Moving Bed Operation:

A somewhat different type of column operation is that encountered in a moving bed or continuous counter-current system. Within such a system, the resin as well as the solution, is made to flow by the system. A classical unit consists of two stages in which the resin is contacted counter-currently with the exhausting stream and the regenerant stream. The chemistry of such an operation is similar to fixed bed operation.

The advantages of moving bed operation are those with continuous operation say a constant supply of a product of uniform quality and reduced cost of space, capital and labour. There are some design problems because of the movement of resin. Maintaining a counter- current flow of resin and solution depends upon the densities of two phases.