After the CDQ primary deduster puts into operation for years,it would occur the problems such as castable flake-off at the inlet expansion joint,frequent false alarm of level indicator,internal leakage of water-cooling jacket and slow discharge of dust,etc..Measures have been taken to improve the primary deduster,i.e.the inlet expansion joint is made of refractory bricks,electrostatic capacitance type level indicator is changed to resistor type,coke breeze is cooled by boiler blowdown through water-cooling jacket and coke dust discharge method is modified.After the improvement,the primary dedusting system can run in a stabler level and the CDQ unit can be in a more environmental-friendly operation.

"> CDQ, Expansion joint, Primary deduster, Level indicator, Water-cooling jacket tube