US3198235A

US3198235A - Air register with movable vanes

Info

Publication number: US3198235A
Application number: US257616A
Authority: US
Inventors: John S Maskell
Original assignee: Babcock and Wilcox Ltd
Current assignee: Babcock International Ltd
Priority date: 1962-02-28
Filing date: 1963-02-11
Publication date: 1965-08-03
Anticipated expiration: 1982-08-03
Also published as: GB958907A

Description

3, 1965 J. 5. MASKELL 3,198,235

AIR REGISTER WITH MOVABLE VANES Filed Feb. 11, 1963 3 Sheets-Sheet 1 lNVENTOfi John S. Maskelfl ATTOIQA E) Aug. 3, 1965 J. s. MASKELL AIR REGISTER WITH MOVABLE VANES 3 Sheets-Sheet 2 Filed Feb. 11, 1963 Aug. 3, 1965 J. s. MASKELL AIR REGISTER WITH MOVABLE VANES 3 Sheets-Sheet 5 Filed Feb. 11, 1965 United States Patent Ofi ice 3,198,235 Patented Aug. 3, 1965 AIR REGETER WETH MUVAELE VANES John S. Maslreil, London, England, assignor to Bannock & Wiieox Limited, London, England, a British company Filed Feb. 11, 1963, Ser. No. 2.526%. Claims priority, appiication Great Britain, Feb. 28, N62,

7,814/62 1 (Ilaims. (ti. S--1.5)

This invention relates to air registers for pulverized fuel or other fluent fuel burners. When a furnace is fired by a group of burners, it may be desirable to whirl the streams of secondary air from the respective burners in different senses in order to attain optimum furnace conditions and l the most advantageous arrangement of the directions of whirl is best determined by observation and trial. In conventional registers of the kind having a circular series of pivotally mounted dampers, the dampers are capable of effecting whirling of the entering air in one direction only and this lack of flexibility is a great disadvantage when change in the direction of whirl at a burner is desired.

An object of the invention is to provide an improved register which enables the direction of Whirl to be changed Without replacing the register.

An air register in accordance with the present. invention has a circular series of pivotally mounted dampers provided with alternative pivotal supports affording different axes of rotation selectable in order to enable the dampers to be rotated from their closed positions either in one sense about one axis of rotation or in the opposite sense about the other axis of rotation.

The invention will now be described, by way of example, with reference to the accompanying drawings in which:

FIGURE 1 is a front elevation of a burner register with the top half in section showing the dampers closed but depicting for one of the dampers different damper operating positions by means of dotted lines;

FIGURE 2 is a side View, with some of the actuating mechanisms omitted for the sake of clarity, of the register, the top half of which is in section on the line IIII of FIGURE '1; and

FIGURE 3 is a fragment of FIGURE 1 drawn to a larger scale.

Referring to the drawings, the burner register contains a front plate 2 (disposed on the left side of FIG. 2 away from the furnace chamber 3) provided with an opening 8 and with openings 7 for sight tubes and an annular rear plate 4 (on the right side of FIG. 2 and near to the furnace chamber 3) with a rearwardly convergent throat 6 secured to the inner periphery of the plate 4. Extending between, coaxial with and welded to the plates is a cylindrical peripheral wall 14. Secured to the rear plate 4 is a rearwardly extending cylindrical member 52 formed with a radial end flange St) for retaining packing 54 disposed between the member 52 and an aperture in the furnace chamber wall. A pulverized fuel burner 9 passes through the opening 8 and projects into the throat 6 for the discharge of fuel therethrongh, the flow of fuel being from left to right as viewed in FIG. 2 and as shown by the arrow 5. j

The air register has a circular series of pivotally mounted dampers 12 provided with pivotal supports affording different axes of rotation which enable each damper to swing open from its closed position in one sense about its axis of rotation or in the opposite sense about the other axis of rotation. The dampers 12 are shown by full lines in FIGURES 1 and 3 in their closed positions. In FIG- URE 3 one of these dampers is depicted by dotted lines at 12' and 12" in alternatively fully open positions, and at 12A and 12A in alternative partly open positions, the

dampers having been rotated from the closed position to the position in 12' or 12A about an axis of rotation and to the position 12" or 12A about the other axis of rotation.

The dampers 12, which are of rectangular shape, are evenly spaced around and are curved to conform with the curvature of the cylindrical peripheral wall 14 of the register, which wall is formed with apertures 15 rectangular in shape and of size somewhat less than that of the dampers 12. The dampers 12 when in their closed position seal the apertures.

The axes of rotation of each damper 12 are circum ferentially spaced from one another and located at opposite edges of the damper parallel to the axis of the register. Thus each damper is provided at opposite edges with respective hinge pins extending parallel to the axis of the register and projecting at each end beyond the damper to provide trunnion like ends. A damper moving mechanism is connected with the damper at a location between the said axes.

To ensure that the dampers properly overlap respective apertures 15 in the register peripheral lwall 14 guides are provided on the dampers 12 adjacent their forward and rearward edges which tend to centralize the dampers in relation to the apertures 15 during the closing movements of the dampers. Thus each damper 12 is provided with a pair of brackets 31 having outwardly projecting arms 33 which are slightly convergent and which are adapted to engage respective adjacent sides of the associated aperture 15 in the register peripheral wall 14 towards the termination of the closing movement, in order, if necessary,

to urge the damper 12 in a forward or a rearward direction towards its proper position.

The pivotal supports defining the axes of rotation of each damper includes hinge pins or

pivotal supports

16 and 16 arranged to engage in respective open seatings 18 provided on brackets 17 secured to the wall 14 and to be maintained in the said seatings by retaining members 2%. Each retaining member has alternative retaining positions and co-operates with

hinge pins

16 and 16 at the adjacent edges of neighboring dampers 12. Thus in one of the alternative positions shown in full lines the retaining members 20 are effective in maintaining the hinge pins 16 in the open seatings 18, the hinge pins 16' being free, and in the alternative positions shown in FIGURE 3 by dotted lines the retaining members are effective in maintaining the hinge pins 16 in the open seatings 18, the hinge pins 16 being free. By moving the retaining members from the full line positions the hinge pins 16 may be released from the seatings 1S and by moving the retaining members from the dotted line positions the hinge pins 16' may be released from the seatings 18.

The hinge pins 16 or in are positioned with play by the retaining members 20 in the seatings 18 so that binding of the hinge pins is avoided and proper seating of the dampers 12 when in the closed position is facilitated.

The open seatings 18 are formed with inwardly converging sides 18' so that when a damper 12 is rotated about one hinge pin 16 or 16' to close the damper the entry of the ends of the other hinge pin into the associated open seatings 18 is facilitated. The open seatings 13 for the

hinge pins

16 or 16 at the adjacent edges of each pair of neighboring dampers are defined at the forward and rearward edges of the dampers by outward abutments 22 and an intermediate abutment 24 and rotatably mounted in the forward and rearward intermediate abutment 24 is a spindle 26 carrying forward and rearward retaining members 20 for co-operating withthe open seatings 13 at'opposite sides of the intermediate: abutment 24., The retaining members 2%) are located close to respective abutments and each spindle 26 carrying its respective retaining members 29, extends through the front plate 2 of the register and is provided outside the register with an arm 28 which is fastened by a screw 45 to one or the other of two lugs 47 on the front plate 2 to secure the retaining members 20 in one or other of its retaining positions.

If desired, the spindles 26 carrying the retaining members 20 may be extended across the windbox and through the windbox front plate, the arms 28 for holding the retaining members 20 in one or other retaining position being provided at the ends of the spindles on the outer side of the said front plate so that the retaining members 2i) may ,be selectively positioned without entry into the windbox. One of the spindles 26 is provided with an extension 26 passing through the front plate of the windbox and carrying at its outer end a pointer (not shown) for showing the axis about whichthe associated damper 12 is set to rotate and hence the direction of whirl produced by the dampers.

The actuating gear for each damper includes a threaded rod 32 pivotally connected by means of a clevis 34 to a lug 36 secured to the damper at the center thereof. Screwed onto the rod 32 is a nut 38 connected by a crank 40 to a-shaft 43 rotatably mounted in apertures in the front and back plates of the air register, extending parallel to the axis thereof and projecting through a peripheral part of the register front plate 2.

The shafts 43 of the actuating gear for the dampers 12 are secured at their ends to respective triangular-shaped crank members 44 which are pivotally connected to driving links 46. One of the crank members 44A is formed with an arm connected by a link 48 to an operating crank 49 on an operating shaft 56 so that rotation of the shaft rocks the crank members 44 in unison to operate the dampers 12 together. If desired the arms 28 may be suitably coupled to common actuating means either inside or outside the windbox so that they may be rocked in unison by the actuating means from one position to the other.

In order to minimize air leakage packing is provided for improving the sealing action of the dampers 12. As shown the packing is in the form of woven asbestos strip 19 secured on the inner side of the peripheral wall 14 of the register around the apertures 15 therein and serving to provide seatings 11 for engagement by the dampers 12. Other suitable packing material such as Inconel metal strips may be used instead of woven asbestos.

Individual adjustment of each damper 12 in relation to its seating 11 may be eifected through rotation of the nut 38 on the threaded rod 32 but some compensation for lack of adjustment is afforded by the torsional flexibility of the part of the spindle 43 between the crank 40 connected to the nut 38 and the crank member 44 at the end of the spindle 43. Since the threaded rod 32 is connected to the center of the damper 12, the latter is evenly pressed throughout its periphery against its seating 11.

From the above description it will be understood that the same actuating mechanism serves to operate the dampers 12, whether each damper is rotatably supported by one hinge pin 16 for whirling of the air in one direction or by the other hinge pin 16 for whirling of the air in the opposite direction.

7 In use, the direction in which the air is whirled may expeditiously be changed simply by shutting dampers 12 re moving the screws 45 clamping the arms 2% at the ends of the spindles 26 of the retaining members 20, rotating the spindles 26 to locate the retaining members 2t) in their alternative operative positions and reclamping the arms 28 in their newly adjusted positions.

It will be appreciated that a furnace chamber will generally be provided with a plurality of burners having air registers as described above.

I claim:

1. An air register of circular cross-section comprising a plurality of circumferentially arranged dampers, means for supporting each damper including a pair of pivotal supports affording ditferent axes of rotation for said 4 damper, a means for selectively securing one of said supports so that it rotates substantially only about its axis of rotation while permitting free movement of the other of said supports, and means for rotating said damper about the axis of rotation of the fixed support.

2. An air register of circular cross-section comprising a plurality of dampers forming a part of and being distributed about a peripheral wall of said register when in their closed position, means for supporting each damper including a pair of pivotal supports affording different axes of rotation for said damper, means for selectively securing one of said supports so that it rotates substantially only about its axis of rotation while permitting free movement of the other of said supports, and means for rotating said damper about the axis of rotation of the fixed support.

3. An air register of circular cross-section comprising a plurality of dampers forming a part of and beingdistributed about a peripheral wall of said register when in their closed position, means for supporting each damper including a pair of pivotal supports affording different axes of rotation for said damper, each damper being rectangular in Shape and being curved to substantially conform to the curvature of said wall, means for selectively securing one of said supports so that it rotates substan-' tially only about its axis of rotation while permitting free movement of the other of said supports, and means for I rotating said damper about the axis of rotation of the fixed support.

4. An air register of circular cross-section having a central axis comprising a plurality of circumferentially arranged dampers, means for supporting each damper including a pair of pivotal supports aifording different axes l of rotation for said damper, said pivotal supports being spaced apart from one another and being parallel to said central axis, means for selectively securing one of said supports so that it rotates substantially only about its axis of rotation While permitting free movement of the other of said supports, and means for rotating said damper about the axis of rotation of the fixed support.

. 5. An air register of circular cross-section comprising a peripheral cylindrical wall being formed with a plurality v of openings, a plurality of circumferentially spaced dampers being constructed and arranged to close said openings when in their closed position, means for supporting each damper including a pair of pivotal supports affording diiferent axes of rotation for said damper, means for selectively securing one of said supports so that it rotates substantially only about its axis of rotation while permitting free movement of the other of said supports, and means for rotating said damper about the axis of rotation of the fixed support.

6. An air register of circular cross-section comprising a plurality of circumferentially spaced dampers, means for supporting each damper including a pair of pivotal supports at opposite ends of said damper affording different axes of rotation for said damper, means cooperating between adjacent dampers for selectively securing one of said supports so that it rotates substantially only about its axis of rotation while permitting free movement of the other of said supports, and means for rotating said damper about the axis of rotation of the fixed support.

7. An air register of circular cross-section comprising a plurality of circumferentially spaced dampers, means for supporting each damper including a pair of pivotal supports at opposite ends of said damper aifording different axes of rotation for said damper, rotatable retaining means cooperating between adjacent dampers for selectively securing one of said supports on One of said adjacent dampers so that said one of said supports rotates substantially only about its axis of rotation while permitting free movement of the other of said supports on the other of said adjacent dampers, and means for rotating said dampers about their respective axes of rotation of the fixed supports.

8. An air register of circular cross-section comprising a plurality of circumferentially arranged dampers, means for supporting each damper including a pair of pivotal supports affording different axes of rotation for said dampers, means for selectively securing one of said supports so that it rotates substantially only about its axis of rotation While permitting free movement of the other of said supports, and means connected to the central portions of each of said dampers for rotating said dampers about their respective axes of rotation of the fixed supports.

9. An air register of circular cross-section having a central axis comprising a peripheral cylindrical Wall formed with a plurality of spaced rectangular openings, a plurality of circumferentially spaced rectangular dampers being constructed and arranged on the inner side of said Wall to close said openings when in their closed position, means for supporting each damper including a pair of pivotal supports, said pivotal supports being disposed at opposite ends of said damper parallel to said central axis, means cooperating between adjacent dampers for selectively securing one of said supports so that it rotates substantially only about its axis of rotation while permitting free movement of the other of said supports, and means for rotating all of said dampers about their respective axes of rotation of the fixed supports.

19. An air register of circular cross-section having a central axis comprising a peripheral cylindrical wall formed with a plurality of spaced rectangular openings, a

a? plurality of circumferentially spaced rectangular dampers having a curvature substantially conforming to the curvature of said Wall and being constructed and arranged on the inner side of said Wall to close said openings When in their closed position, means for supporting each damper including a pair of pivotal supports disposed at opposite ends of said damper parallel to said central axis, rotatable retaining means cooperating between adjacent dampers for selectively securing one of said supports on one of said adjacent dampers so that said one of said supports rotates substantially only about its axis of rotation While permitting free movement of the other of said supports on the other of said adjacent dampers, and means connected to the central portions of each of said dampers for rotating said dampers about their respective axes of rotation of the fixed supports.

References Cited by the Examiner UNITED STATES PATENTS JAMES W. WESTHAVER, Primary Examiner. MEYER PERLIN, Examiner.

Claims

1. AN AIR REGISTER OF CIRCULAR CROSS-SECTION COMPRISING A PLURALITY OF CIRCUMFERENTIALLY ARRANGED DAMPERS, MEANS FOR SUPPORTING EACH DAMPER INCLUDING A PAIR OF PIVOTAL SUPPORTS AFFORDING DIFFERENT AXES OF ROTATION FOR SAID DAMPER, A MEANS FOR SELECTIVELY SECURING ONE OF SAID SUPPORTS SO THAT IT ROTATES SUBSTANTIALLY ONLY ABOUT ITS AXIS OF ROTATION WHILE PERMITTING FREE MOVEMENT OF THE OTHER OF SAID SUPPORTS, AND MEANS FOR ROTATING SAID DAMPER ABOUT THE AXIS OF ROTATION OF THE FIXED SUPPORT.