A multi-stage pulse rotary pyrolysis reactor and its usage method

Abstract

The present invention provides a multi-stage pulse rotary pyrolysis reactor and a method for using the same, specifically belonging to the field of resource pyrolysis treatment of organic solid materials. The pyrolysis reactor of the present invention includes a rotary kiln rotating body, a kiln head combustion system, a feeding system, a rotary kiln positioning and transmission system, a reburning system, a kiln tail shunt system, and an ignition burner. The coupling of solid-solid heat exchange and gas-solid heat exchange effectively improves the heat exchange efficiency; the heat of the material to be pyrolyzed is utilized to the greatest extent, saving production costs; the multi-stage reburning system can ensure the complete progress of the pyrolysis reaction; the pulse porous medium combustion can effectively reduce the amount of flue gas generated and improve the quality of pyrolysis products; the special feeding and discharging structures ensure that gas does not flow back, and the operation is safer.

Description

Technical Field

[0001] The present invention relates to a multi-stage pulse rotary pyrolysis reactor, and specifically belongs to the field of resource pyrolysis treatment of organic solid materials. Background Art

[0002] As one of the important economies in the world, China generates a large amount of solid waste mainly composed of domestic waste, industrial solid waste and agricultural waste every year. The most widely used solid waste treatment methods currently include landfill, incineration, biological treatment, chemical recycling, etc. Among them, the landfill method will cause pollution to land, water sources and air, and while occupying a large amount of land resources, it cannot generate additional economic value, which does not meet the requirements of environmental protection and economic development; the incineration method has good treatment effects, but also has the defects of generating pollution and low economic value; the biological method has little pollution and can produce high-value products such as methane or fertilizers, but the disadvantage is that the treatment cycle is relatively long.

[0003] Pyrolysis treatment in chemical recycling can realize the recovery of solid waste resources while having a shorter treatment cycle, and it is a relatively economically valuable method among current solid waste treatment methods.

[0004] Rotary kiln pyrolysis reactors have the advantages of high reliability and large processing capacity, and are widely used in the field of solid waste pyrolysis. They can be divided into two types: indirect heating type and direct heating type according to different heating methods.

[0005] The indirect heating type rotary kiln heats the outer wall of the cylinder, and the heat is conducted from the outer wall of the cylinder to the solid waste, which will cause relatively high energy loss.

[0006] The direct heating type rotary kiln usually uses high-temperature flue gas or high-temperature hot solid carriers to achieve heat transfer. Generally speaking, using high-temperature flue gas as the pyrolysis medium will cause more heat loss in flue gas exhaust, and it is difficult to ensure a very high heat transfer efficiency in gas-solid heat transfer; while using high-temperature hot solid carriers for heating will lead to a multiple increase in the conveying capacity of the kiln, an increase in the floor area of the equipment and an increase in operating costs.

[0007] Currently widely used rotary kiln pyrolysis reactors all have some defects, and there has not yet appeared a rotary kiln pyrolysis reactor that takes into account both heat transfer efficiency and operating costs. Summary of the Invention

[0008] To solve the above problems, the present invention proposes a rotary pyrolysis reactor with higher heat transfer efficiency and stronger resource recovery ability, which can better realize the pyrolysis reaction while solving the problems of uneven heat transfer, coking and slagging caused by using high-temperature flue gas as the pyrolysis medium in the traditional method.

[0009] Technical Solution of the Present Invention

[0010] A multi-stage pulse rotary pyrolysis reactor, comprising a rotary kiln rotating body 1, a kiln head combustion system 2, a feeding system 3, a rotary kiln positioning and transmission system 4, a reburning system 5, a kiln tail shunt system 6 and an ignition burner. The feeding system 3 is connected to the kiln head end of the rotary kiln rotating body 1, the kiln head combustion system 2 is arranged at the kiln head part of the rotary kiln rotating body 1, the reburning system 5 is arranged at the middle and rear sections of the rotary kiln rotating body 1, and the number is more than one; the kiln tail shunt system 6 is connected to the kiln tail end of the rotary kiln rotating body 1.

[0011] The kiln head combustion system 2 includes a combustion heating chamber 15 and a porous ceramic cavity. The reburning system 5 includes a reburning gas mixing heating chamber 511 and a porous ceramic cavity. The combustion heating chamber 15 and the reburning gas mixing heating chamber 511 are both located inside the rotary kiln rotating body 1, and replace the position of a part of the rotating body heat preservation and wear-resistant material layer 13 on the inner surface of the original rotary kiln rotating body 1, are arranged on the cross-section in the axial direction of the rotary kiln rotating body 1, and are coaxial with the rotary kiln rotating body 1; a porous ceramic cylinder is coaxially arranged inside the combustion heating chamber 15 and the reburning gas mixing heating chamber 511; the porous ceramic cavity is the cavity possessed by the porous ceramic cylinder itself; the combustion areas of the kiln head combustion system 2 and the reburning system 5 are both inside the porous ceramic cavity.

[0012] Further, the parts of the rotary kiln rotating body 1 related to the kiln head combustion system 2 and the reburning system 5 have the structure from outside to inside in sequence as a rotating body cylinder steel plate 12, a rotating body heat preservation and wear-resistant material layer 13, a combustion heating chamber 15 or a reburning gas mixing heating chamber 511, a porous ceramic cylinder, and a rotary kiln pyrolysis zone 16; the other parts of the rotary kiln rotating body 1 have the structure from outside to inside in sequence as a rotating body cylinder steel plate 12, a rotating body heat preservation and wear-resistant material layer 13, and a rotary kiln pyrolysis zone.

[0013] Further, the material of the porous ceramic cylinder is SiC material, and its performance such as thermal conductivity, thermal shock resistance, and radiation emissivity is comprehensively superior to common ceramic materials such as zirconia and alumina. The porosity is limited to 50-90%, and bad combustion phenomena such as flashback, quenching, and flameout are eliminated.

[0014] Further, in the radial direction, the porous ceramic cylinder and the rotating body heat preservation and wear-resistant material layer 13 are fixed by a mechanical structure to ensure that when the pyrolysis reaction is carried out, the two remain relatively stationary and rotate coaxially. In the axial direction, a boss is arranged on the rotating body heat preservation and wear-resistant material layer 13 near the combustion heating chamber 15, and its height is the same as the thickness of the porous ceramic cylinder 14, and the porous ceramic cylinder 14 is positioned by this boss.

[0015] Further, the kiln head combustion system 2 includes a kiln head hood 21, a kiln head sealing device 22, an ignition burner 24, a kiln head combustion system pipeline 25, an annular graphite sealing layer 212, and fastening screws 213; each component for protecting the kiln head combustion system 2 is arranged in the kiln head hood 21, and the kiln head hood 21 and the rotary kiln rotating body 1 are rotationally and sealingly connected through the kiln head sealing device 22; the kiln head combustion system pipeline 25 is in an absolutely static state and includes a combustion gas main pipe 26, a combustion auxiliary gas main pipe 27, a combustion gas annular header 28, a combustion auxiliary gas annular header 29, gas branch pipes 210, and auxiliary gas branch pipes 211. One end of the combustion gas main pipe 26 and the combustion auxiliary gas main pipe 27 is connected to a gas source, and the other ends are respectively communicated with the combustion gas annular header 28 and the combustion auxiliary gas annular header 29. The combustion gas annular header 28 and the combustion auxiliary gas annular header 29 are concentrically arranged with the rotary kiln rotating body 1; one ends of the gas branch pipes 210 and the auxiliary gas branch pipes 211 are respectively vertically communicated with the annular surfaces of the combustion gas annular header 28 and the combustion auxiliary gas annular header 29, and the other ends extend through the annular graphite sealing layer 212 to the combustion heating cavity 15; the lengths of the gas branch pipes 210 and the auxiliary gas branch pipes 211 extending into the combustion heating cavity 15 are in different gradients, and two gas branch pipes 210 and two auxiliary gas branch pipes 211 with the same length form a group of branch pipes; the branch pipe groups with different length gradients are evenly and staggeredly arranged along the circumferential direction of the rotary kiln rotating body 1, and the different groups of branch pipes with the same length gradient are centrosymmetrically arranged along the circumferential direction of the rotary kiln rotating body 1 in space.

[0016] Further, the annular graphite sealing layer 212 is embedded between the rotating body heat preservation and wear-resistant material layer 13 and the high-temperature porous ceramic cylinder 14, and is fixed on the kiln head hood 21 through the fastening screws 213 and is in an absolutely static state.

[0017] Further, the feeding system 3 includes a feeding bin 31, a feeder, a feeder reducer 33, a feeder motor 34, and a feeding bin level gauge 35; the feeding bin level gauge 35 is arranged at different heights of the feeding bin 31 and is used to judge the material level height in the feeding bin 31. During the feeding process, it is necessary to ensure that there is a material level signal for the lowermost feeding bin level gauge 35; the feeder reducer 33 and the feeder motor 34 cooperate to control the material feeding speed.

[0018] Further, the reburning system 5 includes a reburning system cover, a reburning combustion gas path, a reburning zone, and a flexible seal for the reburning system. The reburning system cover is disposed around the rotary kiln rotating body 1, and the space formed with the rotary kiln rotating body 1 is a reburning mixing chamber 57; the reburning combustion gas path includes a reburning combustion-supporting gas path 51, a reburning fuel gas path 52, a reburning mixing chamber 57, and reburning mixing gas small holes 510; both the reburning combustion-supporting gas path 51 and the reburning fuel gas path 52 are communicated with the reburning mixing chamber 57 as gas inlets; the gas outlet is the reburning mixing gas small holes 510, and the reburning mixing gas small holes 510 are arranged circumferentially along the rotary kiln rotating body 1 and penetrate through the rotating body cylinder steel plate 12 and the rotating body heat-insulating and wear-resistant material layer 13. A metal fiber felt 59 is arranged circumferentially on the outer side of the rotary kiln rotating body 1 located in the reburning mixing chamber 57. The reburning zone includes a reburning mixed gas heating chamber 511 and a reburning high-temperature porous ceramic cylinder 512; the reburning high-temperature porous ceramic cylinder 512 is axially positioned by a boss provided by the rotating body heat-insulating and wear-resistant material layer 13, and a reburning mixed gas heating chamber 511 is arranged between the rotating body heat-insulating and wear-resistant material layer 13 and the reburning high-temperature porous ceramic cylinder 512. The flexible seal for the reburning system includes a flexible seal 53 for the reburning system and / or a graphite seal 58 for the reburning chamber. The said reburning system cover is in an absolutely static state.

[0019] Further, the tail-end shunt system 6 of the kiln includes a kiln tail cover 61 and a discharge bin 65 that are sequentially connected to the tail of the rotary kiln rotating body 1. A kiln tail seal 64 is connected between the tail of the rotary kiln rotating body 1 and the kiln tail cover 61; a pyrolysis gas outlet 62 is provided on the kiln tail cover 61, and the pyrolysis gas outlet 62 is connected to subsequent gas-solid separation and condensation separation modules to respectively generate pyrolysis fine ash, combustible non-condensable gas, and pyrolysis oil with economic value. The discharge bin 65 is used for storing pyrolysis residues, and a lock hopper 68 is connected to the lower part of the discharge bin 65, which can be used to discharge pyrolysis residues. The discharge bin level gauges 67 are configured at different heights of the discharge bin 65 for monitoring the level height in the discharge bin 65.

[0020] Further, a kiln head temperature measuring system 23, a rotating body temperature measuring device, a kiln tail temperature measuring device 63, and a discharge bin temperature measuring device are provided. The kiln head temperature measuring system 23 uses multiple wired thermocouples, and like the combustion-supporting gas branch pipes, it is inserted into the combustion heating chamber 15 from the annular graphite seal layer 212, and the insertion depth is the same; the rotating body temperature measuring device uses multiple rotating body wireless temperature measuring thermocouples 11 inserted into the pyrolysis zone of the rotary kiln; the kiln tail temperature measuring device 63 is arranged on the kiln tail cover 61 for detecting the pyrolysis gas temperature; the discharge bin temperature measuring device 66 is arranged on the discharge bin 65 for detecting the pyrolysis residue temperature.

[0021] A method for using a multi-stage pulse rotary pyrolysis reactor, characterized in that the process is as follows: The ignition burner heats the combustion heating chamber 15 and the reburning gas mixing chamber 511. After heating to a certain temperature, the gaseous fuel and the combustion-supporting gas are introduced into the kiln head combustion system 2 through pipelines and burned in the porous ceramic cavities of the porous ceramic cylinder. Then, the high-temperature flue gas enters the rotary kiln rotating body 1. At the same time, the material to be pyrolyzed is conveyed into the rotary kiln rotating body 1 through the feeding system 3. The material to be pyrolyzed is heated by the porous ceramic cylinder and the high-temperature flue gas to undergo a pyrolysis reaction. After the material continuously moves towards the kiln tail and leaves the pyrolysis zone with the porous ceramic cylinder, it enters the quasi-adiabatic space formed by the rotating body heat-insulating wear-resistant material layer 13. In this stage, the pyrolysis absorbs the waste heat of the flue gas and the heat stored in the heat-insulating layer, causing the temperature of the quasi-adiabatic space to continuously drop. Then, it passes through the reburning system 5, and the pyrolysis process of the reburning system 5 is the same as that in the kiln head combustion system 2. The residue after pyrolysis is discharged by the kiln tail diversion system 6, and the generated pyrolysis gas is led out for subsequent utilization.

[0022] Further, the gaseous fuel is non-condensable pyrolysis gas or other industrial combustible gases, and the combustion-supporting gas is pure oxygen.

[0023] The present invention has the following advantages compared with the traditional rotary pyrolysis reactor: 1. The coupling of solid-solid heat transfer and gas-solid heat transfer effectively improves the heat transfer efficiency; 2. Maximize the use of the heat of the material to be pyrolyzed itself, saving production costs; 3. The multi-stage reburning system can ensure the complete progress of the pyrolysis reaction; 4. Pulse-type porous medium combustion can effectively reduce the flue gas generation amount and improve the quality of pyrolysis products; 5. The special feeding and discharging structures ensure that the gas does not flow back, and the operation is safer. Description of the Drawings

[0024] Figure 1 It is the overall structure diagram of the multi-stage pulse rotary pyrolysis reactor equipment of the present invention.

[0025] Figure 2 It is the combustion gas pipeline diagram of the rotary kiln and the partial sectional view along the Figure 1 normal vertical plane.

[0026] Figure 3 It is the three-dimensional schematic diagram of the gas supply system.

[0027] Figure 4 It is the partial sectional view of the reburning system along the Figure 1 normal vertical plane.

[0028] 1. Rotary kiln rotating body; 11. Rotating body wireless temperature measuring thermocouple; 12. Rotating body cylinder steel plate; 13. Rotating body heat-insulating wear-resistant material layer; 14. High-temperature porous ceramic cylinder; 15. Combustion heating chamber; 16. Rotary kiln pyrolysis zone

[0029] 2. Kiln head combustion system; 21. Kiln head hood; 22. Kiln head sealing device; 23. Kiln head temperature measurement system; 24. Ignition burner; 25. Pipeline of kiln head combustion system; 26. Main gas pipe for combustion; 27. Main air pipe for combustion support; 28. Ring header for combustion gas; 29. Ring header for combustion support air; 210. Gas branch pipe; 211. Air branch pipe for combustion support; 212. Ring-shaped graphite sealing layer; 213. Fastening screw

[0030] 3. Feeding system; 31. Feeding bin; 32. Screw feeder; 33. Reducer of feeder; 34. Feeder motor; 35. Level gauge for feeding bin

[0031] 4. Rotary kiln positioning and drive system; 41. Tyre; 42. Supporting roller device; 43. Cooling water tank for supporting roller; 44. Thrust roller device; 45. Large gear ring; 46. Small gear ring; 47. Driving device

[0032] 5. Reburning system; 51. Air path for reburning support air; 52. Gas path for reburning gas; 53. Flexible seal of reburning system; 54. Support of reburning system; 55. Reburning outer shell; 56. Inner lining of reburning outer shell; 57. Reburning mixing chamber; 58. Graphite seal of reburning chamber; 59. Metal fiber felt; 510. Small holes for reburning mixing gas; 511. Heating chamber for reburning mixed gas; 512. High-temperature porous ceramic cylinder for reburning

[0033] 6. Kiln tail shunt system; 61. Kiln tail hood; 62. Pyrolysis gas outlet; 63. Temperature measurement device at kiln tail; 64. Kiln tail seal; 65. Discharge bin; 66. Temperature measurement device for discharge bin; 67. Level gauge for discharge bin; 68. Air lock; 69. Air lock motor Detailed implementation mode

[0034] It should be noted that the terms "insert", "up", "inside", "outside", etc. used in the present invention are only used to indicate directions, rather than indicating that the indicated devices or components must have a specific direction, be constructed and operated in a specific direction, so it should not be construed as a limitation to the present invention

[0035] The present invention will be described in detail below with reference to the drawings and in combination with the implementation mode. In this implementation mode, a rotary kiln pyrolysis reactor for pyrolyzing high calorific value solid waste residue is taken as an example, but it does not limit that the pyrolysis raw material of this pyrolysis reactor is only high calorific value solid waste residue

[0036] The present invention relates to a multi-stage pulse rotary pyrolysis reactor, which mainly includes: a rotary kiln rotating body 1, a kiln head combustion system 2, a feeding system 3, a rotary kiln positioning and drive system 4, a reburning system 5, and a kiln tail shunt system 6. The kiln head combustion system 2 is used to achieve functions such as preheating during pyrolysis, ignition and heating of the gas at the kiln head, and kiln head sealing. The rotary kiln rotating body 1 is located between the kiln head combustion system 2 and the kiln tail shunt system 6. High calorific value solid waste residues are fed from the feeding system 3, and pyrolysis occurs in the rotary kiln rotating body 1. The pyrolysis gas generated is discharged from the pyrolysis gas outlet 62 located in the kiln tail shunt system 6, and the residues after pyrolysis are discharged from the air lock 68 located at the lower end of the kiln tail shunt system 6.

[0037] Before the multi-stage pulse rotary pyrolysis reactor conducts material pyrolysis treatment, it is necessary to first operate the ignition burner 24 located on the kiln head combustion system 2. The ignition burner 24 continuously burns to raise the average temperature of the entire rotary kiln rotating body 1 to the lowest pyrolysis temperature. At this time, the feeding system 3 is operated to feed the high calorific value solid waste residues to be pyrolyzed, and the pyrolysis reaction starts. After sufficient pyrolysis gas is generated, the ignition burner 24 can be turned off. The pyrolysis gas contains a large amount of combustible gas components such as methane, hydrogen, and carbon monoxide. After dust removal, condensation, and purification, it forms non-condensable gas, which can be used as the heat source gas for subsequent pyrolysis reactions.

[0038] The high calorific value solid waste residues are fed into the rotary kiln rotating body 1 by the feeding system 3. The feeding system 3 is mainly composed of a feeding bin 31 and a screw feeder 32. The high calorific value solid waste residues rotate with the screw feeder 32 and are gradually fed into the rotary kiln rotating body 1. The material feeding speed is determined by the feeder reducer 33 and the feeder motor 34. At the same time, the multi-stage feeding bin level gauge 35 is used to judge the level height in the bin. During the feeding process, it is necessary to ensure that there is a level signal from the lowest layer feeding bin level gauge, that is, the feeding bin 31 ensures that there is always high calorific value solid waste residues, so as to achieve material plugging and prevent the pyrolysis gas from backflowing from the feeding bin 31, causing safety accidents and pollution. To achieve the above functions, it is necessary to perform the interlocking function of the feeder motor 34 and the feeding bin level gauge 35 before operation, so that the prerequisite for the motor to rotate is that there is a level signal from the lowest layer feeding bin level gauge.

[0039] The high-calorific value solid waste residue enters the pyrolysis zone 16 of the rotary kiln body 1 in the rotary kiln. At this time, the non-condensable gas is fed into the above-mentioned non-condensable gas through the main combustion gas pipe 26 located on the kiln head combustion system 2, and at the same time, pure oxygen is fed into the main combustion assistant gas pipe 27. The two respectively enter the combustion heating chamber 15 through the combustion gas annular header 28, the gas branch pipe 210 and the combustion assistant gas annular header 29, and the assistant gas branch pipe 211. Due to the combustion heating of the ignition burner 24, the high-temperature porous ceramic cylinder 14, which is the only outlet of the combustion heating chamber 15, has been heated to a sufficient temperature. At this time, the mixed gas of non-condensable gas and pure oxygen will carry out a porous medium combustion reaction in the high-temperature porous ceramic cylinder 14 and release a large amount of heat. The released heat energy further heats the high-temperature porous ceramic cylinder 14 and transfers the heat to the high-calorific value solid waste residue, promoting its pyrolysis reaction; in addition, the high-temperature flue gas generated by the porous medium combustion reaction will also penetrate into the rotary kiln pyrolysis zone 16, becoming the driving heat source for the pyrolysis reaction to occur.

[0040] Furthermore, the rotary kiln body 1 includes a rotary cylinder steel plate 12, a rotary heat-insulating and wear-resistant material layer 13, and a high-temperature porous ceramic cylinder 14. The combustion heating chamber 15 is surrounded by the rotary heat-insulating and wear-resistant material layer 13, the high-temperature porous ceramic cylinder 14, and the annular graphite sealing layer 212. The inlets are the gas branch pipe 210 and the assistant gas branch pipe 211, and the outlet is the porous structure of the high-temperature porous ceramic cylinder 14; the gas branch pipe 210 and the assistant gas branch pipe 211 are made of high-temperature resistant materials and are connected to their respective annular headers through sealing joints.

[0041] Even further, the rotary heat-insulating and wear-resistant material layer 13 and the high-temperature porous ceramic cylinder 14 are fixed by a mechanical structure to ensure that during the pyrolysis reaction, the two remain relatively stationary and rotate coaxially, while the annular graphite sealing layer 212 is fixed to the kiln head cover 21 by fastening screws 213 and is in an absolutely stationary state.

[0042] Even further, the annular graphite sealing layer 212 has the characteristics of high sealing performance, high temperature resistance, and wear resistance, ensuring that gas cannot reverse flow from the kiln head.

[0043] Even further, the kiln head sealing device 22 selects a flexible sealing structure to ensure good sealing performance even in the case of a certain movement deviation.

[0044] Even further, the lengths of the gas branch pipe 210 and the assistant gas branch pipe 211 in the same group are the same, and the outlet positions are evenly arranged along the axial direction of the rotary kiln body 1 until approaching the farthest end from the kiln head of the high-temperature porous ceramic cylinder 14; the above-mentioned pipes in the same group are symmetrically arranged along the center line of the rotary kiln body 1 to ensure that the flue gas uniformly penetrates into the rotary kiln pyrolysis zone 16 from the high-temperature porous ceramic cylinder 14.

[0045] Furthermore, solenoid valves are provided on the main gas combustion pipe 26 and the main auxiliary gas combustion pipe 27, which are pulsed to open and close. The operating conditions are interlocked with the kiln head temperature measurement system 23 and the rotating body wireless temperature measurement thermocouple 11. It passes through the annular graphite sealing layer for sealing and positioning from the kiln head direction, and inserts multiple thermocouples into the combustion heating chamber, near the outlet of the gas branch pipe. Once the temperature of the above-mentioned temperature measurement point is lower than the preset threshold, the electromagnetic valve opens and a porous medium combustion reaction occurs, providing more heat for pyrolysis; when the temperature of the above-mentioned temperature measurement point is higher than the preset threshold, the solenoid valve closes, and the heat source for the pyrolysis reaction is only the heat stored in the high-temperature porous ceramic cylinder 14. By repeatedly opening and closing the solenoid valve in this way, energy can be saved to the greatest extent, the smoke content in the pyrolysis gas can be reduced, and the highest-quality pyrolysis products can be obtained as much as possible.

[0046] The high-calorific value solid waste residue absorbs heat and undergoes pyrolysis in the columnar space formed by the high-temperature porous ceramic cylinder 14. After the material continuously moves towards the kiln tail and leaves the above-mentioned columnar space, it enters the quasi-adiabatic space formed by the rotating body heat-insulating and wear-resistant material layer 13. In this stage, the pyrolysis absorbs the waste heat of the flue gas and the heat stored in the heat-insulating layer, causing the temperature of the above-mentioned quasi-adiabatic space to continuously decrease.

[0047] Preferably, one or more reburning systems 5 are provided in the pyrolysis reactor of the present invention to heat the high-calorific value solid waste residue with a continuously decreasing temperature and provide the heat energy required for re-pyrolysis.

[0048] Preferably, the rotary kiln positioning and transmission system 4 includes a tyre 41, a supporting roller device 42, a supporting roller cooling water tank 43, a retaining ring device 44, a large gear ring 45, a small gear ring 46 and a driving device 47; among them, the tyre 41 is fixed to the rotary kiln through a backing plate and a seat plate, drives a pair of supporting rollers to rotate, and the overall support of the rotary kiln is realized by the supporting roller device 42. Multiple groups of the tyre 41 and the supporting roller device 42 are provided to evenly support the overall weight of the rotary kiln. One or several groups are configured with a retaining ring device 44 to limit the axial movement of the rotary kiln; the large gear ring 45 is respectively connected to the fixed brackets on the outer side of the rotating body cylinder steel plate 12 through bolts to achieve fixation, and the small gear ring 46 is driven to rotate by the driving device 47, thereby driving the large gear ring 45 and the entire rotary kiln to rotate.

[0049] More preferably, the above reburning system 5 is surrounded by a reburning outer shell 55, a rotary kiln rotating body 1, and a reburning high-temperature porous ceramic cylinder 512. The above non-condensable gas is introduced into the system as fuel gas through the reburning fuel gas pipeline 52, and pure oxygen is introduced into the system as auxiliary fuel gas through the reburning auxiliary fuel gas pipeline 51. After the non-condensable gas and pure oxygen are mixed in the reburning mixing chamber 57, they enter the reburning high-temperature porous ceramic cylinder 512 from the metal fiber felt 59 and the small holes 510 of the reburning mixed gas. The mixed gas is ignited by the high-temperature ceramic material and burns in the ceramic small holes, releasing heat to heat the reburning high-temperature porous ceramic cylinder 512. Similarly, the reburning high-temperature porous ceramic cylinder 512 and the high-temperature flue gas generated by combustion can provide heat for the secondary pyrolysis of high-calorie solid waste residues.

[0050] More preferably, the rotary kiln rotating body 1 rotates and the reburning outer shell 55 remains stationary. The seal between the two is composed of a composite seal structure consisting of a flexible seal 53 of the reburning system and a graphite seal 58 of the reburning chamber, ensuring that the mixed gas cannot leak during the pyrolysis process.

[0051] More preferably, the metal fiber felt 59 is evenly laid on the outside of the small holes 510 of the reburning mixed gas. The finer pores of the metal fiber felt 59 can effectively prevent the flame burning inside the reburning high-temperature porous ceramic cylinder 512 from flashing back to the reburning mixing chamber 57, preventing the risk of deflagration.

[0052] After the high-calorie solid waste residues are heated and decomposed by multiple reburning systems 5, they move to the tail of the rotary kiln rotating body 1 and then enter the kiln tail diversion system 6, successively fall into the discharge bin 65, and are discharged from the system through the outlet of the air lock 68. Then, mechanical conveying equipment such as a chain conveyor or a screw cooler can be used to transfer, utilize, or store them.

[0053] Furthermore, the function of the kiln tail diversion system 6 is to ensure the discharge of pyrolysis residues, the extraction of pyrolysis gas, and the sealing and non-diffusion of pyrolysis products. It is surrounded by a kiln tail cover 61 and a discharge bin 65, and both are internally provided with a heat preservation layer to protect the steel and prevent heat loss.

[0054] Even further, the kiln tail diversion system 6 prevents the pyrolysis gas from overflowing through the kiln tail seal 64. This seal structure selects a flexible seal to improve the mechanical fault tolerance rate.

[0055] The above-mentioned kiln head seal device, flexible seal of the reburning system, and kiln tail seal all adopt a composite flexible seal form. On the basis of using the traditional fish scale friction seal, a wear-resistant and high-temperature-resistant non-metallic material is fixedly laid on the outside of the rotary kiln rotating body 1, so that the fish scales and the non-metallic material rub against each other to ensure the system seal to the greatest extent.

[0056] Even further, a temperature measuring device 66 for the discharge bin is arranged on the side wall of the discharge bin to monitor the pyrolysis condition in the rotary kiln rotating body 1.

[0057] Furthermore, a multi-stage level gauge 67 for the discharge bin sidewall is arranged to monitor the material level height in the discharge bin 65. During the operation of the system, it is necessary to ensure that there is a continuous material level signal in the lowest two-stage level gauges of the discharge bin. With the special discharge structure of the air lock 68 and the determined interlock logic between the two, it can prevent outside air from flowing back from the outlet of the air lock 68 into the cavity of the kiln tail diversion system 6, preventing an explosion from occurring due to the mixing of air in a location with a relatively high temperature and a large amount of combustible pyrolysis gas.

[0058] All heated sections of the pyrolysis reactor are arranged with temperature measuring devices of different types and uses, which can real-time feedback the operating state of the system, and can adjust the pyrolysis state according to the real-time operating parameters, so as to improve the pyrolysis efficiency as much as possible on the premise of maintaining the stable operation of the system.

[0059] The present invention is also applicable to the pyrolysis of low calorific value materials. Only need to replace the said fuel gas with other industrial combustible gases such as methane, hydrogen, etc., and at the same time adjust the opening / closing frequency of the solenoid valve; for materials with very high calorific value, a steam generator can be configured to burn the excess non-condensable gas, and the generated steam can be used as plant steam or for other purposes such as drying, refrigeration, heating, etc.

Claims

1. A multi-stage pulse rotary pyrolysis reactor, characterized in that, It includes a rotary kiln rotating body (1), a kiln head combustion system (2), a feeding system (3), a rotary kiln positioning and driving system (4), a reburning system (5), a kiln tail shunt system (6) and an ignition burner; the feeding system (3) is connected to the kiln head end of the rotary kiln rotating body (1), the kiln head combustion system (2) is arranged at the kiln head part of the rotary kiln rotating body (1), the reburning system (5) is arranged at the middle and rear sections of the rotary kiln rotating body (1), and the number is more than one; the kiln tail shunt system (6) is connected to the kiln tail end of the rotary kiln rotating body (1). The kiln head combustion system (2) includes a combustion heating chamber (15) and a porous ceramic hole chamber, and the reburning system (5) includes a reburning gas mixing heating chamber (511) and a porous ceramic hole chamber; both the combustion heating chamber (15) and the reburning gas mixing heating chamber (511) are located inside the rotary kiln rotating body (1), and replace part of the rotating body heat preservation and wear-resistant material layer (13) on the inner surface of the original rotary kiln rotating body (1), are arranged on the cross-section in the axial direction of the rotary kiln rotating body (1), and are coaxial with the rotary kiln rotating body (1); the porous ceramic cylinder is coaxially arranged inside the combustion heating chamber (15) and the reburning gas mixing heating chamber (511); the porous ceramic hole chamber is the hole chamber possessed by the porous ceramic cylinder itself; the combustion areas of the kiln head combustion system (2) and the reburning system (5) are both inside the porous ceramic hole chamber. The material of the porous ceramic cylinder is SiC material, and its properties such as thermal conductivity, thermal shock resistance, and radiation emissivity are all superior to common ceramic materials such as zirconia and alumina. The porosity is limited to 50-90%, eliminating bad combustion phenomena such as flashback, quenching, and flameout; the porous ceramic cylinder and the rotating body heat preservation and wear-resistant material layer (13) are fixed through a mechanical structure to ensure that when the pyrolysis reaction occurs, the two remain relatively stationary and rotate coaxially; axially, a boss is arranged near the combustion heating chamber (15) on the rotating body heat preservation and wear-resistant material layer (13), and its height is the same as the thickness of the porous ceramic cylinder, and the porous ceramic cylinder is positioned through this boss.

2. The multi-stage pulsed rotary pyrolysis reactor according to claim 1, characterized in that, For the part of the rotary kiln rotating body (1) related to the kiln head combustion system (2) and the reburning system (5), the structure from the outside to the inside is successively a rotating body cylinder steel plate (12), a rotating body heat preservation and wear-resistant material layer (13), a combustion heating chamber (15) or a reburning gas mixing heating chamber (511), a porous ceramic cylinder, and a rotary kiln pyrolysis zone (16); for other parts of the rotary kiln rotating body (1), the structure from the outside to the inside is successively a rotating body cylinder steel plate (12), a rotating body heat preservation and wear-resistant material layer (13), and a rotary kiln pyrolysis zone.

3. A multi-stage pulsed rotary pyrolysis reactor according to claim 1, wherein, The kiln head combustion system (2) includes a kiln head hood (21), a kiln head sealing device (22), an ignition burner (24), a kiln head combustion system pipeline (25), an annular graphite sealing layer (212), and fastening screws (213); each component for protecting the kiln head combustion system (2) is arranged in the kiln head hood (21), and the kiln head hood (21) and the rotary kiln rotating body (1) are rotationally and sealingly connected through the kiln head sealing device (22); the kiln head combustion system pipeline (25) is in an absolutely static state and includes a combustion gas main pipe (26), a combustion auxiliary gas main pipe (27), a combustion gas annular header (28), a combustion auxiliary gas annular header (29), gas branch pipes (210), and auxiliary gas branch pipes (211); one end of the combustion gas main pipe (26) and the combustion auxiliary gas main pipe (27) is connected to a gas source, and the other ends are respectively communicated with the combustion gas annular header (28) and the combustion auxiliary gas annular header (29), and the combustion gas annular header (28) and the combustion auxiliary gas annular header (29) are concentrically arranged with the rotary kiln rotating body (1); one end of each of the gas branch pipes (210) and the auxiliary gas branch pipes (211) is vertically communicated with the annular surface of the combustion gas annular header (28) and the combustion auxiliary gas annular header (29) respectively, and the other end extends through the annular graphite sealing layer (212) into the combustion heating chamber (15); the lengths of the gas branch pipes (210) and the auxiliary gas branch pipes (211) extending into the combustion heating chamber (15) are at different gradients, and two gas branch pipes (210) and auxiliary gas branch pipes (211) with the same length form a group of branch pipes; the branch pipe groups with different length gradients are evenly and staggeredly arranged along the circumferential direction of the rotary kiln rotating body (1), and the different groups of branch pipes with the same length gradient are centrosymmetrically arranged along the circumferential direction of the rotary kiln rotating body (1) in space.

4. The multi-stage pulse rotary pyrolysis reactor according to claim 3, characterized in that, The annular graphite sealing layer (212) is embedded between the rotating body heat preservation and wear-resistant material layer (13) and the porous ceramic cylinder and is fixed on the kiln head hood (21) through the fastening screws (213) and is in an absolutely static state.

5. A multi-stage pulse rotary pyrolysis reactor according to claim 1, characterized in that, The feeding system (3) includes a feeding bin (31), a feeder, a feeder reducer (33), a feeder motor (34), and a feeding bin level gauge (35); the feeding bin level gauge (35) is arranged at different heights of the feeding bin (31) and is used to judge the material level height in the feeding bin (31), and a material level signal of the lowermost feeding bin level gauge (35) needs to be ensured during the feeding process; the feeder reducer (33) and the feeder motor (34) cooperate to control the material feeding speed.

6. A multi-stage pulse rotary pyrolysis reactor according to claim 1, characterized in that, The reburning system (5) includes a reburning system cover, a reburning combustion gas path, a reburning zone, and a reburning system seal; the reburning system cover is arranged around the rotary kiln rotating body (1), and the space formed with the rotary kiln rotating body (1) is a reburning mixing chamber (57); the reburning combustion gas path includes a reburning combustion-supporting gas path (51), a reburning fuel gas path (52), a reburning mixing chamber (57), and reburning mixing gas small holes (510); both the reburning combustion-supporting gas path (51) and the reburning fuel gas path (52) are communicated with the reburning mixing chamber (57) as gas inlets; the gas outlet is the reburning mixing gas small holes (510), and the reburning mixing gas small holes (510) are arranged circumferentially along the rotary kiln rotating body (1) and penetrate through the rotating body cylinder steel plate (12) and the rotating body heat preservation and wear-resistant material layer (13); a metal fiber felt (59) is arranged circumferentially outside the rotary kiln rotating body (1) located in the reburning mixing chamber (57); the reburning zone includes a reburning mixed gas heating chamber (511) and a reburning high-temperature porous ceramic cylinder (512); the reburning high-temperature porous ceramic cylinder (512) is axially positioned by a boss provided by the rotating body heat preservation and wear-resistant material layer (13), and a reburning mixed gas heating chamber (511) is arranged between the rotating body heat preservation and wear-resistant material layer (13) and the reburning high-temperature porous ceramic cylinder (512); the reburning system seal includes a reburning system flexible seal (53) and / or a reburning chamber graphite seal (58); the said reburning system cover is in an absolutely static state.

7. A multi-stage pulse rotary pyrolysis reactor according to claim 1, characterized in that, The said kiln tail diversion system (6) includes a kiln tail cover (61) and a discharge bin (65) which are sequentially connected to the tail of the rotary kiln rotating body (1); the tail of the rotary kiln rotating body (1) is connected to the kiln tail cover (61) through a kiln tail seal (64); a pyrolysis gas outlet (62) is arranged on the kiln tail cover (61), and the pyrolysis gas outlet (62) is connected to subsequent gas-solid separation and condensation separation modules to respectively produce pyrolysis fine ash, combustible non-condensable gas, and pyrolysis oil with economic value; the discharge bin (65) is used for storing pyrolysis residues, and the lower part of the discharge bin (65) is connected to a lock hopper (68) which can be used to discharge pyrolysis residues; the discharge bin (65) is equipped with a discharge bin level gauge (67) at different heights for monitoring the level height in the discharge bin (65).

8. The multi-stage pulse rotary pyrolysis reactor according to claim 1, wherein The said multi-stage pulse rotary pyrolysis reactor is also provided with a kiln head temperature measuring system (23), a rotating body temperature measuring device, a kiln tail temperature measuring device (63), and a discharge bin temperature measuring device; the kiln head temperature measuring system (23) uses multiple wired thermocouples and inserts into the combustion heating chamber (15) from the annular graphite sealing layer (212) in the same way as the combustion-supporting gas branch pipes and with the same insertion depth; the rotating body temperature measuring device uses multiple rotating body wireless temperature measuring thermocouples (11) to insert into the rotary kiln pyrolysis zone; the kiln tail temperature measuring device (63) is arranged on the kiln tail cover (61) for detecting the pyrolysis gas temperature; the discharge bin temperature measuring device (66) is arranged on the discharge bin (65) for detecting the pyrolysis residue temperature.

9. A method for using a multi-stage pulse rotary pyrolysis reactor according to any one of claims 1-8, characterized in that, The process is as follows: The ignition burner heats the combustion heating chamber (15) and the reburning gas mixing heating chamber (511). After heating to a certain temperature, the gaseous fuel and the combustion-supporting gas are introduced into the kiln head combustion system (2) through pipelines. After combustion in the porous ceramic holes of the porous ceramic cylinder, the high-temperature flue gas enters the rotary kiln rotating body (1). At the same time, the material to be pyrolyzed is conveyed into the rotary kiln rotating body (1) via the feeding system (3). The material to be pyrolyzed is heated by the porous ceramic cylinder and the high-temperature flue gas to undergo a pyrolysis reaction. After the material continuously moves towards the kiln tail and leaves the pyrolysis zone with the porous ceramic cylinder, it enters the quasi-adiabatic space formed by the rotating body heat-insulating wear-resistant material layer (13). In this stage, the pyrolysis absorbs the waste heat of the flue gas and the heat stored in the heat-insulating layer, causing the temperature of the quasi-adiabatic space to continuously drop. Then it passes through the reburning system (5), and the pyrolysis process of the reburning system (5) is the same as that in the kiln head combustion system (2). The residue after pyrolysis is discharged at the kiln tail shunt system (6), and the generated pyrolysis gas is led out for subsequent utilization.

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