B&C Technologies DP-250 Industrial - Manual (Page 24)

INSTALLATION PROCEDURES
3-10
Figure.3-7 Multiple exhaust connection.
CAUTION: Improperly sized or installed exhaust duct work can create a potential fire hazard.
Where possible, it is desirable to provide a separate exhaust air duct for each dryer. The duct
should go as directly as possible to the outside air. Avoid sharp 90
o
right-angle turns in the ducting;
use 30
o
or 45
o
angles, instead. The radius of the elbows should preferably be 1-1/2 times the
diameter of the duct. To protect the outside end of the duct from the weather, it may be bent
downward as indicated. Leave at least twice the diameter of the duct as clearance between the duct
opening and the nearest obstruction. If the exhaust duct goes through the roof, it may be protected
from the weather by using a 180
o
turn to point the opening down. Allow at least twice the diameter
of the duct as clearance from the nearest obstruction. Do not use screens or caps on the outside
opening of the exhaust duct. The ducting should be smooth inside with no projections from sheet
metal screws or other obstructions which will collect lint. When adding, ducts, the duct to be added
should overlap the duct to which it is to be connected. Provide inspection doors for periodic clean-
out of lint from the main duct.
If it is not feasible to provide separate exhaust ducts for each dryer, ducts from the
individual dryers may be channeled into a common main duct. Each dryer is provided with a back
draft damper. The individual ducts should enter the bottom or side of the main duct at an angle not