US2818048A - Boiler construction - Google Patents

Description

Dec. 31, 1957 Filed Oct. 22, 1954 J. F. Ross 2,818,048

BOILER CONSTRUCTION 3 SheetsSheet 1 EVE 27227? I Jose 011 F F055 Dec. 31, 1957 'J. F. Ross BOILER CONSTRUCTION 5 Sheets-Sheet 2 EDOOO 00000 08000 O OO OOOOQ LFEZZZLUT (Joseph F F055 Filed Oct. 22, 1954 Dec. 31, 1957 J. F. ROSS 2,8

BOILER CONSTRUCTION Filed Oct. 22, 1954 5 Sheets-Sheet 3 7 Joseph 11 R055 BOILER CONSTRUCTION Joseph F. Ross, Chicago, Ill.

Application October 22, 1954, Serial No. 464,010

3 Claims. (Cl. 122-42) This invention relates to improvements in the construction of boilers which provide steam for heating purposes, although the invention may have other uses and purposes.

More specifically, the invention relates to low pressure boilers of the combination water tube and fire tube type, wherein a water shell in which fire tubes are horizontally disposed overlies a conventional fire box and mud drums, side refractory walls enclose the fire box, and a vertically disposed series of water tubes lined along the refractory walls provide intercomrnunicating passages between the shell and mud drums.

Heretofore, low pressure heating boilers of the combination fire tube and water tube type have always disposed the water tubes horizontally over the fire box, and at the same time specifically provided individual access from the outside to each water tube for the purpose of inspection, and frequent cleaning thereof. The necessary cleanings were caused by the fact that the tubes were disposed in a horizontal position, and water passing therethrough tended to deposit its impurities on the inner surface of the water tubes causing decreased efiiciency of the boiler, and during the cleaning of the water tubes, the complete service of the boiler was lost.

Accordingly, it is an object of the invention to obviate the above difiiculties and provide a low pressure heating boiler which can be quite economically manufactured, is highly efiicient, requires less maintenance, and is safer in operation.

Another object of the invention is to provide a combination fire tube and water tube heating boiler, wherein the construction provides better water circulation, and diminishes the amount of water impurities deposited within the water tubes.

A further object of this invention resides in the provision of a combination fire tube and water tube boiler having vertical water tubes banked along the inner surface of the fire box refractory side walls.

Still another object of this invention is to provide a combination horizontal fire tube and vertical water tube boiler, wherein the vertical water tubes increase the water circulation and the boiler efiiciency, and decrease the scale forming tendencies within the water tubes thereby requiring less maintenance.

Another feature of this invention resides in the provision of a boiler having a water shell with two groups of horizontally positioned fire tubes therein, which directs the fire travel several times the length of the boiler permitting the water to absorb more of the useful heat units of the fire.

Still another feature of the invention is to provide a water boiler having horizontal fire tubes within the boiler shell, and horizontal and vertical water tubes presenting a large amount of heating surface to the high temperature gases.

Other objects, features and advantages of this invention will be apparent from the following detailed disclosures,

inited States Patent 2 taken in conjunction with the accompanying drawings, in which:

Figure l is a broken, side elevational view, partly in section, showing the relationship between the vertical water tubes and the horizontal fire tubes;

Figure 2 is a front elevational view of the embodiment of Figure 1, partly in section, illustrating the vertical disposition of the water tubes;

Figure 3 is a front elevational view, partly in section, of another embodiment of the invention wherein a single group of fire tubes are disposed within the boiler water shell and the vertical water tubes are disposed adjacent the back and the sides of the fire box;

Figure 4 is a plan cross sectional view of the second embodiment taken substantially along the lines I'V--IV of Figure 5; and

Figure 5 is a side elevational view of the second embodiment, partly in section, showing the relationship between the vertical water tubes and the horizontal fire tubes.

In Figures 1 and 2, the preferred embodiment of the invention illustrates a horizontal fire tube and vertical water tube low pressure heating boiler including a fire box 10 enclosed by a vertical front wall or boiler head 11, and a vertical rear wall or boiler head 12, side refractory walls 13 (only one of which is specifically shown in Figure 2), and an overlying water shell, generally designated at 14. The fire box 10 has the conventional'open bottom through which is received fire or heat from any suitable firing apparatus (not shown). A pair of fire doors 15 of the usual type are disposed in the front wall 11 providing access to the fire box 10. The fabrication of the boiler may be by welding, riveting, or some other equivalent means.

The water boiler shell 14 includes an outer elongated semi-cylindrical cover 16 with its open side facing downwardly and extending between the front wall 11 and the rear wall 12, a lower semi-cylindrical shell portion 17 of shorter length and smaller diameter than said upper cover 16 with its open side facing upwardly toward the open side of cover 16, and longitudinally disposed elongated flat plate portions 18 providing a ledge or shoulder of substantially the same length as the lower semi-cylindrical portion 17 extending between the downwardly projecting edges of cover 16 and the upwardly projecting edges of the semi-cylindrical portion 17, thereby defining the somewhat cylindrical boiler shell 14.

The forward end of the lower semi-cylindrical portion 17 terminates near the front wall 11, but is spaced therefrom, being connected to a front partitioning wall 19, as by welding or the like the latter lying in parallel spaced relationship with the front wall 11, and defining therebetween a fluid chamber or front water leg 20. Spaced from the rear wall 12 and in parallel relationship thereto is a vertical rear partitioning wall 21 of substantially rectangular shape, and it extends upwardly to the semicylindrical cover 16. Covering the rear end of the semicylindrical lower portion 17 of the boiler shell 14 is a properly sized semi-circular rear shell wall 22 which is substantially spaced in parallel relation from walls 12 and 21. Enclosing the rear open portion of the upper semi-cylindrical shell cover 16 is a horizontal shell wall 23 extending between the rear partitioning wall 21 and the semi-circular wall 22 of the lower shell portion 17. A rear water leg 24 defined by the spaced parallel walls 21 and 12 communicates at its upper end along the back of the boiler with the shell 14, and at its lower end on opposite sides of the boiler with the longitudinally extending side mud drums 25 (only one shown). The side mud drums 25 parallel the side refractory walls 13, and are disposed partially within a notched portion of said walls adjacent the lower'end of the refractory walls, as shown most clearly in Figure 2. The side mud drums 25 communicate 3 at their forward ends with the front water leg on opposite sides of the boiler.

Also intercommunicating the side mud drums and the boiler water shell are two banks of vertically positioned water tubes 26, one lying along or against each side refractory wall 13. Water tubes 26 parallel each other and are substantially equally spaced from the front of the boiler to the rear thereof along the refractory side walls 13, being secured in apertures of the side mud drums and apertures of the elongated connecting plate 18 of the boiler shell 14. Although the water tubes are described herein as lying along or positioned against the refractory walls, there may be small air gaps between the tubing and the adjacent wall such as those gaps caused by differential expansion between the walls and tubes, due to non-flatness of the wall, and the like. Accordingly, the terms along," lying along, and positioned against as used herein'mean closely adjacent to the refractory wall.

A feed water inlet 27 is disposed in the rear wall 12 for delivering feed water to the rear water leg 24, which in turn, distributes it to the side mud drums 25, from whence it circulates upwardly through the side water tubes 26 into the water shell 14. The steam is released in the upper chamber of the water shell 14 and expelled through the steam main flange 28 for subsequent distribution, the remaining water circulating back to the side mud drums.

The water tubes 26, preferably of the seamless tubing construction, receive heat radiation and reflection from the refractory walls 13 thereby increasing the circulation which increases the efficiency of the inner-tubular surfaces, preventing by a greater or less degree the formation of deposits thereon. Better circulation adds durability to the boiler, by keeping all parts at a nearly uniform temperature preventing unequal strains in the boiler structure. Better circulation also improves the economy, increases the capacity, reduces the necessity to clean frequently, and results in safer operation of the boiler.

The fire travels from underneath the lower shell portions 17 towards the rear of the boiler upwardly into the area defined by the rear partition wall 21, the horizontal wall 23, and the rear closing wall 22 of the lower circular portions 17. From there, the fire enters a lower group of horizontal fire tubes 29, which are disposed within the lower semi-cylindrical portion 17 of the boiler shell lying substantially parallel with the refractory side walls 13 and with each other, and being supported between the front wall 11 and the rear semi-circular wall 22. The fire then passes forwardly through the fire tubes 29 and into a front smoke box 30 upwardly into an upper group of fire tubes 31, which are horizontally positioned in parallel relationship within the upper semi-cylindrical cover 16, passing backwardly towards the rear of the boiler to a rear smoke box 32 and outwardly to the breaching (not shown) and the chimney. out doors 33 which provide access, for inspection and cleaning purposes, to the smoke box and the upper and lower groups of horizontal fire tubes.

A safety valve flange 34 is positioned atop the water shell for the purpose of mounting a suitable safety valve.

A second embodiment of the invention is illustrated in Figures 3, 4 and 5, wherein the vertical tube arrangement is utilized with a modified type of boiler.

In Figure 3, it is seen that the water shell, generally designated as 35, includes an elongated outer inverted U- t1."

shaped casing or upper crown sheet 36 extending between a vertical front wall or boiler head 37 and a vertical back wall or boiler head 38, being welded or fastened thereto by other suitable means. An inner inverted substantially U- shaped elongated member 39 is disposed within the member 36, but spaced therefrom, and extends from the front wall 37 terminating at a point inwardly from the rear wall 38. Short horizontal members or lower crown sheets 40 contend with said inner member 39 and directly bridge The front smoke box 30 carries flue clean 4 portions of the boiler shell thereby defining within these portions a fluid chamber.

A fire box 41 lies below the boiler shell being enclosed by the front wall 37 and the back wall head 38, and by opposite refractory side walls 42. Again the fire box may be fired in the conventional manner.

A vertical partitioned wall 43 spaced inwardly from the front boiler head 37 and in parallel relation thereto defines therebetween a front water leg 44, which intercomniunicates the legs of the inverted U-shaped boiler shell 35 and a pair of lower longitudinally disposed side mud drums 45 adjacent the front of the boiler. Connecting the lower side mud drums at the rear of the boiler with the boiler shell is a vertical rear boiler leg 46 defined by the rear boiler head 38 and an inwardly spaced partition 47. A suitable feed. water inlet conduit 48 is disposed in the rear boiler head 38 adjacent its lower end. Access to the fire box 41 is had through the fire door 49 positioned in the front boiler head 37 and extending through the front water leg 44. The front and rear water legs are closed at their lower ends by appropriate bottom members.

Vertical water tubes 50, preferably of seamless steel, are positioned along or against each refractory side wall 42 in parallel spaced relationship, connecting the lower side mud drums 45 with the legs of the water shell 35 through the lower crown sheets or members 40. These vertical water tubes function in the same manner as described with the preferred embodiment of the invention, and in this instance where the boiler is of substantially conventional construction, the water tubes may be installed to increase the efficiency of the boiler.

Adjacent the rear of the boiler, but spaced from the rear water leg 46, is a lower transverse mud drum 51, of generally rectangular shape, interconnecting the water flow between the opposite side mud drums 45. Positioned directly above the drum 51, and in parallel and axial alignment therewith is an upper mud drum 52, which is likewise spaced substantially from the rear water leg 46, and it intercommunicates the legs of the U-shaped boiler shell 35. The upper and lower transverse mud drums 51 and 52 extend through the refractory walls 42, for purposes of providing access therein through clean out plugs 53. Another bank of vertical water tubes 54, disposed transversely of the boiler, intercommunicates the lower mud drum 51 and the upper mud drum 52 and separates the fire box from the boiler shell flue, thereby necessitating the fire to travel around said tubes.

In this embodiment, horizontally extending water tubes 55 connect the front water leg 44 near the boiler shell and the upper drum 52, while shorter rear horizontal water tubes 56 extend between the upper drum 52 and the rear water leg 46 directly below a flue 57 defined by the U-shaped water shell 35. Clean out plugs 58 are positioned in the front boiler head 37 providing access to clean the water tubes 55, while clean out plugs 59 received in the rear boiler head 38 provide access to the shorter rear horizontal water tubes 56.

As shown in Figures 3 and 5, the flue 57 is open at its lower end and communicates directly with the fire box. However, it is closed by a baflie 60 formed of fire brick or other suitable refractory brick, except for a short space .61 (Figure 5) at the rear of the boiler. This space is also closed partially by the upper mud drum 52.

It will therefore be necessary for the flames in the fire box to pass to the rear thereof, then upwardly through the opening 61, forwardly through the flue 57 into a front smoke box 62, and backwardly through a group of horizontally disposed fire tubes 63 within the boiler shell 35 to a rear smoke box 64. From the rear smoke box 64, the fire will then pass through conventional breaching (not shown) to the chimney. A flue cleanout door 65, removably secured to the front smoke box 62, is provided for access to the horizontal fire tubes 63, and may be supported thereto by any suitable means.

It is characteristic of the boiler constructed according to this invention that ditferent parts may be stamped from suitable sheet steel and quickly assembled as by welding, riveting, or other means.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concept of the present invention.

I claim as my invention:

1. A boiler which comprises a front wall, a back wall, refractory side walls defining a rectangular fire box, an inverted substantially U-shaped water shell overlying said fire box, a plurality of horizontal fire tubes within said shell, side mud drums paralleling said side walls and being substantially spaced below said shell, a lower transverse mud drum intercommunicating said side mud drums intermediate their ends, an upper transverse mud drum spaced above said lower transverse drum in parallel alignment therewith, said upper transverse drum intercommunicating with the legs of the U-shaped shell, a group of vertical water tubes intercommunicating the upper and lower transverse drums, and a plurality of vertical water tubes intercommunicating the side mud drums and the shell.

2. A boiler which comprises a front wall, a back wall, refractory side walls defining a rectangular fire box, an inverted substantially U-shaped water shell overlying said fire box, a plurality of horizontal fire tubes within said shell, side mud drums paralleling said side walls and being substantially spaced below said shell, a lower transverse mud drum intercommunicating said side mud drums intermediate their ends, an upper transverse mud drum spaced above said lower transverse drum in parallel alignment therewith, said upper transverse drum intercommunicating with the legs of the U-shaped shell, a group of vertical water tubes intercommunicating the upper and lower transverse drums, a plurality of vertical tubes intercommunicating the side mud drums and the shell, front and back water legs defined by the front and back walls and inwardly spaced partitioning means, a plurality of horizontal water tubes intercommunicating said front water leg and said upper transverse drum at the top of said fire box and a plurality of horizontal water tubes at the top of the fire box intercommunicating said back water leg and said upper transverse drum. t,

3. A boiler construction comprising a water shell having an inverted U-shaped wrapper sheet, an inverted U-shaped top crown sheet centrally within the wrapper sheet in spaced relation from both the bight and legs of the wrapper sheet and horizontal lower crown sheet portions directly connecting the bottoms of the legs of the crown sheet with the legs of the wrapper sheet, said wrapper sheet, crown sheet, and horizontal lower crown sheet portions defining an inverted U-shaped water chamber with a central flue along the length thereof, vertical water tubes depending at spaced intervals along the length of the water shell directly from each of the horizontal crown sheet portions and providing a vertical row of tubes on each side of the water shell extending below the shell, an elongated mud drum under each row of vertical tubes receiving the tubes directly in the top thereof, refractory side walls between the mud drums and bottom of the water shell beyond said vertical tubes, said side walls defining a fire box space therebetween under said water shell and containing said vertical tubes, front and back heads closing the ends of the water shell and fire box space, a horizontal bafile extending from the front head between said flue and fire box space into spaced relation with the back head for directing gases from the fire box space under the flue to the rear of the fire box space and then allowing the gases to rise into the flue, a bank of upright water tubes extending across the fire box space at the end of the bafile spaced from the back head in the path of gas flow to the flue, a smoke box at the front head receiving gases from the front of the flue, fire tubes extending through said water chamber receiving gases from the smoke box whereby water in the Water shell and in the water tubes is efficiently heated and circulated with minimum flow restriction and heat loss.

References Cited in the file of this patent UNITED STATES PATENTS 771,290 Worthington Oct. 4, 1904 1,593,600 Ross July 27, 1926 1,677,427 Bean July 17, 1928 1,832,311 Lockett et a1. Nov. 17, 1931 1,925,026 Austin Aug. 29, 1933

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