US3175540A - Hot water boiler - Google Patents

Description

March 30, 1965 M. DUBIN ETAL HOT WATER BOILER 2 Sheets-Sheet 1 Filed Dec. 13, 1961 ATTO RNEY wk v. m wm W 3 m u 2 WDMWT a m m w n mmmfi Mmnm m m w M w x w 8 L LL his C, a 2 m i H \E n 1| 1 I. ll 9 W g m 1 3 H x 44H I I I l l I l ll Ill l|I.l|\ A] i L H 1. 2 5 M M a M i m G .1 a 4 S u l W G 2 w F M REUEF VALVE March 30, 1965 M. DUBlN ETAL HOT WATER BOILER 2 Sheets-Sheet 2 Filed Dec. 13, 1961 FIG. 7 1; I

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m MN 0 v T Em MM Y A. NN V. 0| E 2 U T R 5 O W T MG T A "mm M NV ER Bl United States Patent 3,175,540 HOT WATER BOILER Melvin Dubin, New York, and Milton Gordon, Levittown, N.Y., Benjamin Ronn, Palisades Park, N.J., and Isidore Turinsky, North Babylon, N.Y., assignors to Slant/ Fin Radiator Corporation, Richmond Hill, N.Y., a corporation of New York Filed Dec. 13, 1961, Ser. No. 159,129 7 Claims. (Ci. 122-230) The present invention relates to boilers, particularly intended for central heating in circulating hot-water systems but having additional applications.

From the point of view of fuel economy, it is desirable that a furnace should have a boiler that effectively extracts all the heat available in the combustion gases. Carried to a limit, this could lead to immense boilers of elaborate construction. However, the boiler installation should conserve space and therefore a boiler of minimum size is desirable, consistent with etficient heat extraction as evidenced by low temperature of the discharged fluegas, and consistent with the rated heat-extraction capacity, that is, the amount of heat per hour that can be delivered to the heating system. Minimum cost is also desirable and this, in turn, is related both to the amount of material required and to the character of the manufacturing operations required by the form of the boiler.

An object of this invention resides in the provision of a novel form of boiler that combines high efliciency with compactness, for given rated capacity. A further and important object of the invention resides in the provision of an efficient and compact boiler that is of a novel configuration providing extensive heat-exchange wall area from the combustion-gas passages to the water space, without resort to shapes or designs which would necessitate costly or exacting manufacturing methods. With particular concern for circulating hot-water heating systems, an object of the invention resides in provision of a novel form of boiler and combines the foregoing features with provision of an extended length of path of the water through the heat-exchange unit.

Hot water boilers for heating systems are generally made of cast-iron; and in order to provide extensive heat-exchange surfaces, elaborate shapes have been devised involving cavities that can be fashioned only by resort to cores in the casting process. Such a design has the efifect of increasing the cost of the castings, and of allowing undue wall thicknesses so as to take into account the limitations of the manufacturing methods, notably the variations in positioning of the casting molds and cores. Excess wall thickness increases both the cost and the weight of the cast-iron used, and it also increases the wall thickness through which the heat must travel from the combustion-gas passages to the water. It is a feature of the novel heat-exchange unit provided by the present invention that a minimum of wall thickness can be attained without resort to special casting methods.

The foregoing and other objects of the invention are achieved in the illustrative embodiment and a modification that are described in detail below and are shown in the accompanying drawings. The preferred embodiment shown utilizes a pair of cast walls that incorporate relatively numerous passages of large surface area exposed to the hot combustion-gases and correspondingly numerous water spaces for extracting the heat. Casting cores are not needed in making the walls, which are sealed to each other. Despite the extensive heat-exchange area provided by formations in the walls, the two walls are joined to each other only at their periphery. The joint is especially easily made and reliable in service when it is in the form of a circle. The walls have tapered 3,175,540 Patented Mar. 30, 1965 complementary circular sealing rims in the embodiment described below. Such rims may be cast to a high order of precision without inordinate expense, and a circular tapered rim can be readily machined for ideal complementary fit, even to the extent of producing a wa ter-tight seal without resort to sealing compounds.

The illustrative embodiment of the invention includes elongated zig-zag combustion-gas passages that alternate, horizontally, with elongated vertical zig-zag water spaces; and by proper arrangement of the water inlet and water outlet sections of the boiler and interconnection of the various water spaces, remarkably efficient and effective boiler performance is attained. For directing the flow of water through the heat-exchange unit, reliance is placed not only on the formations in the cast-iron walls of the heat-exchange unit, but in addition there is provided a series of water-space dividers that have ears by which the dividers are resiliently centered in the respective water spaces. The dividers are simply deposited in the respective water spaces, before the two walls are assembled together, and they retain their intended positions without resort to special fastening means and without resort to special mounting or sealing devices for the dividers.

The nature of the invention, and its further objects, novel features and advantages will be more fully apparent from the following detailed description in which reference is made to the accompanying drawings which form part or" the present disclosure.

In the drawings:

FIG. 1 is the perspective of a hot water boiler;

FIG. 2 is a vertical section through the boiler of FIG. 1, as viewed from the line 2-2 in FIG. 6; H

FIG. 3 is an enlarged fragmentary perspective view of a component in FIG. 2; g

FIG. 4 is a horizontal cross-sectional view at the plane 4-4 of FIG. 2;

FIG. 5 is an exploded perspective, partly in crosssection, of certain components in FIGS. 2, 3 and 4;

PEG. 6 is a vertical cross-section of the boiler in FIGS. 1, 2 and 4, as viewed generally from the line 66 in FIG. 2; and

FIG. 7 is a horizontal cross-section of a modification, viewed corresponding to FIG. 4.

FIG. 1 shows the exterior of a hot-water boiler of a form that is suitable and intended for central heating of a home by circulating hot water, as an illustrative application of various features of the present invention. The sheet-metal exterior 10 completely encloses the heatexchange unit and a gas burner, the walls of sheet-metal enclosure 10 being suitably insulated internally, as by rock-wool. Combustion gas may be supplied at gas-pipe 12, and the flue gas emerges via chimney pipe 14. .Water returns from the heating system and enters the boiler at inlet pipe 16. Heated water leaves the heat exchan'ge unit for recirculation via outlet pipe 18. Another pipe 20 is shown, suitable for a temperature gage, a pressure gage, a pressure-relief valve, and any combination of these devices and others in conventional heating'installations.

In FIGS. 2, 4 and 6, the boiler 22 is shown, certain important components being shown in FIG. 5. Below the heat-exchange unit is a gas burner 23, divided into two sections as shown in FIGS. 2 and 4. Heat-exchange unit 22 includes two one-piece seamless walls 24 and 26 of cast-iron that are joined together by a circular seal 28 formed by complementary circular rims integral with walls 24 and 26, with an appropriately tapered portion 28a. Walls 24 and 26 together form a generally cylindrical or barrel-shaped unit with a horizontal axis.

In FIGS. 4, 5 and 6, wall 24 is seen to include formaears 46 provide lateral plates 60 48 extend to" the floor and provide vertical tions providing four vertical zig- zag passages 30a, 30b, 30c and 30d for the burning of hot combustion gases,

or fiue gases. At the horizontal extremes, diametrically, at the left and right of walls 24 and 26 as shown in FIG. 5, are water-containing sections 32 and 34 at the inlet and the outlet portions of the heat-exchange unit. These may-be considered to be inlet and outlet water manifolds, distributing the water to different devices at the inlet and collecting water from dilferent levels at the outlet side of the heat-exchange unit.

The formations in wall 24 between combustion- gas passages 30a, 30b, 30c and 30d, namely formations 36a, 36b and 36c,"constitute vertical 'zig-zag water spaces. Referring to FIG. 4, formations 36a, 36b and 360 are shown in horizontal cross-section, and appear as loops that are directed outward relative to the internal water space. In this same horizontal cross-section, loops 38a, 38b, 38c. and 38d are directed inward, relative to the water-containing space within walls 24 and 26.

The two walls 24 and 26 are essentially mirror-images of each other, disregarding such details as the complementary formations that form circular seal 28. Accordingly, walls 24 and 26 have aligned inwardly directed loops 38a, 38b, 38c and 38d, and correspondingly these Walls 24 and26 have alignedoutwardly directed loops 36a, 36b and 360.

Within loops 36a, 36b and 360 of both walls 24 and 26 are three vertical zig-zag dividers 40a, 40b and 400 of sheet-metal, preferably stainless steel. Each of these sheet-metal members 40 has a series of. cut-outs, with 7 resulting edges 42 and legs 44, and each leg has opposite ly directed ears 46. The respectivedividers 40 are centered in the corresponding vertical zig-zag water passages of formations 36a, 36b and 36c by virtue of the bent ears 46; andlegs 44 insure substantial spacing between the edges 42 of the dividers and the extremities of the outward directed loops 36a, 36b and 3'60. Legs 44 and yielding or resilient locating supports for the dividers Before the two walls are assembled, the dividers are dropped into place in one wall. After the walls are assembled, cars 46 engage the converging sur- I faces ofthe outward loops to hold the dividers in position resiliently after the two walls are assembled.

, A pair of vertical end plates 48 form lateral walls for ,the combustion- gas passages 30a, 30b, 30c and 30d.

Flanking these end plates and aligned with the peripheral edges of walls 24 and 26 are clamping rings 50. Tie rods 52 (threaded at their ends and provided with nuts) hold vertical zig-zag combustion-gas passages for delivery'to the flue-pipe 14, and ribs 56 provide abutment ledges for direct the hot gases from burners 23 to the vertical zigzag passages. I Plates 60 and hoodfi58 extend horizontally all the way from one plate 48 tothe other. These plates support for the heat-exchange unit. However, plates48 are exposed to'the hot combustion gases .and, both for efiicient opera 'tion and for insuring a cool exterior for enclosure 10, an

appropriate amount of heat insulation such as rock'wool '62 lines the internal surface of sheet-metal enclosure V opposite plates 48, and elsewhere.

.-rings 50, vertical plates 48, and boiler- walls 24 and 26 in assembly as illustrated. Ribs 54 provide abutment .ledges'for a hood 58 that guides the flue gases from these which form a bottom fire chamber and a supply of domestic hot water.

16, ordinarily the return line of a circultaing hot-water heating system. 7 Section 32 is of substantial vertical extent (note particularly FIG. 5) and acts as an inlet manifold to spread the inlet water up and down to various levels before the water starts to cross through the boiler to the outlet manifold section 34 and outlet line 18. Between sections 32 and 34, the 'water is caused to follow horizontal zig-zag pathsyas represented by the curved arrows in FIG. 4. The relationship between the combustion-gas passages and the water flow as described results in remarkably effective and efiicient extraction of heat from the combustion gas and transferred to the hot water system. The temperature of the discharged flue gas is but little higher than that of the water at the oulet line 18. In a pracical example of such a boiler, a heat-exchange unit having walls 24 and 26 approximately 20 inches in outside diameter by 13 inches in axial length has been shown in tests to yield an output of 80,000 Btu. per hour at efficiency. Accordingly, the device shown is both compact and highly eflicient, and is well suited to use in central heating systems.

The heat-exchange unit is of a construction that lends itself readily to low-cost manufacture. As seen in FIG. 4 particularly, each of thewalls 24 and 26 has surfaces everywhere that have a'minimum casting draft-angle so as to be well suited to simple casting methods without resort to costly special cores or the like. This is true of the inside and outside surfaces of both walls, and is true even of ribs '64. Nevertheless, and particularly in view of the remarkably intimate heat-transfer relationship between the vertical zig-zag gas passages and the horizontal zig-zag water passages, no more than a single 'sirnplecircular water-seal is involved in joining the two walls 24 and 26 together. Tapered surfaces 28a may have a machined finish, which is particularly easy to provide where the seal is circular. It has been found practical to assemble walls 24 and 26 together without requiring a sealing compound. Even where sealing compound is desired, the water seal involved in the illustrated walls 24 and 26' of the same general shape as that in FIGS. 2, 4, 5 and 6, with a modified seal 28' and modified divider plates 46'. The configuration in FIG. 7 is significant in that it incorporates a hot water heating tank 66. The apparatus in FIG. 7 is thus adapted to serve not only in a circulating hot-water heating system, but also to provide domestichot water. Separate inlet and outlet connections are provided for the two water spaces at the opposite sides of tank 66. It will be understood, of course, that unit 66 has appropriate cold-water inlet and hot-water outlet lines (not shown). It will also be understood that the boiler of FIGS. 2, 4, 5 and 6 may be equipped with a conventional tankless coil for providing a Because unit 66 as shown forms a complete barrier across the water-container, two water paths exist, and two sets of pipes 16, 16' at the inlet and 18, 18' at the outlet are provided Where greatly increased capacity is desired, the units illustrated in the drawings maynot only be increased in size for greater heat-exchange surface area, but additional boilers 22 may be assembled in axial alignment. In that event, a fiue-gas'passage 30 of one unit would be aligned with a like flue-gas passage 30 of thenext axially aligned heat-exchange unit; and consequently, no intervening plate 48 would be used at such confronting flue-gas passages except, possibly, for providing support.

occur to those skilled in the art, in light of the foregoing disclosure. Consequently, the inventionshould be broadly construed in accordance with its full spirit and scope.

What is claimed is: i i

1. A hot-water boiler, including a pair of confronting walls having aligned sealing rims, said walls together defining a water-containing space and having water-inlet and water-outlet connections, each of said walls having inward and outward extending corrugations therein providing multiple outside vertically continuous zig-zag fluegas spaces alternating horizontally with multiple inside vertically continuous zig-zag Water spaces, each said zigzag water space being approximately equal to each said zig-zag flue gas space when viewed in transverse crosssection, the corrugations of said pair of walls having a combined depth when measured along a horizontal line from one of said walls to the other that is substantially greater than half of the maximum horizontal extent of the water-containing space between said walls when measured along said line, said outward extending corrugations of each wall being coplanar, andmeans engaging said coplanar formations for laterally closing off said flue gas spaces.

2. A hot-water boiler, including a pair of confronting walls, said walls together defining a water-containing space and having water-inlet and water-outlet connections, each of said walls having inward and outward extending formations therein providing multiple outside vertically continuous zig-zag flue-gas spaces alternating horizontally with multiple inside vertically continuous zig-zag water spaces, said outward extending formations of each wall being coplanar, means laterally engaging said outward formations for laterally closing off said flue-gas spaces,

the transverse cross-section of each said flue-gas space being at least approximately equal to that of each said zig-zag water space, and the formations of said pair of walls having a combined extent when measured along a horizontal line from one of said walls to the other that is substantially greater than half of the maximum horizontal extent of the water-containing space between said walls when measured along said line, and vertical zig-zag sheet-metal dividers in a plurality of said vertical zig-zag spaces, said walls and said dividers forming horizontal zig-zag spaces interconnecting said divided vertical zig-zag water spaces.

3. A hot-water boiler, including a pair of confronting walls having mating tapered circular sealing rims, said walls together defining a water-containing space and having water-inlet and water-outlet connections, each of said walls having inward and outward projecting formations therein providing multiple outside vertically continuous zig-zag flue-gas spaces alternating horizontally with multiple inside vertically continuous zig-zag water spaces, each said zig-zag water space being approximately equal to each said zig-zag flue-gas space when viewed in transverse cross-section, the formations of said pair of walls having a combined extent when measured along a horizontal line from one of said walls to the other that is substantially greater than half of the maximum horizontal extent of the water-containing space between said walls when measured along said line, said inward and outward projecting formations of each of said Walls being disposed at opposite sides of a respective vertical plane.

4. A hot-water boiler, including a pair of confronting walls having aligned sealing rims, said walls together defining a water-containing space and having water-inlet and water-outlet connections, each of said walls having outward and inward formations therein disposed alternately at opposite sides of a vertical plane providing multiple outside vertically continuous zig-zag flue-gas spaces alternating horizontally with multiple inside vertically continuous zig-zag water spaces, said zig-zag water spaces and said zig-zag flue-gas spaces being substantially equal when viewed in transverse cross-section, said formations of said pair of walls being greater in extent when measured along a horizontal line from one of said walls to the other than half of the extent of said watercontaining space between said walls when measured along that line, each said wall having sloping surfaces providing a forming draft-angle throughout in opposite directions relative to said sealing rims.

5. A hot-water boiler, including a pair of confronting walls having aligned sealing rims, said walls together defining a water-containing space and having water-inlet and water-outlet connections, each of said walls having formations therein providing multiple outside vertically continuous zig-zag flue-gas spaces alternating horizontally with multiple inside vertically continuous zig-zag water spaces, said zig-zag water spaces and said zig-zag flue-gas spaces being approximately equal when viewed in transverse cross-section, the formations of said pair of walls having a combined extent when measured along a horizontal line from one of said walls to the other that is substantially greater than half of the maximum horizontal extent of the water-containing space between said walls when measured along said line, said formations of each of said walls extending outward to a respective common plane, and a plate against the outward extending formations of each of said Walls, respectively, laterally closing off said flue-gas spaces.

6. A hot-water boiler, including a unitary seamless heat-exchange wall having formations affording a series of vertically continuous flue-gas spaces separated by vertically continuous zig-zag water-containing spaces whose cross-section approximates that of the flue-gas spaces, the horizontal cross-section through said formations presenting a series of connected loops extending alternately outward and inward relative to the water-containing space and the outward extending formations being coplanar, the flue-gas spaces being constituted by the spaces between said outward loops, means confronting the successive inward loops but spaced therefrom by less than the inward-to-outward extreme portions of said formations, and said last-named means having a tapered circular rim sealed to a complementary peripheral edge of said heatexchange wall, said last-named means providing a confronting wall for said heat-exchange wall, and means laterally engaging said coplanar outward extending formations for laterally closing off said flue-gas spaces.

7. A hot-water boiler, including a generally barrelshaped heat-exchange unit disposed with its axis extending horizontally and having two confronting individually seamless heat-exchange walls having complementary tapered circular rims and sealed to each other only at said rims, said walls together defining a water-containing space and having water-inlet and water-outlet connections, each of said walls having inward and outward extending formations therein providing multiple outside vertically continuous zig-zag flue-gas spaces alternating horizontally with multiple inside vertically continuous zigzag water spaces, said zig-zag water spaces and said zigzag flue-gas spaces being approximately equal when viewed in transverse cross-section, said formations of said pair of walls having a combined extent when measured along a line extending horizontally from one of said walls to the other that is substantially greater than half the horizontal extent of said water-containing space between said walls when measured along said line, said outward extending formations of said walls extending to a pair of vertical planes, respectively, and a pair of plates laterally closing off said flue-gas spaces and engaging said outward extending formations, respectively, said plates being secured to said walls and extending below said walls and constituting supporting means for said walls.

(References on following page) References Cited by the Examiner UNITED STATES PATENTS Lapp 122-228 Dickinson 122-227 5 Gieseler 122-367 X Sharp 122-210 Jungers 122-225 Ofeldt 122-408 X FOREIGN PATENTS 3/26 France; I

1/ 29 Great Britain. 9/40 Great Britain.

PERCY L. PATRICK, Primary Examiner. Franzheim 122-210 10 FREDERICK L. MATTESQN, JR., Examiner.

Claims (1)

1. A HOT-WATER BOILER, INCLUDING A PAIR OF CONFRONTING WALLS HAVING ALIGNED SEALING RIMS, SAID WALLS TOGETHER DEFINING A WATER-CONTAINING SPACE AND HAVING WATER-INLET AND WATER-OUTLET CONNECTIONS, EACH OF SAID WALLS HAVING INWARD AND OUTWARD EXTENDING CORRUGATIONS THEREIN PROVIDING MULTIPLE OUTSIDE VERTICALLY CONTINOUS ZIG-ZAG FLUEGAS SPACES ALTERNATING HORIZONTALLY WITH MULTIPLE INSIDE VERTICALLY CONTINUOUS ZIG-ZAG WATER SPACES, EACH SAID ZIGZAG WATER SPACE BEING APPROXIMATELY EQUAL TO EACH SAID ZIG-ZAG FLUE GAS SPACE WHEN VIEWED IN TRANSVERSE CROSSSECTION, THE CORRUGATIONS OF SAID PAIR OF WALLS HAVING A COMBINED DEPTH WHEN MEASURED ALONG A HORIZONTAL LINE FROM ONE OF SAID WALLS TO THE OTHER THAT IS SUBSTANTIALLY GREATER THAN HALF OF THE MAXIMUM HORIZONTAL EXTENT OF THE WATER-CONTAINING SPACE BETWEEN SAID WALLS WHEN MEASURED ALONG SAID LINE, SAID OUTWARD EXTENDING CORRUGATIONS OF EACH WALL BEING COPLANAR, AND MEANS ENGAGING SAID COPLANAR FORMATIONS FOR LATERALLY CLOSING OFF SAID FLUE GAS SPACES.

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