Well it is very important factor in fluid mechanics.
The term comes often in compressors and Pumps.
Displacement means change of place( Fluid ), Positive displacement means at all points of operating the discharge will be the same where as the discharge in non positive displacement varies at various operating points.
For clear idea on the above compare the reciprocating pump with centrifugal pump at various operating points (by throttling) discharge valve).
I hope you are asking about non-positive displacement air compressors.
The air compressors are broadly classified into
1. displacement (positive) compressors.
2. steady flow or non-positive displacement compressors.
DISPLACEMENT COMPRESSORS:
In this type of air compressors air is compressed by being trapped between two engaging surfaces.
NON-POSITIVE DISPLACEMENT COMPRESSORS:
Compression occurs by transfer of kinetic energy from a rotor.
No. :/
compressor work on two principles 1)reduce volume of a constant amount of gas 2)adding more gas in a constant amount of volume positive displacement compressor works on first principle it reduces the volume of gas by applying force on it but gas amount is constant in every stroke or rotation thus increasing the pressure. centrifugal compressor work on second principle it adds more amount of gas in a given constant volume thus the pressure increase.
A positive displacement pump causes a liquid or gas to move by trapping a fixed amount of fluid or gas and then forcing (displacing) that trapped volume into the discharge pipe. Positive displacement pumps can be further classified as either rotary-type (for example the rotary vane) or lobe pumps similar to oil pumps used in car engines.Moreover,these pumps give a non pulsating output or displacement unlike the reciprocating pumps and hence are called positive displacement pumps
yes.only positive displacement pumps can be used in hydraulics
A positive displacement compressor consisting of one male and one female rotor which contain lobes that when meshed together reduce the amount of available space for the refrigerant gas to occupy, thus compressing it. The male rotor is usually the drive rotor.
compressor uses centrifugal force for compressing air is known as non positive displacement compressor- examples are vortech, paxton, pro charger, rotex, any turbo.
A reciprocating compressor is called a positive displacement compressor because it works by trapping a volume of gas and then reducing the volume to increase the pressure. This process ensures a constant flow rate and is based on the principle of displacing a fixed amount of gas with each stroke of the piston, hence the term "positive displacement."
An air compressor which is used to compress air in a cylinder, that is reducing the volume and increasing the pressure of air is known as positive displacement air compressor. It is used for the compression process in IC engines.
A positive displacement pump moves a constant volume of fluid for each cycle of operation, creating flow by direct displacement. In contrast, a non-positive displacement pump does not move a constant volume of fluid per cycle and relies on factors like speed and pressure to generate flow.
Positive displacement pumps deliver a constant amount of fluid per rotation of the pump shaft, regardless of pressure. Non-positive displacement pumps do not have this characteristic and can vary in flow rate depending on the system pressure. In positive displacement pumps, the fluid is confined in a chamber and discharged with each stroke, while non-positive displacement pumps rely on kinetic energy to push fluid through the system.
what is the piston displacement of a compressor with 2" bore and 3" strokes
air operated- spring return
The two main classification of Air Compressor are. 01) Positive Displacement Type. 02) Dynamic Type. 01)Positive Displacement Type Air Compressor. Positive displacement types compressor are those who mechanically displace a fixed volume of air into a reduced volume.The constant volume can be delivered by compressor when operated at fixed speed.The discharge pressure is determined by the system load conditions.If the consumption of air is more then discharge pressure falls below the cut-off pressure & compressor works on load condition. Dynamic Type Air Compressor. The Dynamic Type Air Compressors mechanically impart velocity to the air.This action is produced by the Impellers rotating at a high speed,in enclosed casing.The air is forced into a progressively reduced volume.The volumetric flow will vary inversely with the differential pressure across the compressor.
No. :/
compressor work on two principles 1)reduce volume of a constant amount of gas 2)adding more gas in a constant amount of volume positive displacement compressor works on first principle it reduces the volume of gas by applying force on it but gas amount is constant in every stroke or rotation thus increasing the pressure. centrifugal compressor work on second principle it adds more amount of gas in a given constant volume thus the pressure increase.
A kinetic displacement compressor is a type of compressor that uses a combination of kinetic energy and displacement to increase gas pressure. It works by converting kinetic energy into potential energy, which is then used to compress the gas. This type of compressor is commonly used in gas turbine engines and certain industrial applications.
Reciprocating compressors are positive displacement in machines. However, separable compressors have higher maintenance costs.