Abstract: Submersible pump is a pump and motor combination of a special delivery of liquid machinery, as its name implies, the integration of mechanical and electrical work in the water. It is simple in structure and easy to use. Submersible pumps have been developed rapidly with the development of materials science, sealing technology, control and protection technology, and the improvement of hot and cold processing technology.
THE TYPICAL STRUCTURE ANALYSIS AND ENGINEERING
APPLICATION OF SUBMERSIBLE PUMPS
Shi Weidong
(Jiangsu University of Science and Technology, Zhengjiang, 212013)
ABSTRACT The author reviews the development general situation and analysis the typical structure of submersible pump at home and abroad, introduces the structure shapes of impeller.types and engineering application at abroad. It is characterized by a great variety and in a novel design.it can be used for reference at home.
KEY WORDS submersible pump, general situation, impeller structure analysis application
introduction
Submersible pump is a pump and motor combined into a special liquid-conveying machinery, as the name implies, the integration of mechanical and electrical work in the water. It is simple in structure and easy to use. Submersible pumps have been developed rapidly with the development of materials science, sealing technology, control and protection technology, and the improvement of hot and cold processing technology.
In 1904, the Byron Jackson Company of the United States successfully designed and manufactured horizontally connected submersible pumps and submersible motors, which is the "ancestors" of modern submersible pumps. In 1928, the company invented a direct-connected vertical submersible pump, the original form of a modern deep submersible pump. Can be seen that the development of submersible pumps have been more than 60 years of history.
Sterbery Flygt, a Swedish company, successfully developed the world's first shallow water (or work surface) submersible pump for water supply and drainage in 1948, radically simplifying the type of pump and reforming the foundation pit And mine drainage equipment, and soon to be successful around the world. In 1956, Flygt produced a submersible pump for sewage discharge, reducing the cost of pumping stations by about half. In addition, Flygt company has solved a series of difficult problems, developed a variety of special submersible pumps can be used to suck abrasive fluid containing solid particles, viscous solution and corrosive liquids. In recent years, Flygt has made great strides in pump construction and has developed four series: the 2000 Series pumping small particles of abrasive fluid, the 3000 series of large flow sewage submersible pumps for pumping civil and industrial wastewater, pumping clear water 5000 series, with a large flow of medium lift helical (axial flow) of the 7000 series.
By the 1960s, the United States, Britain, Germany, France, Finland, Japan and other countries also mass-produced operating submersible pump. In particular, Japan (such as Hitachi and Tsurumi) has achieved the standardization and serialization of submersible pumps for construction equipment and engineering and has achieved new successes in structural design, materials selection and automatic control.
In 1958, Shanghai People's Electric Machinery Factory began to produce 7kW submerged electric pump in operation area, which opened the prelude to the production of submersible pump in our country. After more than 30 years of development, we have made great achievements. Has produced a QY, QS, QX, QDX (single-phase) series of small submersible pumps. Annual output of about 1.5 million units. Since the late 1980s has developed a QW sewage submersible pump. QZ submersible axial flow pump and QH submersible mixed flow pump. Annual output of about 80,000 units. Institute of Fluid Machinery, Jiangsu University of Technology and the Asia-Pacific special Yangzhou Pump Factory and other plants, a systematic study of the sewage submersible pump, has assumed three provincial and ministerial level scientific research projects. Experimental study of the pump flow state, leaf structure types, geometric parameters of the pump characteristics and so on. Thus grasping a variety of non-clogging sewage submersible pump design theory and methods, to improve the performance of non-clogging pump has accumulated rich experience and has won four national and provincial and ministerial level scientific and technological progress awards, but also by the state Science and Technology Commission as a national key scientific and technological achievements promotion project.
A typical structure analysis of submersible pump at home and abroad
1.1 foreign submersible pump typical structure analysis
Flygt Corporation is the world's largest manufacturer of submersible pumps, with the most complete range of submersible pumps. Its new product design, component system standardization, equipment modernization. Now choose one of the typical structure to be analyzed.
Flygt company's typical C pump structure, the main features are as follows.
(1) The motor cable must be able to withstand media erosion, the cable can be flexible metal hose protection.
(2) Stator insulation class F (155 ℃). According to the standard, the motor stator is loaded with overload protector.
(3) When the power is above 9kW, the cooling system is installed. The back vane of the impeller circulates the cooling water around the stator chamber. Can also use an independent cooling system, the outer cooling jacket and volute are not the same, the introduction of cooling water directly from the outside. This type of cooling system is particularly effective when the temperature of the pumped liquid can increase or is likely to dry.
(4) A double mechanical seal between the motor and hydraulic components to prevent liquid from entering the motor chamber. The upper layers are usually graphite / tungsten carbide, lower tungsten carbide / tungsten carbide. In addition to the tungsten carbide, the sealing material may also be alumina or silicon carbide.
(5) According to different uses, different impeller structure type. The illustrated impeller has a large passage area and can reduce the risk of blockage by means of large particles and wrappings.
(6) A replaceable seal ring is placed between the pump impeller and pump body to keep the pump running at optimum efficiency. Large pumps have two sets of seal rings.
1.2 Domestic submersible pump typical structure analysis
Yangzhou Asia-Pacific Special Pump Factory is currently the largest domestic manufacturer of submersible pumps, and its products have been successfully applied to large-scale key national projects such as Shanghai Baosteel, Daqing Oilfield and Beijing New Passenger Station, replacing a large number of imported products. At the same time, its development products have entered the international market.
Designed by Institute of Fluid Machinery of Jiangsu University of Science and Technology, the typical structure of QW sewage submersible pump produced by Yangzhou Asia-Pacific Special Pump Factory is as follows.
(1) Submersible pumps with power above 30kW. Wiring cavity with water detection probe, when the cable is broken or other reasons, the probe sends a signal, the control system to protect the pump.
(2) The stator of the motor adopts Class F insulation (155 ℃) and is designed as a thin and long cylinder with over-temperature protection.
(3) When the power is above 15kW, each pump is equipped with its own cooling system. The back vane of the impeller circulates the water in the vortex chamber to the outer periphery of the stator chamber to circulate and cool, which can ensure that the pump is normal under the minimum water level in the pool or drained Run.
(4) The lower end of the motor chamber is equipped with water leak detector? Float switch, when the water enters the motor chamber signal, the control system to pump protection.
(5) Between the motor and hydraulic components with a double mechanical seal to prevent leakage of medium into the oil chamber, the upper and lower scientific matching can ensure the safe and reliable pump operation. Sealing materials are silicon carbide, tungsten carbide, carbide or super wear-resistant seal vice.
(6) The oil chamber is equipped with electrode protection. When the water enters the oil chamber, the electrode sends out a signal which is displayed by the control system to inform the management staff timely maintenance. At the same time, the control system closely monitors its leakage.
(7) The unique design of the impeller, with a large channel, through the large materials and fibers, to reduce the risk of clogging, winding.
(8) A replaceable seal ring is placed between the pump impeller and volute to keep the pump running at optimum efficiency.
2 foreign submersible pump types and engineering applications
With the continuous development of science and technology, there are quite a few new types and structures of submersible pumps in foreign countries. This article only takes the submersible pump produced by Flygt as an example. Its wide variety, innovative design, the reference for domestic counterparts.
Table 1 Flygt submersible pump types and engineering applications
name
Impeller Structure Type Impeller Structure Characteristics Engineering Application
B Pump open or semi-open impeller, anti-wear materials, with adjustable guide vanes and filters are widely used in construction sites, caves, harbors, factories, ships and other water supply and drainage or water jet, etc. can be pumped Abrasives such as clay, sand, gravel, drill cuttings and other liquid media.
Mobile structure, put in the water can start, to meet the large flow, high lift, limited space or explosive environment and other special requirements.
C pump plug-in closed-flow impeller, with good reliability and high efficiency.
It is mainly used for pumping sewage and mud in urban pumping stations and sewage treatment plants, pumping cooling water, waste water and corrosive media in industrial processes, and continuously discharging water on sites and large factories. Ideal for pumping media containing long fibers and large solids.
Installed in a small and simple pump station, hidden underground, the pump can be quickly and easily mounted on rails or ropes and down to the pump pit.
D-pump swirling impellers are widely used in construction, mining, industrial pumping of wastewater containing long fibers, clays, cuttings, rock fragments, sludge and aggressive media, and to meet the requirements of drainage in explosive atmospheres.
F pump impeller with S-type shut-off, with pumping, cutting and mixing functions. Good reliability, high efficiency.
It is mainly used to pump liquid manure in agriculture, to crush dry solids, straw and other long fiber materials. The helical impeller inlet can pump aspirated thick manure into the pump for a total of four specifications.
Compact structure, installed in the manure tank in the rail, can also be installed in the storage pool, can be used in conjunction with the submersible mixer.
G pump open or closed impeller, a number of blades are mainly used in the basement or other areas of the ground drainage, can also be used for irrigation, to meet the needs of small flow and moderate lift, suitable for pumping water or slightly polluted water, a total of three Specs
Compact structure, easy to install, just put the pump on the bottom of the pit can be.
H pump
Open or closed flow impeller, anti-wear material manufacturing is mainly used for mining, construction sites, caves, tunnels and dams and other places pumping fluid containing abrasive particles such as drill cuttings, sand, gravel, suction side with adjustable The rubber coating helps to run at efficient points.
L pump closed-flow impeller, and guide vane match, good reliability.
Widely used in city, agriculture, ships, industrial and other water supply and drainage, to meet the needs of low-lift high-flow, flow up to 2000m3 / h, suitable for pumping water or slightly polluted water, a total of six specifications.
Installation, maintenance is simple, with no pipeline connection design.
M Pump impeller with a chopper at the entrance, made of chrome alloy and stainless steel, especially suitable for pressurized sewer systems that can be transported by means of a pipe of only 40 mm diameter.
P pump adjustable blade axial impeller, with high efficiency and energy saving features.
Mainly used for agriculture, urban water supply and drainage and industrial cooling water, etc., and can be used to control inland waterway system. To meet the special needs of low-lift large flow, suitable for pumping water or slightly polluted water.
The structure is compact and simple, does not require special installation, just drop to the shoulders of the shell seat can be.
R Pumps Multi-bladed closed impeller, cast in cast iron or stainless steel, water on one or both sides (double suction).
Particularly suitable for agricultural irrigation and a variety of industrial applications, such as for water, process water, jet and cooling water. To meet the needs of high-lift large flow, flow up to 2000m3 / h, head up to 110m, suitable for pumping water or slightly polluted water, a variety of specifications and structure type.
Powerful, reliable, easy to install and maintain.
3 Conclusion
Submersible pump in China after 30 years of development, has made considerable achievements. However, compared with the advanced countries in the world today, there is still a long way to go. The product variety is still not enough, its fields of application are also narrow, and its reliability and quality are not stable enough. These are yet to be further improved, As soon as possible pump into the international market, and gradually replace the introduction of products. It is foreseeable that with the continuous development of the socialist market economy, our own submersible pump will play an increasingly greater role in various sectors of industrial and agricultural production and the national economy such as mechanical and electrical drainage, urban drainage and environmental protection.
About the author: Shi Weidong, male, born in February 1964, graduated from Jiangsu Polytechnic University in 1984 with a bachelor's degree in hydraulics, currently an associate researcher at Jiangsu Polytechnic University.
Author: Shi Weidong (Jiangsu University of Science and Technology, Zhenjiang, 212013)
references
1 off all compiled. Modern Pump Technology Handbook. Beijing: Aerospace Press, 1995
2 Yuan Shou its. History and Development Trend of Small Submersible Pump. Irrigation and drainage machinery, 1994 (1): 3 ~ 10
3 Shi Weidong edited. Fluid Machinery. Chengdu: Southwest Jiaotong University Press, 1996
4 Shi Weidong, off wake up where. Submarine Pump Control System Overview. Journal of Agricultural Machinery, 1996 (4): 126 ~ 129 Â
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