A continuous granulation apparatus and process

Abstract

The present application relates to a kind of rotary kiln continuous granulation device and process, belong to rotary kiln granulation production technical field.The continuous granulation device includes granulation kiln, the granulation kiln includes rotary kiln body and power mechanism, the outer periphery of the rotary kiln body is provided with gear ring and the power gear of power mechanism meshing connection, the both ends of the rotary kiln body are rotatably connected with feed cover and discharge cover, and rolling device is arranged along the axis in kiln body, the rolling device includes roller, the roller is fixedly connected with the support rod of cross near both ends respectively, 4 press rolls are connected between the end of two support rods, the both ends of press roll are rotatably connected with the support rod of both sides respectively, the both ends of the roller are rotatably connected with feed cover and discharge cover by bearing, and the one end of the roller passes out rotary kiln body, and is connected power mechanism.The continuous granulation device designed in the present application can realize the continuous granulation production of material, and production efficiency is high, energy consumption is low.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of granulating material production, in particular to a rotary kiln continuous granulating device and its production process. BACKGROUND

[0002] In the production of granulating materials, granulation is a key process to improve the flowability, bulk density and processability of materials, and is widely used in the fields of chemical industry, metallurgy, medicine, food and others. The traditional granulation process mainly uses batch reaction kettles or mixing granulators to realize particle formation through mechanical stirring or spraying. However, such devices have obvious limitations: first, batch operation leads to low production efficiency, making it difficult to meet the needs of large-scale continuous production; second, the unit processing capacity of the device is limited, energy consumption is high, and frequent start-stop is required, increasing operating costs; third, the uniformity of material mixing and shear force are insufficient, which can easily cause problems such as loose particles and low tap density, affecting subsequent application performance.

[0003] In recent years, rotary kiln granulation technology has gradually attracted attention due to its advantages in continuous production. In the prior art, rotary kilns usually improve the mixing effect of materials by setting lifting plates or scoops on the inner wall of the kiln body. For example, patent CN114485090A provides a new rotary furnace lifting and folding layout structure, which includes a rotary furnace tube, a first lifting structure, a second lifting structure, a first baffle, a second baffle and a guide plate. The lifting structure is F-shaped and is arranged in a staggered manner to improve the dispersibility and contact efficiency of the material in a wave-shaped folding rotation manner. Patent CN117534063A reports a battery graphite-based negative material coating granulation rotary kiln. In the coating and granulation section, the heat provided by the heating furnace is precisely controlled, combined with the scoops welded on the inner wall of the rotary cylinder, so that the material undergoes different material chemical changes at different temperature sections. However, the granulating components in the above patents mainly realize granulation by lifting and scooping plates welded on the cylinder wall, which are limited by the rotation speed of the cylinder. The shear rate between the scooping plate and the material is low, and the shear force is weak, resulting in problems such as loose particles and low tap density of the granulated products. In addition, the inner wall of such a granulating kiln is prone to adhering material, which needs to be cleaned frequently during long-term operation, affecting production efficiency.

[0004] Therefore, it is an urgent need in the field of granulating material processing to develop a granulating device that has high-efficiency mixing, strong shear force, low energy consumption and is suitable for continuous production. SUMMARY

[0005] To solve the problems in the prior art, the present application designs a rotary kiln continuous granulating device to solve the problems of high energy consumption, low production efficiency, poor shear effect on materials, loose particles and low tap density of the produced particles in the existing reaction kettle type granulating device.

[0006] The technical scheme adopted by the present application is: the continuous granulating device comprises a granulating kiln, the granulating kiln comprises a rotary kiln body and a power mechanism, a gear ring is arranged on the outer periphery of the rotary kiln body and is in meshing connection with the power gear of the power mechanism, feed covers and discharge covers are rotatably connected to the two ends of the rotary kiln body respectively, a rolling device is arranged along the axis in the kiln body, the rolling device comprises a rolling shaft, cross-shaped support rods are fixedly connected to the two ends of the rolling shaft respectively, four pressure rollers are connected between the end portions of the two support rods, the two ends of the pressure rollers are rotatably connected with the support rods on the two sides respectively, the two ends of the rolling shaft are rotatably connected with the feed covers and the discharge covers through bearings, and one end of the rolling shaft penetrates through the rotary kiln body and is connected with the power mechanism.

[0007] Further, the pressure roller comprises a main shaft, four wing plates are welded on the main shaft in a cross shape along the length direction, and an arc-shaped pressing plate is perpendicularly welded at the top end of each wing plate; and the two ends of the main shaft are rotatably connected with the support rods.

[0008] Further, in the rolling process, the four pressure rollers are in contact with the inner wall of the rotary kiln body.

[0009] Further, front and rear gear rings are arranged on the outer periphery of the rotary kiln body near the two ends respectively, the rear gear ring is in meshing connection with the power gear of the power mechanism, the front gear ring is in meshing connection with a first transmission gear, a second transmission gear is connected with the first transmission gear through a transmission shaft at the axis center of the first transmission gear, the front end of the rolling shaft penetrates through the rotary kiln body from one end of the feed cover, a third transmission gear is fixedly connected to the penetrating end, the second transmission gear is connected with the third transmission gear through a chain, so as to drive the rolling device to rotate, and the diameters of the first transmission gear, the second transmission gear and the third transmission gear decrease in sequence.

[0010] Further, the continuous granulating device further comprises a preheating kiln and a cooling kiln, the discharge end of the preheating kiln is in butt joint with the feeding end of the granulating kiln, and the discharge end of the granulating kiln is in butt joint with the feeding end of the cooling kiln.

[0011] Further, three-stage heating zones are arranged in the kiln body of the granulating kiln in sequence, and at least one heating zone is arranged in the kiln body of the preheating kiln.

[0012] Further, a cooling jacket is rotatably connected to the outer side of the kiln body of the cooling kiln, a row of cooling water nozzles is arranged above the kiln body of the cooling kiln on the upper side of the cooling jacket, the cooling water nozzles are connected with the water outlet end of a circulating cooling water system through pipelines, a water outlet is formed in the bottom of the cooling jacket, and the water outlet is connected with the water return end of the circulating cooling water system through pipelines.

[0013] Further, the continuous granulating device further comprises a protective gas system, the protective gas system comprises a protective gas source, the protective gas source is respectively connected with the air inlet end of the preheating kiln, the granulating kiln and the cooling kiln through pipelines, and the air outlet ends of the preheating kiln, the granulating kiln and the cooling kiln are connected with the tail gas purification treatment system after pipeline convergence.

[0014] The application provides a production process of the continuous granulating device for the granulating material.

[0015] (1) preheating, the mixture of the solid binder and the primary particles of the granulating material is sent into the preheating kiln through the screw conveyor, and the mixture is heated to below the melting point of the solid binder in the preheating kiln;

[0016] (2) roll granulating, the preheated mixture is sent into the granulating kiln through the material feeding pipe, the rotary kiln body of the granulating kiln is driven to rotate by starting the driving force mechanism, so that the roller shaft of the roll pressing device is driven to rotate reversely through the front gear ring, the first transmission gear, the second transmission gear and the third transmission gear, the roller shaft drives the support rod to rotate, and the four pressure rollers also rotate, the four wing plates of each pressure roller form a material lifting effect on the mixture, and the four pressure plates extrude and vibrate the mixture; the mixture is continuously heated to above the melting point of the binder in the first heating zone and the second heating zone of the granulating kiln, the binder and the primary particles of the granulating material are fully mixed and uniformly distributed under the stirring action of the wing plates, and the secondary granulation is completed through extrusion and vibration of the pressure plates;

[0017] (3) particle roasting, the material completing the secondary granulation continues to move forward in the granulating kiln, high-temperature roasting is performed on the material in the third heating zone, and the volatile components in the material are further volatilized;

[0018] (4) cooling and discharging, the material particles completing the granulating roasting are discharged from the discharge cover of the granulating kiln and enter the cooling kiln, the spray cooling water of the cooling jacket is opened, the kiln body of the cooling kiln is cooled, the high-temperature material particles are gradually cooled through heat exchange with the kiln wall, and are discharged from the kiln tail;

[0019] (5) protective gas, during the operation of the continuous granulating device, the protective gas source respectively inputs the protective gas into the three kiln bodies through the respective air inlet ends, the tail gas formed from the three kiln bodies is discharged from the air outlet ends, is converged through the pipelines and then enters the tail gas treatment system for purification treatment.

[0020] Compared with the prior art, the continuous granulating device and the process designed in the application have the following advantages:

[0021] The continuous granulation device is composed of a preheating kiln, a granulation kiln and a cooling kiln, realizes continuous production of granulation, reduces intermittent operation during production of the traditional granulation device, reduces energy consumption and time waste, and improves production efficiency. Meanwhile, compared with the traditional horizontal kettle granulation device, the device greatly reduces the floor area and construction cost of the equipment.

[0022] The granulation kiln adopts the design of a rotary kiln body plus a rolling device. The rolling device is driven to rotate by the rotary kiln body through a front gear ring and multi-stage transmission gears. The rotating direction of the rolling device is opposite to that of the rotary kiln body. Meanwhile, the diameters of the multi-stage transmission gears are gradually reduced, which greatly increases the rotating speed of the rolling device, improves the mixing effect and shearing force of the rolling device on the materials.

[0023] The four rollers of the rolling device are provided with cross-shaped assembled fin plates and pressing plates. The rotating process plays a role of material lifting and extrusion on the granulation materials, and the materials are subjected to both shearing granulation and rolling granulation, which greatly improves the granulation strength. Meanwhile, the fin plates locally mix the materials during the rotating process, which can greatly reduce the generation of dust in the kiln body, reduce the dust content in the tail gas, and reduce the treatment cost of the tail gas.

[0024] The rolling device in the granulation kiln can clean the inner wall of the kiln body during the relative rotation with the rotary kiln body, which can effectively avoid the sticking of materials to the wall during the granulation process. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a structural schematic view of the continuous granulation device.

[0026] Figure 2 is a sectional structural schematic view of the granulation kiln.

[0027] Figure 3 is a connection structure schematic view of the kiln body and the rolling device of the granulation kiln.

[0028] Figure 4 is a structural schematic view of the rolling device.

[0029] Figure 5 is a structural schematic view of the roller.

[0030] Figure 6 is a structural schematic view of the cooling kiln.

[0031] In the diagram, 1 is the preheating kiln, 2 is the granulation kiln, 3 is the cooling kiln, 4 is the rolling device, 201 is the rotary kiln body, 202 is the feed hood, 203 is the discharge hood, 204 is the rear gear ring, 205 is the front gear ring, 206 is the rolling ring, 207 is the power mechanism, 209 is the first transmission gear, 210 is the second transmission gear ring wheel, 211 is the third transmission gear, 212 is the chain, 31 is the cooling jacket, 32 is the cooling water nozzle, 41 is the roller, 42 is the support rod, 43 is the pressure roller, 431 is the main shaft, 432 is the fin plate, and 433 is the pressure plate. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The technical solutions in the embodiments of the present invention will be clearly and completely described. The described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0033] like Figure 1 As shown, this invention patent designs one embodiment of a continuous granulation device. In this embodiment, the continuous granulation device includes a preheating kiln 1, a granulation kiln 2, and a cooling kiln 3 arranged sequentially. All three adopt a rotary kiln structure. The two ends of the kiln body are rotatably connected to inlet and outlet hoods, respectively. The inlet and outlet hoods are respectively provided with a feed inlet, an air inlet, a discharge outlet, and an air outlet. The discharge end of the preheating kiln 1 is connected to the feed end of the granulation kiln 2 via a chute, and the discharge end of the granulation kiln 2 is connected to the feed end of the cooling kiln 3. The air inlet pipes of the three kilns are connected to a protective gas source; in this embodiment, nitrogen is used as the protective gas. The air outlets of the three kilns are collected through pipelines and connected to a tail gas purification system.

[0034] Combination Figure 2 , 3 As shown in Figure 4, the granulation kiln 2 includes a rotary kiln body 201 and a power mechanism 207. A front gear ring 205 and a rear gear ring 204 are respectively provided near both ends of the outer periphery of the rotary kiln body 201, with the rear gear ring 204 meshing with the power gear of the power mechanism 207. Additionally, rolling rings 206 are also provided near both ends of the outer periphery of the kiln body for roller support, assisting in the rotation of the kiln body. A feed hood 202 and a discharge hood 203 are rotatably connected to both ends of the rotary kiln body 201, respectively. A rolling device 4 is arranged along the axis inside the kiln body. The rolling device 4 includes a roller 41, with both ends of the roller 41 being rotatably connected to the feed hood 202 and the discharge hood 203 via bearings. The front end of the roller 41 extends outward from the feed hood 202, and a third transmission gear 211 is fixedly connected to the protruding end. The part of the roller 41 located inside the kiln body is fixedly connected to the cross-shaped support rods 42 near both ends. Four pressure rollers 43 are connected between the four ends of the two support rods 42. The two ends of the pressure rollers 43 are rotatably connected to the support rods 42 on both sides.

[0035] A first transmission gear 209 is meshed with the front gear ring 205 of the rotary kiln body 201 of the granulation kiln 2. A second transmission gear 210 is connected to the shaft of the first transmission gear 209 via a forward-extending horizontal transmission shaft. The second transmission gear 210 and the third transmission gear 211 are located on the same radial direction. The second transmission gear 210 is connected to the third transmission gear 211 via a chain 212, driving the rolling device 4 to rotate. At the same time, the diameters of the first transmission gear 209, the second transmission gear 210, and the third transmission gear 211 decrease sequentially, and the three sets of gear transmissions achieve a speed regulation effect.

[0036] Combination Figure 5 As shown, the pressure roller 43 includes a main shaft 431, on which four fins 432 are welded in a cross shape along the length direction. Each fin 432 has an arc-shaped pressure plate 433 vertically welded to its top. The two ends of the main shaft 431 are rotatably connected to the support rods 42 on both sides. During rotation, the arc-shaped pressure plates 433 of the four pressure rollers 43 of the rolling device 4 will contact the inner wall of the rotary kiln body 201.

[0037] A cooling jacket 31 is rotatably connected to the outside of the kiln body of the cooling kiln 3. A row of cooling water nozzles 32 is installed on the upper side of the cooling jacket 31 above the kiln body of the cooling kiln 3. The cooling water nozzles 32 are connected to the outlet of the circulating cooling water system. The bottom of the cooling jacket 31 has an outlet, which is connected to the return end of the circulating cooling water system. The kiln body of the cooling kiln 3 is cooled by spraying.

[0038] The rotary kiln continuous granulation device disclosed in this invention patent can be applied to the continuous granulation of carbon-based materials, ceramic materials (zirconia, silicon nitride, etc.);

[0039] Taking the granulation production of carbon-based materials as an example, the specific process is as follows:

[0040] (1) Preheating: First, the mixture of solid binder and primary particles is fed into preheating kiln 1 by screw conveyor. In preheating kiln 1, the mixture is heated to below the melting point of solid binder. The primary particles in the mixture are mainly petroleum coke, needle coke, etc., with a particle size D50 of generally 8-10μm. The binder is asphalt binder, with a content of 5%-20% of the total mass of the mixture. The heating temperature of the mixture in preheating kiln 1 is below 250℃, and the heating temperature of the furnace is controlled at 400℃-500℃. The material residence time is 10-30min.

[0041] (2) Roller granulation: The preheated mixture is fed into the granulation kiln 2 through the chute. The drive mechanism is started to drive the rotary kiln body 201 of the granulation kiln 2 to rotate. This drives the roller 41 of the rolling device 4 to rotate in the opposite direction to the rotary kiln body 201 through the front gear ring 205, the first transmission gear 209, the second transmission gear 210 and the third transmission gear 211. At the same time, the roller 41 drives the support rod 42 to rotate, and the four pressure rollers 43 also rotate. During the rotation of the four pressure rollers 43, the four fins 432 of each pressure roller form a lifting effect on the mixture. Four pressure plates 433 compress the mixture. The mixture continues to be heated above the melting point of the asphalt binder in the first and second heating zones of the granulation kiln 2. Under the stirring action of the fins 432, the binder and the primary granulated material are thoroughly mixed and uniformly, and then compacted by the pressure plates 433 to complete the secondary granulation. The optimal secondary granulation temperature of the mixture is around 400-450℃, and the furnace temperature is controlled at 500-550℃. The residence time of the material in the granulation stage is generally 1-4 hours, with an optimal granulation time of 2 hours. The rotation speed of the rolling device 4 is 10-40 r / min, with an optimal speed of 30 r / min.

[0042] (3) Particle roasting: The material that has completed secondary granulation continues to move forward in the granulation kiln and is roasted at high temperature in the third heating zone. The furnace temperature in this zone is controlled at 650-700℃ to further volatilize the volatiles in the material.

[0043] (4) Cooling and discharging: The material particles that have completed granulation and roasting are discharged from the discharge hood of the granulation kiln and enter the cooling kiln. The cooling jacket is turned on to spray cooling water to cool the kiln body. The high-temperature material particles come into contact with the kiln wall to exchange heat and gradually cool down to below 60°C, and are discharged from the kiln tail.

[0044] (5) Protective gas: During the operation of the entire continuous granulation device, protective gas is supplied to the three kilns through their respective inlet ends by the protective gas source. The resulting tail gas is discharged from the outlet ends of the three kilns and then collected through pipelines before entering the tail gas treatment system for purification.

[0045] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the present invention. Any simple equivalent changes and modifications made in accordance with the claims and description of the present invention shall still fall within the scope of the present invention.

Claims

1. A continuous granulation apparatus, characterized in that, The continuous granulation device includes a granulation kiln, which includes a rotary kiln body and a power mechanism. A gear ring is provided on the outer periphery of the rotary kiln body and meshes with the power gear of the power mechanism. A feed hood and a discharge hood are rotatably connected to both ends of the rotary kiln body, respectively. A rolling device is provided along the axis inside the kiln body. The rolling device includes a roller. A cross-shaped support rod is fixedly connected to both ends of the roller. Four pressure rollers are connected between the ends of the two support rods. The two ends of the pressure rollers are rotatably connected to the support rods on both sides, respectively. The two ends of the roller are rotatably connected to the feed hood and the discharge hood through bearings, respectively. One end of the roller passes through the rotary kiln body and is connected to the power mechanism. The pressure roller includes a main shaft, on which four fins are welded in a cross shape along the length direction. Each fin has an arc-shaped pressure plate vertically welded to its top. The two ends of the main shaft are rotatably connected to a support rod. The outer periphery of the rotary kiln body is provided with a front gear ring and a rear gear ring near both ends. The rear gear ring is meshed with the power gear of the power mechanism. The front gear ring is meshed with a first transmission gear. The shaft of the first transmission gear is connected to a second transmission gear through a transmission shaft. The front end of the roller passes through the rotary kiln body from one end of the feed hood. The end of the roller is fixedly connected to a third transmission gear. The second transmission gear is connected to the third transmission gear through a chain, which drives the rolling device to rotate. The diameters of the first transmission gear, the second transmission gear and the third transmission gear decrease in sequence. The continuous granulation device further includes a preheating kiln and a cooling kiln. The discharge end of the preheating kiln is connected to the feed end of the granulation kiln, and the discharge end of the granulation kiln is connected to the feed end of the cooling kiln.

2. The continuous granulation apparatus according to claim 1, characterized in that, During the rotation of the rolling device, all four pressure rollers are spaced 2-5 cm apart from the inner wall of the rotary kiln.

3. The continuous granulation apparatus according to claim 2, characterized in that, The granulation kiln has three heating zones arranged sequentially inside its kiln body, and the preheating kiln has at least one heating zone inside its kiln body.

4. The continuous granulation apparatus according to claim 3, characterized in that, A cooling jacket is rotatably connected to the outside of the cooling kiln body. A row of cooling water nozzles is provided on the upper side of the cooling jacket above the kiln body. The cooling water nozzles are connected to the outlet of the circulating cooling water system. A water outlet is opened at the bottom of the cooling jacket, and the water outlet is connected to the return end of the circulating cooling water system.

5. A continuous granulation apparatus according to claim 4, characterized in that, The continuous granulation device also includes a protective gas system, which includes a protective gas source. The protective gas source is connected by pipelines to the inlet ends of the preheating kiln, the granulation kiln, and the cooling kiln. The outlet pipelines of the preheating kiln, the granulation kiln, and the cooling kiln are collected and connected to the tail gas purification and treatment system.

6. A production process for a continuous granulation apparatus as described in claim 5, characterized in that, The specific steps of the production process are as follows: (1) Preheating: First, the mixture of solid binder and granulated material particles is fed into the preheating kiln by a screw conveyor. In the preheating kiln, the mixture is heated to below the melting point of the solid binder. (2) Roller granulation: The preheated mixture is fed into the granulation kiln through the chute. The power mechanism is started to drive the rotary kiln body of the granulation kiln to rotate. The rollers of the roller pressing device are driven to rotate in the opposite direction to the rotary kiln body through the front gear ring, the first transmission gear, the second transmission gear and the third transmission gear. While the rollers drive the support rod to rotate, the four pressure rollers also rotate. During the rotation of the four pressure rollers, the four fins of each pressure roller form a lifting effect on the mixture, and the four pressure plates squeeze the mixture. The mixture continues to be heated in the first heating zone and the second heating zone of the granulation kiln to a temperature above the melting point of the binder. Under the stirring action of the fins, the binder and the granulated material are fully mixed and uniformly, and the secondary granulation is completed by the pressure plate squeezing and vibration. (3) Particle roasting: The material that has completed secondary granulation continues to move forward in the granulation kiln and is roasted at high temperature in the third heating zone to further volatilize the volatiles in the material. (4) Cooling and discharging: The material particles that have completed granulation and roasting are discharged from the discharge hood of the granulation kiln and enter the cooling kiln. The cooling jacket is turned on to spray cooling water to cool the kiln body. The high-temperature material particles come into contact with the kiln wall to exchange heat and gradually cool down, and are discharged from the kiln tail. (5) Protective gas: During the operation of the entire continuous granulation device, protective gas is supplied to the three kilns through their respective inlet ends by the protective gas source. The resulting tail gas is discharged from the outlet ends of the three kilns by the induced draft fan and then collected through pipelines before entering the tail gas treatment system for tail gas treatment.

Images