When it comes to slurry transportation, familiarity with pumps and their parts is par for the course. However, it’s also important to understand what goes into each element of slurry transport. That understanding starts with a few basic questions: “What’s the difference between a slurry pump and a water pump?” “What makes a slurry pump special?” and “What kinds of slurry pump installations are there?”
Slurry pumps versus water pumps
What distinguishes slurry from other fluid types is the presence of a solid — gravel, copper, or sand — within a liquid. Although, in many cases, that liquid is water, a slurry may contain solvents, like acids, alcohols, or petroleum. Those non-water components, whether solids or solvents, make slurry pumps necessary.
In contrast to water pumps’ narrow and often inexpensive components, large replaceable slurry pump parts are made of sturdy, often specialized materials. These parts allow pumps to move nearly any type of solid within a slurry efficiently and safely. Water pumps, on the other hand, lack the hydraulic capacity to move solid particles and are unable to withstand the particle abrasion and chemical corrosion that slurries can cause.
What makes slurry pumps special?
Slurry pumps can withstand extensive wear due to characteristics such as: a large impeller diameter, shafts, bearings, and internal passageways as well as heavy-duty construction. On an industrial level, slurry pump features generate higher upfront and operational costs compared to water pumps. However, only slurry pumps can hydrotransport solid materials efficiently, and the long-term benefits outweigh initial costs.
Centrifugal force pushes something outward when it's spinning rapidly around a center.
Key to slurry pump success is the generation of centrifugal force, which pushes material outward from the pump center. This contrasts with centripetal force, which pushes material toward the center. Slurry pumps must operate on centrifugal principles because the forces that impart velocity to the slurry accelerate the transport process. A centripetal pump, on the other hand, would be impractical since the solids within the slurry would accumulate instead of flowing freely.
Slurry pump installations
Knowing these basics, it’s also important for anyone looking to install a slurry pump to understand the specific environments required for each type of pump. Three types of slurry installations exist:
- Wet — In this installation, the slurry pump and drive are fully submersible. This is necessary for certain slurry pump applications, such as underwater operations.
- Dry — In this installation, the pump drive and bearings are kept out of the slurry. The wet end — which includes the shell, impeller, hub or suction liner, and shaft sleeve or stuffing box — is free-standing and clear of any surrounding liquid. Slurry pump technicians install most horizontal pumps this way.
- Semi-dry — This special arrangement is used for dredging applications with horizontal pumps. Operators flood the wet end and bearings but keep the drive dry. Bearings require special sealing arrangements in this case.
Although this guide provides an overview of slurry pumps and their installations, there’s plenty more to learn. For those who want to better understand slurry pumps and their applications or need help deciding which pump and installation type is best for their applications, KSB GIW, Inc. is here to help.