Vertical Turbine Pumps
Vertical Turbine Pumps
Vertical turbine pumps are centrifugal pumps specially designed to move water from an underground well or reservoir. They’re also known a deep well turbine pumps or a line shaft turbine pumps. While submersible pumps have an electric motor located underwater at the bottom of the pump. However, the electric motor of a vertical turbine pump is located above ground, connected via a long vertical shaft to impellers at the bottom of the pump. Despite the name, these pump types have nothing to do with turbines.
Instead the vertical turbine pumps are typically driven by an A.C. electric induction motor or by a diesel engine through a right angle drive. The pump end consists of at least one rotating impeller attached to a shaft that directs the well water into a diffuser casing (i.e. bowl).
Multi-stage configurations use several impellers on the same shaft. Doing so creates the higher pressure necessary for deeper wells, or higher pressure (head) required at ground level. Vertical turbine pumps work when water enters the pump through a bell-shaped part at the bottom called the suction bell. From there it moves into the first stage impeller, which increases the water’s velocity. The water then enters the diffuser bowl immediately above the impeller, where this high velocity energy is converted into high pressure. The bowl also directs the fluid into the next impeller, located directly above it.
After the water exits the last diffuser bowl, it passes through a vertical column pipe as it rises up the well bore toward the surface. The spinning shaft inside this column is supported at three- or five-foot intervals with internally mounted sleeve bushings that are lubricated by the water moving past them. The pump discharge head is at the surface, allowing the flow to change direction and move towards the discharge pipe. A vertical, high thrust A.C. motor is mounted above the discharge head.
Vertical turbine pumps are primarily used in places where it’s impossible to use submersible pump. This is usually because either the flow is above the range of turbines, or because the owner prefers a conventional top-mounted motor.
Vertical turbine pumps used in bored wells to provide agricultural or turf irrigation. They’re also employed ground water supply for municipalities that don’t rely on surface water, and they can be used to provide plant make-up water and fire water for industrial plants.
Vertical turbine pumps aren’t only used in bored wells. They can also pump from an open body of water such as a reservoir, river, or pump intake structure. They can be mounted on top of a tank in industrial settings, and can also be fixed inside a barrel for better control over suction source pressure versus atmospheric pressure. In the latter configuration, the pump can function as a booster pump for boosting municipal water supply, or in an industrial application where the pressure (head) must be boosted. It can also take suction from a vessel under vacuum, such as a hot well condensate pump application.
The flows of vertical turbine pumps range from approximately 50 gpm to 30,000 gpm and higher. Because the pump can be built with one stage or many, the amount of head generated can be customized. These advantages make it one of the most common types of centrifugal pumps.
Contributed by PumpScout.com staff.