US 3903868 A
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Description (OCR text may contain errors)
United States Patent 1 1 Salvo 1 Sept. 9, 1975 HOT WATER BOILER  Inventor: Anthony Salvo, 1219 Main Rd,
Tiverton, R1. 02873 221 Filed: Aug. 5, 1974 211 App]. No.1 495,128
 US. Cl. 126/361; 126/362; 122/37; 122/136 R  Int. Cl. H F2411 1/00  Field of Search 122/136 11.37; 126/361 126/362, 350 R  References Cited UNITED STATES PATENTS 8/1908 Mackley .1 122/161 1/1934 Brandt H 5/1936 Schumann 122/136 R 2.531 459 11/1950 Marshall Jr. 122/136 R FOREIGN PATENTS OR APPLICATIONS 1,526,932 1/1966 Germany 122/136 R Primary Emminer-Carroll B. Dority, 11'. Assistant Examiner-Larry l. Schwartz Attorney, Agent, or Firm-Salter & Michaelson 1 5 7 1 ABSTRACT A hot water boiler comprising an elongated cylindrical combustion chamber surrounded by an annular water jacket, said boiler comprising means for directing the flue gasses forwardly through said combustion chamber and then rearwardly along the outside of said water jacket whereby maximum heat transfer between said flue gases and water jacket is effected.
6 Claims, 4 Drawing Figures ABM-3,868
sum 2 of 3 HOT WATER BOILER BACKGROUND AND SUMMARY OF THE INVENTION The present invention relates generally to a hot water boiler of the type used in home or small industrial heating systems wherein water from the system is continuously circulated through the boiler and is heated thereby.
The basic and prevalent problem in connection with hot water boilers of this type is to obtain maximum output efficiency, i.e., maximum heating of the circulating water at a given combustion rate. Obviously, greater boiler efficiency results in a greater heating capacity for a given size boiler and at the same time minimizes fuel consumption, which in view of present energy shortages, is a highly important feature. While the conventional hot water boiler will normally have an output efficiency in the general range of 50 to 60%, it has been found that a hot water boiler constructed in accordance with the present invention normally has an output efficiency in the range of 90 to 92%.
It is therefore a primary objective of my invention to provide a hot water boiler that is highly effective for home and small industrial use; since, due to its relatively high efficiency, a relatively greater capacity of heating is obtained for a given fuel consumption rate. In addition, due to its relatively high efficiency, the boiler of the present invention may be of relatively small size, which is an obvious advantage from an installation standpoint.
Generally speaking, the above stated objectives are achieved by providing a boiler having an inner combustion chamber surrounded by an annular water jacket, the boiler being so constructed that the flue gases pass rearwardly through said combustion chamber and then are forced forwardly along the outside surface of the annular water jacket to a point of exhaust. Thus, the circulating water within the water jacket receives maximum heat transfer from the flue gases, since the path of the latter is such that not only is the inner surface of the annular water jacket contacted by said flue gases, but also the outer surface of the water jacket is in Contact with the flue gases during the return thereof.
Where greater heating capacity is required, it has been found feasible to exhaust the flue gases to a second water jacketed chamber through which the flue gases pass, and then return along the outside surface of the water jacket in the same manner as previously described.
Other objects, features and advantages of the invention will become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.
DESCRIPTION OF THE DRAWINGS In the drawings which illustrate the best mode presently contemplated for carrying out the present invention:
FIG. 1 is an elevational view, in section, of a hot water boiler comprising the present invention;
FIG. 2 is an elevational view, in section, of a modified form of boiler embodying the present invention;
FIG. 3 is a section taken on line 33 of FIG. 1; and
FIG. 4 is a section taken on line 4-4 of FIG. 2.
DESCRIPTION OF THE INVENTION Referring to the drawings, and more particularly to FIGS. 1 and 3 thereof, there is shown generally at 10 a hot water boiler comprising a cylindrical housing defined by cylindrical outer wall 12, front cover 14, and rear cover 16. As will be seen most clearly in FIG. I, outer cylindrical wall 12 actually comprises a steel shell filled with suitable insulation material 18, while the covers 14 and 16, also constructed of a structurally strong material, such as steel, are lined with heat insulating material, as shown at 20, 22 and 24. The cover members 14 and 16 are removably secured to cylindrical wall 12 by any suitable means, such as bolts 26.
Concentrically and axially positioned within outer wall 12, and extending from the inner surface of front cover 14, is a combustion chamber 28, said combustion chamber being surrounded by an annular water jacket 30. More specifically, water jacket 30 is defined by an inner steel cylindrical wall 32, which wall defines com bustion chamber 28, an outer steel cylindrical wall 34, and end walls 36, 38. It is important to note that water jacket 30 and hence combustion chamber 28 terminate short of rear cover 16. Expressed differently, end walls 36 of water jacket 30 are in spaced relation to the inner surface of insulating layer 24.
An inlet conduit 40 extends through front cover 14 into communication with water jacket 30 at a point closely adjacent to front cover 14. Conversely, outlet conduit 42 extends through front cover 14 and communicates with water jacket 30 at the location 44, which it will be noted is closely adjacent to rear cover 16. It will be understood that circulating water from the heating system continuously passes through conduit 40 into annular water jacket 30 and then exits through conduit 42 to again be circulated through the system.
Secured to rear cover 16, as by angle brackets 46, is an annular restrictor plate 48, constructed of a structurally strong material, such as steel, it being noted that said plate is located between and extends substantially parallel to annular wall 34 of water jacket 30 and the inner shell of outer cylindrical wall 12. It will further be noted that restrictor plate 48 terminates short of front cover 14. Adjacent to front cover 14, and extending through outer wall 12, is exhaust stack 50. It will be seen that the annular space located between restrictor plate 48 and the inner surface of outer Wall 12 is an unencumbered, substantially dead-air space which acts to further insulate the heated flue gases flowing along the inner side of plate 48.
Secured to the outer surface of front cover 14, by any suitable means, such as bolts 52, is a conventional burner 54 which may be fueled by oil and which comprises firing nozzle 56 extending through opening 58 in front cover 14.
In operation and use, and with burner 54 firing at any desired capacity, which normally will be in the range of 1.75 to 2.75 gallons per hour, the heated flue gases pass rearwardly through combustion chamber 28 following the direction of the arrows shown in FIG. 1. Upon reaching the end of chamber 28, the flue gases are forced outwardly and reverse their direction and pass forwardly between outside wall 34 of water jacket 30 and annular restrictor plate 48, it being understood that plate 48 physically forces and directs the flue gases against outside wall 34 during the reverse flight of said gases. Upon reaching the end of restrictor plate 48, the
flue gases are free to exit outwardly through stack 50, it being understood that a conventional draft associated with said stack will normally suck said flue gases outwardly therethrough. In the meanwhile, water from the system is continuously being fed into water jacket 30 by means of conduit 40 and then is recirculated back into the system by means of conduit 42. Maximum heat transfer between the flue gases and water jacket 30 is accomplished, because the flue gases not only engage inner wall 32 of the water jacket, but also engage outer wall 34 of the water jacket during the return flight of the flue gases, as hereinbefore described. It has been found that greater efficiency is obtained by exiting the heated water from water jacket 30 at location 44, since this insures that water exiting through conduit 42 will have been subjected to substantial heat transfer before departure from the boiler.
It has been found that the hot water boiler 10, as illustrated and described. will operate at an output efficiency of somewhere in the range of 90 to 92%. The boiler may be of relatively small size, and in actual practice a boiler having an overall length of approximately 5 feet 4 inches and an outer diameter of approximately 2 feet 3 inches has been found sufficient to effectively heat the average home. Where, however, greater capacity is required, it has been found possible to combine the boiler with a second, somewhat similarly constructed housing, shown generally at 60 in FIG. 2. The only difference between the housing 60 shown in FIG. 2 and the boiler 10 shown in FIG. 1 is the fact that the exhaust stack 50 has benn eliminated, and in place thereof a stack or chimney 62 carries the heated flue gases from boiler 10 to chamber 64, the construction of which, it will be understood, is basically the same as that of firing chamber 28. As will be clearly seen in FIG. 2, housing 60 comprises outer cylindrical wall 66 and front and rear covers 68, 70, all corresponding to like components in the boiler 10. Likewise, chamber 64 is surrounded by water jacket 72 defined by inner and outer wall 74, 76, and a restrictor plate 78 extends forwardly from rear cover 70, terminating short of chimney 62. In the form of my invention illustrated in FIG. 2, the outlet conduit 42 shown in FIG. 1 is eliminated, and in place thereof there is provided a transfer conduit 80 which circulates water from water jacket 30 and boiler 10 to water jacket 72 of housing 60. An outlet conduit 82 extends through front cover 68 and communicates with water jacket 72 adjacent the forward end of the latter. An exhaust stack 84 extends through outer wall 66 to carry off the flue gases.
In operation and use, burner 54 fires into chamber 28, and the heated flue gases follow the exact same path as described in connection with the form of my in vention illustrated in FIG. 1. However, after the flue gases have passed rearwardly along the outside surface 34 of water jacket 30, the flue gases pass upwardly through chimney 62 and then pass forwardly through chamber 64 and then rearwardly along the outside surface 76 of water jacket 72 and then are exhausted through stack 84. Meanwhile, circulating water from the heating system has entered water jacket 30 via conduit 40 and passes through said water jacket to transfer conduit 80, which then introduces the water into water jacket 72 of housing 60, from which the heated water exits via conduit 82 to once again pass through the heating system. It will thus be seen that the benefits derived from the form of my invention illustrated in FIG.
l are perhaps derived to an even greater extent in the form of my invention illustrated in FIG. 2, since the heated flue gases pass in series along the inside and outside of two separate water jackets, thus resulting in greater total heat transfer than in the embodiment of FIG. 1 where only one housing and water jacket are utilized. As previously stated, however, the form of my invention illustrated in FIG. 1 is sufficient for the heating of a normal home; whereas the form of my invention illustrated in FIG. 2 is beneficial where a somewhat greater capacity is required. Preferably, the housing is located above the boiler 10 and in registry therewith, as illustrated in FIG. 2, since such an arrangement takes advantage of the natural tendency of the heated flue gases to rise, whereupon the heated flue gases from boiler 10 will naturally pass upwardly through chimney 62 to chamber 64 of upper housing 64. It will also be noted that in the embodiment of my invention illustrated in FIG. 2 the preferred size of the boiler 10 and upper housing 60 is greater than that of the boiler 10 shown in FIG. 1. More specifically, in the form of my invention shown in FIG. 2, both the unit 10 and the unit 60 have performed satisfactorily where the overall length of each unit (from front cover to rear cover) is approximately 12 feet 8 inches and where the outside diameter of each unit is approximately 3 feet 9 inches. It will be understood, however, that the dimensions mentioned herein are in no way critical but merely are stated as being illustrative of the general size of working units embodying my invention.
Although not expressly emphasized hereinbefore, the flue restrictor plates 48 and 78 from an important part of my invention, because these plates restrict the reverse flow of the heated flue gases in such a way that the flue gases are forced against the outer surface of water jackets 30 and 72 in order to maximize heat transfer between the flue gases, during their reverse flow, and the respective water jackets. It will also be noted that the restrictor plates are maintained properly spaced from the adjacent water jacket outer surface by means of studs 86. Note also that a plate 88 may be provided between the front end of water jacket 30 and the inner surface of outer wall 12, as shown most clearly in FIG. 1. This plate functions not only as a support for the inner end of the water jacket, but also acts as a baffle to help deflect the flow of flue gases to stack 50.
While there is shown and described herein certain specific structure embodying the invention, it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited to the particular forms herein shown and described except insofar as indicated by the scope of the appended claims.
What is claimed is:
1. A hot boiler comprising a cylindrical housing defined by an outer insulated cylindrical wall having a front cover closing off one end thereof and a rear cover closing off the other end, an inner combustion chamber located within said housing and extending axially and concentrically thereof, said chamber extending from said front cover and terminating short of said rear cover, an annular water jacket surrounding said chamber, a cylindrical restrictor plate extending from said rear cover and terminating short of said front cover,
said restrictor plate being located between said water jacket and said outer wall and being spaced from each, said restrictor plate and said outer wall defining therebctween a dead-air insulation space an exhaust stack extending through said outer wall and outwardly therefrom and located adjacent said front cover, inlet and outlet conduits communicating with said water jacket whereby water is continuously circulated therethrough. an opening in said front cover. and burner means located outside said front cover and firing through said opening, whereby the heated flue gases are forced rearwardly through said combustion chamber, and then forwardly between the outside of the water jacket and the inside of the restrictor plate and then are exhausted out said stack.
2. In the boiler of claim 1, said inlet conduit making communication with said water jacket adjacent said front cover, and said outlet conduit making communication with said water jacket adjacent said rear cover.
3. In the boiler of claim 2, said exhaust stack being located adjacent said front cover.
4. In the boiler of claim 3, a second cylindrical housing constructed similarly to said first housing and mounted adjacent thereto, said outlet conduit interconnecting the water jackets of said first and second housings, said exhaust stack communicating with the inner chamber of said second housing whereby the flue gases from said first housing pass through the inner chamber of said second housing and then backwardly between the water jacket and restrictor plate of said second housing, outlet means communicating with the water jacket of said second housing. and stack means communicating with said second housing to exhaust the flue gases therefrom.
5. in the boiler of claim 4, said outlet conduit communicating with the water jacket of said second housing at a point adjacent the rear cover thereof, said outlet means communicating with the water jacket of said second housing at a point adjacent the front cover thereof, and said stack means being located adjacent the front cover of said second housing.
6. 1n the boiler of claim 5, said first and second housings being horizontally disposed, with said second housing being located above said first housing in registry therewith