Driven by motor, the pump body and inlet line are filled with liquid before starting the pump. With high-speed rotation, the impeller drives the liquid between the vanes to rotate together. Due to the effect of centrifugal force, the liquid is thrown to the outer edge of impeller from the impeller center with kinetic energy increased. After the liquid entering the pump shell, as the flow channel in the volute type pump shell is gradually enlarged, the liquid velocity is decreased gradually, which makes part of the kinetic energy transform into static energy, therefore the liquid with high pressure is discharged along the outlet. At the same time, the impeller center forms a certain vacuum for th at the liquid is thrown out. The pressure on liquid level is higher than that of impeller center, so the liquid in suction pipe will flow into the pump under the action of pressure difference. With the constant rotation of impeller, the liquid is sucked and extruded continuously.
Ever since 2000 BC when the Egyptians invented the shadoof, a pump used to draw water from wells, the pump has been a key component of everyday life. Here are several types of pumps invented since then, along with some of their most common applications. The wide variety of pumps for today made it impossible for us to include them all.
The main parts, a centrifugal pump consist of are casing, impeller, shaft, bearing, and sealing.
Within the petroleum industry centrifugal pumps are necessary in order to process fluids especially hydrocarbons. Another important application within the petroleum industry is in the mud circuit on a drilling rig. On drilling rigs, mud which consists mainly of water and bentonite as well as of several different additives depending on many different factors is used. The heart of the mud circuit is the mud pump which is in general a high pressure piston pump. It provides the major part of head to overcome the system’s resistance. The mud is pumped through a piping system to the derrick and through the standpipe to a definite high. Now through the kelly hose via the gooseneck into the upper kelly cock. It flows through the Kelly and the lower kelly cock into the drill string down the borehole. At its end, the mud leaves the drilling collars through the drilling bit.