Analysis of the current development status of pump technology at home and abroad

Pumps and Their Role in the National Economy Pumps have evolved alongside industrial development. As early as the 19th century, relatively complete types and varieties of pumps were available abroad and widely used. According to statistics, around 1880, centrifugal pumps for general purposes accounted for over 90% of the total pump output, while pumps for special purposes—such as those for power units, chemical industry, and mining—made up only about 10%. By 1960, general-purpose pumps accounted for just 45%, and special-purpose pumps had risen to 55%. Based on current development trends, the proportion of special-purpose pumps will further surpass that of general-purpose pumps.

As early as the early 20th century, submersible electric pumps were first successfully developed in the United States to replace deep-well pumps. Subsequently, Western European countries also began researching and developing them, making continuous improvements to gradually perfect the technology. For example, the Rhine Brown Coal Mine in Germany used over 2,500 submersible electric pumps of various types, with the largest having a capacity of 1,600 kW and a head of 410 meters.

China’s submersible electric pumps began to develop in the 1960s. Among them, working-face submersible electric pumps have long been used for farmland irrigation in southern China. Medium and small-capacity submersible electric pumps have been developed into series and put into mass production. Large-capacity, high-voltage submersible electric pumps and submersible motors have also been launched one after another; large-scale submersible electric pumps with a capacity of 500–1,200 kW have been put into operation in mines. For instance, the Yanshan Open-pit Iron Mine of Anshan Iron and Steel Company uses 500 kW submersible electric pumps for drainage, which have achieved remarkable results during the rainy season. There are signs that the use of submersible electric pumps will bring changes to mine drainage equipment and that they are likely to replace traditional large horizontal pumps. In addition, submersible electric pumps with larger capacities are currently under trial production.

Machines used to suck, transport liquids, and increase liquid pressure are generally collectively referred to as pumps. From an energy perspective, a pump is an energy-conversion machine that converts the mechanical energy of a prime mover into the energy of the transported liquid, increasing the liquid’s flow rate and pressure.

Pumps are generally used to suck liquids from lower-lying areas and transport them through pipelines to higher-lying areas. For example, in daily life, we see pumps used to draw water from rivers or ponds for farmland irrigation; another example is pumping water from deep underground wells and delivering it to water towers. Since the pressure of a liquid can be increased after passing through a pump, pumps can also be used to suck liquids from low-pressure containers and transport them to high-pressure containers or other required locations while overcoming resistance along the way. For instance, boiler feed pumps draw water from low-pressure water tanks and supply it to the high-pressure boiler drum.

Pumps have a wide range of performance: the flow rate of giant pumps can reach hundreds of thousands of cubic meters per hour, while that of micro-pumps can be less than tens of milliliters per hour. Their pressure can range from normal pressure to over 1,000 MPa. The temperature of the liquids they transport can be as low as below -200°C and as high as above 800°C. Pumps can transport a variety of liquids, including water (clean water, sewage, etc.), oil, acid-alkali solutions, emulsions, suspensions, and liquid metals.

Since most pumps people see in daily life are used to transport water, they are commonly referred to as "water pumps" out of habit. However, this term is obviously incomplete if used as a general name for all pumps.

In fact, pumps have an extremely wide range of applications: from aircraft and rockets in the sky to underground drilling and mining; from trains and tanks on land to ships at sea; and across heavy industry and light industry, cutting-edge science and technology, and daily life—pumps are needed everywhere, and their operation can be seen everywhere. Pumps are required in all sectors of the national economy. If a pump breaks down, it will directly affect production, and in severe cases, cause production shutdowns. For example, in the production processes of the chemical and petroleum industries, most raw materials, semi-finished products, and finished products are liquids. Pumps play a role in transporting these liquids and providing the pressure and flow rate required for chemical reactions; in many devices, they are also used to adjust temperature. If a pump malfunctions, the entire system often stops working. Therefore, some people compare the role of pumps to the "heart" of chemical production processes. At the same time, the quality of pumps directly affects the normal progress of production, making pumps one of the key pieces of equipment in the chemical and petroleum sectors. In addition, the liquids handled in the chemical and petroleum industries are relatively special: some are volatile, flammable, explosive, or toxic; some are highly corrosive or viscous; some need to be transported under high temperature, high pressure, low temperature, or low pressure. Accordingly, these liquids require special pumps to meet the demands, and the required quantity is also large.

In the mining and metallurgical industries, pumps are one of the indispensable pieces of equipment. During mine drainage, if a pump fails, the mine is at risk of being flooded. In addition, during mine production, pumps consume a large amount of electricity—they are the most power-hungry equipment in the entire mine, generally accounting for 20%–40% of the mine’s total electricity consumption, and up to 50% in some individual mines. Especially in recent years, with frequent coal mine accidents in China, pumps have been operating under even greater intensity. Pumps are also indispensable in mineral processing, smelting, and rolling processes. For example, iron and steel plants use pumps to supply water, and any interruption in water supply will damage production equipment and cause major accidents.

In the power generation sector, pumps also play a crucial role. For instance, thermal power plants require a large number of pumps, such as boiler feed pumps, condensate pumps, circulating water pumps, and ash-slag pumps—among which boiler feed pumps are the most power-consuming equipment in power plants.

In the shipbuilding industry, each ocean-going ship uses approximately one hundred pumps of various types, such as marine centrifugal pumps, vortex pumps, marine electric gear pumps, high-pressure gear pumps, marine screw pumps (electric single-screw, double-screw, and triple-screw pumps), marine water-jet propulsion mixed-flow pumps, and axial flow pumps. National defense construction is also inseparable from pumps: the rotation of warship and tank turrets, and the diving and surfacing of submarines all require pumps. In nuclear power plants, nuclear reactors, and rocket and missile bases, not only are pumps needed, but they also have many special requirements (e.g., being able to transport high-temperature, high-pressure, and radioactive liquids, and some even require zero leakage).

In modern water supply and drainage projects, the textile industry (for transporting bleaching liquids and dyes), the paper industry (for transporting pulp), and the food industry (for transporting milk and sugar-based foods)—all require a large number of pumps.

It is thus clear that pumps are not only widely used in all sectors of the national economy but also occupy an important position and play a vital role. Pumps are one of the indispensable mechanical devices for the development of all industries. Therefore, the maintenance of pump equipment is of great importance.