Understanding Industrial Pumps: Types, Operations, and Key Features

What is a Pump?

A pump moves liquid substances through their mechanical action. Traditionally, pumps can be divided into three main types based on the methods used by those pumps to move the fluid.

Classifications

These three types depending on how they move the fluid, namely direct lift, displacement, and gravity methods. Therefore, there are corresponding direct lift pumps, displacement pumps, and gravity pumps with different parts designs. Pumps are usually operated by reciprocating or rotating mechanisms, and consume energy to perform mechanical work that moves the fluid with different parts triggering. Industrial pumps work by these three mechanisms is highly popular as these processes do the pumping process by different advantages.

The mechanical industrial pumps can also be submerged in the fluid pumped by the pumps or placed outside the fluid. The pumps can be divided into positive displacement pumps, impulse pumps, velocity pumps, gravity pumps, steam pumps, and valve-less pumps according to their displacement method. In addition, there are two basic types of pumps, namely positive displacement pumps and centrifugal pumps.

 

What Drives a Pump?

Broadly speaking, the pump can use many kinds of power (energy) to run, such as manpower, electricity, and even wind power. These energy sources can be a variety of equipment, varying in size, from a micro microscope for medical use to a large industrial pump in a water supply system for pumping process, or industrial pumps used to transfer coolant in machineries. Those kind of industrial pumps has to be resistant to the corrosion effect while they are in the pumping process.

Industrial pumps have a wide range of pumping applications, such as the process of pumping water from wells, aquarium filtration work, pond filtration tasks, water cooling and fuel injection in the automotive industry, and oil and gas operations in the energy industry. In the field of machine tools, industrial pumps are used to move cutting fluids and coolants. Pumps are used in the biochemical process of developing and manufacturing drugs. They are often used as artificial substitutes for human body parts, especially artificial hearts and penile prostheses.

 

Impeller Numbers

The number of impellers determines the working mode of the pump and the strength of liquid delivery. A pump that contains only one revolving impeller is called a single-stage pump. A pump containing two or more revolving impellers is called a double-stage pump or a multi-stage pump.

In applications in the biological field, many different types of chemical pumps and biomechanical pumps have been developed. BIOMIMICRY is sometimes used in the development of new mechanical pumps. Just like in the early days, people tried to study birds in order to make humans fly. Through such efforts, although not always successful, there are many biological imitation cases that help to enhance the level of scientific research.

 

Positive Displacement

A positive displacement pump draws a fixed amount of liquid and forces it to drain into a discharge pipe to make the liquid flow. Generally, positive displacement pumps use expanding cavity on the suction side and decreasing cavity on the discharge side. With this method, when the cavity on the suction side expands, the liquid flows into the pump, and when the cavity collapses, the liquid flows out from the discharge port. In each cycle, the amount of liquid is constant.

 

Safety Issue of Positive Displacement Method

Unlike centrifugal pumps, positive displacement pumps can produce the same flow rate at a given speed, regardless of the discharge pressure. Therefore, the positive displacement pump belongs to a kind of constant flow pump equipment.

However, at the same time, as the pressure increases, the internal leakage will increase slightly, thereby preventing a truly constant flow. That is, since the positive displacement pump does not have a closing valve like a centrifugal pump, the positive displacement pump cannot work against the closed valve on the discharge side of the pump. Therefore, the positive displacement pump continues to generate flow under the action of the closed discharge valve, and the pressure in the discharge line continues to increase until the line bursts, severely damaging the pump.

 

What is Necessary?

Based on safety considerations, it is necessary to install a relief or safety valve on the discharge side of the positive displacement pump. Pump manufacturers and industrial users should pay attention to this issue. The relief valve can be either internal or external. Pump manufacturers can usually choose to provide internal relief or safety valves.