Internal circulation boiling calcining kiln air distribution plate supported by central pipe and mounting structure of internal circulation boiling calcining kiln air distribution plate

Abstract

The invention discloses an internal circulation boiling calcining kiln air distribution plate and a mounting structure thereof.The air distribution plate comprises an annular air distribution plate body, a supporting center pipe and a hollow center blind island, the bottom of the center blind island extends downwards to form a sleeve, and the supporting center pipe is mounted in the sleeve; the upper end of the supporting center pipe penetrates into and is fixed in the center blind island, the lower end of the supporting center pipe penetrates out of the lower portion of the sleeve, and the annular air distribution plate body annularly sleeves and is fixed to the circumferential outer side of the center blind island; in the installation structure, the annular air distribution plate body in the air distribution plate is installed at the communication position of the internal circulation boiling calcining kiln and the air chamber. According to the invention, the influence of thermal deformation caused by thermal expansion and thermal contraction in the clinker calcining process is reduced, the high-temperature bearing capacity is high, and the uniformity of a fluidized bed layer is facilitated.

Description

Technical Field

[0001] The invention relates to the field of calcining kiln air distribution plates, in particular to an inner circulation boiling calcining kiln air distribution plate supported by a central tube and a mounting structure thereof. Background Art

[0002] Internal circulation boiling calcining kiln is a kind of production equipment widely used in cement, chemical, metallurgy and other industries, and the air distribution plate is the core component of the internal circulation boiling calcining kiln. In a high temperature and thermal environment, its stability and reliability are particularly important, which determines the durability of the entire firing system and the operation rate of the system. In addition to the requirements for the uniformity of the airflow field, concentration field and atmosphere field in the fluidized bed, the internal circulation boiling calcining technology has higher and higher performance requirements for the installation structure of the fluidized bed and the porous plate material as the production scale continues to expand, which determines the large-scale degree of production. Therefore, how to choose the right material, what kind of structure to adopt, and build a bed structure with strong heat resistance, durability, reliability and safety to meet the needs of large-scale or large-scale internal circulation boiling calcining kiln production system construction, a central tube independently supported air distribution plate construction form and its structural support are patented technologies developed to solve this problem.

[0003] The performance of the air distribution plate has an important impact on the fluidization quality of the entire internal circulation boiling calcining kiln and the quality of subsequent products. The existing air distribution plates for fluidized beds have the following problems with the increase of the working temperature in the reactor and the expansion of the production scale: (1) As the working temperature in the reactor increases, the requirements for the oxidation resistance, thermal shock resistance, deformation resistance and tolerance of the air distribution plate material become higher and higher. Especially when the temperature in the fluidized bed reactor reaches above 1000°C and the temperature difference between the upper and lower parts is large, thermal deformation has a greater impact on the bearing capacity.

[0004] (2) As the scale expands, the air distribution board needs a stronger bearing capacity. As the span of the air distribution board increases, a single frame support is difficult to apply. Therefore, the support structure of the air distribution board needs a more reasonable design.

[0005] The central tube-supported air distribution plate and its installation structure provided by the present invention can effectively solve the above problems. Summary of the invention

[0006] The present invention provides an inner circulation boiling calcining kiln air distribution plate supported by a central tube and its installation structure, so as to solve the problems of the inner circulation boiling calcining kiln air distribution plate in the prior art that the bearing capacity is greatly affected by thermal deformation, the bearing capacity is insufficient, and the flow field distribution is affected.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is: The center support tube is used for center blind island support (such as Figure 1As shown in the figure), the annular platform of the hollow island should be kept on the same plane as the outer annular platform; an inverted basin-shaped platform ( Figure 1 ), used to form a central blind island structure independent of the porous bed plate; the lower edge of the central blind island platform and the outer side of the central tube are welded with a closed round platform (square platform) to enhance the strength and stability of the central blind island platform structure ( Figure 1 );, the above components constitute the overall structure of the central blind island,, the outside of the central blind island is provided with fire-resistant insulation materials, and the inside of the central blind island is provided with a connected ventilation and cooling device; an annular gap structure is formed between the central blind island and the external shell; the central blind island and the top of the external shell are provided with an annular groove for supporting a porous plate, and the bottom annular support plane is maintained on the same plane as the external annular support plane; a plurality of fan-shaped air distribution plates are arranged in the groove around the central blind island, and the two ends of the air distribution plates are respectively supported on the support platform surface of the external annular shell and the support platform surface of the internal central blind island, forming a complete annular air distribution plate structure ( Figure 2 ); at least one of the annular air distribution plates has a discharge hole that vertically penetrates the annular air distribution plate body. Further, the annular air distribution plate body is formed by splicing a plurality of fan-shaped annular plates along the circumference of the central blind island, each fan-shaped annular plate has a plurality of air holes that vertically penetrate the fan-shaped annular plate, and at least one fan-shaped annular plate has a discharge hole that vertically penetrates the fan-shaped annular plate near its outer circumferential edge.

[0008] Furthermore, the annular air distribution plate body is formed by a plurality of fan-shaped plates spliced ​​together along the circumference of the central blind island, and each fan-shaped plate has a plurality of air holes vertically penetrating the fan-shaped plate, wherein at least 2 to 4 fan-shaped plates are provided with discharge holes vertically penetrating the fan-shaped plates (need to be evenly distributed circumferentially) near the edge of their own outer circumference.

[0009] Furthermore, the fan annular plate with a discharge hole is provided with a plurality of air supply channels near the discharge hole, each air supply channel is an inclined hole penetrating the fan annular plate, and the upward extension line of the central axis of the inclined hole intersects with the upward extension line of the central axis of the discharge hole on the fan annular plate, and the high-speed wind passing through the inclined hole can blow up the material.

[0010] Furthermore, the central blind island is composed of an inverted cavity auxiliary steel platform, a main steel platform, an annular inverted cone stabilizing structure, etc. The central blind island and the interior of the central support tube are interconnected and are provided with a cooling device.

[0011] Furthermore, the air inlet channel and the air outlet channel should be designed separately, and the air inlet channel is between the force-bearing support steel pipe and the central air outlet pipe, and the central air outlet pipe should be connected to the external air duct; thermocouples need to be set on the inner surface of the support force pipe and inside the top central blind island to sense temperature changes and judge the internal temperature changes; 6. The outside of the central support pipe according to claim 1 is provided with high-temperature wear-resistant insulation material. In order to stabilize the refractory material of the central support pipe, anchors of a certain size need to be evenly and reasonably welded to prevent the refractory material from falling off; Furthermore, adjacent fan annular plates are embedded in each other and spliced ​​together, or spliced ​​together through step matching, and heat-resistant flexible metal material layers are respectively provided at the interfaces of adjacent fan annular plates.

[0012] Furthermore, the circumferential outer side surface of the central blind island has an annular groove, and the center ring hole of the annular air distribution plate body formed by splicing each fan annular plate is embedded and fixed in the annular groove of the central blind island.

[0013] Furthermore, a crossbeam is fixed inside the central blind island, and the upper end of the supporting central tube is fixedly connected to the crossbeam.

[0014] Furthermore, a heat-insulating refractory layer is provided on the circumferential outer wall of the supporting central tube.

[0015] Furthermore, the installation structure of the air distribution plate of the internal circulation boiling calcining kiln mentioned above includes a calcining kiln and an air chamber in the internal circulation boiling calcining kiln, both of which are axially vertical, the air chamber is connected from top to bottom, the top of the air chamber is open to form an opening, and the lower part of the air chamber is expanded to form a bell-mouth section; the bottom of the calcining kiln is open, the calcining kiln is arranged above the air chamber, and the bottom opening of the calcining kiln is coaxially opposite to the top opening of the air chamber; The annular air distribution plate body in the air distribution plate is coaxially mounted on the top opening of the air chamber and is sealed on the bottom opening of the calcining kiln at the same time, so that the central blind island in the air distribution plate is located in the middle of the connection between the air chamber and the calcining kiln; the outer diameter of the annular air distribution plate body is larger than the outer diameter of the top opening of the air chamber, so that the circumferential edge of the annular air distribution plate body exceeds the edge of the top opening of the air chamber to form an overhanging portion, and the calcining kiln and the air chamber are connected by the air holes of the annular air distribution plate body; a steel structure bracket is fixed circumferentially at the top of the air chamber, and the bottom of the overhanging portion of the annular air distribution plate body in the air distribution plate is supported by the steel structure bracket; The sleeve extended from the bottom of the central blind island extends downward into the air chamber, and the air inlet of the air chamber is formed by the annular gap between the bell-shaped lower part of the sleeve and the bell-shaped section of the lower part of the air chamber, and the chamber cavity of the air chamber is formed by the annular gap between the upper part of the sleeve and the upper part of the air chamber, and the steel structure support supporting the central tube and the circumferential outer wall of the top of the air chamber cooperates to support the overall structure of the annular air distribution plate body and the central blind island.

[0016] Furthermore, a heat insulation material layer is provided between the contact surface of the steel structure support and the protruding portion of the air distribution plate.

[0017] Compared with the prior art, the hollow tube independent support central blind island platform structure provided by the present invention has the following advantages: (1) The supporting structure is simple and easy to manufacture and install, while also having high load-bearing capacity and high temperature resistance.

[0018] (2) The air chamber of the distribution plate of the present invention has little influence on the flow field, and there is no supporting structure in the air chamber, so the airflow entering the calcining kiln through the air chamber is more uniform. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a front view of the air distribution plate installation structure according to an embodiment of the present invention.

[0020] Figure 2 It is a top view of the air distribution plate according to an embodiment of the present invention.

[0021] Figure 3 It is a structural diagram of a splicing method of adjacent fan annular plates in an embodiment of the present invention.

[0022] Figure 4 It is a structural diagram of another splicing method of adjacent fan annular plates in an embodiment of the present invention. DETAILED DESCRIPTION

[0023] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0024] like Figure 1 As shown, this embodiment discloses an air distribution plate for an internal circulation boiling calcining kiln, comprising a hollow central blind island 4, a central support pipe 6, and an annular air distribution plate body 2. The central blind island 4 is vertically arranged, and the annular air distribution plate body 2 is coaxially sleeved on the circumferential outer side of the central blind island 4 through its own annular hole. The middle position of the bottom of the central blind island 4 extends downward to form a sleeve 4.1, and the upper part of the sleeve 4.1 is an annular inverted cone stabilizing structure 4.2. There is a main steel platform 4.3 inside the central blind island, and an inverted cavity auxiliary steel platform 4.4 is provided at the upper end of the main steel platform. The central support tube 6 is coaxially installed in the sleeve 4.1. The outer diameter of the central support tube 6 is consistent with the inner diameter of the upper part of the sleeve 4.1 which is in a straight cylindrical shape. The upper end of the central support tube 6 extends upward to penetrate into the central blind island 4. A crossbeam is fixed in the central blind island 4. The upper end of the central support tube 6 is fixedly connected to the crossbeam. The lower end of the central support tube 6 passes downward from the lower part of the sleeve 4.1. A cooling air duct 6.1 is installed inside the central support tube 6. The cooling air enters the central blind island 4 from the gap between the cooling air duct 6.1 and the central support tube 6 to cool the entire central blind island 4, and then is discharged through the cooling air duct 6.1.

[0025] In this embodiment, the annular air distribution plate body 2 includes a plurality of fan annular plates 2.1, each of which is distributed around the outer side of the central blind island and spliced ​​to form an axially vertical complete annular air distribution plate body 2. The outer circumferential wall of the central blind island 2 has an annular groove, and the central annular hole of the annular air distribution plate body 2 spliced ​​by the fan annular plates 2.1 is embedded and fixed in the annular groove of the outer circumferential wall of the central blind island 4.

[0026] like Figure 2 As shown, in this embodiment, each fan annular plate 2.1 has a plurality of air holes 2.2 that vertically penetrate the fan annular plate, and at least one fan annular plate is also provided with a discharge hole that vertically penetrates the plate body of the fan annular plate near its outer circumferential edge, and a discharge pipe 3 is connected and installed at the lower end of the discharge hole. In the fan annular plate with a discharge hole 2.3, a plurality of air supply channel holes 2.4 are respectively provided near the discharge hole, and the axial direction of each air supply channel hole is not parallel to the axial direction of the air distribution plate, and each air supply channel hole 2.4 obliquely penetrates the plate body of the fan annular plate, that is, each air supply channel hole 2.4 is an oblique hole, and the upward extension line of the central axis of the oblique hole intersects with the upward extension line of the central axis of the discharge hole on the fan annular plate 2.1, thereby making the upper end of the air supply channel hole 2.4 face directly above the corresponding discharge hole 2.3, and the lower end of the air supply channel hole 2.4 is away from the corresponding discharge hole. The air flow from the air supply channel hole 2.4 can form a fluidized air curtain area above the discharge port 2.3.

[0027] In the annular air distribution plate body 2 of this embodiment, the annular fan annular plates 2.1 adjacent to each other are embedded in each other or are spliced ​​together in a step-matched manner. Figure 3 As shown, in the annularly adjacent fan ring plates 2.1, the edge of the first fan ring plate has an embedding opening, and the edge of the second fan ring plate has a clamping piece. When splicing, the clamping piece on the edge of the second fan ring plate is embedded in the embedding opening on the edge of the first fan ring plate. Or as Figure 4 As shown, in the annularly adjacent fan-shaped plates, the edge of the first fan-shaped plate has a step, and the edge of the second fan-shaped plate has another step that is a mirror image of the step of the first fan-shaped plate. When spliced, the steps on the edges of the two fan-shaped plates match each other in a step manner, so that the annularly adjacent fan-shaped plates are spliced ​​together.

[0028] In this embodiment, all the interfaces of the fan annular plates 2.1 are respectively provided with heat-resistant flexible metal material interlayers, which can further dissipate, absorb and alleviate the thermal stress caused by changes in the working temperature environment, and all steel surfaces are cast with refractory materials.

[0029] The central blind island 4 and the fan annular plate 2.1 constituting the annular air distribution plate body 2 of this embodiment are both formed in one step by high-temperature resistant and oxidation-resistant high-strength materials and high-strength fiber materials (for example, alloy material fibers, ceramic fibers, etc.). The specific high-temperature resistant and oxidation-resistant high-strength materials are aggregates and heat-resistant cement with the same performance requirements, plus a certain amount of high-temperature resistant and oxidation-resistant high-strength fiber materials, which are cast and formed in one step by a special construction process, or special ceramic materials (such as silicon nitride, silicon carbide, etc.) and microcrystalline ceramic materials are formed in one step by a special manufacturing process and sintered.

[0030] The central support tube 6 of this embodiment can be made of heat-resistant steel, and the wall thickness can be determined by the top bearing capacity according to the size of the production scale. The circumferential outer surface of the central support tube 6 is provided with a heat-insulating refractory material layer, and the lower end of the central support tube 6 can be supported and fixed on the external platform base. The upper end of the central support tube 6 is fixedly connected to the crossbeam inside the central blind island 4, so that when the cooling air enters the central support tube 6 from the lower end of the central support tube 6, it can enter the central blind island 4 through the upper end of the central support tube 6. The cooling air entering the central blind island 4 can evenly cool the central blind island 4, preventing local structural failure caused by heat accumulation and causing safety problems. In order to prevent the temperature of the central support tube 6 from being abnormal, a thermocouple needs to be set inside the central support tube 6 to meet the needs of internal temperature monitoring.

[0031] The annular air distribution plate body 2 of the present embodiment is installed between the bottom opening of the lower cylinder of the internal circulation boiling calcining kiln 1 and the top opening of the air chamber 5. The top of the air chamber 5 is opened to form an opening, and the lower part of the air chamber 5 gradually expands from the upper straight line to form a bell-mouth section. The bottom opening of the lower cylinder of the calcining kiln 1 and the top opening of the annular air chamber 5 are coaxially opposite to each other.

[0032] The outer diameter of the annular air distribution plate body 2 of the present embodiment is larger than the outer diameter of the opening at the top 5 of the annular air chamber, and the annular air distribution plate body 2 is coaxially installed to cover the opening at the top of the air chamber 5, and the annular air distribution plate body 2 blocks the bottom opening of the lower cylinder of the calcining kiln 1, thereby making the central blind island 4 in the air distribution plate located in the middle of the connection between the air chamber 5 and the calcining kiln 1.

[0033] Since the outer diameter of the annular air distribution plate body 2 is larger than the outer diameter of the top opening of the air chamber 5, the outer circumferential edge of the annular air distribution plate body 2 exceeds the top opening edge of the air chamber 5 to form an overhanging portion, and the discharge pipe 3 is located at the bottom of the overhanging portion of the annular air distribution plate body 2. The air holes 2.2 of each fan annular plate 2.1 in the annular air distribution plate body 2 connect the interior of the lower cylinder of the calcining kiln 1 and the interior of the air chamber 5.

[0034] A support structure is fixed to the circumferential outer wall of the top of the air chamber 5. The support structure is a square frame-shaped steel structure bracket 7, which is welded to the external structural beam and surrounds the top opening of the air chamber 5. The steel structure bracket 7 is supported at the bottom of the protruding portion of the annular air distribution plate body 2, and a heat insulation material layer is provided on the contact surface between the steel structure bracket 7 and the protruding portion of the annular air distribution plate body 2.

[0035] The sleeve 4.1 formed by extending from the bottom of the central blind island 4 extends downward into the air chamber 5, and the annular air inlet of the air chamber 5 is formed by the annular gap between the bell-shaped lower part of the sleeve 4.1 and the bell-shaped section at the lower part of the air chamber 5, and the annular chamber cavity of the air chamber is formed by the annular gap between the upper part of the sleeve 4.1 and the upper part of the air chamber 5.

[0036] In the above structure, the weight of the overall structure of the annular air distribution plate body 2 and the central blind island 4 is jointly supported by the steel structure bracket 7 supporting the central tube 6 and the top circumferential outer wall of the air chamber 5.

[0037] In this embodiment, extremely high requirements are placed on the material and installation structure of the central support tube 6. Since the internal and external support methods and the heating environment are different, it is difficult to ensure that the inside and outside of the air distribution plate 2 are in the same plane, which causes the air distribution plate 2 to be twisted and stressed, affecting its service life. Therefore, it is necessary to use a material with small thermal deformation to make the central support tube 6, preferably a high-strength heat-resistant steel material.

[0038] In this embodiment, the upper end openings of each pore of each fan annular plate 2.1 of the annular air distribution plate body 2 are connected to the lower cylinder of the calcining kiln 1, and the other end openings of each pore 2.2 are connected to the top opening of the air chamber 5, so that the air entering the air chamber can enter the lower cylinder of the calcining kiln 1 through the air holes of the air distribution plate. In the annular air distribution plate body 2, the upper end opening of each discharge pipe 3 is connected to the bottom opening of the lower cylinder of the calcining kiln through the discharge hole 2.3 of the corresponding fan annular plate, and the other end opening of each discharge pipe 3 is connected to the particle controller outside the kiln body. In addition, by setting an oblique air supply channel hole 2.4 on the fan annular plate in the annular air distribution plate body 2, a fluidized air curtain area is formed above the discharge hole 2.3 of the corresponding fan annular plate 2.1, so as to blow up the powdered material that flows through this fluidized air curtain area and enters the particle controller through the discharge pipe.

[0039] During operation, the high-speed air sent by the fan is preheated by the clinker cooling system, and then enters the annular chamber of the air chamber 5 through the air inlet duct. At this time, the air temperature is about 950℃-1250℃. The air flows evenly in the annular chamber 5, and the airflow from the annular chamber of the air chamber passes through the air holes 2.2 on the air distribution plate, and is evenly distributed and sprayed into the lower cylinder of the calcining kiln 1. The injection speed is 60m / s-150m / s. The hot air entering the lower cylinder of the calcining kiln is mixed with the fuel sprayed by the burner and burns rapidly. The temperature rises rapidly to 1250℃-1350℃, and the high-temperature and high-speed gas carries the material upward in a state of repeated surging. With this air distribution plate design, there are more support points for some plates, and the support structure is more stable. At the same time, there is no support pipe in the annular air chamber to interfere with the airflow, and the airflow distribution is more uniform, so that the material above the air distribution plate can be evenly blown up.

[0040] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. The embodiments described in the present invention are merely descriptions of the preferred embodiments of the present invention, and do not limit the concept and scope of the present invention. The various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction, and such combinations should also be regarded as the contents disclosed by the present invention as long as they do not violate the concept of the present invention. In order to avoid unnecessary repetition, the present invention will not further explain various possible combinations.

[0041] The present invention is not limited to the specific details of the above-mentioned embodiments. Within the technical concept of the present invention and without departing from the design concept of the present invention, various modifications and improvements made to the technical solution of the present invention by technical personnel in this field should fall within the protection scope of the present invention. The technical contents for which protection is sought in the present invention have been fully recorded in the claims.

Claims

1. An air distribution plate of an internal circulation boiling calcining kiln supported by a central tube and its installation structure, characterized in that: include: The central support tube is used for supporting the central blind island. The annular platform of the hollow island should be kept on the same plane as the external annular platform. An inverted basin-shaped platform is arranged on the central blind island platform to form a central blind island structure independent of the porous bed plate. A closed round table or square table is welded between the lower edge of the central blind island platform and the outer side of the central tube to enhance the strength and stability of the central blind island platform structure. The above-mentioned components constitute the overall structure of the central blind island. The outside of the central blind island is provided with fire-resistant heat-insulating materials, and the inside of the central blind island is provided with a connected ventilation and cooling device. An annular gap structure is formed between the central blind island and the external shell; an annular groove for supporting a porous plate is provided around the central blind island and on the top of the external shell, and the bottom annular support plane is maintained on the same plane as the external annular support plane; a plurality of fan-shaped air distribution plates are arranged in the groove around the central blind island, and the two ends of the air distribution plates are respectively supported on the support platform surface of the external annular shell and the support platform surface of the internal central blind island, forming a complete annular air distribution plate structure; at least one annular air distribution plate has a discharge hole that passes vertically through the annular air distribution plate body.

2. The air distribution plate of the internal circulation boiling calcining kiln according to claim 1 is characterized in that: The annular air distribution plate body is formed by a plurality of fan-shaped plates spliced ​​together along the circumference of the central blind island, and each fan-shaped plate has a plurality of air holes vertically penetrating the fan-shaped plate, wherein at least 2 to 4 fan-shaped plates are provided with discharge holes vertically penetrating the fan-shaped plates near their own outer circumferential edges.

3. The air distribution plate of the internal circulation boiling calcining kiln according to claim 2 is characterized in that: The fan annular plate with a discharge hole is provided with a plurality of air supply channels near the discharge hole. Each air supply channel is an inclined hole penetrating the fan annular plate. The upward extension line of the central axis of the inclined hole intersects with the upward extension line of the central axis of the discharge hole on the fan annular plate. The high-speed wind passing through the inclined hole can blow up the material.

4. The air distribution plate of the internal circulation boiling calcining kiln according to claim 1 is characterized in that: The central blind island is composed of an inverted cavity auxiliary steel platform, a main steel platform, and an annular inverted cone stable structure. The central blind island and the interior of the central support tube are interconnected and are provided with a cooling device.

5. The central support tube and central blind island internal cooling device according to claim 1, characterized in that: The air inlet channel and the air outlet channel should be designed separately, and the air inlet channel is between the load-bearing supporting steel pipe and the central air outlet duct. The central air outlet duct should be connected to the external air duct. Thermocouples need to be installed on the inner surface of the supporting load-bearing pipe and inside the top center blind island to sense temperature changes and judge the internal temperature changes.

6. According to claim 1, the outside of the central support tube is provided with high temperature wear-resistant insulation material. In order to stabilize the refractory material of the central support tube, anchors of a certain size need to be evenly and reasonably welded to prevent the refractory material from falling off.

7. The air distribution plate of the internal circulation boiling calcining kiln according to claim 2 is characterized in that: Adjacent fan annular plates are embedded in each other and spliced ​​together, or spliced ​​together through step matching, and heat-resistant flexible metal material layers are respectively provided at the interfaces of adjacent fan annular plates.

8. The air distribution plate of the internal circulation boiling calcining kiln according to claim 2 is characterized in that: The circumferential outer side surface of the central blind island is provided with an annular groove, and the central annular hole of the annular air distribution plate body formed by splicing the fan annular plates is embedded and fixed in the annular groove of the central blind island.

9. The air distribution plate of the internal circulation fluidized bed calcining kiln according to any one of claims 1 to 8, characterized in that: A crossbeam is fixed inside the central blind island, and the upper end of the supporting central tube is fixedly connected to the crossbeam.

10. The air distribution plate of the internal circulation fluidized bed calcining kiln according to any one of claims 1 to 8, characterized in that: The circumferential outer wall of the supporting central tube is provided with a heat-insulating refractory layer.

11. An installation structure for an air distribution plate of an internal circulation fluidized bed calcining kiln as claimed in any one of claims 1 to 10, characterized in that: The invention comprises a calcining kiln and an air chamber in an internal circulation boiling calcining kiln, both of which are axially vertical, and an air distribution plate as claimed in any one of claims 1 to 9; the air chamber is connected from top to bottom, the top of the air chamber is open to form an opening, and the lower part of the air chamber is expanded to form a bell-mouth section; the bottom of the calcining kiln is open, the calcining kiln is arranged above the air chamber, and the opening at the bottom of the calcining kiln is coaxially opposite to the opening at the top of the air chamber; The annular air distribution plate body in the air distribution plate is coaxially mounted on the top opening of the air chamber and is sealed on the bottom opening of the calcining kiln at the same time, so that the central blind island in the air distribution plate is located in the middle of the connection between the air chamber and the calcining kiln; the outer diameter of the annular air distribution plate body is larger than the outer diameter of the top opening of the air chamber, so that the circumferential edge of the annular air distribution plate body exceeds the edge of the top opening of the air chamber to form an overhanging portion, and the calcining kiln and the air chamber are connected by the air holes of the annular air distribution plate body; a steel structure bracket is fixed circumferentially at the top of the air chamber, and the bottom of the overhanging portion of the annular air distribution plate body in the air distribution plate is supported by the steel structure bracket; The sleeve extended from the bottom of the central blind island extends downward into the air chamber, and the air inlet of the air chamber is formed by the annular gap between the bell-shaped lower part of the sleeve and the bell-shaped section of the lower part of the air chamber, and the chamber cavity of the air chamber is formed by the annular gap between the upper part of the sleeve and the upper part of the air chamber, and the steel structure support supporting the central tube and the circumferential outer wall of the top of the air chamber cooperates to support the overall structure of the annular air distribution plate body and the central blind island.

12. The installation structure of the air distribution plate of the internal circulation boiling calcining kiln according to claim 11 is characterized in that: A heat insulation material layer is provided between the contact surface of the steel structure support and the protruding portion of the air distribution plate.

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