| 摘要 |
1,127,267. Drying sludge. W. LUDIN. 7 July, 1967 [12 July, 1966], No. 31498/67. Heading F4G. A process for drying sludge comprises drying in a thermal drying plant producing a watervapour-containing waste gas, wherein heat contained in the waste gas of the plant is used partially to dewater the sludge in a partial-pressure evaporator to which the sludge is fed prior to introduction into the drying plant. The waste gas from a drying plant substantially as described in Specification 1,097,846, viz a rotary drum drier 2 heated by a furnace 1 and cyclone separator 6, is fed to an air preheater 10 and thence both to a partial-pressure evaporator 12 containing sludge 12a and sludge preheater 11. The sludge is recirculated through lines 13, 14 from the heater to the evaporator and vice versa with fresh sludge being introduced into the line 14 and partially de-watered sludge is withdrawn from the evaporator through a line 17 to a mixer 4 for mixture with sawdust or the like absorbent carrier material prior to entry into the drier 2. |
