Differential Pressure of dilute phase zone of the chamber is a parameter reflecting the concentration of solid materials. Usually the pressure difference measured between the upper interfaces of the chamber with the  exit of the chamber is used as the testing value of the dilute phase zone of the chamber of. The bigger differential pressure value of the dilute phase zone explains the  higher  concentration of the material in the chamber, and the bigger heat transfer coefficient of the chamber, then the higher the boiler load can be taken, therefore during boiler operation, the differential pressure of the dilute phase zone of the chamber can be adjusted according to the boiler load requirement. And the differential pressure of the dilute phase zone of the chamber can be controlled according to the circulating ash amount discharged by the ash pipe under the boiler separation device. During operation, the upper limit and lower limit of one chamber differential pressure shall be set according to the ash content and partial size of the fuel coal kinds as the benchmark of starting and terminating the discharging of circulating materials.

In addition, the differential pressure of the dilute phase zone of the chamber is also one parameter of monitoring whether the returns feeder is working normally or not. During boiler operation, if the material circulation stops, then the differential pressure of the chamber will suddenly go down, so special attention shall be paid in the operation.    (lsh)