US2749904A

US2749904A - Forced air flow air heating furnace

Info

Publication number: US2749904A
Application number: US272096A
Authority: US
Inventors: Don F Jones; Kenneth S Bassett
Original assignee: Motor Wheel Corp
Current assignee: Motor Wheel Corp
Priority date: 1952-02-18
Filing date: 1952-02-18
Publication date: 1956-06-12
Anticipated expiration: 1973-06-12

Description

June 12, 1956 D. F. JONES ET AL 2,749,904

FORCED AIR FLOW AIR HEATING FURNACE Filed Feb. 18, 1952 4 Sheets-Sheet 1 FIG. INVENTORS Dom Ff JONES 3; BY KENNETH S. BAssErr A TTOENE Y5.

June 12, 1956 D. F. JONES ET AL 2,749,904

FORCED AIR mow AIR HEATING FURNACE Filed Feb. 18, 1952 4 Sheets-Sheet 2 INVENTORS Do/v F do/vEs 6i KENNETH S. BASSETT June .12, 1956 D. F. JONES ET AL 2,749,904

FORCED AIR FLOW AIR HEATING FURNACE Filed Feb. 18, 1952 4 Sheets-Sheet s mmvrozas DoN F JONES 34 KENNETH 5. BAssETT ATTORNEYJ.

June 12, 1956 D. F. JONES ET AL FORCED AIR FLOW AIR HEATING FURNACE Filed Feb. 18, 1952 4 Sheets-Sheet 4 56 C 47 as INVENTORS DoN F JONES &

KENNETH 3. BAssETT ATTORNEYS.

United States Patent FORCED AIR FLOW AIR HEATING FURNACE Don F. Jones and Kenneth S. Bassett, Lansing, Mich, as-

signors to Motor Wheel Corporation, Lansing, PVEZCIL, a corporation of Michigan Application February 18, 1952, Serial No. 272,636

16 Claims. (Cl. 126110) This invention relates to a heater construction and more particularly to a space heater designed primarily for relatively small enclosures such as house trailers.

It is an object of this invention to provide a heater or compact construction, a heater having one or more insulated side walls so that it can be positioned directly adjacent a wall or in a corner to thereby reduce to a minimum provided with a cabinet having one or more ofits walls insulated by a shield spaced from the wall and defining an air chamber between the wall and'the shield. This air chamber not only insulates the wallof the cabinet but also provides an airduct through which outside air may be admitted into the air-circulating system of the heater. The heater cabinet is'furthermore provided with an upright partition which divides the cabinet into two chambers relativelyinsulatecl one from't-he other. In one chamber there is positioned the burner and-combustion chamber of the heating unit; and in the other chamber the controls, the blower mechanism, and the fuel tank,

in the casing of a heater which includes :a fuel tank, are

enclosed.

In the drawings: Fig. 1 is a perspective view of the heater. Fig. 2 is a perspective view on an 'enlarged scale of' the heater, portions being broken away to better show the construction within the cabinet.

Fig. 3 is a front sectional view of the h'e'ater'taken substantially along the lines 33 in Fig. 4.

Fig. 4 is a fragmentary sectional view of the heater with the oil tank and other parts thereof removed.

Fig. 5 is a fragmentary sectional 'view taken substantially along the lines 5-5 in Fig. 4.

Fig. 6 is a sectional view showing the base of the heater taken substantially along the lines 6-6in Fig. 4.

The heater shown includes a cabinet 10 supported upon a base 11. Cabinet 10 includes

side walls

12 and 13, a rear wall 14, and a front wall 15 formed with an opening '16 normally closed by a door 17 hinged on the front wall as at 18 to swing on a vertical axis. The top of the cabinet 10 is closed by an imperforate top wall 19. Base '11 is formed as an open bottomed, rectangular frame having

side walls

21 and 22, front and back walls '23 and 24,

respectively, and a top wall 25 which closes and forms a bottom wall for the lower end of cabinet 10. 'It will be observed that the walls of base 11 define an air chamber 26 which is closed at its bottom face by the'fioor 27 on which the heater is supported.

upon the top wall 25 of base 11.

2,749,904 Patented June 12, 1956 ice Within cabinet 10 there is arranged an upright partition 28 which divides the interior of the heater cabinet into two sections or

chambers

29 and 30. Within chamber 29 there is supported on the top wall 25 of base 11 a burner and combustion chamber casing 31. Top wall 25 of base 11 has an opening 32 disposed centrally of casing 31 for admitting outside air in chamber 26 to the burner (not shown) within casing 31. The outside air is preferably admitted to chamber 26 through an opening 33 in floor 27 in which a metal floor flange 34 is arranged. It may be stated at this point that, although an oil heater is shown, it will be appreciated as the description proceeds that the invention is equally applicable to a heater which utilizes gas as fuel.

The side wall of the heater adjacent the section 30, that is, the side wall 12, has a louvered opening 36 at the upper end thereof and a second louvered opening 37 adjacent the lower end of the cabinet. Likewise, at the front of the cabinet there is provided a louvered opening 38 near the top of the cabinet and another louvered opening 39 at the lower portion of door 17. Within the cabinet there are arranged three wall shields 4t), 41 and 42. Shield 40 is spaced inwardly of side wall 13. Shield 41 is spaced inwardly of rear wall 14, and shield 42 is spaced downwardly of top wall 19. Shield 42 is positioned on the upper edges of

shields

40 and 41. The lower edges of

shields

40 and 41 are flanged as at 43 and supported It will be observed that partition 28 terminates at its upper end below shield 42 so that chambers 2? and 30 communicate at their upper ends.

The

wall shields

40 and 41 cooperate with walls 13 and .14, respectively, to form an air duct 45 which extends upwardly within the heater cabinet from the base 11 around side wall 13 and rear wall 14. At one vertical edge the duct 45 is closed by a flange 46, and at its other vertical edge the duct 45 is closed by the end wall piece 47 which extends between shield 41 and wall 14 (see Fig. '6). At its lower end the wall duct 45 communicates with thechamber 26 and base 11 through the openings 48 in wall 25. At its upper end the air duct 45 opens into the space 49 between top shield 42 and top wall 19.

-minates along a line spaced below shield 42 so that

chambers

29 and 30 communicate at their upper ends. Within chamber 29there is arranged a blower '52 within a housing 53. The inlet 54 of housing 53 communicates with a blowerbox '55 which is mounted on shield 41 and partition 28. Blower 52 is driven by a motor 56 which is in turn partially enclosed by a shroud '57. An annular clearance space 58 enables air to be drawn into blower -52 between shroud 57 and motor 56 to prevent the motor frombecoming excessively heated.

The wall duct 45 communicates with the interior of the blower box 55 through an opening 60 in shield 41. This opening is controlled by a damper 61 pivotaily supported as at 62 and provided with an operating arm 63. Damper 61 can be positioned to vary the size of opening 60 and thereby control the quantity of air drawn into the blower from duct 45. The interior of blower box '55 also com- Imunicates with the heat chamber 29 through an opening 64 in partition 2.

It will be observed that opening 64 is disposed adjacent shield 41 and that casing 31 is spaced forwardly of shield 41. Thus, the opening 64-is arranged more or less tangential to the heat section 29 so that-direct radiation from casing 31 does not strike the blower, and the blower and motor are thereby prevented from becoming overheated from such radiation.

The blower housing 53 has a downwardly opening outlet 65 to which is connected a warm air duct 66. Duct 66 extends downwardly through chamber 39 from outlet 65 to the inlet 67 of plenum chamber 68 which is supported in the cold-air chamber 26 with its inlet 67 projecting upwardly through top wall 25 of base 11. Warm air duct 66 is provided with a damper 59 and is surrounded by a shield 69 which extends around theduct from the rear shield 41 to a shield 70 on the partition 28. Plenum chamber 68 is formed with a plurality of outlets 72 one of which opens through front wall 23 of base 11, another through side wall 21 of base 11, and another through rear wall 24 of base 11. The outlets 72 in

walls

23 and 21 are provided with louvers 73, and the outlet in the rear wall 24 is closed by a cap 74 which may be removed if it is desired to extend a heat duct from the plenum chamber to a more remote point in the enclosure heated. The bottom wall of plenum chamber 68 is provided with a knock-out disc 75 which may be removed if it is desired to extend a heat duct from the plenum chamber below the supporting floor 27 to another room in the structure being heated. Plenum chamber 68, it will be observed, is supported by the side walls of base 11 in spaced relation to wall 25 and floor 27. Thus, the plenum chamber is substantially completely surrounded by the cold air in chamber 26.

Within chamber 30 of the cabinet there is also arranged a fuel tank 76 which supplies fuel to the burner within casing 31 through a fuel-control valve 77. Valve 77 is supported on wall 25 within chamber 30 and connects with the burner in casing 31 by means of a fuel line 71. A control rod 7 8 extends from valve 77 upwardly through top wall 19 and is provided with a knob 79 for controlling the rate at which fuel is admitted to the burner. Below fuel valve 77, wall 25 of base 11 is formed with a trough 80 which extends from a point below fuel valve 77 to the opening 32 below casing 31. This drip channel or trough conducts any fuel which might drip from valve 77 to the opening 32 from which it is discharged through the opening 33 in the floor 27 on which the heater is supported. The service cord 81 extends through aligned openings 71 in rear wall 14 and rear shield 41 and is connected to motor 56 through a manual switch 82 mounted on shroud 57 and a thermo switch 83 which is mounted on partition 28 and shield 70. Thermo switch 83 is responsive to the temperatures within heat chamber 29 to operate the blower. If desired, manual switch 82 may be in the form of a three-way switch to enable the switch to also connect and disconnect the entire electrical circuit of the heater with the power line with which service cord 81 connects. For convenience, there is supported on shield 70 a shut-off stem 84 which can be manipulated within tank 76 for shutting off the flow of fuel to fuel valve 77. Stem 84 has a hooked portion 85 at one end which, when the stem is inserted through the louvered opening 36 on wall 12, may be engaged with control arm 63 to regulate the position of damper 61.

The top wall 25 of base 11 is provided with an opening 87 for accommodating a fuel line in cases where an outside fuel tank is used in place of tank 76. Under such circumstances, the fuel line would extend upwardly through the floor 27 and base 11 through opening 87 and connect with valve 77. A corner partition 88 (Fig. 6) divides the chamber through which the outside fuel line passes from the cold air chamber 26 of base 11.

Air for combustion is supplied to the burner from chamber 26 into which cold outside air flows through the floor flange 34. The cold air in chamber 26 also flows through openings 48 upwardly through duct 45 where it is warmed slightly and travels across the space 49 between top shield 42 and top wall 19 and out of the cabinet through the top louvers of

openings

36 and 38. This continual flow of air through the duct 45 and the space 49 will maintain

walls

13 and 14 relatively cool. Thus, the heater may be positioned directly against a wall or in a corner of the trailer or other enclosure being heated without subjecting the wall or corner of the trailer to excessive heating.

The arrangement of the louvered openings on the front and side walls of the heater cabinet produces a natural circulation of air upwardly through each of the

chambers

29 and 30. The air flowing into chamber 29 through the lower opening 39 is heated by casing 31 and flows out of the cabinet through upper opening 38. Air flows into chamber 30 through opening 39 on the door 17 of the cabinet and through opening 37 on the side wall 12 of the cabinet, and this air flows out of the cabinet through the

openings

38 and 36. There will be substantially no cross flow of heated air from chamber 29 into chamber 30, at least into that portion of chamber 38 below the upper edge of partition 28. Thus, the temperature of the fuel tank 76, valve 77, and motor 56 is maintained at an allowable maximum by the shielding around chamber 30, as well as by the continual circulation of air through this chamber. It will be observed that shield 70 is spaced from partition 28 and thus provides an air duct between

chambers

29 and 30. The shield 70 therefore protects the units in chamber 30 from the heat radiated from casing 31. Likewise, the shield 69 forms an air duct around the heat duct 66, thus directing the heated air around duct 66 upwardly in chamber 30 and away from tank 76, valve 77, and motor 56.

In mild weather the natural circulation of air upwardly through the cabinet of the heater may be sufficient to maintain the enclosure at the desired temperature. If this natural gravity circulation is not sufficient, then blower 52 may be utilized to provide a forced air circulation. When the motor 56 is in operation, hot air is drawn into the blower box 55 from heat chamber 29 through opening 64 in partition 28. This heated air is directed by blower 52 downwardly through duct 66 and into the plenum chamber 68. From the plenum chamber the heated air is directed outwardly across the floor through the louvered openings 73. The provision of the plenum chamber 68 in the base of the heater is therefore desirable not only because it adapts the heater for a more compact construction but also because it enables discharging the heated air from the bottom of the heater and outwardly over the floor of the structure being heated.

It will be observed that the cold outside air never comes into contact with the heated casing 31. When blower 52 is not operating, the outside air flows upwardly through duct 45 and outwardly of the cabinet through the louvers of

openings

36 and 38 above shield 42. When blower 52 is operating, the outside air flows into the blower where it is mixed with the room air which flows up and around and is heated by casing 31.

Experience has shown that in small enclosures such as trailers the humidity often tends to rise to an excessive value. With the heater of this invention the humidity within the enclosure being heated can be maintained at a comfortable value by simply controlling the amount of outside air admitted into the circulating air system of the heater, that is, by controlling the position of damper 61 so as to increase or decrease the size of opening 60. The cool air flowing into the blower box 55 through opening 60, which normally contains less moisture than the warmer air within the enclosure being heated, mixes with the hot air flowing into the blower box through opening 64 and is discharged through the louvered openings 73.

In warm weather blower 52 can be utilized for bringing fresh air into the enclosure, thus enabling use of the arrangement as a cooling means.

We claim:

1. In a heater construction, the combination of a cabinet having side walls, a heating unit in said cabinet,

means cooperating with at least one of said side walls to form an air duct which is substantially coextensive with said side wall and which insulates said one side wall from the heat within said cabinet, and a blower on said cabinet having an inlet connected with said air duct adjacent its upper end, said air duct having an inlet adjacent its lower end adapted to connect with a source of outside air, said cabinet having a chamber therein in which said heating unit is located, said chamber having an opening adjacent the lower end thereof communicating with the space immediately surrounding said cabinet, said blower inlet also being connected with said chamber, said blower having an outlet communicating with the exterior of said cabinet, said blower being arranged to draw air from said chamber and duct and discharge said air exteriorly of said cabinet, and means adjacent the blower inlet for varying the proportions of air passing into said blower from said air duct and said chamber.

2. In a heater construction, the combination of a cabinet having side walls, a heating unit in said cabinet, a shield within said cabinet spaced inwardly of at least one of said side walls and cooperating therewith to form a duct therebetween which insulates said wall from the heat within said cabinet, a blower in said cabinet, said shield having an opening therein, said blower having an inlet connected with said opening, said duct having a second opening therein for admitting outside air to said duct, said cabinet having a heat chamber in which said heating unit is located, said blower inlet also communicating with said heat chamber, said blower having an outlet communicating with the exterior of said cabinet, said blower being arranged to draw air from said duct and chamber through said inlet and discharge said air exteriorly of said cabinet, and means adjacent said blower inlet for regulating the proportions of air drawn into said blower from said heat chamber and said duct.

3. The combination set forth in claim 2 wherein said air duct is substantially coextensive with said side wall.

4. In a heater construction, the combination of a cabinet having side walls, a heating unit in said cabinet, a shield within said cabinet spaced inwardly of at least one of said side walls and cooperating therewith to form a duct therebetween which insulates said wall from the heat within said cabinet, a blower in said cabinet, said shield having an opening adjacent its upper end, said blower having an inlet connected with said opening, a horizontally disposed partition adjacent the lower end of the cabinet and defining at the base of the cabinet an air chamber communicating with the lower end of said duct, said air chamber having an opening therein adapted to be connected with a source of outside air, means defining a plenum chamber within said air chamber, duct means extending downwardly from the outlet of said blower to said plenum chamber, and means defining an outlet from said plenum chamber to the exterior of the cabinet.

5. In a heater construction, the combination of a cabinet having side walls, a heating unit in said cabinet, a generally vertically extending air duct adjacent and substantially coextensive with one of the side walls of said cabinet, said air duct insulating said one side wall from the heat within said cabinet, a blower on said cabinet having an inlet connected with said air duct adjacent its upper end, means adjacent the lower end of the cabinet defining an air chamber communicating with the lower end of said duct and having an opening therein adapted to be connected with a source of outside air, means defining a plenum chamber within said air chamber, the walls of said plenum chamber being generally spaced from the walls of said air chamber so that the plenum chamber is substantially completely surrounded by the outside air in said air chamber, duct means extending from the outlet of said blower to said plenum chamber, and means defining an outlet from said plenum chamber to the exterior of the cabinet.

6. In a heater construction, the combination of a -cabinet having side walls, a heating unit in said cabinet, '2). generally vertically extending air duct adjacent and substantially coextensive with one of the side walls of said cabinet, said air duct insulating said one side wall from the heat within said cabinet, a blower on said cabinet having an inlet connected with said air duct adjacent its upper end, a horizontally disposed partition adjacent the lower end of the cabinet and defining at the base of the cabinet an air chamber communicating with the lower end of said duct, said air chamber having an opening therein adapted to be connected with a source of outside air, means defining a plenum chamber within said air chamber, the walls of said plenum chamber being generally spaced from said partition and the walls of the cabinet at the base thereof so that the plenum chamber is substantially completely surrounded by the outside air in said air chamber, duct means extending from the outlet of said blower to said plenum chamber, and means defining an outlet from said plenum chamber to the exterior of the cabinet.

'7. In a heater construction, the combination of a cabinet having a top wall and side walls, an upright partition in said cabinet dividing-the interior of the cabinet into two adjacently positioned chambers, insulating shields spaced inwardly of two side walls of the cabinet defining one of said chambers and cooperating with said two side walls to form an air duct, an insulating shield spaced downwardly of the top wall of said cabinet and defining a top wall for said chambers, said air duct communicating at its upper end with the space between said top shield and the top wall of the cabinet, a horizontally disposed partition adjacent the lower end of the cabinet, said last mentioned partition forming a bottom wall for said chambers and defining an air chamber therebelow, said air chamber being adapted for connection with a source of outside air and communicating with said air duct, and a heating unit in said one chamber, said chambers each having openings adjacent the upper and lower ends thereof to permit air surrounding the cabinet to circulate upwardly through said chambers, said cabinet having openings above said top wall shield providing an outlet for said air duct.

8. The combination set forth in claim 7 including a blower in said other chamber, said blower having an inlet communicating with said first mentioned chamber.

9. In a heater construction, the combination of a cabinet having a top wall and side walls, an upright partition in said cabinet dividing the interior of the cabinet into two adjacently positioned chambers, insulating shields spaced inwardly of two side Walls of the cabinet defining one of said chambers and cooperating with said two side walls to form an air duct, an insulating shield spaced downwardly of the top wall of said cabinet and defining a top wall for said chambers, said air duct communicating at its upper end with the space between said top shield and the top wall of the cabinet, a horizontally disposed partition adjacent the lower end of the cabinet, said last mentioned partition forming a bottom wall for said chambers and defining an air chamber therebelow, said air chamber being adapted for connection with a source of outside air and communicating with said air duct, a heating unit in said one chamber, said chambers each having openings adjacent the upper and lower ends thereof to permit air to circulate upwardly through said chambers, said cabinet having openings above said top wall shield providing an outlet for said air duct, a blower in said other chamber, said blower having an inlet communicating with said first mentioned chamber, and a plenum chamber in said air chamber below said horizontal partition, duct means extending from the outlet of said blower to said plenum chamber, and means defining an outlet from said plenum chamber to the exterior of the cabinet.

10. The combination set forth in claim 9 wherein the inlet of said blow er also communicates with said air duct adjacent the upper end of the chamber in which said blower is disposed.

11. The combination set forth in claim 10 including means for controlling the quantity of air admitted from said air duct to the inlet of said blower.

12. In a heater construction, the combination of a cabinet having side walls, means cooperating with at least one of said side walls to form an air duct extending vertically in said cabinet which insulates said side Wall from the heat within said cabinet, means defining at the base of the cabinet an air chamber having an opening therein adapted to be connected with a source of outside air, said air duct communicating at its lower end with said air chamber, means defining a heat chamber in said cabinet, a heating unit in said heat chamber, said heat chamber having an inlet opening therein communicating with the space immediately surrounding said cabinet, a blower in said cabinet having an inlet connected with said heat chamber and said air duct, said blower having an outlet communicating with the exterior of said cabinet, said blower being adapted to draw air from said heat chamber and air duct through said blower inlet and discharge said air exteriorly of said cabinet, and means adjacent said blower inlet for regulating the relative proportions of air drawn into said blower from said heat chamber and said air duct.

13. The combination set forth in claim 12 wherein said first mentioned means comprises a shield spaced adjacent said side wall of said cabinet, said shield having an opening therein communicating with the inlet of said blower, said last mentioned means comprising means for varying the effective size of said opening in said shield.

14. In a heater construction, the combination of a cabinet, a heating unit in said cabinet, a generally vertically extending air duct in said cabinet, a blower in said cabinet having an inlet connected with said air duct adjacent its upper end, wall means defining at the base of said cabinet a generally enclosed air chamber communicating with the lower end of said air duct, said air chamher having an opening therein communicating with the exterior of the cabinet for the admission of air to said air duct and said blower, means defining a plenum chamber within said air chamber, duct means extending downwardly from the outlet of said blower to said plenum chamber, and means defining an outlet from said plenum chamber to the exterior of the cabinet.

15. The combination set forth in claim 14 wherein said cabinet includes a heating chamber in which said heating unit is located, said inlet of said blower also communicating with said heating chamber.

16. The combination set forth in claim 15 wherein said heating chamber is provided with an inlet opening communicating with the exterior of said cabinet.

References Cited in the file of this patent UNITED STATES PATENTS 1,074,194 Pascoe Sept. 30, 1913 1,089,728 Smith Mar. 10, 1914 1,169,448 Williams Jan. 25, 1916 1,673,072 Houghtby June 12, 1918 2,241,025 Wedderspoon May 6, 1941 2,279,974 Evans Apr. 14, 1942 2,279,975 Evans Apr. 14, 1942 2,356,705 Siegler Aug. 22, 1944 2,457,818 Heiman Jan. 4, 1949 2,526,016 Figg Oct. 17, 1950