There are a hundred different types of pumps available in the market these days. From diaphragm pumps to positive displacement pumps, you name the application and you will find a pump suitable for it! The most commonly used pump type however is the centrifugal pump. Centrifugal pumps come with an impeller. This impeller when spins, transfers energy to the fluid with the help of centrifugal force. It directs the water to the discharge point.
A type of centrifugal pump that can pump solids is known as trash pump. It can pump materials like those in a typical sewage pipeline. What differentiates a trash pump from a normal centrifugal pump is the impeller and the pump casing. The impeller has the solid-handling capacity and is sized accordingly to let spherical solids pass through it.
Importance of Impeller in a Pump
Impellers have blades that help in adding velocity to the fluid. When the impeller moves, the length of the blades which are also known as vanes control the pressure produced by the pump, while the width of the blades control the volume.
When you are buying your industrial pumps, you must always review the construction applications and your industry type so that you can buy a pump with specific impeller configurations. An open or semi-open impeller offers more space for non-compressible solids such as rocks up to 5 inches in diameter to pass through it. These types of impellers reduce the risk of clogging. Open impeller designed trash pumps can be used for a wide range of applications including wastewater and other industrial fluids.
For open impellers, cast steel is the best material that can be used since it provides excellent impact resistance when non-compressible solids pass through them. An open impeller with a cutter vane can also prevent clogging as discussed earlier.
When dealing with smaller solids, one can use a closed impeller since it is also better equipped to handle abrasives and slurries. Fine rocks encountered during mining applications can pass through this type of impeller.
While selecting a trash pump, you must know the maximum depth of the fluid and then consider the installation method. Trash pumps are normally available in two installation methods:
Generally, above-the-ground trash pumps are driven by an engine or with electricity and submersible pumps are hydraulically or electrically driven. Any of the installation methods will have its own advantages and limitations.
Trash pumps were originally designed to pump solids. The impeller design is such that the cavity of the blades is large. Hence, when compared to other centrifugal pumps, trash pumps can take higher capacities of fluids. Therefore, if your application requires a high volume of fluid to be pumped, you must consider buying a trash pump. With the introduction of impellers of large diameters, liquids can be pumped at a longer range on high pressure. This makes the trash pumps more versatile. From an owner’s perspective, having one pump that can work on multiple application projects reduces the overall cost and need to service and replace different units if any problems arise.