by outlet 4. Raw sludge is fed in at 7, and gas under pressure, which may be derived from the top of the tank, at 8. Hot water, which may be about 150 DEG F. enters the jacket 6 at 6B and leaves at 6A. The sludge in the tank is preferably maintained at 85 DEG F. and the stream of gas escaping at 4 into the tank breaks up the scum. The heating jacket may be insulated with materials such as glass fibre.</p> |
