US 1991449 A
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F b. 19, 1935. F. H. CQRNELIUS v FURNACE Filed March 7, 1951 NEY 1/ I I I!!! fill/Ill I!!! Ill/l INVENTOR. Fran/K HCame/Ms.
ATTOR Patented Feb. 1935 UNITED STATES PATENT OFFICE 6 Claims.
My invention relates to furnaces and particularly to furnaces of the air circulating type.
One object of my invention is to provide a furnace of the above-mentioned type with a double jacket between which air is circulated under a positive pressure, in order to cool the outer'portion of the jacket.
Heretofore, in order to provide a cool outer jacket for furnaces and to prevent the radiation of heat therefrom, heat insulating materials were provided adjacent to the inner surface of the outer' wall that prevented the conduction of heat therethrough. These materials are costly and become deteriorated through use.
In practicing my invention, I provide an inner casing adjacent to the outer casing but separated therefrom to form a passage through which a small portion of the air that passes through the furnace is circulated. The air is passed through the furnace by an agitating device and a portion is forced, under pressure, between the two casings, in order to prevent the walls of the outer casing from becoming heated.
Another object of my invention is to provide a double casing for a furnace of the above-mentioned type with an ejector device that shall be operated by the passage of the heated air from the furnace to effect an increase in the flow of air between the casings, in order to prevent the walls of the outer casing from becoming heated and to permit re-heatingof the air after it has thus passed between the walls.
A further object of my invention is to provide a furnace of the above-mentioned type with a combustion chamber that shall be elevated above the floor of the furnace to permit a portion of the circulating air to pass thereunder and to flow into the passage provided adjacent to the outer walls.
With these principles and objects in mind, my invention will best be understood by referring to the following specification taken in conjunction with the accompanying drawing, wherein:
Figure 1 is a longitudinal sectional View of a furnace embodying my invention, and
Fig. 2 is a transverse sectional view of the structure illustrated in Fig. 1 taken along the line IIII thereof.
My invention comprises, in general, a combustion chamber 1 having associated radiating tubes 2 that are connected to a chamber or header 3 which is associated with a smoke breeching 4 that is connected to a chimney or flue in a known manner.
An air circulating system is associated with the passes.
outer surfaces of the tubes 2 and comprises an intake duct 5 through which air is drawn by a fan or blower 6, the air passing through an air filter '7 which is provided in an air passage 8 ahead of the fan 6, as shown in Fig. 1. The. air from the fan 6 is blown against the combustion chamber 1, the majority of which thereafter passes upwardly, as shown by the arrows, between the radiating tubes 2 where it becomes heated and. is forced out through the delivering duct 9. It is to be understood that the structure above described may be of any type, well known in the art to be suitable, as the particular construction thereof constitutes no part of the present invention.
The combustion chamber 1 and the radiating tubes 2 are enclosed by the end walls 10 and 11, the side walls 12 and 13 and the top and bottom plates 14 and 15, respectively, forming an outer casing or jacket 16. Adjacent to each of these surfaces and between the surfaces and the chamber 1 and the radiating tubes 2, is a second casing or jacket 17 that provides a space 18 between the outer casing 16 and the inner casing 1'7. The portion of the combustion chamber 1 adjacent to the fan 6 is provided with a; curved deflector 19 and-a companion deflector 21 that divide and direct the air contacting therewith. As air is forced against the surfaces 19 and 21, a greater the positive pressure supplied thereto by the fan or blower 6.
To prevent too great a load on the fan 6 when effecting an adequate flow of air between the casings 16 and 17, a reduced pressure area is provided at the delivering duct 9 that causes an in-. creased flow of the air in the passage 18. A short duct 20 is provided on the inner casing 17 through which the main body of heated air The duct 20 is positioned within the delivering duct 9 and the flow of air into the duct 9 from the duct 20 produces an area of reduced pressure'in the upper portion of the passage 18 in the manner of an ejector. The air in the passage 18, that is being moved by the pressure of the fan 6, is accelerated by the presence of the reduced pressure area at the outlet thereof. Y
The combined action of the reduced pressure area at the upper end of the space 18 and the positive pressure provided at the bottom thereof by the blower 6, effects a rapid flow of the air between the casings 16 and 17 that is sufficient to prevent the heating of the outer casing 16. This flow of air. in the passage 18 is produced without an appreciable increase of resistance to the flow of the entire body of air that is circulated by the fan or blower 6.
Referring to Fig. 2, it will be noted that the casing or jacket 17 is suitably spaced apart from the outer casing or jacket 16 and the combustion chamber 1 and the radiating tubes 2, in order that air may flow between the inner casing 17 and the chamber 1 and radiating tubes 2. This construction assures the complete cooling of the outer casing 16, since the partition 1'7 will be consider ably cooled by the passage of air across its inner surfaces.
The air deflectors 19 and 21 are hinged together by the pin 22 and hinged to the inner casing 1''! by the pin 23. The upper end of the defiector 19 is attached to an adjustable device 24 that raises or lowers the deflector 19Qthereby changing the position of the deflectors within the main air passage and regulating the amount of air deflected into the passage 18. The device 24 may be of any type, well known in the art to be suitable; and is herein illustrated as constituting a screw 25 pivotally supported on the chamber 1 and a nut 26 attached to the deflector 19. Apertures'27 may be provided in the deflectors 19 and 21 for the passage of a small amount of air therethrough for cooling the adjacent wall of the chamber 1.
It will thus be seen that I have provided a furnace with a passage between two enclosing casings through which air is circulated, in order to prevent the heat produced within the furnace from being conducted to the outer casing.
The rapid flow of air through the passage is effected by a suction produced in the upper portion of the passage in conjunction with a positive pressure provided by a fan or blower at the bottom of the passage. 1
While I have described and illustrated a single embodiment of my invention, it is to be understood by those skilled in the art that many changes, additions, omissions and substitutions may be made therein withoutdeparting from the spirit and scope of my invention, asset forth in the accompanying claims.
I claim as my invention:
1. The combination with a furnace including a blower for a medium to be heated and circulated, of an inner and an outer jacket enclosing the bottom and four other sides of the furnace and in closely spaced relation to each other, a vertical conduit connected to the outer jacket for the delivery of the medium, and a short vertical conduit on the inner jacket extending within the first said conduit in such manner as to impart a movement to the said medium between the said jackets when said blower is operating.
2. The combination with a furnace including a blower for a medium to be heated and circulated, of an inner and an outer jacket enclosing the bottom and four other sides of the furnace and in closely spaced relation to each other, and closely spaced concentric vertical conduits for connecting the outer and inner jackets at the point of deliv ery of the inner jacket remote from said blower thereby to produce an area of reduced pressure by ejector action within the outer jacket to provide a movement of the portion of the medium therein when the main portion thereof is propelled through the inner jacket by means of said blower.
3. In combination with a furnace including a blower for a medium to be heated and circulated. of inner and outer enclosing jackets for the furnace in closely spaced relation to each other, the inner jacket having inlet means entering into the enclosed space between said jackets adjacent to the propelling means for permitting a positive pressure from said blower in a portion of said medium passing therein, the blower also producing positive pressure within said inner jacket, and outlet means associated with said space that effects the joinder of said portion with the medium after said portion has passed through said space.
4. The combination with a furnace adapted to heat a medium and a blower for circulating said medium, of an inner and an outer jacket for the furnace'in spaced relation to each other, means disposed near the delivery end of said blower for deflecting a portion of the said medium into the space between the said jackets, and adjustable means on said deflecting means for regulating the amount of said medium passed into said space to vary the temperature of said outer jacket.
5. The combination in a furnace for heating and circulating a medium, of a heat exchanger, a fan for blowing the circulated medium towards said heat exchanger, an enclosed passage between the said exchanged and the outer surface of the furnace and a deflecting device located in front of said fan for dividing the medium and directing it into the heat exchanger and said passage.
6. The combination in a furnace including a combustion chamber and associated radiating surfaces, of an air-circulating device disposed to blow air upon said surfaces and located near the bottom of the furnace, a casing enclosing the said chamber, surfaces and device, a partition separating said chamber and surfaces from said device and through which the delivery end of said device extends, a second casing enclosing said chamber and surfaces on all sides except that occupied by said partition and except for an opening in the bottom side near said delivery end of said device and an outlet in the top side, whereby a portion of the air circulated by said device flows between said two casings.
FRANK H. CORNELIUS.