The second filter screen is a kind of equipment which can effectively purify the dirt in water, keep the condenser water chamber in a clean state, ensure the normal operation of rubber ball and improve the recovery rate of rubber ball. However, China's environmental problems are relatively serious, especially in rivers and lakes.

Therefore, the two common secondary filtration methods in the cooling water start-up circulation system: rubber joint fixed type and rotary negative pressure reflux type, all show their shortcomings. In recent years, the secondary filter screen has been continuously improved, some old product structures have been retained, the electric device has been added, and the enhanced sewage device has been added, which makes the structure and performance of the secondary filter screen more perfect. It is widely used in the cooling water open circulation system of 6MW to 300MW Thermal power units.

Submit.

The cleaning capacity of this kind of filter screen is stronger than that of fixed filter screen. However, in the flood season, when the cargo water pollution is serious, and the water contains plastic film. The cleaning effect is still not ideal for weeds and other sticky dirt. If the scraper in the sewage chamber is seriously worn, the cleaning effect is poor, and there are big defects in the structure

A pair of big and small gears of transmission mesh core work in water with high sand content all year round, which is easy to cause wear and corrosion. High pressure hose seriously affects the safe and economic operation of the unit.

The drive control system is relatively complex, which is generally composed of control solenoid valve, oil pump, oil tank, oil cylinder, oil motor, oil circuit control box, etc. in the process of use, oil leakage and control failure are most likely to occur.

Repair and overhaul work is heavy.