US2642859A

US2642859A - Fireplace heating system

Info

Publication number: US2642859A
Application number: US94398A
Authority: US
Inventors: Newman T Brown
Original assignee: FRANK A MORTIMER
Current assignee: FRANK A MORTIMER
Priority date: 1949-05-20
Filing date: 1949-05-20
Publication date: 1953-06-23
Anticipated expiration: 1970-06-23

Description

r o t n e Z n n 3 4 Sheets-Sheet 1 NEW/*7 I Gflomeg June 23, 1953 N T BROWN FIREPLACE HEATING SYSTEM Flled May 20 1949 June 23, 1953 N. 1'. BROWN 2,642,359

' FIREPLACE HEATING SYSTEM Filed May 20, 1949 4 Sheets-sheaf. 2-

3noentor NEW/WIN 7'. Bzaow/v Ottomeg June 23, 1953 N. T. BROWN FIREPLACE HEATING SYSTEM 4 Sheets-Shebt 5 Filed May 20, 1949 Patented June 23, 1953 FIREPLACE HEATING SYSTEM Newman T. Brown, Edmonds, Wash, assignor to Frank A. Mortimer, Seattle, Wash.

Application May 20, 1949, Serial N 0. 94,398

1 This invention relates to fireplace heating systems and has reference more particularly to a fireplace heating system of an improved form; a device that may readily be disposed within the combustion chamber of a domestic fireplace of the usual type of construction, or within acirculating, air-heating fireplace, to convert the fireplace into a circulating heater.

It is'the principal object of this invention to provide a fireplace heater of the above stated character, built as an integral unit and made ready for instant use merely by properly disposing it in the fireplace combustion chamber of any make of fireplace or fireplace heating unit; that requires no change or alteration in the fireplace structure for its application thereto and which may be easily withdrawn from use should it be desired to use the fireplace or circulating airheating fireplace in the usual way. Furthermore, to provide a circulating air heater for use within a fireplace, that takes advantage, to the maximum extent, of heat that is contained in the smoke and gases of combustion and which usually is wasted through the fireplace chimney.

It is also an object of the invention to provide a heater of the above stated character, having a firebox provided with a damper-equipped top fiue or outlet, permitting direct outflow of smoke and gases of combustion to the fireplace chimney and provided immediately about the said firebox with an enclosing housing providing anair heating chamber having air intake and discharge openings in direct communication with the area or room to be heated; the said smoke and gas outlet of the firebox being equipped with lateral outlets through which, upon closing the damper, the smoke and hot gases will be diverted and caused to flow downwardly and around the said air chamber to dissipate its heat thereto, thus providing means for causing smoke and gases of I combustion to fiow over all sides of the air chamber both inside and out.

It is also an object of the present invention to provide a novel arrangement of baflies in association with the passages provided for the flow of smoke and hot gases, whereby the latter will be caused to be distributed over the maximum area of those surfaces with-which the air that is to be heated comes in contact.

Still further objects of the invention reside in the various details of construction of parts embodied in the device and in their relationship and mode of use as will hereinafter be fully described.

In accomplishing these andother objects of the invention, I have provided the improved de-- 2 Claims. (01.126-121) tails of construction, the preferredlforms of which are illustrated wherein:

Fig. 1 is a front view of a typical fireplace, equipped with a circulating air heater embodying the improvements of the present invention therein.

Fig. 2 is a somewhat enlarged vertical section in the accompanying drawings,

, of the fireplace and heater. as disposed therein;

the view being taken on the line 2-2 in Fig. 1. Fig. 3 is a perspective view of the present heater, removed from the fireplace and showing portions of walls of the various housings broken away for better illustration and understanding of enclosed parts.

Fig. 4 is a transverse section of the air heater taken on the line 44 in Fig. 2, with parts broken adjacent side wall of the outside housing removed to show the baiiles that define the tortuous smoke passage at that side of the firebox.

Fig. 6 is a horizontalsection taken on the line 66 in Fig. 2, showing the heater in'plan view.

Fig. 7 is a horizontal section taken on the line 1-7 in Fig. 2. I

Fig. 8 is a sectional detail taken on the line 88 in Fig. 6, showing the disposition of the side and auxiliary outlets of the smoke flue, relative to the top walls of the outside and inter- I mediate housings.

.Fig. 9 is an enlarged sectional detaihtaken on the line 9-9 in Fig. 1, illustrating the manner of use of an electric motor for creating forced circulation of air through the heater.

Fig. 10 is a vertical section of a heater of an alternative form.

Fig. 11 is a front elevation and partial crosssection of the same.

Described in a general way, the present air heater comprises a firebox that is open at the front to receive fuel and to permit view of the flame as the fuel burns, as is characteristic of the use of the usual fireplace. Immediately surrounding the firebox, except at the front thereof, and spaced from the walls'thereof, is what is herein referred to as the intermediate housing. Likewise, immediately surrounding the said 'intermediate housing, except at the front thereof, and also spaced from the walls thereof, is what is herein referred to as the outside housing. The walls forming the firebox and those forming the intermediate housing are so spaced apart as to provide a chamber entirely about the firebox in which air will be heated by contact with the enclosing walls; cool air being admitted to this chamber through an opening or openings thereinto located at the front and immediately below the firebox and the heated air being discharged into the area to be heated through an opening immediately above the firebox.

Between the walls of the outside housing and walls of the intermediate housing and surrounding the latter, is a smoke chamber, equipped with baffles so arranged as to provide tortuous passages through which the smoke and gases from burning fuel may be diverted from direct flow to the chimney to additionally heat the air chamber.

The present structure is of unitary character and is so designed that it may be readily pushed into an open fireplace and thereby made ready for immediate use, utilizing the chimney of the fireplace for the disposition of smoke from its firebox, but not allowing heated air to be wasted out of the fireplace chimney.

Referring more in detail of the drawings:

In Figs. 1 and 2, I have illustrated a typical fireplace construction within which a heater embodied by this invention is applied. It is shown best in Fig. 2 that the fireplace comprises the usual form of combustion chamber I 0, which connects at the top with the chimney passage or fiue I I through a throat passage 12. The back of the combustion chamber It! comprises an upwardly and forwardly curved wall l3, terminating at the throat passage [2, and across the front and top of the combustion chamber the brickwork is supported by horizontal lintel l4. The width and height of the front opening into the fireplace combustion chamber is indicated in Fig. 1 in dotted lines at Him, and in Figs. 6 and '7 the opposite Side walls of the chamber ID are indicated at l5-l5 and are shown as being symmetrically inclined toward each other as they approach the back wall IS.

The present circulating air heater is built in such dimensions that when in place it substantially fills the combustion chamber of the fireplace as will be understood by reference to Figs. 2, 6 and '7. The unit is preferably constructed in its entirety of sheet metal of proper kind and gauge to meet requirements. In its preferred form of construction, it comprises a firebox enclosing a combustion chamber IE. The firebox is formed with a horizontal bottom wall 18, a back wall [9, a top wall 20 and opposite side walls 2I-2I .The sheet metal plates forming these several walls are welded together, or otherwise so joined, as to give the box the required strength, rigidity and air-tightness. The side walls 2 l-2l project somewhat below the opposite side edges of the bottom wall I8, thus to support the bottom wall above the floor surface of the fireplace and provide a passage immediately below wall 93 for entering air, and these side walls have their rear, lower corner portions cut away, as at 22 in Figs. 2 and '7, to provide lateral outlets for the flow of entering air from beneath the wall It to the opposite sides of the firebox as well as to the back thereof.

The back wall [9 of the firebox is upwardly and forwardly inclined substantially in accordance with the inclination of the back wall of the fireplace, as noted in Fig. 2, and its opposite side walls, likewise, are set substantially parallel with the side walls l5--l5 of the fireplace, as noted in Fig. 6. The top wall 20 of the firebox is downwardly and forwardly sloped, asseen in Fig. 2,

- control and adjustment of the damper.

for better retaining gases of combustion, and it has a downwardly and inwardly curved smoke guide 23 across its forward edge which also gives rigidity to this part of the structure.

Enclosing the unit is the outside housing, comprising a horizontal top wall 28, a back wall 29 and opposite side walls 3030. The back and side walls are set substantially parallel with the fireplace walls that are adjacent thereto, and preferably the walls of this outside housing are exteriorly covered with an insulating material such as sheet asbestos, indicated at 3|, to prevent outward dissipation of heat.

Disposed between the walls of the insulated outside housing and those of the inside firebox, is the intermediate housing. This housing, which is best shown in Figs. 2, 3 and '7, comprises a horizontal top wall 34, opposite side walls 3535 and a back wall 36. These walls are parallel with and spaced from the corresponding walls of the outside housing and firebox and as associated with the latter they enclose the previously mentioned air heating chamber that surrounds the firebox. As associated with the outside housing, the walls of the intermediate housing define the inner walls of the smoke chamber that is immediately within the walls of the outside housing.

At opposite sides and adjacent its top wall just back of the smoke guide flange 23, the firebox is equipped with outlets 38 leading through the air chamber and opening into the smoke chamber as shown best in Figs. 2, 3 and 5. Also the firebox of the heater is equipped centrally, in the top wall thereof, with a smoke outlet or fiue 40 that leads from the combustion chamber l6, upwardly through the

top walls

34 and 28 of the intermediate and outside housings and provides for a direct outflow of smoke to the fireplace chimney. This flue 40 is equipped at its upper end with a damper 4| that is fixed on a rotatably mounted rod 42 that extends horizontally to the front of the fireplace, as shown in Figs. 2 and 6, for the When the damper is open, smoke and gases may flow directly from the firebox to the chimney passage II, but when the damper is closed, as in Fig. 8, the smoke and gas will be caused to be laterally diverted through openings 43 that are provided in the opposite side walls of the flue 40 and outlets 38 in the side walls of the firebox, into the smoke chamber between the

housing walls

28 and 34, and will then be drawn laterally to opposite sides of the intermediate housing, then downwardly, then to the back of the unit, and finally upwardly to the fireplace flue, as presently will be fully described.

To fully understand the manner in which the heated air is controlled, and the means for the disposition of the smoke and gases from the unit, especially when the damper is closed, it is to be further explained that a flat metal plate 44 is applied vertically to the front of the unit as a closure member for the front of the fireplace combusion chamber, and to this plate the forward edges of the wall plates of the firebox, the intermediate housing and the outside housing are attached by welding or otherwise, as noted in Figs. 2 and 7. This front plate 44 has an opening 44 registered with the front opening of the firebox, and has an opening 45 across the bottom or lower edge for inflow of fresh or cool air to the passage that is directly below the bottom wall of the firebox. Also, it has a horizontally directed opening 46 directly above the top wall of the firebox for outflow or discharge of heated air into the room that is being heated.

The plate 44 is of such dimensions that-it extends sufficiently beyond the side and top walls of the outside housing to overlap with the fireplace walls about the entrance to the combustion chamber Hi; this overlap being shown-in Figs. 2, j

6 and 7, wherein it is shown also that a joint sealing material 41 is applied about the edges of the plate, at the inside, to effectively retain smoke and gases, and also prevent air intake through this joint.

It is also to be explained that the back wall plate of the intermediate housing extends from tight against the bottom surface of the fireplace chamber to the top Wall of the outside housing, as seen in Fig. 2, and the side walls of the intermediate housing extend to the back wall of the outside housing, as seen in Fig. 6, except at their lower corners, which, as in Fig. 5, are cutaway to provide openings 48 for the fiow of gases to the space between the back walls of the intermediate housing and outside housing.

Mounted between the side walls 38-30015 the outside housing and side walls -35 of the intermediate housing, in a manner as shown in Figs. 3 and 5, are baffles 58 and 5|. The bafiles 58 extend from the rear upper corners of the outside corners of the outside housing, downwardly and forwardly to the forward lower portions of the housing, then are turned directly downward, terminating somewhat above the lower edges of the side walls. The baffles 5| are spaced rearwardly from and below the baffles 50 and extend vertically upward from the fioor of the fireplace and have their upper end portions rearwardly inclined. The arrangement of bafiles 58 and 5|, at

each side of the heater, is like that at the other, and in each instance they provide smoke passages at opposite sides of the intermediate housing, which at their upper ends communicate with the open space between the

top walls

28 and 34, and at their lower ends communicate, about the lower ends of the bafiies 50, with passages that lead upwardly and rearwardly, between the baffles 50 and 5|, then turn downwardly over the upper ends of the baiiies 5| and connect through the side wall openings 48 with passages that are formed between the rear walls of the intermediate housing and outside housing, these passages being shown best in Fig. 4 and presently described.

It is shown in Figs. 2 and 3 that the top wall 28 of the outside housing is formed with an opening located in the top wall of the back flue comprised by the smoke chamber space that is between the back walls of the outside and intermediate housings, and it provides for the outflow to the fireplace fiue of that smoke and gas that is diverted through the

openings

43 and 38 by, the closing of the damper in flue 48.

In order to spread the flow of smoke that enters through the openings 48 over the back walls of the housings, for extraction of heat therefrom, I have extended the side walls 35-35 of the intermediate housing to the back wall of the outside housing, as shown in Fig. 5, and have placed baiiies 58-58 and 59 between the

walls

29 and 36 as shown in Fig. 4, wherein it is noted that the bafiles 58-58 are extended horizontally from the opposite outer edges of the back wall 36, at the same horizontal level a short distance above the fireplace floor, and are spaced at their inner ends to provide an open passage 68 between them. The baiiie 59 is disposed in a horizontal direction, at a distance above baffles 58-58, and has downwardly sloping opposite end portions that terminate away from the side edges of the back wall to provide open passages 6l-6l. Smoke that is drawn laterally from the flue 48 through the openings 43, and flows downwardly and through the tortuous passages at the opposite sides of the intermediate housing, enters through the passages 48, to the back side of the housing from opposite sides and beneath the baflies 58-58,

' flows inwardly and upwardly through passage 68 then spreads laterally and flows upward through the passages 6 l-6l and then out through the top opening 55 to the fireplace flue or chimney.

It will be understood that by so diverting the flow of hot gas and smoke, practically all heat therein will be dissipated to the housing walls and will be extracted by the air that is to be heated and discharged into the room through the front opening 46. Y

Assuming the device to be so constructed, and to be applied within a fireplace as shown, or to be outside a fireplace and connected to a flue by a stovepipe, its mode of use would be as follows:

A fire is built'in the firebox chamber [6 in the usual manner, the damper 4| being in its full open position. After a good fire has been started and the chimney fiue has been sufiiciently heated to maintain a good upward draft, the damper may then be closed. This will cause the smoke and hot gases of combustion to be diverted about the air heating chamber by flow laterally across the top 34, and also under wall 28, and down the opposite sides to the back and then upwardly to the chimney through opening 55. This will quickly and eifectively heat the air chamber both from inside and outside.

Air that enters the air chamber through the front opening 45 fiows rearwardly and thence is distributed to the opposite sides and to the back of the firebox, flows upwardly and then across the top of the firebox to the outlet 46 through which it is discharged to the area or room to be heated.

I have shown also in Figs. 1 and 3 that there are openings -65 in the bottom edges of the front plate for admitting cool air into the spaces between the side walls of the firebox and intermediate housing. These openings might ordinarily be closed, but are rovided for use in the event that forced air circulation is desired. In event of use of these openings for forced air circulation, then the central opening 45 would be covered by a plate 61 as has been shown in the sectional detail of Fig. 9, which illustrates the use of an electric motor and fan for creating a forced flow of air.

It is shown in Fig. 7 that the wall 35 has a laterally offset portion 35:: closing ofi the smoke passage and giving added space for the reception of the motor 68.and the fan 69 mounted on the motor shaft.

With the understanding that the openings 65-65 were uncovered, and that openin 45 was covered by the plate 61, it will then be understood that operation of the fans will draw in outside air and forcibly deliver it through opening 46.

When the forced air system is not being used, it is desirable that the openings 65 be covered in order to prevent short circuiting of cool air direct to the outlet 46.

In Figs. 10 and 11, I have illustrated an alternative construction which, in addition to the features disclosed in the device as already described, includes also an air chamber that entirely surrounds the smoke chamber. In these views, part that correspond to parts already described have been given the same reference numerals and the description pertaining thereto will not be repeated.

The alternative structure is characterized by the provision of an air space or chamber that entirely surrounds the smoke chamber, so that heat that is transmitted from the smoke to the outer wall of the smoke chamber may be utilized. The housing which encloses this unit is formed with a bottom wall 15, a back wall "at, top wall 71, and opposite side walls 'i,8l8. These various walls coaot respectively with the

walls

18, 29, 28, 30 and 30, to provide the air spaces and passages that surround the smoke chamber. It is shown in Fig. that the air that is to be heated enters the heater at the front through opening 45, flows rearwardly beneath the bottom l8 of the firebox, and then upwardly through the two fiues 80 and BI provided at the rear of the firebox, and also upwardly through the two flues $2 and 83 at each side of'the firebox, then forwardly through the two passages 84 and 85 to the front opening 46. It is shown in Fig. 10 that the passage 84 is connected with the outlet 46 by a passage 88.

In this device, I have illustrated the device as being equipped with a sliding damper Ala; in lieu of the pivoted damper, and it is adapted to be shifted to and from closed position by means of a rod the that extends to the front of the unit.

I have also shown the device as being equipped for forced air circulation. To accomplish this, an electric air blower 90 is shown as being located within the front opening 45' to draw in air and to forcibly deliver it toward the rear of the unit. Bafiles to effect a proper distribution of air could be employed as required. Preferably the blower would be located centrally between opposite side walls and near the front and the opening 45' would be of limited size.

Devices of this character have proven to be exceptionally efilcient and economical. They may be made in various sizes to adapt them for use in small or large fireplaces and may be changed in proportionate dimensions without departing from the spirit of the invention.

Heaters of this kind are especially useful for quick heating, for example, in cool summer evenings, when it is not practical or desirable that the housing heating plant be operated.

While I have not so illustrated it, it is to be understood that the present unit might be used as an ordinary heating stove by connecting it with a chimney or flue by means of a stove pipe leading from the outlet 55.

Having thus described my invention, what I claim as new therein and desire to secure by Letters Patent is:

l. A unitary, portable, circulating air heater, adapted to be disposed within a fireplace combustion chamber and to close the front thereof, said heater comprising a firebox that is open to the front of the fireplace, an air heating chamber immediately surrounding the firebox except at the front thereof, and. having an air inlet into the lower portion of the chamber below the firebox and having an air outlet from the upper portion thereof above the firebox, the air inlet being enclosed along opposite sides to conduct incoming air below the firebox to near the back of the chamber for upflow at sides and back thereof, thence to be discharged through the air outlet, a smoke chamber enclosing the back, sides and top walls of the air heating chamber, and a top opening from the smoke chamber into the fireplace combustion chamber for flow of smoke to the fireplace flue, a flue for the firebox providing direct outflow of smoke and gases to the fireplace flue and having lateral outlets into the smoke chamber, a damper for the firebox flue adjustable to an open position for direct flow of smoke to the fireplace flue, and adjustable to a closed position for diverting smoke and gases to the fireplace flue through said smoke chamber, bafiles disposed in the smoke chamber to direct the circulation of smoke and gases therethrough downwardly at the sides of the firebox and to the back thereof, and bafiles on the back wall of the smoke chamber being so disposed as to cause the smoke and gases that enter from opposite sides at the bottom to flow upward through a central opening, thence to be diverted toward the opposite sides and subsequently to the outlet of the smoke chamber.

2. A heater of the character described comprising an open front firebox, an air heating chamber immediately surrounding the firebox at all sides except the open front, a smoke chamber immediately surrounding the air heating chamber, means for admitting cold air into the said air heating chambers below the firebox, means for outflow of air from the air heating chamber above the firebox, a flue from the top of the firebox for direct outflow oi smoke and gases, and having lateral openings into the smoke chamber, a smoke outlet for the smoke chamber and a damper for the flue adjustable to open position for permitting direct outflow of smoke and gases and to closed position for diverting flow through the said lateral outlets to the smoke chamber; said smoke chamber having baflles disposed therein to direct the circulation of smoke and gases therethrough downwardly at the sides of the firebox and to the back thereof, and baffles on the back wall of the smoke chamber being so disposed as to cause the smoke and gases that enter from the opposite sides at the bottom to flow upward through a central opening, thence to be diverted toward the opposite sides and sub sequently to the outlet of the smoke chamber.

NEWMAN T. BROWN.

References Cited in the flle of this patent UNITED STATES PATENTS Number Name Date 708,563 Krauter Sept. 9, 1902 1,287,815 Anderson Dec. 17, 1918 1,387,252 Gage Jan. 8, 1935 2,131,763 Sroat Oct. i, 1938 2,231,178 Dollinger Oct. 5, 1943 2,360,611 Leonard Oct. 17, 194-4 FOREIGN PATENTS Number Country Date 255,342 Switzerland Jan. 17, 1949