Principles for the adjustment of the primary, secondary air are as follows:
The adjusting principle for the primary air and the secondary air is as follows:
--- The primary air is adopted for adjusting the bed material fluidization, bed temperature and bed pressure.
--- The secondary air should control the total air flow. Under the premise that the primary air satisfies the requirements of fluidization, bed temperature and layer pressure difference, if the total air flow is not enough, the secondary air damper can be opened gradually. The secondary air flow would be increased gradually as the load increases.
--- When the part of bed material is determined to be not appropriately fluidized, the primary air flow and the slag-discharging amount should be increased temporarily.
--- On height direction, the secondary air duct of boiler is divided into the upper one, the middle one and the lower one. Which should be largely opened and which should be slightly opened, the best working condition would be get according to the layer conditions after several tests during operation. Suggest: Burning bituminous coal,  below secondary air 100% fully open, up secondary air only 50% even 30%. The gasification of coal particle size is fine case or burn anthracite, lean coal, below secondary air on 100% of fully open, up secondary air only 50% even 30%.
--- The fluidization condition, the combustion condition and the back-feeding condition in the bed should be noted. If problem occurs, resolve it immediately. If the bed temperature rise or lower down, the rate between the primary air flow and the secondary air flow and the feeding amount should be adjusted.