I. Overview of AH Type Slurry Pump
1.1 What is an AH type slurry pump?
The AH type slurry pump is a horizontal single-stage single-suction cantilever centrifugal slurry pump, belonging to the universal slurry pump series designed in accordance with ISO international standards. Its design is derived from the AH series slurry pumps of Warman Company. After long-term engineering verification and continuous optimization, it has become the standard equipment for slurry transportation in the mining and metallurgical industries worldwide.
"AH" is the series code. Here, "A" stands for horizontal installation, and "H" represents the high-head design (compared to the low-head series like M type). The complete model representation method is "diameter + series code". For example, "100AH" indicates an AH-type slurry pump with an outlet diameter of 100mm.
2.The positioning of the AH type slurry pump
| Flow rate range | 3.6 - 13200 m³/h |
| Head range 5 - 95 m | Maximum rated power |
| Approximately 1100 kW | Maximum allowable through-particle size |
| Approximately | 30% - 40% |
| Applicable slurry concentration (by weight) | ≤ 60% |
II. Working Principle
2.1 Centrifugal Conveying Principle
The core working principle of the AH type slurry pump is centrifugal force transportation. The motor drives the impeller to rotate at high speed through the shaft. The slurry enters the center area of the impeller (i.e., the suction inlet of the impeller) from the pump inlet along the axial direction. Under the action of centrifugal force, it is thrown towards the outer circle of the impeller. The slurry gains kinetic energy and pressure energy in the impeller channel, and then enters the water pressure chamber (Blade casing). Under the guiding effect of the Blade casing, the flow velocity decreases and the pressure increases, and finally it is discharged from the pump outlet.
The entire energy conversion process can be summarized as:
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Electrical energy of the motor → Kinetic energy of the impeller → Pressure energy of the volute → Slurry transportation
2.2 The Fundamental Difference Between Slurry Pumps and Clear Water Pumps
| Comparison item | Water pump | AH type slurry pump |
| Impeller type | Spiral water storage chamber | Circular or quasi-spiral shape, facilitating the passage of solids |
| Gap Design | Small sealing gap | Large sealing gap to prevent particle blockage |
| Material Selection | Cast iron / stainless steel | High chromium alloy / rubber lining |
| Sealing method | Mainly mechanical seals | Secondary impeller seal / packing seal / mechanical seal |
3.Sealing components of the shaft
The function of the shaft seal is to prevent the high-pressure slurry inside the pump from leaking outwards along the shaft. The AH type slurry pump offers three types of shaft seal solutions:
**(1) Packing Seal**: Composed of packing, packing rings, and packing covers. The structure is the simplest, but there will inevitably be leakage, and the packing needs to be adjusted and replaced regularly.
**(2) Secondary Impeller Dynamic Sealing**: An additional impeller is installed on the rear side of the main impeller. During operation, a negative pressure zone is formed in the sealing chamber, preventing the slurry from leaking out. When the machine is shut down, the sealing is maintained by an auxiliary seal (packing or mechanical seal).
**(3) Mechanical Seal**: It achieves sealing through the end face contact of the moving ring and the stationary ring. This method offers the best sealing effect but has the highest cost, and it requires strict installation accuracy.
