US1884524A - Furnace - Google Patents

Description

Oct. 25, 1932. H. H. BAUMVGARTNER 1,884,524

FURNACE Filed April 25, 1929 2 Sheets-Sheet 1 I N VEN TOR.

BY WWW-3 H Saw/MW WNW-:4 awwg A TTORNEYS.

Oct. 25, 1932. H. H. BAUMGARTNER FURNACE Filed April 25, 1929 2 Sheets-Sheet 2 A TTORNEYS.

stoker, or with hand vfired furn Patented L 25, 1932 warren STATES PArsiar GFFICE HENRY HON ELL BAUMGARTNER, OF BELLEVILLE, NEW JERSEY, ASSIGNOR TO DRAKE NON-CLINKERING FURNACE BLCCK COMPANY, INC., OF NEVI YORK, N. Y., A COR- PORATION OF NEW YORK Application filed April 25,

wall useful therewith. The general features relating to combustion method and furnace are applicable more especially to the classof furnace having a grate carrying a fuel bed, particularly stoker fired furnaces, for example of the underfeed, multiple retort type, although useful also on the chain grate typ eiplf e special feature of an air cooled wall structure is applicable to furnaces of the class referred to or other classes, such as furnaces burning pulverized, liquid or gaseous fuel. A typical ll example of an underfeed multiple retort stoker fired furnace is that shown in the Warren C. Drake Patent 1,i00,036 patented December 13, 1921; while a typical instance of an air cooled furnacewall is that shown in my prior application SerialNo. 135,925 filed Sept. 16, 1926. 7

One of the general objectsof the present invention is to bring about the rapid and complete combustion of the volatile gases isr. .L. suing irom the greenfuel introduced at the front portion of the fuel bed in a grate furnace, herein illustrated as an .underfeed multiple retort type of furnace. A particular ob,- ject is to secure such complete and rapid com bustion of the volatiles through the use of highly preheated secondary air, this being preferably introduced through the front, wall of the furnace and injected at a downward slant and with such force as to penetrate and thoroughly break up the ascending stream of volatiles, thus ensuring, not merely the thorough mixture and contact with the secondary air, but by the high preheating thereof,

the'rapidcombustion of the volatiles.

A further object of the invention is to provide an effective construction of hollow wall, preferably of refractory elements, with interior air circulation adapted not merely to maintaining the w all cool, as against destructive overheating, but to provide for high preheating of combustion air. Such preheated air may be used by injection at the front wall, fort-he purposes already set forth, or in some cases may advantageously be introduced at 11 the side or bridge walls of the combustion FURNACE 1929. Serial No. 357,997.

chamber. A particular object is to provide such an air cooled refractory wall as will be exceedingly strong and durable in use while presenting ample channels for air flow both horizontally and vertically so as to sweep the interior of all portions or, the wall subject to exposure to high heat. a

Other and further objects of the present in vention will be pointed out in the hereinafter following description of an illustrative embodiment thereof or will be apparent to those conversant with the subject. To the attainment of such objects and advantages the present inventionconsists in the novel combustion method and furnace, ,and the novel air cooled wall, and the novel features of opera-. tion, arrangement, combination. and con structiomherein illustrated or described. I

In the accompanying drawings Fig. 1 is a view corresponding to Fig. 1 of said Drake i patent, and may be considered as a vertical section taken ina fore-and-aft direction, for example on the line 11 of Fig. 2, through one of the retorts of an underfeed'furnace, with many parts therefore shown in left elevation. i a

.Fig. 2 is a transverse section looking from the rear and taken for example on the line 22 of Fig. 1. a

Fig. 3 is a perspective View showing the interior construction andarrangement of the elements of the air cooled wall hereof.

- Figs. 4 and 5 are detached perspective views of the two principal structural elements of the wall,.designated respectively as U-blocks and T-blocks on account of the approximatecontour thereof when seen in top view.

Fig. 6 is a detail cross section taken on the horizontal line 6- 6 of Fig. 2.

Fig. 7 is a detail perspective view showing a partial assembly of certain of the wall elements.

Fig. 1 shows many of the general and well understood parts of a furnace of the underfeed, multiple retort type. Thus the combustion chamber is shown as bounded by the front wall 8, side walls 9 andbridge wall 10. At the front is shown the fuel hopper 11 delivering fuel by rams into the retorts 12, each ram being enclosed in a box 13- and operated by mechanism enclosed in a drive box 14 through a crank shaft 15 actuated from a drive shaft 16 common to all of the rains.

Within the combustion chamber are shown systems of twyers 18 bridging the spaces between the retorts. Each row of twyers is set at a downward incline so that the fuel bed travels progressively toward the rear under the usual agitating principle; and the fuel passes from the twyers and retorts on to an overfeed or extension grate 19 and thence to a dumping grate 20 by which the burned out fuel or ashes may be intermittently discharged into an ash pit beneath. There is shown a main air duct 22 supplying airunder forced draft to any number of furnaces. Each furnace has a connecting dnct'23 leading from the main duct to a transverse air box 24 which supplies the air to the longitudinal air boxes 25 located between the retorts 12 and beneath the twyers 16.

'Above the combustion space is shown a portion of a typical water tube boiler 27, between the tubes of which extends a bafile 28 to compel the hot gaseous products of combustion to traverse in the usual manner the several sections of the boiler.

The parts thus far described by reference numbers may be of any well known or approved construction except insofar as the same are modified in accordance with the features hereinbelow described. Various details of the furnace are herein omitted from the drawings or description because understood to those skilled in the subject and because forming no part of the novel features of the present invention.

The side walls 9, the front wall 8 and preferably also the bridge wall 10 of the combustion chamber are herein shown as built up of a special structure and arrangement 0 wall blocks or members, of refractory character, to produce interior wall passages for the circulation of air under the princiles of this invention. Thus at the zone of i hest temperature adjacent to theedges o thefuel bed, are shown special wall members or :blocks 30 and constituting wall fa'cings, these being spaced away from the outer solid wall portions to afford the interior assages referred to.

' ile other types of wall structure might be used in connection with the general features of the invention the preferable structure is as shown wherein the blocks 30 and 40 have the special forms as separately illustrated in Figs. 4 and 5 respectively. The blocks 30, commercially known as U-blocks,

each consist of the body portion of generally rectangular form and a pair of preferably vertical lugs 31 at the interior side, in part projecting across the wall air space, but

shaped to accommodate the spacing bricks 49 to be referred to and to leave recesses for the flow of air transversely to the plane of the lugs. Each lug 31, at its furthest inward point, has an end 32 abutting against the outer wall, also a top shoulder or ledge 33 supporting one end of the spacing brick.

The lug moreover instead of being rectangular is cut away at 34 so as to leave a recess for the flow of air in a horizontal direction, as plainly seen in Figs. 3 and 7, or at right angles to the vertical flow between each pair of lugs. In addition to the lugs each wall member 30 has at the top or bottom, preferably the top, a rib or tongue 35 and opposite'to it a groove 36 adapted to receive a similar rib at the under side.

The rib 35 at the top edge of the blocks 30 is shown as abbreviated, for a special purpose, which may be accomplished by knocking oil part of each rib, if not molded in such form.

Cooperating with the U-blocks 30 are the T-blocks 40. Each of these comprises the body portion and a lug 41, in this case not at each edge of the block, but at an intermediate point or g oints, preferably central, as best shown in igs. 3 and 5. The T-block lugs 41 may be of twice the width of the U- block lugs 31 inasmuch as two of the latter will stand side by side in the built up wall as seen in Fig. 3. Each lug 41 has an abutting end 42 likethe end 32 of the U-block, also a top ledge 43 and a cutaway portion 44. Also each T-block has along its upper edge a rib 45 corresponding with a groove 46 along its lower edge. Each lug 41 is also specially formed with an underneath recess 47 to receive one of the tie members 52 to be referred to.

While these cooperating U-blocks and T- blocks might be assembled in difierent ways, they are preferably assembled in tiers, substantially as shown, with one tier composed wholly of U-blocks 30 and the next tier of T- blocks 40, the individualblocks in the succes sive tiers being sta ered in the usual way of building up a we] and the tongues and grooves giving a very secure and strong engagement. Inasmuch as the contiguous lugs 31 are at the side edges of the U-blocks 30 while the lugs 41 are at the centers of the T- blocks 40, the staggered relation of the blocks brings the system of lugs in vertical alinement, as best seen in Fig. 3. This leaves a space between the under side of each lug or lug pair and the top ledge of the next lug or lug pair below, to receive and snugly accommodate one end of a spacing brick or tile 49, the outer end of which is embedded permanently in the masonry portion of the outer wall portion composed preferably of fire bricks 50. These spacing bricks therefore supplement the abutting contact of the lugs 31 and 41 with the outer wall and insure that the wall will retain its vertical condition as against deflection from the fire. Additional- 1y, each spacing or anchor brick 49 will be attached by friction or inserted wall cement to the lugs above and below and so hold the wall against deflection toward the fire; or

' upper side of one of the spacing bricks 4:9 and the overlying wall brick. The tie is shown also as having a T-shape inner end or head 54:

V the furnace as will be later described.

of half round shape so as to be accommodated in a portion of the groove 46 at the under side of each T-block 40, namely at the point where the cooperating ribs of the underlying U- block have been abbreviated as stated. The T-head 54 of the metal tie therefore is locked in the groove between the U-blocks and T- blocks, while its stem 52 is accommodated in the recessl? at the under side of the T-block lug 41, and its outer or flat head 58 is' locked within the masonry of the outer wall portion. These ties may be provided at desired intervals, for example between each T-block lug and the special brick beneath, and the large number of such tie pieces will effect a very strong union between the wall facing and outer wall to prevent distortion.

The described air cooled wall structure therefore is extremely strong against any distortion from changes of temperature or other factors. It is exceedingly durable. The face members may be composed of any high resistant refractory such as fire clay, silicon carbide or in some cases metal. The inner sides of the face members are constantly swept with streams of air traveling both vertically and horizontally through the hollow wall thus cooling the wall and superheating'the air.

The spaces within the several walls 10, 9 and 8 may be connected up in'series. Thus a connecting air passage 55 is shown leading from the duct 23 to the air spaces within the bridge wall 10. This forced draft air therefore is compelled to pass first through the bridge wall, in both directions, and the bridge wall passages are arranged to deliver into the side wall passages, so that the air travels next adjacent to the hottest portions of the side wall linings at the two sides, coolingand protecting the walls and absorbing heat. From the side wall air passages the air thence passes into the front wall air passages the two sides oftl e furnace. from which passages the highly preheated air is to be projected into In order to give a better distribution of the preheated air supply and pressure across the front wall the following baffle arangement maybe adopted. Asseen in Fig. 2 a baffle 56 extends from the side wall through the front wall air space at a level between the topmost horizontal air passage and the next passage beneath, in other words in horizontal alinement with the spacing bricks 49 directly below the topmost tier'of U-blocks. Similarly between the second and third horizontal air passages or tiers of blocks, is a second and longer interior baffle 5?. By this arrangement the air entering the front wall air spaces at the different levels is distributed so that some of it passes directly to the center of the front. wall and other portions to intermediate points, thus giving a fair distribution throughout the length of the front wall.

The preheated air, according to this invention, while it might be introduced at several or all of the walls, is preferably introduced only at the front wall and in a manner to give a forcible injection of the highly preheated secondary air in a manner to'impinge upon and thoroughly penetrate and breakup the volatile gases rising from the green coal. The fuel bed contour is approximately indicated by'the dotted line F. The path of the volatile gases rising from the green coal adjacent to' the throat is indicated approximately by the path lines V. The preferred injection or jets of preheated air is indicated'a-t A. Fig. 1 approximately or diagrammatically indicates these several factors of operation. It will be understood of course that the injected secondary air and the rising streams of vola-' tiles will combine and ascend by a path which i will be the resultant of the travelof the volatiles and air respec'tivel the diagram being intended to indicate howthe forcible jets of highly preheated air are arranged and adapted to break up and thoroughly penetrate the volatiles. The introduction of the jets of preheated air is preferably through special blocks 59 directly overlying the topmost tier of U-blocks 80 at the front wall, the blocks 59 presenting a series of nozzles 60,'which may be formed by registering grooves at the side faces of the adjacent blocks. The preferred arrangement and contour is bestillustrated in Fig. 1 where it is also seen that each nozzle 60 is supplied with preheated-air by a vertical channel 61 which in turn receives air from the air spaces or channels behind the topmost tier of l.l'bl0CkS 30. Above the several tiers of special facing blocks 30, 40 and 59 are suitable face tiles, bricks or blocks6 5 forming the body of each wall above the Zone of hi 'hest temperature.

The air travel through the several walls is extremely effective both for wall coolingand air preheating purposes. The effective cooling enables the wall face to be-made relatively thin, for example a" with safety, thus enhancing the wall cooling and air'preheating effect; the wall being at all times maintained below the softening pointof the refractory so as to preclude s ailing, slagging or adhering of clinkers. no to the integral lugs 31 and 41 at the back or interior side of the wall blocks there is a greater surface exposure to the air traversing the wall than there is to the fire, tlHE'PIDmOtiIIg the extraction and removal of absorbed radiant and other heat. If desired the wall may be composed of clay refractories such as kaolin at certain points, with silicon carbide blocks at any point subjetted t0 particularly high temperatures.

The very highly preheated air is injected directizinto the stream of rich gases distilled from preliminary or coking zone of the fuel bed, which in some casesmay be approximately one-sixth of the total length of the bed from front to rear. The nozzles are aced substantially higher than the peak of bed and may be even considerably higher than shown, and directed at a substantial downward slant so as effectively to intersect the rising gases rich in volatile matters. The numerous jets delivered by closely spaced nozzles are able to penetrate forcibly the stream of volatiles, intersecting and breaking them up so as to thoroughly mix the air and gases and prevent stratification of the latter.

The problem involved is to effect the combastion of the rich gases before their escape from the wmbustion chamber. This problem has not been satisfactorily solved by expedientshenetofore proposed. Highly rapid combastion is essential to completely utilize the carbon contents of the gases and this invention accomplishes this result through the combined high preheating of the secondary air and the forcible injecting of it into thorough mixing contact, so that excess oxy- 0 gem is present and brought into combining relation to all portions of the combustible contents of the gases. The arrangement of air injection at the front of the furnace in 7 theDrake patent is inadequate for the pur- 45 poses of the present invention. The air is not adequately preheated nor is it injected sufficiently forcibly to penetrate and thoroughly mix with the volatile gases throughout the zone, and the air apertures in the Drake patent are not advantageously arranged or directed for the purpose. The present invention is so highly effective in its complete combustion of the otherwise waste volatile gases, that the furnace can be op- 7 3-5 eluted with less secondary air and will deliver a greater quantity and proportion of CO, than in prior furnaces; and moreover the invention permits a furnaceto be operated at considerably higher temperatures.

The spacing brick 49 are well adapted to serve as anchors since the arrangement, as seen in F ig. 3, is adequate to effect a bond or tie between the outer Wall and the facing. In the process of erecting the wall the anchor at bricksAQ are confined between the lugs 31 and 41 and may be attachedby usual cementing means; so that no metal ties are necessary, the tie 52 being indicated as a possibly valuable supplement in certain special cases.

The several lugs 31 and 41 are shown as of substantially triangular form, so that the horizontal passages between the spacing or anchor bricks are substantially triangular. This arrangement is advantageous in providing adequate horizontal passages while givis ing a design of lug that is strong and unbreakable. The vertical passages or ducts between the alined lugs and anchor bricks are unrestricted. Vertical travel can be compelled at any point by providing a vertical HI baflle, namely simply by plugging or filling up the triangular openings beneath the anchor bricks in any given vertical series. On the other hand an effective horizontal baffle can be produced at any given level, for example the baffles 56 and 57, by replacing the anchor bricks 49 at such level by wider bricks or tiles 56 or 57 in endwise contact so as to close the vertical passages against air travel. At the corners where the air passes from the bridge wall to a side wall or. from the side Wall to the front wall special corner blocks are provided having a filleted surface facing the fire and interior spaces analogous to those already described. 90

The described air cooled wall is advantageous in that it is composed of shapes or blocks which are simple, inexpensive to manufacture and durable in handling and use. The wall composed of such blocks is of low installation 1 o cost as the blocks are easy to set up. The wall itself is durable and of loW maintenance expense. The structure is of flexible character, being adaptable to various and irregular existing conditions. The air flow passages are ample and present low resistance so that large quantities of air can be delivered at relatively high speed.

It will thus be seen that there has been described. a combustion method and furnace together with the structure of a wall adapted to be air cooled and to supply preheated air, the same embodying the principles and attaining the objects of the present invention. Since various matters of operation, arrange- 1' 1 ment, combination and construction may be modified in different ways without departing from the principles it is not intended to limit the invention to such matters except to the extent set forth in the appended claims.

What is claimed is:

1. A hollow furnace wall having an outer wall portion and an inner facing, the facing composed of special blocks of two shapes in 7 i 3 staggered assembly, the first shape being a rectangular block with internal vertical lugs at both edges, and the second shape being a rectangular block with an internal vertical lug at its middle, whereby all said lugs fall 3;;

in vertical ,alinement, to form vertical air passages, said lugs of such reduced area as to form horizontalcommunicating passages, separate means to space and anchor the facing with relation to the outer wall portion, comprising bricks projecting from the outer wall and engaging the lugs, and metal ties overlying such bricks and each having a T- shape head engaging grooves between the blocks, and a flat head engaging in the outer wall portion.

2. A hollow furnace wall having an outer wall portion and an inner facing, both built of refractory bricks, the facing comprising a number of bricks having internal lugs, and means to space and anchor the facing with relation to the outer wall portion, comprising a number of bricks projecting from the outer wall across the space into abutting contact with the wall facing, the lugs and bricks being in mutual engagement and vertical alinement to afford vertical air passages in the wall interior, and metal ties resting on top of such bricks, each having an inner head in embedded engagement with the wall facing, and an outer head in embedded engagement with the outer wall portion.

In testimony whereof, this specification has been duly signedby: HENRY HOWELL BAUMGARTNER.

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