Honeywell AUTOMATIC CONTROL SI Edition, Engineering Manual

Page: 463 / 512

ENGINEERING MANUAL OF AUTOMATIC CONTROL
DAMPER SELECTION AND SIZING
453
Fig. 17. Typical (Opposed Blade) Damper Construction.
Fig. 18. Graphic Presentation of Leakage Performance.
Fig. 19. Low Leakage Dampers.
LINKAGE
ARM
LINKAGE
ROD
DUAL
LINKAGE ARM
LINKAGE ARM
AXLE SCREWS
THRUST
WASHER
DRIVE
AXLE
BLADE
AXLE
TRUNION
BEARING
DAMPER BLADE
HORIZONTAL
FRAME MEMBER
M10436
AXLE BEARING
VERTICAL
FRAME MEMBER
SIDE
SEAL
0 0.05 0.10 0.15 0.20 0.25 0.30 0.35
0.75
0.50
0.25
0
STATIC PRESSURE ACROSS
DAMPER (kPa)
LEAKAGE IN M
3
/s PER M
2
OF DAMPER AREA (M
2
/s)
LEAKAGE OF A SPECIFIC DAMPER DEPENDS UPON THE HEIGHT AND
WIDTH RELATIONSHIP AS WELL AS THE AREA. THE SHADED AREA
SHOWS THE RANGE OF LEAKAGE FOR A GIVEN AREA.
NOTE:
TORQUE APPLIED TO DAMPER = 6 Nm/m
2
OF DAMPER AREA
M15302
A-DIMENSION LEAKAGE L/s
B-DIMENSION LEAKAGE L/s
A DIMENSION B DIMENSION
TOTAL LEAKAGE =
B-DIMENSION L A-DIMENSION LEAKAGE
WHERE:
A-DIMENSION = OUTSIDE DIMENSION PARALLEL TO
THE DAMPER BLADES
B-DIMENSION = OUTSIDE DIMENSION PERPENDICULAR
TO THE DAMPER BLADES
C3201
DAMPER SIZE IN INCHES
0.5
1.0
1.5
2.0
2.5
3.0
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
3.5
8.5
5
10
15
20
25
30
35
40
45
50
0
0.2 0.4 0.6 0.8 1.0 1.2
LEAKAGE VS DAMPER SIZE
APPLIED TORQUE 6 Nm
FROM ACTUAL TEST DATA
1.495 kPa STATIC
1.246 kPa STATIC
0.996 kPa STATIC
0.747 kPa STATIC
0.498 kPa STATIC
0.249 kPa STATIC