Principle
of Operation:
The
Fuji Ring Compressor is a non-positive displacement, high
volume, low pressure blower that can operate as either a compressor
or a vacuum pump. It is also known by other names such as:
regenerative blower, vortex blower and side-channel blower.
The
blower consists of an impeller mounted directly on a motor
shaft and is rotated at a high speed, about 3600 RPM. On the
periphery of the impeller is a large number of radial blades.
The impeller is positioned between two endplates with the
blades located with a channel on either side.
As
the impeller spins and the blades pass the inlet port, a low
pressure area is created that draws in air or other gases.
The impeller blades impart motion to the air by centrifugal
force, throwing it outward and forward, where it follows the
contour of the side-channel and is returned to the base, or
root, of the impeller. This action is repeated many times,
creating a vortex. Each "regeneration" causes the
air to gain pressure until it reaches the portion of the housing
where the air is stripped from the impeller and discharged
from the blower.
The
ring compressor is, in effect, a multistage compressor with
each regeneration of the air becoming another "stage".
The pressure increase at each stage in the cycle is very small,
but the large number of stages yields inlet vacuum levels
up to 8 in. Hg and discharge pressures of up to 5 PSIG, depending
on the size of the blower. Flow levels of up to 570 SCFM can
be achieved, and discharge air is free of annoying pulsating.
The
basic construction of a ring compressor means that the only
moving part is the impeller. Nothing touches except the bearings.
The method of compression means that there is no requirement
for lubrication in the compression chamber; the discharge
air is oil-less. No oil aerosols are present in the discharge
air, nor carbon dust generated by sliding vanes. The blowers
may be mounted vertically (with impeller housing down) or
horizontally.
Construction
Fuji's
complete line of ring compressors is designed to meet the
most critical application requirements. Each features an impeller
mounting base and housing manufactured of aluminum alloy for
maximum strength, reduced weight and increased corrosion resistance.
The compressor and motor are constructed as a unit for mechanical
simplicity and maximum structural integrity. The elimination
of clutches, gears, belts, and sliding vanes reduces periodic
maintenance while increasing reliability.
TEFC
(totally enclosed, fan-cooled) motors are standard on all
models, except VFC063P and VFC100 models, which are TENV (totally
enclosed, non-ventilated. In addition, all models have NEMA
class B, or class F (model VFC704), insulation, and are Underwriters
Recognized (Yellow Card File), CSA certified (File LR48762),
and meets CE. All single phase units have built-in automatic
reset thermal protectors, except models VFC400P and VFC500P.
All three phase units have pilot duty thermal protectors requiring
only the addition of an external contactor for overload protection,
however, magnetic motor starters are recommended.
All
ring compressor impellers are dynamically balanced to virtually
eliminate vibration while increasing overall long-term reliability.
Most models have a shaft oil-seal between the impeller and
bearing, as well as a double shielded bearing to reduce the
possibility of foreign material influx and preclude air contamination.