Experiment of defouling characteristics of backwash in pipes by thermal resistance method

Puts forward a scheme to remove fouling in pipes by free-spring and backwash. Performs experiments of fouling removal efficiency (FRE) of backwash in pipes with and without free-spring. The results show that water quality has a strong influence on the FRE of backwash when no free-spring is added in the pipe, and the FRE of city water is high. Adding free-spring in pipes will further increase the FRE of backwash in pipes because of its better fouling removing ability. The free-spring is simpler in structure and easier to be put into heat exchange pipes, and leads to a small additional hydraulic lose of the heat exchanger.