A pump is a device that moves a fluid (liquid or gas), or sometimes slows it down by mechanical action, usually converting it from electrical energy into hydraulic energy. Pumps have three major classes according to the method of liquid movement: gravity pumps, displacement, and direct lift pumps.
Pumps drive by certain machines and use the power to perform the function of conveying the liquid. Power pumps use for a variety of power systems. Wind power, engines, power, or manual operation pumps comes in many sizes from large industrial pumps for use in medical systems.
Mechanical pumps provide a variety of applications for pumping and cooling oil and natural gas in the fuel industry, from wells, aquarium filters, filtering ponds, and car pumps, to water cooling and fuel injection pumps. In the medical field, pumps are used to make and produce drugs for chemical processes. These also use as an alternative to implants, especially in artificial hearts and prostheses.
Classification of pumps
There are many types of pumps but the pump has two main types. However, all such classifications are limited in scope and largely overlapping to each other. A more basic system of pump classification is based on the principle of adding energy to a fluid. So, the pump has the following types:
- Dynamic (centrifugal) pump – In this pump, power is constantly added to increase the speed of the fluid in the pump.
- Positive Displacement Pump – In this pump, power adds by applying force to one or more moving boundaries of enclosed, fluid-containing volumes.
These are further subdivided into several forms. We will discuss these several forms separately in different articles for article simplification.
The positive-displacement pump divides into some more types that are given below in details:
1) Rotary Positive-Displacement Pump:
These pumps move the fluid using a rotating mechanism, which creates a vacuum that traps and attracts the fluid.
Advantage: Rotary pumps work very efficiently because they can handle high viscous fluids with a high flow rate as the viscosity increases.
Disadvantages: The nature of the pump requires a very close clearance between the rotating pump and the outer edge, which allows it to rotate at a slow, constant speed. If the rotary pumps operate at high speeds, the fluids will cause erosion, which will eventually lead to a clearance of the liquid passing through, reducing efficiency.
2) Reciprocating positive-displacement pump:
Reciprocating pumps move liquid by utilizing more than one oscillating diaphragm, plunger or piston, but the valve stops the motion of liquid in the required path. For suction to occur, the pump must first pull the plunger in external motion to reduce the pressure in the chamber. After pushing the plunger back, it raises the pressure chamber and the internal pressure of the plunger. After this process, the discharge valve opens and releases the fluid into the distribution pipe at high speed.
Pumps in this category are simplex, single-cylinder, in some cases quad (four) or more cylinders. This may a single operation by pulling on one side of the piston movement and delivery to the other side. Pumps can operate by hand, by air or steam, or by an engine-driven belt. This type of pump widely used in the 19th century – in the early days of steam operation: as a water pump for water supply. Rotating pumps now generally deliver higher concentrations. For example, concrete and heavy fuel pumps use for applications that require a lower flow rate when resisting high resistance. Hand-operated hand pumps have been used to deliver water to wells. Standard bicycle pumps and foot pumps use a combination of inflation.
On the inlet side, this pump has an increased cavity and a decreasing cavity on the outlet section. As the cavity expands towards the suction fluid flows into the pumps. So as the cavity collapses the fluid comes out of the discharge. Volume assigns to each cycle of continuous operation. The volumetric efficiency of the pump can achieve by routine maintenance and inspection of its valves.
3) Peristaltic pumps:
In this kind, the liquid inside the flexible tubes fixes in circular pump’s housings. Many rollers, shoes, or wipers attached to the rotor press the flexible hose. When the Rotor turns, part of the tube closes (or loosens) under pressure, forcing the liquid through a pipe. In addition, when the pump opens to its natural state after passing through the cam, the fluid in the pump (re-position installation) is attracted.