1. According to the characteristics of sewage quality, such as pH, solid material size, etc. To determine the specific form and material of the grid. The materials are carbon steel and stainless steel.
2. Large sewage treatment plants are generally equipped with two gratings and one screen. The spacing between gratings shall be determined according to the type, flow, type and size of representative debris in sewage to meet the requirements of pump structure and subsequent water treatment structure and equipment. Coarse grid (50~100 mm) or medium grid (20~4 mm) is used for roads, medium grid or fine grid (4~10 mm) is used for secondary roads, and screen (<4 mm) is used for tertiary roads.
3. There are five commonly used grid bar sectional shapes: square with side length of 20mm, round with diameter of 20mm, and 10mm × 50mm rectangle, 10mm with half round head on one side × 50mm rectangle, 1mm with half round head on both sides × 50mm rectangle. The circular grid has good hydraulic conditions, small flow resistance, but poor rigidity and is easy to be deformed by external forces. Therefore, when there is no special need, the rectangular section is adopted.
4. The grating is usually installed at the head of the treatment process or the water inlet of the pump station, belonging to the throat. To ensure safety, backup devices or other means shall be provided to ensure that the grid is maintained without water interruption.
5. In order to protect the power equipment, the mechanical grille is generally installed in a well ventilated grille room. Large and medium-sized grilles should be equipped with lifting equipment to facilitate equipment maintenance and daily removal of grille slag.
Selection of Grille Cleaner
Practice has proved that the selection of the screen trash remover directly affects the operation of the whole water treatment. For example, there are a lot of sundries in the sewage, such as nylon strips, pieces of plastic products, leaves, etc., It flows into the water tank, causing frequent blockage of the pump impeller.
