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document no.: X1-25_4.pdf
external exhaust fan
processor
exhaust port
(dis 100mm)
flexible hose or fixed piping system
(dia 100mm)
air flow
position for measurement
As mentioned earlier, to protect the processor as well as any equipment that may be directly interfaced
to or with the processor, the processor must be connected to an external exhaust system.
(failure to correctly ventilate the processor and dryer exhaust will result in corrosion
within the processor and interfaced equipment - in addition, the probability of processor-related film
artifacts is increased). The exhaust system provided at the installation site should comply as follows:-
1)
The disposal of the effluent air must comply with all local environmental safetly codes and regulations.
2)
The following calculation should be used to determine the fficiency of the system provided and that the
the correct amount of end to be connected to the processor. To prevent venturi effect at the duct opening,
all measurements should be made at a point 30cm from the open end of the duct to be attached to the
processor.
3)
Measurement can be made typically using a Dwyer Air Meter (see the image below) If such a device is
not available, contact your local representive for further informations.
4)
If solid metal or rigid plastic ducting is attached to the processor in a manner which would prevent easy
removal, a small hole may be created at a point approximately 30 cm from the processor ventilation
port. The „L“ shaped metal tube provided with the Dwyer Air Meter can then be inserted through the
opening. When measuring negative air, the tube tip opening should be pointed in the direction of airflow
away from the processor. The processor must be de-energized when making air measurements. The air
meter should be held in the vertical position to assure the greatest accuracy. The meter tubing must not be
kinked.
It is most important that negative airflow in the processor exhaust duct remains
constant when the processor is in the run, standby, and shut-down modes.
When processors are installed in darkroom wall openings, it is most important
that darkroom air pressure exceeds the air pressure of the area surrounding
the darkroom This is intended to prevent air cascading through the processor
into the darkroom area. Proper balancing of dark/lighted room air in addition
to correct dryer venting will not only maximize containment of chemical fumes
and vapors within the processor and its dryer exhausting system, but the
incidence of film artifacts occurring in the out-of-solution transport roller
sections will be greatly reduced.To prevent positive airflow from flowing back
into the processor from the building exhaust there should be an air gap not
exceeding more than 5.08 cm (2.0 in.) between the processor exhaust hose
and the building exhaust. thiswill benefit the site in two ways:
1. The gap can be adjusted to provide correct negative flow in cases where
building exhaust exceeds requirements.
2. Prevent positive flow returning to the processor.
Neagtive Static Pressure - Water head
at 100mm tube size:
min 0,76mm - max. 1.02mm
NOTE: If the ventilation tubing is connectet to house-internal exhaust
system, an air-gab of 5cm (2 inch) has to be provided accordinghly.
