US2016762A - Furnace - Google Patents

Description

C. B. 'YODER FURNACE Filed Jan. 17, 1925 di Sheets-Sheet l C. E. FURNACE @an m5.,

Filed Jan. 17, i925 i- Sheets-Sheer. 2

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FURNACE Filed Jan. 17, 1925 4 Sheets-Sheet 4 Patented Oct. 8, 1935 UNlTED STATES PATENT OFFICE' FURNACE tion of New York' Application January 17, 1925, Serial No. 3,100 6 claims. (ci. 122-4235) My invention relates to improvements in a furnace and the main object of the invention is to so construct a furnace that the expense of installation and operation of said furnace is reduced to the minimum. Heretofore the failure of fire brickwhen subjected to high temperature has been taken as a matter of course, another trouble of furnace operation to be borne, and an extra boiler or furnace frequently was provided to enable repairs to be made without delay when the brick lining had become burnt out.

The main function of a boiler is to generate or produce steam at the lowest. cost and in the operation utilize all possible heat and it is an object of my invention to provide a water or steam cooled furnace lining which allows a much higher temperature to be used without injury to the fire brick lining. This object is obtained by using a fire brick having an aperture therethrough and through which a boiler tube is extended, the tube being connected into the boiler circulation system so that instead of burning out the expensive fire brick I use the lining .as additional heating surface for the boiler. The tubes keep the walls in absolute alignment in any shape desired for the water or steam in the tubes keep the re brick cool and by so doing the heat carried away goes to the boiler in the form of steam, thus increasing the boiler efriciency.

A further object is to provide a construction that allows free expansion of both i'lre brick and the steel tubing. In the present method of laying up re brick where no provision is made for expension the fire brick frequently fails due to the severe compressive strains set up when the brick get hot and expand, said strains often stressing the boiler room build-ing frame work so that the steel becomes bent and dangerous. This objection is cvercome in my invention by having the brick loosely secured to the tubes whereby the tubes are permitted to slide inside of the brick lining o-r the brick slide on the tubes.

A still further object is to provide a self contained boiler unit that is held in the proper shape by these tubes and in this way save the expense of any steel superstructure to support the boiler. By doing this I secure a more uniform expansion throughout the boiler and setting for it is obvious t if all parts have the same temperature or the va ion is general, the boiler and setting will expand with a breathing action as the temperature rises or fails and therefore the strains will net be excessive and the lining will last much longer or for the life of the boiler.

A still further object is to provide a boiler and setting that is supported at ythe central portion only by meansy of retained rollers that allow the necessary expansion in every way: instead of hanging the heavy boilers from steel superstructures near the roof of the boiler room. The drum 5 itself when considered as a beam is well able to support the boiler so that in my invention I use the drum` asv a beam and by adding additional rows of boiler tubes at the sides, ends, top or bottom whereY needed I provide an excellent sup- 101 port for the fire brick walls, and by so doing provide a reinforced furnace wall which is watercooled whereby the strength of steel reinforcing tubes is insured.

In the accompanying drawings- 151 Fig. l is a half longitudinal section and elevation of a powdered fuel red boiler constructed in accordance with my invention.

Fig. 2y is half longitudinal section and elevation of the end view of a powdered fuel fired boiler.

Fig. 3 is a plan view of. a powdered fuel fired boiler shown in Figs. 1 and 2.

Fig. 4 is a partial end elevation of the middle drumsv of apowdered fuelfired boiler enlarged to show the roller construction that allows expansion of thel above boilers.

Fig. 5 is a partial sectional View taken on line 5 5V of Fig'. 4.

Fig. 6 is a partial' section of the lower part of the re brick lining showing the bricks reversed every other row so that one tube is exposed to the direct action of the flames and the next insulated from the flames by fire brick so that the boilerI circulation is positive one tube hot or the riser and the next cooler allowing circulation, as shown on 6 6 of Fig. 1.

Fig. '7 is a longitudinal sectional elevation showing another type of powdered fuel fired boiler.

Fig. 8 isa half section and elevation of. the end 40 of a powdered fuel i'lred fire box, the section is taken on line 8--8 of Fig. 7.

Fig. 9 is a sectional plan view broken away to show the detailed construction of the walls and corner headers as shown on line 9,-9 of Fig. 7. 45

Fig. 10 is a longitudinal sectional elevation showing my invention as applied to the i'lre box of a Stoker fired boiler water cooled.

Fig. 11 is a half elevation and half sectional elevation as shown on line II-II of Fig. 10.

Fig. 12 is a partial section of a nat arch over the nre of a boiler having the arch brick supported by a steam superheater.

Fig. 13 is a partial end elevation of a boiler equipped with a flat arch.

Fig. 14 is a detailed view of a block used on my invention shown in Figs. 2 and 12.

Fig. 15 is a front elevation of my retained U shaped brick.

Fig. 16 is an end view of my U shaped brick.

Fig. 1'7 is a sectional plan view of my U shaped brick taken on line I1-I1 of Fig. 15.

Fig. 18 is a front elevation of my retained U shape brick showing a hanger attached to the tube for supporting the tube and brick Work on long walls.

Fig. 19 is an end elevation of the hanger only. Referring, by numerals, Vto the drawings I0 designates the top original boiler drums as used on boilers of this type, and I I designates the lower original drums shown in the central part of Figs. 1 and 2. The mud drum I2 and the drums I0 and II are connected by tubes I3 which support brick I4 and circulate the water between drums I and I I thereby cooling brick I4, and. provide the two end walls I5 between drums IIJ and II, thus retaining the heat within the boiler setting. Extending downwardly from drums II are tubes IB that connect into mud drums I2. Loosely secured by clips I1 to tubes I6 are brick I4 forming the lower end walls between drum I I and mud drum I2. Under drum II a space I8 is provided for expansion of end walls I5. Tubes IS are bent to provide an arch 33 under drums II for the admission of the powdered fuel that is blown through pipes I9 that guides the fuel through the apertures 20 in arch 33. The fuel is ignited after coming into the re box, the ilames sweeping downwardly so that the Water in tubes I6, 2l, mud drum I2, and vertical header 35 is subjected to the heat of the flames which water in turn keeps the brick I4 below their dangerous temperature. The flames then sweep upwardly through boiler tubes 22 common to boilers of this type.

Connecting lower drums II above end walls 34 are large tubes 24 having ends 25 closed. Connected to tubes 24 are small tubes 2I terminating in Verticle drums or headers 35 which are connected into the ends of mud drums I2 so that the complete lower portion of the boiler setting is connected into the boiler circulatory system. All tubes are covered with iire brick or other suitable refractory material. Brick I4 are laid with one course having slot 21 turned inwardly exposing the tube to the direct action of the flames and the adjoining rows have slot toward the outside thus interpcsing a thin wall to the ames as shown clearly in Fig. 6. This is done to insure proper boiler circulation for the tubev exposed to the iiames will be the hot or risers and the tubes protected by the re brick will be the cooler or down comers thus the contained water will cirf culate. y

Laid on the upper side of large tubes 24 are common re brick forming wall 3| through which are openings 3! for cleaning or inspecting the boiler apparatus. Above walls 3I are walls 32 laid up with bricks as shown in Fig. 14 having each a hole 35 therethrough and the tubes 31 being extended through walls 32 and into headers on each side, said tubes 31 being extended from steam header 38 into superheated steam header 39 as shown in Fig. 3. The steam header is connected'by large radius bend 40 to boiler outlet 4I so that the steam collected in the upper boiler drums is led through the upper side walls 32 which are hot from the hot gases'from the powdered fuel and in this way the walls are cooled by the steam and the steam is superheated. The

superheater tubes are insulated by the brick so that their life is greatly prolonged. The superheated steam is then led to the power units through pipes 42.

Upper walls I5 where they enter drums I0 have 5 openings 43 formed by omitting brick I4 at this point so as to allow the smoke to escape to the smoke stack 44 through breeching 45 built in the form of a hollow wall of metal resting on bend 46 of tubes I3 and also supported by braces 41 10 attached to the upper part of drums I0. The upper part of breeching 45 has a pipe connection 48 connected to spiral tubes 49 located in the brick work of the stack. Only a portion of the spiral tube 49 is shown in the drawings, but this 15 tube will preferably extend to the top portion of the stack and thence to the water main or pump which forces the cold water up to the top of the stack and down through the stack into the hot breeching and'from the lower part of the breech- 20 ing to the mud drum I2. The water passing through the spiral tube 49 is the feed water for the boiler and said feed water would be forced into the coldest part and then down through the hotter part of the stack thereby saving a part 25 of the heat that has been heretofore lost through the stack.

Stack is laid with brick similar to I 4 having the tube 49 exposed to the hot gases, these tubes will become covered with soot and to keep these tubes 30 free from soot I provide an air pipe 50 extending upwardly in the center lof the stack 44 having small pipes or nozzles 5I extending radially from air pipe 50.

Heretofore the boilers have usually been sup- 35 ported by structural steel superstructures on the outside of the settings and are hung from up near the roof of the boiler house thereby making it necessary to use vast quantities of steel in the construction of the boiler house so as to safely 40 carry this heavy load, and often conining the Walls of the boiler setting between steel channels so that as the re brick become hot and expand enormous loads are thrown onto these steel members or else the re brick walls fail from crushing. 45 My invention overcomes these serious objections by allowing free expansion of the steel and iire brick, allowing the boiler to have a breathing action.

On the ends 52 of drums I I are welded brackets 50 53 having grooves 54 formed thereon. The brackets 53 rest on rollers 55 that in turn rest in cradle 55, said cradle being provided with limiting grooves 51 formed on the underside thereof that coincide with rollers 58 resting on plate' 59 55 which plate is attached to beam G. The beam 6!) is secured to columns 6I that are anchored into piers 62 below the boiler setting. The rollers as shown allow a free restricted movement as the boilers and setting expand in any way. This con- 60 struction allows the lower part below the rollers to expand downwardly and the upper part to expand upwardly for at the top of breeching 45 a circular groove 25 is provided to hold sand 63. Extending downwardly from the base of stack 44 is a circular 65 metal casting that fits into the sand 63 thereby forming a simple sand seal to keep the smoke from escaping before going through the stack and also allows the upper part of boiler setting to expand upwardly. The stack is supported independently 70 from the building structure that supports casting 64, this building steel not shown.

Figures '1, 8, and 9 show my invention as applied to an inclined tube cross drum boiler having the front water leg 65 and rear water leg 6E made 75 Wider so as to allow room for a row of tubes on each side of the bo-iler -to support brick `61 that form the two upper side wallsopposite the inclined tubes commonly used boilers of this type. Water leg 65 connects into the drum .68 having the bottom part resting on and connected into small drum 69.' Connected into the bottom of drum 69 are small tubes 19, bent so as to form a dat arch 1i for the .admission of the powdered fuel through -pipe 12. Tubes 1|] terminate in small mud drum 13 and act as supports for front wall 14 which has the brick I4 secured loosely thereto aspreviously described. vBrick I4 are reversed in this Wall having vthe tubes exposed to the -ames at the top, and near the bottom where the ashes are likely to form the tubes are covered by reversing bricks I4 so as to be kept free from the ashes.

Mud drum 13 is connected to small rear drum 15 by bottom tubes 16 which are on the same angle as the boiler tubes 11 so as to provide for an angled bottom of the fire box .so that the ashes will slide down the bottom and thence out of the fire "box through ash door 18 which is formed by omitting several of the bottom brick 19 when the bare tubes are exposed forming a grate. Ends of walls 8B are large tubes 8| connected into ends 82 of drums 69, 15 and 13, having sidewall tubes 83 expandedinto same at the front and terminating in large tubes 84 forming the rear corners. Large tubes 84 connect into the water leg 6B and the bottom end into rear drum 15 at the ends B5, as shown in Fig. 9.

Feed water passes through spiral tube 49 that is covered by brick 19 so as to keep the tubes clean and free from soot so that the heat will penetrate the water in the tubes at auniform temperature, thence through feed water pipe 86 and into mud drum 13.

In a boiler as shown on Figs. '1 and 8 every brick in the boiler setting is cooled by the boiler water, all brick are conned in a pipe rack that supports the complete boiler setting thereby eliminating the necessity of using any structural steel, thus saving vast sums of money in the installation of the boiler. As the complete setting has about the same temperature or a uniform temperature the expansion will be equal, and as this temperature never gets above the dangerous temperature of the re brick, the expansion will be the minimum.

A further object of my invention is to provide an air cooled space l i3 around the bottom part ofthe fire box so that should any of the furnace heat penetrate the brick walls above drums 13 and '15 the preheated air will be drawn into the furnace through openings H4 and H5.

Wall EHS shown as a heavy line does not touch the brick work at any place and is preferably made of sheet steel so that should any expansion take place as the temperature of this wall increases the wall will bulge slightly thus compensating for the expansion. Further this wall will keep any of the powdered fuel from rescaping lto the boiler room thereby causing an explosion for the finely ground coal is very explosiveY and Acare should be taken in handling this dangerous.

material.

Figures and ll show my invention as applied to a stoker fired boiler and Where it is desired to only cool and protect the brick work of the re box over and around the stoker, indicated in outline in dotted line 86 in Fig. 10. The stokeris fed by coal through hopper 81 from spout 83. Over stoker 35 near hopper 81 are brick y89 supported and cooled by tubes Si] which are connected into large U shaped headers 9| shaped to conform to the front end of re box. Tubes 92 also terminate Vin .these headers `9| :and form a pipe rack for supporting the front wall fire brick having the tubes 92 exposed to the action of the ames.

The .arch over the fire is also supported by tubes .5

93 that support brick 94 thus providing a fiat arch which spreads the fiames and thereby heats the boiler tubes, no-t shown, more uniformly. The tubes 93 termina-te in a U shaped header 95 at the rear .end of the re box. The boiler feed 10 water is admitted through flanged pipe opening :shown in Fig. l1 and as this part of the boiler system is the lowest, the fire box pipe rack will always be full of water and as this water becomes yhot the circulation will force it upward through `pipe B1 that lis connected into the boiler proper.

Another important feature of my invention is that the complete fire box can be removed from under the boiler as a whole by simply disconnecting the feed `water pipe connection and the discharge pipe connection that connects to the boiler, the complete fire box is then pulled from under the boiler .and a .new re box similar to the old can then be put in place and the pipe connections made, when the boiler is again ready for operation. This is important for it is more economical to provide a spare fire box than it is .to provide a spare boiler as is now the common practice in boiler room operation.

A lrire box as above described will last the life .of the boiler for it is impossible to heat the brick .above their dangerous temperature. Instead of burning .out the expensive fire brick and causing a serious loss due to the fact that the boiler is shut Ydovvn duri-ng repairs that are so often needed now I use the wall surfaces for additional heating surfaces toward the boilers final product; steam.

Another important feature of my invention is the simple shaped re bricks used, for in the manufacturing-of fire brick it is necessary to carry .a number of brick in stock and thereby avoid the Vdelay of having to manufacture special shaped nre brick, when the customers need the fire brick for repairs.

In ,operating the present stoker red boilers the arch over 'the names .burns out very quickly, and the complete combustion of the fuel cannot be obtained for the usual fire brick arch fails when the boiler is forced to any great degree. My invention also permits forcing .the boiler to the utmost due to the cooling action of the feed water, without in any way interfering with the production of steam. Furthermore the strength of the steel :tubes is in no way impaired by the heat due to the cooling action of the feed water for it vis impossible to get these tubes red hot.

Figs. 12 .and 13 show my invention as applied to a fiat -arch over a fire box or furnace that requires a steam superheater and has no room for the-usual type of steam superheater or the boiler Yowner may desire to resuperheat the steam after it has performed a part of its function.

Boiler outlet pipe -98 broken away leads the boiler steam to steam header v99 which has smaller tubes I D0 through arch brick 1.9 forming the arch 65 IUl. Thus the invention provides an insulated superheater .over the hottest part of the furnace. The tubes |00 are connected into header 99 and superheated steam header |02 so that all steam from the boiler is .circulated through the hot brick work composing arch l D I .thereby cooling the :hot brick and steel tubes .to below their dangerous temperature and in doing this the boiler steam temperature is greatly raised or superheated. The super-heated steam header has a flanged connection to which the necessary p-ipe is connected that leads the superheated steam to the power unit.

The most commonly used arches of the present day are built of wedge brick in the form of an arch and frequently fail by burning out or by crushing due to expansion strains set up when the confined arch gets hot so that it is imperative to allow for free expansion to obtain the best results. Fire brick will expand up to the temperature at which they are burned in the brick kilns and after this temperature has been exceeded they begin to shrink so that at so-me time after the fire is put under the arch the action of the arch changes from expansion to shrinkage. The tests performed by the Department of the Interior, Bureau of Mines las shown in their bulletin 223 clearly show that the temperature of the furnace changes inside of the furnace.

4That is along the walls the temperature is lower than it is in the central part of the furnace re.

Undoubtedly the same conditions prevail inside of the brick kilns sol that the temperatures at which these brick are burnt are in question, so that the boiler operator whose duty it is to ease upon the buck stays While the expansion is taking place must use judgment only when he has to begin tightening up the buck stays. This condition my invention overcomes, for set on the top of the furnace side walls |03 are T rails |04 that support the tubes |00. T rails |04 keep the arch brick forming arch IOI above the brick work forming the side walls so that the brick arch does not touch the side walls leaving an open space |05 which is lled with loose sand around the joints of the three sides so as to provide a tight furnace so that the heat cannot escape before performing its function.

A flat arch as above described pro-vides for contraction or expansion, for the tubes are free to slide on the T rails with the minimum friction.

and should the brick expand more than the tubes they not being securely fastened to the tubes, slide on the tubes with the least friction. Should the complete arch expand in any way the loose sand will yield and still maintain a tight furnace. This provides a oating arch that is free to expand regardless of the brick or tube temperatures.

A further object of my invention is to provide a flat arch that can be assembled completely before being put in place in the furnace for, if the arch fails in any way the defective arch can be readily removed by disconnecting the two pipe fittings and lifting the complete arch from the T rails. A new arch may be then set in place, the two pipe connections made, loose sand put in place and the boiler is again ready for operation.

A further object of my invention is to provide a superheated steam cooled flat arch which will allow a higher temperature in the furnace due to the furnace being cooled below the dangerous temperature of fire brick and tubes, by using steam. It is of course understood that my invention can be used for either water, steam or vapor that is used to develop power for the power house.

It is further understood that my invention abovedescribed in the several different types of boilers can also be cooled by steam if desired.

Tubes |00 are equipped with standard pipe Ts IIB on each end having plugs |08 screwed in place so as to provide a way to clean and inspect arch tubes |00. Ts I0 have vertical pipes ||2 connected thereto and extending upwardly and into steam headers 98 and |02 so as to allow for any expansion of tubes |00 for these vertical tubes ||2 will spring slightly without injury.

A further object of my invention is to provide 5 blocks made of nre clay or other suitable refractory material that can be removed without disturbing the rest of the furnace wall. Figures 15, 16, and 17 show a block or re brick I4 that is U shaped having slot 21 formed to allow the 10 brick to be put in place on the tube. Formed in each brick at the opposite ends thereof are pairs of curved indentations |01. I1 designates pipe clips which fit closely within the indentations |01 and retain the brick on to the tubes 15 in any position. Brick I4 are put in place on the tubes, clips I1 are then put in place on the tubes as indicated in dotted lines on Fig. 15 so that the circular indentations |01 register in a direction circumferentially of the tubes with clips 20 I1 and then the clips are rotated into the circular indentations and because the distance between the upper portions of a pair of oppositely disposed clips I1 is less than the diameter of the tube the brick may not move downwardly with 25 respect to said tube while the clips are in place.

U shaped brick I4 also permits me to either expose the tubes to the directV action of the ames or else interpose a thin fire brick wall to provide an insulator or else keep one tube cooler 30 than the other. A very important point when it is desired to insure boiler circulation. The clips |01 are arranged in position one at a time, the rst clip being located in the dotted line position shown in Fig. 15 and being rotated into one of 35 the indentations before the second clip is a1'- ranged in position in a like manner.

Figs. 18 and 19 show pipe hangers |09 shaped to t the tube at one end and the other forming a jaw I I 0 for any suitable support. Pipe hangers 0 are clamped together securely on the tubes by bolts III. The pipe clamps also act as clips to retain the brick to the tubes so that by substituting the pipe clamps for a pair of clips I maintain a tight wall at this point.

I claim- 1. A furnace comprising an intermediate support, wall portions suspended from said intermediate support, wall portions supported by said intermediate support above same, and fluid con- 50 ductors arranged in said walls to prevent overheating thereof, said uid conductors constituting the sole connection between said walls and vsaid intermediate support.

2. A furnace comprising a drum forming a part 55 of the circulatory system of the furnace, tubes arranged in communication with the interior of said drum and extended upwardly therefrom, tubes arranged in communication with the interior of said drum and suspended therefrom, the 60 first-mentioned tubes and the second-mentioned tubes being parts of the circulatory system of the furnace, and refractory members arranged to produce the walls of the furnace, said refractory members being provided with openings formed 05 therethrough through which said tubes extend, and said tubes constituting the sole connection between said walls and said drum.

v3. A furnace comprising a wall composed of tubes and refractory members supported by said 70 tubes, each of said refractory members being in.- tegrally formed and of approximately U-shaped construction to permit same to be moved onto and oif of the associated tube by being moved laterally with respect thereto, and arcuate clips for 75 retaining said refractory members in place on said tubes, said refractory members being provided with arcuate depressions in which said clips are located in a manner to contact firmly with the faces of said tubes and the walls of said arcuate depressions. Y

4. A boiler furnace having a combustion chamber, a row of spaced metallic tubes arranged along a Wall of the chamber so that a fluid flowing through them absorbs heat transmitted through the tube walls from burning fuel in the furnace, a row of preformed refractory blocks carried wholly by each tube along its furnace side and separate clips holding each of said blocks tied to the tubes so that each of the blocks can be separately released and replaced.

5. A boiler furnace having a combustion chamber, a row of spaced metallic tubes arranged along a wall of the chamber so that a fluid flowing through them absorbs heat transmittedl through the tube walls from burning fuel in the furnace, a row of preformed refractory blocks carried wholly by each tube along its furnace side, said blocks having recesses and separate clips entering said recesses and holding each of said blocks tied to the tubes so that each of the blocks can be separately released and replaced.

6. A boiler furnace comprising a wall composed of elongated upright tubes forming part of the circulatory system and refractory members supported by the tubes at the lower ends of the latter and free to expand upward with respect to said tubes, said refractory members-being approximately U-shaped with the open side inward on some of said tubes and the closed side inward on others, to provide an upward flow in the exposed tubes and a downward iiow in those covered by the refractory.

CHARLES B. YODER. 20

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