FR2876177A1 - Solid fuel e.g. sawdust, distributor for stove, has fixed cylinder with rotary axle delimiting fuel distribution areas in which blades are distributed, where blades of one area are shifted with respect to blades of adjacent area - Google Patents

Abstract

The distributor has a fixed cylinder with longitudinal upper supply and lower distribution openings. A rotary axle (6) mounted inside the cylinder supports walls (7) transversal to the axle and delimits fuel distribution areas (8). The axle has a cylinder pierced with off-centered openings. Blades (9) are distributed in areas, where the blades of one area are shifted with respect to the blades of the adjacent area. An independent claim is also included for a stove.

Description

Distributor for solid fuel stove and stove equipped with such

distributor.

  The present invention relates to the field of design and construction of stoves.

  The invention is particularly but not exclusively applicable in the context of the manufacture of fuel stoves consisting of granules of wood derivatives, such as sawdust.

  Such a fuel, commonly referred to by those skilled in the art under the Anglican pellet s, has the advantage of being environmentally friendly while allowing very high combustion yields. It also has a heating value (Pci) of the order of 5000 Wh / kg. This type of fuel is made from untreated and selected clean sawdust. These sawdust are crushed, dried and finally agglomerated without glue. The granules thus obtained are cooled and dusted before being stored in bulk or packaged in bags.

  These granules generally have a size of 6 mm for domestic applications and a size of 8 mm in diameter for industrial applications.

  Such granules are a cheap fuel but have the disadvantage of burning with difficulty due to their great compactness.

  Therefore, the stoves used to burn them must include dynamic ventilation means, such as a turbine, to bring to it the amount of oxidant required.

  In this type of stoves specially designed for the combustion of pellets, they are fed from a tank by a worm to the stove hearth said hearth being ventilated by the dynamic ventilation means mentioned in the previous paragraph. However, such stoves do not always make it possible to obtain good combustion.

  This type of stoves of the state of the art also has the disadvantage of not having means preventing a return of fuel combustion to the tank. However, such a return of combustion can be harmful to the device and involve a danger for the users of it or the people present in the room where it is located.

  Moreover, stoves of the state of the art specially designed for the combustion of wood pellets do not always allow a continuous and regular distribution of these pellets in the home.

  Although the invention finds particular application in the context of wood pellet stoves, the present invention may also be implemented for other types of stoves operating with other fuels such as including conventional wood logs, densified logs or wood chips.

  The object of the present invention is to provide means to overcome the disadvantages of the stoves of the state of the art and mainly those designed for the combustion of wood pellets.

  In particular, an object of the present invention is to provide such means that ensure a regular distribution of fuel in the stove.

  Also, an object of the present invention is to describe such means which make it possible to proscribe a combustion return to the tank containing the fuel.

  Yet another object of the present invention is to describe such means allowing the fuel to be delivered into the hearth of the stove according to variable delivery speeds.

  Yet another object of the present invention is to provide such means to overcome the use of turbine or other dynamic ventilation means to allow the perfect combustion of the fuel.

  These various objectives are achieved by the invention which relates to a device for feeding a solid fuel stove for delivering said fuel into the hearth of said stove characterized in that it comprises at least one fixed cylinder provided with a longitudinal upper feed opening and a lower longitudinal distribution opening and inside which an axis is rotatably mounted, said rotary shaft supporting at least three walls substantially transverse to said axis and defining at least two fuel distribution sectors, means for rotating said rotary axis, and means for successively discharging by gravity all or part of the contents of said sectors in the stove hearth by said lower longitudinal distribution opening.

  According to a variant of the invention, said means for successively discharging by gravity all or part of the contents of said sectors in the focus include a plurality of blades substantially parallel to said axis, said blades of a sector being offset with respect to the blades of another sector.

  This type of feed device is a fuel dispenser that can be used in the context of the realization of any type of stove. As already indicated, however, it finds particularly but not exclusively its application for the distribution of wood pellets.

  Such a device may allow the fuel to be distributed in the stove hearth on a regular basis, in particular when the means for rotating the axis supporting the transverse walls and the vanes impose a regular rotational speed on the device.

  During this rotation, the fuel is delivered into the stove hearth alternately a compartment of a sector, then a compartment of the neighboring sector. Thus, the delivery of the fuel into the stove hearth is substantially continuous and essentially regular and allows the fuel to preheat and ignite over a width sufficient to give the appearance of a real wood fire It will be noted that, preferentially, the fuel distribution sectors of the feed device according to the present invention will have essentially the same size.

  As indicated above, the feed device according to the present invention must have a number of transverse walls delimiting at least two fuel distribution sectors. However, according to a preferred variant of the invention, this device will have five transverse walls defining four solid fuel distribution sectors. It will be noted that the more the number of sectors of the device will be high, the more fuel distribution in the fireplace of the stove equipped with such a device can be fluid and regular.

  It should also be noted that the number of blades planned in each distribution sector may vary. However, according to a preferred variant, each solid fuel distribution sector is provided with four vanes equidistributed around said axis of rotation. For each sector, each blade thus forms with each of the two adjacent vanes an angle substantially of 90 delimiting compartments of sizes. equal.

  Also according to a preferred variant of the invention, the blades of each sector will be offset by an angle α relative to the vanes of the adjacent sector, a being equal to 360 / N / n, where N is the number of sectors of the device and n being the number of blades per sector.

  Thus, when according to the preferred embodiment of the invention, the device will integrate four sectors each having four blades, the angle alpha will be 360/4/4 or 22.5.

  It will also be noted that preferably the device according to the invention will include means making it possible to vary the speed of rotation of its rotary axis, so as to allow the delivery of a greater or lesser amount of fuel into the stove. The higher the speed of rotation of the rotary axis, the higher the frequency of distribution of fuel from the compartments of the sectors, and therefore the amount of fuel delivered into the fireplace of the stove can be significant.

  According to another variant of the invention, said means for successively discharging by gravity all or part of the contents of said sectors in the home include a rotary cylinder delimiting said sectors and having as many openings as sectors, said openings being offset.

  The invention also relates to any stove having a hearth stove body 30, at least one combustion hearth of said fuel, means for supplying air to said hearth and at least one solid fuel tank characterized in that it is equipped with at least one solid fuel supply device as described above, connected to said reservoir and at least one chute connecting said device inside said home.

  Preferably, the stove according to the present invention has at least one duct which communicates in its lower part with an orifice located near the chute and which opens into the upper part of the stove. Such a duct advantageously allows cooling said chute by passage of convection air.

  Also preferably, the hearth is constituted by a crucible pierced with orifices in its side walls and or in its bottom wall.

  The use of such a crucible and / or of such a conduit makes it possible to inject the air necessary for the combustion of the fuel in a sufficient quantity to allow the perfect combustion of the fuel distributed in the hearth of the stove without using any means of combustion. dynamic ventilation such as a turbine. The manufacture of the stove is facilitated and its cost price is reduced.

  The invention, as well as the various advantages that it presents, will be more easily understood thanks to the following description of a nonlimiting embodiment thereof, given with reference to the drawings in which: FIG. a sectional view of a stove equipped with a fuel supply device according to the present invention; Figure 2 shows a perspective view of this feeder; FIG. 3 represents a view from above of this same device; Figure 4 shows the rotary axis of the feeder shown in Figures 2 and 3; Figure 5 schematically shows the offset of the blades of the different sectors of the feed device according to the present invention; FIG. 6 represents a perspective view of the crucible equipping the stove according to FIG. 1; Figure 7 shows an alternative embodiment of a portion of the dispenser device according to the invention.

  Referring to Figure 1, a stove for the combustion of wood pellets (pellets) is shown in cross section.

  This stove comprises three main parts, namely a stove body 13 delimiting a fireplace 2, a fuel tank 11 and a distributor 1 of this fuel in the fireplace 2 of the stove.

  In a conventional manner, this stove body 13 is equipped with a hearth 10, a first door 16 giving access to the interior of the hearth 2, a second door 17 giving access to the hearth 10, a slot 18 allowing the supply of secondary air necessary for afterburner, a deflector 19 and flue gas discharge means 20 including a control flap.

  The fuel is stored in the tank 11 and distributed through the distributor 1 in the firebox 2 of the stove and more precisely on the sole 10 thereof, via a chute 12.

  According to the present invention, the sole 10 is integrated in a crucible 14 having on its side walls orifices 15. This crucible 14 is shown in more detail in FIG.

  A primary air inlet nozzle 22, equipped with a control flap for regulating the amount of air entering the stove, is provided in the lower part thereof near the crucible 14.

  Furthermore, the body of the stove 13 is equipped with a double wall defining a conduit 21 which communicates in its lower part with a hole 21a located near the chute and which opens into the upper part of the stove. This duct 21 allows the passage of convection air and allows the chute 12 to be cooled. The stove according to the present invention therefore does not have dynamic ventilation means such as a turbine, usually necessary to obtain a correct combustion of the fuels. difficult combustion such as wood pellets. Indeed, the invention makes it possible to dispense with such dynamic ventilation means which have the disadvantage of being expensive and of making the manufacture of stoves more complex in favor of static ventilation means constituted essentially by the duct 21 and the integration the sole 10 in a crucible 14 pierced with orifices on its side walls 15 which cooperates synergistically with the dispensing system 1 which will now be described below in more detail with reference to FIGS. 1, 2, 3, 4 and 5.

  With reference to FIG. 1, the fuel distribution device comprises a cylinder 3 inside which is mounted a rotary shaft 6 which cooperates with conventional means for rotating this axis of rotation 6, which means can be motorized (These means are not shown in the figures).

  The cylinder 3 has an upper longitudinal opening 4 which cooperates with the reservoir 11 and through which the fuel pellets contained in the tank 11 fall by gravity into the distributor 1. This cylinder 3 also has a lower longitudinal opening 5 allowing the distribution of the fuel pellets to the stove hearth. To this end, this longitudinal opening 5 of the cylinder 3 cooperates with a chute 12, also longitudinal, which opens into the lower part of the stove 2, above the sole 10, so as to allow the distribution by gravity of fuel granules on this one.

  Referring to Figure 3, which shows a top view of the granule dispensing device according to the present invention, and with reference to Figure 4 which shows a part of this device, it will be noted that it comprises in addition to the cylinder 3 and the rotary axis 6, five walls 7 transverse to the axis of rotation 6.

  These transverse walls 7 of circular shape cooperate with the cylinder 3 and have for this purpose a diameter just smaller than that of this cylinder. These transverse walls 7 delimit four distribution sectors 8 of equal size.

  Furthermore, the distributor 1 comprises sixteen blades 9 distributed at the rate of four blades per sector 8. These blades 9 are fixed on the one hand to the rotary axis 6 and on the other hand to the transverse walls 7 and delimit four compartments 8a of equal sizes by sector 8.

  According to the present invention, the blades 9 of a sector 8 are offset relative to the blades 9 of the adjacent sector 8.

  With reference to FIG. 5, it will be noted that the sectors 8 taken from left to right in FIG. 4 have blades 0, 90, 180, 2700 for the first sector; for the second blade sector at 22.5, 112.5, 202, 5, 292.5; for the third blade sector at 45, 135, 225 and 315, and finally for the fourth blade sector at 67.5, 157.5, 247, 5 and 337.5.

  Such an arrangement corresponds to a shift of 22.5 between the blades 9 of one sector with respect to the adjacent sector.

  Such an arrangement of the blades 9 in the sectors 8 makes it possible to deliver the fuel into the chute 12 compartment of one sector per compartment of the adjacent sector, on a regular basis.

  The distribution of the pellets in the hearth 2 of the stove is thus almost linear. The regular fuel supply of the stove makes it possible to obtain a perfect combustion of it in the firebox 2.

  FIG. 7 represents an alternative embodiment of the rotary shaft represented in FIG. 4.

  According to this variant, this axis 6 is equipped with a cylinder 6a which is also rotatable and which is pierced with offset orifices 23. Walls 7 disposed at the ends and inside the cylinder 6a delimit sectors 8 of equal sizes. (For the sake of clarity in Figure 7, only an inner wall 7 is shown.

  The offset openings 23 in the cylinder allow the distribution of the fuel over a wide width while avoiding the return of combustion to the tank.

  Note that the stove described in this embodiment may include means for varying the speed of the rotation means of the axis of rotation 6. In this way, it will be possible to adjust the feed speed of the stove in fuel and thus to obtain a higher or lower heating temperature.

  The embodiment of the invention described here is not intended to reduce the scope thereof. In particular, many modifications may be made within the scope of the claims without departing from its scope. In particular, it should be noted that the number of sectors will be at least two but may be three, four or more than four. Similarly, the number of blades per sector may be different from four without departing from the scope of the invention.

Claims (12)

  1. Device for feeding (1) a solid fuel stove for delivering said fuel into the hearth of said stove characterized in that it comprises at least one fixed cylinder (3) provided with an upper longitudinal opening of supply (4) and a lower longitudinal opening of distribution (5) and within which an axis (6) is rotatably mounted, said rotary axis (6) supporting at least three walls (7) substantially transverse to said axis ( 6) and delimiting at least two distribution sectors (8) of fuel, means for rotating said rotary axis, and means for successively discharging by gravity all or part of the contents of said sectors in the hearth of the stove through said opening lower longitudinal distribution.   2. Device according to claim 1 characterized in that said means for successively discharging by gravity all or part of the contents of said sectors in the home include a rotary cylinder delimiting said sectors and having as many openings as sectors, said openings being offset .   3. Device according to claim 1 characterized in that said means for successively discharging by gravity all or part of the contents of said sectors in the focus include a plurality of vanes (9) substantially parallel to said axis (6), said blades (9). ) of one sector being offset from the vanes of another sector.   4. Device according to one of claims 1 to 3 characterized in that said fuel distribution sectors (8) have substantially the same size.   5. Device according to one of claims 1 to 4 characterized in that it has five transverse walls (7) defining four sectors of distribution (8) of solid fuel.   6. Device according to any one of claims 3 to 5 characterized in that each solid fuel distribution sector (8) is provided with four blades (9) equidistributed around said rotary axis (6).   7. Device according to any one of claims 3 to 6 characterized in that the blades (9) of each sector (8) are offset by 360 / N / n, relative to the blades (9) of the sector (8) adjacent Where N is the number of sectors of the device and n is the number of blades per sector.   8. Device according to claims 5, 6 and 7 characterized in that the blades (9) of each sector (8) are offset by 22.5 relative to the blades of the adjacent sector.   9. Device according to any one of claims 1 to 8 characterized in that it comprises means for varying the rotational speed of said rotary axis.   10. Stove having a stove body (13) forming a hearth (2), at least one combustion hearth (10) of said fuel, means for supplying air to said hearth (10) and at least one tank (11) solid fuel characterized in that it is equipped with at least one solid fuel supply device (1) according to any one of claims 1 to 9 connected to said reservoir and at least one chute ( 12) connecting said device to said interior.   11. Stove according to claim 10 characterized in that it has at least one conduit (21) which communicates in its lower part with an orifice (21a) located near the neck and which opens into the upper part of the stove.   12. Stove according to any one of claims 10 or 11 characterized in that said sole (10) is integrated in a crucible (14) pierced with orifices (15) in its side walls and or in its lower wall.