JP5097674B2 - Combustion equipment - Google Patents

Description

  The present invention relates to a combustion apparatus, in particular, a biomass combustion apparatus, and more particularly to suppression of clinker generation.

  Various combustion apparatuses have been proposed in order to obtain heat and to dispose of unnecessary materials. In such a combustion apparatus, various techniques for burning solid fuel (particularly often biomass fuel) formed in pellets or chips have been proposed. In the combustion of the solid fuel formed in such a pellet shape or chip shape, it has been required to solve the difficulty of reliably burning the solid fuel.

As a combustion apparatus that performs combustion of such solid fuel, a technique that includes an inner cylinder and an outer cylinder and performs primary combustion and secondary combustion has been proposed (for example, see Patent Document 1).
The combustion apparatus of Patent Document 1 includes a nozzle having a double structure of an outer cylinder and an inner cylinder, a nozzle connected to the opening of the cylinder, a supply path for supplying solid fuel to the inner space of the inner cylinder, It is equipped with an internal space of the inner cylinder and a ventilation port for supplying air to the internal space of the nozzle. First, solid fuel is supplied to the inner cylinder to perform primary combustion, and then gas and residue generated by the primary combustion move to the nozzle. Secondary combustion is performed at the nozzle. Furthermore, combustion efficiency is raised because the cylinder can be rotated.
US Pat. No. 6,164,220

However, the prior art has the following problems.
(1) The combustion apparatus of Patent Document 1 is provided with a large number of outlets for taking air into an inner cylinder serving as a primary combustion chamber, and a large amount of air is supplied to the primary combustion chamber. For this reason, it burns very vigorously in the inner space of the inner cylinder, which is the primary combustion chamber, and the combustion temperature reaches 1000 ° C. In such a case, there is a problem that ash melts during temporary combustion and a large amount of clinker is generated. For this reason, in the primary combustion, it is necessary to suppress the combustion temperature and make the combustion temperature in the secondary combustion higher than the combustion temperature in the primary combustion.

(2) The combustion apparatus needs to burn pellet-like or chip-like solid fuel. This is because when the combustion apparatus burns biomass fuel, the biomass fuel is solidified into pellets or chips. In order to solve the problem (1), if the combustion temperature in the primary combustion is lowered, the solid fuel in the form of pellets or chips increases in the amount of unburned fuel and remains in the inner space of the inner cylinder as it is. Sometimes it remains. There is a problem in that a large amount of clinker is also generated by smoldering such unburned residue in primary combustion.
When a large amount of clinker is generated, the clinker adheres to and accumulates on the inner wall of the inner cylinder, and adversely affects combustion. For example, the clinker blocks the air outlet that supplies air to the internal space of the inner cylinder. In order to remove the adverse effect on combustion, it is necessary to remove the attached clinker, which hinders continuous operation of the combustion apparatus.

  (3) Moreover, if the primary combustion and the secondary combustion are explicitly formed in different spaces or members, there is a problem that the combustion apparatus becomes large. In order to avoid such an increase in size, it is necessary to form the primary combustion and the secondary combustion with an integral member, and a device for that is required.

  The present invention solves such problems, and provides a combustion apparatus that can reduce the generation of clinker as much as possible, and can burn solid fuel efficiently while being small in size.

In view of the above problems, the combustion apparatus of the present invention is
1) A cylinder having a front end that is an opening and a rear end that is a closing part, and having a double structure of an outer cylinder and an inner cylinder that are rotatable on the same axis, and an outer side of the cylinder at the opening. A nozzle connected to a cylinder, a ventilation port formed in the closed portion, for supplying air to the internal space of the nozzle via a gap between the inner cylinder and the outer cylinder, and the ventilation path A blowout port for blowing a part of the flowing air into the inner space of the inner cylinder, a supply path connected to the closed portion and communicated with the inner space of the inner cylinder, and supplying solid fuel to the inner space of the inner cylinder; A blower for supplying air to the ventilation port, and a rotation driving means for rotating the cylinder, wherein the cylinder has an inclination with the nozzle facing upward with respect to a horizontal plane, and is provided outside at the opening. The opening area between the cylinder and the inner cylinder is equal to or larger than the opening area of the outlet, and the inner area of the inner cylinder A pulverizing member for pulverizing the solid fuel is accommodated in a partial space, the inner cylinder includes a plurality of pipe frames along a rotation axis direction, the pipe frame communicates with the ventilation path, Combustion device 2 formed on the inner space side of the inner cylinder in the pipe frame ) The air supplied to the inner space of the inner cylinder is 30% to 50% of the total amount of air supplied from the ventilation port, The combustion apparatus 3) according to 1), wherein the air supplied to the internal space of the nozzle is 50% to 70% of the total amount of air supplied from the ventilation port. The pulverizing member is a ceramic ball. 4) The combustion apparatus according to 3), wherein the ceramic ball is a substantially spherical body mainly composed of alumina oxide and having a particle diameter of 2 to 30 mm.
5) The combustion apparatus according to any one of 1) to 4), wherein the solid fuel is a biomass fuel.
It is.

  The combustion apparatus of the present invention supplies air to both the internal space of the inner cylinder and the internal space of the nozzle while rotating the cylinder. Further, the supply path supplies pellet-like or chip-like solid fuel (for example, biomass fuel) to the inner space of the inner cylinder, and the solid fuel is finely pulverized by collision with a pulverizing member formed of a ceramic ball or the like. .

  Since the solid fuel is finely pulverized in the inner space of the inner cylinder, the fuel in the primary combustion in the inner cylinder is a very small solid. Since the primary combustion burns at a lower temperature than the secondary combustion and generates gas, the fuel to be combusted is a very small solid, so that less residue can be generated. Naturally, it is difficult for heavy burnout to occur. As a result, most of the gas and residue float on the nozzle that performs secondary combustion. In particular, since the fuel is decomposed into fine solids, the volatile components contained in the fuel are easily pyrolyzed, gasification is performed quickly, and the time required for complete combustion can be shortened. In addition, since the inner cylinder and the nozzle are upward with respect to the horizontal plane, the pulverizing member does not jump out even if the cylinder rotates.

  In addition, since a majority of the air supplied from the ventilation port is supplied to the nozzle that performs secondary combustion, the combustion temperature at the nozzle increases, and the fuel that has become gas or residue is exposed to high-temperature combustion at the nozzle. The resulting ash is quickly discharged. As a result, the clinker is not easily generated, and the clinker is not attached to the inner cylinder or the nozzle, and the combustion apparatus can be stably operated continuously. Furthermore, since the primary combustion and the secondary combustion can be configured as an integrated device, the combustion device can be downsized.

A combustion apparatus according to a first aspect of the present invention has a front end that is an opening and a rear end that is a closing portion, and has a double structure of an outer cylinder and an inner cylinder that can rotate coaxially. And a nozzle connected to the outer cylinder of the cylindrical body at the opening, and air is supplied to the inner space of the nozzle through the gap between the inner cylinder and the outer cylinder formed as an air passage. A vent opening that blows a part of the air flowing through the ventilation path into the inner space of the inner cylinder, and is connected to the inner space of the inner cylinder connected to the closed portion, and is solid in the inner space of the inner cylinder. A supply path for supplying fuel; a blower for supplying air to the ventilation opening; and a rotation driving means for rotating the cylinder, wherein the cylinder is inclined with a nozzle facing upward with respect to a horizontal plane The opening area between the outer cylinder and the inner cylinder in the opening is the opening area of the outlet An upper, housing a grinding member for crushing the solid fuel to the interior space of the inner cylinder, the inner cylinder is provided with a plurality of pipe frames along the rotation axis direction, the pipe frame is the air passage communicating with And the said blower outlet is formed in the internal space side of the inner cylinder in the said pipe frame.
With this configuration, first, pellet-like or chip-like solid fuel (for example, biomass fuel) supplied to the inner space of the inner cylinder that performs primary combustion is finely pulverized by the pulverizing member in the inner space of the inner cylinder. When the solid fuel is finely pulverized, volatile components contained in the fuel are easily pyrolyzed, gasification is rapidly performed, and unburned residue and residue are hardly generated. Further, since the nozzle faces upward with respect to the horizontal plane, the pulverizing member does not jump out of the cylindrical body. The ventilation port supplies a majority of the taken-in air to the nozzle that performs the secondary combustion, so the combustion temperature at the nozzle is higher than the combustion temperature at the inner cylinder. As a result, the nozzle burns the gas and residue floating from the inner cylinder at a high temperature to perform complete combustion, and quickly discharges the generated ash. As a result, the generation of clinker is suppressed, the occurrence of malfunctions in the combustion apparatus is suppressed, and the internal cleaning cycle can be lengthened to realize a stable continuous operation of the combustion apparatus. As described above, by combining the constituent requirements according to the first invention, it is possible to solve all the problems of the conventional combustion apparatus, to reliably burn the fuel, and to provide a stable continuous operation combustion apparatus. Can be provided.
Furthermore, this configuration facilitates the formation of the inner cylinder.

In the combustion apparatus according to the second aspect of the present invention, in addition to the first aspect, the air supplied to the internal space of the inner cylinder is 30% to 50% of the total amount of air supplied from the ventilation port. The air supplied to the internal space of the nozzle is 50% to 70% of the total amount of air supplied from the ventilation port.
With this configuration, the combustion temperature in the inner space of the nozzle is higher than the combustion temperature in the inner space of the inner cylinder. That is, primary combustion for gasifying the pulverized solid fuel is performed in the inner space of the inner cylinder, and secondary combustion for burning and ashing the gas and residue floating from the inner cylinder is performed in the inner space of the nozzle.

In the combustion apparatus according to the third aspect of the present invention, in addition to the first or second aspect, the pulverizing member is a ceramic ball.
With this configuration, the solid fuel supplied to the inner space of the inner cylinder is easily pulverized.

In the combustion apparatus according to the fourth aspect of the present invention, in addition to the third aspect, the ceramic balls are substantially spherical bodies mainly composed of alumina oxide and having a particle diameter of 2 to 30 mm.
With this configuration, a pulverizing member that easily pulverizes solid fuel can be realized. Further, since the pulverized member becomes flame retardant, it is easy to use.

In the combustion apparatus according to the fifth aspect of the present invention, in addition to any one of the first to fourth aspects, the solid fuel is a biomass fuel.
With this configuration, the combustion apparatus can also be applied as a biomass combustion apparatus.

First, the general outline of the present invention will be described.
The combustion apparatus of the present invention is a combustion apparatus that mainly burns solid fuel, and obtains heat by burning pellet-like or chip-like solid fuel (for example, biomass fuel). The combustion device generally includes a primary combustion part (inner cylinder) that gasifies solid fuel and a secondary combustion part (nozzle) that burns and ashes the gas. And a small device that completely burns fuel by secondary combustion.

  A combustion apparatus of the present invention has a front end that is an opening and a rear end that is a closing portion, and has a cylindrical structure having a double structure of an outer cylinder and an inner cylinder that can rotate coaxially, and a cylinder at the opening. A nozzle connected to an outer cylinder of the body, a ventilation port formed in the closing portion, and supplying air to the internal space of the nozzle via a gap between the inner cylinder and the outer cylinder as an air passage; A blowout port that blows out part of the air flowing through the ventilation path to the inner space of the inner cylinder, and a supply path that is connected to the closed portion and communicates with the inner space of the inner cylinder and supplies solid fuel to the inner space of the inner cylinder And a blower for supplying air to the ventilation opening, and a rotation drive means for rotating the cylinder, wherein the cylinder has an inclination with a nozzle facing upward with respect to a horizontal plane, and the opening The opening area between the outer cylinder and the inner cylinder in the part is not less than the opening area of the outlet, Accommodating a grinding element for grinding the solid fuel in the internal space of the tube.

  First, pellet-like or chip-like solid fuel is supplied from the supply path to the inner space of the inner cylinder. The inner cylinder is a cylinder located inside the outer cylinder in the cylinder, and houses a pulverizing member made of a small-diameter ceramic ball or the like. The inner cylinder can be rotated together with the outer cylinder and the nozzle, and the solid fuel supplied to the inner space of the inner cylinder is repeatedly pulverized with the crushing member in accordance with the rotation of the inner cylinder. Here, since the nozzle of the cylinder is inclined upward with respect to the horizontal plane, the crushing member stored in the internal space of the inner cylinder does not pop out even when the cylinder is rotated.

  The solid fuel in the inner cylinder is ignited and starts to burn. At this time, since the solid fuel is finely pulverized by the pulverizing member, the volatile components contained in the fuel are easily pyrolyzed, and gasification is rapidly performed. In addition, the finely pulverized residue hardly causes residue and unburned residue, and most of the solid fuel supplied to the inner cylinder is gasified by combustion in the inner cylinder, and the gas is discharged together with the residue inevitably generated by air retention. To float.

  The opening area between the outer cylinder and the inner cylinder in the opening is equal to or larger than the opening area of the air outlet, and the amount of air supplied to the internal space of the nozzle out of the amount of air taken in from the vent is It is more than the amount of air supplied to the internal space. For this reason, the combustion temperature in the nozzle is higher than the combustion temperature in the inner cylinder. That is, the nozzle plays a role of secondary combustion that burns at a high temperature. The gas and residue floating on the nozzle are burned at high temperature and ashed. Because there is little residue and unburned residue, it is completely burned and clinker is rarely generated. Since it is surely incinerated, the ash is quickly discharged from the nozzle.

  As described above, in the combustion apparatus of the present invention, the solid fuel is surely completely burned so that the clinker is hardly generated. This is because the combustion apparatus of the present invention is (1) a rotatable inner cylinder and outer cylinder, (2) the nozzle of the cylinder is upward with respect to the horizontal plane, and (3) the pulverizing member is housed inside the inner cylinder (4) The primary combustion is performed in the inner cylinder and the secondary combustion is performed in the nozzle. (5) The amount of air supplied to the nozzle is greater than or equal to the amount of air supplied to the inner cylinder. It is realized by being.

  Here, (5) In order for the amount of air supplied to the nozzle to be greater than or equal to the amount of air supplied to the inner cylinder, for example, the inner cylinder includes a plurality of pipe frames along the rotation axis direction. The air passage is in communication with the air outlet, and the air outlet is formed on the inner space side of the inner cylinder of the pipe frame. Further, based on this structure, the air supplied to the inner space of the inner cylinder is 30% to 50% of the total amount of air supplied from the ventilation port, and the air supplied to the inner space of the nozzle is the ventilation port. By controlling so that it may become 50%-70% of the total air amount supplied from, the balance of primary combustion and secondary combustion becomes optimal, and it becomes difficult to produce a clinker.

  Further, when the pulverizing member is a ceramic ball having a substantially spherical body mainly composed of alumina oxide and having a particle diameter of 2 to 30 mm, the solid fuel supplied to the inner space of the inner cylinder while maintaining flame retardancy Can be easily crushed.

As described above, the combustion apparatus of the present invention can suppress the generation of clinker even when solid fuel is burned, prevent the occurrence of problems in combustion, and realize a stable continuous operation.
Note that not only solid fuel but also liquid or gaseous fuel may be supplied to the combustion device. Moreover, a combustion apparatus may be specifically called a biomass combustion apparatus by supplying biomass fuel to a combustion apparatus.
Examples will be described below.

  1-3 is an example in which the combustion apparatus of the present invention is applied to combustion of biomass fuel. FIG. 1 is a cross-sectional view of the biomass combustion apparatus of the embodiment, FIG. 2 is a cross-sectional view of the cylindrical body of the embodiment, and FIG. 3 is an explanatory view showing a use state of the biomass combustion apparatus of the embodiment. In the figure, 1 is a cylindrical body, 2 is an outer cylinder, 3 is an inner cylinder, 4 is a tubular body, 5 is a nozzle, 6 is a fireproof layer, 7 is a ventilation path, 8 is a ventilation opening, 9 is a pipe frame, 10 is a blower Outlet, 11 is a support, 12 is a bearing, 13 is a motor (rotation drive means), 14 is a blower, 15 is an air supply path, 16 is a supply path, 17 is a screw conveyor, 18 is a motor, and A is biomass fuel ( Solid fuel) and B are ceramic balls (crushed members).

  As shown in FIGS. 1 and 2, an elongated tube body 4 is attached to the rear end of a double-structured cylinder body 1 having an outer cylinder 2 and an inner cylinder 3 having a front end that is an opening and a rear end that is a closing portion. The nozzle 5 having the refractory layer 6 on the inner surface is connected to the outer cylinder 2, and the ventilation for the air to blow through the gap between the outer cylinder 2 and the inner cylinder 3 and blow it out to the nozzle 5. A ventilation port 8 for taking air into the ventilation path 7 is formed at the rear end of the outer cylinder 2, and six pipe frames 9 are provided in the axial direction on the wall surface of the inner cylinder 3 to communicate with the ventilation path 7. Four small diameter air outlets 10 are formed in the inner cylinder 3 space side of the pipe frame 9 at four locations.

  A motor 13 that rotates the cylindrical body 1 by tilting the cylindrical body 1 at 15 degrees so that the nozzle 5 faces upward and rotatably supporting the cylindrical body 1 on the support body 11 via a bearing 12 at the position of the tubular body 4 is provided. An air blower 14 that is provided on the support 11 and takes in outside air is attached to the support 11, and an air supply path 15 that sends the taken-in air to the air vent 8 and the bearing 12 is provided on the support 11.

  The end port of the supply path 16 of the biomass fuel A is slidably brought into contact with the rear end port of the tube body 4, and the screw conveyor 17 is disposed in communication with the tube body 4 and the supply channel 16. A motor 18 that rotates on the supply path 16 side is provided, and a large number of ceramic balls B that pulverize the biomass fuel A are accommodated in the inner cylinder 3. The ceramic ball B is mainly composed of alumina oxide and is formed in a granular shape having an outer diameter of 4 to 8 mm.

  As shown in FIG. 3, when the blower 14 and the motors 13 and 18 are operated, the cylindrical body 1 and the screw conveyor 17 rotate independently, and the outside air sucked by the blower 14 is supplied to the air supply path 15, the ventilation port 8, and the ventilation. The air is sent to the nozzle 5 through the passage 7, and a part of the air in the ventilation passage 7 is blown into the inner space of the inner cylinder 3 through the pipe frame 9 and the air outlet 10. The opening area between the outer cylinder 2 and the inner cylinder 3 is equal to or larger than the opening area of the air outlet 10, and the ratio of the amount of air supplied to the inner space of the inner cylinder 3 is 40% of the total amount of air. The ratio of the amount of air supplied to the internal space is 60% of the total amount of air.

  When the biomass fuel A is heated to a temperature equal to or higher than the ignition point temperature by a heating means (not shown) and is supplied through the supply path 16, it is transferred by the screw conveyor 17 and sent to the inner cylinder 3. Collide with, pulverize and fluidize. Since the ceramic ball B is heavier than the biomass fuel A and the cylinder 1 is inclined backward, it does not roll in the direction of the nozzle 5.

  The pulverized biomass fuel A is partially combusted with the air supplied from the outlet 10, and the generated heat raises the temperature in the inner cylinder 3 to 200 to 600 ° C., and the volatile component contained in the biomass fuel A Is pyrolyzed and gasified. Since the biomass fuel A is pulverized by the ceramic balls B, the volatile components are easily pyrolyzed and gasification is performed quickly. However, since the amount of supplied air is not large, the inner space of the inner cylinder 3 is maintained in a low oxygen state, and the biomass fuel A does not burn vigorously by raising the flame.

  The gas and residue float to the nozzle 5, mix with air supplied in large quantities through the ventilation path 7, and completely burn, and the combustion gas and ash are discharged directly from the nozzle 5. Although the internal space of the nozzle 5 becomes a high temperature of about 1200 ° C., the ash is quickly discharged from the nozzle 5 before melting, and the clinker is hardly generated. Further, although the heat of combustion tries to be transmitted to the bearing 12, since the outside air taken in by the blower 14 is also supplied to the bearing 12 through the air supply path 15, the bearing 12 is always cooled and seizes even if it is operated for a long time. There is nothing.

  The combustion apparatus of the present invention is used for power generation, boilers, and the like.

It is sectional drawing of the biomass combustion apparatus of an Example. It is sectional drawing of the cylinder of an Example. It is explanatory drawing which shows the use condition of the biomass combustion apparatus of an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylindrical body 2 Outer cylinder 3 Inner cylinder 4 Pipe body 5 Nozzle 6 Fireproof layer 7 Ventilation path 8 Ventilation opening 9 Pipe frame 10 Air outlet 11 Support body 12 Bearing 13 Motor (rotation drive means)
14 Blower 15 Air supply path 16 Supply path 17 Screw conveyor 18 Motor A Biomass fuel (solid fuel)
B Ceramic ball (crushed material)

Claims (5)

A cylindrical body having a front end that is an opening and a rear end that is a closing portion, and having a double structure of an outer cylinder and an inner cylinder that are rotatable coaxially;
A nozzle connected to the outer cylinder of the cylindrical body at the opening;
A vent hole that is formed in the closed portion and supplies air to the internal space of the nozzle via a gap between the inner cylinder and the outer cylinder as a ventilation path;
A blowout port for blowing a part of the air flowing through the ventilation path into the inner space of the inner cylinder;
Connected to the closed portion and communicated with the inner space of the inner cylinder, and a supply path for supplying solid fuel to the inner space of the inner cylinder;
A blower for supplying air to the ventilation opening;
Rotation driving means for rotating the cylinder,
The cylindrical body has an inclination with the nozzle facing upward with respect to a horizontal plane,
The opening area between the outer cylinder and the inner cylinder in the opening is not less than the opening area of the outlet.
Storing a pulverizing member for pulverizing the solid fuel in the internal space of the inner cylinder ;
The inner cylinder includes a plurality of pipe frames along a rotation axis direction, the pipe frame communicates with the ventilation path, and the air outlet is formed on the inner space side of the inner cylinder in the pipe frame. apparatus.   The air supplied to the internal space of the inner cylinder is 30% to 50% of the total amount of air supplied from the ventilation port, and the air supplied to the internal space of the nozzle is supplied from the ventilation port. The combustion apparatus according to claim 1, wherein the combustion apparatus is 50% to 70% of the total air amount.   The combustion apparatus according to claim 1, wherein the pulverizing member is a ceramic ball.   The combustion apparatus according to claim 3, wherein the ceramic ball is a substantially spherical body mainly composed of alumina oxide and having a particle diameter of 2 to 30 mm. The combustion apparatus according to any one of claims 1 to 4 , wherein the solid fuel is a biomass fuel.

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