Tiếng Việt
RESEARCH AND DEVELOPMENT OF A SINGLE-STAGE, DOUBLE-SUCTION CENTRIFUGAL PUMP WITH HEAD UP TO 200M FOR MINING DEWATERING AND MOUNTAINOUS WATER SUPPLY
Nguyen Duc Cach¹, Dang Quang Hao²
¹Engineer, Hai Duong Pump Manufacturing Joint Stock Company (HAPUMA), Hai Duong, Vietnam
²Master of Science, Hai Duong Pump Manufacturing Joint Stock Company (HAPUMA), Hai Duong, Vietnam
Corresponding author:
Eng. Nguyen Duc Cach
Hai Duong Pump Manufacturing Joint Stock Company (HAPUMA)
No. 2 Ngo Quyen Street, Hai Duong City, Vietnam
Abstract
In the mining industry, open-pit mine dewatering operations commonly use floating single-stage, double-suction centrifugal pumps with large flow rates and high heads. These pumps are characterized by high efficiency, compact design, easy assembly and maintenance and stable operation. Globally, most major pump manufacturers produce standard series of such pumps with heads up to approximately 160 meters. However, single-stage, double-suction centrifugal pumps with heads of 200 meters or higher are only developed by a few leading manufacturers due to complex requirements in hydraulic design, mechanical construction and material technology. As a result, Vietnam has long depended on imported high-head pumps.
The successful implementation of the project titled “Research, Design and Manufacture of a Single-Stage, Double-Suction, High-Head Centrifugal Pump with a Head of up to 200m” by Hai Duong Pump Manufacturing Joint Stock Company (HAPUMA) has met the urgent domestic demand in the mining industry, reduced reliance on imports and opened opportunities for optimized water supply solutions for highland regions—supporting both household and agricultural needs.
Keywords: centrifugal pump, double-suction pump, high-head pump
1. INTRODUCTION
In the mining and mineral processing industry, whether underground or open-pit mining, dewatering is an essential part of production. Due to the specific characteristics of installation terrain, the types of pumps used for these operations are usually single-stage double-suction centrifugal pumps or multistage centrifugal pumps.
In open-pit mining, increasing mining depths and expanding operational scales—alongside climate change and rising rainfall—have created a pressing need for large-flow, high-head dewatering systems to maintain productivity.
While multistage centrifugal pumps can achieve high heads, they typically have small flow rates, complex structures and are difficult to assemble and maintain. Therefore, they are less suitable for open-pit dewatering and are more often used in underground mining operations.
A single-stage double-suction centrifugal pump essentially combines two single-suction impellers in parallel to increase flow capacity. This configuration allows for very large flow rates (up to 10,000 m³/h) and offers axial thrust self-balancing, high efficiency and excellent suction performance. Particularly, the between-bearing, horizontally split casing design provides easy disassembly for maintenance and ensures stability and durability in harsh working environments—such as floating platforms or uneven terrain—making it ideal for open-pit mine drainage applications.
In recent years, several major Vietnamese coal mining companies—such as Coc Sau Coal JSC, Cao Son Coal JSC and Duong Huy Coal Company—have used double-suction centrifugal pumps with flow rates of about 1,000 m³/h and heads up to 200 meters for open-pit dewatering.
However, pumps of this specification are rarely produced worldwide due to the special requirements in hydraulic design, mechanical structure and material technology. Imported pumps, mostly from China, often suffer from inconsistent quality, unreliable spare part availability and unstable operation. High-quality pumps from global manufacturers such as Flowserve, Sulzer and Andritz are available, but they come with very high costs, long delivery times and limited spare part supply.
Therefore, developing and successfully manufacturing such a pump domestically—at a competitive cost—provides significant advantages: ensuring self-reliance in production, reducing mining costs and meeting the growing demands of the mineral industry.
Beyond mining applications, the Government’s policy of promoting agricultural development and improving living standards in highland regions has also created growing demand for large-flow, high-head water supply systems. For example, the Le Hong Phong Revolutionary Base water supply project in Binh Thuan Province pumps water from the Luy River to an elevation of nearly 200 meters. Similarly, water supply and irrigation systems for industrial crops (such as coffee and pepper) in the Central Highlands require pumps with large flow and high head capacities. The use of such pumps helps reduce construction and operational costs by minimizing the need for intermediate pumping stations.
As a company specializing in the design and manufacture of industrial pumps serving both public and industrial sectors across Vietnam, HAPUMA recognized these practical needs and, leveraging its capabilities, proposed and successfully implemented the project titled:
“Research, Design and Manufacture of a Single-Stage, Double-Suction, High-Head Centrifugal Pump with a Head of up to 200m for Mine Drainage.”
This project contributes to the National Key Science and Technology Program for the Renewal and Modernization of Mining and Mineral Processing Technologies to 2025, approved by the Minister of Science and Technology and addresses both domestic industrial demands and future export opportunities to regional markets.
2. RESEARCH METHODS
The double-suction centrifugal pump has been researched, designed and manufactured as a standardized product series by Hai Duong Pump Manufacturing Joint Stock Company (HAPUMA), with a head of up to 150 meters. Owing to its advantages, this type of pump has been increasingly applied in various sectors such as mine drainage, water supply for clean water production and water supply for highland areas, among others.
However, since this type of pump is a single-stage design, it is limited in head capacity. Pumps with flow rates up to 1,000 m³/h and heads up to 200 m typically exhibit the following characteristics: very low specific speed (<40), narrow impeller width, large impeller diameter and consequently low hydraulic efficiency due to high flow friction losses within the impeller passages. Additionally, these pumps are difficult to manufacture by casting and require impeller materials with high mechanical strength to withstand large peripheral velocities.
To develop pumps with high efficiency and superior quality, the research team employed a comprehensive research methodology that combined traditional hydraulic and structural design approaches with advanced computational tools. Specialized design software was used to simulate and optimize the hydraulic profiles. Furthermore, the team conducted research on casting technology using austenitic and duplex stainless steels, as well as precision machining techniques to ensure high-pressure resistance at critical assembly joints.
2.1. Hydraulic Profile Design
The hydraulic design was carried out using the specialized software Concept NREC (USA). This software enables preliminary hydraulic design, followed by iterative optimization and flow simulation. Based on the velocity and pressure fields within the impeller and volute casing, the research team optimized the profiles until the highest efficiency was achieved.
A model pump was then designed, manufactured and tested for performance evaluation before proceeding to fabricate the full-scale prototype. The prototype was also tested to ensure that the obtained parameters of flow rate (Q), head (H) and efficiency met the optimal design requirements. Only after achieving results comparable to those of equivalent pumps from advanced industrial nations was the pump approved for official production and commercial manufacturing.
Figure 1. Simulation of pressure and velocity fields for hydraulic profile optimization
2.2. Structural Design Ensuring High Strength and Stable Operation
The research team adopted a comparative design approach by studying high-head double-suction pump structures from leading global manufacturers such as Flowserve, Sulzer and Andritz. In addition, on-site surveys were conducted at open-pit mining sites and petrochemical plants to analyze the practical operating conditions.
Through a detailed analysis of the advantages and disadvantages of various design solutions — including bearing housings, sealing chambers and impeller configurations — the team selected a structural layout suitable for HAPUMA’s existing technological capabilities while ensuring operational stability under harsh conditions, such as floating installations and exposure to corrosion and abrasion.
During the structural design process, calculations were performed to select bearings meeting required service life, ensure dynamic balance according to ISO 1940 standards and verify shaft strength and stability. These efforts resulted in a pump structure that optimally satisfies both manufacturing capability and technical performance requirements.
Given that the pump was designed to achieve heads up to 200 meters, the impeller diameter reached 780 mm. At an operating speed of 1,450 rpm, the centrifugal forces acting on the impeller shrouds and blades were extremely large, potentially leading to cracking or tearing during operation. To enhance the mechanical integrity of the rotating assembly, the research team designed the impeller blades in a staggered arrangement on both sides and incorporated intermediate (split) blades, effectively increasing the impeller’s mechanical strength.
2.3. Materials and Manufacturing Technology
In addition to the unique impeller design that improves mechanical durability compared to conventional pumps, the research team combined theoretical calculations with empirical experience to select materials offering both sufficient mechanical strength and resistance to chemical corrosion — particularly suitable for the acidic mine-water environment found in Quang Ninh coal mines.
For clean-water applications, impellers and casings can be manufactured from ductile cast iron or single-phase austenitic stainless steels (SCS13, SCS14A). For highly acidic water conditions, such as those encountered in certain coal mines in Quang Ninh, duplex stainless steel was chosen for the impeller. This material offers both high mechanical properties and excellent chemical corrosion resistance, ensuring the long-term durability of the pump.
All selected materials have been smelted and produced by Hai Duong Pump Manufacturing Joint Stock Company (HAPUMA) to international standards for many years. However, given the specific characteristics of a narrow outlet width and large impeller diameter, the casting process required particular attention. To achieve smooth, defect-free castings, the team combined theoretical analysis, casting simulation using Cast Designer software and extensive practical experience accumulated over multiple casting trials.
This successful optimization of the casting process represents a key technological breakthrough in manufacturing high-head double-suction centrifugal pumps.
Figure 2. 3D design drawing for casting technology (input data for simulation)
Figure 3. Simulation and optimization of the casting process
The machining and assembly stages were given particular attention to precision grade and rotor balancing accuracy. These processes were carried out using the Company’s available CNC machining systems and dynamic balancing machines to ensure optimal performance and stability.
Figure 4. CNC machining of the pump casing
2.4. Testing and Quality Evaluation
As with other pump types manufactured by HAPUMA, all performance parameters of the product were thoroughly tested prior to delivery. The hydraulic characteristics of the pump were evaluated on HAPUMA’s advanced test system, ensuring that both testing procedures and reliability fully complied with ISO 9906:2012 standards.
Figures 5 and 6 illustrate the testing process and performance results of the LHP1000-200 pump at HAPUMA’s Testing Center.
Hình 5: Quá trình thử nghiệm |
Hình 6: Đặc tính kỹ thuật của bơm LHP1000-200 |
After meeting all technical specifications during laboratory testing, the pump was further evaluated under actual operating conditions. Field tests confirmed its vibration stability, low noise levels, reliable continuous performance and most importantly its excellent resistance to highly corrosive environments.
Figure 7. The pump installed at the open-pit mining site of Cọc Sáu Coal Joint Stock Company – Quảng Ninh Province
3. RESULTS AND ACHIEVEMENTS
The single-stage, double-suction centrifugal pump with a head of up to 200 meters (model LHP1000-200) was successfully designed, manufactured and tested for the first time in Vietnam. The Hai Duong Pump Manufacturing Joint Stock Company (HAPUMA) has since produced this model in series and commercialized it, supplying to units such as Cọc Sáu Coal JSC, Cao Sơn Coal JSC and Dương Huy Coal JSC, effectively replacing imported pumps from China.
The success of this project not only resulted in a high-performance, domestically produced product that meets the demanding requirements of the mining industry but also demonstrates Vietnam’s growing capability in independent research, design and manufacturing of high-quality industrial pumps.
Moreover, the single-stage, double-suction centrifugal pump with a head of up to 200 meters has proven to be highly effective in clean water production, agricultural irrigation systems and water supply for highland and remote areas, contributing to both industrial development and community welfare.
This study was published on the official website of the Journal of Mechanics and Life (Vietnam).
Source: https://ckds.vn/cong-nghe/nghien-cuu–thiet-ke–che-tao-thanh-cong-may-bom-ly-tam-mot-cap–hut-hai-phia–cot-ap-cao—-2118