Speck pumpen V 430 - 6 Inertisation in the conveying of gases and vapours which contain hydrogen

Speck Pumpen Vakuumtechnik GmbH
zertifiziert: DIN EN ISO 9001
Supplementary Operating Instructions for Explosion Protection
5
open circuit cooling closed circuit cooling
The removal of the compression output takes place
via the supply of cold fresh liquid. The minimum
temperature of the fresh liquid is to be selected so
that a viscosity of 90 mm²/s is not exceeded.
The maximum temperature is to be selected so that
after the mixture with the circulating liquid the
vapour pressure of the operating liquid discharging
on the pressure side is at least 20 mbar less than
the suction pressure.
The removal of the compression output takes place
in a heat exchanger. The minimum temperature of
the circulating liquid at the outlet of the heat
exchanger is to be selected so that a viscosity of 90
mm²/s is not exceeded.
The maximum temperature at the outlet of the heat
exchanger is selected so that the vapour pressure
of the operating liquid discharging on the pressure
side is at least 20 mbar less than the suction
pressure.
Despite the pressure losses on the product side of
the heat exchanger the operating liquid pressure
directly at the compressor should be at least 300
mbar above the suction pressure.
For the separation of the gas and liquid phase front- or state-mounted separators are to be used according
to the specifications of the manufacturer.
6 Inertisation in the conveying of gases and vapours which contain hydrogen
Before the beginning of the process the rotating liquid-ring compressor is to be flushed with inert gas (for
example, nitrogen) with closed suction valve. The amount of flushing gas must correspond to at least
quintuple the internal volume of the system.
Also, after the end of the process before turning off the compressor flushing is to be done in the same
manner with closed suction valve.
Table 6.1 contains the volume specifications for the determination of nitrogen flushing times for the
system, consisting of a liquid-ring compressor of the type series VH, VU or VZ, a front-mounted separator
or side-mounted separator and the associated piping. This applies only for the front- or side-mounted
separators explicitly named by the Speck firm and piping for the integration in vacuum systems for the
conveying of mixtures, which contain hydrogen.