Sludge Dryer

Description:

This sludge dryer uses flue exhaust to dry sludge form pulp and paper industry and then obtains sludge particles with dryness ranging from 65% to 75%.
This technology of using waste flue exhaust heat to dry sludge solves the original sludge drying problem of being unable to form into particles because the sludge is at a low temperature and wet. The dried sludge still has the same calorific value as before.

1.Feeding area:

to ensure sludge enter cylinder smoothly, this area is equipped with a spiral material guide plate to push material move into cylinder fast and deeply.

2.Pre-heating area:

this area is designed with countercurrent drying mode, and the exhaust end is also used as the material feeding end. When the flue exhaust comes to this area, its relative humidity is very big because of the full heat exchange before, so basically it does not absorb more moisture. But still, the gas has a higher temperature to pre-heat wet sludge as the preparation of further drying.

3.Pre-drying area:

sludge in this area have been basically dewatered and become relatively thicker, so the sludge are easy to stick onto the cylinder surface and shovelling plates. Therefore, the shovelling plates for this pre-drying area are designed with a special anti-bonding device, so that some wet sludge can adhere to this device. In that way, the specific surface area of sludge is enlarged, thereby improving heat exchange effects.

4.Granulating area:

in this area, sludge contain lower moisture, and the temperature and plasticity of sludge are good for granulation. so sludge can be made into granules quickly in this granulating area.

5.Constant-speed heat exchange area:

in this area, granulated sludge have flowability, and its moisture is in stable evaporation status. But the strength of granulated sludge is not strong enough, so to reduce breakage rate, their lifted height has to be under control.

6.Rapid evaporation area:

sludge in this area have good flowability and loose structure, which is good for heat exchange and moisture diffusion. Besides, this area has higher air temperature and lower moisture content. So double-bending shovelling plates are utilized to increase the contact ratio of sludge and hot air so as to enhance drying effects.

Working Principle Analysis of Sludge Dryer:

Considering the high moisture of sludge, this sludge dryer is designed with countercurrent drying mode. According to our almost 30 years experience, countercurrent drying mode is the most effective drying mode.