| 摘要 |
<p>PURPOSE:To prevent exactly the mixing of combustible gas and oxygen in conduit by discontinuing the supply of oxygen when a waste-deficient space occurs in conduit in a waste water treatment in which oxygen is supplied into a conduit through which polluted water is introduced. CONSTITUTION:The pure oxygen 16 is supplied into the conduit 14 through which sludge is returned to the aeration tank 12 and the oxygen intrudes into the inside of the sludge flocs to activate bacteria present in sludge sufficiently. The conduit 14 is provided with the polluted water detector 18 which sends forth a detection signal when the pumping-up of return sludge from the sedimentation tank 10 is discontinued or a polluted water-deficient (in more than a fixed amount) space occurs in the conduit due to gas contained in sludge, by which the valve 20 is closed to stop the supply of oxygen to the conduit 14. Thus, even in case where combustible gas is filled up the space, the mixing of oxygen and the combustible gas can be prevented and therefore danger of explosion, etc., can be completely prevented.</p> |
