Main Difference – Centrifugal vs. Reciprocating Pump
Pumps are mechanical devices that use suction or pressure to move fluids. There is a variety of different types of pumps which are used in different situations. The main difference between centrifugal and reciprocating pump is that, in centrifugal pumps, the fluid is continuously accelerated by a set of impeller blades whereas, in reciprocating pumps, the periodic motion of a piston draws in and discharges fluid. Reciprocating pumps discharge fluid in pulses, with each pulse discharging a fixed volume of fluid.
What is a Centrifugal Pump
A centrifugal pump is described as a type of kinetic pump, i.e. a pump which increases the fluid’s speed and gives kinetic energy to the fluid. Eventually, the kinetic energy in the fluid is converted to pressure energy, which is used to expel the fluid. In centrifugal pumps, a rotating impeller is used to accelerate the fluid. Fluid may enter a centrifugal pump radially or axially. In centrifugal pumps with radial flow, fluid enters at the centre of the rotating blades. The fluid is then accelerated along the rotating impeller blades. Eventually, the fluid exits perpendicularly to the shaft. In centrifugal pumps with axial flow, fluid is accelerated parallel to the shaft.
Centrifugal pumps are the most common types of pumps in use. They are used, for example, to pump water for domestic water supplies.
A Centrifugal Pump
What is a Reciprocating Pump
A reciprocating pump is a type of positive displacement pump, which operates by trapping a fixed volume of liquid and then forcing it out using mechanical pressure. Reciprocating pumps consist of a cylinder with two valves at the opposite ends and a piston which operates along a cylinder in a connected cavity.
During the suction stroke, the piston moves back, increasing the volume inside the cylinders and dropping the pressure. This causes the inlet valves to open and for the fluid to flow in. Next, during the discharge stroke, the piston reverses its direction and starts pushing on the fluid. With the volume inside the cylinders decreasing, the fluid’s pressure rises. This time, the outlet valves open up and fluid is discharged.
Reciprocating pumps are typically used to pump fluids with high viscosity.
Difference Between Centrifugal and Reciprocating Pump
Definition
Centrifugal pump is a type of kinetic pump, which increases the fluid’s speed and gives kinetic energy to the fluid, and that is then converted to pressure energy and used to expel the fluid.
Reciprocating pump is a type of positive displacement pump, which operates by trapping a fixed volume of liquid and then forcing it out using mechanical pressure.
Fluid Discharge
Centrifugal pump discharges fluid continuously.
Reciprocating pump discharges fluid in pulses.
Efficiency of the Pumps
Centrifugal pumps are less efficient compared to reciprocating pumps.
Reciprocating pumps are more efficient compared to centrifugal pumps.
Pressure (“Head”)
In Centrifugal pumps, as flow rate increases, the pressure remains nearly constant and then drops off.
In Reciprocating pumps, the flow rate is nearly constant regardless of the pressure.
Viscosity
In Centrifugal pumps, as viscosity increases, the flow rate decreases.
In Reciprocating pumps, raising the viscosity of fluid does not have a significant effect on the flow rate. In fact, the flow rate may slightly increase.
