Hazardous waste incineration rotary kiln and rotary kiln feeding assembly

Abstract

The application discloses a hazardous waste incineration rotary kiln and a rotary kiln feeding assembly. The hazardous waste incineration rotary kiln comprises a kiln body and a kiln head cover, the kiln body is provided with a feeding channel at a kiln head, the kiln head cover is embedded into the feeding channel, a closing inclined surface is arranged on the feeding channel, and a first air inlet and a second air inlet are arranged on the kiln head cover in a tangential mode. The rotary kiln feeding assembly comprises a material pouring device, a feeding device and the hazardous waste incineration rotary kiln. The material pouring device comprises a hopper and a vibrating mechanism for overturning and discharging. The hazardous waste incineration rotary kiln and the rotary kiln feeding assembly provided by the application reduce the infection risk, the material is crushed and compacted by the feeding device and then enters the kiln body for incineration, the return of the material is reduced, the mixing of the combustion-supporting air and the material is strengthened, the material is fully burned, the pollutant removal efficiency is improved, and the problem of emission exceeding the standard is avoided.

Description

Hazardous waste incineration rotary kiln and rotary kiln feeding assembly Technical Field

[0001] This application relates to the field of rotary kiln technology, and in particular to a rotary kiln for hazardous waste incineration and a rotary kiln feeding assembly. Background Technology

[0002] Currently, the main equipment for hazardous waste incineration includes rotary kiln incinerators, mechanical grate incinerators, and fluidized bed incinerators. Among them, rotary kiln incineration technology is widely used in solid waste incineration due to its advantages such as strong adaptability to materials, ability to process solid and liquid waste of any form, low requirements on the shape of fuel entering the furnace during incineration, and no need for complex pretreatment processes.

[0003] Rotary kiln combustion is divided into three types: co-current ash and slag type, co-current melting slag type, and counter-current type. In the co-current rotary kiln, the material and flue gas move in the same direction, and the drying, combustion, and burnout sections are clearly defined. The co-current ash and slag rotary kiln offers convenient feeding, air intake, and auxiliary burner arrangement, facilitating equipment operation and maintenance and aiding in material pretreatment. Furthermore, the flue gas has a longer residence time within the kiln, resulting in more complete reactions. However, in actual operation, the co-current ash and slag rotary kiln suffers from serious problems such as material backflow and uneven material mixing leading to incomplete combustion. After being fed into the rotary kiln by the feeding mechanism, the material easily returns to the gap between the kiln head hood and the kiln body, causing an increase in the kiln's operating current, potentially leading to material backfire, flue gas overflow, and other safety and environmental incidents. In severe cases, this can cause the rotary kiln to shut down. Additionally, rotary kiln combustion requires supplemental combustion air, and the amount of combustion air added significantly affects the kiln's temperature changes, thermal efficiency, and the completeness of material combustion. Improper adjustment may result in emissions exceeding standards.

[0004] Currently, co-current ash-type hazardous waste incineration systems are designed with a discharge port at the bottom of the kiln hood to receive return material from the rotary kiln, allowing the material to be discharged through the lower discharge port and preventing the rotary kiln from shutting down. However, since the return material at the kiln hood discharge port is mostly unburned material, it may continue to burn or smolder after being discharged, posing safety and environmental risks. Currently, most rotary kilns supply combustion air directly in a direction perpendicular to the kiln hood. However, the combustion air often becomes weak after entering the kiln and fails to provide sufficient disturbance, resulting in uneven combustion within the kiln and making it difficult to control pollutant concentrations, especially CO concentrations. Summary of the Invention

[0005] The purpose of this application is to provide a hazardous waste incineration rotary kiln and rotary kiln feeding assembly, which reduces material return, enhances the mixing of combustion air and materials, ensures complete combustion of materials, improves pollutant removal efficiency, and avoids the problem of excessive emissions.

[0006] The present application provides a rotary kiln for hazardous waste incineration, comprising: a kiln body, wherein the kiln body has a feeding channel at the kiln head; a kiln head hood, wherein the kiln head hood is embedded in the feeding channel, wherein the feeding channel is provided with a tapering slope at the end of the kiln head hood, and wherein a first air inlet and a second air inlet are respectively provided on opposite sides of the kiln head hood.

[0007] Optionally, the length of the kiln head hood embedded in the feed channel is L, 40mm≤L≤100mm.

[0008] Optionally, the angle of inclination of the constricted bevel is θ, where 2°≤θ≤5°.

[0009] The present application provides a rotary kiln feeding assembly, comprising: a material tilting device, a feeding device, and any one of the above-described hazardous waste incineration rotary kilns; the material tilting device includes a hopper for tilting and unloading material and a rapping mechanism, the rapping mechanism including a rapper and a rapping controller, the rapping controller being used to control the rapper to rappel the hopper when unloading material from the hopper; the inlet of the feeding device is used to receive the material from the hopper, and the outlet of the feeding device is connected to the kiln head hood.

[0010] Optionally, the rapping controller includes a meshing drive gear and a driven gear, and a drive unit that drives the drive gear, and the rapper is connected to the driven gear via a connecting rod.

[0011] Optionally, the vibratory controller further includes a counterweight fixed on the connecting rod and an elastic element connected between the counterweight and the vibrator. When the connecting rod is rotated to a vertical position, the vibrator vibrates the bottom or side of the hopper.

[0012] Optionally, the rapping controller further includes a position sensor for emitting a position signal when the hopper is flipped to a predetermined position and a controller for controlling the drive unit. The controller is communicatively connected to the position sensor and is used to control the drive unit to disconnect the drive of the drive gear after receiving the position signal.

[0013] Optionally, the feeding device includes a lifting section and a pushing section. The lifting section is used to carry the material and can be raised and lowered. The pushing section is telescopically configured to push the material into the feeding channel when the lifting section rises to the level of the material with the feeding channel.

[0014] Optionally, the feeding device includes a shaft-type screw feeder and a shaftless screw feeder connected together. The inlet of the shaft-type screw feeder is used to receive the material discharged from the hopper, and the outlet of the shaftless screw feeder is connected to the feeding channel.

[0015] Optionally, the axial spiral feed section includes a screw and a crushing blade. The screw extends axially and is provided with spiral blades. A moving blade is provided on the outer edge of the spiral blade. The crushing blade is fixed to the outside of the moving blade and is spaced apart from the moving blade.

[0016] The above technical solution has the following beneficial effects:

[0017] The hazardous waste incineration rotary kiln and rotary kiln feeding assembly provided in this application use a vibrator to shake the waste remaining in the hopper out of the hopper without manual intervention, reducing the risk of infection. After the waste falls into the feeding equipment, it is crushed and compacted before being transported to the rotary kiln for incineration. The rotary kiln is equipped with a tapering slope to effectively prevent material backflow. The first and second air inlets are arranged opposite each other and extend tangentially, supplying air tangentially into the kiln body at a certain angle. This allows the combustion air to enter the kiln body tangentially from the kiln head hood. Through the embedded structure of the kiln head hood and the kiln head, the combustion air in the rotary kiln forms a uniform circulation, thereby increasing the wind speed and pressure entering the rotary kiln. This achieves tangential spiral entry of the combustion air into the kiln, and the Venturi effect created by the embedded structure and tapering slope forms turbulence in the kiln, enhancing the mixing of the combustion air and the material, ensuring complete combustion, improving pollutant removal efficiency, and avoiding the problem of exceeding emission standards. Attached Figure Description

[0018] Figure 1 is a cross-sectional view of a hazardous waste incineration rotary kiln in one embodiment of this application;

[0019] Figure 2 is a partial view of a hazardous waste incineration rotary kiln in one embodiment of this application;

[0020] Figure 3 is a schematic diagram of the structure of a material dumping device in one embodiment of this application;

[0021] Figure 4 is a schematic diagram of the feeding device in one embodiment of this application;

[0022] Figure 5 is a schematic diagram of the feeding device in one embodiment of this application;

[0023] Figure 6 is a schematic diagram of the shaftless screw feed section in the feeding device according to an embodiment of this application.

[0024] Attached icon number

[0025] 1-Kiln body, 10-Feeding channel, 11-Closing slope;

[0026] 2-Kiln head hood, 20-First air inlet, 21-Second air inlet;

[0027] 3-Material dumping equipment, 30-Hopper, 31-Vibrating mechanism, 32-Vibrator, 33-Driving gear, 34-Driven gear, 35-Connecting rod, 36-Counterweight, 37-Elastic component;

[0028] 4-Feeding equipment, 40-Lifting section, 41-Pushing section, 42-Shafted screw feeder, 43-Shaftless screw feeder, 44-Feeding hopper, 45-Screw, 46-Screw blade, 47-Moving knife, 48-Crushing knife. Detailed Implementation

[0029] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0030] It is readily understood that, based on the technical solution of this invention, various structural and implementation methods can be interchanged by those skilled in the art without altering the essential spirit of the invention. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative examples of the technical solution of this invention and should not be considered as the entirety of the invention or as limitations or restrictions on the technical solution of the invention.

[0031] The directional terms such as up, down, left, right, front, back, front, back, top, and bottom mentioned or possibly used in this specification are defined relative to the structures shown in the accompanying drawings. They are relative concepts and may therefore vary depending on their location and usage. Therefore, these or other directional terms should not be interpreted as restrictive.

[0032] This application provides a rotary kiln for hazardous waste incineration, comprising: a kiln body 1 and a kiln head hood 2.

[0033] Please refer to Figures 1 and 2. The kiln body 1 has a feeding channel 10 at the kiln head. The kiln head cover 2 is embedded in the feeding channel 10. The feeding channel 10 is provided with a tapering slope 11 at the end of the kiln head cover 2. The kiln head cover 2 has a first air inlet 20 and a second air inlet 21 that are tangentially arranged on opposite sides.

[0034] In this embodiment, the constricted slope 11 effectively prevents material backflow. The first air inlet 20 and the second air inlet 21, as shown in Figure 2, are arranged opposite each other and extend tangentially to supply air tangentially into the kiln body 1. This allows the combustion air to enter the kiln body 1 tangentially from the kiln head hood 2. Through the embedded structure of the kiln head hood 2 and the kiln body 1, the combustion air in the rotary kiln forms a uniform circulation, thereby increasing the wind speed and pressure entering the rotary kiln. This achieves the effect of the combustion air entering the kiln tangentially in a spiral motion. Furthermore, the Venturi effect formed by the embedded structure and the constricted slope 11 creates turbulence within the rotary kiln, enhancing the mixing of the combustion air and the material, ensuring complete combustion, improving pollutant removal efficiency, and preventing excessive emissions. Simultaneously, this application helps improve the combustion efficiency of the combustion air and reduce heat loss.

[0035] As an optional embodiment, the length of the kiln head cover 2 embedded in the feed channel 10 is L, 40mm≤L≤100mm. As shown in Figure 1, by embedding the kiln head cover 2 in the feed channel 10 at a position between 40mm and 100mm, both backflow of material and interference with the rotation of the kiln body 1 are effectively prevented.

[0036] As an optional embodiment, the inclination angle of the constricting slope 11 is θ, where 2°≤θ≤5°. In this embodiment, the refractory material at the front end of the rotary kiln is sloped to form a constricted structure at the front end of the rotary kiln, as shown in Figure 1. At the inlet portion within the feed channel 10, the refractory material is raised inward by H (50≤H≤100mm) to form a uniform diameter constriction. The inner diameter of the uniform diameter constriction is larger than the outer diameter of the embedded portion of the kiln head hood 2. It then transitions to the conventional inner diameter of the feed channel 10 in the form of a slope. The transition portion defines the constricting slope 11. The inclination angle of the constricting slope 11 is set between 2° and 5°, which can effectively prevent material backflow. Furthermore, the inclination angle of the constricting slope 11 in this application, compared to a large inclination angle of 25° or more, can effectively prevent material blockage within the feed channel 10, thus increasing the smoothness of feeding.

[0037] This application also provides a rotary kiln feeding assembly, including: a material dumping device 3, a feeding device 4, and the hazardous waste incineration rotary kiln described in any of the above embodiments.

[0038] The material dumping device 3 includes a hopper 30 for tipping and unloading material and a vibrating mechanism 31. The vibrating mechanism 31 includes a vibrator 32 and a vibrating controller. The vibrating controller is used to control the vibrator 32 to vibrate the hopper 30 when unloading material. The inlet of the feeding device 4 is used to receive the material from the hopper 30, and the outlet of the feeding device 4 is connected to the kiln head hood 2.

[0039] In this embodiment, the vibrator 32 can vibrate the bottom or side of the hopper 30. By vibrating the hopper 30 with the vibrator 32, the waste materials remaining in the hopper 30, such as some flammable, highly reactive hazardous waste, medical waste, etc., can be poured out without manual intervention, reducing the risk of infection.

[0040] In this embodiment, the waste material remaining in the hopper 30 is shaken out of the hopper 30 by the vibrator 32. After the waste material falls into the feeding device 4, it is transported to the rotary kiln for incineration. The rotary kiln is equipped with a tapering slope 11, which can effectively prevent the material from returning. The first air inlet 20 and the second air inlet 21 are arranged opposite each other and extend tangentially, supplying air tangentially into the kiln body 1 at a certain angle. This allows the combustion air to enter the kiln body 1 tangentially from the kiln head cover 2. Through the embedded structure of the kiln head cover 2 and the kiln head, the combustion air in the rotary kiln forms a uniform circulation, thereby increasing the wind speed and wind pressure entering the rotary kiln. This achieves the tangential spiral entry of the combustion air into the kiln. The Venturi effect formed by the embedded structure and the tapering slope 11 creates turbulence in the kiln, strengthening the mixing of the combustion air and the material, allowing the material to burn completely, improving the pollutant removal efficiency, and avoiding the problem of excessive emissions.

[0041] As an optional embodiment, the rapping controller includes a meshing drive gear 33 and a driven gear 34, and a drive unit that drives the drive gear. The rapper 32 is connected to the driven gear 34 via a connecting rod 35. Referring to Figure 3, the drive shaft of the drive gear 33 is rotated around its own central axis under the drive of the drive unit (motor, motor, etc.) to drive the meshing driven gear 34 to rotate accordingly.

[0042] As an optional embodiment of the drive unit driving the vibrator 32, when the hopper 30 does not need to be vibrated, the drive shaft of the drive gear 33 is stationary under the drive of the drive unit. The drive gear 33 limits the driven gear 34 through meshing, thereby limiting the vibrator 32 to a position away from the hopper 30. For example, the connecting rod 35 is horizontally set, and the vibrator 32 is located at the end of the connecting rod 35. When the hopper 30 needs to be vibrated, the drive shaft of the drive gear 33 rotates under the drive of the drive unit, causing the driven gear 34 to rotate until the vibrator 32 vibrates the bottom or side of the hopper 30. Alternatively, the drive unit disconnects the drive of the drive gear 33, and the drive shaft of the drive gear 33 can rotate freely. The driven gear 34 rotates under its own gravity until the vibrator 32 vibrates the bottom or side of the hopper 30.

[0043] As an optional embodiment, the vibratory controller further includes a counterweight 36 fixed to the connecting rod 35 and an elastic element 37 connecting the counterweight 36 and the vibrator 32. When the connecting rod 35 is rotated to a vertical position, the vibrator 32 vibrates the bottom or side of the hopper 30. This embodiment applies to situations where the drive unit stops driving the drive gear 33 when vibrating the hopper 30. When vibrating the hopper 30 is required, the drive unit stops driving the drive gear 33, the drive shaft of the drive gear 33 can rotate freely, the drive gear 33 loses its limiting effect on the driven gear 34, and the vibrator 32 rotates from a height to vibrate the bottom or side of the hopper 30 under its own weight and the weight 36. During the rapping process, the elastic element 37 deforms under stress, generating an elastic force. This elastic force acts on the rapper 32, causing it to vibrate or bounce, thus enabling multiple rapping actions of the rapper 32 on the hopper 30 to enhance the material feeding effect. In this embodiment, the elastic element 37 can be a spring, which generates a large deformation force after deformation, facilitating the vibration or bouncing of the rapper 32.

[0044] As an optional embodiment, the rapping controller further includes a position sensor for emitting a position signal when the hopper 30 is flipped to a predetermined position, and a controller for controlling the drive unit of the drive gear 33. The controller is communicatively connected to the position sensor and is used to control the drive unit to disconnect the drive of the drive gear 33 after receiving the position signal. This embodiment can automatically realize the linkage between the feeding of the hopper 30 and the rapping of the hopper 30 by the rapper 32. The position sensor can be an infrared sensor or a proximity sensor, both of which can emit a position signal after sensing that the hopper 30 has flipped to a predetermined position. Taking an infrared sensor as an example, the infrared sensor is set on one side of the tilting position of the hopper 30. When the hopper 30 is tilted to a preset position, such as the position shown in Figure 3, there is a possibility of residual material in the hopper 30. At this time, after the controller receives the electrical signal corresponding to the position signal, it controls the drive unit to stop driving the drive gear 33. The drive shaft of the drive gear 33 can rotate freely, and the drive gear 33 loses its limiting effect on the driven gear 34. Under the gravity of itself and the counterweight 36, the vibrator 32 drives the driven gear 34 to rotate downwards through the connecting rod 35 to vibrate the bottom or side of the hopper 30. During the vibration process, the elastic element 37 deforms under force and generates elastic force, which acts on the vibrator 32 and causes the vibrator 32 to vibrate. The vibrator 32 transmits the vibration to the hopper 30, which helps to increase the vibration and feeding effect of the hopper 30.

[0045] As an optional embodiment, the feeding device 4 includes a lifting section 40 and a pushing section 41. The lifting section 40 is used to carry materials and can be raised and lowered. The pushing section 41 is retractable and used to push the material into the feeding channel 10 when the lifting section 40 rises to the same level as the material. As shown in Figure 4, the lifting section 40 includes a platform for carrying materials and a hydraulic, pneumatic, or electric telescopic cylinder located below the platform to drive the platform to rise and fall. Similarly, the pushing section 41 has a retractable side for pushing materials, which pushes the material into the rotary kiln when extended. In use, the lifting section 40 vertically lifts the material to the same level as the pushing section 41 and the inlet of the rotary kiln, and then the pushing section 41 pushes it into the rotary kiln for incineration. This embodiment avoids the risks of hazardous waste packaging damage and leakage caused by dumping hazardous waste into the rotary kiln by a bucket elevator, leading to hazardous material spillage, volatilization, and fire.

[0046] As an optional embodiment, the feeding device 4 includes a shaft-type screw feeder 42 and a shaftless screw feeder 43 connected together. The inlet of the shaft-type screw feeder 42 is used to receive the material discharged from the hopper 30, and the outlet of the shaftless screw feeder 43 is connected to the feeding channel 10. Figure 5 shows an end view of the shaft-type screw feeder 42. As shown in Figures 5 and 6, in this embodiment, the feeding device 4 is a two-stage screw feeding device. The shaft-type screw feeder 42 is horizontally arranged, and a feed hopper 44 is arranged above it. The elevator continuously lifts the large-volume, low-density material into the feed hopper 44. The material in the feed hopper 44 enters the shaft-type screw feeder 42 under the action of gravity and is conveyed and sheared by the shaft, and then enters the shaftless screw feeder 43. The shaftless screw feeder 43 is connected to the kiln head hood 2, which compacts and evenly feeds the crushed material into the kiln body 1. The compacted material forms a material seal to prevent backfire. The feeding device 4 provided in this application embodiment can achieve continuous crushing and synchronous feeding, without being restricted by time. At the same time, through the two-stage spiral feeding structure, the material can be crushed, compacted and evenly fed into the rotary kiln. Combined with the tangential air distribution setting of the rotary kiln mentioned above, the material can be fully burned in the kiln, improving the combustion efficiency of the rotary kiln, effectively controlling the concentration of pollutants, and ensuring that emissions meet standards.

[0047] As an optional embodiment, the axial spiral feed unit 42 includes a screw 45 and a crusher 48. The screw 45 extends axially and is provided with spiral blades 46. A movable blade 47 is provided on the outer edge of the spiral blades 46. The crusher 48 is fixed to the outside of the movable blade 47 and is spaced apart from the movable blade 47. Referring to Figure 6, the crusher 48 is fixedly provided on the side wall of the equipment. The crusher 48 and the movable blade 47 work together to shear and crush the incoming material and reduce its volume, effectively preventing material entanglement and reducing the equipment failure rate.

[0048] As needed, the above technical solutions can be combined to achieve the best technical effect.

[0049] The above are merely the principles and preferred embodiments of the present invention. It should be noted that, for those skilled in the art, several other modifications can be made based on the principles of the present invention, and these modifications should also be considered within the scope of protection of the present invention.

Claims

1. A rotary kiln feeding assembly, characterized in that, include: Material dumping equipment, feeding equipment, and rotary kilns for hazardous waste incineration; The hazardous waste incineration rotary kiln includes: a kiln body, wherein the kiln body has a feeding channel at the kiln head; The kiln head hood is embedded in the feeding channel. A tapering slope is provided at the end of the feeding channel of the kiln head hood. A first air inlet and a second air inlet are respectively provided on opposite sides of the kiln head hood. The material dumping device includes a hopper for tipping and unloading material and a vibrating mechanism. The vibrating mechanism includes a vibrator and a vibrating controller. The vibrating controller controls the vibrator to vibrate the hopper when it is unloading material. The inlet of the feeding device receives the material from the hopper, and the outlet of the feeding device is connected to the kiln head hood. The vibrating controller includes a meshing drive gear and a driven gear, and a drive unit that drives the drive gear. The vibrator is connected to the driven gear via a connecting rod. The vibrating controller also includes a counterweight fixed to the connecting rod and an elastic element connecting the counterweight and the vibrator. When the connecting rod is rotated to a vertical position, the vibrator vibrates the bottom or side of the hopper.

2. The rotary kiln feeding assembly according to claim 1, characterized in that, The length of the kiln head hood embedded in the feed channel is L, 40mm≤L≤100mm.

3. The rotary kiln feeding assembly according to claim 2, characterized in that, The angle of inclination of the constricted slope is θ, where 2°≤θ≤5°.

4. The rotary kiln feeding assembly according to claim 1, characterized in that, The rapping controller also includes a position sensor for emitting a position signal when the hopper is flipped to a predetermined position and a controller for controlling the drive unit. The controller is communicatively connected to the position sensor and is used to control the drive unit to disconnect the drive of the drive gear after receiving the position signal.

5. The rotary kiln feeding assembly according to claim 1, characterized in that, The feeding device includes a lifting section and a pushing section. The lifting section is used to carry materials and can be raised and lowered. The pushing section is telescopically configured to push the materials into the feeding channel when the lifting section rises to the level of the materials.

6. The rotary kiln feeding assembly according to claim 1, characterized in that, The feeding device includes a shaft-type screw feeder and a shaftless screw feeder connected to each other. The inlet of the shaft-type screw feeder is used to receive the material from the hopper, and the outlet of the shaftless screw feeder is connected to the feeding channel.

7. The rotary kiln feeding assembly according to claim 6, characterized in that, The axial spiral feed section includes a screw and a crushing blade. The screw extends axially and is provided with spiral blades. A moving blade is provided on the outer edge of the spiral blade. The crushing blade is fixed to the outside of the moving blade and is spaced apart from the moving blade.

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