B&C Technologies DP-250 Industrial - Manual (Page 19)

INSTALLATION PROCEDURES
3-5
IMPORTANT: DO NOT use screens or caps on the outside of opening of exhaust duct work.
Figure.3-3 Outside Duct Work Protection
2. Single Dryer Venting
Where possible, it is suggested to provide a separate exhaust duct for each dryer. The
exhaust duct should be laid out in such a way that the duct work travels as directly as possible to
the outdoors with as few turns as possible. It is suggested that the use of 90° turns in ducting be
avoided; use 30° and/ or 45° angles instead. The shape of the exhaust duct work is not critical so
long as the minimum cross section area is provided.
IMPORTANT: Minimum duct size for a gas dryer or 72 Kw electric dryer is
18-inches for a round
duct or 1
6" x 16" for a square duct. The minimum duct size for a steam dryer
or 80 Kw electric dryer is
18-inches for a round duct or 16" x 16" for a
square duct. Duct size must not be reduced anywhere down stream of dryer.
IMPORTANT: Exhaust back pressure measured by a manometer at each basket (tumbler) exhaust
duct area should not exceed 0.3 inches of water column.
It is suggested that the duct work from each dryer (minimum 1
8-inches for a gas dryer or 72
Kw electric dryer and 1
8-inches for a steam dryer or 80 Kw electric dryer) not exceed twenty (20)
feet with no more than two (2) elbows (excluding dryer connections and outside exhaust outlets). If
the duct work exceeds twenty (20) feet or has numerous elbows, the cross section area of the duct
work must be increased in proportion to the length and number of elbows in it. In calculating duct
size, the cross section area of a square or rectangular duct must be increased by twenty (20) percent
for each additional twenty (20) feet. The diameter of a round exhaust duct should be increased ten
(10) percent for each additional fifteen (15) feet. Each 90° elbow is equivalent to an additional
thirty (30) feet, and each 45° elbow is equivalent to an additional fifteen (15) feet.