The Operating Principle Of The Air Preheater Axial Seal

An air preheater axial seal refers to a mechanism-typically involving sealing materials or similar measures-designed to maintain an airtight state in the axial direction, thereby preventing air leakage and mitigating airflow interference. Within an air preheater, axial seals are typically situated at the bearing locations or impeller positions; they are critical to enhancing both the performance and reliability of the engine.

Specifically, the operating principles of an axial seal are as follows:

Prevention of Air Leakage: Air leakage leads to a degradation in engine performance. Such leakage can be categorized into two types: static leakage and dynamic leakage. Static leakage refers to the air escaping through the clearance between the casing and the impeller, whereas dynamic leakage refers to the air escaping as a result of the impeller's rotation. By employing axial sealing measures, the clearance between the casing and the impeller can be effectively controlled, thereby minimizing air leakage.

Reduction of Airflow Interference: During engine operation, the clearance between the impeller and the casing inevitably gives rise to airflow interference. In this scenario, the leaking airflow disrupts the normal operation of the downstream impeller, thereby compromising the engine's overall performance. The primary function of an axial seal is to mitigate this airflow interference, thereby contributing to improvements in both the efficiency and reliability of the engine.