Water pump knowledge, the requirements of the submersible pump technology

Hydraulic components

Pump should be vertical coupling submersible pump; Submersible motor directly connected to the pump impeller coaxial, hydraulic components consist of pump casing, impeller. In order to ensure a steady flow without too much vortex, hydraulic components should be designed and manufactured into no sharp edges. Pump water piping flange should be according to ISO standard nominal pressure 1 mpa shall prevail.

The impeller

Impeller should be no traffic and no overload characteristics of screw centrifugal impeller, positive driving force and centrifugal force with a soft, its long flow channel without sharp corners, and make sure it won’t produce jam impeller in conveying sewage sludge and sludge flocculent structure destruction. Impeller on the hydraulic design, should be with positive driving force and centrifugal force.

Should be carried out to the impeller balance, dynamic balance accuracy should be not less than grade G6.3. Vibration has become no more than 0.45 mm/s.

The motor

Motor should be three-phase squirrel cage motor, three-phase 380 v, 50 hz, IP68 protection grade, F class insulation. The configuration of the motor should be guarantee on H – Q curve in office a little work, do not appear overload, the motor should be able to start 12 times per hour. Pump medium temperature up to 40 ℃, and the average of the stator winding temperature rise shall not exceed 85 ℃.

Should be in the form of cooling of the motor ZhiLengShi, namely water from motor peripheral flow for motor cooling. Don’t rely on pumped cooling loop cooling medium to the way of the cooling system and oil filling machine.

Submersible motor and pump should be from the same manufacturers, random provide protection grade IP68 junction box.

Mechanical seal

In the series of each pump shall be provided, by two independent seal combination sealing system.

Mechanical seal should work in the oil chamber, lets get proper lubrication sealing surface.

Mechanical seal should be free maintenance, lubrication and apart, the liquid to be delivered shall be resistant to thermal shock, and has good characteristics of emergency operation.

Manufacturer shall ensure that the service life of mechanical seal not less than 30000 hours.

Wear-resisting lining

Mud pump in the hydraulic design should be the medium sand only wear of the pump suction part, in any case will not cause wear and tear to the pump casing. Should be in the horn of the pump suction built-in horn wear-resisting lining, and the axial adjustable, in order to keep the high efficiency of the pump, the material shall be the nodular cast iron or 450 brinell hardness of high chromium cast iron. In the daily operation such as must replace the wear-resisting lining, simply remove the pump suction part can be done, but must remove the part of the pump motor. Any other irregular shapes, cannot adjust, change when required to remove the motor and other parts of the design will not be used.

Cable and cable seal

Motor should be used to power control and underwater cables, each cable has a separate entrance, and reliable seal, if the power cable is a multi-core cable, the cable also separately each seal. Cable should be into the wiring room, and use reusable rubber packing seal, do not use the resin or other sealing material sealing cans.

Shaft and bearing

Pump and motor shaft should be the same unit, pump shaft is the motor shaft extension, does not need to also cannot use any of the coupling.

Pump/motor shaft should be supported in high quality permanent lubrication, rolling bearing, the design of the bearing should be enough to bear all the axial and radial force.

Thermal protection

Motor are both each item by the normally closed type temperature sensor protection, three sensors should be in series connection, thermal switches at 70 ℃ or less often closed, jumped at 125 ℃. Thermal switch should be connected to the motor overload protection and connect to the control cabinet, junction box should include a terminal board. Terminal board application of elastic sealing o-ring and motor. Strips long-term fixed threading compression screw methods should be adopted and the connecting cable wires and stator into line.

In order to indicate the bearing wear, at the top and bottom bearing the normally closed type of temperature sensor, the spindle or other components of the motor temperature sensor should be disconnected before severe damage.