Agriculture Reference
In-Depth Information
Central water
pump
Wall-mounted main station including
pump and satellite. Supplies water to
other satellites and can apply local
hygiene chemicals
Wall-mounted satellites with
user packs, to apply local
hygiene chemicals
Figure 5.5
Demonstration room showing installations of satellite foam and rinse stations (Reproduced with permission from Ecolab.
© Ecolab).
quality changes and/or poorly specified pipe work and
reduction of hygiene chemical choice. However, the lat-
ter point can be remedied by using hybrid centralised/
satellite foam boxes at chosen locations (see Fig. 5.6).
Satellite foam and disinfection systems
are normally
driven by centralised rinse systems using wall-mounted
or trolley-mounted foam boxes equipped with venturi
injectors at each outlet. In low- and medium-pressure
rinse systems (circa 20-40 bar water pressure) utilising
multi-injector satellite stations, compressed air can be
selectively applied at each injector to create detergent
foam and disinfectant spray or foam (Fig. 5.5). It is pos-
sible to have up to four different hygiene chemicals
available for use at one station. In high-pressure rinse
systems (>70 bar), atmospheric air alone can be drawn
in using special venturi foam lances. High-pressure
fixed systems have become less common over the last 10
years; the issues are discussed later under rinsing.
Advantages of low- to medium-pressure satellite foam
systems include the possibility for lower upfront and
running costs (dependent on existing systems), com-
plete versatility of chemical choice/concentration at
each outlet and user safety and comfort. Disadvantages
can include chemical drums in the production area,
though the advent of satellite integrated hygiene chemi-
cal user packs has reduced this hazard and facilitated
removal during production.
The development of direct concentrate dosing into
satellite injectors has enabled the central provision of the
main hygiene chemical of choice, a similar concept to
the traditional central foam system described previously,
but the chemical is not pre-diluted. This allows configu-
ration of a hybrid central/satellite system which com-
bines all the advantages of the two systems (see Fig. 5.6).
Gels
Gel cleaning uses special chemicals and spray equipment
to give a thick, viscous layer of detergent that clings
strongly even on vertical surfaces. This is normally con-
fined to small areas where very long contact time of
several hours is needed for burnt-on or otherwise very
stubborn deposits. Gel chemicals may sometimes be
foamed with certain types of foam equipment, but the
high viscosity of the gel is effectively increased within
the foam even further. This can lead to a slowing down
of the cleaning reactions, which depend greatly on diffu-
sion of detergent components into the soil and of soil
components out of the deposit. For this reason, gels are
not always economical for routine general cleaning of
large factory areas, where time constraints usually dic-
tate contact times of 15-30 minutes. Ensuring complete
rinsing of gels can sometimes be difficult, depending
on the design of the gel and its viscosity change on
dilution.
