Diagonal pumps are used to pump incompressible fluids at medium volume flows and delivery heads. Diagonal pumps combine the benefits of axial flow and radial pumps. As with all types of centrifugal pumps, the energy transmission in diagonal pumps is carried out exclusively through flow-related processes.
Diagonal pumps are centrifugal pumps in which the fluid is pumped diagonal to the pump shaft.
The flow mechanism in a centrifugal pump can be generally described as follows: Via an intake connection the fluid flow through the suction nozzle into the rotating impeller due to an energy gradient. The pump unit absorbs mechanical energy from a drive motor via a shaft. The vanes of the impeller permanently attached to the shaft exert a force on the fluid and increase its angular moment. Pressure and absolute velocity increase as a result. Energy is thereby transferred to the medium to be conveyed. The energy which is present in kinetic form as an increased absolute velocity could be converted into additional static pressure energy by a guide mechanism. To maintain the flow the must also be an energy gradient after the pump outlet from the pressure connection, analogous to the pump inlet. Losses occurring in the system, for example due to friction or leakage flows, necessitate an increased power consumption of the pump.
Diagonal pumps differ in their constructive and functional characteristics due to their pre-determined installation location and the liquid to be pumped. For pumps of one model range various installation types may be implemented. The hydraulic characteristics and the pumping performance remain nearly unchanged. Main characteristics are the design of the shaft in the horizontal or vertical position, the position of the pump connections and the connection type of the pump to the drive unit using a coupling or direct assembly on the motor shaft (block design).
Range of applications of a diagonal pump
Diagonal pumps are used when a small outer pump diameter is required.
Therefore diagonal pumps are used at vertical drill holes or multistage process and condensate pumps.
Technical features of a radial pump
- compact design
- direct drive without gearbox (compared to numerous positive displacment pumps / also a benefit regarding efficiency and complexity, repair, maintenance,...)
- dry installation, immersed or submerged
- sealing systems / hermetically with magnetic coupling
Benefits of a diagonal pump
- wide range of applications
- various designs possible
- high efficiencies
- Low susceptibility and low maintenance and repair costs due to simple design (compared to positive displacement pumps)