What Does Positive Displacement Blower Mean?
A positive displacement blower is a type of pump that uses fluid displacement as its primary mechanism for pumping fluid from the blower’s inlet to its outlet. Fluid (liquid or gas) is drawn into a fixed-volume compartment at the inlet where a reciprocating or rotary motion is used to push controlled amounts of fluid through the outlet.
A positive displacement blower is also known as a positive displacement pump.
Trenchlesspedia Explains Positive Displacement Blower
During hydro excavation, the negative pressure produced at the inlet pumps the slurry mixture from the excavated site into the holding tank. Since positive displacement blowers operate at a constant flow rate and are driven by kinetic/mechanical actions, these pumps tend to be more suitable for fluids with high viscosities such as slurries, oils, greases, creams, etc.
These blowers are also self-priming; in other words, they can be started without having liquid in their displacement chamber. This attribute makes positive displacement blowers better suited for liquids with high amounts of entrained air without running the risk of cavitation often seen in fan-type blowers.