Because pathogens are not heat-resistant, pasteurization mainly uses this property to heat the liquid to a specific temperature and maintain it for a period of time, thereby killing the pathogen. The core equipment of the pasteurization system is a heat exchanger, which uses steam or electric heating as the heat source. The disinfection medium can be purified water, or the purified water in the storage tank can be heated by a jacket as a sterilizer. Usually, the water temperature is controlled. above 80°C. This disinfection method is more environmentally friendly, low cost, safe and effective, and has excellent verifiability and disinfection effect, so it is often used in the disinfection of purified water systems. So, where is pasteurization used in purified water systems?

1. Activated carbon filter. Due to the numerous pores of different sizes on the surface of activated carbon, the adsorption of a large amount of total organic carbon will lead to the growth of microorganisms. When the system runs for a long time, these microorganisms are likely to leak to the subsequent treatment units, affecting the subsequent water treatment effect and bringing a greater risk of microbial contamination. Therefore, activated carbon filters need to be set for high temperature sterilization. The activated carbon filter supports forward washing and backwashing. Here, pasteurization is used for periodic disinfection, which is a very effective disinfection method.
2. Reverse osmosis system. The optimal working temperature of the reverse osmosis membrane is 25℃, and the water yield is the best at this temperature. Usually, a heat exchanger is used to control the water entering the reverse osmosis, so that the temperature of the influent water is maintained at (25±2) °C. The heat exchanger can choose the electric heating heat exchanger and double tube sheet heat exchanger to prevent cross contamination, and the heat exchanger can also realize the pasteurization function of the RO/EDI system.

3. EDI system. Pasteurization can also be applied to the periodic sterilization of EDI.

4. Storage and distribution pipe network. Since the pump generates heat and needs to be cooled after disinfection, the storage and distribution system of purified water needs to be heated first and then cooled when it is periodically disinfected by pasteurization. All the purified water in storage tanks and pipelines are often heated to above 80°C, and circulated in the system for 1 to 2 hours to achieve pasteurization.
When designing a water system, if pasteurization is selected, the heat resistance of all materials that come into contact with hot water needs to be considered. For example, the purified water storage tank is made of stainless steel, and the softening resin is selected to be high temperature resistant.