Section II - General Description
Displacement/volumetric flow rate
For the relevant pressure range, when a QSV pump operates at quasi constant motor
speed (rotations per minute) and since the compression chambers have fixed dimensions,
the same volume of air is pumped from inlet to outlet with falling pressure level. Over
the relevant pressure range, this makes the volumetric flow rate quasi independent of
the vacuum level. It is the expression of the flow rate inside the piping at the governing
vacuum level (Acfm), And always higher than the throughput in mass flow rate.
Throughput in mass flow rate
Even if the volumetric flow rate is quasi unchanged with falling pressure level, the
number of molecules in that pumped volume is not. By definition: the deeper the
vacuum, the lower the amount of molecules in the same volume of air. This means that
the mass flow will decrease with decreasing (absolute) pressure. It is clear that a flow rate
must be stated at a certain vacuum level when using this denotation.
Introduction
The QSV 205 up to QSV 530 are single-stage, oil-sealed screw vacuum pumps driven by
an electric motor.
The vacuum pumps are controlled by the Quincy Airlogic Graphic regulator (ER).
The regulator is fitted to the front door. An electric cabinet (1) comprising fuses,
transformers, relays, etc. is located behind this door.
The vacuum pumps use Variable Speed technology. This means: automatic adjustment of
the motor speed, depending on the process demand.
The vacuum pumps are air-cooled and are enclosed in a sound-insulated bodywork.
Figure1 Front view
Quincy Vacuum Pump-QSV Series
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