Submersible electric pump, as the name suggests, is an integrated mechanical and electrical device that operates underwater. It has a simple structure and is easy to use. With the development of motors, mechanical seals, and control technology, submersible electric pumps have experienced rapid growth.

1、 Development Overview of Submersible Electric Pumps Abroad

In 1928, the American Bloom Jackson Company first developed a submersible electric pump, and it has been over 60 years since then. Subsequently, in the 1930s, German companies such as Prolo, British company Hayward Taylor, German company KSB, Ritz, American company B.J., and Japanese company Hitachi successively began producing deep well submersible pumps.

Swedish company Feili successfully developed a submersible electric pump for drainage work surfaces in 1948, and later established subsidiaries in 15 countries including the Netherlands, Canada, the United States, and Germany. The production of submersible sewage pumps in 1956 reduced the cost of sewage pumping stations by approximately half. Feili Company’s pump designs are innovative and come in various structural forms, and has developed four series of submersible pumps; 2000 series (pumping corrosive liquids containing small particles), 3000 series (pumping high flow sewage submersible pumps for civil and industrial wastewater), 5000 series (pumping clean water), 7000 series (high flow medium head spiral type).

In the 1960s, the United States, Britain, Germany, Finland, Russia, Japan (Nissan, Tsurumi, Sakuragawa, Ebara, etc.) also produced large quantities of submersible electric pumps for working surfaces. Japan’s submersible electric pumps for construction equipment and engineering 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, it has developed into 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. The annual production capacity is about 50000 units. The main manufacturers include Shijiazhuang Submersible Pump Factory, Jilin Water Pump Factory, Jiezhou Submersible Electric Pump Factory, Zibo Submersible Motor Factory, Shenyang Water Pump Manufacturing Co., Ltd.

In 1958, Shanghai People’s Electric Machinery Factory began producing 7KW submersible electric pumps for working surfaces in China. In the 1960s, it developed into QY submersible electric pumps (with oil filled motors), with four specifications and flow rates of 15, 25, and 65100m ³/h. In the 1970s, the QS series of small submersible electric pumps (with electric motors filled with water) were developed, mainly used for agricultural irrigation and drainage. In the 1980s, dry motor QX and QDX (single-phase) small submersible electric pumps were developed. At present, the annual output of these small submersible electric pumps is about 1.5 million units, and their manufacturers mainly include Shanghai People’s Electric Machinery Factory, Hangzhou Pump Factory, Taizhou Submersible Electric Pump Factory, etc. In the late 1980s, domestic production of sewage submersible electric pumps began, with impeller forms including single blade, semi open, open multi blade, swirl, single channel, double channel, and spiral centrifugal. The annual output is about 50000 units, and the main manufacturers include Yangzhou Asia Pacific Special Pump Factory and Nanjing Shenjing Pump Factory. The Fluid Machinery Research Institute of Jiangsu University of Technology has collaborated with factories such as Yangzhou Asia Pacific Special Water Pump Factory to systematically study sewage submersible electric pumps. They have undertaken three provincial and ministerial level scientific research projects, conducting experimental research on the flow state inside the pump and the influence of geometric parameters on pump characteristics. Thus, I have mastered various design methods for non clogging sewage submersible electric pumps and accumulated rich experience in improving the performance of non clogging pumps.

Shenyang 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 a dual channel impeller, it is resistant to blockage and entanglement, easy to balance, runs smoothly, and has high reliability.

3. The protective equipment is complete and equipped with: thermal overload protector in the stator winding, water inlet protector (electrode) in the oil chamber, water inlet protector (float) installed at the lower end of the motor chamber, etc;

4. Provide complete sets of equipment such as automatic coupling installation and automatic control devices.

3、 Development trend of submersible electric pumps

Submersible electric pumps for work surfaces are electromechanical integrated products with simple and compact structures, easy to use, and 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 in simplifying pump structures and saving investment in pump station construction. They have been used in municipal, industrial and 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

Compared with the pumps of Sweden’s Feili company, there are not enough forms of submersible electric pumps in China, such as pumps with cutting devices, multi-stage pumps, and submersible electric pumps for pumping corrosive media, which are rarely produced.

3. Develop high reliability mechanical seals

Mechanical seal 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 internal flow. These are advantageous, but the structure is slightly more complex. Install dual end mechanical seals in the oil chamber, and the end faces on both sides should adopt different structural forms to allow the pressure of the medium to act on the lower end face, otherwise only relying on spring force. The reverse thrust of the sealed end face can easily cause 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 materials such as stainless steel, fluoroplastic (F46), high-density polyethylene, plastic lining, rubber lining, and sprayed ceramics. All of these materials should be applied to submersible electric pumps as soon as possible to change the current situation where only cast iron is used as the material for submersible electric pumps and expand the application field of submersible electric pumps.

5. Pay attention to the appearance quality

The appearance quality of submersible electric pumps in our country is relatively good in terms of design, while others are not good enough, such as surface painting and roughness, which are not emphasized. These need further improvement to enable domestic submersible electric pumps to enter the international market more.