Proceedings

Many of the water companies, including Thames Water, are moving towards THP digestion. Controlling the feed to THP and achieving consistency is very important to operations. Sludge too thin will result in the steam demand being very high – increasing Opex costs. Sludge too thick will result in rat-holing of the steam through the sludge, poor hydrolysis and experience shows leads to significant maintenance issues. Being able to control the dry solids of the feed to the THP consistently is critical to successful and cost effective operation.

This paper reports on how this can be consistent feed to THP can be achieved reliably, looking at the whole life cost benefits and the control philosophy necessary.

Keywords: pre-THP dewatering, process control, operational experience