- Posted on
- noori
Recently submersible pumps have gaint good market shares in both the industrial and domestric sectors.
Due to their high versatility and reliability, they need no priming, they are not prone to the issue of cavitation, and are very efficient. The submersible pump is a centrifugal pump,you can see how the impellers throwing the water outwards.The impelling blades r the backwards curved type. Here, many of the impellers are connected onto a single shaft,and this shaft is driven by an induction motor,the water enters through the eyes of impellers, and they are then throw out radially due to centrifugal action. This way,the water particles gain both kinetic and pressure energy, now we need to pass this outlet water to the next impeller efficiently.
A stationary device called a diffuser is used for this purpose,you can see how the water flowing from the impeller enters the diffuser, the diffuser then defkects the inlet water and makes it ready for the next impeller stage. The naext impeller is connected to the outlet of the difuser, the series of connected impellers, multiplies the pressure gain at each stage. This is the reason why submersible pumps produce a huge amount of pressure head.
The water so pumped ,passes through an inbuilt non slam check valve of the submersible pump,the issue of water hammer is effectively reduced by the non slam check valve ,which is a huge issue in high altitude pumping.Now lets focus on the prime mover of a submersible pump. Generally,an induction motor is used to run the impellers. The power supply to an induction motor is given to the stator ,which can be either single phase or three phase.The motor produces a lot of heat during operation.And due to this reason, the motor is either water or oil filled for effective cooling. The continuously circulating cooling jacket around the motor makes sure that the motor never overheats . You can see how a small impeller at the bottom maintains this circulating flow of coolant. The entire impeller motor assembly is immersed in the working fluid, this means that just as with conventional centrifugal pumps, priming is not needed in submersible pumps.
Another major issue faced by normal centrifugal pumps is the issue of cavitataion. One of the main reasons for this happening is the low pressure on the suction side. In submersible pumps,the water is pushed rather than pulled, and this reduce the chance of negative pressure head in the system, and thus the issue of cavitataion does not occur. The high pressure head, flow rate characteristics, and the ability for it to be immersed completely in the water, make submersible pumps an ideal choice for bore well lifting, fire fighting oil well lifting. 90% of the oil wells in the world require some kind of artificial lift to achieve an economic flow rate, there was no narrow flow region in the impeller and diffuser section of submersible pumps . And this fact, also makes submersible pumps the ideal choice for waste water pumping and lifting highly viscus fluids. Moreover ,with the specialized design, submersible pumps can be even used for slurry pumping. (Click here to get more infomation and products of pump,such as water pump,etc.)
We hope this essey give u a clear insight into the working of submersible pumps. Thank you.