The volume of the sump of the sewage pumping station should be determined according to the changes in the flow of people entering, the model, number, working system of the selected sewage pump, the nature of the operation of the pumping station, and the starting time. Too large a sump volume will cause a large amount of siltation in the pool and increase the project cost; too small a volume can not meet the requirements of water halo adjustment. Therefore, the volume of the sump should be reasonably determined based on the above conditions.
The volume of the sump should meet the installation requirements of the hydraulic layout, the grille and the suction pipe of the sewage lift pump. On the basis of timely water pumping in the future and avoiding the frequent opening and closing of the pump, the pool volume should be minimized to reduce costs and reduce the amount of dirt. Siltation and corruption in the pond. The sump volume includes dead water volume and effective volume. Dead water volume refers to the volume below the lowest water level, and the effective volume refers to the volume between the highest water level and the lowest water level in the sump. According to the drainage specification, the effective volume of the sump should meet the following requirements:
1) For a large sewage pumping station that operates day and night, the effective volume of the sump is calculated based on the water output of not less than 5 and n of the largest pump in the pumping station; if the pump unit is automatically controlled, the high-flow submersible pump must not be activated every hour. More than 6 times; when manual management, the water pump should not be operated more than 3 times per hour.
2) For small sewage pumping stations, because the sewage flow at night is not large, it may stop operating at night. In this case, the volume of the sump must be able to store the inflow during the night stop operation period.
3) For the sump of the sewage pumping station in the factory, its volume should also be reviewed based on the shower drainage volume in a short period of time.
4) The volume of the sump of the sewage cement slurry pump house should be calculated and determined according to the amount of sludge discharged at a time and the pumping capacity of the slurry pump. The volume of the sludge collection tank of the activated sludge pump house should be calculated and determined according to the amount of returned sludge discharged from people, the amount of remaining sludge and the pumping capacity of the sludge pump.
5) In a pump station equipped with a pump control cabinet to automatically control the start and stop of the pump according to the level of the sump, the effective volume can be calculated using the law of the water intake of the sump and the pumping time of each pump, the calculation formula
Vm1n=TminQ/4
Where Vmin is the minimum effective volume of the collecting tank (m3);
Tmin――Minimum working period of the pump (s);
Q――Water pump flow rate (m3/s).
The designed maximum water level of the sump of the sewage pumping station should be calculated according to the fullness of the inlet pipe. The designed average water level shall adopt the water level of the inlet pipe at the design average flow. The designed minimum water level of the sump should meet the requirements of the suction head of the selected water pump. The self-filling pump room should also meet the requirements of the immersion depth of the pump impeller.
Post time: 2021-11-30
