Brochure

velocity is transformed into pressure) and the
return passage to channel gas to the eye of
the next impeller. The discharge diaphragm
forms the diffuser for the last impeller as well
as the discharge volute. The diaphragms are
usually horizontally-split.
In the small to medium sizes of the MCL series,
the upper half of the diaphragms is fixed to the
upper half casing to facilitate inspection, and
for the large sizes, it is fixed to the lower half of
the diaphragms, while the barrel family
internals are assembled into a bundle which
can be easily extracted from the casing.
The diaphragms are made of cast-iron, steel or
stainless steel and when practical 100%
machined to improve efficiency.
Easily removable labyrinth seals are installed
on the diaphragms at impeller shrouds, to
prevent return flow from discharge to suction
and on the shaft sleeves to eliminate
interstage leakage.
Rotors
The rotor consists of shaft, impellers, sleeves,
balance drum and thrust collar. Impellers are
selected from a number of standard families.
Each family groups a set of geometrically
similar impellers with different flow
coefficients to meet specific flow
requirements. All geometries have been
tested in the company’s R & D laboratories.
Impellers are shrunk on the shaft. Impellers
may be either of the closed or open design.
Closed impellers are made of forged steel.
Their blades may be welded or brazed to
both the disc and the shroud or milled from a
solid disc and welded or brazed to the shroud.
Solid weld-free impellers produced by milling
or electrical discharge machining technology
are also available.
The blades are generally back-swept to
different angles in accordance with the
required performance.
Open impellers are machined from solid
forgings.
Each impeller is dynamically balanced and
overspeed tested before assembly.
The rotor is balanced after the assembly of
each individual component on the shaft.
15 GE Centrifugal & Axial Compressors