US2515701A - Adjustable baffle arrangement for use with steam generating boilers - Google Patents

Description

July 18, 1950 R P DE VRIES 2,515,701

ADJUSTABLE BAFF'LE'ARRANGEMENT FOR USE WITH STEAM GENERATING BOILERS Filed Dec. 5, 1947 v 2 Sheets-Sheet 1 IyENTOR. .lfezqzez'jzze J'z'es,

BY I E 2 {27a W July 18, 1950 R. P. DE VRIES I ADJUSTABLE BAFFLE ARRANGEMENT FOR USE WITH STEAM GENERATING BOILERS E2 Sheets-Sheet 2 Filed Dec. 5, 1947 Patented July 18, 1950 UNITED STATES PATENT OFFICE ADJUSTABLE BAFFLE ARRANGEMENT FOR USE WITH STEAM GENERATING BOILERS Rainier P. De Vries, Melrose, Mass.

Application December 5, 1947, Serial No. 789,995

6 Claims.

This invention relates to improvements in steam generating boilers of the water tube type.

Steam generating boilers of the water tube type, as heretofore constructed, are usually provided, in association with a bank of water tubes thereof, with an arrangement of baffles or partitions so designed and placed as to direct the movement of hot gases of combustion, from the firebox of the boiler, through the water tube bank whereby to cause said gases to flow in contact with the water tube surfaces substantially throughout the lengths of the tubes before discharging through the boiler stack. The provision of such baiiles or partitions is neither satisfactory or efficient, not only because they are costly to install and replace, but, in use, tend to trap and collect fly ash, so that masses of such ash pile up on portions of the baffles or partitions and accumulate around and cover portions of the water tubes, with the consequence that both free flow of the hot gases to the boiler stack is impeded, and contact of said hot gases with the covered portions of the tubes is blocked, with resultant loss of tube heating surface and drop in tube efiiciency.

Having in mind the above cited and other objections to the use of gasfiow directing baflles or partitions in association with a bank of tubes in a water tube type boiler, it is an object of this invention to provide a novel construction and arrangement of adjustable means which is located. above and entirely separate from the bank of tubes in a water tube type boiler, and which is adapted, when properly adjusted, to so influence the draft induced flow of hot gases of combustion from the boiler fire box upwardly through the bank of tubes, and ultimately to the boiler stack, that substantially uniform contact of the hot gases with the entire surface area of the tubes throughout the lengths thereof is assured with substantially uniform heat transfer to said tubes. The invention having for a further object to provide a gas flow directing and controlling means of the character mentioned which avoids draft obstruction of spaces intermediate the water tubes by accumulations of flyash therein; and which avoids accumulation of fly ash in covering relation to tube surfaces with heat transfer limiting eifect.

Other objects of this invention, not at this time more particularly enumerated, will be understood from the following detailed description of the same.

An illustrative embodiment of this invention is shown in the accompanying drawings, in which:

Fig. 1 is a fragmentary longitudinal vertical sectional view of a steam generating boiler of the water tube type which is equipped with the novel means for directing and controlling draft induced flow of hot gases of combustion from the boiler fire box through the bank of boiler water tubes in accordance with the purposes and principles of this invention; Fig. 2 is a transverse vertical sectional view of the same, taken on line 2-2 in Fig. 1; and Fig. 3 is a fragmentary horizontal sectional view of the same, taken on line 3- -3 in Fig. 2.

Fig. 4 is a fragmentary detail longitudinal sectional view, somewhat enlarged, taken through a portion of the gas flow directing and controlling means; and Fig. 5 is a fragmentary transverse vertical sectional view of the same, taken on line 5-5 in Fig. 4.

Similar characters of reference are employed in the above described views,to indicate corre-- sponding parts.

Referringto the drawings, the reference characters H] and M respectively indicate the front and back walls of the housing of a steam generating boiler, the side walls of which are indicated by the reference character I 2. Suitably supported at the top of the boiler housing are one or more steam collecting drums or domes I3, preferably disposed to bridge the front and back walls of said housing. Leading outwardly from the upper interior of the boiler housing, as e. g. through the front wall II] as shown, adjacently beneath the steam collecting drums or domes I3, is a smoke pipe or other suitable conduit M which extends to the boiler stack or chimney not shown). Within and across said smoke pipe or conduit 14 is pivotally mounted a draft control damper [5, which may be and usually is automatically actuated in suitable manner, asalready well known to the art.

- Located within and across the upper interior of the boiler housing, beneath the steam collecting drums or domes I3, is a bank [6 of spaced water tubes, the tubes of which incline upwardly through the housing interior from front to back thereof, The tubes of the bank l6 thereof are conencted by their lower ends to and in communication with a forward manifold H, the latter being, in turn, connected byiping IS with the'forward end portions of the steam collecting drums or domes l3; and, similarly, said, tubes are connected by their upper ends to and in communication with a rearward manifold l9 which, in turn, is connected by piping '20 with the rearward and por ions of t e steam collecting drums or domes I3. The water tubes of the bank l may be cleaned through the blow down line 2| which is connected to and in communication with the lower end of the forward manifold Any well known means (not shown) may be used to supply boiler feed water. The above described arrangement and setting of the bank of water tubes is one most commonly used, but, as will be understood, may be varied, if desired, to suit other design of boilers of the water tube type, so long as the setting and arrangement admits of installation of the hereinafter described novel means for directing and controlling draft induced flow of hot gases of combustion from the boiler fire box upwardly through the spaces intermediate the tubes.

The means for directing and controlling draft induced flow of hot gases from the broiler fire box upwardly through the spaces intermediate the water tubes of the bank H5 is disposed within the upper interior of the boiler housing above said bank "5 of water tubes and beneath the steam collecting drums or domes l3, and comprises a ceiling member or plate 25 of a width to extend'across the housing interior from one to the other of the side walls thereof, and from the back wall forwardly to a point adjacent to the front wall I0. Said ceiling member or plate 25 is preferably positioned to incline somewhat downwardly from said back wall toward the front wall ID of the boiler housing. The ceiling member or plate 25, as thus disposed, subdivides the upper interior of the boiler housing so as to form a water tube bank containing chamber 26 below the same, and a gas collecting chamber 2'! above the same and beneath the steam collecting drums or domes l3. Said gas collecting chamber 21, thus provided above the ceiling member or plate 25, communicates directly with the intake end of the smoke-pipe or conduit I4 through which the gases of combustion are discharged to a boiler stack or chimney by the draft effect of the latter. If required, an auxiliary ceiling partition 28 is provided to extend between the forward end of the ceiling member or plate 25 and the front wall In of the boiler housing, at a point of the latter below the level of the intake of said smoke-pipe or conduit I4,

thus assuring the sealing off of the outlet end of the gas-collecting chamber 21 from the water tube bank containing chamber 26, whereby to prevent flow of gases from the latter to the smoke-pipe or conduit I4 in by-passing relation to the gas collecting chamber 21.

. The ceiling member orplate'25 can be sup- :-ported in its above described operative position within the boiler housing interior in any conven- ;-ient manner; -preferably,-however, the same is suspended by hanger bolts 29 which depend from ber or plate 25- is provided with a plurality of longitudinally extending, laterally spaced apart slots or ports 3|, which extend from front to back of theboiler housing interior, andin direction corresponding to the direction of extension of the water tubes contained in the bank I6 to the rearward end portion thereof.

thereof. The ceiling member or plate 25 is preferably reenforced against warping by upstanding longitudinally and laterally extending ribs 32 and 33 which are integral therewith, certain of which bound the margins of said slots or fiues 3| (see Fig. 3).

Movably supported upon the ceiling member or plate 25 are a plurality of cover or damper plates 34 which respectively cooperate with the respective slots or ports 3| of said ceiling member or plate, and which can be slidably shifted relative to said slots or ports 3| so as to form operative open areas of the latter which taper from the rearward ends toward the forward ends thereof, whereby to offer variable resistance to gas flow through the slots or ports along the lengths thereof and into the gas chamber 21. By thus shaping the effective open areas of the slots or ports 3|, maximum resistance to gas flow therethrough occurs at the ends of the slots or ports nearest to the point of draft induced discharge of gases through the smoke pipe or conduit M, where the draft suction is of maximum effect, which resistance gradually diminishes along the slots or ports toward the ends of the latter which are at greatest distance from said point of draft induced discharge of the gases through the smoke-pipe or conduit M, and where the draft suction is of minimum effect. In this manner upward flow of the hot gases of combustion, rising from the boiler fire box, as induced by draft suction through the gas collecting chamber 21, is substanially equalized from front to back of the bank l6 of water tubes. and consequently contact of said gases and transfer of heat therefrom to the water tubes of the bank i6 is substantially uniformly applied to the water tubes throughout the lengths thereof, so that necessity for the use of gas flow directing bafiies or partitions in association with said bank l6 of water tubes, and the objectionable consequences attendant upon the use of such bafiles or partitions, hereinabove referred to, are

, avoided.

Means are provided for adjustably shifting and determining desired positions of said cover or damper plates 34 relative to the slots 01' ports 3|, whereby to taper or shape the effective open areas of the latter. To this end. each cover or damper plate 34 is provided with an u standing medial flange or web 35 which extends longitudinally therealong from the forward end portion These flanges or webs 35 not only stiffen and reenforce the cover or damper plates against warping and distortion, but also provide means for coupling -manipulatable shifting and adjusting devices thereto. The shifting and adjusting devices are engaged with opposite end portions of said flanges or webs 35, and are common to corresponding end portions thereof. Said shifting and adjusting devices comprise a forward shift rod 36 which is provided with screw-threaded opposite end por- -through and so as to project exteriorly of op- .posite side walls l2 of the boiler housing, with tions 3! and 38 respectively slidably extended the body of said shift rod extending transversely across the forward end portions of the cover or damper plates 34, and a rearward shift rod 39 'also provided with screw-threaded opposite end portions 40 and 4| which are likewise respectively slidably extended through and exteriorly of opposite side walls [2 of the boiler housing, with the body portion of this shift rod extending transagar-moi versely acrossv the "rearward end portions 'of the cover or damper plates 3 4,}fsaidshiftfrods :35 and 39 extend through slots lzw'ith wh-idh the end portions of theflang'e's'br webs35 of the cover or damper plates 34 are-provided. es the shift rods 36 and 39, adjacent tofopposite 'si'deso'f the flanges or webs 35 of the "cover or damper plates through which'they pass, are collars 43 which, by abutment upon flanges or web portions, function to translate axial mdvements of the shift rods into lateralfshi'fting movements of the cover or damper platest t. Screwed onto the respective screw-threaded opposite emportions 3'5 and 38 of the forward shift rod 35, which project exteriorly from the 'respectii fe side walls 52 of the boiler housing, arethfe respective lock nut sets M and'45; and, similarly, screwed ohto the respective screw-threaded opposite end portions Ml and l of the rearward shift rod '39, whikih likewise project exteriorly from the respective side walls 12 of the boiler housing-are therespective lock nut sets 45 and 41. i M

It will be understood that the firebox'of the boiler is located, as indicated by the reference character 5'9, in the lower int'erior portion of the boiler housing beneath thebahk i 6 of water tubes. so that the hot gases'o-f combustion, generated in the fire-box by combustion of suitable fuel, will rise so as to passfthroughthe spacesjbetween the water tubescontained in the bank I 6 thereof.

As is well known the upward flow er gases of combustion is induced by the draft uptake by which said gases are discharged through the boiler smoke-pipe and stack. Since the intake of the smoke-pipe is usuallythrough a wall of "the boiler housing, and since the suction effect of the draft is at its maximumm those portions of the boiler housing interior which are adjacent to said intake, the'gase's', as infiuencedbyjdraft suction, tend to flow at highest velocity through the path of least resistance and most di 'rectto, the smokepipe intake. For'this reason, unless otherwise prevented, the gases, althoughef'fic'iently contacting those portions arms-bani; of water tubes which are nearest to the smoke pipe intake, will tend to lay-pass or makejinefficient heat transfer contact with the portions of the bank or water tubes which are remoteffroin the smoke-pipe intake. To avoid such unequal heat transfer contact of hot, gases with thejbank of watertubes ,it has, in the past, beenbustom'ary top-rovide ,bafiies and partitions so disposedgiri associationwith and in relation to the bank of water tubes, that the gases are first, compelled't'o contactremote portions of the water tubes and thereafter portions of the latter which :are more closely adjacent to the smoke-pipe intake. The objections to the useof such bafiies and partitions has been already above referred to. v

By the present invention, the "necessity for use of baffles or partitions within the bank of;water tubes has been avoided by..,the,provisionpf;the ceiling member or plate 25. having theflongi-tudinal slots or ports 3! and the. adjustable eover -,-or damper plates 34 cooperative with the latter, and as interposed between the draft influenced gas collecting chamber 21, through which draft induced suction is effected, and the water tube bank containing chamber 26 through which initial up flow of gases of combustion occurs.

In use, the cover or damper plates 34 are so adjusted relative to the slots or ports 3! as to narrow the latter at points nearest the smokepipe intake, and thence gradually Widen the same toward the points most remote from said smokepipe intake. In this way, restrictive-resistance 'to up-fiow of gases-in the zoneo'f maximum draft suction is set up, which resistance is gradually reduced toward the zone of minimum draft suction. As a consequence of this, the draft suction effects are substantially equalized throughout the cross-sectional area of that portion of the boiler housing interior which provides the water tube bank-containing chamber '26, and consequently the up-flow of gases through the water tube bank is substantially uniformin volume and velocity fromend to end of the latter.

The cover or damper plates 3d may be adjusted by manipulation of "the shaft rods 36 and 39. For example, the lock nut sets his and 11 being loosened, by turning home the opposite lock nut sets M- and d6 against the adjacent side wall l'2,the shift rods may be drawn to the right (as viewed in Fig. 3) respectively for difierent distanoes or amounts, whereby toobliquely offset the cover or damper plates 551i relative tothe slots or ports 3!, in such manner thatthe desiredtapered open areas of said slots or ports '31 'are formed. The amount of relative adjustment of the opposite ends or the "cover or damper plates, which may be required in'any given case, can be determined by taking thermometer readings at opposite ends of a slct'or port 31, and then manipulating the cover 'or damper plates until the compared readings are of substantially thesam'edegree.

After the cover or damper plates 3d have been desirably adjustedgthe same and the shift rods may be secured against accidental displacement by tightening the loosened lock nut sets 45 and. 41. It will, of course, be obvious that the cover or damper plates 34 may optionally be adjusted either to the right or left.

Having now described my invention, I claim:

1. A steam generating boiler provided by a housing having a fire-box in its lower interior, a bank of water tubes within the fire-box, a celli-ng member above the water tubes to provide a chamber in the upper interior of the housing, said ceiling member having ports in' the form of elongated slots through whichgases of combustion pass from the fire-box upwardly into said chamber, a draft inducing means communicating with an end of the chamber through side wall ,of the housing whereby to' discharge *saidgases from the chamber, said port forming "si'ots erotending lengthwise" in direction substantially parallel "to the direction of outward flow of gases from the chamber to and through the draft in- 55 ducin'g means, damper plates' 'cooperative with andexte'n'ding longitudinally of the'port formducing means "so as to set upmaximum resistance to upward'g'as fiow through the re port forming slots atpoints subjectto maximum suction eifect "of the draft inducing means with diminishing resistance toward points of decreasing suction effect ofthedraft"induciri'g means. f

2. A steam generating boiler as defined in claim 1 wherein the means for adjusting the damper plates comprises the provision, in con nection with opposite end portions of each damper plate, of an upstanding flange having a slotted opening therethrough, shift rods common to the damper plates respectively extendthereof, collars afiixed on said shift rods in straddling relation to the flanges of each damper plate, opposite end portions of the shift rods respectively extending slidably through and exteriorly of opposite side walls of the housing, and manipulatable nut means threaded onto the exterior end portions of said shift rods, said shift rods being individually axially movable to laterally shift the damper plates relative to the port forming slots for passage tapering effect.

3. A steam generating boiler provided by a housing having a fire-box in its lower interior, a bank of water tubes within the fire-box, a ceiling member above the water tube to provide a chamber in the upper interior of the housing, said ceiling member having parts in the form of elongated slots through which gases of combustion pass from the fire-box upwardly into said chamber, a draft inducing means communicating with an end of the chamber through a side wall of the housing whereby to discharge said gases from the chamber, said port forming slots extending lengthwise in direction substantially parallel to the direction of outward flow of gases from the chamber to and through the draft inducing means, laterally shiftable damper plates cooperative with and extending longitudinally of the port forming slots, mean to pivot the end portions of said damper plates which are disposed adjacent to the discharge end of the cham ber and the draft inducing means, and means cooperative with the opposite end portions of the damper plates for laterally adjusting said damper plates relative to the port forming slots, whereby to taper the latter toward the draft inducing means so as to set up maximum resistance to upward gas flow through the port forming slots at points subject to maximum suction effect of the draft inducing means with diminishing resistance toward points of decreasing suction effect of the draft inducing means.

4. A steam generating boiler as defined in claim 3 wherein the means for positioning the damper plates comprises the provision, in connection with opposite end portions of each damper plate, of an upstanding flange having a slotted opening therethrough, shift rods common to the damper plates respectively extending across their corresponding end portions through the slotted op nings of the flanges thereof, collars afllxed on said shift rods in straddling relation to! the flanges of each damper plate, opposite end portions of the shift rods respectively slidahlv extending through and exteriorly of opposite side walls of the housing, and manipulatable' nut means threaded onto the exterior end portions of said shift rods, the shift rod cooperative with the ends of the damper plate which lie adjacent to the discharge end of the chamber and the draft inducing means being manipulatable to determine pivoting points for said ends of the damper plates, and the other shift rod being axiallv movable to laterally shift opposite ends of the damper plates relative to the port forming slots for passage tapering effect.

5. A steam generating boiler provided by a housing having a fire-box in its lower interior and a steam collecting means at its top, a bank of water tubes within the fire-box, a ceiling member extending across the interior of the housing above said bank of water tubes whereby to provide a, chamber beneath said steam collecting means, said ceiling member having gas ports in the form of elongated slots through which gases of combustion from the fire-box, after traversing the bank of water tubes, pass upwardly into said chamber, a draft inducing means communicating with an end of the chamber through a side wall of the housing whereby to discharge gases from the chamber, said gas ports extending lengthwise in direction substantially parallel to in direction of outward flow of gases through the chamber to and through the draft inducing means, damper plates respectively longitudinally coextensive with said respective gas ports, and respective means cooperative with opposite end portions of the damper plates manipulatable to shift the latter to diagonally disposed relation to the gas ports 50 as to taper the effective gas passage area of said ports toward the draft inducing means, whereby to set up maximum resistance to upward gas flow through the ports at points subject to maximum suction effect of the draft inducing means with diminishing resistance toward points of decreasing suction effect of said draft inducing means.

6. A steam generating boiler as defined in claim 5 wherein the means for positioning the damper plates comprises the provision, in connection with opposite end portions of each damper plate, of an upstanding flange having a slotted opening therethrough, shift rods common to the damper plates respectively extending across their corresponding end portions through the slotted openings of the flanges thereof, collars affixed on said shift rods in straddling relation to the flanges of each damper plate, opposite end portions of the shift rods respectively slidably extending through and exteriorly of opposite side walls of the housing, and manipulatable nut means threaded onto the exterior end portions .of said shift rods, the shift rod cooperative with the end of the damper plate which lie adjacent to the discharge end of the chamber and the draft inducing means being manipulatable to determine pivoting points for said ends of the damper plates, and the other shift rod being axially movable to laterally shift opposite ends of the damper plates relative to the gas "ports for passage tapering effect. a

- REINIER. P. DE VRlES.

REFERENCES CITED The following references are of record in the file of this patent:

STATES PATENTS Number Name Date 683,758 Hering Oct. 1, 1901 713,185 Webster. Nov. 11, 1902 1,708,654 Andrews Apr. 9, 1929

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