Selection and requirements of submersible sewage pumps

The drainage pumps used in buildings include submersible sewage pumps, submerged drainage pumps, vertical sewage pumps, and horizontal sewage pumps. Due to the small size of the general site within the building and the small drainage volume, submersible sewage pumps and submerged sewage pumps can be preferred for drainage pumps, among which submerged sewage pumps are generally used in important locations; Vertical and horizontal sewage pumps require isolation foundations, self priming water absorption, and occupy a certain amount of space, so they are less commonly used in buildings.
The flow rate of the drainage pump should be selected according to the designed second flow rate of domestic drainage; When there is drainage adjustment, it can be selected based on the maximum hourly flow rate of domestic drainage. The flow rate of the drainage pump in the fire elevator sump shall not be less than 10L/s.
The head of the drainage pump is calculated and determined based on the lifting height and pipeline loss, and then a certain free head is added. The free head should be 0.02-0.03MPa. The flow rate of the suction and discharge pipes of the drainage pump should not be less than 0.7m/s and should not exceed 2.0m/s.
A backup pump should be installed in each domestic drainage collection tank as a unit in public buildings, and should be operated interactively in normal times. For the drainage of basement, equipment room, and garage floor flushing, if there are two or more drainage pumps, pumps may not be used. When the accident drainage pipe cannot be installed in the water collection tank, the water pump should have uninterrupted power supply; When the drainage and inlet pipes can be closed, there may be no uninterrupted power supply, but an alarm device should be installed.
When lifting sewage and wastewater with large impurities, the outlet pipes of submersible sewage pumps in different collection tanks should not be merged and discharged; When lifting general wastewater, it is possible to consider combining the discharge pipes of submersible sewage pumps from different collection tanks according to the actual situation.
When two or more water pumps share a common outlet pipe, valves and check valves should be installed on each water pump outlet pipe. When a single water pump may cause backflow during drainage, a check valve should be installed. It is not allowed to merge pressure drainage pipes with gravity drainage pipes inside the building for drainage.
When the submersible sewage pump contains large debris, it should be equipped with a crushing device; When lifting wastewater containing a large amount of fiber, it is advisable to use a large channel submersible sewage pump.
When the motor power of the submersible sewage pump is greater than or equal to 7.5kW or the outlet pipe diameter is greater than or equal to DN100, a fixed autocoupling device of the water pump can be used; When the motor power of the submersible sewage pump is less than 7.5kW or the outlet pipe diameter is less than DN100, a flexible hose mobile installation can be installed. When a submersible sewage pump is used for drainage in the sewage collection tank, a fixed self coupling device for the water pump should be installed to facilitate the maintenance of the water pump.
The drainage pump should be able to start and stop automatically and manually on site. Multiple water pumps can operate in parallel alternately or in sections.