US3736961A

US3736961A - Heat exchanger for furnace pipes and the like

Info

Publication number: US3736961A
Application number: US00197228A
Authority: US
Inventors: R Walsh
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-11-10
Filing date: 1971-11-10
Publication date: 1973-06-05
Anticipated expiration: 1990-06-05

Abstract

A heat exchanger device for use between a furnace or boiler and chimney comprising a housing pipe and heat transfer thin metal disks with vanes arranged spoke like. Each disk has an annulus in tight contact with the interior of the pipe and the vanes, being thin and confined between a center hub-like structure and the annulus, tend to warp to increase their angular deflection of the gasses as the temperature rises to effect pronounced scouring on the interior of the pipe to maximize heat transfer into the pipe and thereby to the atmosphere. The annuli of the axially spaced disks are rigidified by interconnecting rods.

Description

United States atet 1 1 1111 3,736,961

Walsh 1451 June 5, 1973 [54] HEAT EXCHANGER FOR FURNACE 2,185,484 1 1940 Welch et a1 ..165/154 x PIPES AND THE LIKE [76] Inventor: Robert D. Walsh, 11 s. 544 Oak- P Exam'fi1echarles, Myhre wood Avenue, Lemont, L 60439 Asszstant ExammerS.J. R1chter Attorney-John J. Kowalik [22] Filed: Nov. 10, 1971 [21] App1.No.: 197,228 ABSTRACT A heat exchanger device for use between a furnace or 52 us. C1 ..138/38, 110 97 D, 165/40, boiler and chimney comprising a housing P p and 165/179 heat transfer thin metal disks with vanes arranged [51] Int. Cl. ..FlSd 1/02, F28f 1/40 spoke like. E h i k has an annulus in tight contact [58] Field of Search ..138/38; 165/40, 154, with the interior of the p p and the vanes, being thin [56] References Cited UNITED STATES PATENTS 2,879,976 3/1959 Rose ..165/154 X 1,880,533 10/1932 Thomas ..165/154 2,268,386 12/1941 Fisher ...165/156 X 2,890,866 6/1959 Hansen ..165/154 X and confined between a center hub-like structure and the annulus, tend to warp to increase their angular deflection of the gasses as the temperature rises to effect pronounced scouring on the interior of the pipe to maximize heat transfer into the pipe and thereby to the atmosphere. The annuli of the axially spaced disks are rigiditied by interconnecting rods.

7 Claims, 9 Drawing Figures Patented June 5, 1973 3,736,61

2 Sheets-Sheet. 1

Inventor FIG 4 Robert D. Walsh Attorney Patented June 5, 1973 3,736,351

2 Sheets-Sheet 2 FIG] FIGS H69 HEAT EXCHANGER FOR FURNACE PIPES AND THE LIKE DISCUSSION OF THE PRIOR ART Insofar as is known by the inventor, heat exchangers of the type under consideration have either constricted the flow of gasses of combustion into the chimney or permitted excessive flow so that most of the heat is exhausted into the chimney. Furthermore, the more effective units are relatively expensive to make and incorporate complex controls to vary the air flow.

SUMMARY OF THE INVENTION The primary object of the invention is to provide a novel, effective heat exchanger which is relatively simple and inexpensive to make and which is easy to clean and service.

A further object is to provide a heat exchanger which incorporates disks with thin gas-flow controlling blades which are adapted to warp as the temperature rises to obtain a swirling effect in the chamber so as to dissipate the heat into the housing and thereby into the atmosphere.

The invention comprehends a structure in which the heat transfer disks are adapted to be added or removed as requirements dictate.

A further object is to provide a novel device of the class described in which the vaned disks are notched about their peripheries and receive flexible longitudinal positioning rods therethrough, the rods adapted to be skewed in the annular pipe in order to offset the disks and also to tighten the assembly by twisting the rods whereby they assume a helicoidal shape in the pipe and hold the parts in tight engagement with each other and in good heat transfer relation.

These and other objects and advantages inherent in and encompassed by the inventions will become more readily apparent in the specification and the drawings, wherein:

FIG. 1- is a perspective view showing the invention applied between a boiler or furnace and a chimney;

FIG. 2 is an axial sectional view of the heat exchanger;

FIG. 3 is a crossectional view on a reduced scale taken substantially on line 33 of FIG. 2;

FIG. 4 is a fragmentary perspective view of the heat exchanger assembly;

FIG. 5 is an enlarged cross-sectional view taken substantially on line 5-5 of FIG. 4;

FIG. 6 is a cross-section on line 6-6 of FIG. 4;

FIG. 7 is a cross-section of a further embodiment of the invention;

FIG. 8 is a sectional view on an enlarged scale taken substantially on line 8-8 of FIG. 7, and

FIG. 9 is an axial section taken on line 99 of FIG. 8.

DESCRIPTION OF FIGS. 1 6.

The heat exchanger generally designated 2 is fitted between the exhaust of the boiler or furnace 3 and the flue opening 4 of the chimney 5.

The exchanger comprises a preferably galvanized steel pipe 6 of hollow cylindrical form and reduced inlet and

outlet end portions

7 and 8. At least the outlet end portion has an annular tubular portion 9 fitted within the adjacent end 10 of the pipe 6 and the portion 9 is connected to pipe 6 by self-tapping screws 11. A

frusto-conical section 12 connects the ring 9 with the reduced pipe extension 13. Similarly the inlet end is formedwith a frusto-conical portion 14 and a reduced end pipe 15. Thus the heat exchanger is larger in diameter than the inlet or outlet. This provides an expansion chamber and the constricted outlet to trap and efficiently transfer the heat from the chamber 16 to the pipe wall 6 and thereby transfer by convection and otherwise the heat into the surrounding atmosphere.

The interior surface 19 of the pipe 6 is cylindrical and in intimate contact with the edges 20 of annular heat transfer elements 21 which not only serve to transfer heat to the pipe by conduction but also serve to swirl the heat entrained air within the transfer chamber.

Each element 21 is a thin disk of sheet metal such as galvanized steel although other metals may be used, and comprises a peripheral annulus or ring 23 which is a relatively narrow band connected by radially extending

vanes

24, 24 formed in the manner of spokes and connected to a central hub-like support 25. The vanes are connected by reversely bent end connectors 26, 27 (FIG. 6) to the support 25 and the annulus 23 and the vanes of each disk are offset circumferentially of the vanes of the adjacent disks so as to cause the gasses flowing from the inlet to the outlet to swirl within the chamber and thus bathe the vanes and the interior of the pipe with the hot gasses so as to extract maximum heat therefrom. As the temperature rises the vanes tend to expand and being confined tend to warp and twist so as to distort the angle of incidence of each blade with the path of gas flow, and thus create a deviate path through the chamber thus increasing the dwell of the gasses within the chamber. The distortion of the blades is accommodated by the offset construction of the

end connectors

26, 27 which are of thinner section than the blades and the center support and annulus since these portions must be stretched in the upsetting. They also are bendable transversely different amounts along the width of the blade since they are of generally triangular shape.

The outer edge 20 of each annulus is notched at 31, 31 and connector rods or

bars

32, 32 are fitted therein. These bars are thin in cross-section and are flexible and have their outer sides 33 slidably fitted against the interior surface of the housing. After the disk assembly is fitted into the chamber, the assembly may be twisted so that a tight fit develops since the bars tend to be twisted, it being understood that the notches 31 are dimensioned to accommodate such slight twisting. The twisting may be preceded by spraying the surface 19 with a light evaporative lubricant prior to insertion of the disk assembly.

EMBODIMENT OF FIGS. 7-9.

In the present embodiment parts identical with the previous embodiment are identified with the same reference numerals.

The housing 6 encases the heat-transfer finned radiator or diverter 50 which is similar to heat transfer element 21 of the previous embodiment, and comprises for simplicity of manufacture, a center rod 51 which has threaded

ends

52, 53 on which are threaded

nuts

54,54. A stack or

spacer spools

55,55 and intervening finned or

vaned metal disks

56,56 are sleeved on the shaft 51. Each disk 56 has an annular peripherical por: tion or outer ring 57 with its outer periphery 58 in intimate contact with the interior surface 19 of the center section 6. Each disk has angled, circumferentially spaced, radial blades or vanes 59 which extend between the inner and

outer rings

57,60 and are formed with these as sheet metal stampings in a single piece. The thinness of the vanes combined with the angularity of the blades and close confinement of the disks are conducive to the blades warping and thus producing a nonuniform labyrinthian passageway 65 between the blades and through the intervening spaces between the disks for the hot gasses passing from the inlet to the outlet, particularly when adjacent disks are arranged with their vanes offset from each other. It will be seen that each inner ring has a center aperture 69 receiving the rod therethrough and the disks are held tightly on the rod by the end nuts.

Several embodiments of the invention have been described, however other forms will now become readily apparent and would come within the scope of the appended claims.

I claim: 4

1. For use between a boiler and the like and a chimney, a heat exchanger for conducting hot combustion gasses therethrough comprising an elongated housing providing a chamber having an inlet and an outlet means and diverter means within the chamber for circulating such gasses within said chamber, said diverter means being formed of heat conducting material, self regulating means mounting said diverter means within said chamber for adjusting the positions thereof within said chamber, said diverter means comprising a plurality of disks with vanes thereon, and said means mount- 4 ing said disks within said chamber comprising flexible connecting bars adapted to be shifted within the chamber axially and circumferentially thereof for skewing said diverter means.

2. The invention according to claim 1 and said housing and diverter means being made of metal for conducting heat from within the chamber to the surrounding atmosphere and said diverter means comprising thin diskshaving radial vanes, a peripheral annulus, and a center support and means connecting the ends of the vanes to said annulus and support and having a modulus of expansion and contraction different than said vanes.

3. The invention according to claim 2 and said connecting means comprising integral flanges on the ends of said vanes and of thinner section than the vanes.

4. The invention according to claim 3 and said flanges tapering midwise of said vanes.

5. The invention according to claim 4 and said skewing means comprising flexible bars interposed between the interior of the housing and the disks and adjustably interlocked with the latter and displaceable axially within the chamber.

6. The invention according to claim 1 and said vanes having flanges connecting them with the adjacent portions of the disks and theflanges being of different section than the vanes.

7. The invention according to claim 6 and said housing having reduced inlet and outlet ends and said disks having intimate peripheral contact with the housing.

Claims

1. For use between a boiler and the like and a chimney, a heat exchanger for conducting hot combustion gasses therethrough comprising an elongated housing providing a chamber having an inlet and an outlet means and diverter means within the chamber for circulating such gasses within said chamber, said diverter means being formed of heat conducting material, self regulating means mounting said diverter means within said chamber for adjusting the positions thereof within said chamber, said diverter means comprising a plurality of disks with vanes thereon, and said means mounting said disks within said chamber comprising flexible connecting bars adapted to be shifted within the chamber axially and circumferentially thereof for skewing said diverter means.

2. The invention according to claim 1 and said housing and diverter means being made of metal for conducting heat from within the chamber to the surrounding atmosphere and said diverter means comprising thin disks having radial vanes, a peripheral annulus, and a center support and means connecting the ends of the vanes to said annulus and support and having a modulus of expansion and contraction different than said vanes.

6. The invention according to claim 1 and said vanes having flanges connecting them with the adjacent portions of the disks and the flanges being of different section than the vanes.