Air Strippers Air strippers are a cost effective method of volatilising volatile organic compounds from the liquid phase into the vapour phase. In many cases, such as for benzene or some chlorinated hydrocarbons such as 1,1,1-TCA, stripping efficiencies in excess of 99% can be achieved.
We design, build and supply air strippers for sale or rental for periods of as little as 1 month and up to 3 years or more. Flow capacities range from 5m3/hr to 200 m3/hr. Rental systems can typically be supplied "Off the shelf" or custom designed for a variety of applications in steel, stainless steel, PE or PP.
Systems can be supplied "stand alone" but are typically fully equipped with discharge pumps, level control systems and blowers and, frequently, mounted aspart of a complete water treatment system within an insulated & heated shipping container.
The systems shown above are all examples of integrated remediation systems comprising vacuum or pumping systems and associated aqueous and vapour phase treatment. The off-gas from an air stripper can be treated with vapour phase granular activated carbon (GAC) or with a catalytic oxidiser (see separate brochure sheet). Although the use of GAC for treatment of the off-gas might seem strange (why not use aqueous phase GAC inseatd?) vapour phase GAC is considerably more efficent than aqueous phase GAC. Also, some contaminants such as vinyl chloride cannot be adsorbed readily by aqueous phase GAC but can be air stripped and then adsorbed to vapour phase GAC.
When using GAC to treat the off-gas from an air stripper it is important to reduce the realtive humidity of the air such as by using a process gas heater.
Vacuum StrippersVacuum strippers are designed to facilitate the air stripping of less volatile contaminants from the liquid phase. Mass transfer of volatile compounds from the liquid to the vapour phase is significantly increased under conditions of lower absolute pressures. An applied vacuum to the air stripper column therefore enhances the strippability of compounds which are not readily stripped under normal conditions. Advantages include the requirement for only 1/5th of the air flow required for a normal stripper and the high concentration of the discharge vapours. Vacuum stripper work well with catalytic converters. Vacuum stripping is especially suitable for vinyl chloride contamination. |
