JP5037900B2 - Vertical firing furnace - Google Patents

Description

  The present invention is for heating and firing granular limestone, dolomite, magnesite, iron ore, or granulated raw material (hereinafter referred to as “raw material”) at high temperature using a granular solid fuel. The present invention relates to a vertical firing furnace.

  As this type of vertical firing furnace, the vertical firing furnace disclosed in Patent Document 1 is known. In this known firing furnace, an annular plate-like rotary hearth that rotates around a vertical axis is provided below the furnace lid, and the raw material is supplied from the outside through a raw material supply pipe for supplying the raw material to be fired. A primary deposition layer of the raw material is formed by dropping into the preheating space. The primary deposition layer forms an upper free surface on the raw material supply pipe side and a lower free surface facing the combustion chamber with an angle of repose. A burner for burning gas or liquid fuel is provided at the center position of the furnace lid, and combustion gas is generated in the combustion chamber. Radiation heat transfer from high-temperature flame and combustion gas in the combustion chamber to the lower free surface of the primary deposition layer facing the combustion chamber formed in the central space portion of the rotary hearth directly under the furnace lid, and the primary deposition layer The raw material is heated by convective heat transfer from the combustion gas flowing through the upper portion and flowing out to the upper free surface to achieve firing (semi-firing) of about 50 to 60%. By the action of a plurality of pushers arranged around the furnace, the semi-fired raw material is dropped from the dropping port formed in the central part of the rotary hearth, and is provided so as to continuously extend downward to the hearth. A secondary deposition layer of the above-mentioned semi-fired raw material is formed in the lower space of the cylindrical furnace main body, and complete firing is performed here.

  In this patent document 1, in addition to the gas or liquid fuel injected from the burner provided in the center of the furnace lid, as a fuel, solid fuel can be supplementarily used as needed. Is provided with a solid fuel supply port. The solid fuel supply port is provided at an eccentric position away from the center of the furnace lid, and when the solid fuel falls into the rotating furnace body, a part of the primary deposition layer is generated along with the rotation of the furnace body. Most of the water is uniformly supplied in the circumferential direction on the surface of the secondary deposition layer in the furnace body.

In the furnace body where the secondary deposition layer is formed, a part of the combustion gas in the combustion chamber is sucked into the secondary deposition layer from the free surface above the secondary deposition layer and flows downward. Therefore, this secondary deposited layer is completely fired by the above-mentioned combustion gas flowing into the product. The product is dropped and taken out from the outlet at the bottom of the furnace body. At this time, the product is cooled by the air flowing into the furnace body from the outlet and the air flowing through the ejector.
Japanese Patent No. 3623016

  In such a firing furnace of Patent Document 1, gas or liquid fuel is used in order to perform combustion uniformly in the combustion chamber, resulting in a high fuel cost. Although the fuel cost can be suppressed by using the solid fuel as an auxiliary, it is only an auxiliary and since the main fuel is gas or liquid fuel, the fuel cost is not greatly reduced. In addition, the solid fuel supply port is in an eccentric position from the center of the furnace lid, and the solid fuel is supplied uniformly in the circumferential direction by the rotation of the furnace body. However, the surface of the secondary deposition layer becomes uneven for some reason. If this is the case, this cannot be corrected, and the solid fuel is deposited non-uniformly on the secondary deposition layer.

  Therefore, in the firing furnace of Patent Document 1, when solid fuel is used as the main fuel, the deposition on the secondary deposition layer tends to be more uneven. Furthermore, since the amount of solid fuel that reaches the surface of the primary deposition layer on the hearth is small, it is difficult to promote firing by combustion in the primary deposition layer. In addition, in Patent Document 1, when a solid fuel supply port is provided at this position instead of the burner located at the center of the furnace lid, the solid fuel to be supplied in a fall is a secondary deposition layer at the central position. Mountains are formed in the furnace, and the distribution in the furnace radial direction is not uniform.

  In view of such circumstances, the present invention uses an inexpensive solid fuel, distributes the solid fuel uniformly with a simple structure, and not only on the secondary deposition layer but also on the primary deposition layer. It is an object of the present invention to provide a vertical firing furnace that can be widely distributed and can be burned and fired efficiently and uniformly.

  The vertical firing furnace according to the present invention has an annular hearth that rotates around a vertical axis and has a material outlet formed in the center, and a furnace lid that is fixedly disposed above the hearth. An outer cylinder portion having an outer diameter larger than that of the dropping port and continuously provided on the furnace lid and an outer cylinder portion connected to the inner cylinder portion at an upper portion are provided around the furnace lid. The outer cylinder part is formed to extend downward longer than the inner cylinder part, and the furnace cover is provided with a fuel supply port for supplying solid fuel from the outside to a combustion chamber formed immediately below, An airtight sealing device is provided between the lower end of the outer cylinder part and allows relative rotation of the hearth with respect to the furnace lid. The inner cylinder part and the outer cylinder part connected at the upper part and the furnace An annular preheating space formed by being surrounded by a floor is provided with a raw material supply pipe for supplying the raw material to the preheating space from the outside. A furnace body in the form of a vertical cylinder is provided extending downward from the edge of the drop opening formed in the center of the hearth so as to communicate with the combustion chamber and communicate with the combustion chamber. The raw material in the space falls from the side facing the combustion chamber, and an outlet for taking out the raw material that has fallen from the dropping port and baked in the furnace main body as a product is formed in the lower part of the furnace main body. Is formed.

In such a vertical firing furnace, in the present invention, the fuel supply port is formed by a lower end opening of a fuel supply pipe that enters the furnace toward the combustion chamber at the center of the furnace lid, and the lower end opening of the fuel supply pipe has a furnace radius. The vertical axis passing through the center position of the furnace lid is opened by the driving device with the vertical axis passing through the center position of the furnace lid as a furnace axis . Further, the fuel supply pipe is combined with the solid fuel. While receiving air and supplying these from the lower end opening, a plurality of holes are formed in the peripheral wall of the fuel supply pipe, and air is blown out from the holes to the combustion chamber .

According to the present invention having such a configuration, the solid fuel is discharged from the lower end opening of the rotating fuel supply pipe toward the outside of the furnace in the radial direction of the furnace, and is supplied by being dropped. Therefore, in addition to being uniformly distributed in the circumferential direction, the solid fuel is also widely distributed in the radial direction. As a result, the solid fuel is applied to the primary deposition layer and the secondary deposition layer. Since such a solid fuel promotes the semi-firing of the raw material by combustion in the primary deposition layer, it enhances the firing in the secondary deposition layer and makes the firing in the secondary deposition layer uniform.
The fuel supply pipe receives air together with the solid fuel and supplies them from the lower end opening, and a plurality of holes are formed in the peripheral wall of the fuel supply pipe, and air is blown out from the holes to the combustion chamber. It is like that. By doing so, a large amount of air is blown out from the hole to the combustion chamber, and the remaining air is sent out together with the solid fuel from the lower end opening of the fuel supply pipe. The air that has come out of the hole stirs the combustion gas in the combustion chamber and the pulverized fuel that can be scattered with a small diameter among the solid fuel, and provides oxygen for the combustion, so that the combustion is performed well. . On the other hand, the air coming out from the lower end opening of the fuel supply pipe will send the solid fuel farther away due to its flow velocity.

  In the present invention, it is preferable that the lower end opening of the fuel supply pipe not only faces outward in the furnace radial direction, but the opening position is separated from the furnace axis in the furnace radial direction. By doing so, the solid fuel reaches further radially outward and is more widely distributed on the primary deposition layer.

  In the present invention, the furnace lid is provided with a plurality of air supply ports distributed in the circumferential direction at positions away from the furnace axis in the furnace radial direction, and combustion air is directed from the air supply ports to the combustion chamber. Can be blown. In order to spread the solid fuel from the lower end opening of the fuel supply pipe as far as possible in the radial direction in order to spread widely on the primary sedimentary layer, it will fall in the radial direction, especially near the center. There is a possibility of insufficient solid fuel. In that case, when combustion air is blown from the air supply port, not only oxygen for combustion is supplied, but also the solid fuel falling from the fuel supply pipe is dispersed by the flow velocity. As a result, the solid fuel is distributed near the center, and the distribution is kept uniform.

  The air supply port is preferably located outward in the furnace radial direction from the lower end opening of the fuel supply pipe and is directed inward in the furnace radial direction. By doing so, the solid fuel scattered outward in the furnace radial direction from the lower end opening of the fuel supply pipe is pushed back inward in the same direction, so that it is distributed widely and uniformly in the same direction.

  It is desirable that the hole is provided so as to open toward a space formed between the inner peripheral surface of the opening of the furnace lid that allows the fuel supply pipe to pass therethrough and the outer peripheral surface of the fuel supply pipe. This is because this space is a region where combustion is most actively performed in the combustion chamber and requires a lot of oxygen.

  In the present invention, the driving device is outside the furnace and can drive the outside part of the fuel supply pipe.

  As described above, when the solid fuel is dropped and supplied from the fuel supply pipe provided in the furnace lid of the vertical firing furnace, the present invention allows the fuel supply pipe to enter the furnace at the center position of the furnace lid and the lower end opening to the furnace. Since the fuel supply pipe is rotated outwardly in the radial direction with the vertical line passing through the center position of the furnace lid as the axis, the solid fuel dropped and supplied from the fuel supply pipe into the furnace is uniform in the circumferential direction. And it is distributed over a wide range extending outside the furnace radius. As a result, the solid fuel is distributed not only in the secondary deposition layer but also in the primary deposition layer, promoting the semi-firing of the raw material in the primary deposition layer, and thus increasing the degree of calcination in the subsequent secondary deposition layer. .

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

<First embodiment>
In FIG. 1, reference numeral 1 denotes a furnace lid made of a heat-resistant material. An inner cylinder portion 2 is continuously provided on the outer periphery of the furnace lid 1, and an outer cylinder portion 3 is provided outside the inner cylinder portion 2. ing. The furnace lid 1 is connected to the lower part of the inner cylinder part 2 by an inner connection part 4. The inner cylinder part 2 and the outer cylinder part 3 are connected to each other by an outer connection part 5 at an upper part thereof, and the outer cylinder part 3 extends below the inner cylinder part 2.

  An annular plate-like hearth 6 made of a heat-resistant material is rotatably provided below the furnace lid 1. The hearth 6 is rotated around a center line 7 as a vertical furnace axis passing through the center position of the furnace lid 1 and a furnace body 9 described later by an external driving device (not shown). In FIG. 1, the center line 7 is indicated by a one-dot chain line. Between the outer peripheral edge of the hearth 6 and the lower end of the outer cylinder part 3, a sealing device 8, for example, a well-known water seal is provided to seal between the two. Rotation of the hearth 6 is allowed while maintaining airtightness. A drop port 6A is formed at the center of the hearth 6 and a vertical cylindrical furnace body 9 is continuously provided downward from the periphery of the drop port 6A. In the case of the present embodiment, the furnace body 9 is shaped like a bottom toward the bottom. An air supply pipe 10 for supplying cooling air from the outside to the inside of the furnace is provided at a lower position inside the furnace body 9. The air supply pipe 10 enters a pipe from a bottom pipe 12 provided via a rotary joint 11 so as to allow rotation of the furnace main body 9 at a position near the lower end of the furnace main body 9 and opens upward. Is provided with an umbrella member 13 that prevents entry of the raw material in the furnace body 9. An outlet 14 for taking out the product is provided at the lower part of the bottom tube 12.

  A combustion chamber 15 is formed immediately below the furnace lid 1, and an annular preheating space 16 is formed by the inner cylinder portion 2, the outer cylinder portion 3, the outer connection portion 5 and the hearth 6 so as to surround the combustion chamber 15. The preheating space 16 is open toward the combustion chamber 15 within the radius. The preheating space 16 is provided with a rod-shaped pusher 16A extending in the radial direction from the outside so as to penetrate the outer cylinder portion 3, and appropriately reciprocate in the radial direction of the furnace (longitudinal direction of the rod). .

  In the upper position of the furnace lid 1, a raw material to be fired, for example, a pellet made by mixing and molding a mineral such as limestone, dolomite, magnesite or various inorganic substances is stored in advance. A device 17 is arranged. In the case of this embodiment, the storage device 17 has an upper storage device 17A and a lower storage device 17B, which are connected via a rotary valve 18 that is an airtight supply mechanism. In the case of this embodiment, the rotary valve 18 is divided into four chambers. The rotary valve 18 receives the raw material S from the upper storage device 17A in the chamber positioned above by the rotation of the rotary valve 18, and the rotary valve 18 is rotated. The raw material S is allowed to drop into the lower storage device 17B when the chamber is positioned downward along with the rotation of the upper storage device 17A. Receive the ingredients.

  In the outer connection portion 5 forming the upper wall of the preheating space 16, a plurality of raw material supply pipes 19 for supplying the raw material from the lower storage device 17 </ b> B into the preheating space 16, and exhaust gas from the upper portion of the preheating space 16. The exhaust gas conduit 20 to be led is connected.

  A fuel supply pipe 21 for supplying solid fuel into the furnace is provided at the center position of the furnace lid 1, and a plurality of air supplies for supplying combustion air into the furnace around the center position of the furnace lid 1. A tube 22 is provided. A cylindrical portion 23 is provided at the center of the furnace lid 1 so as to protrude toward the outside of the furnace. The fuel supply pipe 21 passes through the furnace lid 1 and the cylindrical portion 23, and is provided to be rotatable around the center line 7. Above the fuel supply pipe 21, a fuel input pipe 24 for supplying solid fuel to the fuel supply pipe 21 is provided. A bent chute 25 for injecting solid fuel into the fuel input tube 24 extends upward from the side of the fuel input tube 24. Above the chute 25, a screw conveyor 26 for conveying solid fuel from the outside is provided, and is connected to the upper end of the chute 25 via a rotary valve 26A. A drive device 27 provided outside the furnace is connected to a portion outside the furnace of the fuel supply tube 21, and the fuel supply tube 21 rotates around the center line 7 under the drive of the drive device 27.

  FIG. 2 is a diagram showing details of the configuration above the furnace lid 1. As described above, the fuel supply pipe 21 is provided at the center position of the furnace lid 1. A flange 21 </ b> A is provided on the outer peripheral surface of the fuel supply pipe 21 at the middle position in the longitudinal direction. While the fuel supply pipe 21 is rotatable around the center line 7, its own weight is supported by the flange portion 21 </ b> A of the fuel supply pipe 21 by a sealed thrust bearing 28 provided at the upper end of the cylindrical portion 23.

  The lower end side of the fuel supply pipe 21 enters the combustion chamber 15. The lower end side of the fuel supply pipe 21 is curved toward the fuel supply port 21B, which is the lower end opening, so that the gradient with respect to the horizontal plane becomes smaller, and the fuel supply port 21B opens outward in the furnace radial direction. ing. That is, the lower end opening 21B is located away from the center line 7 in the furnace radial direction. The upper end side of the fuel supply pipe 21 is formed so that the outer diameter thereof is larger than the outer diameter at the intermediate portion, and a radial bearing 29 with a seal is provided at the upper end opening. The lower end opening of the fuel input pipe 24 is inserted into the upper end opening of the fuel supply pipe 21, and the fuel input pipe 24 rotates the fuel supply pipe 21 in a radial direction via the sealed radial bearing 29. I support it.

  A sprocket 21C is attached to the outer peripheral surface on the upper end side of the fuel supply pipe 21, and a chain 30 indicated by a one-dot chain line in FIG. 2 is connected to the sprocket 21C and the sprocket 27A provided in the driving device 27. It is stretched. Thus, when the drive device 27 rotationally drives the sprocket 27A, the rotational driving force is transmitted to the sprocket 21C, and the fuel supply pipe 21 rotates around the center line 7 in the direction indicated by the arrow in FIG. In the furnace lid 1, a plurality of air supply pipes 22 are provided on a circumference around the center position around the position of the fuel supply pipe 21, that is, around the center position of the furnace lid 1. As shown in FIG. 2, the air supply pipe 22 is located outward in the furnace radial direction from the fuel supply port 21B of the fuel supply pipe 21, and is inward in the furnace radial direction, specifically in the direction of the fuel supply port 21B. It is suitable. The air supply pipe 22 is connected to an air supply device (not shown) and blows combustion air into the combustion chamber 15. Note that the timing of blowing combustion air may be set as appropriate. For example, the combustion air may be constantly blown or periodically blown.

  The solid fuel conveyed by the screw conveyor 26 falls to the chute 25 via the rotary valve 26A, and further reaches the fuel supply pipe 21 from the fuel input pipe 24. Here, the rotary valve 26A drops and supplies the solid fuel in the same manner as the rotary valve 18 described above. As described above, the fuel supply pipe 21 receives the driving force from the driving device 27 and rotates around the center line 7. In the rotated state, the fuel supply pipe 21 receives the solid fuel from the fuel input pipe 24 and puts the solid fuel into the furnace. Drop supply. Specifically, the solid fuel slides down the curved inner surface of the fuel supply pipe 21 and is discharged from the fuel supply port 21B. Since the fuel supply pipe 21 rotates and releases the solid fuel, the solid fuel is uniformly distributed in the circumferential direction in the furnace after the fall. Further, as described above, the fuel supply port 21B of the fuel supply pipe 21 faces outward in the furnace radial direction, the position thereof is separated from the center line 7 in the furnace radial direction, and is further caused by the rotation of the fuel supply pipe 21. Since the centrifugal force acts, the solid fuel is distributed over a wide range reaching outward in the radial direction of the furnace.

  In the present embodiment, as described above, combustion air is blown inward in the furnace radial direction from the plurality of air supply pipes 22 toward the fuel supply port 21B. As a result, the solid fuel scattered outward from the fuel supply port 21B of the fuel supply pipe 21 in the furnace radial direction is pushed back inward in the same direction by the combustion air, and is distributed widely and evenly in the same direction. In other words, if the solid fuel is simply dropped and supplied with the fuel supply port 22 facing outward in the radial direction of the furnace, the solid fuel is distributed in the same direction and away from the furnace center. There may be insufficient solid fuel falling in the vicinity. As in this embodiment, by blowing combustion air inward from the air supply pipe 22 in the radial direction of the furnace, not only oxygen for combustion is supplied, but the falling solid fuel is also changed by the flow rate. It will be dispersed in the furnace radial direction. As a result, the solid fuel is distributed near the center, and the distribution is kept uniform.

  In the apparatus of this embodiment having such a configuration, the raw material is fired in the following manner.

  In FIG. 1, the raw material S falls from the upper storage device 17A and is stored in the lower storage device 17B while the inflow of air from the outside is blocked by the rotary valve 18.

  The raw material in the lower storage device 17B falls through the raw material supply pipe 19 to form a primary deposition layer of the raw material on the hearth 6 that forms the bottom surface of the preheating space 16. This primary deposited layer forms an upper free surface 31 on the raw material supply pipe 19 side and a lower free surface 32 on the combustion chamber 15 side with an angle of repose.

  The solid fuel slides down in the fuel supply pipe 21 and is discharged from the fuel supply port 21 </ b> B and dropped into the combustion chamber 15. At this time, as described above, the solid fuel is charged outward in the furnace radial direction and pushed back to the combustion air blown inward in the same direction from the air supply pipe 22 to be primarily deposited on the hearth 6. Dispersed and distributed on the surface of the layer and on the surface 33A of the secondary deposition layer 33 formed in the furnace body 9.

  The raw material of the primary deposition layer on the hearth 6 in the preheating space 16 includes the radiant heat transfer from the combustion gas in the combustion chamber 15 and the heating on the lower free surface 32 by the combustion of solid fuel in the primary deposition layer. Then, it is semi-fired by heating with the combustion gas flowing from the combustion chamber 15 through the inside of the primary deposition layer.

  As described above, a plurality of pushers 16A guided by the outer cylinder portion 3 and capable of reciprocating in the radial direction of the furnace are installed around the outer cylinder portion 3, and the primary deposition layer is formed by the action thereof. The semi-baked raw material is extruded from the vicinity of the lower part of the lower free surface 32 toward the dropping port 6A and dropped. The hearth 6 rotates around the center line 7 that is the vertical center axis, and the primary deposited layer on the hearth 6 also rotates along with this, but the pusher 16A is supported by the outer cylinder portion 3 fixed in the space. Since it does not move in the circumferential direction but reciprocates only in the radial direction, the pusher 16A pushes the primary deposition layer of the raw material relatively moving in the circumferential direction evenly in the circumferential direction.

  The semi-fired raw material fired by heating in the primary deposition layer on the rotating hearth 6 falls from the lower free surface 32 side through the drop port 6A in the center of the hearth 6 by the action of the pusher 16A, and the furnace body 9 A secondary deposition layer is formed within. In the furnace body 9, the semi-fired raw material is fed from the outside through the air supply pipe 10, reacts positively with the air rising in the secondary deposition layer, contacts the air during the descent, and is completely fired. Then it is cooled. Thus, the fired raw materials are sequentially taken out of the furnace as products from the outlet 14 provided in the lower part of the furnace body 9. Since the secondary deposition layer 33 is gently settled by taking out the product from the outlet 14, the coarse and solid fuel dispersed and distributed on the surface 33A of the secondary deposition layer 33 is continuously dropped into the granular raw material. It is taken in and settles in the same way.

  The granular raw material falling from the dropping port 6A is at a high temperature, and due to the heat radiation from the combustion flame in the combustion chamber 15, the coarse granular solid fuel is heated in the vicinity of the surface 33A of the secondary deposition layer 33. When volatile matter is present, it undergoes thermal decomposition and generates combustible gas. The combustible gas burns in the combustion chamber 15.

  After the above coarse granular solid fuel is thermally decomposed, it becomes a solid and a granular substance with a high carbon content. In the case of coke and char with a small volatile content, almost no combustible gas is generated. The particulate matter containing a large amount of carbon obtained from the above solid fuel slowly settles in the secondary deposition layer 33 in the furnace body 9 of FIG. 1 by taking out the product from the outlet 14. The air fed from the air pipe 10 at the bottom of the furnace body 9 cools the baked product while flowing up through the secondary deposition layer 33 and at the same time, is heated to a high temperature by itself, and the secondary deposition layer. At the top of 33, the carbon-rich particulate matter in the bed is burned.

  The combustion in the secondary deposition layer 33 is carried out in the voids of the raw material grains above the secondary deposition layer 33, so that the heat energy generated by the combustion is directly transmitted to the raw material, Bake. At that time, in the present invention, the solid fuel is widely distributed both in the radial direction and in the circumferential direction, so that the heating of the raw material is uniformly performed in a wide range.

  In the case where cooling is performed using an amount of air that is less than the amount of air necessary for complete combustion of solid particles having a high carbon content that settles in the secondary deposition layer 33 in the furnace body 9, Combustion is incomplete, and the combustion gas flowing upward from the secondary deposition layer 33 contains carbon monoxide. The carbon monoxide is completely combusted in the combustion chamber 15 by the air sent from the air supply pipe 22 to the combustion chamber 15.

  The high-temperature combustion gas generated by combustion in the combustion chamber 15 flows upward through the primary deposition layer in the preheating space 16 of FIG. 1 to heat the raw material of this primary deposition layer. At that time, a part of the raw material is heated to a high temperature. The exhaust gas exiting the preheating space 16 is exhausted from a plurality of exhaust gas conduits 20.

<Second embodiment>
The second embodiment is different from the first embodiment in that a plurality of holes are formed in the peripheral wall of the fuel supply pipe and a fuel supply pipe is configured by connecting a plurality of curved pipes. Hereinafter, the second embodiment will be described based on FIG. 3 with a focus on differences from the first embodiment.

  FIG. 3 is a longitudinal sectional view of a fuel supply pipe provided in the vertical firing furnace according to the second embodiment. Parts common to the first embodiment are denoted by the same reference numerals and description thereof is omitted. As shown in FIG. 3, the inner peripheral surface of the opening and the inner peripheral surface of the tubular portion 23 formed in the central portion of the furnace lid 1 that allows the fuel supply pipe 41 to penetrate, the outer peripheral surface of the fuel supply pipe 41, A space 42 is formed between them. In the present embodiment, the peripheral wall of the fuel supply pipe 41 is provided with a plurality of holes 43 that open toward the space 42. The flange 41A formed on the outer peripheral surface of the fuel supply pipe 41 corresponds to the flange 21A in the first embodiment.

  The fuel supply pipe 41 receives air from the outside together with the solid fuel and discharges them to the combustion chamber 15 from the fuel supply port 41B which is the lower end opening. At this time, a large amount of air is blown out and diffused into the space 42 from the hole 43 formed in the peripheral wall of the fuel supply pipe 41 and sent to the combustion chamber 15, and the remaining air is sent to the combustion chamber 15 from the fuel supply port 41 </ b> B. Sent out. The air sent out from the hole 43 to the blowout combustion chamber 15 stirs the powdered fuel that can be scattered with a small diameter out of the combustion gas in the combustion chamber 15 and the solid fuel, and also gives oxygen for these combustion. Solid fuel is burned well over a wide range. The air coming out of the fuel supply port 41B of the fuel supply pipe 41 sends out the solid fuel further by its flow rate. Further, since the hole 43 is opened toward the space 42 which is a region where combustion is most actively performed in the combustion chamber 15 and requires a lot of oxygen, the combustion in the combustion chamber 15 is better. It will be a thing.

  The fuel supply pipe 41 is configured by connecting three bent pipes of an inlet bent pipe 44, an intermediate bent pipe 45, and an outlet bent pipe 46 in this order. A flange 47 is provided at the lower end of the inlet curved pipe 44, flanges 48 and 49 are provided at the upper and lower ends of the intermediate curved pipe 45, and a flange 50 is provided at the upper end of the outlet curved pipe 46. The inlet curved pipe 44 passes through the space 42 formed in the furnace lid 1 and the cylindrical member 23. The flange 47 of the inlet curved pipe 44 and the flange 48 of the intermediate curved pipe 45 are fastened with a bolt illustrated by a one-dot chain line, and the inlet curved pipe 44 and the intermediate curved pipe 45 are connected. Further, the flange 49 of the intermediate curved pipe 45 and the flange 50 of the outlet curved pipe 46 are fastened with bolts, and the intermediate curved pipe 45 and the outlet curved pipe 46 are connected. As shown in FIG. 3, the fuel supply pipe 41 configured by connecting three curved pipes as described above has a continuous curve at the lower end, and the curve gradually decreases toward the lower end with respect to the horizontal plane. It has become. Accordingly, the fuel supply port 41B is located away from the center axis of the furnace in the radial direction of the furnace and faces outward in the same direction.

  In this way, if the fuel supply pipe 41 is configured by connecting a plurality of curved pipes, the length of the fuel supply pipe 41, that is, the position of the opening in the furnace radial direction can be easily adjusted by increasing or decreasing the number of curved pipes. it can. As a result of this adjustment, the lower end opening of the fuel supply pipe 41, which is an inlet for the solid fuel, moves away from the furnace center if the fuel supply pipe 41 is lengthened, and approaches the center of the furnace if the fuel supply pipe 41 is shortened. The distribution of the fuel in the furnace radial direction can be adjusted. That is, if the fuel supply pipe 41 is lengthened, a large amount of solid fuel can be distributed at positions away from the center of the furnace, and if the fuel supply pipe 41 is shortened, a large amount of solid fuel is distributed near the center of the furnace. Can do. For example, when the outlet curved pipe 46 is removed and the length of the fuel supply pipe 41 is shortened, the opening serving as the solid fuel inlet becomes the lower end opening of the intermediate curved pipe 45. Therefore, compared with the state before the outlet bent tube 46 is removed, the solid fuel inlets are located more inwardly in the radial direction of the furnace, and the solid fuel is more distributed at a position closer to the center of the furnace.

  Further, by changing the length of the fuel supply pipe 41 by increasing / decreasing the number of curved pipes, not only the opening position can be adjusted, but also the direction in which the solid fuel is discharged can be adjusted. As shown in FIG. 3, the direction in which the lower end openings of the inlet curved pipe 44, the intermediate curved pipe 45, and the outlet curved pipe 46 are directed is gradually in the order of the outlet curved pipe 46, the intermediate curved pipe 45, and the inlet curved pipe 44. Close to the horizontal direction. Therefore, for example, when the fuel supply pipe 41 is configured by the inlet curved pipe 44, the intermediate curved pipe 45, and the outlet curved pipe 46, the opening is smaller than when the fuel supply pipe 41 is configured by only the inlet curved pipe 44. In addition to being located largely outward in the furnace radial direction, the gas is directed with an inclination close to the horizontal direction, and solid fuel is discharged further in the furnace radial direction.

  In the present embodiment, the fuel supply pipe 41 is constituted by three curved pipes, but the number of the curved pipes constituting the fuel supply pipe 41 is not limited to this, and may be more or less than three. In addition, the curved pipes are connected to each other by providing flanges on the curved pipes and fastening them with bolts, but the means for connecting the curved pipes is not limited to this.

<Third embodiment>
The third embodiment is different from the first embodiment in that an air supply pipe that disperses the solid fuel released from the fuel supply pipe 21 and reflects the solid fuel to disperse the solid fuel in a wide area is provided in the furnace lid. Hereinafter, the third embodiment will be described based on FIG. 4 with a focus on differences from the first embodiment.

  FIG. 4 is a diagram showing an air supply pipe in the third embodiment. In the present embodiment, a fuel supply pipe 21 for supplying solid fuel into the furnace is provided at the center position of the furnace lid (not shown) as in the case of the first embodiment. Around the center position of the furnace lid, a plurality of straight pipe air supply pipes 60 for supplying combustion air into the furnace are provided so as to face downward and inward in the furnace radial direction. A part of the outer peripheral surface of the tip of the air supply pipe 60 is notched, and a flat surface 60A parallel to the axial direction is formed. As shown in the figure, the fuel supply port 21 </ b> B of the fuel supply pipe 21 is directed to the tip of the air supply pipe 60. The air supply pipe 60 is rotatable around the axis of the air supply pipe 60, and while the solid fuel is supplied from the fuel supply pipe 21, the air supply pipe 60 blows combustion air from the air supply port 60B, It is driven by a drive unit (not shown) and rotates around the axis as shown by an arrow in FIG.

  In this embodiment of the apparatus having such a configuration, the solid fuel discharged from the fuel supply port 21B hits the tip of the air supply pipe 60, is reflected at a wide angle, and falls downward. By applying the solid fuel to the air supply pipe 60 and reflecting it at a wide angle in this way, the solid fuel is distributed in a wide range in the furnace, so that the distribution of the solid fuel in the furnace is made uniform over a wide range. It is done. Further, a part of the reflected solid fuel is pushed back inward in the furnace radial direction by the combustion air blown from the air supply port 60B, and falls near the furnace center. As a result, the distribution of the solid fuel can be made more uniform.

  When the flat surface 60A of the air supply pipe 60 faces the fuel supply port 21B side of the fuel supply pipe 21 during the rotation of the air supply pipe 60, the solid fuel hits the flat surface 60A as shown in FIG. , Broaden the range and reflect. When the outer peripheral surface other than the flat surface 60 </ b> A of the air supply pipe 60, that is, the curved surface faces the fuel supply port 21 </ b> B side, the solid fuel hits the curved surface and is reflected, but when the solid fuel hits the curved surface of the air supply pipe 60. Compared with the case of hitting the flat surface 60A, the light is reflected at a wider angle. Thus, by rotating the air supply pipe 60 around the axis and selecting either the flat surface 60A or the curved surface as the reflecting surface, the angle at which the solid fuel is reflected can be adjusted. Further, when the air supply pipe 60 is continuously rotated, the reflection on the flat surface 60A and the reflection on the curved surface are periodically repeated, and the solid fuel is dispersed in a very wide range by both reflections. Furthermore, the distribution range of the solid fuel in the furnace can also be adjusted by adjusting the rotation and stop of the air supply pipe 60, the rotation speed, and the like by the drive unit.

  In the present embodiment, a plurality of such air supply pipes 60 may be provided around the fuel supply pipe 21 in the furnace lid, or the air supply pipe 60 and the first embodiment around the fuel supply pipe 21 may be provided. You may mix the air supply pipe | tube 22 shown by. The reflecting surface may be formed as a member provided separately from the air supply pipe.

It is a longitudinal section of the device of the first embodiment of the present invention. It is a figure which shows the detail of a structure above the furnace cover shown in FIG. It is a longitudinal cross-sectional view of the fuel supply pipe provided in the vertical firing furnace which concerns on 2nd embodiment. It is a figure which shows the air supply pipe | tube in 3rd embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Furnace 6 Hearth 6A Drop port 9 Furnace body 14 Outlet 15 Combustion chamber 16 Preheating space 21 Fuel supply pipe 21B Fuel supply port 27 Drive device

Claims (6)

An annular hearth that rotates around a vertical axis and has a material drop opening formed in the center thereof, and a furnace lid that is fixedly disposed at an upper position of the hearth, An inner cylinder portion having an outer diameter larger than the dropping port and continuously provided on the furnace lid, and an outer cylinder portion connected to the inner cylinder portion at an upper portion are provided, and the outer cylinder portion is formed from the inner cylinder portion. The furnace lid is provided with a fuel supply port for supplying solid fuel from the outside to the combustion chamber formed immediately below, and between the furnace floor and the lower end of the outer cylinder part. An airtight sealing device is provided to the outside to allow relative rotation of the hearth with respect to the hearth lid, and an annular cylinder formed by being surrounded by the inner and outer cylinders connected at the top and the hearth. The preheating space is provided with a raw material supply pipe for supplying raw material to the preheating space from the outside, and the preheating space communicates with the combustion chamber. Opened radially inward, a vertical cylindrical furnace body extends downward from the edge of the drop port formed in the center of the hearth, and the raw material in the preheating space is placed in the combustion chamber. A vertical firing furnace in which an outlet is formed at the lower part of the furnace main body so as to fall from the facing side, and an outlet for taking out the raw material that has fallen from the dropping port and fired in the furnace main body as a product The fuel supply port is formed by a lower end opening of a fuel supply pipe that enters the furnace toward the combustion chamber at the center of the furnace lid, and the lower end opening of the fuel supply pipe opens outward in the radial direction of the furnace. In addition, a vertical line passing through the center of the furnace lid is used as a furnace axis to be rotated by a driving device , and the fuel supply pipe receives air together with solid fuel and supplies them from the lower end opening. And a plurality of fuel supply pipes on the peripheral wall. Vertical firing furnace, characterized by being adapted to blow air into the combustion chamber parts is formed from the hole portion.   The vertical firing furnace according to claim 1, wherein the lower end opening of the fuel supply pipe is located away from the furnace axis in the furnace radial direction.   The furnace cover is provided with a plurality of air supply ports distributed in the circumferential direction at positions away from the furnace axis in the furnace radial direction, and combustion air is blown into the combustion chamber from the air supply ports. The vertical firing furnace according to claim 1 or 2.   The vertical firing furnace according to claim 3, wherein the air supply port is located outward in the furnace radial direction from the lower end opening of the fuel supply pipe and is directed inward in the furnace radial direction. The hole portion is provided so as to open toward a space formed between an inner peripheral surface of an opening of a furnace lid that allows penetration of the fuel supply pipe and an outer peripheral surface of the fuel supply pipe. A vertical firing furnace according to any one of claims 1 to 4 . The vertical firing furnace according to any one of claims 1 to 5 , wherein the driving device is outside the furnace and drives an outside part of the fuel supply pipe.

Images