GAS CONDITIONING TOWER

Cooling of process gas through gas conditioning

Gas conditioning towers (GCT) are found above all in the cement industry, where they are used to directly cool hot process gas from the preheating tower to a filter temperature of at most 120° Celsius. The gas stream and therefore the dust are cooled to the desired temperature through the evaporation of extremely fine water droplets injected into the gas stream.

The main components of an GCT are:

- the gas entry cone with fittings for distributing
  the gas
- the cylindrical portion in which the exhaust gas 
  is cooled by the injection and evaporation of
  water
- the dust collection basin, where dust stripped 
                                                                               from the gas collects
- the sprayer system, mounted on the cylindrical portion and consisting of lances equipped
  with injection nozzles, a water supply system with centrifugal pumps and a motor control 
  valve, a temperature regulating system with sensors, a control unit and display
  instrumentation.

The nozzles can be executed as a two-component nozzle, in which the water is aerosolized using compressed air, or as a single-component version, in which the water is aerosolized using high pressure (~ 35 bar). The amount of aerosolized liquid is controlled using a spill-back system. To ensure the complete evaporation of the water within the calculated retention time of the water droplets, a uniform inflow to the spray lances is necessary along the entire length of the evaporation zone. Important for this process is flow control in the inlet and outlet segments of the GCT.

The required geometry was calculated before hand by Scheuch in cooperation with the Johannes Keppler University in Linz using a flow simulation program and then tested and optimized using a test 
                                                                      model.