Pumps are mainly divided into two extensive divisions — positive displacement pumps and dynamic (centrifugal) pumps. Positive displacement pumps use a mechanical way to move or alter the size of the fluid chamber to make the liquid flow. The said momentum creates a boost in flow or pressure at the outlet of the pump.
Meanwhile, centrifugal water pumps transmit momentum to the liquid spinning impellers drenched in the fluid. In the HVAC industry, masterflow.net.au noted that centrifugal pumps are a common preference. Here are its basic characteristics:
Head, Resistance to Flow
The word head is the amount of kinetic energy created by a pump based on the definition used in Newtonian fluids. To understand this concept better, imagine a pipe that shoots a jet of water straight into the air. The head is the overall height the water makes. It measures the length of a liquid column the pump makes because of the kinetic energy it provides.
They purposely used the word head rather than pressure because pressure changes depending on the gravity of the fluid, but the head does not. By using the word head, the industry can explain the performance of a pump on any Newtonian fluid. The head is also connected to the increase in velocity that happens to the fluid when it goes through the pump.
The curve of a pump serves its physical features and it is completely reliant on the location and number of elbows, as well as, the length and size of the pipe. The natural operating point is where the two curves meet and where the pump pressure trails the losses of the system to balance everything. However, if the system frequently faces a process that change, modifying the system parameters or pump characteristics is essential.
Centrifugal pumps require affinity laws and head to function efficiently. HVAC industries must ensure that these two features are working properly to get the most of the system.