History and culture of the hottest pump

2022-09-27
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History and culture of pumps

pumps are machines that deliver or pressurize liquids. It transmits the mechanical energy or other external energy of the prime mover to the liquid to increase the energy of the liquid. The pump is mainly used to transport liquids, including water, oil, acid-base liquid, emulsion, suspended lotion and liquid metal, as well as liquids, gas mixtures and liquids containing suspended solids

the improvement of water is very important for human life and production. In ancient times, there were various water lifting appliances, such as Egyptian chain pump (17th century BC), Chinese orange cone (17th century BC), windlass (11th century BC) and waterwheel (1st century BC). More famous is the screw rod invented by Archimedes in the third century BC, which can steadily and continuously lift water to a height of several meters. Its principle is still used by modern screw pumps

around 200 BC, the fire pump invented by the ancient Greek craftsman Ctesibius is the most primitive piston pump, which already has the main components of a typical piston pump, but the piston pump developed rapidly only after the emergence of the steam engine

From 1840 to 1850, Worthington of the United States invented the piston pump with the pump cylinder opposite the steam cylinder and the direct action of steam, marking the formation of modern piston pump. The 19th century was the climax of the development of piston pumps, which had been used in hydraulic presses and other machinery. However, with the sharp increase in water demand, since the 1920s, low-speed piston pumps with greatly limited flow have gradually been replaced by high-speed centrifugal pumps and rotary pumps. However, in the field of high pressure and small flow, reciprocating pumps still occupy a major position, especially diaphragm pumps and plunger pumps, which have unique advantages and are increasingly used

the emergence of rotary pump is related to the increasingly diversified requirements for liquid transportation in industry. As early as 1588, there was a record about the four vane sliding vane pump, and then there were other kinds of rotary pumps, but until the 19th century, the rotary pump still had the shortcomings of large leakage, large wear and low efficiency. At the beginning of the 20th century, people solved the problems of rotor lubrication and sealing, and used high-speed motor drive. Rotary pumps suitable for high pressure, small and medium flow and various viscous liquids developed rapidly. The types of rotary pumps and the types of liquids suitable for delivery are more than other types of pumps

the idea of using centrifugal force to carry water first appeared in the sketch made by Leonardo da Vinci. In 1689, French physicist Papan invented the volute centrifugal pump with four blade impeller. But closer to the modern centrifugal pump is the so-called Massachusetts pump with radial straight blades, semi open double suction impeller and volute, which appeared in the United States in 1818. From 1851 to 1875, multistage centrifugal pumps with guide vanes were invented one after another, making it possible to develop high head centrifugal pumps

although as early as 1754, the Swiss mathematician Euler put forward the basic equation of impeller hydraulic machinery, which laid the theoretical foundation for the design of centrifugal pump, its advantages were not brought into full play until the end of the 19th century, when PC material became the first choice for automotive lighting systems, and the invention of plastic high-speed motor made the centrifugal pump obtain the ideal power source. On the basis of the theoretical research and practice of many scholars such as Renault in the UK and pfederer in Germany, the efficiency of centrifugal pump has been greatly improved, and its performance range and application field are also expanding day by day. It has become the pump with the widest application and the largest output in modern times

pumps are usually divided into positive displacement pumps, power pumps and other types of pumps according to the working principle, such as jet pumps, water hammer pumps, electromagnetic pumps, gas lift pumps. Pumps can be classified and named by other methods in addition to their working principles. For example, according to the driving method, it can be divided into electric pump and hydraulic pump; According to the structure, it can be divided into single-stage pump and multi-stage centrifugal pump; According to the purpose, it can be divided into boiler feed pump and metering pump; According to the nature of the transported liquid, it can be divided into water pump, oil pump and mud pump

The positive displacement pump relies on the working elements to make reciprocating or rotary motion in the pump cylinder, so that the working volume can be increased and reduced alternately, so as to realize the suction and discharge of liquid. The positive displacement pump with reciprocating motion of working elements is called reciprocating pump, and the one with rotary motion is called rotary pump. The suction and discharge processes of the former are carried out alternately in the same pump cylinder, and are controlled by the suction valve and discharge valve; The latter forces the liquid to transfer from the suction side to the discharge side through the rotation of working elements such as gears, screws, leaf rotors or slides. The flange ball valve

is measured at several positions 1.5m above the ground

the flow of the positive displacement pump at a certain speed or reciprocating times is certain, which hardly changes with the pressure; The flow and pressure of the reciprocating pump have large pulsations, so corresponding pulsation reduction measures need to be taken; Rotary pump generally has no pulsation or only small pulsation; With self-priming capacity, the pump can pump out the air in the pipeline and inhale liquid after starting; When starting the pump, the discharge pipeline valve must be fully opened; Reciprocating pump is suitable for high pressure and small flow; Rotary pump is suitable for small and medium flow and high pressure; Reciprocating pump is suitable for conveying clean liquid or gas-liquid mixture. In general, the efficiency of positive displacement pump is higher than that of power pump

powered pumps rely on the force of the rapidly rotating impeller on the liquid to transfer mechanical energy to the liquid, so that its kinetic energy and pressure energy are increased, and then through the pump cylinder, most of the kinetic energy is converted into pressure energy to realize transmission. Power pump is also called impeller pump or vane pump. Centrifugal pump is the most common power pump

there is a limit value for the head generated by the power pump at a certain speed, and the head changes with the flow; Stable operation, continuous transmission, no pulsation of flow and pressure; Generally, there is no self-priming capacity, so it is necessary to fill the pump with liquid or vacuum the pipeline before starting to work; Wide range of applicable performance; It is suitable for transporting clean liquids with low viscosity. The specially designed pump can transport mud, sewage, etc. or water transport solids. Power pumps are mainly used for water supply, drainage, irrigation, process liquid transportation, power station energy storage, hydraulic transmission and ship jet propulsion

one of the other types of plastic omnipotence pumps refers to a kind of pump that transfers energy in another way and strives to build brand products on key steel varieties such as construction bridge steel, automobile steel, household appliance steel, energy steel, machinery steel, shipbuilding and marine engineering steel, railway steel and so on. For example, the jet pump sucks the fluid to be transported into the pump by relying on the working fluid ejected at high speed, and transfers energy by mixing the two fluids for momentum exchange; The water hammer pump uses the energy generated when the flowing water is suddenly braked to raise part of the water pressure to a certain height; Electromagnetic pump is to make the electrified liquid metal flow under the action of electromagnetic force to realize transportation; The gas lift pump sends compressed air or other compressed gas to the bottom layer of the liquid through the pipe to form a lighter gas-liquid mixed fluid, and then uses the pressure of the liquid outside the pipe to lift the mixed fluid

the performance parameters of the pump mainly include flow and head, in addition to shaft power, speed and necessary cavitation allowance. Flow refers to the amount of liquid output through the pump outlet in unit time, generally using volume flow; Head is the energy increment of the liquid delivered per unit weight from the pump inlet to the outlet. For positive displacement pumps, the energy increment is mainly reflected in the increase of pressure energy, so it is usually expressed by pressure increment instead of head. The efficiency of the pump is not an independent performance parameter. It can be calculated by other performance parameters such as flow, head and shaft power according to the formula. On the contrary, given the flow, head and efficiency, the shaft power can also be calculated

there is a certain interdependent relationship between the performance parameters of the pump. Through the test of the pump, the parameter values can be measured and calculated respectively, and drawn into curves. These curves are called the characteristic curves of the pump. Each pump has a specific characteristic curve, which is provided by the pump manufacturer. Generally, the recommended performance range is also indicated on the characteristic curve given by the factory, which is called the working range of the pump

the actual working point of the pump is determined by the intersection of the pump curve and the pump device characteristic curve. When selecting and using the pump, the working point of the pump should be within the working range to ensure the economy and safety of operation. In addition, when the same pump delivers liquids with different viscosities, its characteristic curve will also change. Generally, the characteristic curve given by the pump manufacturer mostly refers to the characteristic curve when transporting clean cold water. For power pumps, with the increase of liquid viscosity, the head and efficiency decrease, and the shaft power increases. Therefore, in industry, sometimes the liquid with high viscosity is heated to reduce the viscosity, so as to improve the transmission efficiency

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