WO2008059300A1

WO2008059300A1 - Fireplace with gravitational feeding for pellet

Info

Publication number: WO2008059300A1
Application number: PCT/HU2007/000108
Authority: WO
Inventors: Sarolta Fülöp; István Magas; József Simkó; Ferenc CSERJÉS; József STURM; Gábor DIENES
Original assignee: Fireplace Kft.
Priority date: 2006-11-16
Filing date: 2007-11-15
Publication date: 2008-05-22
Also published as: HUP0600848A2; HU0600848D0

Abstract

The fireplace with gravitational feeding for pellets is made with possibility of pellets feeding placed in the bottom of the fireplace into the firebox in such way that the continuous combustion in the firebox is provided. The fireplace (1) comprises the pellet holder (2) with hd (4) placed in the upper part of the fireplace (1) and the pellet material is forwarded gravitationally in a slanted pellet channel (7) from the pellet holder (2) into the firebox (9), and said slanted pellet channel (7) ends in the firebox and is provided with the closing valve (8). In the bottom of the firebox (9) there is grate (34) of bent bars of round cross-section. The feeding of primary air takes place through primary air nozzle (21) with help of primary draft regulator (22) in such a way, that the primary air flows through the primary air nozzle (24) among the bars of the grate (34) into the burning pellet mateπal. The secondary air is led through the secondary air intake (25) and the secondary draft regulator (26) to the heatproof glass (28) of the firebox door (27) of the firebox door above the firebox door. The tertiary air intake (16) is found on the back of the fireplace (1) from where the tertiary air flows into the smouldeπng pellet material situated in the pellet burning space (2) through the tertiary duct (33) and tertiary air nozzles (19). The fireplace comprises is a flame deflector (29), a flue detector (30), the heat exchangers (13) in the upper part of firebox (9). In the upper part of the fireplace the flur stamp is placed.

Description

Fireplace with gravitational feeding for pellet

The subject of the invention is fireplace with gravitational feeding for pellet, the arrangement of which makes it possible, that the pellet fuel placed in the fireplace can get to the firebox in such a way, that it continuously ensures the combustion in the firebox.

Among various forms of fireplaces the fireplaces working with pellet fuel have been spreading more and more. Pellet made from natural materials, residues of plants, wood offers environmental-friendly solution on the one hand, on the other hand its use is very easy and practical. In case of fireplaces the use of pellets is even more advantageous, because by the help of this the continuous feeding of the fuel can be solved in a simpler way than in case of woodburning fireplaces.

The HU 222 130 Hungarian patent description in the state of the art makes known a fireplace insert for forming the firebox for fireplaces, respectively tilestoves or built-in fireplaces. The fireplace insert according to the invention is of trapezoid shape consisting of a firebox, bordered by slanting sidewalls and a combustion gas duct formed above the firebox. The fireplace insert is provided with a grate in the lower part of firebox for feeding primary air, as well as a firebox mantle bordering the firebox from outside and a heatproof firebox insert enveloping the firebox inside. In the front of the firebox there is a transparent firebox door made of heatproof material, on the ash dump placed below the grate, there is a primary air intake, that can be regulated, above the firebox door a secondary air intake led to the upper part of the firebox door is formed.

The characteristic of the fireplace insert described here is, that at approximately the half height of the firebox, in the sidewalls and/or backwall of the firebox there are tercier air intakes, preferably evenly sectioned out, furthermore in the sidewalls and/or backwall of the firebox in the upper third of the height there are afterburner air intakes preferably evenly sectioned out.

Above the firebox there is a combustion gas duct formed from a flame deflector placed below and a flue deflector placed above it approximately parallel, overlapping each other in such a way, that the opening between the flame deflector and the backwall of the firebox provides for the expel of combustion gases from the firebox.

A solution for a solid fuel burning heating stove of trapezoid cross-section is described in the EP 496 043 patent description. Here the intake of secondary air takes place according to the abovementioned solution, and the feeding of tercier air occurs through the openings formed at half height of the backwall of the firebox. The heating stove has a sinkable underlay, where a grate can be found. When the fuel is placed on the underlay, the underlay moves downwards and meanwhile it moves a closing lid, which opens an air feeding opening placed under the grate towards the downward movement of the underlay. The EP 530 126 European patent description makes known a fireplace-stove formation provided with closed firebox and with a glass insert part. The glass insert part is placed on the front of the fireplace-stove, preferably in the door. The fireplace-stove has a built- in heat exchanger, which consists of a closed chamber, to which the air is fed through an opening. The air inlet opening is placed on the upper part of the glass part. The secondary air flowing in here creates an air mantle, extending along the back wall of the glass part. The firebox is formed in such a way, that it consists of a closed box, placed on the inner side of the front of the stove, abo.ve the glass part, and in which the feeding of air into the secondary air duct is regulated by the openings at the front of the stove.

The GB 562256 English patent description makes known a firebox operating with external air feeding. The firebox includes a grate on legs and a forked rake, which can be moved on a handle. The external air flows below the grate, then goes further through the grate, from below towards the upper part, to the firebox.

The drawbacks of the known solutions are:

The up-to-date modern pellet-burning stoves are provided with expensive electronic controls, feeders with electric motor with wormgear, fans with combustion gas exhausts in order to maintain the combustion continually, to feed the pellet in the right time and right quantity and to control the chimney draught, so they are very expensive and resulting from the complicated electronic equipment and mechanics they are bound to break down more often.

When working out the solution according to the invention we aimed to make a fireplace with simple structure, and with low production cost, which can ensure continuous operation of pelletburning fireplaces without human intervention with a simple solution.

When working out the solution according to the invention we realized, that production of an cost-effective pelletstove conforming with the market requirements can be achieved by using gravitation for moving the pellet fuel. Therefore in case the storing and feeding of pellet into the firebox is solved in such a way, that the pellet fuel slides down continuously from the pellet holder to the firebox through a slanted channel resulting from gravity, then the set aim can be achieved.

The invention is a fireplace with gravitational feeding for pellet, said fireplace has a firebox provided with primary, secondary and tertiary and afterburner air intakes, furthermore said fireplace has air intakes on the sides and internal burning air distributing system, as well as the primary air intake of the fireplace is placed in the grate in the bottom of the firebox, the secondary air intake is placed above the firebox door, and the tertiary air intakes are formed in the back wall of the firebox.

The fireplace according to the invention is characterized by that, the fireplace has a pellet holder with lid placed in the upper part of the fireplace and the pellet material is forwarded gravitationally in a slanted pellet channel from the pellet holder into the firebox, and there is a closing valve in the slanted pellet channel, and the slanted pellet channel ends in the firebox, in the bottom of the firebox there is a grate of bent bars of round cross-section,

feeding of primary air takes place through primary air intake with the help of primary draft regulator in such a way, that the primary air flows through the primary air nozzle among the bars of the grate into the burning pellet material, and the secondary air is led through the secondary air intake and the secondary draft regulator to the heatproof glass of the firebox door above the firebox door, furthermore the tertiary air intake is found on the back of the fireplace, from where the tertiary air flows into the smouldering pellet material situated in the pellet burning space through the tertiary duct and tertiary air nozzles, furthermore there is a flame deflector, a flue deflector, as well as heat exchangers in the upper part of the firebox, and in the upper part of the fireplace the flue stump is placed.

In one of preferred embodiment of the fireplace according to the invention the α angle of the slanted pellet channel is 40°-60°, preferably 45°.

In another preferred embodiment of the fireplace according to the invention the lid of holder can be opened with the help of a closing lever by a hinge and the closing of the lid of holder is ensured by sealing.

In a further preferred embodiment of the fireplace according to the invention the fireplace has a convection ventilator at the bottom of the fireplace to supply heat, and said convection ventilator delivers hot air through a convection air-duct and the convection air channel as well as through the heat exchanger, hot air openings and covering grid to the space to be heated.

In a further preferred embodiment of the fireplace according to the invention the firebox is bordered by combustion space mantle.

In a further preferred embodiment of the fireplace according to the invention the pellet burning space is surrounded from three sides by tertiary ducts from where the tertiary air feeding burning flows through tertiary air nozzles.

The solution according to the invention is furthermore set forth with the enclosed drawings:

The Fig 1 shows a possible realization of the solution according to the invention in the lengthwise section of the fireplace.

The Fig 2 shows the arrangement according to Fig 1 in A-A section of Fig 1.

The Fig 3 shows the arrangement of the fireplace according to the invention in front view of Fig 1.

The Fig 1 shows a possible realization of the solution according to the invention in the lengthwise section of the fireplace. The pellet holder 2 of the fireplace 1 can be seen in the picture. The pellet material is placed into the holder after having opened the lid 4 of the holder. The lid 4 of the holder can be opened with the help of closing lever 3 of holder through the hinge 5. The proper closing of the lid 4 of the holder is ensured with the help of sealing 6. The pellet material is gravitationally forwarded from the pellet holder 2 into the slanted pellet channel 7. The a angle of the slanted pellet channel 7 is 40°-60°, preferably 45°. The closing valve 8 is situated in the slanted pellet channel 7. The slanted pellet channel 7 ends in the firebox 9, where the grate 34 consisting of bent bars of round cross-section can be found. The ash falls down through the gaps of the grate 34 to the ash pan 32 situated at the bottom of the fireplace 1.

The tertiary air intake 16 can be found in the back of the fireplace 1. The tertiary air flows from here into the smouldering pellet material situated in the pellet burning space 20 through the tertiary duct 33, and the tertiary air nozzles 19 formed on the tertiary air stump 18. The air feeding of the smouldering pellet material takes place with the help of primary air through the primary air intake 21 with the help of the primary draft regulator 22. The primary air flows into the burning pellet material through the primary air nozzle 24 through the bars of the grate 34.The flame deflector 29, the flue deflector 30 as well as the heat exchangers tubes 13 can be found in the firebox 9. The flue stump 31 is located on the upper part of the fireplace.

In order to increase the efficiency of the heat output of the fireplace 1 the heat produced in the firebox 9 is led into the heat exchanger 13 with the help of a convection ventilator 10 through the flexible convection air-duct 11 and convection air channel 12 where it is heated and through the warm air exhaust openings and through the covering grid 15 it is flown into the space to be heated. In the front of the fireplace 1 the door 27 with heatproof glass 28 can be found. In order to avoid, that the heatproof glass 28 get sooted, the secondary air is led to the heatproof glass 28 of the door 27 through the secondary air intake 25 and secondary draft regulator 26.

The Fig 2 shows the arrangement according to Fig 1 in A-A section of Fig 1. The fireplace 1 with the firebox 9 as well as the pellet burning space 20 can be seen in the picture. The firebox 9 is bordered by the combustion space mantle 35. The joint of the throat 17 to the pellet burning space 20 of the slanted pellet channel 7 with the grate 34 and primary air nozzle 24 below can be seen in the picture. The tertiary ducts 33 surrounding the pellet burning space 20 along three sides can be well seen in the picture ensuring the stream of tertiary air feeding the burning through tertiary air nozzles 19. The firebox door 27 with heatproof glass 28 can be seen in the picture, as well as the ventilator 10 at the bottom of the fireplace 1.

The Fig 3 shows the arrangement of the fireplace according to the invention in front view of Fig 1. The firebox door 27 with heatproof glass 28 of the fireplace 1 can be seen in the picture, as well as the primary draft regulator 22. The closing lever of pellet channel 36 as well as the covering grid 15 and the closing lever 3 of the pellet holder can be seen in the picture.

The main units of a preferable concrete realization of the fireplace with gravitational pellet feeding according to the invention are:

- Pellet holder 2 with gasproof welding, safe sealing, with sealed lid 4 along the rim, - Slanted pellet channel 7 for the pellet, feeding burning, slanted in the proper angle conforming with the gravitational moving of the pellet, starting from the pellet holder 2, ending at the burner, with a closing valve 8 placed inside, which can prevent the movement of the pellet and can be tilted,

- Pellet-burner, which is the pellet burning space 20, slanted in conformity with the movement of the gravitational moving of the pellet, with a grate at the end helping burnt pellet pieces to peel and to keep back the pellet pieces still burning, as well as back and side tertiary air nozzles 19,

- Primary air nozzle 24, which directs air only to the area of burning flame, ensuring this way efficient combustion,

- Firebox 9 similar to a traditional fireplace and firebox door 27 with heatproof glass 28, but amended so, that it is provided with a primary draft regulator 22 of increased cross- section to ensure draw of bigger quantity primary air necessary for pellet-burning,

- Heat exchanger 13 with tubes, which can be provided with convection ventilator 10 to achieve better heat output,

- Ash pan 32

Operation of the fireplace with gravitational pellet feeding according to the invention is as follows:

The lid of the pellet holder is opened, the fireplace is filled with pellet, then the lid is closed. During filling the closing valve is in closed position, then after the filling the valve is opened and the pellet is slowly let down into the burner. The fire is lit with the help of a fire-lighting cube while the draft regulators are open.

The pellet is sliding down in the slanted channel from the pellet holder in a proper angle, ensuring steady ungraded supply for the pellet burner. At the bottom of the pellet burner there is a grate of bent bars of round cross-section, which keeps back the movement of the pellet, so the fire is permanently burning above the grate. The burnt pellet becomes smaller, so it can fall through the proper size gaps of the grate. This way it gives way to the downward movement of the behind it pre-heated, ignited pellet particles. This movement develops into a process during the time of burning. The speed of burning depends of the degree of draft, so the output of the fireplace can be adjusted ungraded.

Draft intake to the burning space can be found on several places. The air gets to the primary air nozzles through the primary draft regulating opening of suitable size placed at the bottom of the firebox door, and the ash pan. It ensures, that the air is directed to the flame only, promoting efficient burning. On the back wall and side walls of the burner there are tertiary air nozzles, here there is no regulation, conforming with the formed draft, the quantity of air necessary for burning is coming through. On the upper part of the firebox door there is a secondary air regulator built in, though this air does not play an important part in burning, only it keeps clean the heatproof glass by flowing down behind the glass. In case of manual pellet feeding from bags, if the pellet channel closing valve is open, then the pellet can pour in very quickly above the grates of the burner into the firebox, overfilling the burning space.

The possibility of closing of the pellet channel ensures prevention of overfilling of the pellet in the course of filling of new pellet portion, as well as the possibility of turning off the fire. After having closed the pellet channel, pellet feeding stops, the pellets below the closing valve finish burning, but in lack of supply the fire dies out.

Heat transfer takes place through the transparent firebox door glass, through the convection openings on the sides, and below the top of the fireplace, as well as through the air flowing through the heat exchanger tubes, hi order to increase heat output the quantity of air flowing through the heat exchanger tubes can be increased by a convection ventilator.

The advantages of the solution according to the invention are:

The up-to-date modern pellet-burning stoves are provided with expensive electronic controls to ensure pellet feeding in the proper time and quantity, feeders with electric motor with wormgear, to control flue draft ventilators with combustion gas exhausts.

The fireplace with pellet feeding offers a more cost-effective production of a fireplace meeting with the market demands with realizing moving of the pellets by the force of gravity.

Claims

CLAIMS:

1. Fireplace with gravitational feeding for pellet, said fireplace has a firebox provided with primary, secondary and tertiary and afterburner air intakes, furthermore said fireplace has air intakes on the sides and internal burning air distributing system, as well as the primary air intake of the fireplace is placed in the grate in the bottom of the firebox, the secondary air intake is placed above the firebox door, and the tertiary air intakes are formed in the back wall of the firebox, characterized by that, the fireplace (1) has a pellet holder (2) with lid (4) placed in the upper part of the fireplace (1) and the pellet material is forwarded gravitationally in a slanted pellet channel (7) from the pellet holder (2) into the firebox (9), and there is a closing valve (8) in the slanted pellet channel (7), and the slanted pellet channel (7) ends in the firebox (9), in the bottom of the firebox (9) there is a grate (34) of bent bars of round cross-section,

feeding of primary air takes place through primary air intake (21) with the help of primary draft regulator (22) in such a way, that the primary air flows through the primary air nozzle (24) among the bars of the grate (34) into the burning pellet material, and the secondary air is led through the secondary air intake (25) and the secondary draft regulator (26) to the heatproof glass (28) of the firebox door (27) above the firebox door (27), furthermore the tertiary air intake (16) is found on the back of the fireplace (1), from where the tertiary air flows into the smouldering pellet material situated in the pellet burning space (20) through the tertiary duct (33) and tertiary air nozzles (19), furthermore there is a flame deflector (29), a flue deflector (30), as well as heat exchangers (13) in the upper part of the firebox (9), and in the upper part of the fireplace (1) the flue stump (31) is placed.

2. Fireplace according to claim 1, characterized by that, the angle (α ) of the slanted pellet channel (7) is 40°-60°, preferably 45°.

3. Fireplace according to claim 1 or 2 characterized by that, the lid of holder(4) can be opened with the help of a closing lever (3) by a hinge (5) and the closing of the lid of holder (4) is ensured by sealing (6).

4. Fireplace according to any of claims 1 to 3 characterized by that, the fireplace (1) has a convection ventilator (10) at the bottom of the fireplace (1) to supply heat, and said convection ventilator (10) delivers hot air through a convection air-duct (11) and the convection air channel (12) as well as through the heat exchanger (13), hot air openings and covering grid (15) to the space to be heated.

5. Fireplace according to any of claims 1 to 4 characterized by that, the firebox (9) is bordered by combustion space mantle (35).

6. Fireplace according to any of claims 1 to 5 characterized by that, the pellet burning space (20) is surrounded from three sides by tertiary ducts (33) from where the tertiary air feeding burning flows through tertiary air nozzles (19).