US1618905A - Smoke damper - Google Patents

Description

Patented Feb. 22,1927.

um; :s or Banam- Uma/ann mmsronnn, or 13mm; Gamm?.

SHORE DAHPEB..

Appnauon 1aed Apru 1s, 192s, serial ab. 101,760, ma 1a cermnyapru as, ma

order .that the stack draft maybe a le to,`

suck in atmospheric air directly instead o f from. the heated fluesl ofthe boiler. Since however withA the known construction this air inlet' passage has an immediate communication with the boiler and its lues it was unavoidable that on account of the buoyancy 2o of the hot air within the boiler atmo heric cold vairv wasA4 also sucked through t e air inlet passage into the hot boiler, whereby the purpose of the arrangement was practically' rendered illusory.

In order to do away with thisdraw-back we provide accordin to thisv present inyvention within'. the

:boiler tothe vstack and by means -of a sec- -ond additional damper av special' se arate space or compartment between the rboiler andthe stack, which space or compartment has a leakage connection with the stack andis ladapted to communicate with the outer atmosphere, care being taken, that no bypass communication, such as for example a Adirect leakage connection past the dampers and at the exclusion of `a said space orcompartment, may exist between the stack and l the boiler sides of the smoke `lue. As av result of such arrangement-a pressure equal or substantially equal to atmospheric pres- 'surc is produced between the smoke dampers constituting the said space or compartment, whereby an escape of heat from the boiler furnace or the like is successfully prevented, as will be described more in detail hereinafter. i 'In thedrawings illustrating some embodiments vof our inventionv l Fig. 1 illustrates the general arrange- Fig. 3 is a Stnal view of a modiiication ue leading from the ment according tof our invention in connec.

of the compound dxmper taken along 4line C-D Fig.5, v .'1'

.,Fig. 4 is a vertical cross section along line E-F Fig. 3,

- Fig. 5 1s a plan view of vthe modication 60 3, partly in section along line A-B 1g.'3. According to Fig. 1 of thedrawing'the combustion gases ofbboiler 1 pass as usual through a lue 2 .to the `stack 3, a shutting- 65 olf member, in this'particular instance, an ordinary smoke damper 4, being arranged within flue 2 between the boiler and the stack. Between' the damper 4 and the stack 3 We arrange according to our present inven- 70 tion a secondslide` or damper 5 thus permitting to :shut-oil orseparate from flue 2 a closedv separate' space or compartment 6,

`when both slides or dampers 4, 5 are in their lowered or operative position as shown in Fig. 1.A The space or compartment 6 is adapted to communicate with the outer atmosphere by .means of an orifice or passage 19 being controlledby an air inlet or valve mechanism 7. This'me'chanism comprises a 80 seating member 8 having a peripheralgroove A or channel 9 adaptedto receive a dlp-bell or valve member 10. The channel 9 is filled withloos'e dry sand or fine-grained lead'- shot, the inner edge 11 of member 10 being 85 so bevelled as to urge the sand or the like towards the inner face of channel 9. Thev bell 10'is guided by a'bracket 12 (Fig. 2) and attached to a Vcable 14 passing over sheaves 13 and having at its end a counter- 90 weight 15 with which a tappet 16 is adaptedto engage. This tappet -16 is attached to the rope or -cable 17 .carrying the shde or damper 5- and having at its outer end a counter-weight 18, as show n. The tappet 16 is so attached to cable 17 thatit enga es weight 15 only and thereby lifts the va ve member Yfrom its seat, when the damper 5 is nearly closed. vAir is thus automatically admitted to the s ace or compartment 6 100 whenever the two ampers are moved lnto their lowered or o erative position. i Y

` In order' that t e operation of ourimproved damper arrangement-sc far descrlbed may be readily understood 1t should be 105 borne in mind that the two slides or dempers 4 and 5 are moving in their guldes with a certain amount o unavoidable leakage. If

both dampers 4 and 5.are in their o rative 4position as shown in Fig. 1 the 3 has 110 communication withthe space 6`through the leakage of damper 5 so that it can suck i 0H cold atmospheric air entering through passage 19. The stack 3 has however no 5 direct/leakage or by-pass connection at the exclusion of or around the space 6 with that part of Hue 2 which is located between the slide or damper 4 and the boiler l so that I no heat can be carried 0H past such by-pass l0 l5 from space 6 and throughthe leakage be-n tween damper 4 and its guide into the boiler 1, so thatthe samewill retain substantially all of'the heat stored up in ait, with the u only exception of the slight 'heat losses by 1 radiation 2during the stand-still periods. Practical tests lhave shown that the total loss of heat occurring between two running periods can thus be considerablyreduced. In` many instances `the available space does damper 5 at such a distance from damper f4 that thev air inlet mechanism shown iny Fi s. 1 and 2 can be arranged betweenboth Vsli es or dampers. Also the operating mechanism for the air inlet device may be annoying since it will frequently have to be arranged in the passages of the boiler house. In-order to do away with this inconvenience and to facilitate the mounting of the installation we yconstruct accordingto Figs. 3, 4 and 5 a multiple, or compound Cdamper mechanism having a plurality of guiding ledges, so that one guide or pair of guides pertains to one damper or slide respectively. This compound damper mechanism is guided for vertical movementin a damper guiding frame interposed in the Hue between the boiler or furnace and stack and again constitutes a separate space or compartment adapted to communicate withfthe outer atin osphere by means of an air inlet mechamsm, when being in its lowered or operative pos1tion,.care being `again taken that ino Aleakage by-pass communication can exist be'- ,tweenlthe stack side andthe boiler sideyof Hue 2 around the space or compartment between the two slides or dampers.

f The ,arrangement of two groups of guiding ledges, one group for each sllde member 0,5. grooves or Channels 2l and 22 wpemting not permit to arrange the second slide ,or'

lor damper, is therefore of importance, since i (Fig. 4). The'two plates 26, 27 and their 70 connecting members 23 are thus constituting as a unitary self-contained structure a compound hollow smoke damper being at its upper end closed by Haps 29. In the lowered position of this compound damperEiFig.

3) the Haps are automatically opene by pushrods 30 loosely lsliding in bearings 31,

whereby atmospheric air is admitted to the hollow space. between the two plates 26 and 27 and can slowly be sucked 0H' to the stack 80 through vthe leakage between the guiding ledges `of the stack-adjacent damper plate and its guiding channels of frame 20, the.s operation being'thus exactly the same as that of the embodiment Figs. 1 and 2 at 85 which both Slides or dampers may be independently operated. Upon the damperbe- "ing lifted bv means off'lifting rod 32 and a suitable kind of hoisting mechanism the rods 30 will slide down and permit the Haps 29 90 to close.

-The compound damper as such must of course be well calked against the outer air. To this end the lframef20 `is at its upper end provided with/two transverse pocket-shaped beams 33 supporting rollers 34 'which by their gravity always contact with the plates 26 and 27, whereby the gap is bridged which must always exist between the lmasonwork or the4 damperA frame 20 and 100 the damper. The members 23 mustfhow-` ever also be calked against 'the outer air between the guiding ledges 24 and 25 in order to prevent an air entrance into Hue 2 while the boiler and the stack are in their 105 normal operation. Wve therefore provide in the members 23 channels35 adapted to receive one roller 36 respectively carried in chambers 37 of the damper guiding frame 20 and which are by Jgravity always held lin airtight contact with the members`23,

lugs 38' being provided on the guiding frame 20 'and extending into the channels 35 for the support of the rollers 36. In

order that the objectionable direct or bypass connection (between the stack side and the boiler side'of the Hue may be avoided we provide a communication of the space between the damper plates 426, 27, the cross wall 39 of the gn e walls of frame 20 with the space between the damper plates 26 a'11d27 and the cross tall 39 by arranging air passages 40 in the lower ends of the vwalls 39. Accordingly the stack draft can again not act past the ledges 24 which may for example be on the' VboilerV sideof Hue 2 on the air within the boiler side of Hue 2 and within the boiler Hues.

By the arrangement of the vspace or colic- 13 embers\23 and the cross 120 CFI partment adapted to communicate by leakage with the stack and to communicate by a valve mechanism with the outer air the stack draft can only suck oft air from this space or compartment through the sufiiciently large air inlet orifice and there always eX- ists within this space or compartment a slight vacuum which is a little below atmospheric pressure.` Accordingly and in the absence of any direct or by-pass leakage connection between the stack side and the boiler side of the fine' around the space or compartment no heat can be carried off by flowing air from the boiler lues into the stack; what will be discharged may eventually be the small gas quantities resulting from the belated burningr down of some suspended fine coke particles.

What we claim as our invention is:

1. A smoke damper apparatus for interrupting 'the smoke flue communication between a stack andl a fire place comprising a smoke flue, a plurality of flue obstructing slides adapted to establish in the smoke flue a separate compartment so that any by-pass communication between thel stack and thcl tire placeand at the excluli'lliof the said compartment is prevented, and means for admitting air into the said compartment.

2. A smoke damper apparatus for interrupting the smoke {lue communication between a stack and a lire lace comprising a smoke flue, a plurality F movable dainpers adapted to establish, when in Vtheir one operative positionin the smoke flue, a separate compartment havingleakage communication with the stack side and with the tire place side of the smoke .flue at the exclusion of any direct leakage connection between both smoke flue sides past the said compartment, and automatic means for admitting air into the said compartment when. the dampers are in their compartment establishing positions.

3. A compound dam er comprising a pair of rigidly connecte (distanced damper plates movable into and out of operative positioi,guiding means therefor adapted to Y constitute part of a smokeflue and permitting leakageconnection of the space intermediate t-he damper plates-with the adjoining ilue portions while preventing any direct connection of the said flue ortions at the exclusion of such interme iate space and means for admitting air into the space intermediate the damper plates.

A com ound dam er comprising a pair of rigi y c onnect distanced damper plates movabe into and ,out of operative position and adapted to separate from a smoke flue a closed compartment when being in the one operative position, a guiding frame having lateral walls ada )ted to be in substantial alignment with adyoiningwalls 'of a smoke flue and permitting in their cooperationwith the damper plates aleakage connection of the space intermediate the damper plates with/the outside of the saidl plates and at the exclusion of any direct bypass connection of t-he said outsides past the said intermediate space, covers closing the space between the two damper plates and means for,` automatically opening the said covers and for admitting air into the said intermediate space when the two damper plates are in their operative position.

5. A compound Vdamper comprising a pair of rigidly connected distanced damper plates movable between an operative and an inoperative position, aA guiding frame adapted tov constitute part of'a smoke flue and so ceo-operating with the lsaid damper plate that a leakage connection of yflue ends adjoining the guiding frame with the space intermediate the said damper plates is permitted while any direct byfpass connection cf the adjoining 'flue endsat the exclusion of sucli intermediate space is prevented, covers closing the space .intermediate the said damper plates and automatic means adapted to lift the cover plates and admit air into the said intermediate space, when the damper plates are in their operative position and to elose'the cover plates and cut out the air admission, when the damper plates arexbeing moved' into their inoperative position.

6. A-compound damper plate comprising a pair of rigidly connected distanced damper plates, a guiding frame therefor `adapted' to provide leaka e connection between the space interm iate the said plates and the and its guiding means and means for establishing a. permanent communication between the space 'intermediate the damper plates and the spaces intermediate the transverse walls and the guiding frame.

vspace outside the said guide and damper plates, transverse walls for connecting the. said damper plates and being arranged at` In testimony whereof we affix our signatures.

FELIX BAENTSCH. ALFRED sToBER.

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