An SB canister pump from Bedford Pumps.
An SB canister pump from Bedford Pumps.

Bedford Pumps Ltd is supplying 16 dedicated WRAS/DWI approved vertically mounted submersible canister pumpsets, to provide a permanent water recirculation system for the slow sand filters beds at Thames Water’s Hampton and Kempton Water Treatment Works in the UK.

The pump company secured the two contracts with Thames Water by providing technical support and guidance on the design of the pump inlet chambers, which enabled suitable inlet flow conditions for stable pump operation to be achieved. Bedford Pumps says that a canister that it specially designed, plus a unique benching arrangement from hydraulic model testing consultants Hydrotec Ltd, were key to the success of this project.

Hampton and Kempton Water Treatment Works are key Thames Water sites for the supply of potable water to London. Both sites were without a permanent recirculation system for bed conditioning of their slow sand filters; the beds are currently drained using mobile diesel pumps and flexible hoses.

According to Bedford Pumps, the installation of a permanent recirculation system provided significant technical challenges for acceptable pump operation, particularly in achieving suitable pump inlet conditions due to the limited space available for the pump installation and the flow rates required.