Roots* Rotary Lobe Positive Displacement Blowers0 pages

GE Oil & Gas

Roots* Rotary Lobe Positive
Displacement Blowers
Universal RAI* Series | RAM* Series | RCS* Series | DVJ and DPJ Series

Operating Principles

Bi-Lobe Principle
URAI, URAI-DSL, URAI-G, RAM, RCS Series

Two figure-eight lobe impellers mounted on parallel
shafts rotate in opposite directions. As each impeller
passes the blower inlet, it traps a finite volume of air and
carries it around the case to the blower outlet, where
the air is discharged. With constant speed operation, the
displaced volume is essentially the same regardless of
pressure, temperature or barometric pressure. Timing
gears control the relative position of the impellers to
each other and maintain small but finite clearances.
This allows operation without lubrication being required
inside the lobe cavity.

WHISPAIR* Principle
URAI-J, URAI-J DSL, RAM-J, RAM-GJ, RAM-VJ, RCS-J

Incoming air is trapped by the impellers. Simultaneously,
pressurized air (right) is being discharged. As the impeller
passes the wrap-around flange, the Whispair jet
equalizes pressure between trapped air and discharge
area, aiding impeller movement and reducing power.
Impellers move air into the discharge area. Backflow is
controlled, resulting in reduction of noise and pulsation
relative to conventional blowers.

Warranty
Proven designs, manufacturing and material provide
assurance for superior operation. Local, factory trained,
service centers offer timely response to your unique
needs. Roots products are sold subject to GE’s general
terms of sale and warranty policy; contact your nearest
GE office for more information.

DVJ/DPJ Principle
2504 DVJ, RAM DVJ, 721 DVJ, 406 DPJ

Incoming air is trapped between the impellers.
Simultaneously, pressurized air is being discharged.
As the impeller passes the jet plenum, cooled, pressurized
air flows into the space between the impeller and cylinder.
This cools the trapped air, helps control thermal growth
and allows higher pressure ratios. The trapped air is then
moved into the discharge flange. Backflow is reduced,
resulting in lower operating noise level and reduced
shock loading on the equipment.