Cooling tower packing is a crucial part of a cooling tower, as it ensures the space between air and water is optimised to enable cooling.
It is important to ensure that the cooling tower pack is in a suitably clean state. Evidence of its cleanliness should be demonstrated and recorded as detailed in HSG 274 Part 1 Pages 32 and 37.
There is no real substitute for removing the cooling tower pack to enable cleaning and inspection. However, this is not always practical or even possible. In cases where the cooling tower pack cannot be removed for cleaning, a lightly fouled or scaled pack can be cleaned in situ using a suitable foam cleaning chemical system.
PackCleanse range
The PackCleanse cleaning system effectively cleans light to moderately fouled packs by combining the disinfecting power of chlorine dioxide with the cleaning power of a weakly acidic surfactant mixture. The system produces a high-cling foam which is applied to surfaces to be cleaned under low pressure.
Products in the range are:
- PackCleanse Foamgel - This product is central to the range. It is based on a phosphoric acid and a foaming agent tolerant to acid and chlorine dioxide.
- PackCleanse Foamgel Safe - A low acid version of PackCleanse Foamgel for use where corrosion may be an issue.
- PackCleanse CD - A stabilised chlorine dioxide solution. It is packed in 250 ml containers, sufficient to generate 500 ppm of chlorine dioxide in 10 litres of PackCleanse Foamgel.
- PackCleanse Defoamer - This product has been specifically designed to counter the foaming properties of the Foamgels without leaving residues.
- PackCleanse Neutraliser - This product neutralises both excess acidity and chlorine dioxide, allowing safe disposal of the spent cleaning solution from the tower.
Benefits of PackCleanse
The PackCleanse range offers a number of benefits:
- Eliminates the need for an air supply
- No need to remove cooling tower pack, saving time and reducing potential damage
- Good pack penetration
- Easily applied
- Decreases downtime
- Removes potential hazards from aerosols
- Cleaning effect can be monitored visually
How to use PackCleanse
The cleaning procedure based on the PackCleanse Foamgel is intended for the routine cleaning of slightly scaled systems and not the descaling of badly fouled towers. Do not use PackCleanse to clean evaporative condensers.
Select the PackCleanse Foamgel for slightly scaled systems and the PackCleanse Foamgel Safe for systems with no apparent scale, or where there are components vulnerable to acidic attack.
This method is intended to replace the pack removal step in a tower cleaning procedure where it is not practical to remove the tower packing. Removing the pack for cleaning is regarded as best practice by the HSE but alternative methods of cleaning the tower may be considered where there are practical difficulties in doing so. The efficacy of the alternative procedure must be verified.
It is essential to use an appropriate foam lance attachment for the jet washer in order to apply PackCleanse Foam in the correct manner. A foam lance will ensure the foam consistency is correct in order to adhere sufficiently to the internals of the pack and allow sufficient time to allow for any general organic debris, scale or biofilm to be effectively removed or dispersed.
HSG 274 requires the following steps:
- Pre-clean disinfection
- Pack removal and tower clean
- Post-clean disinfection
The basic steps for utilising a foam cleaning system are:
- Pre-clean disinfection
- Foam the pack
- Rinse the pack thoroughly using defoamer neutraliser
- Verify the efficacy of the clean, repeating the procedure as necessary
- Clean the tower
- Post-clean disinfection
The interior of the pack can be inspected using an endoscope in order to evaluate the thoroughness of the clean, particularly in areas of the pack which cannot be visually inspected. A guideline method statement for use of the PackCleanse range is available on request from our technical department. To access the statement or find out more about the range, get in touch.
