Filtration is the most important treatment process in water purification to ensure water quality and quantity. The V-shaped filter has been widely used in water production processes due to its advantages of long filtration cycle, high fouling capacity of the filter layer, good effluent quality, good backwashing effect, and low backwashing water volume. The V-shaped filter adopts a flushing method that combines air-water backwashing and horizontal surface sweeping. The uniformity of water and air distribution is the main factor determining the backwashing effect, and the key to the uniformity of the water and air distribution system depends on whether the top surface of the filter head and filter cap is level and consistent. Ultimately attributed to the flatness of the filter plate in the filter tank.
The filter plate is a key device in the filtration process of water plants. It is the support plate for installing the filter head and plays a dual role in carrying the filter material layer and bearing the backwash water and air pressure in the filter tank. The quality of the filter plate directly affects the filtered water quality, water quantity, and long-term operating efficiency of the water plant.
At present, there are two main methods for the construction of filter heads and filter plates in China:
1、 Install the filter head on the precast concrete block filter plate, so it is required that the filter plate itself is flat, and the horizontal error of the entire filter plate should not exceed ± 3mm, in order to control the horizontal accuracy requirements of the top surface of the filter head and filter cap;
2、 A plastic template is used, and a concrete filter plate is poured as a whole on it, equipped with a long handle filter head that can be adjusted to a certain height to control the level of the top surface of the filter handle. The former is the traditional process adopted by many water plants at present; The latter is a new technology for water and gas distribution systems, which has been widely applied in more and more water and sewage treatment processes with the continuous promotion in recent years
The seamless integral casting filter plate is designed to address the drawbacks of traditional filter plates. It is poured as a whole without any joints, fundamentally eliminating the drawbacks of air leakage, sand leakage, and flipping caused by the cracking and peeling of the sealing adhesive of traditional filter plates. It has the following advantages:
(1) The arrangement of filter plate reinforcement is faster;
(2) The concrete structure is more complete and the structural stress is more reasonable;
(3) More uniform gas and water distribution;
(4) The precision requirements for civil construction are relatively low, and because it is poured on site, unnecessary losses caused by transportation, handling, and installation processes are avoided, thereby reducing project costs relatively.
The adjustable long handle filter head can adjust the horizontal accuracy of the filter head by adjusting the height of the filter rod up and down, so that all the inlet holes of the filter heads in the pool are at the same elevation. However, the horizontal accuracy of the traditional process filter head can only be achieved by adjusting the filter plate alone. By comparison, the adjustable long handled filter head is more uniform and ideal in terms of air and water distribution.