Submersible electric pump, as the name suggests, is a mechanical and electrical integrated submersible that works in the water. It has a simple structure and is convenient to use. With the development of electric motors, mechanical seals, and control technology, submersible electric pumps have developed rapidly.
1、 Overview of the Development of Submersible Electric Pumps Abroad
In 1928, the Bron Jackson Company in the United States first developed a submersible electric pump, which has been more than 60 years now. Subsequently, in the 1930s, German Plow Company, British Hayward Taylor Company, German KSB Company, Ritz Company, American B.J. Company, and Japanese Hitachi Company began producing deep well submersible pumps one after another.
Swedish Feili Company first successfully developed a submersible electric pump for drainage in 1948, and later established subsidiaries in 15 countries such as the Netherlands, Canada, the United States, and Germany. In 1956, submersible sewage pumps were produced, which reduced the cost of sewage pump stations by approximately half. Feili Company has designed innovative and diverse pump structures, and has developed four series of submersible pumps; 2000 series (for pumping corrosive liquids containing small particles), 3000 series (for pumping large flow sewage submersible pumps for civil and industrial wastewater), 5000 series (for pumping clean water), and 7000 series (for large flow medium head spiral pumps).
In the 1960s, the United States, the United Kingdom, Germany, Finland, Russia, and Japan (such as Nissan, Hiroshima, Sakuragawa, Ebara, etc.) also mass-produced submersible pumps for work surfaces. Japan's construction equipment and engineering submersible pumps have been standardized and serialized, achieving new achievements in structural design, material selection, and automatic control.
2、 Overview of the Development of Submersible Electric Pumps in China
China began producing NQ type agricultural deep well submersible pumps in the 1960s, and after improvement, they have developed to the current JQ type deep well submersible pump. At present, the maximum diameter can reach 500mm and the maximum lift can reach 500m. It is mainly used for agricultural irrigation and water supply and drainage in industrial and mining enterprises, with an annual production capacity of about 50000 units. The main manufacturers include Shijiazhuang Submersible Pump Factory, Jilin Water Pump Factory, Jiezhou Submersible Pump Factory, Zibo Submersible Motor Factory, Shenyang Water Pump Manufacturing Co., Ltd., and so on.
In 1958, Shanghai People's Electric Machinery Factory began producing 7KW submersible electric pumps for working surfaces in China. By the 1960s, it developed into QY type submersible electric pumps (with oil filled motors), with four specifications and flow rates of 15, 25, and 65100m, respectively ³/ H. By the 1970s, the QS series of small submersible electric pumps (filled with water in the motor) were developed, mainly used for agricultural drainage and irrigation. In the 1980s, dry motor QX and QDX (single-phase) small submersible pumps were developed. At present, the annual output of these small submersible pumps is about 1.5 million units, and their manufacturers mainly include Shanghai Renmin Electric Motor Factory, Hangzhou Water Pump General Factory, Taizhou Submersible Pump Factory, etc. In the late 1980s, domestic production of sewage submersible pumps began. The impeller forms include single blade, semi open, open multi blade, swirl, single channel, double channel, and spiral centrifugal, with an annual output of about 50000 units. The main manufacturers include Yangzhou Asia Pacific Special Water Pump Factory and Nanjing Shenjing Pump Factory. The Institute of Fluid Machinery at Jiangsu University of Technology collaborated with factories such as Yangzhou Asia Pacific Special Water Pump Factory to systematically study sewage submersible pumps. Three provincial and ministerial level scientific research projects were undertaken, and experimental research was conducted on the influence of flow state and geometric parameters inside the pump on pump characteristics. Thus, I have mastered the design methods of various non clogging sewage submersible pumps and accumulated rich experience in improving the performance of non clogging pumps.
Shenyang Water Pump Manufacturing Co., Ltd. is currently the largest manufacturer of submersible sewage pumps, submersible axial flow pumps, and submersible mixed flow pumps in China. Its products mainly have the following characteristics;
1. Complete variety and specifications;
2. Adopting dual channel impellers, it is not only anti clogging and anti winding, but also easy to balance, runs smoothly, and has high reliability.
3. The protection equipment is complete and internally equipped with: a thermal overload protector in the stator winding, a water inlet protector (electrode) in the oil chamber, and a water inlet protector (float) installed at the lower end of the motor cavity;
4. Provide complete sets of equipment such as automatic coupling installation and automatic control devices.
3、 Development Trends of Submersible Electric Pumps
The submersible electric pump on the working surface is an electromechanical integrated product with a simple and compact structure, easy to use, and the demand will continue to grow, with the following development trends;
1. Develop large and medium-sized submersible electric pumps
Large and medium-sized submersible electric pumps have outstanding advantages of simplifying pump structure and saving investment in pump station construction. They have been used in municipal, industrial, mining, enterprise, and agricultural water supply and drainage, and are expected to increase significantly in the future.
2. Develop various forms and uses of submersible electric pumps
There are not many forms of submersible pumps in China compared to the pumps of Sweden's Feili Company, such as pumps with cutting devices, multi-stage pumps, and submersible pumps for pumping corrosive media, which are rarely produced.
3. Develop high reliability mechanical seals
Mechanical sealing is the key to submersible electric pumps. Two single end mechanical seals are used, so that the pressure of the medium can act on the end face and the leakage direction is an internal flow pattern. These are beneficial, but the structure is slightly complex. Install double ended mechanical seals in the oil chamber, and the end faces on both sides should adopt different structural forms, so that the pressure of the medium can act on the lower end face, otherwise only relying on spring force. The reverse thrust of the sealing end face easily causes the end face to open. Further research should be conducted on the structure and materials to improve their reliability and lifespan.
4. Adopting new materials
Ordinary pumps have already used stainless steel, fluoroplastic (F46), high-density polyethylene, plastic lining, rubber lining, ceramic spraying, etc. All these materials should be applied to submersible pumps as soon as possible to change the current situation where only cast iron is used as the material for submersible pumps, and expand the application field of submersible pumps.
5. Pay attention to appearance quality
Some submersible pumps in China have good appearance quality, while others are not good enough, such as surface painting and roughness, which need further improvement to enable domestic submersible pumps to enter the international market more.
