JP7714247B2 - stove - Google Patents

Description

The present invention relates to a stove that burns solid fuel such as firewood and is used primarily for heating purposes, and in particular to a stove that preheats and supplies the combustion air required to burn the solid fuel.

Conventionally, a stove of this type is known, for example, from Japanese Patent Laid-Open Publication No. 2010-133697 (Patent Document 1).
This stove has a main body with a combustion chamber for burning solid fuel such as firewood or pellets, and combustion air is supplied to the combustion chamber of the main body to burn the solid fuel and generate combustion gas, which is exhausted from the chimney. The main body is equipped with a heat exchanger that exchanges heat between the combustion air and the combustion gas to warm and preheat the combustion air.

This heat exchange unit comprises a metal outer cylinder with a housing portion accommodated within the combustion chamber, an inlet for introducing combustion air from outside the main body, and an outlet for discharging combustion air toward the combustion chamber; and a metal inner cylinder with one end opening located on the inlet side of the outer cylinder and the other end opening located on the outlet side of the outer cylinder, the outer surface of which is spaced apart from the inner surface of the outer cylinder and inserted into the outer cylinder. The outer and inner cylinders form a double-cylinder section. One end opening of the inner cylinder is connected to a chimney, and combustion air is supplied to the combustion chamber through the outer cylinder. Solid fuel is burned in this combustion chamber to generate combustion gas, which is then exhausted through the inner cylinder and out the chimney. During the combustion of this solid fuel, heat exchange between the combustion air and the combustion gas occurs in the double-cylinder section formed by the outer and inner cylinders of the heat exchange unit, warming and preheating the combustion air and improving the combustion efficiency of the solid fuel.

JP 2010-133697 A

In the conventional stoves described above, heat exchange between the combustion air and the combustion gas takes place in the double-cylinder section formed by the outer and inner cylinders of the heat exchange section, and the combustion air is heated and preheated to improve the combustion efficiency of the solid fuel.However, since the combustion air only comes into contact with the inner surface of the outer cylinder and the outer surface of the inner cylinder, there is a problem that the heat exchange efficiency is not necessarily good.
The present invention has been made in consideration of these problems, and aims to provide a stove that improves the heat exchange efficiency between combustion air and combustion gas, and improves the combustion efficiency of solid fuel.

In order to achieve the above object, the stove of the present invention comprises a main body having a combustion chamber for burning solid fuel, and a heat exchanger that supplies combustion air to the combustion chamber of the main body to combust the solid fuel and generate combustion gas, which is exhausted from a chimney, and that exchanges heat between the combustion air and the combustion gas to heat the combustion air.
The heat exchange unit is configured to include a metal outer cylinder having an accommodation portion accommodated within the combustion chamber and having an inlet for introducing combustion air from the outside of the main body and an outlet for discharging combustion air toward the combustion chamber, and a metal inner cylinder having one end opening located on the inlet side of the outer cylinder and the other end opening located on the outlet side of the outer cylinder, the outer surface of which is inserted into the outer cylinder with a space between the inner surface of the outer cylinder, and a plurality of metal pipes are installed at required intervals between a wall portion constituting the accommodation portion of the outer cylinder and a corresponding wall portion constituting the inner cylinder, and metal pipes are installed on the outer surface of the outer cylinder that communicate with the inside of the pipes and have an opening into the combustion chamber. an outer opening is formed through the inner surface of the inner cylinder, an inner opening is formed on the inner surface of the inner cylinder that is connected to the inside of the tubular body and opens into the interior of the inner cylinder, one end opening and/or the other end opening of the inner cylinder is connected to the chimney, and when either one end opening or the other end opening of the inner cylinder is connected to the chimney, the other of the one end opening or the other end opening that is not connected to the chimney is closed, the space from the outer opening through the inner opening to the chimney is configured as a gas passage space through which combustion gas can pass, and the space between the inner surface of the outer cylinder and the outer surface of the inner cylinder, from the inlet to the outlet, is configured as an air passage space through which combustion air can pass.

Here, multiple tubes are provided at the required intervals, but the required intervals and number can be determined as appropriate. Furthermore, the connection between the inner tube and the chimney can be modified as appropriate, with one end opening and the other end opening of the inner tube each connected to a chimney, as shown in Figure 6(a), or with a chimney connected to one end opening of the inner tube and the other end opening closed, as shown in Figure 6(b), or with one end opening of the inner tube closed and a chimney connected to the other end opening, as shown in Figure 6(c).

As a result, during solid fuel combustion, combustion air flows in through the inlet of the heat exchanger's outer tube and out through the outlet, entering the combustion chamber and combusting the solid fuel. The combustion gas generated by this solid fuel combustion flows from the outer opening of the outer tube, through the tube, and into the inner tube via the inner opening. It then passes through the inner tube and is exhausted through the chimney. That is, the combustion gas passes through the gas passage space of the heat exchanger and is exhausted through the chimney, while the combustion air passes through the air passage space of the heat exchanger and is supplied to the combustion chamber. Heat exchange between the combustion air and the combustion gas occurs in this heat exchanger. This warms and preheats the combustion air. In this case, the combustion air contacts not only the inner surfaces of the outer tube and the inner tube in the air passage space, but also the surface of the tube. This increases the contact area with the area heated by the combustion gas compared to conventional systems, thereby improving heat exchange efficiency and, consequently, solid fuel combustion efficiency. Additionally, because the combustion gas passes through multiple tubes before entering the inner cylinder, the residence time is longer, ensuring that secondary combustion takes place in the gas passage space, further improving combustion efficiency.

If necessary, the main body is configured to include a metal bottom wall, a ceiling wall, and a side wall that surround the combustion chamber, and an opening that can be opened and closed by an opening/closing body is provided in the side wall and/or the ceiling wall to introduce solid fuel into the combustion chamber;
The bottom wall portion and/or the side wall portion of the main body are double-layered with wall plates to form an air flow space between the double wall plates through which combustion air can flow;
The outer cylinder is formed into a cylindrical shape having one opening and another opening, the one opening of the outer cylinder is disposed so as to face the outside of the main body and the other opening of the outer cylinder is disposed so as to face the air circulation space, the one opening constitutes the inlet, and the other opening constitutes the outlet,
An outlet for blowing combustion air from the air flow space into the combustion chamber is formed in the bottom wall and/or side wall of the main body that constitutes the air flow space.

This simplifies the structure by configuring the combustion air inlet at one opening of the outer casing and the outlet at the other opening. Furthermore, the combustion air is heated in the heat exchanger, flows out of the outlet of the outer casing, which forms the air passage space, into the air circulation space, and is then supplied into the combustion chamber through the outlet. In this case, the air circulation space is formed in the bottom wall and/or side wall of the main body, which is heated in the combustion chamber, so the combustion air is further heated here as it passes through. Furthermore, because the outlet is provided in the bottom wall and/or side wall of the main body, the outlet can be located in a location where solid fuel is more easily combusted than when the outlet is simply configured as the other opening of the outer casing, thereby improving combustion efficiency.

In this configuration, it is effective to, if necessary, form the bottom wall portion double, comprising a lower wall plate and an upper wall plate disposed a predetermined distance above the lower wall plate, forming the air circulation space between the lower and upper wall plates, joining the other opening side of the outer cylinder to the upper wall plate and erecting the outer cylinder on the upper wall plate, forming an upper through-hole in the ceiling wall portion through which one opening of the outer cylinder faces outward from the main body, and forming a lower through-hole in the upper wall plate of the bottom wall portion through which the other opening of the outer cylinder faces the air circulation space, and forming the air outlet between the edge of the upper wall plate facing the side wall portion and the side wall portion. Because the air outlet is formed along the side wall portion and combustion air is blown from bottom to top, the solid fuel is supported more stably against the bottom wall portion, facilitating combustion and thereby improving combustion efficiency.

If necessary, the main body can be configured to have a front and a back side, with the opening provided in the front side wall of the main body, the outer and inner cylinders provided in contact with or close to the back side wall, and the outlet formed between the edge of the front upper wall plate and the front side wall. Combustion air is supplied from the front side to the back side, ensuring reliable combustion of solid fuel.

Furthermore, if necessary, the edge of the upper wall plate that forms the air outlet can be curved and raised so that it convexly faces the front when viewed from the side. The combustion air from the air outlet is guided between the curved edge of the upper wall plate and the side wall portion and supplied to the combustion chamber, making it less likely for the air outlet to be blocked by solid fuel, ensuring more reliable combustion of the solid fuel.

Furthermore, if necessary, the upper wall plate can be provided with multiple support plates at predetermined intervals, each with a vertical surface direction and capable of supporting solid fuel. Because the solid fuel is placed on the upper edges of the comb-like support plates, combustion air can be more easily supplied from below, further ensuring the combustion of the solid fuel.

Furthermore, if necessary, the outer and inner cylinders may be formed cylindrically and arranged so that the center lines of the outer and inner cylinders are coaxial, and the plurality of pipes may be arranged so that their axes intersect and are perpendicular to the center lines of the outer and inner cylinders. This allows the combustion gases that have passed through the pipes to merge and concentrate in the center of the inner cylinder, effectively increasing the combustion temperature and further improving combustion efficiency.
In this case, it is effective to provide a plurality of the tubes at equal intervals along the centerline direction of the outer and inner tubes to form a tube array, and to provide a plurality of tube arrays at required intervals along the circumferential direction of the outer and inner tubes. This allows the tubes to be arranged in a matrix around the inner tube, so that the combustion air passing through the air passage space comes into even contact with the outer tubes, thereby improving the efficiency of heat exchange with the combustion gas. Furthermore, since the outer openings communicating with the tubes are formed in a matrix on the outer surface of the outer tube, the combustion gas is introduced evenly from the periphery of the outer tube into the inner tube, stabilizing the flow of combustion gas, thereby further ensuring the combustion of solid fuel.

According to the present invention, heat exchange occurs between the combustion air and the combustion gas in the heat exchange section. In this case, the combustion air not only contacts the inner surfaces of the outer and inner tubes in the air passage space, but also the surface of the tubes. This increases the contact area with the area heated by the combustion gas compared to conventional methods, thereby improving heat exchange efficiency and, accordingly, the combustion efficiency of the solid fuel. Furthermore, because the combustion gas passes through multiple tubes before entering the inner tube, its residence time is increased, ensuring secondary combustion in the gas passage space, further improving combustion efficiency.

1 is a perspective view showing a stove according to an embodiment of the present invention; 1 is a front cross-sectional view showing a stove according to an embodiment of the present invention. 1 is a side cross-sectional view showing a stove according to an embodiment of the present invention. 1 is a plan cross-sectional view showing a stove according to an embodiment of the present invention. 1 is a partially cutaway perspective view showing a heat exchanger of a stove according to an embodiment of the present invention. 1A and 1B show the connection modes between the heat exchange unit and the chimney in a stove according to an embodiment of the present invention, in which (a) is a diagram showing one end opening and the other end opening of the inner tube connected to the chimney, (b) is a diagram showing one end opening of the inner tube connected to the chimney and the other end opening closed, and (c) is a diagram showing the other end opening of the inner tube connected to the chimney and the one end opening closed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A stove according to an embodiment of the present invention will now be described in detail with reference to the accompanying drawings.
1 to 5, a stove S according to an embodiment of the present invention comprises a main body 1 having a combustion chamber E for burning a solid fuel W such as firewood, and combustion air is supplied to the combustion chamber E of the main body 1 to combust the solid fuel W, generating combustion gases that are exhausted from a chimney 2. The main body 1 is provided with legs 3 for supporting it.

In more detail, the main body 1 includes a bottom wall 4, a ceiling wall 5, and a side wall 6 made of a metal such as iron that surround the combustion chamber E, and has a front and a back. The bottom wall 4 and the ceiling wall 5 are semicircular when viewed from above, with the back side curved. The chimney 2 is erected above the ceiling wall 5, in the center of the back. The side wall 6 is located between the bottom wall 4 and the ceiling wall 5, with the back side side wall 6 curved to match the curved shapes of the bottom wall 4 and the ceiling wall 5, and the front side side wall 6 is flat. The side wall 6 and/or the ceiling wall 5 (the front side side wall 6 in this embodiment) have an opening 8 that can be opened and closed by an opening/closing body 7 to introduce solid fuel W into the combustion chamber E. The opening/closing body 7 is a door that can be opened and closed by a hinge.

The stove S according to this embodiment is equipped with a heat exchanger K that heats the combustion air by exchanging heat between the combustion air and the combustion gas. The heat exchanger K is comprised of an outer cylinder 10 made of a metal such as iron, which has an accommodation area Ka accommodated within the combustion chamber E and an inlet 11 through which combustion air flows in from outside the main body 1 and an outlet 12 through which combustion air flows out toward the combustion chamber E; and an inner cylinder 20 made of a metal such as iron, which has one end opening 21 located on the inlet 11 side of the outer cylinder 10 and the other end opening 22 located on the outlet 12 side of the outer cylinder 10, and which is inserted into the outer cylinder 10 with its outer surface spaced apart from the inner surface of the outer cylinder 10. The outer cylinder 10 and inner cylinder 20 are cylindrical and are arranged so that the center lines P of the outer cylinder 10 and inner cylinder 20 are coaxial.

In the heat exchange section K, multiple metal tubes 30 are installed by welding or other means at required intervals between the wall portion constituting the housing portion Ka of the outer tube 10 and the corresponding wall portion constituting the inner tube 20. An outer opening 31 is formed on the outer surface of the outer tube 10, which communicates with the interior of the tubes 30 and opens to the combustion chamber E, and an inner surface of the inner tube 20, which communicates with the interior of the tubes 30 and opens to the interior of the inner tube 20. Each of these multiple tubes 30 is arranged so that its axis Q intersects and is perpendicular to the center line P of the outer tube 10 and inner tube 20. The multiple tubes 30 are arranged at equal intervals along the center line P of the outer tube 10 and inner tube 20, forming a tube row of the tubes 30. This tube row is arranged in multiple rows at required intervals circumferentially around the outer tube 10 and inner tube 20. In this embodiment, each tube row (L1-L5) is made up of five tubes 30, for a total of five rows. As shown in Figure 4, adjacent tube rows (L1-L5) are spaced two rows to the left and right of each other at intervals of θ (60°) from one tube row (L1: a tube row in which the outer openings 31, described below, face forward).

The one end opening 21 and/or the other end opening 22 of the inner cylinder 20 are connected to the chimney 2, and when either the one end opening 21 or the other end opening 22 of the inner cylinder 20 is connected to the chimney 2, the other of the one end opening 21 or the other end opening 22 that is not connected to the chimney 2 is closed with a metal closing side plate 23. That is, the present invention can employ an embodiment in which both the one end opening 21 and the other end opening 22 of the inner cylinder 20 are connected to the chimney 2 as shown in FIG. 6(a); an embodiment in which the one end opening 21 of the inner cylinder 20 is connected to the chimney 2 and the other end opening 22 is closed with a closing side plate 23 as shown in FIG. 6(b); or an embodiment in which the other end opening 22 of the inner cylinder 20 is connected to the chimney 2 and the one end opening 21 is closed with a closing side plate 23 as shown in FIG. 6(c). In this embodiment, as shown in Figures 1 to 3, one end opening 21 of the inner cylinder 20 is connected to the chimney 2 via a connecting pipe 24, and the other end opening 22 is closed (the embodiment shown in Figure 6(b)).

As a result, in this embodiment, the space extending from the outer opening 31 through the inner opening 32 to the chimney 2 is configured as a gas passage space G through which combustion gas can pass, and the space between the inner surface of the outer cylinder 10 and the outer surface of the inner cylinder 20, extending from the inlet 11 to the outlet 12, is configured as an air passage space Aa through which combustion air can pass.

The bottom wall 4 and/or side wall 6 (bottom wall 4 in this embodiment) of the main body 1 are formed with two layers of wall plates, and an air flow space Ab is formed between these two layers of wall plates, allowing combustion air to flow through. In other words, the bottom wall 4 is formed with two layers, including a lower wall plate 4a and an upper wall plate 4b located a predetermined distance above the lower wall plate 4a, and an air flow space Ab is formed between the lower wall plate 4a and the upper wall plate 4b.

In the heat exchange section K, the outer cylinder 10 is cylindrically formed with one opening 13 and the other opening 14. The one opening 13 faces the outside of the main body 1, and the other opening 14 faces the air circulation space Ab. The inlet 11 is formed by the one opening 13, and the outlet 12 is formed by the other opening 14. The outer cylinder 10 and inner cylinder 20 are disposed in contact with or adjacent to the side wall portion 6 on the rear surface of the main body 1, and the outer cylinder 10 is erected by joining the other opening 14 side of the outer cylinder 10 to the upper wall plate 4b. An upper through-hole 15 is formed in the ceiling wall portion 5, through which the one opening 13 of the outer cylinder 10 faces the outside of the main body 1, and a lower through-hole 16 is formed in the upper wall plate 4b of the bottom wall portion 4, through which the other opening 14 of the outer cylinder 10 faces the air circulation space Ab. One opening 13 of the outer cylinder 10 protrudes slightly from the ceiling wall 5, and its outer periphery is welded to an upper through-hole 15 in the ceiling wall 5, while the edge of the other opening 14 of the outer cylinder 10 is welded to a lower through-hole 16 in the upper wall plate 4b of the bottom wall 4. The outer cylinder 10 is also installed so that the outer opening 31 of the tube row L1 faces forward.

As a result, the outer cylinder 10 is fixed to the bottom wall 4 and ceiling wall 5, the inner cylinder 20 is supported by the outer cylinder 10 via the pipe body 30, and the chimney 2 is supported by the inner cylinder 20 via the connecting pipe 24, so that the inner cylinder 20 and chimney 2 can be securely supported on the main body 1.

Furthermore, the bottom wall 4 and/or side wall 6 (bottom wall 4 in this embodiment) of the main body 1, which constitutes the air flow space Ab, has an air outlet 40 formed therein for blowing combustion air from the air flow space Ab into the combustion chamber E. The air outlet 40 is formed between the side wall 6-side edge 41 of the upper wall plate 4b. In this embodiment, the air outlet 40 is formed between the front-side edge 41 of the upper wall plate 4b and the front-side side wall 6. Also, as shown in FIG. 3, the end 42 of the edge 41 of the upper wall plate 4b that forms the air outlet 40 is curved upward so as to be convex toward the front when viewed from the side.

Furthermore, the upper wall plate 4b is provided with multiple support plates 50 at predetermined intervals, each capable of supporting solid fuel W and with its surface oriented vertically.

Therefore, when burning solid fuel W, such as firewood, using the stove S according to this embodiment, the opening/closing member 7 is opened, and the solid fuel W is introduced into the combustion chamber E through the opening 8 and ignited, as shown in FIGS. 1 to 4. During combustion of the solid fuel W, combustion air flows into the heat exchanger K through the inlet 11 of the outer cylinder 10, flows out of the outlet 12 of the outer cylinder 10 into the air flow space Ab, and is then supplied to the combustion chamber E through the outlet 40. Combustion gases generated by the combustion of the solid fuel W pass from the outer opening 31 formed in the outer cylinder 10 through the tubular body 30 and the inner opening 32 into the inner cylinder 20, and are then exhausted through the inner cylinder 20 through the chimney 2. Specifically, the combustion gases pass through the gas passage space G of the heat exchanger K and are exhausted from the chimney 2, while the combustion air passes through the air passage space Aa and the air flow space Ab of the heat exchanger K and is supplied to the combustion chamber E. Heat exchange between the combustion air and the combustion gas occurs in the heat exchanger K. As a result, the combustion air is heated and preheated. In this case, the combustion air not only contacts the inner surfaces of the outer and inner cylinders 10 and 20 in the air passage space Aa, but also the surface of the tubes 30. This increases the contact area with the area heated by the combustion gas compared to conventional systems, thereby improving heat exchange efficiency and the combustion efficiency of the solid fuel W. Furthermore, because the combustion gas enters the inner cylinder 20 through multiple tubes 30, its residence time is increased, ensuring secondary combustion in the gas passage space G, further improving combustion efficiency.

Furthermore, each of the multiple tubes 30 is arranged so that its axis Q intersects and is perpendicular to the center line P of the outer tube 10 and inner tube 20. Therefore, combustion gas passing through each tube 30 converges and concentrates at the center of the inner tube 20, effectively raising the combustion temperature and further improving combustion efficiency. Furthermore, the tube rows (L1-L5) of the tubes 30 are arranged in multiple rows at required intervals along the circumferential direction of the outer tube 10 and inner tube 20. Therefore, the tubes 30 are arranged in a matrix around the inner tube 20. Therefore, combustion air passing through the air passage space Aa comes into contact with the outer tubes evenly, thereby improving heat exchange efficiency with the combustion gas. Furthermore, the outer openings 31 communicating with the tubes 30 are formed in a matrix on the outer surface of the outer tube 10. Therefore, combustion gas is guided evenly from the periphery of the outer tube 10 into the inner tube 20, stabilizing the flow of combustion gas. This also ensures more reliable combustion of the solid fuel W.

Furthermore, in this case, the air flow space Ab is formed in the bottom wall 4 and/or side wall 6 (bottom wall 4 in the embodiment) of the main body 1, which is heated by the combustion chamber E. This further heats the combustion air as it passes through. Furthermore, since the outlet 40 is provided in the bottom wall 4 and/or side wall 6 (bottom wall 4 in the embodiment) of the main body 1, the outlet 40 can be located in a location where the solid fuel W is more easily combusted than when the outlet 40 is simply configured as the other opening 14 of the outer cylinder 10, thereby improving combustion efficiency. In the embodiment, the outlet 40 is formed between the edge 41 of the front upper wall panel 4b and the front side wall 6. This allows combustion air to be supplied from the front side to the rear side, ensuring reliable combustion of the solid fuel W. Furthermore, since the outlet 40 is formed along the side wall 6 and the combustion air is blown from bottom to top, the solid fuel W is more stably supported against the bottom wall 4, further facilitating combustion. This also improves combustion efficiency.

Furthermore, the end 42 of the edge 41 of the upper wall plate 4b that forms the air outlet 40 is curved and raised so that it convexly faces the front when viewed from the side. This allows the combustion air from the air outlet 40 to be guided between the curved end 42 of the upper wall plate 4b and the side wall portion 6 and supplied into the combustion chamber E, making it less likely for the air outlet 40 to be blocked by the solid fuel W and ensuring more reliable combustion of the solid fuel W. Furthermore, because the solid fuel W is placed on the upper edge of the comb-tooth-shaped support plate 50, combustion air is more easily supplied from below, further ensuring more reliable combustion of the solid fuel W.

In the above embodiment, the heat exchange section K has multiple tubes 30 spaced at a required distance from each other, but the required distance and number of tubes may be determined as appropriate. In the above embodiment, the inner tube 20 and the chimney 2 are connected to one end opening 21 of the inner tube 20 and the other end opening 22 is closed, as shown in Figures 1 to 3 and 6(b). However, this is not necessarily limited to this. As shown in Figure 6(a), the one end opening 21 and the other end opening 22 of the outer tube 10 may be connected to the chimney 2, respectively. Alternatively, as shown in Figure 6(c), the one end opening 21 of the inner tube 20 may be closed and the chimney 2 may be connected to the other end opening 22. This may be modified as appropriate. Furthermore, in the above embodiment, the outer tube 10 and the inner tube 20 are erected on the bottom wall 4, but this is not necessarily limited to this. For example, they may be installed between the side walls 6.

In addition, in the above embodiment, the air flow space Ab and the air outlet 40 are provided in the bottom wall 4, but this is not necessarily limited to this. They may be provided in both the bottom wall 4 and the side wall 6, or in the side wall 6 (see Figure 6), and modifications may be made as appropriate. The position of the air outlet 40 may also be determined as appropriate. Furthermore, the shape of the main body 1 is not limited to the above-mentioned shape. For example, the bottom wall 4, ceiling wall 5, and side wall 6 may be connected to form a rectangular or cylindrical shape, or any other shape. Furthermore, the opening 8 opened and closed by the opening/closing body 7 may be provided not only in the side wall 6 but also in the ceiling wall 5.

Furthermore, in the above embodiment, the bottom wall 4, ceiling wall 5, and side wall 6 are made of metal, but this is not necessarily limited to this. As long as the heat exchanger K is made of metal, it may be made of any heat-resistant material, such as stone or ceramic. Furthermore, in the above embodiment, the solid fuel W is not limited to firewood, but can of course be any material, such as peat, coal, lignite, bituminous coal, anthracite, coke, briquettes, wood pellets, sawdust charcoal, charcoal, wax, or various solid fuels. In short, those skilled in the art will readily be able to make numerous modifications to these exemplary embodiments without substantially departing from the novel teachings and advantages of the present invention, and these numerous modifications are within the scope of the present invention.

S stove W solid fuel 1 main body E combustion chamber K heat exchange section Ka accommodation area 2 chimney 3 legs 4 bottom wall section 4a lower wall plate 4b upper wall plate 5 ceiling wall section 6 side wall section 7 opening/closing body 8 opening 10 outer cylinder 11 inlet 12 outlet 13 one opening 14 other opening 15 upper through-hole 16 lower through-hole 20 inner cylinder 21 one end opening 22 other end opening 23 closing plate 24 connecting pipe 30 pipe body 31 outer opening 32 inner openings L1 to L5 pipe body row G gas passage space Aa air passage space Ab air circulation space 40 outlet 41 edge 42 end 50 support plate

Claims (8)

A stove comprising a main body having a combustion chamber for burning solid fuel, and a heat exchanger that supplies combustion air to the combustion chamber of the main body to combust the solid fuel, generating combustion gas and exhausting it from a chimney, and that exchanges heat between the combustion air and the combustion gas to heat the combustion air,
The heat exchange unit is configured to include a metal outer cylinder having an accommodation portion accommodated within the combustion chamber and having an inlet for introducing combustion air from the outside of the main body and an outlet for discharging combustion air toward the combustion chamber, and a metal inner cylinder having one end opening located on the inlet side of the outer cylinder and the other end opening located on the outlet side of the outer cylinder, the outer surface of which is inserted into the outer cylinder with a gap between the inner surface of the outer cylinder, a plurality of metal pipes are installed at required intervals between a wall portion constituting the accommodation portion of the outer cylinder and a corresponding wall portion constituting the inner cylinder, and outer openings communicating with the inside of the pipes and opening into the combustion chamber are provided on the outer surface of the outer cylinder. a space extending from the outer opening through the inner opening to the chimney is configured as a gas passage space through which combustion gas can pass, and a space between the inner surface of the outer cylinder and the outer surface of the inner cylinder, from the inlet to the outlet, is configured as an air passage space through which combustion air can pass. the main body is configured to include a metal bottom wall portion, a ceiling wall portion, and a side wall portion that surround the combustion chamber, and an opening that can be opened and closed by an opening/closing body is provided in the side wall portion and/or the ceiling wall portion to introduce solid fuel into the combustion chamber;
The bottom wall and/or the side wall of the main body are double-walled to form an air flow space between the double wall plates through which combustion air can flow;
The outer cylinder is formed into a cylindrical shape having one opening and another opening, the one opening of the outer cylinder is disposed so as to face the outside of the main body and the other opening of the outer cylinder is disposed so as to face the air circulation space, the one opening constitutes the inlet, and the other opening constitutes the outlet,
2. The stove according to claim 1, wherein an outlet is formed in the bottom wall and/or side wall of the main body that forms the air circulation space, for blowing combustion air from the air circulation space into the combustion chamber. The stove of claim 2, characterized in that the bottom wall portion is formed in two layers, comprising a lower wall plate and an upper wall plate disposed a predetermined distance above the lower wall plate, the air circulation space being formed between the lower and upper wall plates, the other opening side of the outer tube being joined to the upper wall plate so that the outer tube is erected on the upper wall plate, one opening of the outer tube forms an upper through-hole in the ceiling wall portion, facing outward from the main body, the other opening of the outer tube forms a lower through-hole in the upper wall plate of the bottom wall portion, facing into the air circulation space, and the air outlet is formed between the edge of the upper wall plate facing the side wall portion and the side wall portion. The stove of claim 3, wherein the main body has a front and a back, the opening is provided in the front side wall of the main body, the outer and inner cylinders are provided in contact with or adjacent to the back side wall, and the air outlet is formed between the edge of the front upper wall plate and the front side wall. The stove described in claim 4, characterized in that the edge of the upper wall panel that forms the air outlet is curved and raised so that it is convex toward the front when viewed from the side. The stove described in claim 5, characterized in that the upper wall plate is provided with a plurality of support plates at predetermined intervals, each of which is capable of supporting solid fuel and has a surface direction aligned vertically. A stove as described in any one of claims 1 to 6, characterized in that the outer and inner cylinders are formed cylindrically and arranged so that their center lines are coaxial, and the multiple tubes are arranged so that their axes intersect and are perpendicular to the center lines of the outer and inner cylinders. The stove of claim 7, characterized in that a plurality of the tubes are arranged at equal intervals along the centerline direction of the outer and inner cylinders to form a tube row, and the tube rows are arranged in multiple rows at required intervals along the circumferential direction of the outer and inner cylinders.