Solids handling and slurry pumps are designed to transfer liquids containing suspended solids, abrasive particles, fibres, sludge or delicate product pieces without excessive blockage, wear or product damage.
AxFlow UK supplies slurry pumps, sludge pumps and solids handling pumps for wastewater, mining, chemical processing, food and beverage, anaerobic digestion, paper, ceramics and general industry.
There is no single pump technology that is best for every solids application. Reliable selection depends on the size, shape, concentration and hardness of the solids, together with fluid viscosity, abrasiveness, flow, pressure and whether the product must remain intact.
What is a solids handling pump?
A solids handling pump is designed to move a liquid containing suspended or entrained solid material.
Typical products include:
- Wastewater sludge and sewageSand, grit and mineral slurry
- Mine tailings
- Lime slurry
- Digestate
- Paper stock and fibres
- Ceramic slip and clay
- Paints and pigments
- Food pieces and agricultural products
- Chemical precipitates
“Solids handling pump” describes the application rather than one specific pump design.
A pump suitable for abrasive mineral slurry may be completely unsuitable for fragile food pieces, while a pump designed for sludge may struggle with long fibres or rags.
Why are slurries and solids difficult to pump?
Solids-containing fluids create several challenges that are less significant when pumping clean liquids.
Blockage and ragging
Large, fibrous or irregular solids can become trapped in impellers, valves, suction lines and other restrictions.
Abrasive wear
Sand, grit, minerals and other hard particles can erode impellers, casings, hoses, rotors, stators and seals.
Settling
Dense solids can settle in pipework when transport conditions are unsuitable, creating deposits and eventual blockage.
High viscosity
Sludge and concentrated slurry may be much more difficult to feed into a pump than the carrier liquid alone suggests.
Product damage
Food pieces, crystals, biological material and other delicate solids may need to pass through the pump without being broken down.
The correct pump therefore has to be selected around the solids and the complete pumping system, not simply flow and pressure.
Which pump is best for slurry and solids?
Different technologies solve different solids-handling problems.
| Pump technology | Best suited to | Consider carefully when |
|---|---|---|
| Recessed impeller / vortex | Sludge, fibres, grit, irregular solids and entrained gas | Efficiency and wear are major priorities |
| Screw centrifugal | Thick sludge, large or stringy solids and shear-sensitive products | Higher head or very abrasive duties dominate |
| Chopper pump | Rags, fibres and solids that can be deliberately reduced in size | Solids must remain intact |
| Peristaltic hose pump | Abrasive slurry, high solids, lime, filter-press feed | Very high continuous flow or pulsation is undesirable |
| Progressive cavity pump | Viscous sludge, controlled flow and higher-pressure transfer | Frequent dry running or severe abrasion at high speed |
| AODD pump | Portable, intermittent and variable slurry transfer | Energy efficiency at large continuous duties is critical |
| Rotary lobe pump | Viscous solids-bearing fluids and delicate products | Highly abrasive mineral slurry |
| Lined centrifugal pump | Corrosive and abrasive slurry at higher flows | Very high viscosity or difficult large solids |
When should you select a slurry or solids handling pump?
Specialist solids-handling technology should be considered when:
The liquid contains abrasive particles
Wear-resistant materials, reduced operating speeds or a pump where wear is concentrated in a replaceable component can significantly improve reliability.
Large or irregular solids are present
The pump's true free passage must accommodate the largest realistic particle without creating frequent blockage.
The product contains fibres or rags
Vortex, screw centrifugal, chopper or other specialist designs may be required depending on whether the solids should pass intact or be reduced in size.
The slurry is highly viscous
Progressive cavity, peristaltic and other positive displacement technologies can become more suitable as viscosity increases.
The solids are fragile
Low-shear pumps can help protect food pieces, biological solids, crystals and similar products.
Flow must remain controlled as pressure changes
A positive displacement pump may be preferable to a conventional centrifugal pump where predictable volumetric delivery is important.
Solids handling pump applications
Water and wastewater
Typical duties include sewage, primary and secondary sludge, screenings, grit, polymer, dewatered sludge and industrial effluent.
Mining and minerals
Slurry pumps are used for mineral slurry, tailings, sand, clay, lime and other highly abrasive products where wear resistance is particularly important.
Chemical processing
Chemical slurries may combine abrasion with corrosion, making both pump geometry and materials selection critical.
Food and beverage
Food products containing fruit, vegetables, grains or other pieces often require gentle pumping to maintain product quality.
Anaerobic digestion and agriculture
Digestate, manure, biomass and fibrous feedstocks can require large free passages or cutting capability to reduce blockages.
Ceramics, paints and paper
Clay, ceramic slip, pigments, paper stock and coatings can combine high viscosity, solids and abrasion, making pump selection particularly application-specific.
Why Choose AxFlow?
With decades of experience supplying pumps to the process industry, AxFlow selects pump technologies based on the specific process rather than a single product range. Our engineers help breweries and distilleries improve reliability, reduce maintenance and ensure hygienic, efficient handling of solids and slurries throughout production.
