US2553713A - Fuel combustion furnace - Google Patents

Description

May 22, 1951 w. B. LEVIS FUEL COMBUSTION FURNACE Filed March 2, 1948 2 Sheets-Sheet 1 .NVENTOR MQQN May 22, 1951 w. B. LEVIS FUEL COMBUSTION FURNACE 2 Sheets-Sheet 2 Filed March 2, 1948 Patented May 22, 1951 UNITED STATES PATENT OFFICE 2,553,713 FUEL consusmn FifaNAoE William B. Levis, rhiaaapta, Pa. Application March 2, 1948, Serial No. 12,532

v 3 Claims. 1

My invention relates to 'a fuel combustion furnace.

A purpose of my invention is to simplify the fabrication and increase the durability of fuel combustion furnaces.

, A further purpose is to provide a baflle type fuel'combustion furnace in which the heat trans- ;fer tubes extend immediately below the 'baifles,

and the ba'files preferably conform to the curvature of the tube bends.

A further purpose is to support the heat transfer tubes from the baffles, preferably by an interlock between the same.

A further purpose is to provide a perforated flange having locking ears on the baffles for support of the heat transfer tubes.

Further purposes appear in the specification and in the claims. In the drawings I have chosen to illustrate a lfewonlyo'f the numerous embodiments in which my invention may appear, choosing the forms shown from the standpoints of convenience in illustration, satisfactory operation and clear demonstratio'n of the principles involved.

Figure 1 isa verticalsection across a fuel'combustion furnace conforming to my invention.

Figure 2 'is a fragmentary perspective of the headers, heat transfer tubes and baffles, showing a minor variation in one baffle, I v

Figure -3 is a fragmentary perspective of the baffie flanges showing the perforations and looking ears before the heat "transfer tubes have been applied.

Figure 4 is a sectional perspective of the structure'of 'Fig'ure B'after 'the heat transfer tubes hate'been applied.

In the drawings like numerals refer to like parts.

Describing "in 'i'llustration'but not in limitationand referring to the drawings:

The -';present invention is concerned with fuel combustion furnaces of the type likely to be used as domestic heating furnaces, commonly known as hot water heaters or furnaces. The invention may be applied to the heating of other media, as for example to the generation and heating of steam.

The furnace of the invention has side walls 2| suitably consisting of an inner metallic housing 22, an outer metallic housing 23 and intermediate heat insulation 24, as well as a roof 25 similarly constructed. The furnace rests on a base 26. At the bottom is positioned a combustion chamber 21 which in some cases has a roof 28 and a water jacket 28 and is provided with a burner 29, intended to indicate any conventional type for introducing fuel and air, which might be oil, gas, pulverized coal, solid coal, or coke (using suitable fire bed supports not shown in the case of solid fuel). From the firebox a flue opening 36 extends upwardly into a heat transferflue 3| occupying the entire upper portion of the furnace, and terminating in a stack 32 at the top.

The heat transfer flue 3! is of serpentine contour due to the presence of bafiies 33 alternately extending from opposite side walls part only of the distance across to the wall opposite each cur-ved'at39 to aid in following the bend of heat transfer pipes to be described, and in Figure -1 the downward bend on one baflle is reversed at 39' to guide the gases. This is optional and is. omitted in Figure 2. i V

Suitably-positioned adjacent the top and bottom of the flue are a hot water header 40 for connection to thehot water heating system and :a cool water header 4! for connection to the cool water return from the heating system, or

to a cold water inlet. The water back 23', if

used, 'is suitably connected to the header 4! by "a pipe ll, and has inlet at H Connecting:

into each header and arranged side by side are serpentine bend heat transfer pipes 42, prefer :'a;b'ly "of copper, brass or bronze for good heat conductivity, .and having individual reverse bend portions 43 which conform to the bottoms of individual bafiles. It will be understood that the she'lfportions of the 'bafiies preferably upwardly slope at 44 from their origins to their outer edges, and that the reverse bend portions 43 of the pipes conform and preferably are substantially in contact with the under sides of the baffles along the shelf portions and along the downwardly bent portions 39. This aids in defleeting gases and in metallic conduction of heat from the bafiles to the heat transfer pipes in contact therewith.

In many prior constructions the gases at the reversals of serpentine bends have been carried far away from the heat transfer pipes, but this cannot be true in the present construction, since outer edge of successive bafiies.

3 the gases at each serpentine bend in the flue must flow between the pipes at 45 and then are compelled by the baflies to follow the curvature of the bends of the pipes by the next baflle above.

The bottom baflie 46 normally will not have this downwardly curved portion 39 and the top baiiie 4'1 will conveniently comprise only the downwardly bent portion, since the furnace roof will perform much of the function of the shelf portion.

One of the problems in the prior art has been the tendency of the heat transfer tubes to sag or deform because of inadequate support. At the outer ends of several baffles I provide suitably downwardly directed flanges 48 having perforations 49 in the paths of the heat transfer pipes and severed at the middle of each perforaasssms tion to the edge of the flange at 50 to provide retaining ears 5i.

To support the heat transfer pipes the retaining ears in pairs are bent respectively backward and forward between each two perforations as shown at 52 in Figure 3, using pliers or the like, after which the pipes 82 are inserted in the perforations and the ears bent back to their normal positions as shown at 53 in Figure l. The completed result is shown in Figure 4. This bending is possible as the baflles will be made of sheet steel, copper or the like. Thus the flanges serve to lock and support each heat transfer pipe at the v The attachment is extremely convenient as it merely involves bending the ears on the perforations back and forth.

In operation the device of the invention can conveniently be assembled by uniting the heat transfer pipes in the headers as by welding or spreading the ends of the pipes, then applying the baffles to the pipes by bending the ears on the bailie flanges, then assembling the pipes in suitable pipe channels 54 and 55 through the inner walls of the furnace, then uniting the baflles to the end walls and finally assembling the end. Compared to the assembly time usually required, a marked reduction in assembly time is accom plished by the present invention.

The furnace of the invention will function in an improved manner due to the close contact between the heat transfer tubes and the under surfaces of the walls of the baffles, with at the same time allowance of adequate lateral spacing between the pipes to permit flow of flue gas between the pipes at the ends of the baffles.

In view of my invention and disclosure variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain all or part of the benefits of my invention without copying the structure shown, and I, therefore, claim all such insofar as they fall within the reasonable spirit and scope of my claims.

Having thus described my invention what I 0 Number 4 claim as new and desire to secure by Letters Patent is:

1. In a fuel combustion furnace, at flue having flue walls, a plurality of baffles supported from the flue walls one above another, each bafile extending from one side of the flue part only of the distance to the opposite wall of the flue and each alternate bafile extending from the opposite wall to form a serpentine flue passage, headers at the top and bottom of the flue, serpentine heat transfer pipes extending side by side through the flue, connected at the top and bottom to the headers and individual bends of the pipes extending along the bottoms of individual baflles, and flanges on the baffles having openings through the flanges through which the pipes pass to interconnect the'pipes with the bafiies.

2. In afuel combustion furnace, a flue having flue walls, a plurality of baiiies supported from the flue walls and extendingfro-m one side of the flue part only of the distance to the opposite side, the alternate baffles extending from opposite sides, and individual bafies being downwardly curved across their lengths adjoining the side from which they extend, top and bottom headers, serpentine pipes extending through the flue between the bafiles, connected at their ends to the headers and following the curvature and shape of the under pcrtions of the bailies, the curvature of the pipes following the curvature of the bailles at the sides from whichthe bafiles extend and flanges on the baffles having interconnecting openings through which the pipes pass.

3. In a fuel combustion furnace, a flue having flue walls, a plurality of superimposed bafiies supported from the flue walls and extending alternately from opposite sides of the flue part only of the distance across the flue so as toproduce a serpentine path, each baflie having at its outer end a downwardly directed perforated flange having integral locking ears, and serpentine pipes extending through the flue below the individual baffles and through the perforations of the flanges, being locked therein by the ears to support the pipes from the baffles.

WILLIAM B. LEVIS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Gunckel June 8, 1915 Duffy Apr. 4, 1922 Kuhner et a1 Apr. 29, 1941 Beers July 22, 1941 FOREIGN PATENTS Country Date Switzerland Mar. 16, 1934 Number

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