A steam air heater transfers latent heat from condensing steam to air through a finned tube bundle. It is widely used in chemical, pharmaceutical, food, textile and drying applications because the coil is compact and responds quickly.

Selection points

• Define the air flow, inlet and outlet temperature and allowable air-side pressure drop
• Check the steam pressure and temperature against the tube and header design
• Select the fin type and tube material for the duty and atmosphere
• Set drain points so condensate cannot collect and cause water hammer

High-pressure duty

Copper tube has a lower pressure rating than steel. High-pressure steam heaters require thicker-wall tubes and a suitable expansion or brazing process. The pressure and temperature must be checked before the construction is fixed.

Part-load behaviour

A steam coil should be checked at part load as well as design load. If the steam flow falls too far, the coil can lose temperature uniformity or trap condensate. The circuit arrangement and control valve should be considered together.

Mazelu supplies steam air heaters for drying lines, washing equipment, HVAC and process air. Send the steam data and air duty for selection.