Pump | Types, Applications & Benefits

What is pump?

“Pump” can refer to various things depending on context. It could be a device that moves fluids, like a water pump, or in a fitness context, it might relate to a workout that involves repetitive muscle contractions. Can you provide more details for a specific meaning?

Function of pump

A pump is a mechanical device designed to move fluids, such as liquids or gases, from one place to another. It works by creating a flow and increasing the pressure of the fluid to facilitate its transportation. Pumps are widely used in various applications, including water supply, wastewater treatment, oil and gas industries, and many manufacturing processes. They play a crucial role in maintaining the flow of liquids or gases in different systems.

Positive displacement pumps, which lift a given volume for each cycle of operation, can be divided into two main classes, reciprocating and rotary. Reciprocating pumps include piston, plunger, and diaphragm types; rotary pumps include gear, lobe, screw, vane, and cam pumps.

What is Positive and Negative Displacement Pump?

A positive displacement pump is a type of pump that moves a fluid by trapping a fixed volume and forcing it through the system. They are often used in hydraulic systems, can tolerate high pressures, and provide steady, pulsation-free flow. Negative displacement pumps, on the other hand, draw liquid into an intake and seal it before pushing the liquid out. These are usually less efficient than positive displacement pumps but offer higher pressure output ratios.

Reciprocating positive displacement pumps

A Reciprocating Positive Displacement pump works by the repeated back-and-forth movement (strokes) of either a piston, plunger or diaphragm

piston pump, the first stroke of the piston creates a vacuum, opens an inlet valve, closes the outlet valve and draws fluid into the piston chamber (the suction phase). As the motion of the piston reverses, the inlet valve, now under pressure, is closed and the outlet valve opens allowing the fluid contained in the piston chamber to be discharged (the compression phase). The bicycle pump is a simple example. Piston pumps can also be double acting with inlet and outlet valves on both sides of the piston. While the piston is in suction on one side, it is in compression on the other. More complex, radial versions are often used in industrial applications.

Plunger pumps operate in a similar way. The volume of fluid moved by a piston pump depends on the cylinder volume; in a plunger pump it depends on the plunger size. The seal around the piston or plunger is important to maintain the pumping action and to avoid leaks. In general, a plunger pump seal is easier to maintain since it is stationary at the top of the pump cylinder whereas the seal around a piston is repeatedly moving up and down inside the pump chamber.

A diaphragm pump uses a flexible membrane instead of a piston or plunger to move fluid. By expanding the diaphragm, the volume of the pumping chamber is increased and fluid is drawn into the pump. Compressing the diaphragm decreases the volume and expels some fluid. Diaphragm pumps have the advantage of being hermetically sealed systems making them ideal for pumping hazardous fluids.

Rotary positive displacement pumps

Rotary positive displacement pumps use the actions of rotating cogs or gears to transfer fluids, rather than the backwards and forwards motion of reciprocating pumps. The rotating element develops a liquid seal with the pump casing and creates suction at the pump inlet. Fluid, drawn into the pump, is enclosed within the teeth of its rotating cogs or gears and transferred to the discharge. The simplest example of a rotary positive displacement pump is the gear pump. There are two basic designs of gear pump: external and internal.

An external gear pump consists of two interlocking gears supported by separate shafts (one or both of these shafts may be driven). Rotation of the gears traps the fluid between the teeth moving it from the inlet, to the discharge, around the casing. No fluid is transferred back through the center, between the gears, because they are interlocked. Close tolerances between the gears and the casing allow the pump to develop suction at the inlet and prevent fluid from leaking back from the discharge side. Leakage or “slippage” is more likely with low viscosity liquids.

An internal gear pump operates on the same principle but the two interlocking gears are of different sizes with one rotating inside the other. The cavities between the two gears are filled with fluid at the inlet and transported around to the discharge port, where it is expelled by the action of the smaller gear.

Type of pump

There are several types of pumps, each designed for specific applications. Some common types include:

1. Centrifugal Pumps: These pumps use a rotating impeller to increase the fluid’s velocity, creating a flow. They are commonly used for water supply and irrigation.

Application

– Water supply for buildings and municipalities
– Irrigation systems
– Cooling systems in industrial processes

2. Reciprocating Pumps: These pumps use a piston or diaphragm to move fluid in and out of a chamber. Examples include piston pumps and plunger pumps.

Application

– Hydraulic systems
– High-pressure cleaning systems
– Oil and gas processing

3. Rotary Pumps: These pumps operate by trapping fluid between rotating components. Examples include gear pumps, vane pumps, and screw pumps.

Application

– Lubrication systems
– Fuel transfer in automotive and aviation
– Chemical processing

4. Diaphragm Pumps: These pumps use a flexible diaphragm to displace the fluid. They are often used in applications requiring precise control.

Application

– Pharmaceuticals and biotechnology processes
– Metering and dosing applications
– Handling corrosive or abrasive fluids

5. Submersible Pumps: Designed to be submerged in the fluid they are pumping,

commonly used for sewage, drainage, and deep-well water supply.

Application

– Deep-well water supply
– Wastewater treatment
– Sump pump applications in basements

6. Peristaltic Pumps: These pumps use a flexible tube squeezed by rollers to move fluids. They are often used for pumping sensitive or abrasive fluids.

Application

– Medical and analytical instrumentation
– Food and beverage processing
– Chemical dosing in water treatment

7. Axial Flow Pumps: Suitable for large flow rates with low head applications, they move fluid parallel to the pump shaft.

Application

– Flood control and drainage
– Agricultural irrigation
– Aquaculture systems

8. Jet Pumps: These pumps use a jet of high-speed fluid to create a low-pressure area,

drawing in the fluid to be pumped.

Application

– Domestic water wells
– Shallow-depth pumping
– Industrial and agricultural water supply

The choice of pump depends on factors such as the type of fluid, required flow rate, pressure, and the specific application.

 

FAQ for pumps

Q1: What is a pump?
A: A pump is a mechanical device designed to move fluids, such as liquids or gases, from one place to another by creating a flow and increasing fluid pressure.

Q2: How do pumps work?
A: Pumps work by using mechanical action to add energy to the fluid, increasing its velocity or pressure, enabling the fluid to be transported.

Q3: What are the common types of pumps?
A: Common types include centrifugal pumps, reciprocating pumps, rotary pumps, diaphragm pumps, submersible pumps, peristaltic pumps, axial flow pumps, and jet pumps.

Q4: Where are centrifugal pumps used?
A: Centrifugal pumps are commonly used for water supply, irrigation, and in cooling systems for various industrial processes.

Q5: What are reciprocating pumps suitable for?
A: Reciprocating pumps are suitable for hydraulic systems, high-pressure cleaning, and applications in oil and gas processing.

Q6: In what applications are rotary pumps employed?
A: Rotary pumps are used in lubrication systems, fuel transfer, and various chemical processing applications.

Q7: Where are diaphragm pumps commonly used?
A: Diaphragm pumps find applications in pharmaceuticals, biotechnology processes, and handling corrosive or abrasive fluids.

Q8: What are submersible pumps used for?
A: Submersible pumps are designed for deep-well water supply, wastewater treatment, and sump pump applications in basements.

Q9: What industries use peristaltic pumps?
A: Peristaltic pumps are used in medical and analytical instrumentation, food and beverage processing, and chemical dosing in water treatment.

Q10: Where are axial flow pumps employed?
A: Axial flow pumps are used in flood control, agricultural irrigation, and aquaculture systems.

Q11: What is the typical application of jet pumps?
A: Jet pumps are commonly used for domestic water wells, shallow-depth pumping, and in industrial and agricultural water supply.

These FAQs provide a brief overview of pumps, their types, and common applications in various industries.