Date: 31/8/09
Flexseal couplings played a vital role in this refurbishment,
as after the removal of the lateral asbestos pipes, the project required connecting around 200 new lateral plastic pipes to existing pipe outlets.
The main objective of the project was the replacement of the packing; the 5m deep modular block system used to cool the water. The reasons for this are three-fold; to improve the thermal performance of the cooling towers, to remove the increasing levels of siltation and also to ensure the structural integrity of the system for the next 20 years. It also provided an ideal opportunity to remove the 350 tonnes of asbestos pipe which dates to the original build in the 1960s.
The black surface seen in the photos is the new
thin-film plastic packing system. The hot water flows into the cooling tower at a temperature of 27.3 degrees C, flows through
the new pipes and out of the sprinklers shown on the images. It is cooled to 17.8 degrees C whilst filtering through the blocks, before being fed into a canal system underneath, and pumped back into
the power generation system. The flow rate per tower is around 6.3 millions gallons per hour, at 0.44bar per pipe.
The contractors considered using fibreglass cement as an alternative to
couplings – a more time consuming and complex procedure. Also, the use of couplings didn't require a detailed risk assessment with full coshh data.
This case study will be updated as and when progress is made.