US1517629A - Steam boiler and furnace therefor - Google Patents

Description

Dec. 1924 D. S. JACOBUS STEAM BOILER AND FURNACE THEREFOR Original Filed July 2, 1 1a Original application files July 2, me, Serial No.

To all whom it may concern:

Be it known that 1, DAVID S. tlnooiros, e citizen of the United filtetes, residing in Jersey City, in the county of ludson and State of New Jersey, have invented cert-sin new and useful Improvements in Steam Boilers and Furnaces Therefor, of which the following is a full, clear, and exact de scription, reference being had to the accompanying drawing, forming partof this specie fication, the drawing being a sectional side elevation of a horizontal water tube boiler constructed in accordance with my inyention.

The present application is a division of my application Serial No. 242,990, which was filed in the United States Patent Ofhce July- 2, 1918, Patent No. 1,470,744, Oct. 16, 1925, and relates particularly to furnace structure which co-operates with a boiler of the character described and claimed in the parent upplication.

' In the drawing, 2 represents an upper bank of horizontally inclined tubes, and 3 a corresponding lower bunk, shown as comprising three rows, the two banks of tubes preferably being separated a distance corresponding to the width of a plurality of rows. The front and rear furnace Walls are indicated by the reference numerals 4t) and 41, respectively, both walls being inclined outwardly on both their inner and outer faces, and the inner wall being inclined from a point adjacent the Stoker ledge plates,

y W to r in nor;

3, will. iiier'ial swo fitl.

extends over the upper rou or tube the headers 8 for a portion of h from the inner end of this heme ticel beflleezctends upwerdly, being for u s S from it between the rows along sulr-stuntielly the'entire length of the lowermost tubes.

The steam from the steam and Water drum 14 passes through pipe 15 to the header l2, thence through the ll-tubes to the hesder 152- whence it lows through nipples into heeder 12", and thence through the longer li-tu'oes to the upper header 12, where it is taken off. The gases rise from the furnace through the lower group of tubes, pass up to the left of the battles until they rise through the upper group or tubes, and then flow down tl'zroug h the upper group of tubes and out between the nipples 9 to the offteke flue 16,

In my prior application, above referred to, is shown ov two-stage economizer comprising a high-pressure stage and a low-pressure stage. in my presmt application, the louthe furnace lining preferably being" substanpressure s age ison itted and a portion only tially all of refractory material. The front of the higli-gn'essure stage of the economicer wall is supported by a nimnber 450, the rear is shown at A, the waste gases ,from the wall 41 being provided with an opening; il boiler flowing downwardly over, the highuffording access to the sticker and through pressure ste s. The, economizcr construe which a tool may be lYzSQlQQtl to remove the clinker which collects over the stoke-r dump platesw The combustion clnnber at, below the lower set of tubes, extends substantially the entire length of the tubes and is of a 3:1 chamber shown, wiere the hopper-shaped construction, with the undered through combustion. flow feed Stoker 5 at the narrow part of the ogri'essivei increasing in hopper, the front of the undertteed Stoker 5 rough the furnace from the coming under the uptake headers 6. boiler tubes and contact with w The lower ends of the upper bani; of iully the full length of the lowerwuter tubes enter e group oi? headers '2', while the'lower ends of the lower tubes 3 enter headers 8, these headers 7 and 8 being connected by longspeced-apart nipples S). A. ballle 10, disposed at the rear of the boiler,

, that the are made to f. go up; the lowermost boiler tubes in 2 sonahly uniform way throughout their is tn, thusdistributing the heat from one.

till

ut oi the tubes and avoiding local intensification of action at certain points through a torch-like effect of the flames. After distributing the gases by means of the special form of furnace, so that they contact with the entire length of the lowermost t-ubes,'the gases are directed forwardly by nism, and through the dumping plates, and

is pro ected rearwardly in thefurnace." The form of the tuyeres of the stoker, which admit thecompressed air, causes the air to be projected 'rearwardly, and when the rear portion of the fire becomes thin, or when a pqrtionof the fire is broken through by the action of the blast, the construction of the tuyeres is such as to project the air and gases rearward. It can be readily seen that where a stoker produces auaction of this I sort, the form of furnace is particularly woul adapted to give increasedefiiciency over an arrangement wherein the excess air and gases, projected to the rear of the furnace, d pass directly upward along the rear wallof the furnace and enter the spaces between the. boiler tubes without being mingled with the combustible gases in the in terior of the furnace.

Building the front andrear walls of the setting so as to make them incline outward1y,as shown, the front wall being in v clined from a point adiiceiitgthe stoke'r ledge plates, is advanta'gnus,in= maintaining the brickwork, as the fweig'htof f the wall of itself holds the walls in alignment and prevents the walls from bulging inwardly. This element is important: in connection with the high capacities at-which boilers and furnaces are now beiu .foperated.

It is especially desirab eflin connection with underfeed stokers of tie type shown, where the action ofthe-ferced blastoften causes difliculties through erosion of the front walls. Again, in burning certain coals, clinkers may form inthe fire pit, and the top of the fire pit may also cake or become encrusted so as to cause the forced blast to project torch-like flames'against the front wall. Inclining the front wall outward at the top, in the way shown, is, therefore, especially advantageous where stokers of the forced blast, underfeed type are employed. Inclining the front wall outward, in the way described, necessitates its being supported in .part by the outer member or 1 members arranged to come in front of the r It is especially advantageous in the case of an underfeed stoker, to set the Stoker further beneath the boiler than in ordinary practice, and to incline the front well outwardly in the way described, as, in addition to increasing the mingling effect of the gases and thereby promoting combustion, the era sion of the front wall through the action of the hot gases, which is oharaderistic of this type of stoker, will be minimized or eliminated. The erosion referred to comes through the impinging action of the hot gases and through the swirling or vortex action of the gases produced through the effect of the forced blast which enters through the tuyres near the front of the furnace and the form of the fuel bed resulting from the underfeed method of supplying the coal, which causes the depth of t is fuel bed to be greater a short distance from the front wall than it is directly against and near the front wall. With a vertical front wall, the combustion conditions may be such as to cause a lane of flame and unconsumed gases to pass upwardly along the wall and into the spaces between the boiler tubes before the gases are consumed in the furnace, and, at the same time, there may be difiiculty through the erosion of the inner face of the wall through the impinging action of the hot gases, or thro h the swirling or vortex action. By inclining the front wall outwardly, the difficulties referred to are minimized or entirely overcome. Under the same conditions, the use of a vertical front wall would lead to a lane of flame hugging the wall, while the use of an inclined front wall of the character illustrated herein, 'r'would cause the flame to be spread out and broken up through eddy currents before it reached the tubes, with a resulting increase in the amount of combustible ases burned within the furnace chamber. 53y reducing the swirling and vortex action of through the use of an inclined wall, where the face of the wall will be a greater distance from the point from which the hot gases are projected from the fuel bed than with a vertical wall, the amount of erosion will be greatly decreased over that which would exist with a vertical wall. Inclining the rear wall outwardly also increases the mingling efl'ect of the gases in the case of underfeed stokers, so that the form of furnace described is particularly adaptable to underfeed stokers. These same advantages areembodied in the form of furnace shown in my application Serial No. 302,728, filed June 9, 1919. In the furnace shown and described in connection with the latter application, the front wall of the furnace extends vertically a short distance above the stoker edge plates and then inclines outwardly, the vertical portion of the wall being protected by the.cr0ss box shown in'the front furnace The arrangement is particularly usefulv where particles of fuel or of ash containing combustible matter are thrown upwardly in the furnace, as is the case with a forced blast underfeed stoker or other types of forced blast stokers, or where any other method of burning coal is used where such particles are carried upwardly by the products of combustion, as the widening effect of the top of the furnace reduces thev velocity of the gases, which, in turn, reduces the speed at which the particles are traveling and causes them to remain in suspension a longertime within the furnace, or to spread out and to be whirled in eddies within the furnace, or to fall along the sides of the furnace to the bottom of the furnace. This action gives a longer time for the particles to burn within the furnace and increases the efficiency of combustion. The burning out of the particles Within the furnace, combined with the large flow area between the boiler tubes at the bottom of the first pass, reduces the slag ging difficulty, so that, inaddition to securing a higher efficiency, the combination gives better operating results.

Furthermore, the described furnace con struction permits the use of access doors in the inclined wall for afurnace in which practically the entire length-of the lower. most tubes are exposed to the radiant heat bed were close to the water tubes, and hence till close to the gas outlet, there would. be no chance for the gases to mingle thoroughly and be completely burned before reaching the tubes. Applicant prefers to make the furnace chamber high enough so that the gases will be thoroughly mingled and sub stantially burned before striking the relatively cold Water tubes. This increased height of the furnace introduces a new factor-viz, the swirling or vortex action of the gases which causes erosion of the front wall. To overcome this difficulty and, at the same time, have a relatively high combustion chamber, applicant uniformly in clines the front wall and supports it by a member located in front thereof, thereby, at the same time, minimising the tendency to erosion and overcon'iing the tendency of the wall to fall inwardly should erosion. take place. Furthermore, inclining the front wall, and preferably also the rear wall to produce a hopper shaped furnace, in. itself serves to increase the minglin eliect of the in to gases and helps to bring about the complete burning thereof before reaching the boiler tubes.

By providing the inclined rear wall with an openingadjacent to the dumping bars, it is possible for the operator to stand nearer the dumping bars in moving the clinker than would be the cas 1 h a vertical wall built up to the ends of 1 tubes. Tl

ne com-- bination, therefore, to provide an elli- 'cient arrangement forgetting at the clinker where a Stoker or other 4 ate is set in a position with reference to the boiler similar to that shown in the drawinas.

While l have herein shmvn. and described one embodiment of my invention, l do not desire to be limited tot e exact arrangement shown and described, but seek to cover, in the appended claims, all those modifications which come within the true spirit and scope of my invention.

W hat I claim and desire to secure by Let tors Patent of the United States is:

1. In combinatioi'i, a fu nace having an unobstructed upwardly increasing flow area,

water tubes disposed above the furnace 'crr- I tending in a horizontally inclined direction, the lowermost of the tubes being crroosed to the furnace chamber throughoutsubstantially their entire lengt d sa d chamber being sufficient in to permit substantially complete ccinbue of'the before reaching said tube", horizontally inclined baffle disposed above certain of the tubes, and means for directing the in decreasing flow in the first pass across the tubes. 2. In combination, a furnace having its front and rear fl 1 upwardly and cutwardly inclined to or .n u. unobstructed. upwardly increasi j. chamber, wate tubes nace extending it her? rection, the lower posed'to the fin substantially the furnace chamber permit substantially co; the gases before reachin zontally inclined hafiie al of the tubes, and in gases in a decreasing now a pass across the tubes.

3. In combination. front and rear said tubes, a hori' sposed above certain directing the sea in the first nace having its out ,a in the furnacewardly inclined on both their inner and outer faces to form an unobstructed upwardly increasing flow area in the furnace chamber, water tubes disposed abovethe furnace extending in a horizontally inclined direction, the lowermost of the tubes being exposed to the furnace chamber throughout substantially their. entire length and said furnace chamber being suflicient in height to permit substantially complete combustion of the gases before reaching said tubes, a horizontally inclined bafiie disposed above certain of the tubes, and means for directing the gases in a decreasing. flow area in the first pass across the tubes.

4. In combination, a forced blast underfeed stoker, the furnace walls forming a hopper-shaped furnace, parallel inclined boiler tubes located above said furnace and comprising at least two banks of tubes spaced apart, a roof baflie located above the lower bank, the tubes of the lower bank being exposed for substantially their entire length, and means comprising a bafiie extending upwardly from the end of said roof bat'fle across the tubes, forming a progressively decreasing fiow area for the gases.

5.In combination, a furnace having an unobstructed upwardly enlarging furnace tubes,-

chamber, horizontally inclined water tubes comprising two spaced banks located above the furnace chamber, the lowermost tubes being directly exposed forsubstantially their c. entire length to the radiant heat of the furnace, 'said furnace chamber being sufliciently high to permit approximately complete combustion of the gases before reaching said a roof baflle located above certain of the tubes and extending longitudinally .f-thereof, and means defining a constricted first passacross the tubes through which the gases flow, said means including said baflie located above certain of the tubes.

6. In combination, a furnace having an unobstructed upwardly enlarging furnace chamber, horizontally inclined water tubes comprising two spaced banks located above the furnace chamber, the lowermost tubes being directly exposed for substantially their entire length to the radiant heat of the furnace, said furnace chamber being sufliciently high to permit approximately complete combustion of the gases before reaching said tubes, a baflie located above certain of the tubes and extending parallel thereto, means defining a constricted first pass across the tubes through which the gases flow, said means including said bafile located above certain of the tubes, and a superheater located between the two said spaced banks of tubes.

7. In combination, a furnace having an unobstructed upwardly enlarging fuirnac-e chamber, .fuel feeding mechanism for the fur nace which causes heated particles to be car ried upwardly through the furnace chamber, substantially parallel horizontally inclined water tubes comprising two spaced banks located above the furnace chamber and spaced. apart a distance. corresponding to the width of a plurality of rows, the lowermost tubes being directly exposed for substantially their entire length to the radiant heat or the furnace, said furnace chamber being sufficiently high to permit approximately complete combustion of the gases before reaching the boiler tubes, a baflie located above certain of the tubes and extending parallel thereto, and means defining a constricted first pass across the tubes through which the gases flow, said means including said ballle located above certain of the tubes.

DAVID S. JACOBUS.

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