POINT EXTRACTION

The tornado principle is the most effective. When
the tornado hood is positioned over the basin and
is switched on, the necessary air velocity and
direction will be established. Another advantage
is that it can be equipped with a slit in the front
and top plates, so that a crane hook can get in
over the basin.
A rear edge extractor can also be used, but this is
more sensitive to any cross currents. At the same
time, it is likely that, if the distance from the rear
wall to the front of the basin is relatively large,
then greater amounts of air will have to be used
than with a tornado.
In the case of very small cleaning basins, it is possible
to use an extractor duct placed either on a
swing arm or with magnets.
Figure 12
Suggestion for suction in the galley
In the galley, it is necessary to establish point extraction in the form of an extractor fan over cookers,
deep fryers, ovens etc. See figure 5 and the example on page 20.
The amount of air used should be adapted to the actual consumption. It is not unusual that about 1,000
cubic metres of air per hour is removed from a small galley. In a small room it can be a problem to supply
replacement air without exposing crewmembers to draughts and without the extraction effect being
ruined by cross currents of air.
Sector specific guidance The Danish Maritime Occupational Health Service:
Point extraction - Suggestions for suction over cleaning processes
15