Many core processes in mining sites (such as high-pressure spray dust suppression, hydraulic support driving, ore pulp transportation, and high-pressure water injection into coal seams) have high requirements for pressure. The structural characteristics of plunger pumps endow them with an inherent "high-pressure advantage":
Plunger pumps directly compress the medium through the reciprocating movement of the plunger in the cylinder block, without the "centrifugal force pressure limit" of centrifugal pumps (e.g., centrifugal pumps). Their rated working pressure generally reaches 10-50MPa, and some high-pressure models even exceed 100MPa. This enables them to easily meet the mining site's needs for "high-pressure penetration" (such as water injection crushing of coal seams) and "high-pressure transportation" (such as long-distance transportation of high-concentration ore pulp).
Compared with gear pumps, vane pumps, etc., plunger pumps have much smaller pressure fluctuations (usually ≤ ±1%). This can avoid problems such as insufficient supporting force of hydraulic supports and reduced spray dust suppression effect caused by sudden pressure drops, thus ensuring operational safety (e.g., preventing roof collapse).
Operating media in mining sites (such as ore pulp, coal-containing wastewater, and underground sewage) generally contain a large number of solid particles (such as coal cinders, ore debris) and corrosive components (such as sulfides, acidic substances). Ordinary pumps (e.g., centrifugal pumps) are prone to frequent failures due to "media wear" and "corrosion-induced jamming", while plunger pumps have significantly better anti-pollution capability:
The fit clearance between the plunger and the cylinder block is extremely small (usually 0.005-0.01mm), and their surfaces are mostly subjected to hardening treatment (such as chrome plating, nitriding, ceramic coating), with a hardness of over HRC60, which can resist the scouring and wear caused by solid particles. Meanwhile, the inlet and outlet valve groups of plunger pumps adopt a "check valve structure", which is not easily jammed by particles, reducing the risk of pump blockage.
Whether it is high-concentration ore pulp (solid content ≤ 30%), hydraulic oil containing impurities, or weakly corrosive underground wastewater, plunger pumps can be adapted by replacing sealing materials (such as fluororubber, polytetrafluoroethylene), without the need for additional installation of complex pre-treatment filtration systems, thus reducing system complexity.
Mining sites are high-energy-consumption scenarios, where the energy consumption of pump equipment can account for 20%-30% of the total energy consumption. The high volumetric efficiency of plunger pumps can directly reduce energy waste:
The volumetric efficiency of plunger pumps is generally between 90%-98% (far higher than 70%-85% of centrifugal pumps and 80%-90% of gear pumps). This means that most of the energy from the input motor is converted into "medium transportation work" rather than being lost due to leakage or backflow. Taking a 50kW plunger pump as an example, compared with a centrifugal pump of the same flow rate, it can save approximately 10,000-20,000 yuan in electricity fees annually (calculated based on 3,000 operating hours per year and an electricity price of 0.6 yuan per kilowatt-hour).
Some mining plunger pumps are equipped with variable displacement mechanisms (such as electric control variable displacement and hydraulic control variable displacement), which can adjust the flow rate in real time according to operational needs (e.g., lifting speed of hydraulic supports, spray volume), avoiding energy waste caused by "using a large motor for a small load". For instance, during coal seam water injection, the flow rate can be dynamically reduced according to the coal seam permeability to further reduce energy consumption.
Mining operations mostly run continuously 24 hours a day, and an hour of equipment downtime may result in losses of tens of thousands of yuan. Therefore, the reliability advantage of plunger pumps is particularly crucial:
The core moving components (plungers, cylinder blocks, valve plates) are made of high-strength alloy materials, and the transmission method adopts "rigid connection", which avoids the "cantilever vibration" problem of centrifugal pump impellers and has a low failure rate. The Mean Time Between Failures (MTBF) can reach 8,000-12,000 hours, which is 2-3 times that of ordinary gear pumps.
The wearing parts of plunger pumps (such as seals, valve groups) are easy to replace without disassembling the entire pump body. Moreover, due to their strong anti-pollution capability, the number of "unplanned maintenance" caused by medium impurities is reduced. Taking the plunger pump for mining hydraulic supports as an example, its annual maintenance cost is only 1/3-1/2 of that of a centrifugal pump.
The "high-pressure + anti-pollution" characteristics of plunger pumps enable them to meet the needs of multiple links in mining sites, eliminating the need for separate equipment selection for different processes and reducing the complexity of equipment management:
- Lifting and driving of hydraulic supports (high-pressure hydraulic oil delivery);
- High-pressure water injection into coal seams (to crush coal seams and improve mining efficiency).
- Transportation of high-concentration ore pulp (e.g., tailings pulp, concentrate pulp);
- High-pressure flotation (to improve mineral separation efficiency).
- Underground high-pressure spray dust suppression (to inhibit dust diffusion and protect miners' health);
- High-pressure filtration of mine water (to remove impurities and realize water recycling).
In summary, in mining site scenarios where there are clear requirements for "high pressure, high reliability, and anti-pollution", plunger pumps are the most cost-effective choice. They can create value for mining sites in three aspects: "operation efficiency, energy consumption, and maintenance costs".
