Developments in the use of packaged high-recirculation airlift reactors

摘要

High Recirculation Airlift Reactors (HRAR) have been in use for the treatment of industrial wastes for a number of years. Developed in the 1970's by ICI and marketed under the name of 'Deep Shaft' the process has been extensively used in the Far East where land prices are at a premium and novel technologies are readily accepted. However recent research has further developed the mathematical modelling of the recirculation within the shaft which has allowed the design of a packaged HRAR system that fits into an area no larger than an articulated lorry. In fact the whole plant can be transported to site in a single ISO container. Designed to treat an effluent with a population equivalent of 1500 persons, the plant utilises a simple U tube or small concentric shaft of less than 1 m diameter as the reactor vessel. Final solids separation is achieved using natural flotation resulting from the super saturated nature of the effluent rising up the shaft. This paper describes the development of this system and provides some information on the performance of plants in use in Far East. Applications will also be discussed which outline the versatility of the system in treating a wide range of industrial effluents.