Our NFK range of heat exchangers or surface coolers is designed to cool hot and dusty exhaust gases (approx. 550 °C) from melting furnaces, as e. g. cupolas, rotary furnaces, induction furnaces, and, as a result, allows the use of more economical filter media. The gases are cooled by ambient air supplied by fans fed through the horizontally installed cooling pockets. In addition to that, coarse dust particles are separated by means of deflection and, in special cases, the cooling surfaces are automatically cleaned.

Functional description

The hot gases are fed into the cooler from above. On the outer surfaces of the built-in sheet steel horizontal bags the heat is transmitted to the cool air, which is transmitted by axial flow fans through the cooling elements, as required.

In addition to its function to lower the temperature, the surface cooler also serves as preliminary separator of coarse dust particles from hot waste gases. The separated dust is emitted from the dust collection hopper by a screw conveyor and double pendulum flap.

If necessary, the cooler is fitted with a fully automatic cooling surface cleaning system which continously removes any possible dust deposits.


  • The cooler housing is constructed of reinforced welded steel sheets. The cooling fans are fixed to swinging doors allowing an easy inspection of the cooling elements.
  • The cooling unit consists of individual cooling elements made of steel sheets. The cooler elements, sealed with locking fasteners, are easy to maintain and can be removed from the front.
  • The fully automatic cleaning device, which has to be provided, if necessary, consists of a series of steel chains which are fixed to a swinging arm. The motion of these chains releases any dust particles from the outer surface of the cooling elements.