Product Description; Summary; Pump Module; N 2 Gas - EBARA A70W Instruction Manual

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3 Product Description

3.1 Summary

The A Series dry vacuum pump has a compact design and includes various sensors and
controls to enhance reliability and operation.

3.1.1 Pump Module

The pump is a roots-type vacuum pump that rotates a pair of non-contact, multi-stage rotors
synchronized by timing gears. High-capacity units have a Booster Pump (BP) connected in
series with the Main Pump (MP).
A compartment, isolated from the pump casing, encloses the timing gears and bearings,
which require lubrication with Perfluoro-Polyether (PFPE) oil and grease.
The pumps of this series are factory-filled with lubricating oil. Replenish or replace only with
the recommended oil grades shown in Specification Tables 3.1 and 3.2.
3.1.2 N Gas
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Pressurized nitrogen, supplied to the labyrinth seal section, isolates the vapor stream from
the lubricated components, enabling the pump to draw a clean vacuum without admitting
lubricant oil to the pump casing.
Additional N gas, injected in various pump stages, reduces corrosion due to process gas
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and retards the accumulation of reaction byproducts. For processes that do not produce
corrosion or reaction byproducts, the selector valve can stop completely the dilution N flow.
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Adjusting the regulation pressure to the specified value supplies the correct amount of N
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gas for these two types of purge operation.
The pumps of this series are equipped with a dilution N gas control valve. Consult EBARA
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before adjusting the N gas supply to the appropriate level for specific conditions of use.
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(Maximum dilution N flow rate: 76 Pam /s.)
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3.1.3 Cooling Water

Compressing gas from vacuum to atmospheric pressure generates heat. Therefore, cool
motors and casings with cooling water.
Quick-connect cooling water couplers make connection and disconnection easy.

3.1.4 Exhaust

The exhaust check valve, a standard accessory, prevents reverse flow of gas from the
exhaust back through the pump to the vacuum chamber when pump stops. A silencer
(optional) reduces exhaust noise.

3.2 Control System

A Series dry vacuum pumps have a built-in sensing unit consisting of an Earth Leakage
Breaker (ELB), an electro-magnetic switch and a control circuit or an overcurrent circuit
breaker (CB). To improve reliability and safety, sensors monitor the condition of each utility
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