Submersible turbine pumps

Submersible turbine pumps are a variety of vertical turbine pumps with the motor attached below the pumping unit. Water passes in through an intake port located between the motor and bowl assembly, then upward through the bowl stages to the surface through the pump pipe. Electric power is supplied to the motor by specially insulated wires. Submersible turbine pumps are manufactured for water supply and oil well usage by a wide variety of manufactures in sizes ranging from /3 to several hundred horsepower, and are constructed of materials suited for many chemicals. 

After a recovery-remediation well has been constructed and tested for well capacity, an appropriate submersible pump may be installed. Materials of construction must be compatible with the fluids to be pumped (water, oil, silt/sand). Most 

FIGURE 7.13 Photograph showing aboveground wellhead and control box for one-pump LNAPL recovery system. 

A recent innovation to improve recovery functions is a variable-speed submersible pump. When used with electronic controls, it is possible to select a fluid surface elevation and adjust the pumping rate periodically to maintain that fluid level at that elevation. Another adaptation of existing control technology uses an electrically adjustable valve to throttle the pump output. As the fluid level declines, the throttle restricts flow to prevent a further decline. 

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These motors have a lower efficiency as a result of running in liquid, causing more liquid drag and also axial thrust bearing loss, which is also a part of the motor. However, this lower efficiency of the motor is compensated by fewer mechanical and hydraulic losses in a submersible motor-pump installation, compared to a vertical turbine pump installation. 

You can only raise a column of cold water in a pipe a maximum of. S.S.9 ft with a pump in suction lift. Beyond 34 ft, the water will boil or vaporize. This is the reason why submersible pumps and vertical turbine pumps exist. I here is no limit to the distanee you can push a liquid from below, but you can only a.spirate a liquid a maximum of 34 ft from below the pump. 

Where a significant lift is required such as offshore, several options are available such as a shaft driven, hydraulic drive or electrical submersible pump. Shaft driven vertical turbine pumps historically have been used extensively offshore, but recent reliability improvement with electrical submersible pumps and hydraulic drive units have been eagerly accepted as they eliminate alignment problems, topsides weight and in some instances are less complex than the right angle engine driven vertical turbine units. Hydraulic calculations for offshore pump installations must remember to account for tide and wave fluctuations. 

One-pump systems Submersible turbine Moderate to high Unlimited Yes Yes ... 

The only feature shared by all of these is a single intake port. General pumps used are submersible turbine (electric) and mechanical-lift pumps. 

Vertical intake wells eonsist of a nonmetaUic casting [typically, fiberglass-reinforced pipe (FRP) or polyvinyl chloride (PVC)], proper-grade stainless steel well screen (if needed), and a stainless steel submersible or vertical turbine pump (see Fig. 3.2). These wells are usually less costly than the horizontal wells, but their yield is relatively small (typieaUy 400-4000 m /day). 

The application and use of deep-well turbine and submersible pumps, is extensive and a choice will depend upon the depth of liquid and the rate of discharge. In rocky areas, where the digging of larger well cavity is a difficult task, submersible pumps provide an easy alternative. Similarly, for higher heads and where only a small quantity of liquid is to be pumped, these pumps are preferred. We discuss below the characteristics of these motors and the application of these pumps. 

Dewatering pumps A dewatering process involves using a centrifugal pump (submersible or vertical turbine) to remove water from a construction site, pond, mine shaft, or any other area. 

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