US2042643A - Furnace - Google Patents

Description

June 2, 1936 R. voN MATTEKovll-l 2,042,643

FURNACE Filed May 25, 1934 Q Y im,

Patented June 2, 1936 UNiTED STATES PATENT OFFICE FURNACE Rudolf von Mattelmvich',v Rosalie, near Brisbane, Queensland, Australia 20 Claims.

1n a broad sense, this invention relates to furnaces in which a fuel supply chute or shaft is isposed between a main and a subsidiary regrate for the purpose of enecting dehydration or carbonization of the fuel, and particularly refers to improvements in the construction of said grate shaft.

The present application is a continuation in part of my copending application, Serial No.

f' 516,772, filed February 18, 1931.

One of the Objects of this invention is to provide a fuel chute or shaft for supplying fuel to the fire of a boiler heating furnace and in circulating water from one boiler drum to another through tubes forming the walls of the fuel chute.

Another object of this invention is toprovide a fuel chute or shaft for supplying fuel to the fire of a boiler heating furnace, the walls of the chute being formed of water tubes through which water is circulated from one boiler drum to another and in which the tubes of one of the walls are connected at both ends to other tubes subjected to heat from a fire-grate to provide for an independent circulation of water to absorb a portion of the heat from said nre-grate.

Still another object of this invention is to provide a water cooled fuel chute for supplying fuel to the nre-grates of a furnace, in which chute the fuel is heat treated to obtain the maximum amount of heat energy therefrom.

With these and other important objects in View, which may be incident to my improvements, the invention resides in the parts and combinations to be hereinafter set forth vand claimed, with the understanding that the several necessary elements comprising my invention may be varied in construction, proportions and arrangement, without departing from the spirit and scope of the appended claims.

ccording to the present invention, the fuel supply chute or shaft is formed by or between parallel legs of two separate tubular units of tubular structure, each unit being a complete water circulating system in itself and in parallel with the boiler which the furnace is intended to heat. Each unit comprises suitable headers connected with one another byV rows of tubes across the width of the furnace. The parallel portions of these two tubular structures are spaced apart to constitute between them the grate supply chute which is preferably perpendicular.

In order to make the character and import of my invention clear, reference will be made to the accompanying drawing in which:

Figure 1 shows a longitudinal sectional eleva.- tion of one form of the apparatus in its relation to a boiler. Y

Figs. 2 and 3 are diagrammatic views of two modifications.

The grate shaft is formed by the combination of two entirely separate units of tubular structures, each unit being a complete circulating system in itself and being connected in parallel with the boiler. The grate supply shaft is bounded by the perpendicular tube walls BA and B1 which extend across the full width of the furnace.

Unit B is shown in Fig. 1 as made up by means of three headers G, F, and Fl which are connected with one another by rows of tubes B, 32 and D. G is the receiving header, which is fitted with blow down connections (not shownl. F is the returning header from which risers H take the steam to the top boiler drum J.

The inclined tubes B2 are exposedV to direct o radiation from grate A. Only one row of tubes is shown in the drawing, but two or more rows of tubes may be used in accordance with Vthe purpose of lowering the temperature of Vthe fire-gases to a degree in agreement with requirements and 25 prior to their passing through the fuel column. Circulation in this unit B, B2, andV D, as a system in itself is established by the horizontal tubes D which also support the roofing. tiles D1.

Unit B1 is shown as comprising twoheaders, 30

the upr header G1 being the receiving header. The lower header G2 functions also as a mud drum and is therefore provided with blow-down connections (not shown) The tube wall B1 bounding the grate shaft forms the cold leg in this circulating system and the hot leg. is represented by the tube wall l-I2 which connects the headers directly with the steam drum J of the boiler.

The tube wall H1 may be fully or only partly exposed to radiation from grate E by arranging the placing of tiles H30 forming the partition between the subsidiary and main combustion chamber Vbehind or between the tubes I-I.

Alternatively, as shown in Fig. 2 ofthe drawing, the lower header G20 may be in communication withy the water drum J1 of the` boiler, and then the upper ends of tubes Hl'are expanded into header G10, from which risers H20V take the" steam to the top drum J of the boiler similarly as shown for unit B.

Unit B may also be constructed with two headers only by using tubes suitably bent' as in Fig'. 3. Drum G is, of course, connected as in Fig. 1 to drum J1.

Passing through the spaces provided by the lower staggered portion of the tube wall B1 the flue gases Vfrom the subsidiary chamber, the expelled vapor and volatiles from the fuel and the incoming top `air travel over and above the hotter gases arising from grate E. The large difference in density between the cooler mixture containing excess air and the hotter gases from the fire on the main grate induces ready mingling and subsequently efficient combustion.

' The movable floor O controlsthe flow of fuel in both directions and in required proportions to the two furnace grates, respectively. This floor serves as a fuel shed for the main grate, whereas the refractory blocks S serve as a fuel shed for the subsidiary grate.

Top air enters the furnace through the opening P1 provided in the upper wall to the right of header G1 and directly above header G2.

The improvements herein described afford notable advantages shared by none of the known combinations. The most salient advantages are:

Vl. The substantial addition of highly efficient heating surface to that of the boiler;

2. Considerable gain of heat transfer, due to the front of the tube bundles in both furnaces being exposed to the radiant heat of the fuel bed; and Y 3. Highest possible combustion efficiency owing to:

' (a) The combustible gases emerging from the fuel chute or shaft together with the vapor from the expelled moisture in the fuel, the flue gases from the subsidiary chamber and the incoming top air readily mingling with the gases arising from the main re by being made to travel over and above the hotter gases within the furnace, as this leads to an eddying action due to the greater density of the much cooler mixture.

(b) The largely reduced amount of excess air, due to the excess air admitted into the subsidiary furnace becoming again available as top air in the main furnace. For instance, if onethird of the fuel is burnt in the subsidiary furnace and two-thirds in the main furnace, and.

each furnace operated with 33% of excess air, then, yowing to the gases entering into the main combustion chamber from the subsidiary chamber already containing excess airrcorresponding with the requirements of one-third of, the fuel, the weight of excess air to be added for combustion in the main furnace is equivalent to that supplied into the subsidiary furnace; thus, all of the fuel is burned with only 22% of excess air, although each furnace is operated individually with 33% of excess air.

While I have shown and described the preferred embodiment of my invention, I wish it to be understood that I do not conne myself to the precise details herein set forth by way of illustration as it is apparent that many changes and variations may be made therein by those skilled in the art, without departing from the spirit .of the invention or exceeding the scope of the appended claims.

I claim as my invention:-

l. In a boiler heating furnace having a main and a subsidiary lire-grate, a fuel delivery chute above and between said main and subsidiary re-grates for the pre-treatment of fuel prior to its delivery on to the flre-grates, means for providingthe ready mingling of the combustible gases with top air in a separateY space and the enforced travel of the gaseous mixture over and above the main nre, said separate space being bounded by water tube walls, the tube wall facing the main fire being partly exposed to radiant heat from the main grate, and partitioning refractory tiles mounted on said tube wall facing the main nre-grate.

2. In a furnace of the class described for heating a boiler having upper and lower drums connected by tubes, a main fire-grate and a subsidiary fire grate, a vertically arranged fuel delivery chute positioned to deliver fuel in determined proportions to both of said re-grates, said delivery chute comprising a pair of spaced walls extending across said furnace, said walls being formed of tubes, the tubes in one wall having their ends connected to tubes positioned above one .of the fire-grates to provide for an independent circulation of water to absorb a portion of the heat radiated from said fire-grate, and means for separately connecting the tubes of each wall to the upper and lower drums of the boiler for the circulation of water from one drum to the other through the wall tubes.

3. In a furnace of the class described for heating a boiler having upper and lower drums connected by tubes, a main fire-grate and a subsidiary lire-grate, a vertically arranged fuel delivery chute positioned to deliver fuel in determined proportions to both of said fire-grates, said delivery chute comprising a pair of spaced walls extending across said furnace, said walls being formed of tubes substantially vertically `arranged and horizontally spaced, upper and lower headers connecting the upper and lower ends of said tubes, respectively, conduits connecting the lower drum rof the boiler with the lower header of one set of wall tubes, conduits connecting the upper header of this set of tubes with the upper boiler drum, other conduits connecting the upper and lower headers of the other set of wall tubes with the lower and upper boiler drums, respectively, and still rother conduits ccnnecting the upper header of said last-named set of wall tubes with the upper boiler drum.

4. In a furnace of the class described for heating a boiler having upper and lower drums connected by tubes, a main fire-grate and a subsidiary fire-grate, a vertically arranged fuel delivery chute positioned to deliver fuel in determined proportions to both of said re-grates, said delivery chute comprising a pair of spaced walls extending across said furnace, said walls being formed of tubes substantially vertically arranged and horizontally spaced, upper and lower headers connecting the upper and lower ends of said tubes, respectively, conduits connecting the lower drum with one header of each set of wall tubes, and conduits connecting the upper rdrum with other headers of the sets of wall tubes, the tubes in one wall having their ends connected to tubes positioned above one of the re-grates to provide for an independent circulation of water to absorb a portion of the heat radiated from said fire-grate.

5. In a furnace of the class described for heating a boiler having upper and lower drums connected by tubes, a main fire-grate and a subsidiary lire-grate, a vertically arranged fuel delivery chute positioned to deliver fuel in determined proportions to both of said fire-grates, said delivery chute comprising a pair of spaced walls extending across said furnace, said walls being formed of tubes substantially vertically arranged and horizontally spaced, upper and lower headers connecting the upper and lower ends of said tubes, respectively, conduits connecting the lower drum of the boiler with the lower header of one set of wall tubes, conduits connecting the upper header of. this set of tubes with the upper boiler drum, and other conduits connecting the upper and lower headers of the other set of wall tubes with the lower and upper boiler drums, respectively, the tubes vin one wall having their ends connected to tubes positioned above one of the fire-grates to provide for an independent circulation of water to absorb a portion of the heat radiated from said fire-grate.

6. In a furnace of the class described for heating a boiler having upper and lower drums connected by tubes, a main fire-grate and a subsidiary fire-grate, a vertically arranged fuel delivery chute positioned to deliver fuel in determined proportions to both of said re-grates, said delivery chute comprising a pair of spaced walls extending across said furnace, said walls being formed of tubes substantially vertically arranged and horizontally spaced, upper and lower headers connecting the upper and lower ends of said tubes, respectively, conduits connecting the lower drum of the boiler with the lower header of. one set of wall tubes, conduits connecting the upper header of this set of tubes with the upper boilei` drum, other conduits connecting the upper and lower headers of the other set of wall tubes with the lower and Lipper boiler drums, respentively, and still other conduits connecting the upper header of said last-named set of wall tubes with the upper boiler drum, the tubes in one wall having their ends connected to tubes positioned above one of the re-grates to p-rovide for an independent circulation of water to absorb a portion of the heat radiated from said fire-grate.

'7. In a furnace of the class described for heating a boiler having upper and lower drums connected by tubes, a main fire-grate and a subsidiary nre-grate, a vertically arranged fuel delivery chute positioned to deliver fuel in determined proportions to both of said re-grates, said delivery chute comprising a pair of spaced walls extending across said furnace, said walls. being formed of tubes substantially vertically arranged and horizontally spaced, upper and lower headers connecting the upper and lower ends of said tubes, respectively, conduits connecting the lower drum of the boiler with the lower header of. one set of wall tubes, conduits connecting the upper header of this set of tubes with the upper boiler drum, other conduits connecting the upper and lower headers of the other set of wall tubes with the lower and upper boiler drums, respectively, and heat resisting tile covering the portions of the conduits extending from the lower header of, one wall tube set to the upper drum of the boiler to reduce the heating effect on said conduits, the tubes in one wall having their ends connected to tubes positioned above one of the iire-grates to provide for an independent circulation of water to absorb a portion of the heat radiated from said fire-grate.

8. In a furnace of the class described for heating a boiler having upper 'and lower drums connected by tubes, a main fire-grate and a subsidiary fire-grate, a vertically arranged fuel delivery chute positioned to deliver fuel in determined proportions to both of said re-grates, said delivery chute comprising a pair of spaced walls extending across said furnace, said walls being formed of tubes substantially vertically4 arranged and horizontally spaced, upper and lower headers connecting the upper and lower ends of said tubes, respectively, conduits connecting the lower drum with one header of each set of wall tubes, and conduits connecting the upper drum with other headers of the setsof Wall tubes, the tubes in each wall having their ends connected to tubes positioned above the respective re-grates to provide for an independent circulation of water to absorb aportion of the heat radiated from the nre-grates.

9. In a furnace of the class described for heating a boiler having' upper and lower drums connected by tubes, a main fire-grate and a subsidiary iire-grate,-a vertically arranged fuel delivery chute positioned to deliver fuel in determined proportions to both of said fire-grates, said delivery chute comprising a pair of spaced Walls extending across said furnace, said walls being formed of tubes substantially vertically arranged and horizontally spaced, upper and lower headers connecting the upper and lower ends of said tubes, respectively, conduits connecting the lower boiler drum with the lower headers of-both sets of wall tubes, and' conduits connecting the upper boiler drum with the upper headers of both sets of wall tubes, the tubes in one wall having their ends connected to tubes positioned above one of the nre-grates to provide for an independent circulation of water to absorb a portion of the heat radiated from said nre-grate.

l0. In a furnace of the class described for heating a boiler having upper and lower drums connected by tubes, a main fire-grate and a subsidiary fire-grate, a vertically arranged fuel delivery chute positioned to deliver fuel in determined proportions to both of said fire-grates, said delivery chute comprising a pair of spaced walls extending across said furnace, said walls being formed of tubes substantially vertically arranged and horizontally spaced, upper and lower headers connecting the upper and lower ends of said tubes, respectively, conduits connecting the lower boiler drum with the lower headers vof both of wall tubes, and conduits connecting the upper boiler drum with the upper headers of both sets of wall tubes, the tubes in each Wall having their ends connected to tubes positioned above ti e respective fire-grates to provide for an independent circulation of water to absorb a portion of the heat radiated from the re-grates.

1l. In a furnace of the class described for heating a` boiler having upper and lower drums connected by tubes, a main fire-grate and a subsidiary fire-grate, a vertically arranged fuel delivery chute positioned to deliver fuel in determined proportions to both of said re-grates, said delivery chute comprising a pair of spaced walls extending across said furnace, said walls being formed of tubes substantially vertically arranged and horizontally spaced, upper and lower headers connecting the upper and lower ends of said tubes, respectively, conduits connecting the lower druniof the boiler with the lower header of one set of wall tubes, conduits connecting the upper Y header of this set of tubes with the upper boiler drum, other conduits connecting the upper and lower headers of the other set of wall tubes with the lower and upper boiler drums, respectively, and heat resisting tile covering the portions of the conduits extending from the lower header of one wall tube set to the upper drum of the boiler to reduce the heating effect on said conduits.

l2. In a furnace of the class described for heating a boiler having upper and lower drums connectedV by tubes, a main fire-grate and a subsidiary nre-grate, a vertically arranged fuel delivery chute positioned to deliver fuel in determined proportions to both' of said fire-gratas, said delivery chute comprising a pair of spaced walls extending across said furnace, said walls being formed of tubes substantially vertically arranged and horizontally spaced, upper and lower headers connecting the upper and lower ends of said tubes, respectively, tubes extending'horizontally over the subsidiary fire-grate from the upper header of one set of wall tubes, a header connecting the free ends of the horizontal tubes, `tubes connecting the last-mentioned header with the lower header of the wall tubes and positioned to receive heat from the subsidiary fire-grate, and conduits connecting the upper andlower boiler drums with the headers of the Wall tubes t provide for circulation of water from one drum to the other.

y 13. In a furnace of the class described for heating a boiler having upper and lower drums connected by tubes, a main fire-grate and a subsidiary fire-grate, a vertically arranged fuel delivery ehute positioned to deliver fuel in determined proportions to both of said re-grates, said delivery chute comprising a pair of spaced walls extending across said furnace, said walls being formed of tubes substantially vertically arranged and horizontally spaced, upper and lower headers connecting the upper and lower ends of said tubes, respectively, tubes extending horizontally over the subsidiary fire-grate from the upper header of one set of wall tubes, a header connecting the free ends of the horizontal tubes, tubes connecting the last-mentioned header`with the lower header of the wall tubes and positioned to receive heat from the subsidiary nre-grate, conduits connecting the said last-mentioned header with the upper boiler drum, conduits connecting the lower header of the tubes adjacent the subsidiary grate with the lower boiler drum, and conduits connecting the upper and lower headers of the other set of wall tubes with the lower and upper boiler drums, respectively.

le. In a furnace of the class described for heating a boiler having upper and lower drums connested by tubes, a main fire-grate and a subsidiary fire-grate, a vertically arranged fuel delivery chute positioned to deliver fuel in determined proportions to both of said iire-grates, said delivery chute comprising a pair of spaced Walls extending across said furnace, said walls being formed of tubes substantially vertically arranged and horizontally spaced, upper and lower headers connecting the upper and lower ends of said tubes, respectively, tubes extending horizontally over the subsidiary fire-grate from the upper header of one' set of wall tubes, a header connecting the free ends of the horizontal tubes, tubes connecting the last-mentioned header with the lower header of the wall tubes and positioned to receive heat from the subsidiary fire-grate, other tubes positioned over the main fire-grate and connecting the upper and lower headers of the chute wall tubes adjacent the main nre-grate, and conduits connecting the upper and lower boiler drums with the headers of the tubes to provide for circulation of Water through the tubesV from one drum to the other.

15. In a boiler heating furnace having a main and a subsidiary fire-grate, a vertical fuel delivery chute positioned above and between said fire-grates for the pretreatment of fuel prior to delivery to said grates, said chute being formed of a pair of spaced tube walls extending between ,walls of said furnace, an auxiliary tube Wall positioned between said subsidiary fire-grate and said fuel delivery chute, and means connecting all of said tube walls with the boiler for the circulation of boiler water through said tube walls.

16. In a furnace of the Vcharacter described, a subsidiary nre-grate, a main fire-grate, a boiler, means for conducting hot products of combustion from said main and subsidiary flre-grates to said boiler, a fuel delivery chute positioned above and between said fire-grates and in the path of travel of the products of combustion from said subsidiary fire-grate for the pretreatment and delivery of fuel to said flre-grates, said chute being formed of water tube walls extending between the side walls of the furnace, and an auxiliary water tube wall positioned between said subsidiary firegrate and the fuel chute for reducing the temperature of the combustion products from the subsidiary fire-grate before reaching the chute;

17. In a furnace of the character described, a subsidiary fire-grate, a main fire-grate, a boiler, means for conducting hot products of combustion from said main and subsidiary re-grates to said boiler, a. fuel delivery chute positioned above and between said fire-grates and in the path of travel of the products of combustion from said subsidiary nre-grate for the pretreatment and delivery of fuel to said re-grates, said chute being formed of water tube walls extending between the side walls of the furnace, an auxiliary water tube wall positioned between said subsidiary fire-grate and the fuel chute for reducing the temperature of the combustion products from the subsidiary fire-grate before reaching the chute, and means connecting all of the water tube walls with the boiler for the circulation of boiler water through said water tube walls.

18. In a furnace of the character described, a subsidiary fire-grate, a main fire-grate, a boiler, means for conducting hot products of combustion from said main and subsidiary re-grates to said boiler, a fuel delivery chute positioned above and between said re-grates and in the path of travel of the products of combustion from said subsidiary fire-grate for the pretreatment and delivery of fuel to said re-grates, said chute being formed 0f water tube walls extending between the side walls of the furnace, an auxiliary water tube wall positioned between said subsidiary fire-grate and the fuel chute for reducing the temperature of the combustion products from the subsidiary re- Y grate before reaching the chute, means connecting the upper and lower ends of said auxiliary tube wall with the upper and lower ends of the adjacent tube wall of the chute, and means connecting all of the water tube walls with the boiler for the circulation of boiler water through said water tube walls.

19. In a boiler heating furnace having a main and a subsidiary fire-grate, a vertical fuel delivery chute positioned above and between said fire-grates for the pretreatment of fuel prior to its delivery onto the fire-grates, said fuel delivery chute being formed between furnace walls by spaced tube walls, means connecting each tube Wall with the boiler for the circulation of boiler water through said tube walls, and a refractory baffle associated with said chute for deflecting gases from said subsidiary grate and from said chute over said main nre-grate to prevent their direct contact with heating surfaces of the boiler.

20. In a furnace of the character described, a subsidiary fire-grate, a main fire-grate, a boiler, means for conducting hot products of combustion from said main and subsidiary fire-mates to said boiler, a fuel delivery chute positioned above and between said re-grates and in the path of travel of the products of combustion from said subsidiary fire-grate for the pretreatment and delivery of fuel to said flre-grates, said chute comprising spaced Water tube walls, means connecting said Water tube Walls with the boiler for the circulation of boiler water through said Walls, and a baffle positioned between said fuel chute and said main fire-grate for deecting all gases down over said main re-grate.

RUDOLF voN MATTEKOVICH.

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