Optimisation of Routine Cleaning & Disinfection Procedure using EPSCO's Microsolve method
Scottish Power's Rye House Power Station utilises both cooling towers and air cooled condensers to perform the cooling requirements of the station. The cooling tower has been in place for approximately 17 years and the majority of the circulating cooling water is demineralised water. Over the stations lifespan there have been a number of different methods used to clean and disinfect the tower and following a number of years of EPSCOs successful works at another Scottish Power Site (Blackburn Mill) we were approached to perform a routine cleaning and disinfection procedure.
The objective tasked to EPSCO was to perform a thorough cleaning and disinfection procedure to remove any deposits build up in the wetted and unwetted areas. This cleaning and disinfection procedure was to be supplemented with pre and post digital and endoscopic images to prove the effectiveness of the procedure.
EPSCO Systems & Process
EPSCO used its own patented Microsolve® system for the chemical cleaning and disinfection of the cooling tower. The system consists of a range of specifically designed chemical treatment agents along with a number of chemical pumping rigs to facilitate dilution and delivery of treatment agents to the areas of application.
Stage 1 – Initial Visit & Condition Survey:
Once approached by Rye House an operations team met with Adrian Bailey (CCGT Plant Chemist) on site to discuss the EPSCO method and how this would be applied on the cooling tower at Rye House. Along with the discussions on the Microsolve® system our personnel performed a survey of the cooling tower to determine the current condition and levels of deposits present within the tower. This survey allows us to select the suitable chemistry for the treatment of the tower and allows a full proposal to be prepared including a turnkey quotation along with site specific safety documents.
The survey showed that the packing was in a good condition with minimal deposits but the remainder of the tower was subject to a large build-up of both bacteriological slimes and algae in the upper sections and iron staining in the lower wetted areas.
Stage 2 – Cleaning and Disinfection of Cooling Tower:
Following the survey and the approval of our proposal we attended site to carry out the cleaning and disinfection work scope. The procedure was carried out over 2 days on site and treated all the wetted and unwetted areas. This was inclusive of sound attenuators, drift eliminators, upper dry/wet sections, packing, individual sumps and the common sump.
The iron deposits present in the lower wetted areas and bacteriological deposits in the upper areas have been present for many years and previous cleaning and disinfection procedures have only been successful in removing a portion of these deposits. By using the EPSCO Microsolve® method over 95% of these deposits were removed throughout the tower leaving only small areas of ingrained staining.
All wash water and spent chemicals were contained within the common sump, neutralised and discharged in accordance with the client’s consents.
A full and detailed report was produced following the procedure which was inclusive of a cleaning and disinfection certificate, observations report and supporting endoscopic and digital images from all of the cells treated for the client’s records. Some representative images are shown below
Sump Area - Pre Sump Area - Post
Upper Dry Area - Pre Upper Dry Area - Post
The project was completed on-time and on budget through a process of effective communication and teamwork between EPSCO project teams, on-site contacts and area authorities. All work was undertaken safely in-line with site procedures with ZERO ACCIDENTS or near-misses. It is intended that a regular cleaning period shall be determine through on-going intermediate cleanliness monitoring by site and conditions noted at future cleaning work.