Sludge two-grade united energy-saving drying device and method

Abstract

The invention relates to a sludge two-grade united energy-saving drying device and a sludge two-grade united energy-saving drying method. The sludge two-grade united energy-saving drying device includes a steam generator, a heater, a direct stirring dryer, a blower, a cyclone dust collector, a filter, a steam compressor, a valve, a sludge pump, an indirect sludge dryer and a spiral feeder. The sludge pump, the direct stirring dryer, the spiral feeder, and the indirect sludge dryer are formed to be a material access; the steam generator, the heater, the direct stirring dryer, the blower, the cyclone dust collector, the filter, the steam compressor, and the valve are formed to be a first-grade drying gas flow access; the valve and the indirect sludge dryer are formed to be a secondary-grade drying gas flow access. The invention has the beneficial effects of crossing through a sludge viscous zone through a two-grade drying method, and solving the viscous problem caused by high water content of sludge in indirect drying; besides, residual steam is used as the hot source for the next-grade drying, the potential heat and a part of sensible heat of the excessive steam can be generated during the recycling and drying processes, and thus the gradient utilization of energy can be realized.

Description

technical field [0001] The invention belongs to the field of sludge drying, and in particular relates to a sludge two-stage combined energy-saving drying device and method. Background technique [0002] As my country pays more and more attention to environmental protection, sewage treatment plants are faced with how to deal with a large amount of sludge generated every day. However, the moisture content of the sludge generally treated by ordinary mechanical dehydration is still as high as 75%-85%, so further drying treatment is required. [0003] The current drying process mainly includes heat convection drying and heat conduction drying. Thermal convection drying has high energy efficiency and fast drying speed, but the cost of tail gas treatment is high, so this drying system is more suitable for the full drying process. Indirect heat conduction drying can recycle the drying medium, but it is easy to produce sticky walls in the stage of high moisture content of sludge, r...

AI Technical Summary

Problems solved by technology

[0008] In view of the problems existing in the above-mentioned prior art, the present invention provides a sludge two-stage combined energy-saving drying device and method. On the one hand, it can solve the problem of sticking to the wall during the drying process due to the high water content of the sludge when the sludge is indirectly dried. On the other hand, the excess superheated steam generated in the drying process is used as the heat source for the next stage of drying, and the latent heat of the excess steam generated in the drying is fully recovered and utilized, which improves the utilization rate of energy

Images