When using the self-cleaning heat exchanger technology chemicals are not required as online additives or needed for cleaning purposes. Therefore, there are no hazardous waste streams from cleaning which makes the heat exchanger more sustainable
All MSF plants for sea water desalination use a chemical additive to suppress fouling or scaling of sea water in the condenser section or the top brine heater. Already in the late 1970’s at the Island of Texel a MSF plant with a vertical orientation has been built and operated that applied a fluidized bed in the tubes of the condenser and final heater and could run without the need of chemicals to prevent scaling.
PTA coolers face a major issue of fouling. A major PTA producer has to clean the PTA coolers every 6 hours. Cleaning of these PTA coolers is done using chemical solutions i.e. caustic solution (5% w/w caustic @ 80°C). After cleaning they have to dispose the caustic solution which contains valuable terephthalic acid crystals. Replacing the existing PTA coolers with the self- cleaning coolers will enable the PTA producer to skip the caustic cleaning of the heat exchanger and thus there will be no disposal of the cleaning solution.
