ACWA Services Ltd
11 products found
ACWA Services Ltd products
Air
Plate Scrubbers
Plate scrubbers are a highly efficient means of particulate removal, absorption of contaminants and gas cooling. In this type of scrubber (see above), the gas passes upwards through a number of small holes in one or more plates. Liquor enters on the top plate, flows across it and through a downcomer to the plate below. Intimate gas liquid contact is obtained as the gas bubbles through the liquid on the plate.
Venturi Scrubbers
Venturi scrubbers are an effective means of removing sub micron particulates. The contaminated gas is accelerated in the converging section before entering the throat (see left). Scrubbing liquor enters around the top of the converging section and completely flushes the wall. In addition, liquor enters through a spray to fill the throat with droplets.Packed Towers
This type of scrubber is designed for the absorption of gaseous contaminants and has been in use for over a hundred years. The dirty gas enters at the bottom of the tower and passes through the packing, counter current to the liquor, which is introduced at the top of the scrubber via a distributor. The packing is a randomly dumped media which has a high contact surface area for the efficient absorption of gases into liquids with a low gas pressure drop.Air Stripping
Dissolved gases such as hydrocarbons (VOC"s), carbon dioxide, ammonia and hydrogen sulphide can be removed from water by stripping (desorbing) by contacting the water with ambient air in a packed column. The water to be treated enters the top of a packed tower and is distributed over the top of a packed bed and flows down through the packing. Fans blow ambient air into the base of the tower and this flows up through the packing where it contacts the water stripping out the VOC contaminants. The air containing the stripped VOC"s passes through a demister to remove water droplets and is vented to atmosphere. The stripped water collects in the base of the stripping tower from where it is discharged.Dry Scrubbing
In "dry scrubbing" a solid sorbent is injected into the gas stream which reacts with the contaminant and is removed on a filter, together with any other particulates. This produces a dry powder for disposal. Alkalis such as lime or sodium bicarbonate are injected for the removal of acid gases such as sulphur dioxide and hydrogen chloride. Powdered active carbons can be injected to remove heavy metals and trace organic compounds such as dioxin.Thermal Oxidation
Thermal oxidation is the incineration of solvents, hydrocarbon vapours, fumes and odours. The temperature of the waste gases is heated to a temperature of 750 to 1100°C by a gas or oil fired burner which fires into a ceramic lined combustion chamber. This is fitted with internal baffling to provide the necessary mixing and residence time required for the oxidation of the contaminants. The hot gases from the combustion chamber can be used to preheat the incoming fume to reduce the consumption of the support fuel. Where appropriate, the further heat can be recovered in the form of hot air, heat transfer oil or steam.Water
Pressure Filters
The great majority of projects in which ACWA have been involved, include some form of particle filtration. The finest forms of particle filtration are membrane filters, which are covered elsewhere. Membranes are high cost equipment items and very susceptible to damage and generally must be protected by some form of more open filters such as cartridge filters, strainers, sand filters or the like.Granular Activated Carbon
GAC filtration is used in the water and manufacturing industries to ensure water supplies are free of organics taste, odour, colour and pesticides.