Milnor 7272TG1L, Installation And Service

Page: 43 / 206

How to Size Inlet and Discharge Air Ducting
PELLERIN MILNOR CORPORATION
the perforations inside the cylinder. This will also effectively reduce the actual airflow
through the goods and thus drastically reduce productivity.
2. Do not employ “turning vanes” in any external ducts connected to your machine.
Turning vanes may quickly clog with lint. Lint buildup in the ducts will reduce the airflow
and the dryer's performance, and also cause a
fire hazard!
3. Do not employ right angle elbows. Use only elbows with radii no smaller than that shown in
FIGURE 1.
4. Adequately sized inspection covers should be placed near every elbow for the periodic
removal of lint.
5. All transitions should be smooth. Transitions may be considered as straight duct if the taper is
less than 7 1/2 degrees.
6. Because the resultant varying pressure drop will prevent the machine from performing
correctly, never connect two or more machines to a common exhaust duct.
7. Two or more machines may be connected to a common powered wet or dry type lint
collector , providing:
• Separate ducts must be run from each machine to the collector, and,
• The lint collector's fan capacity must be capable of accommodating the maximum
combined flow from all machines connected to it. The lint collector must have a variable
speed motor or other equivalent means responsive to the number of dryers actually
running to maintain a constant back pressure not greater than .5" (13) water column, nor
less than zero.
8. This information is intended to be general in nature and is provided only as a guide.
MILNOR accepts no responsibility nor liability resulting from the use of this information.
You may find it advisable to employ the services of a professional engineer licensed to
practice in your area.
Figure 1: Values Used in Table of Duct Sizes
Do not use right angle elbows Round elbow
Rectangular elbow Legend
.
A. R = 1.5 D (long round
elbows)
B. R = D (short round
elbows)
D. Diameter
H. Height
R. Radius
W. Width
37