Tile stove

The invention relates to a combustion system for tile stoves as described in claim 1.

Background

In cold countries, heating is required most of the year. "Tile stove" as it is named in Norway, has served the people in the North for several centuries. Traditional stoves of the type of radiation/ convection type, have, compared with the tile stove, small abilities for holding the heat. A traditional wood-burning stove gives a high effect, but it gets rapidly cold as the flames die out. A tile stove is arranged on site with stove tile, olivine elements and mortar made of clay and sand. Each tile end is filled with tile stove application or clay application. As this, the tile stove is built up, shift after shift. This, which is one of several building methods, makes it possible to disassemble the tile stove and assemble it again if it is to be moved or the inner core is burnt-out. The tile stoves have duct systems leading the furnace gas up, such that give off heat is lead out into the room and over the entire height of the tile stove up to the duct outlet.

A weakness of the traditional tile stoves is that it is difficult to clean the pipes, due to they commonly are quarter-pole cut or quadrangular in relation to the mandrel/stem.

Another weakness is that soot plugs easily can arise in the duct at one of the sides, and thereby reduce the draft at this side. This will lead to that the draft at the other side increases and with the following temperature differences, a puncture easily can arise. This will reduce the operating time of the tile stove.

Some of the traditional tile stoves have heat ducts around the combustion chamber which leads to that the heat is drawn more rapid out of the room. If the choke is opened to early, before the tile stove has been warmed up, this reduces the combustion temperature of the fire. This leads to a more dirty combustion and contamination.

Another disadvantage with tile stoves is the weight. An average tile stove weighs from 800 kg to 200kg, which requires a separate fouWdation. In addition, they are generally very high, approximately 1.80 m to 2.20 m.

Of prior art in connection with combustion systems, the Norwegian patent 55874 is an example of a combustion by use of both primary and secondary combustion air.

Of prior art in connection with furnace gas ducts, the US-patent 4 526 319 discloses a tile stove with stacked elements with furnace gas ducts which are spiral shaped and which leads from the lower air inlet to the outlet in the upper part of the stove.

Object

The main object of the invention is thereby to provide a stove without the mentioned weaknesses and disadvantages. It is particularly important to reduce the weight and height in relation to the known stoves, such that it can be used in most of the homes, something that the invention provides. It is further an object to provide a stove with a improved combustion system than the earlier known, such that a more clean combustion is obtained, which leads to less ash, better utilisation of the combustion material, and less contamination.

Further it is an object to provide a stove with a duct system for the furnace gases which leads to increased transfer of heat out in the room and that facilitates the maintenance. This is obtained by using ducts having a circular cross-section and elements for leading the smoke up and down in the different ducts.

Finally it is an object to provide a stove which easily can be inspected for soot plugs.

The invention The invention is described in claim 1. With a stove like this, all the points mentioned above will be obtained.

The claims 2-11 describe particularly advantageous details by the invention. The invention can be divided into the following main drafts:

■ Convection

The heat is more rapid drawn out of the mandrel/stem from the stove, so that the heat enters the room more rapid. The convection ducts are arranged in the mandrel/stem, above the combustion chamber, with air intake above the fire, so that the temperature of the fire not is affected. This makes the stove more rapid reach the combustion temperature and leads to less contamination. The convection duct results in a larger surface and that the heat is faster drawn out of the mandrel /stem of the stove, by that cold air enters the slit at the front of the convection plate, and is heated by flowing through the convection duct/ which is located in the centre of the stove.

■ Lightening draft Make it easier for the user to start the fire.

■ Element for afterburning

The stove gets better utilisation of the combustion material by means of afterburning. The gas which is not entirely burned at the fire gets supplied heated secondary draft with a high temperature, so that the gas is set on fire again and continues to burn. This results in less soot and the pitch soot is burned up before it enters the ducts. The dry soot, which is remaining, will be easy to remove

with a soot brash. By correct use of the primary draft, the users will se on the afterburner if he/she is firing correct.

■ Circular ducts The first duct of the stove is oval to provide draft limiting and smoke gathering. Then the smoke goes up to a smoke switch which leads the smoke down to a smoke switch which leads the smoke upwards again in another duct. At the, top of the stove, the smoke passes a smoke collar which leads the out the heat from the convection duct. The smoke collar heats up outer parts of the mandrel /stem and the last part of the convection duct at the top. This result in the stove more rapid is warmed and by use of circular duct, the draft is smoother and there is less opportunity for soot plug to arise.

■ Ash bucket

The stove has an ash bucket at the bottom of the combustion chamber. The ash bucket is designed so that it can be lifted out and emptied, something which facilitates the clean of the stove. The combustion, as mentioned above, is so good that the ash bucket does not need to be emptied often.

■ Ash grate

The ash grate has a design, which makes the draft for making a fire, coming from below the ash bucket, is heated by the ash bucket holder. This results in the air being temperate and gets a high speed. Then the air goes to the centre of the grate and down in the ash bucket, which again will result in that ember present in the ash bucket will temperate the draft further and at the same time result in that the embers turns into soot. Next the heated air will go up between the slits of the grate and up in the fire. This will result in a minimum of ashes and a maximal temperate of the draft for making a fire.

In addition the stove can be covered by standard tiles/natural stones. The standard tiles/natural stones can be changed, so that the user can follow potential fashions. The tiles can have different shapes. The stove can also be covered with a stainless steel cloak, which can be profile adjusted and painted. It will then be easier to follow the potential fashion.

The stove has a long storing capacity for heat, when it has gained heat. After ten minutes of firing, heat can already be felt.

The design of the grate, results in that the draft is coming in the centre of the fire during lightening of a fire, instead of at the sides. This results in that the afterburning starts more rapid, as it is high temperature which heats the element for afterburning.

The stove can easily be controlled for soot plugs by feeling the surface temperature outside the smoke ducts under heating. If one side is warmer then the other, this can indicate soot plug.

A stove according to the invention can be made substantially easier than a traditional tile stove. The stove is built in a number of heights according to the user needs. The minimum embodiment can stand on a regular wooden floor. The weight can vary from 475 kg to 800 kg, depending on what the stove is covered with, and how high it is.

The advantageous combustion according to the invention is obtained by using both primary and secondary combustion draft, and by use of an element for afterburning.

Example

The invention will in the following be described with reference to the following Figurer, where:

Figure IA/ IB shows two examples of stoves according to the invention, Figure 2 shows a split-up principle view of a stove according to the invention, that Figure 3 shows a cross-section view of two elements for supply of draft of the stove of

Figure 2,

Figure 4 shows a perspective view of a base element of the stove of Figure 2,

Figure 5 shows a perspective view of a fill element of the stove of Figure 2,

Figure 6 shows a perspective view of a combustion chamber plate with lice and joints, with ash bucket holder and outward draft collar arranged in the combustion chamber plate and with an afterburner, of the stove of Figure 2, Figure 7 shows a perspective view of an element for afterburning of the stove of

Figure 2,

Figure 8 shows a grate, seen upside down, of the stove of Figure 2, Figure 9 shows burning plates, burning plate locks and vault plate of the stove of Figure 2,

Figure 10 shows a perspective view of a base element of the combustion chamber of the stove of Figure 2, ' '

Figure 11 shows a perspective view of door elements of a combustion chamber,

Figure 12 shows a perspective view of a convection plate of the stove of Figure 2, Figure 13 shows a perspective view of a lower element for direction of smoke, of the stove of

Figure 2, Figure 14 shows a perspective view of an element for continuing ducts, of the stove of Figure

2,

Figure 15 shows a perspective view of an upper element for direction of smoke, of the stove of Figure 2,

Figure 16 shows a perspective view of a smoke collar plate with soot hatches, of the stove

of Figure 2,

Figure 17 shows a perspective view of a smoke collar element, of the stove of Figure 2,

Figure 18 shows a perspective view of a top plate element, of the stove of Figure 2,

Figures IA and IB shows two different embodiments of the invention, respectively a stove for the living room and a stove for the kitchen. In the following example, references are made to the stove the living room. The shown stove can be _^ divided into fourteen building elements, as shown in detail in the Figures 5-18, which can be assembled above each other to create the stove. The building elements has a regular eight-sided shape. Figure 2 shows a principal view of the stove. The Figure shows how the stove is built up of different building elements. The different elements are, base element 1, fill element 20, combustion chamber, which includes a combustion chamber plate 30, a second fill element 81 for combustion chamber, and door elements 91, convection plate 101, a lower element 110 for direction of smoke, elements 120 for continuing ducts, upper elements 130 for direction of smoke, smoke collar plate 140, smoke collar element 150, and top plate 160. The elements are arranged above each other in the described order.

The stove can be divided into to parts, the combustion chamber and the duct system. The combustion chamber is created by a combustion chamber plate 30, a second fill element 81 for combustion chamber, door elements 91, a vault plate 73 (Figure 9), and is limited in the upper edge by the convection plate 101, and in addition a base element 1 and a fill element 20 for supply of draft to the combustion chamber. The duct system is created by a convection plate 101, a lower element 110 for direction of smoke, elements 120 for continuing ducts, upper element 130 for direction of smoke, smoke collar plate 140, and smoke collar element 150.

The separate elements of the combustion chamber are more detailed described in the Figures 3- 12, and for the duct system in the Figures 13-18.

The assembling of the combustion chamber will now be described.

Figure 3 shows a cross-section vieW through three elements, the base element 1, the fill element 20 and the combustion chamber plate 30, for supply of draft to the stove of Figure 2. The Figure has arrows indicating the direction of the draft. The Figure also shows the ash bucket holder 40, the draft collar 41, feet 44 of the ash bucket holder 40, which is adjustable, and how the grate 60 is arranged over the draft collar 41 and the ash bucket holder 40.

Between the outward draft collar 41 and the combustion chamber plate 30, a gasket (not shown) is arranged, for the draft collar 41 can expand in relation to the temperature. In the ash bucket holder 40, an ash bucket with a handle is placed (not shown). The base element 1 creates the base of the stove, at the same time as it is arranged a supply duct 2 for air. The air is supplied through the main duct 2, and distributed further into primary draft, which

enters through a duct centrally placed in the base element 1, and air (secondary draft) to the afterburner 50 which enters in to circular ducts 3.

At the base element 1, a fill element 20 is arranged, which function is to make space for a ash bucket holder 40, at a centrally arranged rectangular recess 21, and it has ducts 22 for forwarding air to a element for afterburning 50, in the example from now refer to as the afterburner 50.

The combustion chamber plate 30 is arranged on the fill element 20. The combustion chamber plate 30 has a centrally arranged recess 35 with an expansion 34 to hold an outward draft collar 41.

The purpose of the draft collar 41 is to guide primary draft from the main duct 2 to the grate 60 and the ash bucket holder 40. The air entering via the main duct 2 is guided in the space between the ash bucket holder 40 and the recess 21, the recess 35 and the draft collar 41, and to slits 42 in the ash bucket holder 42, which supplies the grate 60 with air, where the air is distributed further into the grate 60 and down into the ash bucket for combustion of coal. As the air is guided in the mentioned space, it is pre-heated of heat which the coal in the ash bucket gives off, before it enters through the grate 60, something which results in a better combustion. This results further on less ash in the ash bucket.

Regulation of primary air and secondary air is controlled by a damper 4. Closing the damper 4 will lead to more draft in the afterburner 50 and less draft in the grate 60. While much draft is needed at the fire when starting the fire, gradually more draft will be needed at the afterburner 50 to obtain a maximal combustion by means of afterburning. By this controlling, a combustion temperature is more rapid obtained, and the oxygen supply at the combustion material, in relation to amount and type.

Figure 4 shows a detailed perspective view of a base element 1 of the stove of Figure 2. The Figure has arrows indicating the direction of draft. The Figure shows the connection between the imbedded damper 4 and the regulation of primary and secondary air. The air ducts 3 are inclined to the centre height of the main duct 2. The size of the air ducts 3 is designed with respect to concentrate the draft to a narrower output surface. This will result in the draft being less compressed. This will be utilized when the draft reaches the afterburner 50.

Figure 5 shows a perspective view of a fill element 20 of the stove of Figure 2. The Figure has arrows indicating the direction of draft. The Figure shows the location of the centrally located rectangular recess 21 of the ash bucket holder 40, and the two circular generally holes 22, for continuing the air ducts 3.

Figure 6 shows a perspective view of a combustion chamber plate 30 with lice 31 and joints 32, with ash bucket holder 40 and outward draft collar 41 inserted in the combustion chamber plate 30, and with afterburner 50, for the stove of Figure 2. The Figure has arrows indicating the direction of draft. In the combustion chamber plate 30, the air ducts 22 continue into rectangular grooves 33 for the afterburner 50. This change is made to reduce the draft during heating up of the air to the

afterburner 50. At the combustion chamber plate 30, and around the combustion chamber, an exchangeable felt of Silcawool (not shown) is arranged. The purpose of which is to reduce the heat load at the bottom of the combustion chamber plate 30. The combustion chamber plate 30 has four joints 32, which extends from the corners of the recess for the ash bucket holder 40. To of the joints 32 extend through the rectangular recesses 33 for the afterburner 50. The joints are filled with clay and olivine sand. The joints are arranged there the temperature variations are highest to avoid uncontrolled shrink marks, which will break out where it is short diagonal distances. Now the shrink marks will follow the joints 32. The combustion chamber plate 30 is being provided with lice 31 over the joints 32. The louse 31 is to twist stabilize the element, due to the stove "moves" in relation to the temperature.

Figure 7 shows a perspective view of an afterburner 50 of the stove of Figure 2. The afterburner 50 consists of two supply pipes 51, with splitter with a flange (not shown) and a gasket crib 52. The afterburner 50 includes further a tubular afterburner boom 53, which is fixed to two reduction ducts (not shown), with lock flanges (not shown). The reduction ducts (not shown) are detachably fixed to the supply pipes 51. This makes the afterburner 50 dismountable. The lock flange (not shown) is a interleaving so that the afterburner not can be assembled wrong. The afterburner boom 53 has circular generally holes at the underside 54 and at the front side 55. These holes 54 and 55 supply secondary draft to the combustion system. Secondary air is supplied through the main duct 2, which is controlled by the damper 4, and via the air ducts 3 and 22, to the supply pipes 51. As the air passes through the air ducts 22 of the fill element 20, and over to the afterburner 50, with rectangular pipes 51, causes a large reduction of the air flowing through. This results in that the air is heated longer in the supply pipes 51 to the afterburner 50, of the heat of radiation from the fire, before the air reaches the splitter (not shown). The air then will be sucked to the sides and goes over to a further reduction duct (not shown). This results in that the gas, which is not burnt entirely at the fire, will be set on fire as it passes the hot air coming from the afterburner 50. The air supply at the underside 54 of the afterburner boom 53 will first set fire on the gas and increase the temperature further, and then it will continue up to the front side 55 and the gas also will be set on fire there. This results in that the gas, which is not entirely burnt at the fire, will be burned.

The afterburner 50 is as mentioned demountable, so that it can be changed if necessary. The purpose of this is to facilitate the cleaning of the stove, and to facilitate the changing of burning plates 71 and elements of the afterburner 50.

Figure 8 shows a grate 60, seen upside down, of Figure 2. The grate is placed over the outward draft collar 41 and ash bucket holder 40. The grate 60 is formed of four tubular ducts 61, which are welded together to a rectangular frame. The frame has, at the long sides, three horizontally directed holes 62, at the side of the grate 60 which facing inwards, which are adjusted to each other. These holes 62 provides for air supply from the ash bucket slits 42. To these holes there are welded three

pipes 63, with three vertical holes 64 at the underside. It is through these holes 64, the firing up draft (primary draft), which is controlled by the damper 4, is supplied. In addition, a gasket 62 is arranged at the bottom of the ducts 61, which creates the grate 60.

During firing, the coal, which falls down into the ash bucket, will be postponed to a draft from the grate 60, which will result in even more heat release.

When the fire is completely burned out, and it lays coal on the grate 60 and in the ash bucket, the damper 4 can be opened. This will result in an _^ increased flow through the main duct 2 to the grate 60, and a maximal combustion of the coal by that all air passes through the grate 60. This result in that only white ash powder is remaining and the grate 60 being empty for coal. This results in that the ash bucket does not need to be emptied so often.

Figure 9 shows details of the combustion chamber. The Figure shows burning plates 71, burning plate locks 72 and vault plate 73 for the stove of Figure 2. The vault plate 73 is arranged over the afterburner 50. Between the vault plate 73 and the convection plate 101, a tempering vault is created. Due to its location, the vault plate 73 provides the function of increasing the temperature of the air supplied to the afterburner 50, and it leads the smoke, gas and heat over the generally holes 54 and 55 of the afterburner 50. The burning plates 71 are to protect the stoves outer elements and reduce the temperature around the combustion chamber, due to the efficiency of the combustion chamber. The burning plate locks 72 "locks" all the burning plates 71 located above the vault plate 73. Figure 10 shows a second fill element 81 for the combustion chamber for the stove of Figure 2. It has a lower edge to receive sand which is placed around the grate 60. The sand will provide less load to the felt of Silcawool and to the bottom of the combustion chamber.

Figure 11 shows a door element 91 for a combustion chamber. These are used to adjust the height of the combustion chamber to the door which is being used. All the elements are like. Of this type of element, in the example are used two, which are arranged above of each other.

The duct system will now be described.

Figure 12 shows a convection plate" 101 for the stove of Figure 2. The convection plate 101 is located above the tempering vault, i.e. above the combustion chamber, and forms the change between the combustion chamber and the duct system. The Figure has arrows indicating the direction of the draft and smoke. The convection plate 101 includes a smoke collecting duct 102, a convection duct 103, a front slit 104, two concealed joints, and two lice 107. The front slit 104 extends to the convection duct 103. From the slit 104, cold air is supplied to the convection duct, which is heated by the smoke ducts lying around the convection duct.

The smoke collecting duct 102 has a recess at the back wall 105. At the air suck, at the right and left side of the duct, the recess 105 at the back wall will result in less contact with the smoke whirl at each side. At the back wall of the smoke collecting duct, burning plates 71 are arranged. The

recess 105 also provides an air gap between the burning plate and the convection plate 101, something which result in less load to the firewall. The air gap also provides for the burning plates 71 to expand in relation to the moisture content of the combustion material. The recess 105 is also made so that a soot brush, which has the same width, will be located at the correct place during sweeping of the smoke collecting duct 102. .

The concealed joints 106 are arranged at the back edge of the convection plate 101, inclined against the smoke collecting duct 102 ₄ The concealed joints 106, which not are generally, are filled with clay and does not extend all the way to the smoke collecting duct 102, due to sweeping tools not shall drag along clay from the concealed joints 106, and with that make them weaker. The concealed joints 106 are milled out after the moulding, due to moulding of the entire plate 101 results in a more solid plate. The concealed joints 106 are provided with lice 107 above the joints 106. The concealed joints are provided to observe shrink marks, while the lice 107 are used to twist stabilize the element.

Figure 13 shows a lower element 110 for direction of smoke for the stove of Figure 2. The lower element 110 for direction of smoke includes a smoke collecting duct 111 , a convection duct 112, two smoke switchers 113, two concealed joints 117 and two lice 118, and burning plates 71. The Figure has arrows indicating the direction of draft and smoke. The smoke collecting duct 111, convection duct 112, smoke switchers 113, concealed joints 117, lice 118, and burning plates 71 are arranged in the same way as for the convection plate 101. The smoke switchers 113 consist of a middle 114 and forward 115 ducts. The underside of the lower element 110 for direction of smoke is arranged against the convection plate 101.

The smoke switchers 113 have a circular opening 116, between the forward 115 and the middle 114 duct. This is to "turn" the smoke in the smoke switchers 113. Figure 14 shows an element 120 for continuing ducts for the stove of Figure 2. The stove can include several elements 120 for continuing ducts. The Figure has arrows indicating the direction of draft and smoke. The elements 120 for continuing ducts are arranged between the elements for direction of smoke, 110 and 130 (desδribed under Figure 15). The number of elements 120 for continuing ducts will depend of how high the stove should be. The minimum embodiment of the stove needs no such elements 120, but the elements for direction of smoke, 110 and 130 (described under Figure 15), are instead arranged above each other. The element 130 for continuing ducts is then lying upside down in relation to what is shown in Figure 15. The element 120 for continuing ducts includes smoke ducts 121, with a circular cross-section, a smoke collecting duct 122, a convection duct 123, two concealed joints, two lice 125, and burning plates 71. The smoke collecting duct 122, convection duct 123, concealed joints, lice 125, and burning plates 71 are arranged in the same way as for the convection plate 101. By the smoke ducts 121 having a circular cross-section, obtained is a stable draft and little soot is created. The smoke ducts 121 having a

circular cross-section also facilitate the cleaning of them, as you can cover everywhere. The smoke collecting duct 122, the speed of the smoke is in any case so high and the heat so high, that the creation of soot is minimal and thus they not need to be circular.

Figure 15 shows an upper element 130 for direction of smoke for the stove of Figure 2. The Figure has arrows indicating the direction of draft and smoke. The element 130 is arranged second from the top of the stove. The element 130 for direction of smoke includes a smoke collecting duct 131, middle smoke ducts 132, forward smoke ducts 133, a convection duct 134 and passages 135 between the smoke collecting duct 131 and the middle smoke duct 132, and two concealed joints 136, two lice 137, and burning plates 71. The smoke collecting duct 131, convection duct 134, concealed joints 136, lice 137, and burning plates 71 are arranged in the same way as for the convection plate 101. The element 130 for direction of smoke, switches the smoke from the smoke collecting duct 131 and to the middle smoke duct 132, by means of the passages 135.

The Figure 16 shows a smoke collar plate 140, with soot hatches 141 for the stove of Figure 2. The Figure has arrows indicating the direction of smoke. The smoke collar plate 140 includes soot hatches 140 with soot hatch recesses 142 at both sides, and forward smoke ducts, and a convection duct 144. The smoke collar plate is arranged at the top of the smoke switch 130. The smoke collars 140 function is to seal the top of the smoke collecting duct 131 and the middle smoke duct 132, so that the switch can be performed at the smoke switch element 130.

Figure 17 shows a smoke collar element 150 for the stove of Figure 2. The Figure has arrows indicating the direction of smoke. The smoke collar element 150 is formed by to opposite parts, which in addition forms the smoke pipe recess 151 and a soot hatch 152. The two opposite parts are held together by lice 153 of stainless steel threads. Figure 17 also shows a convection pipe 154 and two soot hatches 155, which are arranged at the top of the smoke collar plate 140. The smoke collar element 150 pulls out the heat from the mandrel/stem, and heats up the last part of the convection duct el, e2, e3, e4, e5 by means of the convection pipe 154, and collects the smoke and pulls out the last heat from it, before it is directed out in the chimney. The smoke collar element has a larger volume than the smoke duct, something which reduces the draft from the stove and, results in less particle emission into the chimney and provides better heat pull out from the smoke.

Figure 18 shows a top plate element 160 for the stove of Figure 2. The top plate 160 includes three soot hatches 161, 162, 163, and an outlet 164 for the convection duct. The soot hatch 161 is for sweeping of the smoke pipe leading to the chimney, while the soot hatches 162 and 163 are for sweeping the forward and respectively the middle smoke duct of the stove.

Again the reference is made to Figure 2, to describe how the duct system is working to obtain the advantages by the stove. The smoke that arise in the combustion chamber is introductorily directed in a upwards movement through the smoke collecting duct, which is formed by the generally holes al, a2, a3, and a4, of respectively the convection plate 101, lower element 110 for direction of

smoke, elements 120 for continuing ducts, and the upper element 130 for direction of smoke. To provide draft limiting and smoke collection, the smoke collecting duct al, a2, a3, and a4 has an oval cross-section. As smoke reaches the upper element 130 for direction of smoke, the smoke is directed in a downwards direction by that it is directed from the smoke collecting duct al, a2, a3, and a4 and over to the middle smoke ducts, which are formed of the generally holes bl, b2 and b3 of respectively the upper element 130 for direction of smoke, elements 120 for continuing ducts, and the lower element 110 for direction of smoke. As the smoke reaches the lower element 110 for direction of smoke, the smoke is directed to a upwards movement by that it is directed from the middle smoke duct to the forward duct, which is formed of the generally holes cl, c2, c3 and c4 of respectively the lower element 110 for direction of smoke, elements 120 for continuing ducts, and the upper element 130 for direction of smoke and the smoke collar plate 140. As the smoke reaches the smoke collar element 150, the smoke is collected and directed out in the chimney. In that way, a maximum utilization of the heat of the smoke, by that it is directed as long way as possible, before it is directed out in the chimney. The convection duct is formed of the generally holes el, e2, e3 ₅ e4, and e5 of respectively the convection plate 101, lower element 110 for direction of smoke, elements 120 for continuing ducts, upper element 130 for direction of smoke, and the smoke collar plate 140, and the convection pipe 154 and the outlet of the convection duct 164. The air in the convection duct el, e2, e3, e4, and e5 and the convection pipe 154, will be heated by the smoke in the smoke ducts bl, b2 and b3/cl, c2, c3 and c4, and of the smoke in the smoke collar element 150.

The convection duct el, e2, e3, e4 and e5, which starts over the convection plate 101, is supplied with cold air through a slit 104, arranged at the front side of the convection plate 101, which by that it is located above the fire, which results in that the supplied cold air does not reduce the combustion temperature at the fire, is something that provides a maximum combustion of the fire. In addition to the air flow through the convection duct el, e2, e3, e4 and e5, and the convection pipe 154, will pull out the heat from the mandrel/stem of the stove and direct it out in the room through the outlet of the convection duct 154*. The heat is created by the smoke which is directed through the smoke ducts bl, b2 and b3/cl, c2, c3 and c4. The convection duct provides for that the inner heat is more rapid directed out in the room, as the heated cold air will be pulled up in the convection duct. The stove has a standard door (not shown), where draft is supplied through a damper at the upper side of the door. This is so-called primary draft and is used when lightening the fire and for air flushing the glass. The air flushing prevents soot form adhering to the glass. When the combustion chamber plates have been heated, the damper above the door can be closed to the minimum, and then the draft which is regulated by means of the damper 4 be enough, as earlier described under Figure 3.

After the stove has been temperate, the user self can se if he/she is firing correctly by watching the afterburner 50 and adjust the damper 4. By balanced use of primary and secondary draft, which is regulated by the damper 4, it will burn over the entire afterburner boom 53. At unbalanced draft, it will only burn at the sides or at the middle of the afterburner boom 53. Use of balanced draft will result in energy saving and less pollution by maximum combustion.

By this design, a very simple assembling of the stove is obtained, and at the same time maximum combustion is obtained, by that no necessary cold air is affecting the fire, and by that the afterburner 50 which provides for that all gas is being burned, and a very favourable utilization of the heat through the smoke ducts bl, b2, b3/cl, c2, c3, which have a maximum length, and the convection duct el, e2, e3, e4 and e5, which provides a maximum heat surface by an inner and outer heat surface.

The build elements are put together of different types fractions of olivine and aluminous cement. Olivine has the quality that it stores and leads more heat than other types of stone, and three times as much as bricks. It also has the quality that it stands high temperatures without cracking. The elements are first moulded as one element, and the concealed joints 106, 107, 124, 136 / joints 32 are milled out afterwards, to provide elements as compact as possible, and minimum with horizontal joints which results in that puncture horizontally arises, and curetting of the joints with a soot brush.

The concealed joints 106, 117, 124, 136 are arranged so that they do not are located right above each other, to avoid to create a weak point in the construction.

The stove can have different assembling of build elements, something which for example is shown by Figures IA and IB, but still have the same advantageous features as described.

Another advantageous feature is that, if it sloppy work is done of the maintenance, i.e. sweeping, you can by feel it at the stoves forward ducts at the right and left side. If a possible soot plug arises, one of the sides will be warmer than the other. In this way you can discover this early and avoid the stove being damaged.

In front of the stove it must be a sl'a'b of slate or similar, to protect the floor against, for example, live coal.