Hazardous waste incinerator

Abstract

The present invention discloses a hazardous waste incinerator, which includes: a frame; a rotary kiln, which is horizontally mounted on the frame, and the rotary kiln is cylindrical as a whole, and has the freedom to rotate around its own axis; the middle part of the rotary kiln is a heating zone, so that the rotary kiln is divided into a low-temperature zone, a heating zone and a high-temperature zone from the inlet to the outlet, wherein the low-temperature zone is the incineration zone, and the heating zone is a forced heating zone, and accordingly, the rotary kiln is provided with an auxiliary heating device in the heating zone; a partition, which is an axial partition mounted in the rotary kiln, and holes are distributed on the partition; a driving device, which is mounted on the frame and outputs to drive the rotary kiln. Based on the present invention, the hazardous waste can be effectively guaranteed to be fully burned, and the combustion efficiency is relatively high.

Description

Technical Field

[0001] The invention relates to a hazardous waste incinerator. Background Art

[0002] Hazardous waste is often referred to as hazardous waste, hazardous residue or hazardous waste, or simply hazardous waste. This term has been recognized by society as early as the early 1970s. After several years of development, it was not until the mid-1970s that it was gradually generally accepted. Due to its potential, long-term and non-recoverable hazards, in order to be able to more reasonably and safely treat hazardous waste, the definition of hazardous waste must be more precise.

[0003] Hazardous wastes are defined by the United Nations Environment Programme as those wastes that are harmful to the human environment, except for radioactivity, whether they are produced, disposed of or transported, either individually or in combination. Hazardous wastes are defined by the World Health Organization (WHO) as wastes that have physical, chemical or biological characteristics and require specific management and disposal processes in order to minimize their impact on the environment and human health.

[0004] At present, most domestic methods for treating hazardous waste are incineration or landfill. Landfill cannot quickly eliminate harmful components in hazardous waste because the natural degradation cycle of harmful components is long, and some cannot even be eliminated by natural degradation, such as pathogens contained in medical waste. In addition, landfill itself may pollute the soil or groundwater. Therefore, landfill is suitable for ordinary garbage, but not the correct way to treat hazardous waste. The main way to treat hazardous waste is still incineration.

[0005] The incineration of hazardous waste is mainly completed in an incinerator so that the hazardous waste can be burned in a controllable manner in a relatively closed environment. From the background technology center of the Chinese patent document CN211316191U, it can be seen that the composition and calorific value of garbage fluctuate greatly, and there is often a phenomenon of low temperature (it should be the furnace temperature is low), resulting in the appearance of dioxin pollutants. For this reason, in this patent document, it proposes a scheme of preheating the garbage and then incinerating it. It should be noted that due to the complex composition of garbage, the ignition point, calorific value, etc. are different, and it is usually necessary to crush the garbage and then mix a certain proportion of fuel to assist combustion. Fuels such as diesel are volatile fuels, which are very likely to produce a large amount of volatilization during preheating, and are very likely to cause explosions and accidents.

[0006] Chinese patent document CN204084402U discloses a monitoring device for the furnace temperature of a rotary kiln for treating domestic waste. Its background technology section also mentions that if the waste is not burned fully, dioxins that pollute the environment are easily produced. It has been scientifically proven that as long as the furnace temperature during waste incineration is guaranteed to be between 850°C and 1000°C, the residence time at high temperature is not less than 2 seconds, and there is sufficient air agitation, dioxins are controllable during the waste incineration process. For this reason, in this patent document, a closed-loop control method is used to control the temperature in the rotary kiln furnace. It does not specify what heating method is used for the temperature in the rotary kiln furnace, and how to make the waste fully burn. It focuses on proposing a closed-loop control method. Summary of the invention

[0007] The object of the present invention is to provide a hazardous waste incinerator which can effectively ensure the complete combustion of hazardous waste and has a relatively high combustion efficiency.

[0008] In an embodiment of the present invention, a hazardous waste incinerator is provided, comprising:

[0009] frame;

[0010] The rotary kiln is horizontally mounted on a frame, and the rotary kiln is cylindrical in shape as a whole, and has the freedom to rotate around its own axis; the middle part of the rotary kiln is a heating zone, so that the rotary kiln is divided into a low-temperature zone, a heating zone and a high-temperature zone from the inlet to the outlet, wherein the low-temperature zone is an incineration zone, and the heating zone is a forced heating zone. Accordingly, the rotary kiln is provided with an auxiliary heating device in the heating zone;

[0011] The partition is an axial partition installed in the rotary furnace, and holes are distributed on the partition;

[0012] The driving device is mounted on the frame, and outputs and drives the rotary kiln.

[0013] Optionally, there is one partition plate, which is arranged in the middle of the temperature rising zone.

[0014] Optionally, the rotary kiln is a three-segment structure;

[0015] Accordingly, the low temperature zone, the high temperature zone and the temperature rising zone are each constructed by a furnace section;

[0016] The furnace sections are connected by a detachable end face connection structure.

[0017] Optionally, the end face connection structure is a flange connection.

[0018] Optionally, the driving device comprises:

[0019] A large grinding roller, which is mounted on the rotary kiln and constitutes a driven grinding roller. There are two large grinding rollers, which are distributed in the axial direction of the rotary kiln.

[0020] Two small grinding rollers are provided corresponding to each large grinding roller, and the two small grinding rollers are supported symmetrically on the lower side of the large grinding roller to form active grinding rollers;

[0021] The motor provides the motive force;

[0022] Transmission mechanism to connect the small grinding roller and the motor.

[0023] Optionally, the transmission mechanism includes a flexible transmission mechanism.

[0024] Optionally, the flexible transmission mechanism is a belt transmission mechanism or a chain transmission mechanism.

[0025] Optionally, a group of lifting plates are provided in the rotary furnace section corresponding to the low temperature zone and in the rotary furnace section corresponding to the high temperature zone.

[0026] Optionally, the lifting plates in a group of lifting plates form a cantilever of a multi-head vortex, and the cantilever is a straight arm;

[0027] The angle between the lifting plate and the axis of the rotary kiln shall not exceed 15 degrees and not be less than 3 degrees.

[0028] Optionally, screening holes are distributed on the lifting plate.

[0029] It should be noted that the garbage incinerated by the waste incineration process is usually a mixture that has been crushed and mixed with a predetermined amount of fuel, but it is still usually called garbage; at the same time, in order to ensure the full combustion of the mixture, the waste incineration system is usually equipped with an air supply device. Therefore, there will be a certain amount of wind-based feeding pressure during the waste incineration process. It should also be noted that the hazardous waste incinerator is a component of the waste incineration system, not the entire system.

[0030] Furthermore, in the embodiment of the present invention, the wind selection capability of the feeding pressure based on the wind force is specifically that the particle size of the crushed garbage has a certain distribution, and in the process of garbage incineration, garbage with relatively large particles will usually be split into smaller particles, for example, branches will become fine ash after burning. The smaller the particles, the larger the specific surface area, and the stronger the ability to be transported by wind. In other words, the smaller the particles, the shorter the time the garbage exists in the incinerator, and the smaller the particles, the faster the burning speed. Therefore, the wind transportation itself has a screening effect, that is, wind selection. At the same time, in the embodiment of the present invention, a partition with holes is provided in the rotary furnace, which has a mechanical screening effect, so that the garbage with relatively large particle size can exist in the incinerator for a longer time, and the garbage with relatively small particle size can be pushed to the next stage through the holes based on the wind force, thereby ensuring that garbage of different particle sizes can be fully burned. The combustion of garbage itself will generate heat energy, but the temperature rise is relatively limited. For this reason, the configured incinerator is divided into three temperature zones in its axial area. The front stage is the incineration zone, that is, the natural combustion zone of garbage, followed by the heating zone, to raise the furnace temperature to a predetermined temperature to ensure the thermal decomposition of harmful components such as dioxins, and finally the high temperature zone, that is, the temperature in the furnace is maintained after heating to ensure that some harmful components produced by combustion are eliminated and meet the standardized emission requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the top view of the structure of a hazardous waste incinerator in one embodiment.

[0032] Figure 2 It is a schematic diagram of the main structure of a hazardous waste incinerator in one embodiment.

[0033] Figure 3 It is a schematic diagram of the top-down structure of a hazardous waste incinerator in one embodiment.

[0034] Figure 4 It is a schematic diagram of the left side structure of a hazardous waste incinerator in one embodiment.

[0035] Figure 5 It is a schematic diagram of the three-dimensional structure of a hazardous waste incinerator in one embodiment.

[0036] In the figure: 1. feed port, 2. low temperature zone, 3. main support, 4. heating zone, 5. motor, 6. motor support, 7. belt drive mechanism, 8. large grinding roller, 9. high temperature zone, 10. discharge port, 11. bearing seat, 12. small grinding roller, 13. bolt, 14. pre-tightening belt, 15. coupling, 16. transmission shaft, 17. inclined scraper, 18. ring groove, 19. nut, 20. partition plate, 21. inclined scraper. DETAILED DESCRIPTION

[0037] It should be noted that, as mentioned above, garbage usually needs to be crushed before incineration. Although the particles produced by crushing are relatively coarse, it can make the garbage have a certain particle distribution, so that it has relatively good combustion performance and better mixing uniformity with the fuel.

[0038] Before mixing with fuel, the waste is usually dry material with a relatively small moisture content.

[0039] It should be known that in the waste incineration process, wind power equipment is a necessary process equipment, and in facilities such as rotary kilns, the conveying direction generated by the wind is from the rotary kiln feed port 1 to the discharge port 10 .

[0040] It should be noted that in the embodiments of the present invention, low temperature and high temperature are a pair of relative concepts, wherein low temperature refers to the environment generated during waste incineration, and high temperature refers to the environment generated after heating.

[0041] Affected by the composition of garbage and the completeness of combustion, the temperature in the low-temperature zone 2 is not stable. The purpose of the temperature-raising zone 4 is to further heat the waste gas generated by the incineration of garbage, that is, the material to, for example, the dioxin pyrolysis zone. The temperature increase here is not to be increased to a given and determined temperature value, but to consider the pyrolysis temperature value of harmful components and the allowable maximum temperature of the furnace. Therefore, in an embodiment of the present invention, the temperature in the temperature-raising zone 4 is allowed to fluctuate, and the temperature in the high-temperature zone 9 is also allowed to fluctuate.

[0042] It can be seen from the background technology that the main harmful components can be basically eliminated when the temperature in the furnace reaches 850°C. As for the service life of the furnace, the lower the temperature, the longer its service life is. Therefore, based on the description in the background technology, it can be seen that the temperature in the furnace can be controlled below 1000°C and above 850°C. The entire range is 150°C, which can fully adapt to the instability of the temperature in the furnace caused by the instability of the garbage composition.

[0043] exist Figure 1~Figure 5 In the hazardous waste incinerator shown, its basic structure includes a main support 3, a rotary kiln with a low-temperature zone 2, a heating zone 4 and a high-temperature zone 9, a driving device for driving the rotary kiln to rotate, and a partition plate 20 installed in the rotary kiln, wherein the rotary kiln is used for the incineration of materials (recorded as a mixture of crushed garbage and fuel) and the digestion of harmful components such as dioxins generated by the incineration, the partition plate 20 mainly produces a mechanical screening effect, and the driving device mainly drives the rotary kiln to rotate around its own axis.

[0044] Figure 1 and Figure 5In the figure, the main support 3 and the motor support 6 are assembled into a steel truss, which is a statically determinate structure as a whole, called a frame. Compared with the mechanism, for a statically determinate structure, stability is a relatively higher requirement. The steel truss shown in the figure adopts a welded structure as a whole, mainly using, for example, channel steel components and angle steels for welding, wherein the beams of the steel truss structure are made of channel steel components, and the columns such as the legs are made of angle steel components, and channel steel components or I-beams and H-shaped steel components can also be used.

[0045] The rotary kiln adopts a horizontal structure and needs to be supported on the frame by a rolling bearing component so that it has the freedom to rotate around its own axis. Figure 1 The right end is the discharge end, which is adapted to have a discharge port 10 , and the left end is the feed end, which is adapted to have a feed port 1 .

[0046] As mentioned above, the rotary kiln is divided into three zones in the direction of material movement. The incineration zone is at the front stage. Because the garbage composition in the incineration zone is unstable, the temperature rise generated by combustion is unstable, but it is usually lower than 850°C, or it does not reach the desired temperature. Therefore, the incineration zone is called low-temperature zone 2. Because the temperature of the incineration zone does not reach the desired temperature, it is easy to produce harmful substances such as dioxins. Therefore, it is necessary to heat up the materials and flue gases flowing from the incineration zone. Heating requires a process, so an incinerator section is adapted. The furnace section is adapted with a heating device for heating the flowing materials and flue gases. Therefore, the furnace section is called the heating zone 4, in order to heat the flowing materials and flue gases to the desired temperature, such as above 850°C.

[0047] It should be known that the auxiliary heating device adapted for the temperature rising zone 4 must be adapted to the heat bearing capacity of the furnace section of the temperature rising zone 4 .

[0048] Furthermore, after the material and flue gas are heated to the desired temperature, they need to be maintained for a certain period of time, for example, more than 2 seconds. For this reason, based on the flow speed, a certain furnace section length is still required to adapt, so that the temperature zone of this furnace section is the high temperature zone 9.

[0049] Since garbage incineration requires separate configuration such as a blast system, rather than natural combustion, the existence of the blast system will cause the flue gas to pass through the incinerator faster, or the residence time of the flue gas in the incinerator will be shortened. For this reason, partitions are set in the rotary kiln, such as Figure 3 The partition plate 20 shown in the figure has through holes, which can increase the flow resistance, slow down the speed of the flue gas, and make the flue gas stay in the incinerator for a relatively long time, so that the combustible components therein can be fully burned and the components that are easy to pyrolyze can be fully pyrolyzed.

[0050] Similarly, the partition plate 20 with holes is equivalent to a sieve plate. The sieved part of the material is relatively fine material, which is easy to burn out and has a relatively large specific surface area. It is also easy to be carried by the airflow and has a relatively fast flow speed. The remaining part is relatively coarse material, which is split into smaller particles after being fully burned, so as not to affect the continuous incineration of the material.

[0051] Compared with other types of incinerators, the rotary kiln has the ability to rotate. Based on this ability, the material can be turned over without causing the problem of insufficient combustion in the deep layer. Therefore, in addition to the rotary freedom, the rotary kiln needs a drive device to drive it when it is in working state.

[0052] Correspondingly, the driving device is installed on the frame and outputs to drive the rotary kiln.

[0053] Regarding the number of partitions, there can be multiple or only one, and in a preferred embodiment, one is preferred because in the incineration zone, that is, the low-temperature zone 2, the material has not been fully burned and may contain relatively large particles. If a partition is set in the low-temperature zone 2, it may cause congestion of the material.

[0054] In the high temperature zone 9 , the materials are basically burned out, and the value of screening based on the partition is not great. Therefore, only one partition is required, and the partition is set in the middle of the temperature rising zone 4 .

[0055] Therefore, different furnace sections have different temperatures and different functions, which are not suitable for the overall structure. For this reason, the rotary furnace is divided into three furnace sections according to different functions. Accordingly, each functional area is adapted to a furnace section, that is, the low-temperature zone 2 corresponds to a furnace section, the heating zone 4 corresponds to a furnace section, and the high-temperature zone 9 corresponds to a furnace section.

[0056] Because it is a pipe body, the furnace sections are connected by a detachable end surface connection structure to form a coaxial sequential connection structure.

[0057] Preferably, the end face connection structure is a flange connection, which has a relatively mature structure and is easy to assemble.

[0058] Figure 3 In the embodiment, the flange adapted for the flange connection has an annular portion at the outer edge, thereby forming an annular groove 18 between the flange body and the furnace wall, in which the bolts 13 and nuts 19 can be accommodated. At the same time, the annular portion can be used to construct the large grinding roller 8.

[0059] Relatively speaking, the heating zone 4 is longer than the other two furnace sections. The axial position of the large grinding roller 8 determined based on the aforementioned structure enables the structure supporting the rotary kiln to have a relatively large span and better supporting stability.

[0060] Regarding the drive of the rotary kiln, first of all Figure 1 and 2 In the structure shown, the driving device includes:

[0061] The large grinding roller 8 is mounted on the rotary kiln to form a driven grinding roller. There are two large grinding rollers 8 distributed in the axial direction of the rotary kiln, which is adapted to the concept of constructing the large grinding roller 8 on the flange.

[0062] Two small grinding rollers 12 are provided corresponding to each large grinding roller 8, and the two small grinding rollers 12 are supported symmetrically on the lower side of the large grinding roller 8 to form active grinding rollers.

[0063] A motor 5 is provided to provide motive power, and then the small grinding roller 12 is connected to the motor through a transmission mechanism.

[0064] It should be known that the large grinding roller 8 and the small grinding roller 8 are transmitted based on friction, and size is a pair of relative concepts to obtain the desired transmission ratio.

[0065] Furthermore, the transmission mechanism includes a flexible transmission mechanism.

[0066] Optionally, the flexible transmission mechanism is a belt transmission mechanism 7 or a chain transmission mechanism.

[0067] As mentioned above, the purpose of the rotary function of the rotary kiln is to turn the material based on the rotation, so as to avoid the material layer being too thick and causing incomplete combustion of the bottom material. Furthermore, in order to improve the turning capacity, a group of lifting plates are provided in the rotary kiln section corresponding to the low temperature zone 2 and the rotary kiln section corresponding to the high temperature zone 9, such as Figure 3 The inclined scraper 17 shown in the figure enables the rotary kiln to have a certain carrying capacity and is easy to turn the materials higher and then fall.

[0068] In some preferred embodiments, the lifting plates in a group of lifting plates constitute a cantilever of a multi-head vortex, and the cantilever is a straight arm, so that the lifting plates have a certain conveying capacity, so that when materials with relatively large density cannot be conveyed by wind, they can move forward based on spiral conveying.

[0069] While having the desired conveying capacity, the conveying speed should not be too high. For this purpose, the angle is not greater than 15 degrees and not less than 3 degrees.

[0070] As mentioned earlier, screw conveying is mainly used to transport materials with relatively large particles and relatively high density forward, while screw conveying is not required for fine materials. For this reason, screening holes are distributed on the lifting plate to facilitate classified transportation.

Claims

1. A hazardous waste incinerator, characterized in that: include: frame; The rotary kiln is horizontally mounted on a frame, and the rotary kiln is cylindrical in shape as a whole, and has the freedom to rotate around its own axis; the middle part of the rotary kiln is a heating zone, so that the rotary kiln is divided into a low-temperature zone, a heating zone and a high-temperature zone from the inlet to the outlet, wherein the low-temperature zone is an incineration zone, and the heating zone is a forced heating zone. Accordingly, the rotary kiln is provided with an auxiliary heating device in the heating zone; The partition is an axial partition installed in the rotary furnace, and holes are distributed on the partition; A driving device, mounted on the frame and outputting a drive to drive the rotary kiln; The partition has one piece and is arranged in the middle of the temperature rising zone; A set of lifting plates is provided in the rotary furnace section corresponding to the low temperature zone and in the rotary furnace section corresponding to the high temperature zone; The lifting plates in a group of lifting plates form a cantilever of a multi-head vortex, and the cantilever is a straight arm; The angle between the lifting plate and the axis of the rotary kiln shall not exceed 15 degrees and not be less than 3 degrees; Screening holes are distributed on the lifting plate.

2. The hazardous waste incinerator according to claim 1, characterized in that: The rotary kiln has a three-segment structure; Accordingly, the low temperature zone, the high temperature zone and the temperature rising zone are each constructed by a furnace section; The furnace sections are connected by a detachable end face connection structure.

3. The hazardous waste incinerator according to claim 2, characterized in that: The end surface connection structure is a flange connection.

4. The hazardous waste incinerator according to claim 1, characterized in that: The driving device comprises: A large grinding roller, which is mounted on the rotary kiln and constitutes a driven grinding roller. There are two large grinding rollers, which are distributed in the axial direction of the rotary kiln. Two small grinding rollers are provided corresponding to each large grinding roller, and the two small grinding rollers are supported symmetrically on the lower side of the large grinding roller to form active grinding rollers; The motor provides the motive force; Transmission mechanism to connect the small grinding roller and the motor.

5. The hazardous waste incinerator according to claim 4, characterized in that: The transmission mechanism comprises a flexible transmission mechanism.

6. The hazardous waste incinerator according to claim 5, characterized in that: The flexible transmission mechanism is a belt transmission mechanism or a chain transmission mechanism.

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