A Beginner's Guide To Pumping Slurry

A Beginner's Guide To Pumping Slurry

Centrifugal Pumps for Slurry

Slurry is one of the most challenging fluids to move. It's highly abrasive, thick, sometimes corrosive, and contains a high concentration of solids. No doubt about it, slurry is tough on pumps. But selecting the right centrifugal pump for these abrasive applications can make all the difference in long-term performance.

If you are looking for more details, kindly visit our website.

What Is A "Slurry"?

Slurry is any mixture of fluid and fine solid particles. Examples of slurries include manure, cement, starch, or coal suspended in water. Slurries are used as a convenient way to handle solids in mining, steel processing, foundries, power generation, and more recently, the Frac Sand mining industry.

Slurries generally behave like thick, viscous fluids, flowing under gravity but also requiring pumping as needed. They fall into two general categories: non-settling or settling.

Non-settling slurries consist of very fine particles, which give the illusion of increased apparent viscosity. These slurries usually have low wearing properties but require careful consideration when selecting the right pump since they do not behave like a normal liquid.

Settling slurries are formed by coarse particles that tend to form an unstable mixture. Specific attention must be given to flow and power calculations when selecting a pump. Most slurry applications consist of coarse particles, which have higher wear properties.

Below are common characteristics of slurries:

• Abrasive
• Thick consistency
• Can contain a high amount of solids
• Usually settle quickly
• Require more power to operate than a water pump

Slurry Pump Selection

Many types of pumps can be used for pumping slurries, but the most common is the centrifugal pump. The centrifugal slurry pump uses the centrifugal force generated by a rotating impeller to impart kinetic energy to the slurry, similar to how a water-like liquid moves through a standard centrifugal pump.

Slurry applications greatly reduce the expected wear life of pumping components. It is critical that pumps designed for these heavy-duty applications are selected from the start. Consider the following when making selections:

Basic Pump Components

To ensure the pump will withstand abrasive wear, the impeller size/design, material of construction, and discharge configurations must be properly selected.

Open impellers are the most common on slurry pumps because they’re the least likely to clog. Closed impellers, on the other hand, are the most likely to clog and the most difficult to clean if they clog.

Slurry impellers are large and thick. This design helps them operate longer in harsh slurry mixtures.

Slurry Pump Construction

Slurry pumps are generally larger compared to low-viscosity liquid pumps and usually require more horsepower because they are less efficient. Bearings and shafts must be more rugged and rigid.

To protect the pump's casing from abrasion, slurry pumps are often lined with metal or rubber. For example, Goulds Pumps lines their XHD (Extra Heavy Duty) slurry pump with rubber.

Metal casings are composed of hard alloys, built to withstand the erosion caused by increased pressure and circulation.

Casings are selected based on the needs of the application. For instance, pumps used in cement production handle fine particles at low pressures, so a lighter construction casing is acceptable. If the pump is handling rocks, the casing and impeller will need to be thicker and stronger.

Slurry Pumping Considerations

Those with experience pumping slurries know it's not an easy task. Slurries are heavy and difficult to pump, causing excessive wear on pumps and their components. They are also known to clog suction and discharge lines if not moving fast enough.

Making slurry centrifugal pumps last for a reasonable amount of time is challenging. However, several strategies can extend the life of your slurry pump and mitigate some of the challenges:

• Find the optimal operation speed that allows the pump to run as slowly as possible (to reduce wear) while fast enough to keep solids from settling and clogging the lines.
• Reduce the pump's discharge pressure to the lowest point possible to minimize wear.
• Follow proper piping principles to ensure a constant and uniform delivery of the slurry to the pump.

Pumping slurries presents several challenges, but with proper engineering and equipment selection, long-term operation without issues can be achieved. Working with a qualified engineer when selecting a slurry pump is crucial because slurries can wreak havoc on a pump if not appropriately chosen.

Check out the Must-Have Handbook for Centrifugal Pumps for more information on centrifugal pumps, including details about pumps specifically designed for slurry applications!

Expert Centrifugal Pump Insights from Crane Engineering

Engineers and experts rely on Crane Engineering for insight and assistance with centrifugal pumps to pump slurry. Our in-house team of engineers can answer questions related to pumps, valves, and skid systems. We provide a complete service and repair team who will fix pumps back to OEM standards. We are ready to assist you; contact us today if you're in Wisconsin, Minnesota, Iowa, North Dakota, South Dakota, and the Upper Peninsula of Michigan. Crane Engineering also builds and designs customized skid systems nationwide.

Let us know how we can help you, request a quote today!