Efficient rotary kiln for barite calcination

Abstract

The invention discloses an efficient rotary kiln for barite calcination, and belongs to the technical field of rotary kilns.The efficient rotary kiln comprises a fixed shell, a rotary cylinder, a preheating cylinder, a feeding mechanism and a heating mechanism, the interior of the rotary cylinder is hollow to form a calcining chamber, and the outer surface of the rotary cylinder is provided with spiral teeth extending in the spiral direction and a plurality of material shoveling plates extending in the axial direction; the spiral direction of the spiral teeth is the same as the rotating direction of the rotary cylinder; a feeding hole and a flue gas outlet are respectively formed in two ends of the preheating cylinder; a dust screen is wound on the outer side of the spiral teeth opposite to the flue gas outlet; the feeding mechanism is provided with a storage barrel communicated with the feeding hole; the heating mechanism is composed of a heating burner and a radiant tube arranged outside the heating burner in a sleeving mode, a flue gas channel is arranged between the radiant tube and the heating burner, and the flue gas channel extends out of the fixed shell and is provided with a flue gas tube extending into the material storage barrel; according to the invention, the calcining efficiency and the heat utilization efficiency can be improved, and the quality of the calcined product is improved.

Description

Technical Field

[0001] The invention relates to the technical field of rotary kilns, and in particular to a high-efficiency rotary kiln for calcining barite. Background Art

[0002] Barite calcination is an important ore processing process, which aims to improve the purity of the ore or change its physical and chemical properties through high-temperature treatment to meet different industrial needs. The calcination process of barite usually requires the barite to be processed into small particles in advance and sent to the calcination kiln. The small particles of barite are calcined at high temperature in the calcination kiln, so that the components such as barium sulfate in the barite will undergo chemical reactions to generate the desired products or intermediates. At present, the rotary kiln is commonly used for calcining barite. It has the advantages of being suitable for large-scale production, strong adaptability to raw materials, uniform calcination quality, and long service life. The rotary kiln rotates the drum as the material moves. The uniform rolling forward method makes the material heated evenly, thereby improving the quality of the barite product obtained by calcination. However, in the crushing process of barite before calcination, small particles of barite will inevitably be mixed with dust-like and other smaller barite particles, resulting in uneven particle size of the calcined barite. The calcination time of barite in a rotary kiln is relatively constant, which easily leads to overburning of smaller particle size barite after calcination. In order to optimize the calcination effect and improve product quality, the barite is usually screened more strictly and calcined separately, but this will increase the complexity of the processing technology, reduce processing efficiency and increase processing costs.

[0003] Based on the above situation, announcement number CN211903705U discloses a continuous electric heating rotary furnace, including a furnace tube part with a furnace heating zone inside, a furnace tube transmission device, a feeding device connected to the feed end of the furnace tube part, an outlet sealing bin connected to the discharge end of the furnace tube part, and a dustproof sealing component arranged between the feed end of the furnace tube part and the feeding device and between the discharge end and the outlet sealing bin; the dustproof sealing component includes: a sealing ring, a clamping mechanism, and a docking ring, the sealing ring is fixed at the feed end and the discharge end of the furnace tube part, one end of the sealing ring has a graphite ring, the docking ring is connected to the feeding device and one end of the outlet sealing bin through an expansion compensator, the end face of the docking ring is in contact with the end face of the graphite ring, the clamping mechanism is used to press the docking ring and the graphite ring against each other, and the clamping mechanism can be equivalent to the rotation of the sealing ring or the docking ring.

[0004] The above-mentioned rotary kiln is mainly used for continuous high-temperature calcination of powder materials. A dynamic sealing structure is arranged at the inlet and outlet ends to eliminate dust and overflow of combustion tail gas generated by the gaps at the joints between the two ends of the furnace tube and the front and rear fixed covers. It is particularly suitable for the calcination of particulate powder materials. However, when the rotary kiln calcines materials with uneven particle sizes, since the materials are calcined in the rotary kiln for a relatively close time, it is difficult to avoid excessive calcination of materials with smaller particle sizes, affecting the quality of the calcined products. Therefore, there is still room for improvement. Summary of the invention

[0005] In view of the technical defects existing in the background technology, the present invention proposes an efficient rotary kiln for calcining barite, which solves the above technical problems and meets the actual needs. The specific technical solution is as follows: A high-efficiency rotary kiln for calcining barite, comprising a fixed shell, a rotary drum, a preheating drum, a feeding mechanism, and a heating mechanism, wherein the fixed shell and the end of the rotary drum are movably connected to each other, the interior of the rotary drum is hollow to form a calcining chamber, the calcining chamber is provided with a calcining outlet at one end close to the fixed shell, and a calcining inlet at the other end, the outer surface of the rotary drum is provided with spiral teeth extending along a spiral and a plurality of material scooping plates extending along an axial direction, the spiral direction of the spiral teeth is the same as the rotation direction of the rotary drum, the material scooping plate is provided with a scooping groove whose opening direction matches the rotation direction of the rotary drum, and a preheating channel is provided between the material scooping plate and the outer surface of the rotary drum; The preheating cylinder is sleeved on the outer surface of the rotary cylinder, and there is a gap between the spiral teeth, the material lifting plate and the inner wall of the preheating cylinder to allow the rotary cylinder to rotate. The end of the preheating cylinder close to the calcination inlet is connected to the calcination chamber, and the surface of the end of the preheating cylinder close to the calcination outlet is provided with a feed inlet, and the surface of the other end is provided with a flue gas outlet. A dust screen is wound around the outer side of the spiral teeth relative to the flue gas outlet. The feeding mechanism is provided with at least one material storage barrel connected with the feeding port; the heating mechanism is fixedly connected with the fixed shell and extends into the calcining chamber, the heating mechanism is composed of a heating burner and a radiation tube sleeved outside the heating burner, the radiation tube extends toward the calcining inlet and the extended end forms a closed end, a flue gas channel is provided between the radiation tube and the heating burner, the flue gas channel extends outside the fixed shell and is provided with a flue gas pipe extending into the material storage barrel.

[0006] As a further technical solution of the present invention, the opening of the material slitting trough is inclined toward the inner wall of the preheating cylinder, and the opening angle of the material slitting trough is 90°-180°.

[0007] As a further technical solution of the present invention, a driving motor is provided on one side of the rotating drum, a driving gear is provided on the driving end of the driving motor, and a driven gear matching the driving gear is provided on the surface of the rotating drum.

[0008] As a further technical solution of the present invention, a feed port matching the calcination outlet is provided at the bottom of the fixed shell, a feed hopper matching the feed port is provided at the bottom of the fixed shell, and an exhaust port is provided at the top of the fixed shell.

[0009] As a further technical solution of the present invention, a material guide plate is provided at one end of the inner side of the preheating cylinder close to the calcination inlet, and the material guide plate is inclined from top to bottom close to the calcination inlet and gradually extends into the calcination chamber.

[0010] As a further technical solution of the present invention, a three-way valve is provided at the extended end of the smoke pipe, and both output ends of the three-way valve are provided with smoke branch pipes. Two smoke storage barrels are provided, and the two smoke branch pipes extend into the two storage barrels respectively, and the openings of the smoke branch pipes face the feed port.

[0011] As a further technical solution of the present invention, a feed pipe matching the feed port is provided on the top of the preheating cylinder, and two feed branch pipes respectively connected to the two storage cylinders are provided on the top of the feed pipe, and a control valve penetrating into the interior is provided on the surface of the feed branch pipe.

[0012] As a further technical solution of the present invention, a sealing ring is provided on the inner side of the fixed shell and the inner side of the end of the preheating cylinder close to the calcination outlet, and the inner side of the sealing ring abuts against the outer surface of the rotating cylinder.

[0013] As a further technical solution of the present invention, the inner diameter of the calcining chamber on one side close to the calcining outlet gradually increases and forms a material discharge slope.

[0014] As a further technical solution of the present invention, the heating burner includes the following structure: an air duct extending along the radiation tube, wherein the air duct is provided with a flame inner tube at one end close to the closed end, and an air inlet extending to the outside of the radiation tube at the other end, and a gas pipe and an ignition electrode are provided in the air duct, both extending to the flame inner tube.

[0015] The beneficial effects of the present invention are: The present invention recovers the flue gas generated after the combustion of the heating burner and mixes it with the crushed barite, so that the barite is preheated by heat exchange with the flue gas between the rotary drum and the preheating drum. The preheated barite can reduce its calcination time in the calcination chamber, and can improve the calcination efficiency and heat utilization efficiency. In addition, the barite is gradually transmitted between the rotary drum and the preheating drum through the cooperation of the spiral teeth and the shoveling plate, so that the barite can fully exchange heat with the flue gas, and the barite with a small particle size can be quickly transported into the calcination chamber during the flow of the flue gas, so as to reduce the preheating temperature of the barite with a small particle size, so that the barite with different particle sizes can achieve a closer calcination effect, and improve the quality of the calcined product. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A cross-sectional view of a high-efficiency rotary kiln for calcining barite.

[0017] Figure 2 It is a structural schematic diagram of a high-efficiency rotary kiln used for calcining barite.

[0018] Figure 3 yes Figure 1 Sectional view of AA.

[0019] Figure 4 yes Figure 1 Partial schematic diagram of point B in the middle.

[0020] Figure 5 yes Figure 1 Partial schematic diagram of point C in the middle.

[0021] Figure 6 It is a cross-sectional view of the heating mechanism of a high-efficiency rotary kiln for calcining barite.

[0022] Among them: fixed shell 1, discharge port 11, discharge hopper 12, exhaust port 13, rotary drum 2, calcining chamber 21, calcining outlet 22, calcining inlet 23, spiral teeth 24, material copying plate 25, copying trough 251, preheating channel 26, dust screen 27, driven gear 28, discharge slope 29, preheating cylinder 3, feed port 31, flue gas outlet 32, guide plate 33, feed mechanism 4, storage cylinder 41, feed pipe 42, feed branch pipe 421, control valve 43, heating mechanism 5, heating burner 51, radiation tube 52, closed end 521, flue gas channel 522, flue gas pipe 53, flue gas branch pipe 531, three-way valve 54, air duct 55, air inlet 56, flame inner tube 57, gas pipe 58, ignition electrode 59, drive motor 6, drive gear 61, sealing ring 7. DETAILED DESCRIPTION

[0023] The implementation modes of the present invention are described below in conjunction with the accompanying drawings and relevant embodiments. The implementation modes of the present invention are not limited to the following embodiments, and the present invention relates to relevant necessary components in the technical field, which should be regarded as the known technology in the technical field and can be known and mastered by the technical personnel in the technical field.

[0024] like Figure 1-3As shown, a high-efficiency rotary kiln for calcining barite comprises a fixed shell 1, a rotary drum 2, a preheating drum 3, a feeding mechanism 4, and a heating mechanism 5. The fixed shell 1 and the ends of the rotary drum 2 are movably connected to each other. The interior of the rotary drum 2 is hollow to form a calcining chamber 21. The calcining chamber 21 is provided with a calcining outlet 22 at one end close to the fixed shell 1, and a calcining inlet 23 at the other end. The outer surface of the rotary drum 2 is provided with spiral teeth 24 extending along a spiral and a plurality of material scooping plates 25 extending along an axial direction. The spiral direction of the spiral teeth 24 is the same as the rotation direction of the rotary drum 2. The material scooping plate 25 is provided with a scooping groove 251 whose opening direction matches the rotation direction of the rotary drum 2. A preheating channel 26 is provided between the material scooping plate 25 and the outer surface of the rotary drum 2. The preheating cylinder 3 is sleeved on the outer surface of the rotary cylinder 2. There is a gap between the spiral teeth 24, the material lifting plate 25 and the inner wall of the preheating cylinder 3 to allow the rotary cylinder 2 to rotate. The end of the preheating cylinder 3 close to the calcination inlet 23 is connected to the calcination chamber 21. The surface of the end of the preheating cylinder 3 close to the calcination outlet 22 is provided with a feed inlet 31, and the surface of the other end is provided with a smoke outlet 32. A dust screen 27 is wound around the outer side of the spiral teeth 24 relative to the smoke outlet 32. The feeding mechanism 4 is provided with at least one storage barrel 41 connected with the feeding port 31; the heating mechanism 5 is fixedly connected with the fixed shell 1 and extends into the calcining chamber 21, the heating mechanism 5 is composed of a heating burner 51 and a radiation tube 52 sleeved outside the heating burner 51, the radiation tube 52 extends toward the calcining inlet 23 and the extended end forms a closed end 521, a flue gas channel 522 is provided between the radiation tube 52 and the heating burner 51, the flue gas channel 522 extends to the outside of the fixed shell 1 and is provided with a flue gas pipe 53 extending into the storage barrel 41.

[0025] First of all, in order to more clearly show the structure of the present invention, Figure 2 Attach Figure 1 Based on Figure 2 This is a view without cutting the rotary drum 2.

[0026] The rotary kiln of the present invention is mainly used for calcining the crushed barite, and can also be used for calcining other granular materials. In the rotary kiln of the present invention, the fixed shell 1 and the rotary drum 2 are used as the basic structure. The fixed shell 1 is fixed in the calcining workshop by a fixed bracket and other structures. The inner wall of the rotary drum 2 is evenly paved with heat-resistant bricks to form a calcining chamber 21. One side of the rotary drum 2 is rotated by the cooperation of a driving device such as a motor and a transmission structure such as a chain and a sprocket, and the fixed shell 1 and the rotary drum 2 are movably connected by coaxial nesting. Then, the fixed shell 1 remains fixed while the rotary drum 2 rotates along its own axis. After the fixed shell 1 and the rotary drum 2 are installed and fixed, they are tilted upward from the fixed shell 1 to the rotary drum 2. Barite and other materials enter the calcination chamber 21 from the calcination inlet 23 and are calcined by the heat generated by the heating mechanism 5. The rotary drum 2 rotates to evenly heat the materials and gradually moves them to the side of the calcination outlet 22. When the materials leave the calcination chamber 21 from the calcination outlet 22, the calcination process is completed. The calcined materials can be transmitted by equipment such as conveyor belts.

[0027] The fixed shell 1 and the rotary drum 2 are the basic structures for calcining materials in the present invention. The other structures of the present invention are described below. The feeding mechanism 4 is provided with a material inlet at the top of the storage barrel 41 to allow materials to enter the interior. The crushed barite and other materials are alternately transmitted from the material inlet to the storage barrel 41 through a conveying device such as a conveyor belt. Finally, the material leaves the storage barrel 41 and enters between the preheating barrel 3 and the rotary drum 2 from the feeding port 31; the heating mechanism 5 is used to mix the fuel such as gas and the combustion-supporting air through the heating burner 51 to burn, and the flue gas generated after the combustion is radiated to the calcining chamber 21 through the radiation tube 52 in the flue gas channel 522 to achieve heat The material is calcined, and the flue gas that has completed heat radiation is transported to the storage barrel 41 through the flue gas pipe 53 to mix with the material and enters between the preheating barrel 3 and the rotary barrel 2 from the feed port 31; the preheating barrel 3, a preheating chamber is formed between the preheating barrel 3 and the rotary barrel 2, and the flue gas that has completed heat radiation still carries a certain amount of heat. The material is preheated in the preheating chamber by heat exchange with the flue gas, and the preheated material enters the calcining chamber 21 from the calcining inlet 23 for calcination; the present invention can improve energy utilization by recovering the waste heat in the flue gas to preheat the material, and the material is heated to a certain temperature after preheating, which can reduce the calcination time of the material in the calcination chamber 21 and improve the calcination efficiency.

[0028] After adopting the above structure, it should be explained that the principle of preheating the material in the preheating chamber is as follows: after the material enters the preheating chamber, it tends to gather at the bottom under the action of gravity. Since the opening of the material shoveling trough 251 is in the same direction as the rotation of the rotary drum 2, the rotary drum 2 will drive the material shoveling plate 25 to rotate synchronously to load the material at the bottom of the preheating chamber into the material shoveling trough 251 and gradually transport it to the top of the preheating chamber. The material transported to the top of the preheating chamber will slide to the bottom of the preheating chamber along the spiral teeth 24. At the same time, since the spiral direction of the spiral teeth 24 is the same as the rotation direction of the rotary drum 2, the preheating chamber can be regarded as being spirally rotated. The spiral teeth 24 are divided into a number of spaces gradually extending toward the calcining inlet 23. During the rotation of the rotary drum 2, the material in the preheating chamber is gradually transported from the side close to the feed inlet 31 to the calcining inlet 23 through the material lifting plate 25. The material transportation path direction is the same as the spiral direction of the spiral teeth 24. At the same time, the flue gas will also flow along the spiral direction of the spiral teeth 24 inside the preheating chamber. The preheating channel 26 can ensure the flow of the flue gas. The flue gas flows in the preheating chamber and contacts with the material to achieve heat exchange, thereby preheating the material. The flue gas that has completed the preheating of the material is discharged from the flue gas outlet 32.

[0029] It should be noted that materials such as barite are usually crushed by jaw crushers and other equipment. The materials obtained by the crushing process will have uneven particle sizes, and there will even be small-sized materials that are dust-like or nearly dust-like. These small-sized materials will be lifted up by the flue gas flow in the preheating chamber and flow with the flue gas, so that the flue gas can quickly transport the small-sized materials along the spiral teeth 24 to the calcination inlet 23, thereby reducing the transportation time of small-sized materials in the preheating chamber, that is, reducing the preheating time and preheating temperature, so that small-sized materials enter the calcining chamber 21 at a lower temperature, and larger-sized materials are preheated in the preheating chamber for a longer time and are preheated to a higher temperature before entering the calcining chamber 21. During the calcination process of the materials in the calcining chamber 21, the same calcination time is used to achieve a closer calcination effect between materials of different particle sizes, thereby improving the quality of the calcined products.

[0030] It should be further explained that the dust screen 27 is arranged near the inner wall of the preheating cylinder 3, and a gap is provided between the dust screen 27 and the preheating cylinder 3 to allow the rotary cylinder 2 to rotate. The dust screen 27 will rotate synchronously with the spiral teeth 24. When the flue gas and small particles move to the flue gas outlet 32, the small particles will be blocked by the dust screen 27 and cannot enter the flue gas outlet 32. Although negative pressure will be generated when the flue gas leaves the flue gas outlet 32 ​​to adsorb the small particles on the surface of the dust screen 27, as the rotary cylinder 2 rotates, the small particles adsorbed on the surface of the dust screen 27 will leave the range of the flue gas outlet 32 ​​and will fall to the bottom of the preheating chamber under the action of gravity. Then the back material lifting plate 25 cooperates with the spiral teeth 24 to transport them to the calcination inlet 23.

[0031] like Figure 1-3 As shown, as one of the preferred embodiments of the present invention, the opening of the material shoveling trough 251 is inclined toward the inner wall of the preheating cylinder 3, and the opening angle of the material shoveling trough 251 is 90°-180°; the opening angle of the material shoveling trough 251 is preferably 135°. The material shoveling trough 251 with this structure can ensure that the material inside is better accommodated, and after the material shoveling plate 25 rotates to the top of the preheating chamber, the material inside the material shoveling trough 251 gradually pours downward from the opening, which is conducive to the transmission of the material toward the calcination inlet 23.

[0032] like Figure 1 , 2 As shown, as one of the preferred embodiments of the present invention, a driving motor 6 is provided on one side of the rotating drum 2, a driving gear 61 is provided at the driving end of the driving motor 6, and a driven gear 28 matching the driving gear 61 is provided on the surface of the rotating drum 2; the driving motor 6 serves as a driving structure for the rotation of the rotating drum 2, and the driving motor 6 can drive the driving gear 61 to rotate and make the driven gear 28 rotate synchronously through meshing transmission, so as to realize the rotation of the rotating drum 2 along its own axis, and the driving gear 61 and the driven gear 28 serve as a transmission structure, and based on the gear transmission principle, the transmission structure has a longer service life, higher transmission efficiency and better controllability.

[0033] like Figure 1 , 2 As shown, as one of the preferred embodiments of the present invention, a discharge port 11 matching the calcination outlet 22 is provided at the bottom of the fixed shell 1. After the material is calcined in the calcination chamber 21, it is discharged from the rotary kiln through the discharge port 11. A conveyor belt and other equipment can be set at the bottom of the discharge port 11 to transport the calcined material. A discharge hopper 12 matching the discharge port 11 is provided at the bottom of the fixed shell 1. The discharge hopper 12 guides the material through a structure in which the inner diameter gradually decreases from top to bottom, so that the material can slide down more smoothly; an exhaust port 13 is provided at the top of the fixed shell 1. The exhaust port 13 is used to discharge the gas generated during the calcination of the material. The gas can be collected at the exhaust port 13 by setting a gas pipeline, and then discharged after treatment, thereby improving environmental protection.

[0034] like Figure 1 , 2 As shown, as one of the preferred embodiments of the present invention, a material guide plate 33 is provided at one end of the inner side of the preheating cylinder 3 near the calcination inlet 23, and the material guide plate 33 is inclined from top to bottom near the calcination inlet 23 and gradually extends into the calcination chamber 21; when the material is transported to the calcination inlet 23 through the spiral teeth 24 and the material lifting plate 25, the material will fall downward from the top of the preheating chamber to the inclined side of the material guide plate 33, and the material will be guided into the calcination chamber 21 for calcination through the material guide plate 33.

[0035] like Figure 1 , 2As shown, as one of the preferred embodiments of the present invention, a three-way valve 54 is provided at the extended end of the smoke pipe 53, and both output ends of the three-way valve 54 are provided with smoke branch pipes 531. Two storage barrels 41 are provided, and a gate for controlling the opening or closing of the material inlet is provided at the top of the storage barrel 41. The two smoke branch pipes 531 extend into the two storage barrels 41 respectively, and the openings of the smoke branch pipes 531 face the feed port 31; a feed pipe 42 matching the feed port 31 is provided at the top of the preheating barrel 3, and two feed branch pipes 421 respectively connected to the two storage barrels 41 are provided at the top of the feed pipe 42, and a control valve 43 penetrating into the interior is provided on the surface of the feed branch pipe 421.

[0036] After adopting the above structure, the crushed materials are alternately transported to the two storage barrels 41, and the two storage barrels 41 alternately guide the internal materials to the feed port 31 through the feed branch pipe 421 and the feed pipe 42. Whether the materials in the storage barrel 41 enter the preheating chamber for preheating is determined by the control valve 43 in the corresponding feed branch pipe 421. When one of the control valves 43 is opened to guide the materials in the corresponding storage barrel 41 to the preheating chamber, the flue gas passes through the three-way valve 54 along the flue gas branch pipe 531 connected to the storage barrel 41 and enters the storage barrel 41 to mix with the materials, and the gate at the top of the storage barrel 41 needs to be closed to prevent the flue gas from leaking from the material inlet at the top of the storage barrel 41 and raising dust. The materials are alternately placed down by the two storage barrels 41 and mixed with the flue gas, so that the materials can enter the preheating chamber for preheating uninterruptedly, thereby improving the efficiency of material preheating.

[0037] like Figure 1 , 4 As shown in Figure 5, as one of the preferred embodiments of the present invention, a sealing ring 7 is provided on the inner side of the fixed shell 1 and the inner side of the end of the preheating cylinder 3 close to the calcining outlet 22, and the inner side of the sealing ring 7 abuts against the outer surface of the rotary drum 2; the sealing ring 7 can improve the sealing performance of the connection between the fixed shell 1 and the rotary drum 2, and can also improve the sealing performance of the connection between the preheating cylinder 3 and the rotary drum 2, to prevent materials from entering the connection between the fixed shell 1 and the rotary drum 2 or the connection between the preheating cylinder 3 and the rotary drum 2 and affecting the normal rotation of the rotary drum 2, so that the rotary drum 2 can rotate smoothly.

[0038] like Figure 1 , 2 As shown, as one of the preferred embodiments of the present invention, the inner diameter of the calcining chamber 21 on the side close to the calcining outlet 22 gradually increases and forms a material discharge slope 29. The material discharge slope 29 can make the material close to the calcining outlet 22 leave the calcining chamber 21 more smoothly, avoid the material from piling up near the calcining outlet 22 and affecting the calcining effect, thereby improving the quality of the calcined product.

[0039] like Figure 1 , 26, as one of the preferred embodiments of the present invention, the heating burner 51 includes the following structure: an air duct 55 extending along the radiation tube 52, an end of the air duct 55 close to the closed end 521 is provided with a flame inner tube 57, and the other end is provided with an air inlet 56 extending to the outside of the radiation tube 52, and the air duct 55 is provided with a gas pipe 58 and an ignition electrode 59 both extending to the flame inner tube 57; the heating mechanism 5 of the present invention adopts the structure of a radiation tube burner, the heating burner 51 guides the combustion-supporting air into the air duct 55 through the air inlet 56, and then flows to the intersection of the flame inner tube 57 and the air duct 55, and passes the gas pipe 58 to the combustion-supporting air. The fuel gas is guided to the intersection of the flame inner tube 57 and the air duct 55, so that the fuel gas is mixed with the combustion-supporting gas and ignited through the ignition electrode 59 for combustion. During the combustion process, a flame is formed in the flame inner tube 57, and the smoke generated by the flame passes through the closed end 521 and enters the smoke channel 522. The smoke radiates heat outward in the smoke channel 522, thereby calcining the material in the calcination chamber 21. The radiation tube 52 can evenly radiate the heat in the smoke into the calcination chamber 21, so that the material is evenly heated, thereby improving the calcination effect. The smoke can also be better collected and used to preheat the material, thereby improving the heat utilization efficiency.

[0040] To sum up, the present invention recycles the flue gas generated after the combustion of the heating burner 51 and mixes it with the crushed barite, so that the barite is preheated by heat exchange with the flue gas between the rotary drum 2 and the preheating drum 3. The preheated barite can reduce its calcination time in the calcination chamber 21, and can improve the calcination efficiency and heat utilization efficiency. In addition, the barite is gradually transmitted between the rotary drum 2 and the preheating drum 3 through the spiral teeth 24 and the material lifting plate 25, so that the barite can fully exchange heat with the flue gas, and during the flow of the flue gas, the small-particle barite will be quickly transported to the calcination chamber 21, thereby reducing the preheating temperature of the small-particle barite, so that barite of different particle sizes can achieve a closer calcination effect, and the quality of the calcined product is improved.

[0041] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A high-efficiency rotary kiln for calcining barite, comprising a fixed shell (1), a rotary drum (2), a preheating drum (3), a feeding mechanism (4), and a heating mechanism (5), characterized in that: The fixed shell (1) and the end of the rotary drum (2) are movably connected to each other. The interior of the rotary drum (2) is hollow to form a calcining chamber (21). The calcining chamber (21) is provided with a calcining outlet (22) at one end close to the fixed shell (1), and a calcining inlet (23) at the other end. The outer surface of the rotary drum (2) is provided with spiral teeth (24) extending along a spiral direction and a plurality of material lifting plates (25) extending along an axial direction. The spiral direction of the spiral teeth (24) is the same as the rotation direction of the rotary drum (2). The material lifting plate (25) is provided with a material lifting groove (251) whose opening direction matches the rotation direction of the rotary drum (2). A preheating channel (26) is provided between the material lifting plate (25) and the outer surface of the rotary drum (2); The preheating cylinder (3) is sleeved on the outer surface of the rotary cylinder (2); a gap is provided between the spiral teeth (24), the material lifting plate (25) and the inner wall of the preheating cylinder (3) to allow the rotary cylinder (2) to rotate; one end of the preheating cylinder (3) close to the calcination inlet (23) is connected to the calcination chamber (21); a feed inlet (31) is provided on one end surface of the preheating cylinder (3) close to the calcination outlet (22), and a smoke outlet (32) is provided on the other end surface; a dust screen (27) is provided around the outer side of the spiral teeth (24) at a position relative to the smoke outlet (32); The feeding mechanism (4) is provided with at least one material storage barrel (41) connected to the feeding port (31); the heating mechanism (5) is fixedly connected to the fixed shell (1) and extends into the calcining chamber (21); the heating mechanism (5) is composed of a heating burner (51) and a radiation tube (52) sleeved outside the heating burner (51); the radiation tube (52) extends toward the calcining inlet (23) and the extended end forms a closed end (521); a flue gas channel (522) is provided between the radiation tube (52) and the heating burner (51); the flue gas channel (522) extends outside the fixed shell (1) and is provided with a flue gas pipe (53) extending into the material storage barrel (41).

2. The high-efficiency rotary kiln for calcining barite according to claim 1, characterized in that, The opening of the material slitting trough (251) is inclined toward the inner wall of the preheating cylinder (3), and the opening angle of the material slitting trough (251) is 90°-180°.

3. The high-efficiency rotary kiln for calcining barite according to claim 1, characterized in that, A driving motor (6) is provided on one side of the rotating drum (2), a driving end of the driving motor (6) is provided with a driving gear (61), and a driven gear (28) matching the driving gear (61) is provided on the surface of the rotating drum (2).

4. The high-efficiency rotary kiln for calcining barite according to claim 1, characterized in that, The bottom of the fixed shell (1) is provided with a discharge port (11) matching the calcination outlet (22); the bottom of the fixed shell (1) is provided with a discharge hopper (12) matching the discharge port (11); and the top of the fixed shell (1) is provided with an exhaust port (13).

5. The high-efficiency rotary kiln for calcining barite according to claim 1, characterized in that: A material guide plate (33) is provided at one end of the inner side of the preheating cylinder (3) close to the calcination inlet (23); the material guide plate (33) is inclined from top to bottom on the side close to the calcination inlet (23) and gradually extends into the calcination chamber (21).

6. The high-efficiency rotary kiln for calcining barite according to claim 1, characterized in that: A three-way valve (54) is provided at the extended end of the smoke pipe (53), and both output ends of the three-way valve (54) are provided with smoke branch pipes (531). The material storage barrel (41) is provided with two smoke branch pipes (531), and the two smoke branch pipes (531) extend into the two material storage barrels (41) respectively, and the openings of the smoke branch pipes (531) face the feed port (31).

7. The high-efficiency rotary kiln for calcining barite according to claim 6, characterized in that: A feed pipe (42) matching the feed port (31) is provided at the top of the preheating cylinder (3), two feed branch pipes (421) respectively connected to the two storage cylinders (41) are provided at the top of the feed pipe (42), and a control valve (43) penetrating into the inside is provided on the surface of the feed branch pipe (421).

8. The high-efficiency rotary kiln for calcining barite according to claim 1, characterized in that: A sealing ring (7) is provided on the inner side of the fixed shell (1) and on the inner side of one end of the preheating cylinder (3) close to the calcining outlet (22), and the inner side of the sealing ring (7) abuts against the outer surface of the rotating cylinder (2).

9. The high-efficiency rotary kiln for calcining barite according to claim 1, characterized in that: The inner diameter of the calcining chamber (21) on the side close to the calcining outlet (22) gradually increases and forms a material discharge slope (29).

10. The high-efficiency rotary kiln for calcining barite according to claim 1, characterized in that: The heating burner (51) comprises the following structure: an air duct (55) extending along the radiation tube (52); a flame inner tube (57) is provided at one end of the air duct (55) close to the closed end (521); an air inlet (56) extending to the outside of the radiation tube (52) is provided at the other end; a gas pipe (58) and an ignition electrode (59) are provided in the air duct (55), both of which extend to the flame inner tube (57).

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