Sealing Ways for Sludge Dryer System

The sealing form of the sludge dryer system are labyrinth seal and end face seal, labyrinth seal is widely used in sludge dryer system.

Sealing device in the dryer is an integral part, if excess cold air enter the intake air endn of the dryer, the hot gas temperature will reduce, which affects the thermal efficiency. If the outlet end leakage into the large amount of cold air, The exhaust gas temperature is likely to dew, which affects the normal work of dust removal equipment.At the same time downdraught phenomenon often appears in operation, if there is no overflow sealing device, a lot of dust will pollute workshop environment, thus sealing type drying machine is very important. 
Labyrinth seal is regularly applied in the dryer, one is axial seal and the other one is radial labyrinth seal. The stationary ring is fixed on the furnace wall or the discharge cover, and the movable ring is welded on the cylinder to avoid the phase conflict between each ring in the operation. A larger gap between the sealing rings should be kept, so the sealing effect is poor. The stationary ring can be axially moved to the radial labyrinth seal structure, and its fixed seat is fixed on the wall of the smoke chamber or the unloading hopper. The stationary ring is sheathed in the fixing seat, and the middle of the fixed seat is filled with asbestos rope. Because that the static ring can move axially, so the clearance of the sealing ring can be greatly reduced and the sealing effect is good. For movable ring axial movement radial labyrinth seal structure, The stationary ring is sheathed on the cylinder body and can be adapted to the movement of the cylinder. Because the sealing ring for welding parts are without processing, sealing effect is slightly worse, but the production is simple, material is saved, which makes it be a kind of comprehensive better structure. 
The end face seal is an axial end face seal structure with a sleeve asbestos rope. The stationary ring is fixed on the furnace wall, the gap between the movable sleeve and the static ring is filled with asbestos cord. One end of the asbestos cord is fixed and the other one is strained by heavy hammer tension. Because of the hammer, The sealing ring on the upper end face of the movable sleeve and the rotating sealing ring on the cylinder body are compressed, which plays the role of the axial end seal. This structure can adapt to the axial and radial swing of the cylinder, the sealing effect is good and widely used in the rotary kiln. But the end face sealing ring wear faster the structure in the dryer is less used.
The labyrinth type sealing structure has better effect on the sludge dryer system, and the material is saved at the same time.