Flat-tube heat exchanger

Flat-tube heat exchangers are – if necessary – installed upstream of flat-bag filters in order to reduce the temperature of the gases to be cleaned to a temperature admissible for the filter fabric or to adjust the optimum process temperature. During development of this heat exchanger special importance was attached to the objective to achieve a reliable continuous operation, combined with a constant cooling of gases, even in case of high particle loads in the gas and in case of a strongly adhesive character of these particles. Occasional manual cleaning proved to be unnecessary for maintaining the heat transfer.

If necessary we are taking additional measures to ensure a trouble-free continuous operation of the flat-tube heat exchanger and exceptionally long service lives of cooling tubes.

  • Utilisation of a mechanically working cooling area cleaning device in case of presence of particles with adhesive features.
  • Avoidance of temperatures below the dew point by using pre-heated cooling air (cooling air re-circulation)
  • Avoidance of temperatures below the acid dew point by means of injection of additive powders in the flue gas flow upstream heat exchanger

On request there are different possibilities of heat recovery available, e.g. in form of hot water generation.



View of chain curtain cleaning device in a heat exchanger hood

View of chain curtain cleaning device in a heat exchanger collection hopper

The cooling takes place through indirect heat exchange of the gas to be cooled and the aspirated ambient air of cooler. The gas to be cooled flows between the external surfaces of the horizontally located cooling tubes either from the top to the bottom or from the bottom to the top. A part of its heat is transferred to the cooling air flowing inside of cooling tubes. By means of re-circulation of a part of the cooling air and, if necessary, additional additive powder injection into the gas, it is, if essential, ensured that the water and/or acid dew point near the walls charged by the gas will not be undershot. Corrosion and caking are avoided. In case the particles tend to be adhesive, the heat exchanger will be provided with a cleaning device, running in automatic operation during charging of heat exchanger. Chains are slowly moving to and fro between the flat-tube rows. In doing so, the thickness of particle layer deposited on the flat-tubes will be limited.



Flat-tube heat exchanger without cooling air re-circulation (type F)

Flat-tube heat exchanger with cooling air re-circulation (type FR)