High-performance alpha alumina calcining device

Abstract

The utility model discloses a kind of high-performance alpha alumina calcining devices, it is related to material processing technical field.The utility model includes pedestal, rotary kiln, cyclone preheater, preheating pipe and cooling channel, the upper end of pedestal is fixed with the head vertical plate and tail vertical plate of relative distribution, one side of head vertical plate close to tail vertical plate is fixed with head sleeve, one side of tail vertical plate close to head vertical plate is fixed with tail sleeve, rotary kiln is rotatably sleeved between head sleeve and tail sleeve, spiral belt is fixed on the inner wall of rotary kiln, and the inside of spiral belt is provided with the arc plate of annular array distribution.The utility model is through being arranged rotary kiln, spiral belt, arc plate, preheating pipe, cyclone preheater, pedestal, cooling channel, solve the excessive accumulation when raw material runs in rotary kiln, the temperature of raw material before feeding is too low, the waste heat of rotary kiln lacks recycling, energy consumption is high, and the problem that alpha alumina calcines cannot be cooled quickly, is easily destroyed crystal form.

Description

Technical Field

[0001] This utility model belongs to the field of materials processing technology, and in particular relates to a high-performance α-alumina calcination device. Background Technology

[0002] Alpha-alumina is the most stable crystalline form of alumina, possessing high hardness, high thermal stability, and low specific surface area. It is widely used in refractory materials, high-end ceramics, and lithium batteries. Alpha-alumina (chemical formula: Al₂O₃) is the most stable of the various allotropes of alumina and is also known as corundum. It is formed at high temperatures (typically above 1300℃) from other alumina phases (such as γ-Al₂O₃). Its crystal structure belongs to the trigonal crystal system, with oxygen ions arranged in a hexagonal close-packed configuration and aluminum ions filling two-thirds of the octahedral voids. This close arrangement endows it with excellent physical and chemical stability. Alpha-alumina is produced from industrial alumina or aluminum hydroxide raw materials, with calcination being an indispensable process. However, the following drawbacks still exist in actual calcination operations: Firstly, when calcining industrial alumina or aluminum hydroxide to form α-alumina, a rotary kiln is generally used. Conventional rotary kilns employ multi-channel low-NOx burners and can use natural gas, liquefied petroleum gas, or light diesel oil. The burners are located at the kiln head, and the flame and temperature field can be precisely adjusted through a control system. The rotary kiln typically uses an internal spiral to rotate and calcine and transport materials. However, this method is prone to material accumulation, resulting in uneven heating, inconsistent α-alumina forming degree, and a reduced yield. Secondly, if the temperature of industrial alumina or aluminum hydroxide raw materials is too low before entering the rotary kiln for calcination, it will increase the energy consumption of the rotary kiln. Furthermore, the excess heat in the exhaust gas of the rotary kiln cannot be recovered, resulting in high overall energy consumption. The hot α-alumina after exiting the kiln should immediately enter a region filled with cold air to achieve rapid cooling in order to "freeze" the crystal form of the α phase and prevent excessive grain growth. However, α-alumina cannot be cooled rapidly after calcination, which can easily damage the crystal form. Utility Model Content

[0003] The purpose of this invention is to provide a high-performance α-alumina calcination device. By setting up a rotary kiln, spiral belt, arc plate, preheating pipe, cyclone preheater, base, and cooling channel, it solves the problems of excessive accumulation of raw materials in the rotary kiln, excessively low temperature of raw materials before feeding, lack of recovery and utilization of waste heat in the rotary kiln, high energy consumption, and the inability to cool α-alumina quickly after calcination, which easily damages the crystal form.

[0004] To solve the above-mentioned technical problems, this utility model is achieved through the following technical solution: This utility model is a high-performance α-alumina calcination device, including a base, a rotary kiln, a cyclone preheater, a preheating pipe, and a cooling channel. The upper end of the base is fixed with a head plate and a tail plate that are relatively distributed. A head sleeve is fixed to the side of the head plate near the tail plate, and a tail sleeve is fixed to the side of the tail plate near the head plate. A rotary kiln is rotatably fitted between the head sleeve and the tail sleeve. A spiral band is fixed on the inner wall of the rotary kiln, and an arc plate arranged in a ring array is provided on the inner side of the spiral band. A cyclone preheater is provided on the upper part of the head sleeve; a cooling channel is provided below the base, a spiral shaft is rotatably connected inside the cooling channel, and a spiral blade is fixedly connected outside the spiral shaft. Two oblique channels are fixedly connected through the upper end of the cooling channel, and a fan is fixed on each oblique channel.

[0005] Furthermore, a geared motor is fixed to the upper end of the base, a main gear is fixed to the output shaft of the geared motor, and a large gear is fixed to the middle of the outer periphery of the rotary kiln, with the main gear meshing with the large gear.

[0006] Furthermore, auxiliary rings are fixed to the outer periphery of both ends of the rotary kiln. Two symmetrically distributed support rollers are provided on the lower outer side of each auxiliary ring. Both ends of the support rollers are rotatably connected to ear plates, and the bottom end of the ear plates is fixed to the base. The cross-section of the support rollers is I-shaped, and the outer periphery of the auxiliary rings is movably embedded in the groove of the support rollers.

[0007] Furthermore, a feed pipe is fixedly connected to the bottom discharge end of the cyclone preheater, and the lower part of the feed pipe extends into the head sleeve, with the bottom end of the feed pipe bent towards the rotary kiln.

[0008] Furthermore, a preheating pipe is fixedly connected to the upper part of the tail sleeve. The upper end of the preheating pipe is bent and fixedly connected to the upper circumference of the cyclone preheater. A hopper is fixedly connected to the upper circumference of the preheating pipe, and a dispersant is fixedly connected to the upper end of the hopper. The height of the connection between the hopper and the preheating pipe is higher than the height of the connection between the preheating pipe and the cyclone preheater.

[0009] Furthermore, a feeding motor is fixed at one end of the cooling channel near the tail plate, and the output shaft of the feeding motor is connected to the screw shaft for transmission. A feeding channel is fixed through the lower part of the tail sleeve, and the bottom end of the feeding channel extends through into the cooling channel.

[0010] Furthermore, the lower cross-section of the cooling channel is semi-circular, and the upper cross-section of the cooling channel is rectangular. A waste heat return channel is fixedly connected to the upper part of the cooling channel away from the feeding motor, and the end of the waste heat return channel away from the cooling channel passes through the head plate and extends into the head sleeve. A discharge pipe is fixedly connected to the lower part of the cooling channel away from the feeding motor.

[0011] This utility model has the following beneficial effects: This invention solves the problem of excessive accumulation of raw materials during operation in a rotary kiln by incorporating a rotary kiln, a spiral belt, and an arc plate. After the raw material enters the rotary kiln, the kiln rotates, and the raw material spirals forward along the spiral belt inside the kiln. Since the material will inevitably accumulate at the bottom of the inner cavity of the rotary kiln, it may accumulate in a concentrated manner. Therefore, this invention reduces the width of the spiral belt and, in conjunction with the arc plate, ensures that the thickness of the raw material accumulation does not exceed the width of the spiral belt. This prevents the industrial alumina or aluminum hydroxide raw materials from accumulating too thickly, thereby ensuring uniform calcination.

[0012] This invention solves the problems of excessively low raw material temperature before feeding, lack of waste heat recovery and utilization in rotary kilns, and high energy consumption by setting up a preheating pipe, a cyclone preheater, and a base. Excess heat and exhaust gas in the rotary kiln are injected into the preheating pipe, and then the feeding equipment is connected from the preheating pipe. The raw material enters the preheating pipe and, together with the heat, enters the cyclone preheater to preheat the industrial alumina or aluminum hydroxide raw material, and also recovers and utilizes the heat in the rotary kiln to achieve circulation.

[0013] This invention solves the problem of α-alumina failing to cool quickly after calcination, which easily damages its crystal structure, by setting up a cooling channel. After the α-alumina is calcined, it is discharged from the feeding channel and enters the cooling channel. Subsequently, it is transported by the spiral shaft and spiral blades. During this process, two fans blow away the heat of the clinker in the cooling channel, forming a rapid cooling effect. At the same time, this heat is input into the kiln head of the rotary kiln through the preheating reflux channel, forming a combustion-supporting effect.

[0014] This invention incorporates a dispersing machine to disperse the incoming raw materials, preventing them from clumping and ensuring that the materials entering the kiln are loose and uniform. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0016] Figure 1 A perspective view of a high-performance α-alumina calcination apparatus; Figure 2 This is a cross-sectional view of a high-performance α-alumina calcination apparatus; Figure 3 Diagram showing the connection between the base and the rotary kiln; Figure 4 This is a structural diagram of the base; Figure 5 This is a structural diagram of a rotary kiln; Figure 6 This is a cross-sectional disassembly diagram of the rotary kiln, head sleeve, and tail sleeve.

[0017] Figure label: 1. Base; 101. Head upright plate; 1011. Head sleeve; 102. Tail upright plate; 1021. Tail sleeve; 1022. Discharge channel; 103. Gear motor; 1031. Main gear; 104. Support roller; 1041. Ear plate; 2. Rotary kiln; 201. Large gear; 202. Auxiliary ring; 203. Spiral belt; 204. Arc plate; 3. Cyclone preheater; 301. Discharge pipe; 4. Preheating pipe; 401. Hopper; 402. Disperser; 5. Cooling channel; 501. Inclined channel; 502. Fan; 503. Spiral shaft; 5031. Spiral blade; 504. Feeding motor; 505. Discharge pipe; 506. Waste heat return channel. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0019] Please see Figure 1-6 As shown, this utility model is a high-performance α-alumina calcination device, including a base 1, a rotary kiln 2, a cyclone preheater 3, a preheating pipe 4, and a cooling channel 5. The upper end of the base 1 is fixed with a head plate 101 and a tail plate 102 that are relatively distributed. A head sleeve 1011 is fixed on the side of the head plate 101 that is close to the tail plate 102, and a tail sleeve 1021 is fixed on the side of the tail plate 102 that is close to the head plate 101. The rotary kiln 2 is rotatably sleeved between the head sleeve 1011 and the tail sleeve 1021. A spiral belt 203 is fixed on the inner wall of the rotary kiln 2, and an arc plate 204 arranged in a ring array is provided on the inner side of the spiral belt 203. The base 1 serves as the mounting carrier, assisting in the movement and installation of the rotary kiln 2. The head upright plate 101 and the tail upright plate 102 are arranged opposite each other. The kiln head of the rotary kiln 2 is fitted inside the head sleeve 1011, and the kiln tail of the rotary kiln 2 is fitted inside the tail sleeve 1021. The rotary kiln 2 can rotate within the head sleeve 1011 and tail sleeve 1021 assembly. The material moves forward spirally along the spiral belt 203 inside the rotary kiln 2. Since the material will inevitably accumulate at the bottom of the inner cavity of the rotary kiln 2, it may accumulate in a concentrated manner. Therefore, this utility model reduces the width of the spiral belt 203 and, in conjunction with the setting of the arc plate 204, ensures that the thickness of the raw material accumulation does not exceed the width of the spiral belt 203. This prevents the industrial alumina or aluminum hydroxide raw materials from accumulating too thickly, thereby ensuring uniform calcination operations. A cyclone preheater 3 is provided on the upper part of the head sleeve 1011; a cooling channel 5 is provided below the base 1, a spiral shaft 503 is rotatably connected inside the cooling channel 5, and a spiral blade 5031 is fixedly connected to the outside of the spiral shaft 503. Two oblique channels 501 are fixedly connected through the upper end of the cooling channel 5, and a fan 502 is fixed on each oblique channel 501. After the raw materials enter, they are preheated in the cyclone preheater 3. Only after reaching a certain temperature can they enter the rotary kiln 2 for centralized calcination. The calcined α-alumina enters the cooling channel 5 and is conveyed by the spiral shaft 503 and spiral blades 5031. The fan 502 is installed in the inclined channel 501 and blows air at an angle towards the α-alumina in the cooling channel 5 to form a rapid cooling effect.

[0020] A geared motor 103 is also fixed at the upper end of the base 1. A main gear 1031 is fixed on the output shaft of the geared motor 103. A large gear 201 is fixed in the middle of the outer periphery of the rotary kiln 2, and the main gear 1031 and the large gear 201 are meshed and connected. The geared motor 103 is used to drive the main gear 1031 to rotate, thereby meshing with the transmission gear 201 to rotate, and then driving the rotating sleeve to rotate.

[0021] Auxiliary rings 202 are fixed to the outer periphery of both ends of the rotary kiln 2. Two symmetrically distributed support rollers 104 are provided on the lower outer side of each auxiliary ring 202. Both ends of the support rollers 104 are rotatably connected to ear plates 1041, and the bottom end of the ear plates 1041 is fixed to the base 1. The cross section of the support rollers 104 is I-shaped, and the outer periphery of the auxiliary rings 202 is movably embedded in the groove of the support rollers 104. Each auxiliary ring 202 is supported on two support rollers 104, and the support rollers 104 are connected to the base 1 through ear plates 1041. When the rotary kiln 2 rotates, the auxiliary ring 202 rotates in the grooves of the two support rollers 104, and at the same time, it can rotate and also plays an auxiliary support role.

[0022] A feed pipe 301 is fixedly connected to the bottom discharge end of the cyclone preheater 3, and the lower part of the feed pipe 301 extends into the head sleeve 1011. The bottom end of the feed pipe 301 is bent towards the rotary kiln 2. The raw material preheated by the cyclone preheater 3 is fed into the rotary kiln 2 through the feed pipe 301.

[0023] A preheating pipe 4 is fixedly connected to the upper part of the tail sleeve 1021. The upper end of the preheating pipe 4 is bent and fixedly connected to the upper circumference of the cyclone preheater 3. A hopper 401 is fixedly connected to the upper circumference of the preheating pipe 4, and a dispersant 402 is fixedly connected to the upper end of the hopper 401. The height of the connection between the hopper 401 and the preheating pipe 4 is higher than the height of the connection between the preheating pipe 4 and the cyclone preheater 3. The exhaust gas and other heat from the rotary kiln 2 enter the preheating tube 4. At the same time, a hopper 401 and a dispersant 402 are installed on the upper part of the preheating tube 4. The dispersant 402 disperses the raw material and feeds it into the hopper 401. The heat from the hopper 401 and the heat from the preheating tube 4 are then fed into the cyclone preheater 3 for preheating.

[0024] A feeding motor 504 is fixed at one end of the cooling channel 5 near the tail upright plate 102, and the output shaft of the feeding motor 504 is connected to the screw shaft 503. A feeding channel 1022 is fixed through the lower part of the tail sleeve 1021, and the bottom end of the feeding channel 1022 extends through into the cooling channel 5. The feeding motor 504 operates, driving the spiral shaft 503 to rotate, which in turn drives the spiral blade 5031 to rotate, thereby conveying the clinker that has entered the cooling channel 5 to the discharge pipe 505.

[0025] The lower section of the cooling channel 5 is semi-circular, and the upper section of the cooling channel 5 is rectangular. A waste heat return channel 506 is fixedly connected to the upper part of the cooling channel 5 away from the feeding motor 504, and the end of the waste heat return channel 506 away from the cooling channel 5 passes through the head plate 101 and extends into the head sleeve 1011. A discharge pipe 505 is fixedly connected to the lower part of the cooling channel 5 away from the feeding motor 504. The heat blown out by the air cooling of the clinker in the cooling channel 5 is output from the waste heat return channel 506 and enters the rotary kiln 2 to form a combustion-supporting effect, while the finally cooled clinker is discharged from the discharge pipe 505.

[0026] The specific working principle of this utility model is as follows: First, the raw material enters the disperser 402. After the disperser 402 disperses the raw material, it is fed into the hopper 401. The heat from the preheating pipe 4 is simultaneously fed into the cyclone preheater 3 for preheating treatment. The heat in the preheating pipe 4 and the cyclone preheater 3 comes from the rotary kiln 2 and is connected through the preheating pipe 4. The raw material, after being preheated by the cyclone preheater 3, is fed into the rotary kiln 2 through the feed pipe 301. The kiln head of the rotary kiln 2 is fitted inside the head sleeve 1011, and the kiln tail of the rotary kiln 2 is fitted inside the tail sleeve 1021. The reduction motor 103 drives the main gear 1031 to rotate, thereby meshing with the transmission gear 201 to rotate, which in turn drives the rotary sleeve to rotate. The material moves forward spirally along the spiral belt 203 inside the rotary kiln 2. This utility model uses the spiral belt... The width of 203 is reduced, and with the setting of the arc plate 204, the thickness of the raw material accumulation will not exceed the width of the spiral belt 203, so as to achieve uniform heating (the burner is located at the kiln head of the rotary kiln 2, which is a public technology and the attached figure is omitted). After the calcination of α-alumina is completed, it is discharged from the feeding channel 1022 and enters the cooling channel 5. The feeding motor 504 works to drive the spiral shaft 503 to rotate, which drives the spiral blade 5031 to rotate, thereby conveying the clinker entering the cooling channel 5 to the discharge pipe 505. During this process, the heat of the clinker in the cooling channel 5 is blown away by two fans 502 to form a rapid cooling effect. At the same time, this heat is input into the kiln head of the rotary kiln 2 through the preheating return channel to form a combustion-supporting effect. Finally, the cooled clinker is discharged from the discharge pipe 505.

[0027] The above are merely preferred embodiments of the present utility model and do not limit the present utility model. Any modifications, equivalent substitutions, or improvements made to the technical solutions described in the foregoing embodiments, or to some of the technical features, shall fall within the protection scope of the present utility model.

Claims

1. A high-performance α-alumina calcination apparatus, comprising a base (1), a rotary kiln (2), a cyclone preheater (3), a preheating tube (4), and a cooling channel (5), characterized in that: The upper end of the base (1) is fixed with a head plate (101) and a tail plate (102) that are relatively distributed. A head sleeve (1011) is fixed on the side of the head plate (101) that is close to the tail plate (102), and a tail sleeve (1021) is fixed on the side of the tail plate (102) that is close to the head plate (101). A rotary kiln (2) is rotatably sleeved between the head sleeve (1011) and the tail sleeve (1021). A spiral band (203) is fixed on the inner wall of the rotary kiln (2), and an arc plate (204) arranged in a ring array is provided on the inner side of the spiral band (203). A cyclone preheater (3) is provided on the upper part of the head sleeve (1011); a cooling channel (5) is provided below the base (1), a spiral shaft (503) is rotatably connected inside the cooling channel (5), and a spiral blade (5031) is fixedly connected outside the spiral shaft (503). Two oblique channels (501) are fixedly connected through the upper end of the cooling channel (5), and a fan (502) is fixed on each oblique channel (501).

2. The high-performance α-alumina calcination apparatus according to claim 1, characterized in that: A geared motor (103) is fixed at the upper end of the base (1). A main gear (1031) is fixed on the output shaft of the geared motor (103). A large gear (201) is fixed in the middle of the outer periphery of the rotary kiln (2), and the main gear (1031) and the large gear (201) are meshed and connected.

3. The high-performance α-alumina calcination apparatus according to claim 1, characterized in that: The rotary kiln (2) has auxiliary rings (202) fixed on the outer periphery of both ends. Each auxiliary ring (202) has two symmetrically distributed support rollers (104) on the lower outer side. Both ends of the support rollers (104) are rotatably connected to ear plates (1041), and the bottom end of the ear plates (1041) is fixed on the base (1). The cross section of the support rollers (104) is I-shaped, and the outer periphery of the auxiliary rings (202) is movably embedded in the groove of the support rollers (104).

4. The high-performance α-alumina calcination apparatus according to claim 1, characterized in that: The bottom discharge end of the cyclone preheater (3) is fixed with a feed pipe (301), and the lower part of the feed pipe (301) extends into the head sleeve (1011), with the bottom end of the feed pipe (301) bent towards the rotary kiln (2).

5. The high-performance α-alumina calcination apparatus according to claim 1, characterized in that: A preheating pipe (4) is fixedly connected to the upper part of the tail sleeve (1021). The upper end of the preheating pipe (4) is bent and fixedly connected to the upper circumference of the cyclone preheater (3). A hopper (401) is fixedly connected to the upper circumference of the preheating pipe (4), and a dispersant (402) is fixedly connected to the upper end of the hopper (401). The height of the connection between the hopper (401) and the preheating pipe (4) is higher than the height of the connection between the preheating pipe (4) and the cyclone preheater (3).

6. The high-performance α-alumina calcination apparatus according to claim 1, characterized in that: The cooling channel (5) is fixed with a feeding motor (504) at one end near the tail plate (102), and the output shaft of the feeding motor (504) is connected to the screw shaft (503) for transmission. The lower part of the tail sleeve (1021) is fixed with a feeding channel (1022), and the bottom end of the feeding channel (1022) extends into the cooling channel (5).

7. The high-performance α-alumina calcination apparatus according to claim 6, characterized in that: The lower section of the cooling channel (5) is semi-circular, and the upper section of the cooling channel (5) is rectangular. A waste heat return channel (506) is fixedly connected to the upper part of the cooling channel (5) away from the feeding motor (504), and the end of the waste heat return channel (506) away from the cooling channel (5) passes through the head plate (101) and extends into the head sleeve (1011). A discharge pipe (505) is fixedly connected to the lower part of the cooling channel (5) away from the feeding motor (504).

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