Ettlingen, January 2003
GEA Jet Pumps offers technologies to be used in energy-saving vacuum
processes.
Especially in cases of application where a large amount of water vapour and
little inert gas (leaking air) must be compressed against atmosphere from a
vacuum between 1 to 5 mbars, GEA Jet Pumps offers two processes of the GEA
group which present excellent possibilities of saving operating costs:
a) The combination of the steam jet vacuum pump with a liquid ring vacuum
pump and a water cooling system. In comparison with conventional steam jet
vacuum pumps, the performance of the ejector prestage (booster) can be chosen
considerably lower, as the condenser is operated with cold water and,
consequently, the condenser pressure can be decreased.
Depending on the steam/electricity costs, the operating costs of such a
vacuum system can be reduced by more than 50 %. The process is
environmental-friendly, i.e. the waste water quantity is low; the cooling water
circuit is closed except for the waste water discharge. Typical cases of
application are found in the Edible Oil industry.
b) In the Edible Oil industry as well, "dry condensation" or "ice
condensation" is used. This process is offered by our affiliated company Niro
A/S --> www.niro.dk
Dry condensation operates below the triple point, i.e. water directly
changes from the vapour phase into the solid phase. The vacuum systems are
designed for 1.5 mbar abs. (corresponding to -29° C). Three tubular systems
operate alternately as precondenser, in which the product vapour is condensed
on the tubes as ice.
At predefined intervals, a condenser is isolated from the process and is
defrosted. Another apparatus takes over the function of condenser in the
meantime.
These precondensers are vented by steam jet vacuum pumps, which are
dimensioned considerably smaller than the conventional ejectors used for
operation at the deodorizing tower, as only leaking air needs to be drawn off.
In this way it is possible to reduce the steam consumption by 90 % or more.