The various kinds of industrial pumps work in different ways. Generally speaking, all pumps use the basic forces of nature to move a liquid or material. When the moving pump element begins to move, air is pushed out of the way. The movement of air then creates a vacuum, which can be filled up by more air, or another fluid or material. Positive displacement pumps and dynamic pumps work in different ways, as outlined below.
Positive Displacement Pumps
Positive displacement pumps are known as ‘constant flow’ pumps as they will not adjust their flow rate, despite discharge pressure. Different types of positive displacement pumps work in slightly different ways:
- Gear Pumps: Gear pumps consist of at least two separate and rotating gears with intermeshing teeth. As these meshed teeth separate, they create a partial vacuum which is filled by the fluid being pumped. There are a number of different gear pump designs, but ultimately, they all operate using the same pumping principle. They are the most common pump for clean oils and other viscous liquids.
- Screw Pumps: Screw pumps use two intermeshing screws, driven by gears, in order to move oils and other viscous liquids. It creates a partial vacuum by the opening and closing or sweeping of a series of voids or volumes. Screw pumps are good for transferring fuels as well as for other jobs requiring relatively high flow rates of viscous liquids.
Dynamic pumps are a type of pump in which kinetic energy is added to the material or fluid by increasing the flow velocity. The increase in energy is then converted to a gain in potential pressure when the velocity is reduced as the material exits the pump into the discharge pipe.
- Centrifugal Pumps: Centrifugal pumps are very simple; whenever the pump is in action, then the fluid pressure will increase from the inlet of the pump to its outlet. The change of pressure will drive the liquid throughout the system.
- Drum And Barrel Pumps: Drum and barrel pumps have a vertical shaft where the pump is located on one end and a narrow tube with a pumping element on the other end. This makes it easy to fit inside the lid of the drum or container to transfer thin to medium viscosity fluids. They are designed to provide a safe and simple way to transfer almost any chemical from containers such as barrels or drums.
- Self-Priming Pumps: Self-priming pumps are a versatile solution to negative suction head applications. These pumps are typically horizontal, one-stage, with a centrifugal design. They operate with an open impeller handling large solids. These pumps are normally equipped with externally lubricated mechanical seals with hard faces to prevent seal damage during dry running.
At Applied Pumps, we are experts in all types of industrial pumps. For advice on the best pumps for your application, get in touch today.