Study on pressure balance in a single-loop solid circulation fluidized-bed system

Key words:  fluidized bed  dipleg  pressure balance  voidage  circulation loop

Abstract:

The relation of pressure balance must be kept properly in a circulation loop for keeping a fluidized-bed unit in working order. The pressure balance of a single-loop solid circulation system was experimentally studied in；a gas-solid fluidized-bed test facility with the diameter of 800 mm and the height of 12 000 mm by multi-point pressure detector. It is shown that the pressure balance is in close relation with the fluidized bed operation status and solid circulation rate. The measured pressure curve of the whole loop takes the shape of “8”. In the upper dilute region of the fluidized bed, its pressure is higher than that of the dipleg, while in the lower dilute region of the fluidized bed, its pressure is lower than that of the dipleg. With the increase of fluidization velocity, the solid circulation rate increases. The distributions of voidage in fluidized bed and dipl^ are both trending upwards on the top and downwards at the bottom. The distribution of pressure in a single loop depends on the properties of fluidized bed and cyclone.