Plate Type Air Preheater: Efficient Heat Recovery for Industrial Applications

How does plate type air preheater work

A plate type air preheater operates by transferring heat from exhaust gases to incoming combustion air through a series of metal plates. These plates are arranged in a staggered pattern to maximize surface area and heat exchange efficiency. As hot exhaust gases flow over one side of the plates, the cold air passes over the opposite side, absorbing the thermal energy. This process significantly improves boiler efficiency by preheating combustion air, reducing fuel consumption by up to 10–15%. The design minimizes pressure drop and avoids cross-contamination between air and gas streams. Plate-type preheaters are widely used in power plants, refineries, and chemical industries due to their compact design, durability, and ability to handle high temperatures (up to 400°C). Their modular construction allows for easy maintenance and scalability.

What is plate type air preheater made of

Plate type air preheaters are primarily constructed from corrosion-resistant materials like corten steel, stainless steel (grades 304 or 316), or enamel-coated carbon steel to withstand high temperatures and acidic flue gas conditions. The plates are typically 1.2–2mm thick, with corrugated or finned surfaces to enhance heat transfer. Sealing systems use high-temperature gaskets or welded joints to prevent leakage. Advanced models may incorporate ceramic or composite materials for extreme environments. The frame and casing are usually made of structural steel with thermal insulation to minimize heat loss. These materials are selected based on operating conditions (e.g., sulfur content in fuel) to ensure a lifespan of 15–20 years with proper maintenance.