Submersible pump motors

For greater depths or as an alternative to the wet-pit design, a submersible pump (Fig. 7b) having a special water-tight motor can be used. 

Significant improvements have occurred in the designs of these motors so that the submersible pump is a rehable option to a wet-pit pump. 

A more economical alternative is found in a submersible pump where the pump, directly coupled with the prime mover, is slid into the tubewell through narrow pipes. Narrow pipes are easy to sink into rocky terrain or very deep water levels. They are less expensive and are easy to install due to the elimination of the need for a pump house. Once the unit is slid into the well it requires little maintenance. (See Figures 7.5-7.7.) Such pumps have a standard centrifugal multistage arrangement, and the motors are required to work under water or any other liquid. These motors have an exclusive application for submersible pumps. 

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. 

A small rating submersible motor Submersible pump and pump in disassembled condition fipeq a... 

Windmills (induction generators) as an unconventional energy source, vertical hollow shaft motors and submersible pump sets, selection of belts for transmission of load, the phenomenon of shaft currents are discussed. 

Electrical System. The conductors in the hose-cable carry power and control signals down to the underwater vehicle and return information. The drive-pump motor is powered by three-phase, 220 V carried down three paired conductors. The solenoid valve, which controls the clean pump, is energized by 24 V direct current (DC), which is controlled on deck. The submersible pump that circulates water through in situ sensors uses 110 V alternating current (AC) power from the hose-cable. 

The pump unit must be designed to operate at very onerous levels of pressure, temperature and in the presence of contaminates such as sand, acids etc. Moreover, the unit must be suitable for lowering into a well-bore which can vary from only 150 to 300 mm in diameter. Due to diametral limitations and the necessary power requirements the motor pump unit itself becomes extensive in length, e.g. up to 10 metres. See Reference 6 for an overview of the subject of submersible pumps. 

Electrical submersible pump coustructiou Coutrol Systems for AC Motors... 

Polybutadiene is also produced in low volume as specialty products. These include low-molecular-weight, liquid 1,2-polybutadienes (60-80%, 1,2 content) used as potting compounds for transformers and submersible electric motors and pumps, liquid trans-1,4-polybutadienes used in protective coatings inside metal cans, and hydroxy-terminated polybutadiene liquid resins for use as a binder and in... 

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. 

Figure 7.8 Sectional arrangement of a submersible squirrel cage motor of 860 kW, 30, 50 Hz, 3.3 kV, 1470 r.p.m. (Weir 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. 

Submersible centrifugal pumps are powered by a cage induction motor due to its maintenance-free design. An example of a flameproof drive unit is... 

Figure 6.99 Submersible centrifugal pump with flameproof cage induction motor. Motor ...

Referat Nr. 5 Nichtrostende Stable bei Tauchmotorpumpen fur Abwasser (Paper no. 5 Stainless steels in submersible motor-driven pumps for sewage) (in German)... 

Kratzer, A. Heumann, A. Wittekindt, W. Tauchmotorpumpen aus korrosions- und verschleissbestandigen Werkstoffen (Submersible motor pumps from corrosion and wear resistant materials) (in German)... 

Schneider, U. A.Ruhm Tauchmotorpumpen Allroimder fiir die Entsorgung und Aufbereitung (Submersible motor-driven pumps Allrounder for disposal and treatment) (in German)... 

Tauchmotorpumpen fiir Abwasser und industrielle Flussigkeiten (Submersible motor pump for waste water and industrial liquids) (in German) wlb wasser, luft und betrieb (1983) 12, p. 15-17... 

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