METHOD FOR REDUCING WEIGHT OF SLUDGE BY DIGESTION AND DEVICE THEREFOR

• Main Authors: MORI SHOICHI, KAZUMA KENJI, TSUCHIDA TOMOHIKO
• Format: Patent
• Language: English
• Published: 02.05.1995
• Edition: 6
• Subjects: CHEMISTRY; METALLURGY; TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE

PURPOSE:To reduce the weight of sludge by digestion in high efficiency by dissolving the digestion gas having the content accelerating the digestion of the sludge into a sludge-containing waste water at a pressurized state, then dispersedly injecting the bubbles of the digestion gas into the waste water at normal pressure level, sticking the sludge to the bubbles to floatedly separate and concentrating the sludge and recirculating it. CONSTITUTION:In the tank 1 which digests the sludge and reduce its weight, a floatedly separating tank 2 and a concentrated sludge tank 3 are formed by a partition wall 1a. In a gas-liq. mixing deice 4, the concentrated liq. from the concentrated sludge tank 3 and the digestion gas are mixed. Moreover, the waste liq. from the gas-liq. mixing device 4 is pressurized by using a pressure pump 5. In a gas-liq. contact mixing device 6, the digestion gas in the waste liq. from the pressure pump 5 is dispersed finely. Moreover, the pressure of the waste liq. from the gas-liq. contact mixing device 6 is reduced by using a reducing valve 7. In a bubble dispersedly injecting device 8, digestion gas bubbles are dispersedly injected into the waste liq. from the reducing valve 7, and the gas-liq. from the bubble dispersedly injecting device 8 is supplied to the bottom part of the floatedly separating tank 2. As a result, the weight of the sludge is reduced by digestion in high efficiency.