| 摘要 |
<p>1515623 Gassing of liquids GRIESHEIM GmbH 10 Aug 1976 [13 Sept 1975] 33247/76 Heading B1C In a tank 2 provided with a submerged pump 4 for introducing and recycling gas into and through a liquid, e.g. O 2 into an activated sludge, effluent sludge or river water, a gas tight cover 3 automatically adjusts to the volume of gas above the liquid and regulating means control the inlet and outlet of the gas in dependence upon the composition and/or physical state of the gas constituting said volume of gas. The cover may be an inflatable film 3 the height of which is transmitted to a scale 11 by a weighted line 8. When the cover is at its maximum height a weight actuates a switch 12 on the scale to close a valve 17 in the oxygen supply such that the pump only operates with recycled gas which causes the volume of gas above the liquid to decrease and hence the cover to sink. When the cover reaches a position in which the oxygen content of the gas mixture is 30-50% the weight actuates a further switch which opens an exhaust valve 19 through which the gas mixture escapes. The cover sinks to its lowest point at which the weight contacts a further switch 14 which closes the valve 19 and opens the valve 17 to allow oxygen to be reintroduced. The film height may be sensed by photocells. A bell shaped body which dips into the liquid may be used instead of the film.</p> |
