Spencer Power Mizer Multistage Centrifugal Cast Blowers - Manual (Page 3)

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Product Description
Spencer Power Mizer blowers are multistage centrifugal units
which handle air and other gases, working either as blowers or
exhausters. They increase the pressure of the incoming air or
gas by guiding it from one stage to the next through diffusers.
They are centrifugal because the flow through the blower is
turned perpendicular to the axis of rotation.
The blower casing has three main sections constructed of
cast iron: inlet, return channels and discharge. The inlet and
discharge are flanged and drilled to ANSI 125#/150# standards.
External steel tie rods hold the return channels between the
inlet and discharge sections. There are no external moving
parts except the shaft that connects to the power source–typi-
cally an electric motor, but other drivers such as a steam tur-
bine or internal combustion engine are available.
The internal rotor assembly consists of a steel shaft supporting
cast aluminum alloy impellers with varying combinations of
radial and backward curved blades. The impellers are indi-
vidually dynamically balanced, then keyed to the shaft and
the impeller/spacer stack is secured with a locknut. Finally,
the complete rotor assembly is checked to be sure the total
amplitude of vibration is no more than 0.23 in/sec at the
bearing housing.
The rotor assembly is supported at both ends by antifriction
bearings designed for an L-10 bearing life of 100,000 hours.
Depending on intended blower use, either labyrinth seals or
carbon ring seals are provided. See page 7 for Shaft Seal
discussion.
Series 7000 and 8000 blowers are also equipped with an
internal balance piston. As the largest Power Mizer models,
these blowers develop high differential pressures with corre-
spondingly high thrust loads. The balance piston is designed to
lessen the thrust load, protecting the bearings from overloading.
II. Limited Warranty
We warrant that this product will be free from defects in mate-
rial and workmanship for a period of 18 months from date of
shipment or 12 months from date of startup, whichever comes
first. Within the warranty period, we shall repair or replace,
F.O.B. our Factory, such products that are determined by us to
be defective.
This warranty will not apply to any product which has been
subjected to misuse, negligence or accident, or misapplied or
improperly installed. This warranty will not apply to any product
which has been disassembled, repaired or otherwise altered
by any persons not authorized by the Spencer Service
Department.
The guarantees of the motor, control and component manufac-
turers govern the extent of our guarantee on such equipment.
Warranty work on motors, controls and components must be
authorized by Spencer and must be performed in an autho-
rized shop as designated by the motor, control and component
manufacturers. The Spencer Turbine Company reserves the
right to invoice all expenses incurred when repairs are made in
the field at the specific request of a customer.