1. What parameters need to be confirmed before selection?
| Parameters | Selection function |
|---|---|
| Design flow rate, total head | Determine pump specifications, impeller diameter and speed |
| Solid concentration, slurry density | Correct lift, efficiency and motor power |
| Maximum particle size, particle hardness | Determine flow channel size and wear-resistant materials |
| Viscosity, settlement characteristics | Calculate pipeline loss and minimum conveying flow Speed |
| pH value, chemical composition | Judge the corrosion resistance requirements of flow-passing parts |
| Medium temperature | Affect materials, seals and bearing configurations |
| Liquid level, inlet Pressure | Check the suction conditions and NPSH |
| Operating time, installation method | Determine the pump type and maintenance plan |
Reliable selection cannot be completed by providing only "transporting mud". The purchaser should try to provide the media data sheet, pipeline length, elbow valve, inlet and outlet height and continuous operation time.
2. How to determine the flow rate and head?
The total head of the system should include:
Total Head = Static Head + Pipeline Loss + Local Resistance + Outlet Pressure
Slurry density, viscosity and solid concentration will increase pipeline resistance, so clean water conditions cannot be directly applied. The manufacturer's performance curve is usually based on clean water testing, and actual selection requires correction of flow, head, efficiency and shaft power.
For slurries that are prone to settling, the flow rate in the pipe should be higher than the critical settling speed to prevent particles from accumulating in the horizontal pipe; however, too high a flow rate will also aggravate the erosion of the impeller and pipes.
3. How do the properties of particles and media affect selection?
1. Particle size and abrasiveness
The largest particle should be smaller than the allowed particle size of the pump. When containing large particles, fibers or materials that are prone to agglomeration, a wide flow channel and anti-clogging impeller should be selected.
For highly abrasive media such as quartz sand and ore particles, materials such as high-chromium wear-resistant alloys and rubber linings should be considered, and the impeller speed should be controlled. Although the pump type is too small and the speed is too high, it may significantly shorten the life of wearing parts, although it can meet the lift requirement.
2. Corrosion and temperature
Chemical slurries may have both corrosive and abrasive effects. Materials should be selected based on pH value, medium composition, concentration, temperature and chloride ion content. Stainless steel, duplex steel, nickel-based alloys or non-metallic materials can be evaluated. Material hardness cannot only be compared.
4. Horizontal pump or vertical pump?
Horizontal slurry pumps are suitable for systems with fixed pump rooms, continuous transportation and sufficient maintenance space. They are often used for transporting slurry, tailings and circulating slurry.
Vertical or submerged slurry pumps are suitable for tanks, sedimentation tanks and sump pits. The underwater depth, minimum liquid level, cantilever length and sedimentation conditions in the tank should be confirmed. For media that is prone to crystallization or solidification, stirring, flushing, heat tracing or shutdown and emptying measures are also required.
5. How to choose materials and shaft seals?
Highly abrasive slurries can be prioritized for evaluation of wear-resistant alloys or rubber linings; corrosive slurries require material selection based on chemical composition. The specific material grade, hardness, heat treatment process and thickness of wearing parts should also be confirmed when purchasing.
Common shaft seals include packing seals, mechanical seals and auxiliary impeller seals. The packing seal is easy to maintain, but usually requires shaft seal water; the mechanical seal has low leakage and is suitable for chemical projects, but a flushing plan needs to be designed based on particle concentration; the auxiliary impeller seal needs to check the rotation speed and inlet conditions.
6. Why should we check cavitation and motor power?
The slurry pump should meet the following requirements:
NPSHa > NPSHr + Safety Margin
Cavitation may occur if the inlet liquid level is too low, the suction pipe is too long or blocked. When the slurry density is higher than that of clean water, the shaft power will also increase, so the motor power must be corrected according to the actual density and concentration, and a reasonable margin must be reserved.
7. Key Selection Points for Different Applications
Mining and mineral processing projects should focus on particle hardness, wear resistance and replacement cycles of wearing parts; long-distance transportation of tailings should calculate critical flow rates, losses along the way and pipeline pressure; chemical engineering projects should focus on controlling corrosion, crystallization and leakage; high-temperature slurries also need to evaluate thermal expansion, heat tracing and shutdown and emptying conditions.
8. Procurement Suggestions and Feiyue Pump Industry Solutions
Purchasers should require suppliers to provide the corrected performance curve of the slurry, allowable particle size, material description, motor power calculation, shaft seal plan and wearing parts list, and at the same time verify similar working conditions cases and spare parts delivery dates.
Feiyue Pump Industry can assist in determining pump type, flow-passing parts materials, shaft seals and drive configurations based on flow rate, head, particle characteristics, medium temperature and installation conditions, to reduce the risk of wear, blockage, leakage and unplanned shutdown for mining and chemical slurry transportation projects.
