Drying aq. sludge to mfr. fertiliser, solid fuel, pigments, etc. - by injecting hot waste gas while agitating sludge

摘要

Individual particles in the sludge are subjected to intense agitation to obtain a powerful disintegrating action. Simultaneously with or immediately following the agitation, a dry gas is blown through the sludge and exhausted with a very high moisture content drawn from the sludge. The dry gas is pref. a high temp., industrial exhaust gas or hot air used as a heat transfer medium for industrial waste heat. Used for drying sludge passes with an initial dry solids content of 15-18%, to produce raw materials for solid fuels, pigments, fertilisers, etc. Simple inexpensive recovery of valuable residues using waste heat exhausted from industrial processes is obtd. The exhaust gases are purified before release to atmos.