The HET heater is an indirect fired unit designed for most applications where there is a requirement to heat ambient process air to temperatures of up to 300°C in one lift. The unit consists of a stainless steel concentric tube type heat exchanger mounted in a mild steel chamber.
The outer casing of the unit is generally manufactured from carbon steel; it is double skinned and insulated with mineral wool. The unit can be constructed totally in stainless steel.
The inner assembly consists of a stainless steel combustion chamber and concentric cylinder heat exchanger; these are independently mounted within the casing to allow for differential expansion. The chamber is fitted with end inspection covers to facilitate cleaning.
Duties
Heater capacities of thermal outputs from 60kW to 1200kw are available; special units to meet the requirements of a particular application can be supplied.
Gas Supply Pressure
Typically, 20mbar. Higher inlet gas pressure can be accommodated.
Fuels
Burners can be fitted for operation with natural gas, LPG, light fuel oils.
Direction of Airflow
Standard HET heaters are arranged to fire horizontal in the direction of air flow from left to right (SF). Heater units can be supplied for firing into duct systems with vertical upwards or downwards air flow. Air flow should be uniform across the air duct, both upstream and downstream of the heater.