Rotating Bar Screens are an essential part of most sewage treatment projects. They are mainly made up of a set of parallel metal grids, which are placed obliquely on the inlet channel or the inlet of the pumping station sump. It is used to intercept large-scale pollutants in the sewage or floating channels in the sewage, and prevent the plugging of water pumps or pipelines.
In the operation and maintenance of all water treatment equipment, Rotating Bar Screen is one of the simplest equipments. If according to the removal method according to the dirt, the Rotating Bar Screen can be divided into two types of manual removal grille and mechanical removal grille.
The former type of Rotating Bar Screen is mainly to manually remove the dirt trapped on the grille and prevent the gap between the grids from jamming. In small and medium-sized sewage treatment stations, manual cleaning grids will be installed because of the small amount of pollutants that need to be retained. This type of grille is made of straight steel bars and is placed at an angle of 50~60° so that the effective grid area can be increased by 40% to 80%, and it is easy to clean and reduce head loss. The latter type of rotary mechanical grille is equipped with a mechanical removal grille in a relatively large-scale sewage treatment plant, and is generally set at 60 to 70° with the water surface and sometimes at an inclination angle of 90°.
Rotating Bar Screen transmission system there are several options, such as power transmission, hydraulic transmission and pneumatic transmission, but in the practical application of the project, the use of electric power transmission rotary mechanical grille more.
In addition, according to the same size of the grid bars, the rotary mechanical grid is generally divided into two basic types: coarse grid and fine grid.
Wherein the coarse grid is generally set in the sump of the pump station, and the fine grid is set in front of the grit chamber. According to the water treatment process, the grid general technology is set according to the principle of first coarse and fine detail. The grid spacing is determined based on the original water quality.