US2638892A - Furnace damper control - Google Patents

Description

y 9, 1953 D. v. HAMMOND ETAL 2,638,892

FURNACE DAMPER CONTROL Filed Dec. 22, 1947 5 SheetsSheet l INVENTORS D.V. HAMMOND T. R. SHAW BY 7 90.2LLER May 19, 1953 Filed D60. 22, 1947 D. V. HAMMOND ET AL FURNACE DAMPER CONTROL FIG.

O 0 (I) @IEI O C 5 Sheets-Sheet 2 INVENTORS D.V. HAMMOND T. R.SHAW

2 0.0. MILLER A T TORNEVS May 19, 1953 D. v. HAMMOND ETAL FURNACE DAMPER CONTROL 5 Sheets-Sheet 3 Filed Dec. 22, 1947 FIG. 4

INVENTORS .0.v. HAMMOND T. R. SHAW BY 0.0. MILLER ATTORNEYS May 19, 1953 Filed Dec. 22. 1947 D. V. HAMMOND ETAL FURNACE DAMPER CONTROL 5 Sheets-Sheet 4 5a 55 5|,52,53 A K is 6 FIG. 5 5

FIG. 6

ATTORNE S INVENTORS D.V. HAMMOND T. R. SHAW G.O. MILLER May 19, 1953 ,D. v. HAMMOND ETAL FURNACE DAMPER CONTROL F 'iled Dec. 22. 1947 5 Sheets-Shae; 5

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QOOQK V ROW lusk INVENTIORS o.v. HAMMOND 1-. R. SHAW G. O. MILLE R A T Tm m3 v v HASQQQEEE Patented May 19, 1953 FURNACE DAMPER CONTROL Dale V. Hammond, Pittsburg, 'Kans., and Thomas R. Shaw and Guy 0. Miller, Bartlesville, Okla., assignors to Phillips Petroleum Company, a corporation of Delaware Application December 22, 1947, Serial No. 793,238

4 Claims. (Cl. 126286) 1 This invention relates to furnaces. In one of its more specific aspects it relates to furnace dampers and in a still more specific aspect it relates to a control mechanism for the operation of furnace dampers.

An object of our invention is to furnish a control mechanism for the operation of furnace dampers. Another object of our invention is to provide an apparatus for the closing of furnace dampers. Still another object of our invention is to provide an apparatus for the closing of furnace dampers, which apparatus may be operated from a point remote from the furnace. Still another object of our invention is to provide a safety closure means for closing of furnace dampers, which means may be responsive to excessive temperature within the furnace.

These and other objects Will be realized upon reading the following disclosure and taken with the attached drawing, which respectively describes and illustrates a preferred embodiment of our invention.

In the drawing, Figure 1 represents diagrammatically the front elevation of a furnace burner and wind box equipped with the damperclosure apparatus of our invention. Figure 2 is a section view of the furnace dampers and air ducts. Figure 3 is a side elevation of the damper closure means. Figure 4 is a side elevation of the damper closure means on the side of the wind box opposite the elevation of Figure 3. Figure 5 is a plan view of a release lever bar. Figure 6 is a longitudinal sectional view of the release lever bar of Figure 5. Figure 7 is an elevational view of the control box and toggle joint apparatus. Figure 8 is a side elevation, partly in section, of a furnace assembly showing sidewalls, roof, temperature indication means and remote damper control apparatus.

Referring to Figure 1, thewind box proper is composed of a front wall I l in the center of which is a burner l2 positioned in a burner opening 13. The furnace front wall contains a wind box [4 which may best be seen in section in Figure 2. This wind box it is equipped with an upper damper l5 and a lower damper I6. wall is also equipped with a fire box damper l9. This latter damper controls air flowing through a duct BI directly into the fire box of the furnace. A duct 82 permits the flow of a small quantity of air into the fire box of the furnace at all times.

The upper damper I5 is rigidly attached to a damper shaft I1 and the damper rotates around this shaft as a center. In like manner, the

damper i6 is attached to a dampershaft H3,

The front shaft l1.

around which the damper rotates. Also the damper I9 is attached to and rotates around a damper shaft 20. The damper I5 is intended to control the flow of air from the exterior of the furnace into the upper portion of the wind box M. This damper extends across approximately the entire front wall of the wind box. The dampers I6 and 19 also extend across the entire front Wall of the wind box, dampers l6 controlling the flow of air into the lower portion of the wind box I4 and damper l9 controlling the flow of air into the air duct 8|. Air from the wind box [4 passes through a series of openings 24 into the area adjacent the burner for passage into the fire box.

On one end of the upper damper shaft I1 is rigidly attached a weight 2|. This Weight may be positioned on the shaft I! at any desired angle from the horizontal. This weight is intended to close the damper I5 upon release of a holding mechanism on the other end of the damper shaft.

A damper weight 22 is attached to one end of the lower damper shaft l8. This weight is also adjustable with respect to the horizontal and is intended to rotate the damper shaft I8 to close the damper I6 upon release of mechanism at the opposite end of this shaft.

In a like manner, a damper weight 23 is attached to the same corresponding end of the fire mechanism on the opposite end of the shaft 20. The holding mechanism for the upper damper l5 may be seen in Figures 1 and 3. In Figures 1 and 3 a wheel 3| is rigidly attached to the end of the This wheel has a handle 32'attached thereto in such a manner that the wheel may be turned by hand, as in opening the upper damper IS. The shaft l8 also has attached to its end a wheel 33 with a handle 34. Shaft 20 has a similar wheel 35 with a handle 36.

Each of these wheels has some notches 54 cut into their peripheries in such a manner as to form teeth for meshing with a square bar 58 within the release lever assemblies 62, 63 and 64, one of which is shown in Figure 6. These levers are constructed of pairs of side bars 55, 56 and 5'|, between which is attached the handle members 5|, 52 or 53, respectively, for-the several release lever assemblies. A vertical support, member, as an angle iron 16, is attached to the side of the windbox by brace members 11, and is intended to support the pivot ends of the hand lever assemblies 62, B3, and 64. By this mean trip bar 54 in the wheel 35 and the operator can then by: grasping the handle 36 rotate the clamper and shaft, l9 and 23, respectively, to any position desired. The weight 23 on the Bride this da riper shaft 28 is intended to besog-positio, w thwler'.

spect to the shaft 2!; that when .the weight :is approximately horizontal the damper IE will be closed. Then upon rotation..ofthehar dle 35 in, the proper direction the weight 23 is lifted and the damper it is opened to whatever extent is 151 sired. positi-en downward pressure is .released from the handle Bland the compressiomspring' 48 r ises thalever assembly 52., so that the square barjfi meshes -;with a notch in the wheeljfi tp; held the wheeltif position and the damper -j 9 op en. $13 l er w nd h s dems i m ybe s t q l n kermae e tsu hi s o nw rd on the handle 52. which compresses tri s rmeie andiallow-s rotationiof the hand vvheel st and re st n Q ib am e l new i a mssss is-t en e as dir m t e hand e il 'nd the-leve arm t3 raises-to .hold;the wheel 33 irrits-.position. The compression springrlii is heldin placeby a bolt fill andaiplate member All which latter member is .attached. rigid1y. .to .thevtrip bar 3,1.

i The upper. Wind box; damper- .15, maybead- .iilstdina manner sim ilar .to the otherdampers m lusbin r r i emand press spring 553,, Whe el 3Listher radiust a m the s ared spinn r. ninmnd thee th as sseshan e 5- slse d.. allQW the lev r assemb y. 1 -4- to r e s ihs t e numbe 5 .1, I s1i$ w th sc ch 55 n i s Y Wh e ie hel t e. damp r is t PIPP eei 'sm- Th 99, 21.- P'i s m sp eens s mis 99 i messi h member 47, the latter being attached rigidly to th i is bani?- Tsei y ar i1. car esei as a'n'ieans to make certain that upon operaposer a control assembly H; the trip bar will i y When the several dampers are in their respectiveoperating positions, that is, partly or fully open; the lower end of the trip bar 3'! is intended to be aninch .or'twoabove a base plate 4% positioned at the bottomv linewof the furnace. and direotlyunder the trip bar. .With the trip-bar raisedthe control assembly ll is in the position as 'i-ndicated inlthe drawing ;This control assembly .I I. is-vcomposed of several parts, a controlboX 2.3:which containsla: control,

apparatus and a toggle assemblyJZ; This. toggle assembly is composed of. two togglezmembers' 92 heldltos her y. a shaft. 951. The upp r end f h pper tosglemember 92;.is pivoted, to ahar When the damper i9 is in this opened The toggle apparatus and its operation may best be seen upon reference to Figure 7 of the drawing. As shown in Figure 3 and in Figure 7 the toggle member is so positioned that the trip bar 31 is an inch or two above the base plate 44. It will be noted that the toggle member 22 are out of-';1i1i,e wi-th;respeet top; straight line joining the :pivot' shafts 96 and -91. The lower toggle shaft 92 rests against a stop washer Hi2 which in turn is locked in place by lock nut I ill on a bolt l qlli 'l'his bolt stop assembly 98 is attached to a support member 99 which in turn is supported ,byzlthe channel support member 15. The supportmember 98 may be attached to the channel-by welding-or other means as desired. The

' stop-nut IBZ'is intended to act in preventing the 9 which n rn is idly-att che toz hetrip lQWBrtoggle member 92 from resting too far off center to the left (Figure 7) so that upon a slight movement of a toggle arm member 94 to the right (in Figure 7) the two toggle members 92 will; at; their :common .point (sl' aftv 90.) move towardithe center. .lineconnecting pivots $6 and-1951 and: beyond this .c.enter-1ine.toward the right. When the armmember QLso operates the toggle members 92, the upper end of the upper; tog le membenfiz, its shaft 9 6, the bar 91 and the trip bar -3 1 dropsuntilthe trip. bars! rests. onithe base plate 44. When the trip bar SLdrops in this manner the plate members 45, t6, and 4] drop also and these of course lower thecompression springs -48, 49 and-5i) to permit dropping of the' release levers 52;, 63 and 64 to release-the notched wheels 35; 33 and Zil thereby permitting the weights 23, 22 and 21 to drop and to close theseveral darmoers;

To-reset the trip bar toggle mechanism it is merely necessary to-push the toggle arm member Qil and the shaft 98 (eommon point of the toggle members-92) to the left, as in Figure '7, to such an extent that the shaft or pin -is beyond before explained. I

g The angiron members 4I,' 42 and 1130f Figures 1 :3 are attached to the side wallof the wind box for the support of bearings through which theseveral damper shafts extend. The fweight ends of the damper shafts are also positioned in bearings to facilitate rotation of sh v The control box; toggle assembly of Figure 7 con ists two main parts, the toggle assembly 13 and the control box 73. rh'e control box," maybe-constructed of steel plate lined with heat n ulat ng. li es m te a ill Wi n t 56X s esqleneiq. wn e i ise meta as I '6- T is eismi -1. 2, n i ac-Qnvs i onaice i i armature, orarm, liq a-pi ted rou d a shaft I l 5 .in. ,such manner that uponclosingthe circult ,inlead wires 1 M the arm H5, will be drawn to the qore ll 3,and.he1d in that position ,until thepircu itin wires H5. isbroken] Theshaftlfi aroundwhioh vthe.armature H5, rotates extends through the, sidewall of the box lea-n01 outside theflhox. this shaft is rigidly fastened to. a bar znemher 1211...,The other. end of this bar memlglLis pivoted -.to one end-of thetoggle arm emb r: in 119 a man h t w e th armature. .llfi rotat es tothe right and is ,held

my tripped to the right and the trip be" 31 falls, thereby permitting all three dampers of the wind box to close.

This solenoid may be operated or made responsive to any operation as desired, for example, as illustrated in Figure'l, the diagrammatically illustrated box H8 may be a conventional controller unit, with wires H9 leading to a thermocouple l25. The thermocouple may be installed at any desired location in the furnace fire box and this apparatus so operates that-When the temperature in the fire box rises to a value above the maximum permissible fire box temperature the control apparatus H8 will operate to close the circuit H4 which will cause the core H3 of the solenoid to become magnetized. The core will then attract the arm I I6 and the toggle joint will be tripped and the trip bar will be dropped to permit automatic closing of thedampers.

Then when the temperature in the fire box drops below the referred to maximum temperature the circuit I Hi will be broken and the armature released from the core H3 but the toggle joint will not move to reset itself because of the heavy weight of the trip bar 3'! and its weighting member 38. This operation must be done manually. The control box H8 receives current from a source not shown through power lines l2l."

The lead wires H9 which'have hereinbefore been mentioned as attached to a thermocouple positioned in a strategic location may be attached to a push button in the control house in which the furnace operator spends a portion of his time. With the push button apparatus, incase of a fire or other emergency, the operatormay close the dampers of the furnace by merely pushing the button to close the circuit in lines H9 and in H 4 which in turn will cause the rapid closing of the dampers.

Referring to Figure 2 this burner front wall assembly is actually the front wall of the furnace with the wind box and burner in place. The insulation material 83 is the front wall of the fire box while the exterior or right hand portion of this figure represents the outer surfaces of the front wall of the furnace and the furnace wind box. The upper damper permits the inflow of air from the atmosphere through the upper portion of this front wall through an opening made when the damper is open. The lower wind box damper l6 and air duct 82 receive atmospheric air through an opening 85! which extends horizontally across the entire front of the wind box. The air duct 8| receives its air when the damper I9 is open through a front wall opening 19 which opening starts substantially at the ground level and extends laterally across the entire front wall of the wind box.

We have found that the damper closure mechanism as herein disclosed operates very satisfactorily as a safety device for furnace operators in case of an emergency. The device further assists in minimizing furnace damage in case of a fire by rapidly permitting either automatic or manual closing of the furnace dampers.

Materials of construction of all of the apparatus parts may be selected from those commercially available and no special alloy steels nor special materials are required.

We have herein described a preferred embodiment of our invention but it will be obvious to those skilled in the art that the construction or operation of various apparatus parts may be varied and yet remain within the intended spirit and scope of our invention.

Having disclosed our invention, we claim:

11 A damper operating device comprising, in

combin'ation,- a damper disposed in a gas carrying conduit and mounted on a shaft, said damper being nonrotatable with respect to said shaft, both ends of said shaft extending beyond the confines of said conduit, a weighted damper closing means at one end of said shaft and outside of said conduit for constantly biasing said damper toward a closed position, a sprocket wheel on the other end of said damper shaft, a hand lever pivoted atone end to a fixed support for vertical movement'with respect to said sprocket wheel, a sprocket tooth attached to said hand lever in such a manner as to mesh between teeth of said sprocket wheel when the other end of said hand lever is in a raised position and to disengage from the teeth of said sprocket wheel when said other end of the lever is in a lowered position, a compression spring for biasing said other end of said hand lever toward said raised position, a vertically disposed weighted shaft, means for guiding said vertical shaft for vertical reciprocating movement only, means attached to said vertically disposed weighted shaft and engaging said lever to biasjsa'id compression spring upwardly in a compressed condition when said vertically disposed shaft is positioned at the upward end of its extent of longitudinal movement, and a toggle assembly for holding said vertically disposed shaft at the upper end of its extent of longitudi'nal movement, said toggle assembly comprising a first and lower fixed pivot, a first generally upright disposed toggle arm member rotatably fixed at its lower'end to said first pivot, a second generally upright disposed togglearm member pivoted at its lower end to the upper end of said first arm -j member at a second and generally horizontally movable pivot point, the upper end of said second toggle arm member being pivoted to said vertically disposed weighted shaft, aforesaid pivot points being disposed substantially in a straight line when said vertically disposed weighted shaft is at the upper end of its extent of longitudinal movement, stop means to prevent movement of said second pivot point in one horizontal direction from its substantially centered position, means to move said second pivot point from said centered position in the opposite horizontal direction whereupon said vertically disposed weighted shaft moves downward by force of gravity to release the bias of said compression spring to unmesh said sprocket tooth from said sprocket wheel and said damper will return to its closed position under the influence of its bias, and a manually operable means for rotating said damper shaft to open said damper against its bias.

2. A furnace assembly for heating material comprising, in combination, a fire box surrounded by side walls and a roof, a burner assembly disposed in one side wall, a furnace windbox surrounding said burner and communicating therewith for conducting air from the exterior of the furnace to the burner assembly, said windbox having an opening for admitting air thereto, a damper assembly extending into said windbox for controlling the flow of air comprising, in combination, a damper disposed in said windboX in controlling relation to said opening and mounted on a shaft, said damper being nonrotatable with respect to said shaft, both ends of said shaft extending beyond the confines of said windbox, a weighted damper closing means at one end of said shaft and outside of said windbox for constantly biasing said damper toward a closed posiaeemea '2 tion; a: sprocket:v wheel O H 5fih&aa0th9l'1 i da-of said dam er-wa t;- ha d lever i edet one n to-a fixed suppont,--forz vertioalu movement -,With respect: to said i sproclget wheel, a,--spr9G-ket tooth attached to saidhand lever in such a manner asito mesh: between qteethof, said-sprocket wheel when the-pthen endwoi said hand lever is :in-a raised'position and to disengage from thewteeth of said. sprocket wheelwhen said other end'of the layeris-in a. lowered: position; r a compression springcfor biasing-said other end iOf said hand lfiYBlptOHfiId-fiflid raised position a vertically dis T isted weighted shaft; means for guiding; said verticalzshaft' for vertical reciprocatinghmove: mentonly, meansattached to said wer-tieally; disposed weighted shaft andengaging,said levenv to bias-said-.compressien springiupwardly in :a com.- pnessed condition when? saidflvertically disposed shaft is positionedahthe upwardvend of itsextent Qtlongitudinalmovement, andla toggle: assembly for -holding said vertically ldisposed shaft at-the uppenendpi l-itsextentoi longitudinal; movement,

saidntoggle assembly-comprising-a first and lower fixed; pivot, .afi-rstgenerally, upright disposed toggle arm l member \rotatably fix d: at its a lower l end= tOff-Sfiid, first, pivot, ,asecond gener lly run: rightdisposed togglelarm member (pivotedsat-its low-erl-endto the'uppenend-of said firstarm member at a; second and generally horizontally movable ll'ivotpoint, theuppertend of =said.-se,c ond togglelarm member: being. .pivotedato u said verti: callyx disposed, weighted. shaft, aforesaid pivot points being: disposed s11bstantiallyin; a straight line when said .venticallyadisposed; weighted shaft a t the upper endrof its extent iofllongitudinal movement; stop means to; preyent: movement of a e second ivot oi t-ineneh ieental imetion from its substantially centered I position, means 0imq ide cq dr e pointifromseid centered positionin theoppositehorizontal direction-whereupon -said vertically disposed weighted shaft: moves; downward by force of gravityv to releasez'the :bias oiv Said compression spring-to unmesh said. sprocket tooth from said sprocket wheelaand said-"damper will return to its closed positionmnder the influence of its bias, and a manually operablemeans for rotating said dampeashafttoopen said-damper against its bias. Thelf-urnacei assemblyuof claim 2 wherein saidmeans to' -m ove -saidsecondxpivot point com- Vp gises an electrically operable means responsive to temperatures within the furnace.

14a The furnace. assembly ofclairn 2 wherein said means ;to move said second pivot point .comprises-Lian electricallypperable means. operable froma point remote-from said furnace Y DALEV. HAMMOND. THOMAS Rh, SHAW. GUY ,O. MILLER.

Referencesones inthe file. of this patent UNITED STATES PATENTS Number Name 7 Date- 812149 Dunn Feb. 17, 1885 422,956 Malmborg Mar. 11, 1890 1,0L8,659 Claus; a- Dec. 31, 1912 1-,L25A1-6, Watsoni Jan, 19, 191 5 l',352,2 55,l Emerson Sept. '7; 1920 11,627,013 Cowie-- May 3, 1927 1 2,190,892 Swepston E'el o. 20, 1940 3. 38 H r burt N v- 0, 9.4 $339,614. Breese- Jan. 18, 1944

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