U.S. patent number 3,696,804 [Application Number 05/118,261] was granted by the patent office on 1972-10-10 for damper with double floating side rails.
This patent grant is currently assigned to Forney Engineering Company. Invention is credited to Candelario Paredes.
United States Patent |
3,696,804 |
Paredes |
October 10, 1972 |
DAMPER WITH DOUBLE FLOATING SIDE RAILS
Abstract
A damper unit is provided for regulating the flow of hot gases
through a duct opening under high ambient temperature conditions.
The damper blades are provided with a dual floating side rail
arrangement to allow for lateral growth in opposite direction of
the damper blades due to thermal expansion.
Inventors: |
Paredes; Candelario (Dallas,
TX) |
Assignee: |
Forney Engineering Company
(Dallas, TX)
|
Family
ID: |
22377503 |
Appl.
No.: |
05/118,261 |
Filed: |
February 24, 1971 |
Current U.S.
Class: |
126/285R;
251/306; 137/601.17; 137/601.05 |
Current CPC
Class: |
F22B
35/001 (20130101); F16K 1/165 (20130101); Y10T
137/87442 (20150401); Y10T 137/87531 (20150401) |
Current International
Class: |
F22B
35/00 (20060101); F16K 1/16 (20060101); F23l
013/00 () |
Field of
Search: |
;126/285R ;98/110
;137/601 ;251/214,306,308 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Myhre; Charles J.
Claims
What is claimed is:
1. A damper unit for regulating the flow of hot gases and capable
of operation under high ambient temperature conditions comprising a
frame structure having a central opening, bearing means spaced
apart on said frame in opposing relationship, a pair of shafts
journaled in said bearing means for rotation, at least one damper
blade mounted on said pair of shafts and laterally extending across
said central opening, said pair of shafts formed with a pair of
keyways for operatively engaging said damper blade to allow for
lateral movement of said damper blade with respect to said shafts,
said damper blade capable of being rotated to an open and closed
position for respectively allowing the passage and sealing of said
hot gases, a pair of spaced apart sealing bars mounted on opposite
sides of said frame to define sealing channels which are vertically
oriented with respect to the horizontal axis of said shaft, and a
pair of floating side rails positioned in said sealing channels to
abut one end of said damper blade and formed with through bores for
receiving and securing said shaft, said side rails being mounted
for lateral movement in either direction in accordance with the
thermal expansion of said damper blade such that said side rail
extends laterally in the direction of said frame and provides
complete sealing action against the passage of hot gases when said
damper blade is in said closed position.
2. A damper unit according to claim 1 in which pins are mounted on
said damper blade and positioned in said keyways for lateral
movement.
3. A damper unit according to claim 1 in which a pin is positioned
in each of said keyways, said keyways having an elongated
configuration, such that said pins govern said lateral movement in
either direction.
4. A damper unit for regulating the flow of hot gases and capable
of operation under high ambient temperature conditions comprising a
frame structure having a central opening, bearing means spaced
apart on said frame in opposing relationship, a pair of spaced
apart shafts journaled in said bearing means for rotation, at least
one damper blade mounted on said shaft and laterally extending
across said central opening, said damper blade capable of being
rotated to an open and closed position for respectively allowing
the passage and sealing of said hot gases, a pair of side rails
positioned in said central opening to abut one end of the damper
blade and formed with through bores for receiving the shaft, a pair
of upstanding sealing bars mounted on said frame to define a
sealing channel, said side rails being mounted in said sealing
channel for lateral sliding movement in either direction, each of
said shafts formed with an elongated keyway, and a pin positioned
in said keyway and mounted on said damper blade, whereby said side
rails extend laterally in either direction under thermal expansion.
Description
BACKGROUND OF THE INVENTION
In the operation of large vapor generator installations, high
temperature precision damper units are used to regulate the flow of
hot gases. The damper construction which is most usually employed
consists of a series of damper blades, each of which is
individually mounted on a shaft such that the blades can form a
gas-tight barrier across a duct opening when in a closed position.
The damper blades are generally formed with an air foil shaped
blade arrangement such that the blades can be positioned side by
side in the duct opening to form a barrier to the hot gases when in
a closed position. The damper blades also lend themselves to
adjustment into various intermediate positions to regulate the flow
of hot gases through the duct. With this type of aerodynamic blade
construction it is possible to bring the lateral edges of adjacent
blades together to form a gas-tight seal. However, due to high
temperature conditions, the damper blades tend to expand and
contract along their lateral axis. This can cause leakage of the
hot gases as well as binding of the damper shaft in its bearings,
such that free rotational movement of the damper is
constrained.
There has been provided a single sliding rail arrangement for
allowing the damper blade to laterally expand in one direction, as
shown in U.S. Pat. No. 3,525,328.
In order to prevent gas leakage and obtain free damper blade
rotation, when operating under relatively high and varied
temperature conditions, the ends of the damper shaft are each
mounted on a floating side rail capable of moving laterally in
either direction in accordance with the thermal expansion and
contraction of the damper blade along its lateral axis. In this
manner, complete sealing action against the passage of hot gases is
provided when the damper blade is in the closed position, and the
damper shaft is capable of rotation in the floating side rails
during these periods of expansion and contraction of the damper
blade.
SUMMARY OF THE INVENTION
In accordance with an illustrative embodiment demonstrating
features and advantages of the present invention, there is provided
a damper unit for regulating the flow of hot gases which is capable
of operation under high ambient temperature conditions. A frame
structure is provided with a central opening and bearing means are
spaced apart on the frame in opposing relationship. A pair of
shafts are journaled in the bearing means for rotation, and at
least one damper blade is positioned on the pair of shafts and
laterally extends across the central opening. The shafts are each
provided with a keyway for operatively engaging the damper blade
and to allow for lateral movement of the damper blade with respect
to the shafts. The damper blade is capable of rotation from an open
to a closed position for respectively allowing the passage and
sealing of the hot gases. Positioned in the central opening to abut
both ends of the damper blade is a pair of side rails having
through bores for receiving the shaft. The sealing bars are mounted
in the bearing means for lateral movement in both directions in
accordance with the thermal expansion of the damper blade. Thus,
the side rail extends laterally in both directions and provides
complete sealing against the passage of hot gases when the damper
blade is in the closed position.
BRIEF DESCRIPTION OF THE DRAWINGS
The above brief description as well as further objects, features,
and advantages of the present invention will be more fully
appreciated by reference to the following detailed description of a
presently preferred but nonetheless illustrative embodiment in
accordance with the present invention when taken in connection with
the accompanying drawings wherein:
FIG. 1 is a front elevational view of a portion of a high
temperature damper unit of the instant invention which is shown
completely removed from the duct arrangement with the broken lines
showing the shafts including the pin and slot arrangement;
FIG. 2 is an enlarged sectional view of the damper unit which is
shown in FIG. 1, with portions broken away in order to clearly show
the double floating side rail arrangement prior to lateral
expansion or contraction thereof;
FIG. view similar to FIG. 3 is a partial sectional view of the
damper unit shown in FIG. 2 to illustrate the damper blade in a
fully expanded position; and
FIG. 4 is a partial sectional the but with the damper blade in a
fully retracted position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now specifically to the drawings there is shown in FIG. 1
a damper unit construction employing features of the present
invention and generally designated by the reference numeral 10. The
damper unit 10 includes a frame structure 12 having a central
opening 14 with bearing means 16 spaced apart in opposing
relationship on frame structure 12. A pair of shafts 18 are
journaled in bearing means 16 for rotation, and damper blades 20
are mounted on shafts 18 to extend laterally across central opening
14. The damper blades 20 are capable of being rotated to an open
and closed position for respectively allowing the passage and
sealing of hot gases. The bearing means 16 includes a rotational
bearing 24 positioned between a pair of end collars 26. A
conventional linkage arrangement which has not been shown in the
drawings can be mounted on the end of one of the shafts 18 for
conjointly moving the damper blades 20.
Positioned in central opening 14 is a double floating side rail
arrangement, generally designated 30, which abuts the end of damper
blade 20. In accordance with the present invention, the double
floating side rail assembly 30 is mounted for lateral movement in
accordance with the thermal expansion of damper blades 20, such
that the double floating side rail assembly 30 extends laterally in
either direction with respect to the frame structure 12 and
provides complete sealing action against the passage of hot gases
when damper blades 20 are in the closed position.
As shown in FIG. 2 the frame structure 12 includes a vertical
upstanding support 32 and a cover plate support 34 which are
jointed together by means of welds 36 to form a hollow chamber 38.
The supports 32 and 34 are provided with aligned bores 40 for
receiving the shafts 18.
As previously indicated, the double floating side rail 30 of the
present invention is an improvement of the single damper floating
side rail bar of U.S. Pat. No. 3,525,328. Accordingly, the instant
double floating side rail 30 includes a pair of side rail bars 42
with coupling pin 96 and slot means 44 operatively connecting the
damper shafts 18 to the side rail bars 42 for lateral movement in
either direction.
In FIG. 2 there is shown one of the side rail bars 42 which
includes a spring seal 46 mounted on a cylindrical collar 48. The
spring seal 46 is integrally formed with a shoulder 50, through
bores 52 and a pair of upright side walls 54. A pair of stationary
sealing angle bars 58 are mounted to the outer face of the
upstanding support 32 to form a sealing channel 62. The side rail
bars 42 are fabricated from resilient metal such that the upright
bars 54 bear against the sides of angle bars 58 in sealing channel
62. In this manner, a gas-tight seal is provided between each of
the upright side walls 54 and the respective adjacent angle bars
58.
Mounted on upstanding support 32 is a stuffing box housing 64 which
is packed with a heavy lubricant 66 and has an axial bore which is
coaxially aligned with through bore 40 for rotatably receiving
shaft 18. The stuffing box housing 64 is provided with a cover
plate 68 which is removably secured by through bolts 70.
As best shown in FIG. 2, the damper blade 20 is formed with a
horizontal, reinforced edge 72 for coaxially receiving a
cylindrical sleeve 74 which is machined with an internal bearing
surface 76 and stop shoulder 78. The cylindrical sleeve 74 can be
secured to reinforced edge 72 by various conventional means of
fabrication such as press-fitting or spot welding.
The shaft 18 is integrally formed with an enlarged cylindrical
section 80, a shoulder 82, and a reduced cylindrical section 84.
The enlarged cylindrical section 82 has a horizontal length which
corresponds to the size of hollow chamber 38 and the reduced
cylindrical section 84 is sized to receive a ferrule bearing 86.
The ferrule bearing 86 is formed with an internal bearing surface
88, which is sized for sliding movement on reduced cylindrical
section 84, and an annular shoulder 90 for mounting the spring seal
46 against the reinforced edge 72 and cylindrical sleeve 74. The
shaft 18 also is provided with an elongated keyway 92 which is
aligned with the horizontal axis of shaft 18. The reinforced edge
72, cylindrical sleeve 74 and ferrule bearing 86 are formed with
vertically aligned through bores 94 which pass through keyway 92
for mounting a pin 96.
The lateral extremities of keyway 92 are defined by an expansion
edge 97 and a contraction edge 98, and the pin 96 is positioned in
keyway 92, such that it will bear against expansion edge 97 when
the blade 20 is in the fully expanded position and against
contraction edge 98 when the blade 20 is in the fully retracted
position. This expanded and contracted position of the pin 96 in
keyway 42 can best be seen in FIG. 3 and FIG. 4, respectively.
While the damper unit 10 has been shown with a single pin 96, it is
also possible to utilize two spaced-apart pins positioned in
accordance with the lateral movement of side rail bars 42 in
sealing channel 62 during thermal expansion and contraction of the
damper blade 20.
By progressively inspecting FIGS. 3 and 4, the manner in which
thermal expansion causes lateral growth to the damper blade 20 on
the shafts 18 can be appreciated. The damper blade 20 is shown in
FIG. 4 prior to the occurrence of thermal expansion and the
attendant lateral growth, with the spring seal 46 and pin 96
located in the outermost extended position in the sealing channel
62, and keyway 44, respectively. Thus, the pin 96 is brought to
rest against contraction edge 98. In accordance with the present
invention, the spring seal 46, reinforced edge 72, and sleeve 74,
which are mounted on ferrule bearing 86, slide laterally in either
direction on the shafts 18 due to thermal expansion and
contraction. This can be readily appreciated from the movement of
spring seal 46 in sealing chamber 62 and function of the pin and
slot means 44 which includes the pin 96 moving in the keyway 94.
Thus, in the fully expanded position of FIG. 3, the pin 96 is
brought to rest against expansion edge 97.
From the foregoing, it can be appreciated that thermal expansion
from intensive heat causes lateral growth to the damper blades 20
on the shafts 18. By providing the pin and slot coupling means 44
and double floating side rail assembly 30 located at opposite ends
of the damper blade 20, it is possible for lateral growth to occur
in both directions with respect to the frame structure 12. In FIG.
2 the damper unit 10 is shown in a non-expanded position for one
side of the unit, while FIGS. 3 and 4 illustrated the fully
expanded and contracted position of the damper unit 10.
Accordingly, by allowing for lateral growth in either direction
along a horizontal axis with respect to frame structure 12, the
damper unit 10 in accordance with the present invention affords a
gas tight seal against the flow of hot gases without impairing the
free rotation of the damper blades 20.
A latitude of modification, change and substitution is intended in
the foregoing disclosure and in some instances some features of the
invention will be employed without a corresponding use of other
features. Accordingly, it is appropriate that the appended claims
be construed broadly and in a manner consistent with the spirit and
scope of the invention herein.
* * * * *