Guiyang County,is a small town from Hunan Province in China, as the continuous drought and lack of rain, the amount of precipitation is uneven in the north and south, the water-supply source Fangyuan Reservoir and Xiaojiashan Reservoir area did not form effective runoff, and reservoir storage is seriously insufficient. The domestic water is urgently needed for 250,000 people. A new pumping station will be needed, with a designed water lifting capacity of 50,000 tons/day and a construction period of 30 days.
1. Principle of water supply requirements
The operating parameter of pump station is as below:
The inlet level of water tank is controlled at 3-10 meters.
Water supply pressure is controlled at 0.3Mpa-0.5Mpa.
To guarantee the technical requirements, two types of axially split case pump S350B75 and S250A65 can meet its demand which the designed flow is 72-20106m³/h And the head is 11-140 meters. The maximum inlet pressure is 0.6Mpa.
2. Principal of equipped the pump
2.1 The maximum reverse speed of the pump should not exceed 1.2 times of the rated speed. The duration of the rated speed should not exceed 2 minutes. The pump unit should be equipped with spare pumps which can automatically switch alternately for backups.
2.2 The main pump includes working pump and backup pump, but does not include flow regulating pump. The total number of pumps should not exceed ten. The single pump flow rate of the flow regulating pump can be selected as 1/5 or 1/10 of the main pump flow.
According to the equipping principal, we equipped 3 sets of S350B75 and 2 sets of S250A65.