Centrifugal vertical pumps are also called cantilever pumps. They use a unique tree and configuring bearing support which allows the casing to hang in the pit while the bearings are outside the sump. This style of pump use gland to seal the shaft but uses a “bottleneck socket”. A common application for this style of pump is in a parts washer.
A centrifugal pump containing two or more wheels is called a multistage centrifugal pump. The wheels can be mounted on the same shaft or on different trees. For pressures higher output, the wheels can be connected in series. For the output of higher throughput, the wheels can be connected in parallel.
A common application of the multistage centrifugal pump is the boiler feed water pump. For example, a 350 MW unit, should be two feedpumps in parallel. Each supply is a multicellular pump produce 150 l / s at 21 MPa. All of the energy transferred to the fluid is derived from the mechanical energy of the rotor drive. This can be measured to isentropic compression, resulting in a slight increase in temperature (in addition to the increase in pressure).
In the mining industry, or in the extraction of oil sands, the foam is generated to separate bitumen from sand and clays and minerals. Foam contains air that tends to block the conventional pumps and cause a loss of prime. Historically, the industry has developed ways to cope with this problem. In the industry of pulp and paper holes are drilled in the wheel. Air escapes on the back of the wheel and a special expeller evacuates the air to the suction tank. The wheel can also featured small special fins between the primary blades called blades cracked or secondary blades. Some pumps may have a large eye, inducer or recirculation of foam under pressure of the pump back to the aspiration to break bubbles.