BUSCH COBRA ATEX, Instruction Manual

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2 | Product Description
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NOTE
Technical term.
In this instruction manual, we consider that the term ‘machine’ refers to the ‘vacuum
pump’.
2.1 Operating Principle
The machine works on the one-stage, twin-screw pump principle.
Two screw rotors are rotating inside the cylinder. The pumped medium is trapped
between the cylinder and screw chambers, compressed, and transported to the gas out-
let. During the compression process, the two screw rotors do not come into contact with
each other nor with the cylinder. There is no need for a lubrication or an operating fluid
in the compression chamber.
2.2 Application
The machine can be used to draw gas mixtures and hydrocarbon gases.
Explosive gases and vapour mixtures can be drawn in according to the scope of the Dir-
ective ATEX 2014/34/EU.
The machine is intended for the suction of explosive gases and for the placement in a
potentially explosive environment according to the nameplate.
The ATEX classification:
Inside (i)
Outside (o) 2G IIB T4 X
2G IIB T4 X
II
In case Busch delivered the machine without motor and coupling, the following must be
observed:
• In regards to its explosive atmosphere protection class, the motor and the coup-
ling must have at least the same ATEX classification as the machine for the outside
area “Outside (o)”.
The machine is capable of maintaining ultimate pressure, see Technical Data [ ► 33] .
The machine is suitable for continuous operation.
Permitted environmental conditions, see Technical Data [ ► 33] .
2.3 Standard Features
2.3.1 Cooling
The machine is cooled by a cooling liquid circuit in the cylinder cover and cylinder.
The screw rotors are cooled by injection of cooling liquid into the cylinder.