One, what is the pump?
Pump is conveying liquid or causes the liquid turbo-charged machinery.It transmits the mechanical energy or other external energy transmitted to the liquid, causes the liquid energy increase.
Pumps are mainly used for conveying water, oil, the sour lye, the emulsion, hangs the emulsion and the liquid metal, such as liquid, also may transport the liquid, the mixture of gas and liquid containing suspended solids.
Pumps usually according to the principle of work is divided into positive displacement pump, the power type pumps and other types of pumps.In addition to according to the principle of work classification, but also can be classified and named by other methods.Such as, according to the driving method can be divided into electric pump and turbine pump, etc.;According to the structure can be divided into single-stage and multistage pump;According to the purpose can be divided into the boiler feed water pump and the metering pump, etc.;According to the nature of the liquid can be divided into oil pump, water pump and mud pump, etc.
Each pump performance parameters between the certain relation between depend on each other, and can be expressed in the curve, known as the pump characteristic curve of each pump has its own specific characteristic curve.
Two, the definition and history of pump source
Conveying liquid or causes the liquid turbo-charged machinery.Pump is conveying fluid or make it in the broadest sense of the turbo machinery, including certain mechanical conveying gases.The pump the prime mover’s mechanical energy or other energy sources of energy to the liquid, causes the liquid energy increase.
The ascension of water is very important for human life and production.Ancient for various water apparatus, such as Egypt’s chain pump (17th century), China’s shadoof (17th century), jigger (11th century), the water wheel (the 1st century AD), as well as the invention of the third century BC in ancient Greece Archimedes screw, etc.Around 200 BC, the ancient Greek artisans Kurt west than uz invented the most primitive piston pump – fire pump.As early as 1588 with about 4 blade vane pump, later emerged in succession various rotary pump.D. in 1689, the French President of the pan invented 4 volute centrifugal pump impeller blades.In 1818, the United States appeared with radial straight blade, half open double suction impeller and volute centrifugal pump.1840 ~ 1840, the United States of H.R. worthington invented the pump cylinder and steam cylinder piston pump, the role of the steam of buy direct marks the formation of modern piston pump.From 1851 to 1875, multistage centrifugal pump with guide vane invention, make it possible to develop high lift centrifugal pump.Subsequently, a variety of pump field.With the application of all kinds of advanced technology, the efficiency of the pump gradually increase, performance and application are also growing.
Three, the classification of the pump
There are many types of pumps, according to the principle of work can be divided into:
(1)power pump, also called impeller pump or pump blades, rely on the dynamic function of rotating impeller for liquid, convey energy continuously to liquid, can make the liquid kinetic energy (mainly) and pressure increase, then through the pressure out of the room can converts kinetic energy into pressure, can divide again for centrifugal pump, axial flow pump, partial emission pump and vortex pump, etc.
(2)positive displacement pump, rely on containing liquid sealing work space volume of periodic change, convey energy periodically to liquid, will increase the pressure of the liquid to liquid forcibly from, according to the working components form of exercise and can be divided into reciprocating pump and rotary pump.
(3)other types of pumps, the transfer of energy by any other means.Such as the jet pump on the working fluid of high speed jet will take after the suction pump of the fluid mix, momentum exchange to transmit energy;Water hammer pump using brake parts of the flow of water was up to a certain height transfer energy;Electromagnetic pump is to make the electricity liquid metal under the action of electromagnetic force to produce flow and transport.In addition, the pump may also be driven by conveying the nature of the liquid, method, structure, purpose, etc.
Four, pump application in all fields
From the scope of the performance of the pump, giant pump flow rate can reach more than hundreds of thousands of cubic meters per hour, and the micro pump flow per hour in a few ml of the following;The pressure of the pump can be up to 19.61 Mpa from atmospheric pressure to (more than 200 KGF/cm2);The lowest temperature of the liquid to be delivered – below 200 degrees Celsius, the highest can reach more than 800 degrees Celsius.Type of liquid pump is various, such as water (water, sewage, etc.), oil, acid alkali, suspension, and the liquid metal, etc.
In the department of chemical and oil production, raw materials, semi-finished products and finished products are liquid, and the raw material, semi-finished products and finished products need to go through complex processes, pumping play in these processes for conveying liquid and provide the role of the pressure of the chemical reaction flow, in addition, also used in many gear pump to adjust temperature.
In the agricultural production, pump is the main drainage and irrigation machinery.The original extensive in rural areas in China, the countryside every year need a lot of pump, general agricultural pump more than half of the total pump production.
In the mining and metallurgical industry, pump is the most used equipment.Mine need pump drainage, in mineral processing, smelting and rolling process, the need to pump water first, etc.
In the electricity sector, nuclear power plants need nuclear main pump and secondary pump, pump, thermal power plant requires a lot of boiler feed water pumps, condensate pumps, circulating pumps and ash pump, etc.