A rotary air preheater is a rotating mechanism. During operation, the preheater rotor rotates slowly, and there is a certain gap between the stator and rotor.  Due to the pressure difference between the air (positive pressure) flowing through the preheater and the flue gas (negative pressure), air will leak into the flue gas flow through these gaps, causing a significant amount of air leakage.

Hazards of air leakage in air preheaters:

An increase in air leakage will increase the power consumption of the forced draft and induced draft fans, increase the heat loss of smoke exhaust, and reduce the efficiency of the boiler. If the air leakage is too large, it can also cause insufficient air flow in the furnace, affecting the boiler output, and seriously causing boiler slagging.

The key issue in controlling the sealing gap of air preheaters is the measurement of preheater deformation. The difficulty lies in the fact that the deformed preheater rotor is in motion, and the temperature inside the air preheater is close to 400 ℃, while there is also a large amount of coal ash and corrosive gases inside. It is very difficult to detect the displacement of moving objects in such harsh environments. The gap measurement sensor GJCT-15-E is used in conjunction with the gap transmitter GJCF-15, specifically designed for this working environment to effectively measure the sealing gap of the air preheater and reduce air leakage.

Using the gap sensor GJCT-15-E to monitor and adjust the gap of the air preheater can significantly improve and strengthen the air entering the furnace after combustion through the waste heat exchanger, accelerate the drying, ignition, and combustion process of fuel, ensure stable combustion in the boiler, and improve combustion efficiency.