US2408968A - Boiler construction - Google Patents

Description

@Ct- 3 1946. R. c. cRoss n I BOILER CONSTRUCTION Filea April 7, -1944 3 Sheets-Sheet 1 .ani

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R C CROSS BOILER- CONSTRUCTION Filed April 7,'1944 S MN 0d 89 194s. R. c. cmss y 2,408,968

A BOILER CONSTRUCTION Fiied April 7. 1.944 5 sheets-sheet s Patented ct. 8, 1946 BOILER CONSTRUCTION Robert C. Cross, Riverside, Ill., assignor to Sears, Roebuck and Co., Chicago, Ill., a corporation of New York Application April 7, 1944, Serial No. 529,986l

2 Claims.

The present invention relates to improvements in the construction and design of radiation heating boilers for use in either steam or hot water systems to be red by means of oil or gas burning devices.

A principal object is to achieve a more compact design to be operated for producing more eniciently the circulation of the heating medium, while attaining esthetic results in the over-all outline of the boiler assembly under various arrangements of boiler 'sectional composition.

In the construction of heating boilers for use in steam o-r hot water systems, it has been known to provide intermediate sectional units which may be varied in quantity so as to accordingly regulate the capacity of the boiler according to specific requirements.

In the herewith proposed apparatus it is a further object to utilize a cast iron sectional boiler construction for oil or gas burning heater systems in which the variable sections are provided with staggered lwater tubes so as to break up the combustion flue stream with inclined section elements that effect an eilicient heat exchange medium while inducing a free natural water flow from the rear to the fore portions of the assembly.

In order to achieve the objects declared above, there is herewith proposed a boiler design incorporating the features of interchangeable multiple section assembly in which each section is constituted of upper and lower header portions connected by staggered and inclined water tubes of tear-drop cross-section so as to insure the rapid and eiiicient flow of Water in'the boiler, and to utilize to a maximum degree the natural ilow of heated flue gases in order to effect a thorough heat exchange by conduction, to expose a minimum top surface to the accumulation of soot deposit which tends to create a heat deterrent and insulation, and to achieve these and other eniciency motives while maintaining an over-all graceful and pleasing contour that lends itself to facile jacketing and artistic enclosure.

For a better understanding of how the foregoing objects are attained and the details concerning the constructional features of this apparatus, reference will now be had to the accompanying drawings and to the following detailed speciiication in which like reference characters designate corresponding parts throughout and in which:

Fig. l is a front elevation of a boiler embodying the characteristics of this invention with an illustrative jacketing structure in section;

Fig. 2 is a plan sectional View of the boiler illustrated in Fig. l., taken approximately on line 2--2 thereof;

Fig. 3 is a vertical sectional view of the apparatus featured in Figs. 1 and 2, taken approximately on the line 3-3 of Fig. 2;

Fig. 4 is a fragmentary vertical sectional view enlarged taken at one corner of the sectionalized boiler construction as indicated on line 4-4 of Fig. 2;

Fig. 5 is a vertical sectional View of the boiler construction featured in the foregoing figures and taken on a line indicated 5-5 on Figs. l and 2, indicating an oil burner device and exhaust .pipe attached;

Fig. 6 is a Vertical elevational view of a modied boiler construction embodying the features of the present invention for use with a gas burning heat element;

Fig. '7 is a detailed perspective View of a flanged control receptacle tting adapted for use with a heating boiler embodying 'the features of the present invention.

Fig. 8 is a detailed perspective View of an exemplary boilei` sectional unit with portions of .the inclined connecting flues broken away to indicate their conformation; and

Fig. 9 is a plan View of the boiler section featured in Fig. 8, having portions broken away to reveal the construction of the lleted flue junctures.

Referring now more particularly to the accom-- panying drawings, the reference character l designates a combustion chamber or base casting designed for use in conjunction with an oil burning chamber. This member is ywater jacketed as at 2 on its vertical sides and on the bottom, a lining of fire clay or other refractory material shaped to produce the desired flame convection, being provided to line the inner chamber of the base I and thereby constituting the combustion chamber which is disposed centrally and beneath the water tubes 6 which will be discussed in greater extent later. The upper edges of the surrounding Vertical wall sections of the base casting including a transverse jacketed front wall 2a are inclined with the fore portion at a higher ele- Vation, as best indicated in Fig. 5, than that of the rear portion, conforming in this respect to the angle of inclination oi the several intermediate sections 4 and 5 with respect to their forward and rearward header portions 1 and 8. The 'number of sections 4 and 5 which may be provided inthe assembling of each unit heating boiler will vary in accordance with; the heating capacity required by the specific installation problems. Alternate sections are preferably of identical design, while contiguous ones preferably differ from each other in respect to the nurnber and relative disposition of their water tubes E, as best indicated in Fig. 3. Specifically this arrangement provides for the displacement of the consecutive tubes at intervening points in vertical alinement `so that the heated gases rise and pass through the boiler sections where current deflections and eddy streams formed upon engaging the rounded lower surfaces of the several tubes 6 are broken up by the staggered arrangement of consecutive sections causing 'the air streams to be driven into closer contactual engagement and eiecting thereby a more complete transfer of heat from these gases to the tubular elements 6.

The sections 4 and 5 are otherwise of identical formation and each is provided with four corner push nipple openings that flare with a gradual taper in accordance with conventional boiler assembly practice, so that each with its adjacent section may be integrated to form a continuous passageway with the other internally by connection of push nipples 9 that are received in the nipple boss formations III. The lowermost section 5 is connected in a similar manner with the base casting I, while the uppermost section 4 is thus connected to an upper dome casting I2. In this way the entire water space of the dome, base, and intermediate sections is rendered continuous and the assembly, after being cemented for sealing, is clamped together by means of external draw bolts I8 which pass through dome section ears ISa and base section ears ISD, as clearly illustrated in Figs. 1 and 6.

As a result of the inclination in the water tubes 6 of the intermediate boiler sections, the water content is facilitated in rising in a direction from the rearmost part of the boiler unit to the foremost part, thereby constituting the primary factor in promoting a maximum eiiiciency circulation of this fluid internally of the boiler unit which makes for the proper mixing of cooler incoming or return fluid with the contentsof the unit and the introduction of maximum heated fluid at the fore portion of the dry pipe 24 when used as a water boiler. The dry pipe 24 is provided with upper surface perforations 25 after the manner of conventional boiler design practice, thus effectively providing a means of insuring the delivery of dry steam to a steam heating system; The pipe 24 also serves the purpose of insuring proper internal boiler circulation when used as a hot water boiler.

In addition to the aforedescribed control of internal water or steam circulation, a further design feature is provided which will be explained with particular reference to Fig. 9. There it will be noted that the water tubes 6 join their respective headers 1 and 8 forming at the point of juncture arcuate fillets having on the one hand major radius junctures as at 33 and opposite thereto minor radius junctures as at 34; As the flow of water from the lower to the higher header levels approaches the juncture, the tendency upon encountering major radius turns is to induce water circulation in that direction as against sharp turning in the direction of the minor radius 34. All of the tubes 6 are thus designed, save the central tube, in the case of a section having an odd number of flue pipes. The major radius fillets 33 cause the water flow from the pipes to be directed in a preferential current toward the outer extremity with reference to a median line paralleling the center ilue pipe. The general effect therefore is to induce clockwise and counter-clockwise current flow in each section in terms 5 of each half thereof with the aforedescribed median line as an intermediate boundary. This circulation control assures a lateral rotary movement in combination with the forward movement which is induced by the inclination of the water tubes 6.

The base casting I is provided with two water return embossments I4 toeither or both of which there may be connected the cold water return pipes from the circulating system depending upon the conveniences of a given installation. The water enteringr therethrough, being relatively colder, will become heated by conduction due to its exposure to the Walls of the fire box and as it is heated will rise within the boiler traveling through a course as above outlined, including the angularly disposed tubes 6 to the right or to the left of the vertical center of the boiler to be drawn into the system for circulation again through the header circulating pipe 25. In the case of a steam system, the heating of the return vapor will travel through a similar course as is well known in circulating heating systems.

Referring now again to the arrangement and disposition of the interchangeable boiler sections 5, attention is directed to the relatively narrow construction of the front or upper headers 1, as best indicated in Fig, 5, and by contrast therewith the flared and relatively wider construction of the rear or lower headers 8 which are provided with abutting rib formations 8a so as to form a continuous closed surface to that region of the boiler in contrast with the accessible openings Ia which intervene sections 1.

Clean-out door 35 indicated in both embodiments, Figs. 5 and 6, is particularly essential in the oil burning system to provide accessibility for removing soot deposits from the upper surfaces of the water tubes that may be reached by con ventional cleaning brushes by projecting them through the aforedescribed spaces 1a that intervene sections l'. In this way a maximum heating efliciency of the boiler sections may be maintained at all times, although the tear-drop cross-scctional design of the flues E affords a further advantage of minimizing heat exchange losses due to soot deposit insulation by reason of the fact that minimum surface areas are afforded to give support to such deposits.

Narrow spacing slots I6, Fig. 6, between the adjacent outer waterways I5, see also Fig. 3, may

be lled in with furnace cement or other ealking material whereby there is sealed the heating space which extends from the combustion chamber to the flue pipe 20 iitted on the flue pipe collar 2l.

No leakage losses result from the openings which face the clean-out door 35 during the time that this door is closed, and accordingly there is obtained an efficient leak-proof heat chamber that is nevertheless accessible for periodic cleaning purposes. At the inner end of the passageway,

which is co-extensive with cellar 2|, there are formed radial fins 22 which serve as a final means to absorb the heat from the outgoing gases, transferring it to the adjacent water space in the boiler 0 section I2. Similar rib formations may also be provided in the bottom surface Ia of the boiler section I2, which defines the ceiling of the combustion chamber and which lies just beneath the dry Pipe 24.

The dry pipe is preferably carried by a special pipe fitting 36, Fig. 7, which is secured to the boiler head by its bolted flange 3l and which is provided with a pair of horn formations 38 threaded to receive special immersion type fittings or si'rdevices, for example, pressure control a tus, safety valves or temperature regulators. The steam or water main supply line 2t is screw threaded into the body of the tting 35 in axial alinement with the dry pipe 24 and openings for similar header connections may be provided in one or two places as in the case of the return pipe embossments lil, depending upon specific requirements.

Fig. 5 indicates the location of an oil burner nozzle 2 with relation to the re box space and shows the manner in which this apparatus is projected through a front panel 28 of the base section i with the rear wall of the retort box appropriately curved to impart a rotary now of the heating flame from the nozzle 21 according to the curvature designated 29 in the lining material. An observation port having a protective glass window 3i? may be provided in the panel 23 through which may be seen the performance of the oil burner and draft movement imparted to its flame. An immersion type water heating unit 32 may also be provided to serve as a means for heating a domestic hot water supply system. rlhis type of heat exchange apparatus will perform most efficiently if maintained in contact with the hot water and below the steam boiler water line 3l at all times, as best indicated in Fig. 3.

To adapt this type of boiler for use with a gas burner, the interchangeable sections 4 and 5 and the same type of dome section l2 may be supported upon a modiiied base casing 40 provided with water jacket spaces el on all four sides, but preferably not on the bottom, after the manner illustrated in Fig. 6. Any conventional type of gas burner having perpendicularly directed jets, such as the element designated 42, may be utilized for this purpose, and an inlet arm 43 for supporting the burner and conveying gas supply thereto may be suitably mounted for support within this casting, or it may be carried by. means of leg brackets 44 which are associated with the base casting, as indicated in this gure. Both types of installations may be expected to perform more efciently when jacketed by an outer enclosure casing i5 spaced from the principal casting sections and insulated therefrom by appropriate heat insulation material such as rock wool, fibre glass, etc.

While the present invention has been explained and described with reference to but few specio illustrations, it is to be understood, nevertheless, that numerous variations and modifications may be invoked without departing from the essential spirit and scope thereof. Accordingly, it is not intended to be limited by the specic details of the accompanying illustrations, nor by the particular wording in the foregoing detailed description, except as indicated in the hereunto appended claims.

I claim:

1. A boiler section comprising a unitary casting affording higher and lower header sections, inclined ues connecting said header sections of tear-drop cross-section and having their small radius curvature uppermost, said nues being lleted at their point of junction with said higher header in non-symmetrical radii so as to present minimum iiow resistance to contained uid in a direction outwardly oi the transverse center oi said boiler section.

2. A boiler section comprising a casting of rectangular outline having a header at each end, alined push nipple orices in the top and bottom`walls of each header, for tier assembly with other sections, perimetric flues connecting said headers and having perimetric defining flanges, and intermediate flues connecting said headers lieted at their points of juncture with relatively larger radii in mean direction from the center flue outward and relatively smaller radii at each said points of juncture in opposite direction.

ROBERT C. CROSS.

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