Gas conditioning towers (GCT) are used in industrial applications to cool gases upstream of electrostatic precipitators / bag filters for effective temperature control, gas volume reduction and humidification by the evaporation of water. GEA provide the two available atomization technologies utilized in the evaporative cooling process are hydraulic atomization and twin-fluid atomization. Key parameter for GCT sizing is in addition to the amount of flue gas, inlet and outlet temperature mainly the attainable droplet size and the associated energy consumption.
Key features:
- Low maintenance and low maintenance costs
- Compact design
- Cleaning function available only after a specific deadtime
Working Principle
Working Principle of Gas Conditioning Towers
Hydraulic atomization with single fluid, spillback nozzles with larger droplet sizes provide less energy consumption but require a larger casing design and more purity on the cooling water. The amount of liquid injected is adjusted via a control valve in the spillback line, whereby part of the flow is taken from the inlet flow rate and returned to the buffer tank.
Twin fluid technology utilizes compressed air or steam to atomize the water into droplets via a spray injection nozzle/lance as well. The water and compressed air (the two fluids) combine inside the nozzle and exit into the flue gas stream. Smaller droplet sizes lead to smaller casing design and even wastewater can be used for Zero Liquid Discharge (ZLD) where recovered waste heat supports efficient evaporation of water for compliance with wastewater discharge limits.
The GCT casing structural design covers full under pressure of ID fan and is providing adequate gas distribution with deflection-, guide- and perforated sheets in the inlet area.
The transport of dust from the housing is taken into account for possible malfunctions with a reversible paddle screw and motor-driven double pendulum flaps on both sides.
