How many types of Centrifugal pump?

Answer 1

Vertical centrifugal pumpsVertical centrifugal pumps are also referred to as cantilever pumps. They utilize a unique shaft and bearing support configuration that allows the volute to hang in the sump while the bearings are outside of the sump. This style of pump uses no stuffing box to seal the shaft but instead utilizes a "throttle Bushing". A common application for this style of pump is in a parts washer. Froth pumpsIn the mineral industry, or in the extraction of oilsand, froth is generated to separate the rich minerals or bitumen from the sand and clays. Froth contains air that tends to block conventional pumps and cause loss of prime. Over history, industry has developed different ways to deal with this problem. One approach consists of using vertical pumps with a tank. Another approach is to build special pumps with an impeller capable of breaking the air bubbles. In the pulp and paper industry holes are drilled in the impeller. Air escapes to the back of the impeller and a special expeller discharges the air back to the suction tank. The impeller may also feature special small vanes between the primary vanes called split vanes or secondary vanes. Some pumps may feature a large eye, an inducer or recirculation of pressurized froth from the pump discharge back to the suction to break the bubbles. [4] Multistage centrifugal pumpsA centrifugal pump containing two or more impellers is called a multistage centrifugal pump. The impellers may be mounted on the same shaft or on different shafts.

For higher pressures at the outlet impellers can be connected in series. For higher flow output impellers can be connected in parallel.

A common application of the multistage centrifugal pump is the boiler feedwater pump. For example, a 350 MW unit would require two feedpumps in parallel. Each feedpump is a multistage centrifugal pump producing 150 l/s at 21 MPa.

All energy transferred to the fluid is derived from the mechanical energy driving the impeller. This can be measured at isentropic compression, resulting in a slight temperature increase (in addition to the pressure increase).

Energy usageThe energy usage in a pumping installation is determined by the flow required, the height lifted and the length and friction characteristics of the pipeline. The power required to drive a pump (), is defined simply using SI units by: Single-stage radial-flow centrifugal pump

where: is the input power required (W) is the fluid density (kg/m3) is the standard acceleration of gravity (9.80665 m/s2) is the energy Head added to the flow (m) is the flow rate (m3/s) is the efficiency of the pump plant as a decimal

The head added by the pump () is a sum of the static lift, the head loss due to friction and any losses due to valves or pipe bends all expressed in metres of fluid. Power is more commonly expressed as kilowatts (103 W, kW) or horsepower (kW = hp*0.746). The value for the pump efficiency, , may be stated for the pump itself or as a combined efficiency of the pump and motor system.

The energy usage is determined by multiplying the power requirement by the length of time the pump is operating