What is the purpose of a slurry pump?

A slurry pump is a type of pump designed for pumping liquid containing solid particles. Slurry pumps changes in design and construction to adjust to multiple type of slurry which varies in concentration of solids, size of solid particles, shape of solid particles, and composition of solution. Slurry pump are more robust than liquid pumps; they have added sacrificial material and replaceable wear parts to withstand wear due to abrasion.

Want more information on Heavy Duty Slurry Pump? Feel free to contact us.

Centrifugal, positive displacement, and vortex pumps can be used for slurry. Centrifugal slurry pumps can have between bearing-supported shafts with split casing or rubber- or metal-lined casing. Configurations include horizontal, vertical suspended and submersible.

Slurry is usually classified according to the concentration of solids. Engineering classification of slurry is more complex and involves concentration, particle size, shape and weight in order to determine abrasion severity. For engineering selection of slurry pumps, slurry is classified as class 1, class 2, class 3 and class 4.

Selection of slurry pumps is more difficult than selection of pumps for water and liquids. Many factors and corrections to the duty point affect brake horsepower and wear. Root-dynamic Centrifugal Slurry Pumps (ANSI/HI 12.1-12.6-2016) provides methods for calculation of slurry pumps. The peripheral speed of the impeller is one of the main features and classification of slurry pumps. Speed must be in accordance with the slurry type classification (abrasion classification) in order to maintain a reasonable life in service due to high abrasion of solids.

Before selecting an appropriate slurry pump the engineers considers capacity, head, solids handling capacity, efficiency and power, speed and NPSH.

Slurry pumps are widely used in transport of abrasive solids in industries such as mining, dredging, and steel. They are often designed to be suitable for heavy-wearing and heavy-duty uses. Depending on the mining process, some slurries are corrosive which presents a challenge because corrosion-resistant materials like stainless steel are softer than high-iron steel. The most common metal alloy used to build slurry pumps is known as "high chrome", which is basically white iron with 25% chromium added to make it less brittle. Rubber line casings are also used for certain application where the solid particles are small.

Components

[

edit

]

Impeller

The impeller, either elastomer, stainless steel or high-chrome material, is the main rotating component which normally has vanes to impart the centrifugal force to the liquid.

Casing

Split outer casing halves of cast contain the wear liners and provide high operation pressure capabilities. The casing shape is generally of semi-volute or concentric, efficiencies of which are less than that of the volute type.

Shaft and Bearing Assembly

A large diameter shaft with a short overhang minimizes deflection and vibration. Heavy-duty roller bearing are housed in a removable bearing cartridge.

Shaft sleeve

A hardened, heavy-duty corrosion-resistant sleeve with O-ring seals at both ends protects the shaft. A split fit allows the sleeve removed or installed quickly.

Shaft Seal

Expeller drive seal, Packing seal, Mechanical seal.

Types

[

edit

Are you interested in learning more about Lined Slurry Pump? Contact us today to secure an expert consultation!

Suggested reading:
The Ultimate Guide to Choosing metallurgy slurry pump manufacturer

]

Submersible

Submersible slurry pumps are placed at the bottom of a tank, lagoon, pond, or another water-filled environment, and suction solids and liquids right at the pump itself. The materials are taken in at the intake and passed through a hose connected to the discharge valve.

Self-Priming

A self-priming slurry pump is operated from land, and a hose is connected to the pump's intake valve. The self-priming pump draws the slurry to the pump then discharges the material from there.

Flooded Suction

The flooded suction slurry pump is connected to a tank or hopper and uses gravity to move slurry and liquid from the enclosure. Located at the bottom or below the water, the pump uses the force of gravity to continuously fill the pump and then passes the material out through the discharge valve.

Pumps designed for pumping slurries will be heavier duty than those designed for less viscous liquids since slurries are heavy and difficult to pump.

Slurry pumps are typically larger in size than standard pumps, with more horsepower, and built with more rugged bearings and shafts. The most common type of slurry pump is the centrifugal pump. These pumps use a rotating impeller to move the slurry, similar to how a water-like liquid would move through a standard centrifugal pump.

Centrifugal pumps optimized for slurry pumping will generally feature the following in comparison to standard centrifugal pumps:

• Larger impellers made with more material. This is to compensate for wear caused by abrasive slurries.
• Fewer, thicker vanes on the impeller. This allows the passage of solids more readily — typically 2-5 vanes, compared to 5-9 vanes on a standard centrifugal pump.

For pumping abrasive slurries, these types of pumps may also be made from specialized high wear alloys such as AL-6XN® or Hastelloy® C-22®. Hardening stainless steel is also a common option for abrasive slurries, with Expanite and Armoly being two hardening processes.

For certain types of slurry pumping conditions, positive displacement pumps may be a more appropriate choice than a centrifugal-style pump.

These conditions include:

• A low slurry flow rate
• A high head (i.e., the height to which the pump can move liquid)
• A desire for greater efficiency than that afforded by centrifugal pumps
• Improved flow control

Common types of positive displacement pumps used in slurry pumping applications include:

Rotary Lobe pumps

These pumps use two meshing lobes rotating within a pump's housing to move fluids from the pump's inlet to its outlet.

Twin-screw pumps

These pumps employ rotating screws to move liquids and solids from one end of the pump to another. The screws' turning action creates a spinning motion that pumps material.

Diaphragm pumps

These pumps use a flexible membrane that expands the volume of the pumping chamber, bringing in fluid from an inlet valve and then discharging it through an outlet valve.

Selecting and operating a slurry pump

Choosing the right pump for your slurry application can be a complex task due to the balance of many factors including flow, pressure, viscosity, abrasiveness, particle size, and particle type. An applications engineer, who knows how to take all of these factors into account, can be a great help in navigating the many pump options available.

~ Matthew Sato, Applied Products Sales Manager, Ampco Pumps

In determining which type of slurry pump is best suited for your particular application, follow these four simple steps.

If you want to learn more, please visit our website slurry pump bearing assembly.