In general the packed tower gas scrubber is designed to remove noxious gases and corrosive fumes from ventilation or process streams. Although able to handle small quantities of dust within the stream, the possibility of blockage is a disadvantage of this type of unit. Under these conditions the impingement plate scrubber is recommended. The facility for recovering valuable process chemicals is a particular attraction of the packed tower.
In order to efficiently absorb contaminants such as HCL, SO2 and NH3, a large surface area of contact is required to achieve interaction between the liquid and gaseous phases. It is the nature of the contaminant, the concentration at the inlet and the desired efficiency which determine the type, size and quantity of packing.
Contaminated air or gas enters the scrubber inlet where it is contacted with scrubbing liquor draining from the packed bed. The flow of gas then rises, counter-current to the flow of the scrubbing liquor, through the packed section where neutralisation or removal of the contaminants takes place. The design of the packing promotes mass transfer with its multiple gas/liquid contact points, providing a large surface area, active surface renewal of the liquid phase and turbulent air flow characteristics. Before discharge to atmosphere the treated air passes through a droplet eliminator section at the top of the column.
Careful attention is paid to the design of the liquor distribution system, choice of packing, gas velocities and liquor flow rates in order to achieve optimum performance.
The main advantages of plastics are their resistance to corrosion and chemical attack along with their favourable price comparison to stainless steel or coated mild steel. Over forty years experience in the engineering and fabrication of plastics enables APMG to specify with confidence the right material for each particular application.
Materials of construction include:
Unplasticised Polyvinyl Chloride (uPVC) - Polypropylene - PVDF - ECTFE - CPVC - GRP reinforcement as required