CA1119496A - Stove construction - Google Patents

Abstract

STOVE CONSTRUCTION

Abstract of the Disclosure A stove construction including a firebox that defines a combustion chamber. Air is aupplied to the upper portion of the combustion chamber through a pre-heat manifold having outlet apertures spaced along the sides. Air is drawn from the atmosphere into the mani-fold where it is preheated and discharged in the form of jets toward the sloping side walls of the firebox and into the flow path of the waste gases of combustion.
Due to the restriction to flow caused by baffles located in the spaces between the sides of the manifold and the sloping sidewalls, a portion of the mixture of air and waste gases is directed downwardly along the surface of combustion plates, which are spaced from the walls of the firebox, back toward the primary com-bustion area. The waste gases are further combusted as they pass downwardly along the heated combustion plates. The recirculation achieves complete combus-tion of the waste gases.

Description

Back round of the Invention _ Stoves have recently come into increased use as a supplemen~al heat source for homes and commercial and industrial establishmen~s. To increase the effic-iency and reduce smokè emission, stoves have includedan air supply system in which air is drawn from the atmosphere and supplied to the upper end of the combus-tion chamber to aid in burning the combustible waste gases in a secondary combustion zone. Stoves, as utilized in the past, have also included an air heat-ing system in which air is drawn from the atmQsphere and passed in heat exchanga relation to the.firebox or stack~ and the heated air is discharged into the surround-ing xoom or enclosure to thereby provide heat in the form of convection as well as radiation~
Summary of _ e Invention The invention realtes to an improved stove construction. The stove inc~udes a firebox that defines a combustion chamber and aix is supplied from the atmos~
~0 phere to the upper portion of the combustion chamber through an elongated manifold or conduit having a plurality o outlet apertures spaced along its side~.
The heated air is discharged from the outlet ..
apertures toward the converging walls of the ~irebox so that the waste gases o combustion passing upwardly in the combustion chamber are directed into contact with the heated air jetting from ~he apertures in the mani-old. Baffles are provided between the manifold and the converging walls of the firebox to restrict the flow of gas to the stack and to recirculate a portion 4~3~

of the waste ga~es downwardly along combustion plates or shieldswhich are spaced inwardly of the walls of the fireboxO The flow of waste gases downwardly along the hot combustion plates perpetuates the combustion process and insures complete combustion of the waste gases~
Located above the combustion chamber is a heat exchange uni~ that includes a generally horizontal duct which provides communication between the combustion chamber and the atmosphere. Air is passed upwardly through a series of vertical passages which are in heat exchange relation ~o the duct, and the heated air is discharged from the upper end of the stove to thereby provide heating by convection7 as well as radiation, to the surrounding environment.
The stove of the invention has improved efficiency over stoves as used in the past, providing substantially complete combustion of the waste gases so that there is no smoke emit~ed from the unit.
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Heat is supplied to the adjoining environment both by radiation and convection due to the heat exchange system.
The stove is capable of completely combusting any type of fuel, such as wood, coal, ~rash, and the like.
Other objects and advantages will appear in the course of the ollowing description.
Description o the Drawings , The drawings illustrate the best mode presently contemplated o carrying out the invention.
In the drawings:
Fig. 1 is a perspective view o the stove construction of the invention;
Fig. 2 is a vertical section of the stove;
Fig. 3 is a section taken along line 3-3 of Fig. 2;

Fig. 4 iS a section ~aken along line 4-4 of Fig. 2; and Fig. 5 is an enlarged view of the section shown in Fig. 3.
Descrlption o:E the Preferred Embodiment ~ig. 1 illustrates the stove construction of the invention which includes an outer housing 1 which is supported on legs 2. The housing 1 includes a front wall 3, a pair o sidewalls 4 and a rear wall 5. An expanded ~etal or perforated top 6 is connected to the upper edges of the front walll sidewalls and end wall~
Located within the housing 1 is a steel fire-box 7, and as shown in Fig. 2, the firebox extends com-pletely across the front-to-rear dimension of the housi~g and a door 8, which is hinged to the front walL 3, pro~
vides access to the firebox.
The fire~ 7 includes a pair of sidewalls 9 which are spaced inwardly of ~he sidewal~s 4 o~ housing 1, and converging upper walls 10 are connected to each f the sidewalls 9. Connecting the bottom edges of sidewalls g is a bo~tom wall or floor 11 having a central opening which communicates with an ash box 12O
A series of gra~es13 extend longitudinally in ~ ;
spaced relation above ~he ash box, and a refractory lining 14 i5 located around the grates on bot.tom wall 11 and extends partially up the sidewalls 9.
Door 15 provides a¢cess to the ash box 12, and the door 15 has a central circular opening 16 which borders flange 17.and a damper plate 18 encloses the opening 16. As best shown in Fig. 2, an I-bolt 19 is secured within an opening in pla~e 18 and is threaded within a strap 20 secured to the door. By threading the I-bolt 19, the damper plate 18 can be moved toward and away from the door 15 to provide an opening through which air is admitted to the ash box and then to the combustion chamber within the firebox, In accordance with the in~ention, air is supplied from -the atmosphere to the upper end of the firebox 7 through a generally rectangular preheating manifold or conduit 21 which extends parti.ally across the firebox in a front-to-rear direction and de~ines a preheat chamber 22. The maniold 21 includes a top plate 23, a bottom plate 24 and a pair o side walls 25.
The manifold is mounted to the fireobx through a flange 26 which extends laterally from the rear end of the manifold and is bolted to the rear wall 5 o the fire-box 7. With thi~ construction, the manifold 21 can be withdrawn ~rom the combustion chamber by removal of the bol~s.
Air is supplied to the manifold 21 by a vertical tube or duct 27 which i5 mounted on the rear wall 5 and has an open lower end. The upper end of the tube communicates with ~he open rear end of manifold 21 so that air from the atmosphere will be drawn upwardly through the duc~ 27 into the manifold 21 and is preheated prior to introduction into the firebox.
The sidewa~ls ~5 of manifold or conduit 21 is provided with a mul~iplicity of apertures 28 which are spaced along the side walls and are located gener-ally centrally of the firebox. Diagonally extending baffles 29 are located within the rear portion of the manifold 21 and serve to direct the incoming air toward the center line of the manifold a~d thereby provide a more uniorm discharge o air rom the entire series of apertures 28. Due to the configuration of the manifold and the size and location o the aperturesr preheated air will be discharged from the mani~old 21 through the apertures 28 in a series of small jets, and the waste gases o~ combustion are directed by the convering walls 10 through the air jets to provide a scruhbing action and improve the combustion.

The total cross sec-tional area o the aper-tuxes 28 is less than the cross sectional area of the preheat chamber 22 so tha-~ the air being jetted through the apertures will have a substantial velocityO
The draft is controlled by providing restricted passages between the outer lateral edges of top plate 23 of manifold 21 and the upper inwardly bent edges 30 of combustion plates 31, as illustrated in Fig. 5. As seen in Fig. 4, the rear portion 32 of the top plate 23 is in close proximity to the converging side walls 10 of the firebox 7, while the forward portion 33 o~ the top plate 23 has a lesser width and terminates in spaced overlying relation to ~he edges 30 of the com~ustion plates 31. Gas can flow upwardly through the spaces between the edges 30 and the upper plate 23 of manifold 21, as illustrated by the arrows in ~ig~ 5.
The combustion plates 31 extend forwardly, beyond the orward end of manifold 21, and each combus-tion plate ~ncludes a diagonal uppe~ section 34 that is secured 1atwise to the diagonal wall 10, a central section 35 which is spaced in~ardly of the.side wall of the firebox, and a bent.lower edge section 35 that is welded to the side wall o~ the firebox~ The forward and rear ends o~ the combustion plates 31 are not attached to the wall of the firebox so limited gas circulation can o~cur within the space between the central section 35 and the wall of the firebox. Due to the construction o~ the invention and the recirculation o wasta gases, the combustion plates 31.are heated to extremely high temperatures, and the spacing of the combustion plates from the wall o the irebox will reduce the transfer of heat to the firebox, thereby retaining the high temperatures along the path o the recirculating waste gases to promote the combustion.
The forward end of maniold 21 is supported from the bent upper edges 30 of combustion plates 31 4~i by L-shaped hangers 37 that are secured to top plate 23 and rest on the respective edges 30.
In operation, air is draw.n into the manifold 21 through duct 27 and is jetted from the aper~ures 28 toward the sloping walls 34 and into the flow path of the waste gases of combustion. Due to the restriction caused by edges 30, a substantial portion of the mixture of air and waste gases is directed downwardly by the sloping walls 34 and is recirculated back down toward the primary combustion are~. As the gas recirculates downwardly, it passes over the hot surface of the cen-tral section 35 of the combustion plate to perpetuate the combustion of the waste gases. Thus, the construc-tion provides a continual recir~ulation of the waste gases to achieve impro~ed air-waste gas contact, result-ing in substantially complete. combustion of the com-bustible waste gases.
Supported above the firebox is a heat exchange unit 38 which extends across ths upper end of the hous-ing 1~ The heat exchange unit 38 includes a centralenclosure 39 having an open lower end which communicates with the upper end of the firebox. The central enclos-ure 39 has an opening 4~ in the front side which com-municate,s with a horiæontal trans.verse section 41 of outer enclosure 42~ and the ends o~ the transverse section 41 are in communication with the side sections 43 which are spaced laterally from the central enclosure 39. The rear ends of the side sections 43 are connected to a rear section 44 and an outlet 45 communicates with the rear section 44 and is connected to a chimney or stack 46 for discharge of the gases of combustion.
Air for space heating purposes is adapted to be drawn into the housing 1 through the open lower end of the housing and passes upwardly in the spaces 47 between the sides o~ the firebox 7 and the side,walls 4.
rrhe air then flows through the central passages 48 located between the central enclosure 39 and side sections 43 of outer enclosure 42, as well as through the side passages 49 which are located between the side sections 43 and sidewalls 4.
Heat is transferred from the hot yases of combustion to the air passing upwardly around the fire-box and through the heat exchange uni~ 38~ and the heated air is discharged upwardly through the expanded metal top 6 into the surrounding enVirQnment.
Improved combustion e~ficiency :is achieved by the air being je~ted ~hrough tlie apertures 28 which, in combination with the combustion plates 31, effects continual recirculation and combustion of the mixture of combustible gases and air to achieve substantially complete combustion of the combustible waste gases~
The stove of the invention can be used in any residential, commercial or industrial application, and has particular use as a source of supplemental ~, heating. Various types of materials such a~ wood, coal, waste, and the like can be used as fuel~

Claims (10)

The embodiments of the invention in which an exclu-sive property or privilege is claimed are defined as follows:

1. A stove construction, comprising a firebox defining a combustion chamber for primary combustion of combustible material, said firebox having an exhaust gas outlet in its upper end communicating with the combus-tion chamber, a preheat manifold disposed within the upper portion of the combustion chamber and defining a pre-heat chamber communicating with the atmosphere whereby air is drawn from the atmosphere into said pre-heat chamber and introduced into said combustion chamber, a wall connected to said firebox and spaced from the manifold to provide a passage therebetween for discharge of gases to the outlet, said wall sloping upwardly and inwardly in a direction toward said mani-fold, said manifold having a series of apertures communciating with said pre-heat chamber and facing said sloping wall, air being drawn from the atmosphere into said manifold being preheated in said pre-heat chamber and thereafter being discharged through said apertures toward said sloping wall and into contact with the waste gases of combustion passing upwardly through said passage, and a combustion member disclosed beneath said sloping wall and spaced inwardly from the wall of the firebox, said construction effecting a down-ward recirculation of the mixture of combustible waste gases and air along the combustion member toward the primary combustion region to achieve substantially complete combustion of the combustible waste gases.
2. The stove construction of claim 1, and including a pair of walls spaced on opposite sides of the manifold, each wall sloping upwardly and inwardly in a direction toward said manifold, said manifold

Claim 2 cont'd. . . . . .
having a series of apertures in opposite sides thereof, with each series of apertures facing the respective sloping wall, and a combustion combustion member disposed beneath each sloping wall.

3. The stove construction of claim 1, and including a flange extending inwardly from the upper edge of said sloping wall, the space between the inner edge of said flange and the manifold constituting said passage.

4. The stove construction of claim 3, wherein said manifold includes a tubular section that defines said pre-heat chamber and a top plate that extends laterally beyond the tubular section and is spaced above the inner edge of said flange, the space between the top plate and said inner edge constituting said passage.

5. The stove construction of claim 1, wherein said combustion member extends downwardly from said slop-ing wall to a level substantially below the manifold.

6. The stove construction of claim 5, wherein said combustion member comprises a plate that extends downwardly and inwardly fom said wall, said plate hav-ing an outwardly bent lower edge secured to said firebox.

7. The stove construction of claim 3, and including means to support the manifold from said flange.
8. A stove construction, comprising a firebox defining a combustion chamber, an exhaust gas outlet in the upper end of the firebox and communicating with the combustion chamber, a preheat manifold disposed in the upper portion of the combustion chamber, said manifold communicating with the atmosphere, a pair of sloping walls associated with the firebox and located on opposite sides of the manifold, each wall sloping upwardly and inwardly in a direction toward the manifold and spaced from the manifold to define a passage for the discharge of gases to said gas outlet, said manifold having a series of spaced apertures in opposite sides thereof,

Claim 8 cont'd. . . . . .
each series of apertures facing the respective sloping walls, air being drawn from the atmosphere into said manifold and being pre-heated in said manifold and there-after being discharged through said apertures toward the sloping walls and into contact with the waste gases of combustion passing upwardly in said passages, and a com-bustion plate disposed immediately beneath each sloping wall and extending downwardly to a level beneath said manifold, each combustion plate being spaced from the wall of the firebox said passages providing a restric-tion to the upward flow of said waste gas to the outlet to thereby effect a downward recirculation of the mixture of combustible waste gases and air within the combustion chamber along the combustion plates toward the primary combustion region to achieve substantially complete combustion of the combustible waste gases.

9. The stove construction of claim 8, wherein said manifold is elongated in a front-to-rear direction and has a generally rectangular cross section.

10. The stove construction of claim 9, wherein the front end of the manifold is closed, and the rear end of the manifold communicates with the atmosphere.