Operating Principle And General Information; Description; Applications - MIL'S EVISA E65.R Betriebs- Und Wartungshandbuch

1.

OPERATING PRINCIPLE AND GENERAL INFORMATION

1.1.

Description

The EVISA ATEX-type pumps are lubricated-vane vacuum pumps, EC marked II 2G IIB T4 and/or II 2D IIIC
T135° according to Directive 2014/34/EU.
(1) suction / start of filling (2) maximum filling volume (3) compression and exhaust phase
The gas is sucked in through the suction filter (optional), the protective screen and the built-in valve, to fill
the inlet section of the pump (1). The centrifugal force resulting from rotation of the rotor forces the vanes
against the inner wall of the pump body, thereby forming three chambers leading to a succession of
variable volumes that create a vacuum and flow.
During phase (1), oil is injected for lubrication, sealing and cooling purposes. It can either be injected
directly or passed through an oil filter prior to injection. The gas / oil mixture is delivered from the body
through the exhaust valve to the exhaust unit where a first gas / oil separation takes place. Oil is removed
from the gas by coalescence in the separating filter, then the gas discharged outside the pump. An
automatic drain with float re-injects the oil separated by the separating cartridge into the body of the
pump.
EXHAUST
517976-05
EVISA ATEX E65.R / E100.R / E200.R / E300.R
SUCTION
SUCTION
COMPRESSION
EXHAUST
When the pump is stopped, the suction valve prevents the entry of air and transfer of oil to the system
under vacuum. Bypassing of the exhaust valve enables the body to be brought to atmospheric pressure to
avoid oil accumulating in the body and thereby prevent irregular oil injection at start-up.
Gas ballast prevents the condensation of water vapour in the pump in the event of reduced vapour suction.
1.2.

Applications

These vacuum pumps are used to vacuum a process designed to withstand vacuum (0.05 mbar absolute).
The operating range of these pumps extends from atmospheric pressure to the limit vacuum of the pump
in continuous running.
These vacuum pumps are designed for operation:

From atmospheric pressure to the maximum continuous vacuum rating of the pump,

In ATEX zone (type 1): probable risk in normal operation (10 < duration < 1000 h/year),

With an ambient temperature between +5°C and +40°C,

With a GAS-type fluid compatible with Group IIB (ethanol type) and especially with Group IIA
(propane type),

With vapours or mixtures containing less than 21% oxygen,

With an atmosphere or a GAS-type fluid compatible with a maximum permissible surface
temperature of class T4.

With dusty atmosphere zone 21- (occasionally in normal operation) type IIIC (conductors).

With dust atmosphere zone 22- (rarely and for short periods) type IIIB (non-conductive).
The use of these pumps is exclusively reserved for the suction of non-aggressive gases, any
damage linked to a different use will not be considered as part of the contractual guarantee,
and in particular:

The pumping of gases containing more than 21% oxygen

The pumping of corrosive gases

The pumping of not compatible with IIB group gases

The pumping of a substance tending to sublimation

The use of spare parts or lubrication oils other than those validated by the MIL'S
company

The use of the pump as a compressor

Sodium azide pumping
If there is any doubt as to the compatibility of the suctioned products, the user must carry
out an exothermic reaction risk analysis.
So, an ATEX atmosphere (defined by the lower and upper explosion limits for gases and vapours) can be
sucked in only between 10 and 1000 h/year.
The customer must therefore imperatively engage on the type of zone or must accept our
material with full knowledge of the facts.
These pumps are not intended to be installed outdoors, but only in a room protected from bad weather,
cold and extreme climatic variations.
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