A hazardous waste incineration slag drying device and an on-line drying system for hazardous waste incineration slag

Abstract

The present invention discloses a hazardous waste incineration slag drying device and an on-line drying system for hazardous waste incineration slag, comprising: a drying box, including a box body and a jacket located on the outer periphery of the box body, a heating chamber for the circulation of a heating medium is formed between the jacket and the box body, and the jacket is provided with an inlet and an outlet communicating with the heating chamber; a belt conveying mechanism, including a plurality of belt conveyors, the output end of each belt conveyor located upstream is respectively directly above the input end of the belt conveyor located downstream of it; the output end of the belt conveyor located at the most upstream extends through the drying box into the box body; a plurality of belt conveyors located in the middle reaches are all located in the box body; the output end of the belt conveyor located at the most downstream extends through the drying box to the outside of the box body; a gas collecting hood and a water collecting tank, which are respectively located at the top and bottom of the box body and communicate with the inside of the box body. The present invention adopts non-contact heat exchange combined with multi-belt conveyors for transfer, enabling the hazardous waste incineration slag to be fully contacted with the heat source and having a good drying effect.

Description

Technical Field

[0001] The present invention relates to the technical field of hazardous waste treatment, and particularly relates to a drying device for hazardous waste incineration slag and an on-line drying system for hazardous waste incineration slag. Background Art

[0002] Incineration is considered to be the most effective method for treating hazardous waste because it can achieve the reduction, harmlessness, and resource utilization of waste, and it plays an important role in waste management in developed countries. The residues and fly ash generated during the incineration of hazardous waste (generally collectively referred to as ash slag, accounting for about 20-25% of the treatment volume) have been classified as hazardous waste (HW18 incineration disposal residues) in the National Hazardous Waste List, and their disposal methods have always attracted much attention.

[0003] The slag after incineration of hazardous waste is generally discharged from the kiln tail. The slag discharge port at the kiln tail is sealed with water seal. The discharged ash slag is quickly cooled by the water seal water and then water quenched, and finally discharged by the slag discharge machine. At present, most hazardous waste incineration treatment enterprises collect and package the slag discharged from the slag discharge machine using ton bags. The ton bags filled with slag are placed in the hazardous waste temporary storage warehouse and left to stand for water filtration before being directly sent to the hazardous waste landfill for landfill treatment. The newly produced slag contains free water and needs to be placed at a designated location to control water and air dry. The water control time exceeds 1 month, and the amount of water that can be discharged is quite limited. The moisture content of the slag during transfer and landfill is relatively high, at 15-30%, which increases the disposal cost and reduces the economic benefits of hazardous waste incineration treatment enterprises.

[0004] Some hazardous waste incineration treatment enterprises have built a slag drying line to dry the newly produced slag with a relatively high moisture content, so as to reduce the landfill cost, but there are still the following problems:

[0005] 1. The non-on-line slag drying technology makes the slag move back and forth, greatly increasing the labor force and having a risk of secondary pollution;

[0006] 2. The existing on-line slag drying technology uses steam to dry the slag, the steam utilization value is low, the slag disposal cost is high, and the economic benefit is low;

[0007] 3. Some on-line slag drying technologies use the incineration flue gas at the input end of the high-temperature bag filter to dry the slag. The flue gas is in direct contact with the slag, and the heat of the flue gas takes away the moisture of the slag. The moisture content of the flue gas is too high, and when it returns to the front end of the bag filter for treatment, the situation of "bag sticking" occurs, seriously affecting the continuous and stable operation of the incineration system. Summary of the Invention

[0008] One of the objectives of the present invention is to provide a drying device for hazardous waste incineration slag, which uses non-contact heat exchange to dry the hazardous waste incineration slag and transfers it through multiple belt conveyors to increase the residence time of the hazardous waste incineration slag, enabling the hazardous waste incineration slag to be in full contact with the heat source and having a good drying effect.

[0009] To achieve this purpose, the present invention adopts the following technical solutions:

[0010] Provide a drying device for hazardous waste incineration slag, comprising:

[0011] A drying box, the drying box includes a box body and a jacket located on the outer periphery of the box body. A heating chamber for the circulation of a heating medium is formed between the jacket and the box body. The jacket is provided with an inlet and an outlet communicating with the heating chamber. The drying box is provided with a first avoidance hole and a second avoidance hole respectively penetrating through the jacket and the box body;

[0012] A belt conveying mechanism, including a plurality of belt conveyors. Along the conveying direction of the hazardous waste incineration slag, the output end of each belt conveyor located upstream is respectively directly above the input end of the belt conveyor located downstream; the input end of the belt conveyor located at the most upstream is located outside the drying box. This belt conveyor is inclined upward and its output end extends into the box body through the first avoidance hole; a plurality of belt conveyors located in the middle reaches are all located inside the box body; the input end of the belt conveyor located at the most downstream is located inside the box body. This belt conveyor is inclined downward and its output end extends outside the box body through the second avoidance hole;

[0013] A water collecting tank, located at the lower end of the box body and communicating with the box body. The water collecting tank has a sewage outlet;

[0014] An air collecting hood, the air collecting hood is installed on the top of the box body and communicates with the inside of the box body. The air collecting hood has an exhaust port.

[0015] As a preferred solution of the drying device for hazardous waste incineration slag, a plurality of belt conveyors located in the middle reaches are all inclined downward.

[0016] As a preferred solution of the hazardous waste incineration slag drying device, along the conveying direction of the hazardous waste incineration slag, the belt conveying mechanism includes a first belt conveyor, a second belt conveyor, a third belt conveyor, a fourth belt conveyor, a fifth belt conveyor and a sixth belt conveyor. The first belt conveyor is the belt conveyor located at the most upstream. The first belt conveyor and the second belt conveyor are in the same plane in the vertical plane. Among the second belt conveyor, the third belt conveyor, the fourth belt conveyor, the fifth belt conveyor and the sixth belt conveyor, the included angle between the vertical planes where every two adjacent belt conveyors are located is 75 - 120°.

[0017] As a preferred solution of the hazardous waste incineration slag drying device, the included angle is 90°.

[0018] As a preferred solution of the hazardous waste incineration slag drying device, the upward inclination angle of the first belt conveyor is 7 - 10°, the downward inclination angle of the second belt conveyor is 1 - 3°, the downward inclination angle of the third belt conveyor is 5 - 7°, the downward inclination angle of the fourth belt conveyor is 1 - 3°, the downward inclination angle of the fifth belt conveyor is 5 - 7°, and the downward inclination angle of the sixth belt conveyor is 1 - 3°.

[0019] As a preferred solution of the hazardous waste incineration slag drying device, the vertical planes of the third belt conveyor and the fifth belt conveyor are parallel, and the vertical planes of the second belt conveyor, the fourth belt conveyor and the sixth belt conveyor are parallel.

[0020] As a preferred solution of the hazardous waste incineration slag drying device, the conveying speed of the belt conveyor is 0.05 - 0.5 m / s.

[0021] As a preferred solution of the hazardous waste incineration slag drying device, it further includes a receiving box arranged adjacent to the drying box, and the receiving box is directly below the output end of the belt conveyor located at the most downstream.

[0022] The second object of the present invention is to provide an on - line drying system for hazardous waste incineration slag based on the above - mentioned hazardous waste incineration slag drying device. After the slag is discharged from the water - quenching slag - discharging machine, it does not go through bagging first, but is directly conveyed to the drying system and dried on - line by using the high - temperature incineration flue gas at the front end of the bag filter. The flue gas and the slag do not come into direct contact, and the volatilized moisture of the slag will not enter the flue gas to cause the situation of too high moisture content of the flue gas. When the flue gas is merged back to the front - end treatment of the bag filter, the situation of "bag sticking" will not occur, which effectively ensures the continuous and stable operation of the incineration system.

[0023] On the other hand, provide an on - line drying system for hazardous waste incineration slag based on the above - mentioned hazardous waste incineration slag drying device,

[0024] To achieve this purpose, the present invention adopts the following technical solutions:

[0025] An on-line drying system for hazardous waste incineration slag based on the above-mentioned hazardous waste incineration slag drying device, comprising:

[0026] A hazardous waste incineration flue gas treatment system, comprising a waste heat boiler, a quench tower, an activated carbon injection pipeline, and a bag filter connected in sequence through pipelines. The flue gas inlet of the waste heat boiler is connected to the flue gas outlet of the secondary combustion chamber through a pipeline, and the tail of the rotary kiln is located in the secondary combustion chamber;

[0027] A slag discharge machine, located below the slag discharge port of the rotary kiln, and the sewage discharge port of the water collection tank is connected to the slag discharge machine through a pipeline;

[0028] A hazardous waste incineration slag drying device, the slag discharge port of the slag discharge machine is directly above the input end of the belt conveyor at the uppermost stream of the hazardous waste incineration slag drying device. The pipelines for connecting the flue gas outlet of the quench tower and the inlet of the activated carbon injection pipeline are also respectively connected to the inlet and outlet of the jacket through pipelines. The exhaust port of the gas collection hood is connected to the pipeline for connecting the flue gas outlet of the bag filter and the flue gas inlet of the wet scrubber through a pipeline.

[0029] As a preferred scheme of the on-line drying system for hazardous waste incineration slag, the hazardous waste incineration flue gas treatment system further comprises a draft fan, a flue gas reheater, and a chimney. The air inlet of the draft fan is connected to the flue gas outlet of the wet scrubber through a pipeline, the air outlet of the draft fan is connected to the flue gas inlet of the flue gas reheater through a pipeline, and the flue gas outlet of the flue gas reheater is connected to the flue gas inlet of the chimney through a pipeline.

[0030] The beneficial effects of the present invention:

[0031] 1. The on-line drying system for hazardous waste incineration slag greatly saves the packaging, transportation, and landfill costs of the slag, realizing the reduction of the slag. At the same time, compared with the situation where the slag is cooled by falling and manually transported to a non-on-line drying system outside the incineration system, after the slag is discharged from the water quenching slag discharge machine, it does not go through bagging first, but is directly transported to the drying system for drying, realizing on-line drying, greatly saving labor consumption, improving the drying efficiency, and reducing the risk of secondary pollution.

[0032] 2. Using the high-temperature incineration flue gas in front of the bag filter for drying does not require additional steam injection, which is waste utilization and energy-saving; and the flue gas does not directly contact the slag, so the volatilized moisture of the slag will not enter the flue gas to cause the situation of too high moisture content in the flue gas. When the flue gas is returned to the front end of the bag filter for treatment, the situation of "bag sticking" of the bag filter will not occur, effectively ensuring the continuous and stable operation of the incineration system.

[0033] 3. The drying exhaust gas is introduced into the flue before the wet scrubbing system after the bag filter under the slightly negative pressure operation of the induced draft fan of the rotary kiln flue gas purification system, and enters the wet scrubbing system together with the flue gas for treatment without overflowing, and finally is discharged through the chimney.

[0034] 4. The goal of reducing the amount of hazardous waste incineration slag is achieved, which has good social, environmental and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0036] Figure 1 It is a schematic diagram of the hazardous waste incineration slag drying device (excluding the water collecting tank and the gas collecting hood) described in the embodiment of the present invention.

[0037] Figure 2 It is a schematic diagram of the on-line drying system for hazardous waste incineration slag described in the embodiment of the present invention.

[0038] In the figure:

[0039] 1. Drying box; 11. Box body; 12. Jacket; 13. Heating chamber; 2. Belt conveying mechanism; 21. First belt conveyor; 22. Second belt conveyor; 23. Third belt conveyor; 24. Fourth belt conveyor; 25. Fifth belt conveyor; 26. Sixth belt conveyor; 3. Water collecting tank; 4. Gas collecting hood; 5. Feeding box; 6. Hazardous waste incineration flue gas treatment system; 61. Waste heat boiler; 62. Quench tower; 63. Activated carbon injection pipeline; 64. Bag filter; 65. Wet scrubbing tower; 66. Induced draft fan; 67. Flue gas reheater; 68. Chimney; 7. Slag discharger. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] The technical solutions of the present invention will be further described below in conjunction with the drawings and specific embodiments.

[0041] Among them, the drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and should not be construed as a limitation of this patent; in order to better illustrate the embodiments of the present invention, some components in the drawings will be omitted, enlarged or reduced, which do not represent the dimensions of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0042] In the drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if terms such as "upper", "lower", "left", "right", "inner", "outer", etc. are used to indicate the orientation or positional relationship, such orientation or positional relationship is based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and cannot be construed as a limitation of this patent. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0043] In the description of the present invention, unless otherwise clearly specified and limited, if terms such as "connection" are used to indicate the connection relationship between components, this term should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] Embodiment 1

[0045] As Figure 1 shown, in this embodiment, the hazardous waste incineration slag drying device includes:

[0046] A drying box 1, the drying box 1 includes a box body 11 and a jacket 12 located on the outer periphery of the box body 11. A heating chamber 13 for the circulation of a heating medium is formed between the jacket 12 and the box body 11. The jacket 12 is provided with an inlet and an outlet communicating with the heating chamber 13. The drying box 1 is provided with a first avoidance hole and a second avoidance hole respectively penetrating through the jacket 12 and the box body 11;

[0047] A belt conveying mechanism 2, including a plurality of belt conveyors. Along the conveying direction of the hazardous waste incineration slag, the output end of each belt conveyor located upstream is respectively directly above the input end of its downstream belt conveyor; the input end of one belt conveyor located at the most upstream is located outside the drying box 1. This belt conveyor is inclined upward and its output end extends into the box body 11 through the first avoidance hole; a plurality of belt conveyors located in the middle reaches are all located in the box body 11; the input end of the belt conveyor located at the most downstream is located in the box body 11. This belt conveyor is inclined downward and its output end extends out of the box body 11 through the second avoidance hole;

[0048] A water collecting tank 3, located at the lower end of the box body 11 and communicating with the box body 11. The water collecting tank 3 has a sewage outlet;

[0049] A gas collecting hood 4, the gas collecting hood 4 is installed on the top of the box body 11 and is communicated with the inside of the box body 11, and the gas collecting hood 4 has an air outlet.

[0050] The belt conveying mechanism 2 effectively avoids the phenomenon that the large waste incineration furnace slag jams during the conveying process and causes damage to the belt conveyor.

[0051] In this embodiment, a heating medium is used to flow in the heating chamber 13, and the waste incineration furnace slag conveyed by the belt conveyor in the box body 11 is subjected to non-contact heat exchange through the heating medium. The heated heating medium flows out from the outlet; the waste gas generated during the drying process of the waste incineration furnace slag on the belt conveyor is collected by the gas collecting hood 4 at the upper end of the drying box 1 and discharged to the next process. The water collecting tank 3 is used to collect the water leaked during the drying process of the waste incineration furnace slag and is discharged to the next process through the sewage outlet to avoid sewage overflow. The waste incineration furnace slag falls into the next process after being dried by the drying box 1. In this embodiment, multiple belt conveyors are used for transfer to increase the residence time of the waste incineration furnace slag, so that the waste incineration furnace slag is in full contact with the heat source. The number of belt conveyors is determined by the on-site height, or can be determined by calculating the residence time of the material drying based on the final moisture content of the waste incineration furnace slag.

[0052] Among them, the positions of the jacket 12 at the first avoidance hole and the second avoidance hole are both sealed. The sizes of the first avoidance hole and the second avoidance hole are appropriate for the smooth passage of the belt conveyor for conveying the waste incineration furnace slag, and are not specifically limited.

[0053] Among them, the term "the belt conveyor is inclined upward" means that the output end of the belt conveyor is higher than its input end. The term "several of the belt conveyors located in the middle reaches" refers to all the belt conveyors between the belt conveyor located at the uppermost reaches and the belt conveyor located at the lowermost reaches.

[0054] In this embodiment, the belt of the belt conveyor is heat-resistant, with a temperature resistance ≤ 500°C, and is driven by an electric roller (explosion-proof) and frequency-controlled, and can control the conveying speed to be 0.05 - 0.5 m / s. The box body 11 of the drying box 1 is made of welded parts such as angle irons, square tubes, and steel plates welded together to form a cuboid structure, which is communicated with the gas collecting hood 4 at the upper end and the water collecting tank 3 at the lower end. The jacket 12 is hermetically connected to the upper end and the lower end of the box body 11 respectively.

[0055] In this embodiment, several of the belt conveyors located in the middle reaches are all inclined downward, that is, the height of the input end of the belt conveyor is higher than the height of the output end of the belt conveyor, so that the waste incineration furnace slag on the belt conveyor can fall onto the next belt conveyor downstream under the action of its own gravity.

[0056] Specifically, along the conveying direction of the hazardous waste incineration slag, the belt conveying mechanism 2 includes a first belt conveyor 21, a second belt conveyor 22, a third belt conveyor 23, a fourth belt conveyor 24, a fifth belt conveyor 25, and a sixth belt conveyor 26. The first belt conveyor 21 is the belt conveyor located at the uppermost stream. The first belt conveyor 21 and the second belt conveyor 22 are in the same plane in the vertical plane. Among the second belt conveyor 22, the third belt conveyor 23, the fourth belt conveyor 24, the fifth belt conveyor 25, and the sixth belt conveyor 26, the included angles between the vertical planes where every two adjacent belt conveyors are located are respectively 75 - 120°, preferably 90°. By designing the other belt conveyors except the first belt conveyor 21 to have an included angle of 90°, the space of the box body 11 of the drying box 1 can be fully utilized. Among them, the mounting brackets of the second belt conveyor 22, the third belt conveyor 23, the fourth belt conveyor 24, and the fifth belt conveyor 25 are respectively fixedly connected to the inner side wall of the box body 11, and details are not described herein again. The mounting brackets of the first belt conveyor 21 and the sixth belt conveyor 26 are partially located inside the box body 11 and fixedly connected to the inner side wall of the box body 11, and partially located outside the box body 12 and supported on the ground. Each belt conveyor is a conventional technology in the art, and details are not described herein again.

[0057] Among them, the term "vertical plane" refers to the plane in the vertical direction with one side of the belt of the belt conveyor along its width direction as the reference.

[0058] Further, the upward inclination angle of the first belt conveyor 21 is 7 - 10°, the downward inclination angle of the second belt conveyor 22 is 1 - 3°, the downward inclination angle of the third belt conveyor 23 is 5 - 7°, the downward inclination angle of the fourth belt conveyor 24 is 1 - 3°, the downward inclination angle of the fifth belt conveyor 25 is 5 - 7°, and the downward inclination angle of the sixth belt conveyor 26 is 1 - 3°.

[0059] Furthermore, the vertical planes of the third belt conveyor 23 and the fifth belt conveyor 25 are parallel, and the vertical planes of the second belt conveyor 22, the fourth belt conveyor 24, and the sixth belt conveyor 26 are parallel.

[0060] In this embodiment, the hazardous waste incineration slag drying device further includes a receiving box 5 disposed adjacent to the drying box 1. The receiving box 5 is directly below the output end of the belt conveyor at the lowermost stream. After the hazardous waste incineration slag on the belt conveyor at the lowermost stream is conveyed to the output end, it falls into the receiving box 5 by its own gravity.

[0061] This embodiment also provides an on-line drying system for hazardous waste incineration slag based on the above-mentioned hazardous waste incineration slag drying device, including:

[0062] A hazardous waste incineration flue gas treatment system 6, including a waste heat boiler 61, a quench tower 62, an activated carbon injection pipeline 63, a bag filter 64, and a wet scrubber 65 connected in sequence through pipelines. The flue gas inlet of the waste heat boiler 61 is connected to the flue gas outlet of the secondary combustion chamber through a pipeline, and the tail of the rotary kiln is located in the secondary combustion chamber;

[0063] A slag discharger 7, located below the slag discharge port of the rotary kiln. The sewage outlet of the water collecting tank 3 is connected to the slag discharger 7 through a pipeline, and the slag discharger 7 uses a chain plate type slag conveyor;

[0064] A hazardous waste incineration slag drying device. The slag discharge port of the slag discharger 7 is directly above the input end of the belt conveyor at the most upstream of the hazardous waste incineration slag drying device. The pipelines for connecting the flue gas outlet of the quench tower 62 and the inlet of the activated carbon injection pipeline 63 are respectively connected to the inlet and outlet of the jacket 12 through pipelines. The exhaust port of the gas collecting hood 4 is connected to the pipeline for connecting the flue gas outlet of the bag filter 64 and the flue gas inlet of the wet scrubber 65 through a pipeline.

[0065] Among them, the slag discharger 7 discharges slag continuously, and the first belt conveyor 21 transports continuously. Compared with the batch charging method, the continuous slag discharging method can reduce problems such as excessive accumulation of hazardous waste incineration slag and insufficient contact with the heat source.

[0066] Among them, the hazardous waste incineration flue gas treatment system 6 also includes a draft fan 66, a flue gas reheater 67, and a chimney 68. The air inlet of the draft fan 66 is connected to the flue gas outlet of the wet scrubber 65 through a pipeline. The air outlet of the draft fan 66 is connected to the flue gas inlet of the flue gas reheater 67 through a pipeline. The flue gas outlet of the flue gas reheater 67 is connected to the flue gas inlet of the chimney 68 through a pipeline.

[0067] In this embodiment, the hazardous waste incineration flue gas treatment system 6 uses globally prevalent and mature technologies. For example, according to the Reply of Zhangzhou Environmental Protection Bureau on the Environmental Impact Report of Zhangzhou Industrial Waste Disposal and Utilization Center and Supporting Hazardous Waste Innocuous Landfill Project of Fujian Chuxin Environmental Protection Technology Co., Ltd. (Zhanghuan Shen

[2017] No. 13) approved by Zhangzhou Environmental Protection Bureau on August 15, 2017, the incinerator flue gas is treated by SNCR denitrification + waste heat boiler + quenching device + slaked lime and activated carbon injection (dry acid removal) + bag filter + wet acid removal + wet electrostatic demisting + flue gas reheating + SCR (reserved). After reaching the standard, it is discharged through a 50-meter-high chimney. Another example is that according to the Reply on the Environmental Impact Report of Jining Mingde Environmental Protection Technology Co., Ltd.'s Jining Industrial Waste Disposal Center (Jihuan Shen

[2018] No. 13) approved by Jining Environmental Protection Bureau on June 19, 2018, the incineration flue gas is treated by "high-temperature denitrification + cyclone dust removal + quenching tower + dry acid removal + activated carbon injection + bag dust removal + washing and demisting tower (wet acid removal) + flue gas heater". The tail gas is discharged through a 60m-high exhaust stack. Details are not elaborated here.

[0068] The heating medium (heat source) used for drying the hazardous waste incineration slag comes from the hazardous waste incineration flue gas. The upper gas collection hood 4 of the drying box 1 is connected to the pipeline before the wet scrubber 65. The drying exhaust gas is introduced into the pipeline connecting the bag filter 64 and the wet scrubber 65 through the induced draft fan 66 of the hazardous waste incineration flue gas treatment system 6 under slightly negative pressure operation, and enters the wet scrubber 65 for treatment together with the flue gas without overflowing, and finally is discharged through the chimney, making full use of the hazardous waste incineration flue gas.

[0069] The volatile moisture of the hazardous waste incineration slag will not enter the flue gas to cause too high moisture content of the flue gas, and the situation of "bag sticking" will not occur when the flue gas is merged back to the front end of the bag filter 64 for treatment, effectively ensuring the continuous and stable operation of the incineration system.

[0070] The overall structure of the entire on-line drying system for hazardous waste incineration slag is simple and has good integrity. It can reduce the moisture content of the slag with a moisture content of about 30 - 40% to about 5 - 10% in a short time, and the drying efficiency is relatively high.

[0071] As a specific embodiment of the present invention, the height of the slag discharge port of the slag discharger 7 is 2.0 m, the total length of the belt of the first belt conveyor 21 is 10.0 m, the installation height of the input end is 1.8 m, and the installation height of the output end is 3.2 m; the total length of the second belt conveyor 22 is 6.0 m, the installation height of the input end is 3.0 m, and the installation height of the output end is 2.8 m; the total length of the third belt conveyor 23 is 2.0 m, the installation height of the input end is 2.6 m, and the installation height of the output end is 2.4 m; the total length of the fourth belt conveyor 24 is 6.0 m, the installation height of the input end is 2.2 m, and the installation height of the output end is 2.0 m; the total length of the fifth belt conveyor 25 is 2.0 m, the installation height of the input end is 1.8 m, and the installation height of the output end is 1.6 m; the total length of the sixth belt conveyor 26 is 7.0 m, the installation height of the input end is 1.4 m, and the installation height of the output end is 1.2 m.

[0072] In this embodiment, the moisture content of the hazardous waste incineration slag when it is discharged from the slag discharge port of the rotary kiln is 35%. The specific process of online drying of the hazardous waste incineration slag using the online drying system for hazardous waste incineration slag of the present invention is as follows:

[0073] The hazardous waste incineration slag falls from the tail of the rotary kiln into the lower slag discharger 7, and the slag discharger 7 uses a chain plate type for slag transportation. A first belt conveyor 21 for lifting is arranged below the slag discharge port of the slag discharger 7. The hazardous waste incineration slag falls from the slag discharge port of the slag discharger 7 into the input end of the first belt conveyor 21 for lifting, which is located outside the drying box 1, by the action of gravity, and is transported to the output end of the first belt conveyor 21 through the first belt conveyor 21, and then falls into the input end of the second belt conveyor 22 located inside the drying box 1 by the action of gravity; the second belt conveyor 22 transports the hazardous waste incineration slag from the input end of the second belt conveyor 22 to the output end of the second belt conveyor 22, and then falls into the input end of the third belt conveyor 23 located inside the drying box 1 by the action of gravity; the third belt conveyor 23 transports the hazardous waste incineration slag from the input end of the third belt conveyor 23 to the output end of the third belt conveyor 23, and then falls into the input end of the fourth belt conveyor 24 located inside the drying box 1 by the action of gravity; the fourth belt conveyor 24 transports the hazardous waste incineration slag from the input end of the fourth belt conveyor 24 to the output end of the fourth belt conveyor 24, and then falls into the input end of the fifth belt conveyor 25 located inside the drying box 1 by the action of gravity; the fifth belt conveyor 25 transports the hazardous waste incineration slag from the input end of the fifth belt conveyor 25 to the output end of the fifth belt conveyor 25, and then falls into the input end of the sixth belt conveyor 26 located inside the drying box 1 by the action of gravity; the sixth belt conveyor 26 transports the hazardous waste incineration slag from the input end of the sixth belt conveyor 26 to the output end of the sixth belt conveyor 26 located outside the drying box 1, and finally falls into the receiving box 5 by the action of gravity; among them, the conveying speed of all belt conveyors is 0.1 m / s. The hazardous waste incineration slag stays in the drying box 1 for 220 s, and the moisture content of the dried hazardous waste incineration slag drops to 10%.

[0074] After coming out of the rotary kiln, the hazardous waste incineration flue gas is successively treated by a waste heat boiler 61, a quench tower 62 (the flue gas temperature at the outlet end is 220 °C), an activated carbon injection pipeline 63, a bag filter 64, and a wet scrubber 65, and then is introduced into a flue gas reheater 67 through a induced draft fan 66 and discharged through a chimney 68. Part of the flue gas coming out of the quench tower 62 enters the jacket 12 of the drying box 1 to conduct non-contact drying on the hazardous waste incineration slag inside the drying box 1. After heat exchange, it returns to the pipeline at the outlet end of the quench tower 62 through the outlet of the jacket 12 and is merged with the original flue gas for transportation to the bag filter 64 for treatment; the waste gas generated during the drying process of the hazardous waste incineration slag inside the box body 11 of the drying box 1 is collected in the gas collecting hood 4 and is transported to the pipeline between the bag filter 64 and the wet scrubber 65 under the action of the slightly negative pressure of the induced draft fan 66, and is merged with the original flue gas for transportation to the wet scrubber 65 for treatment.

[0075] Example 2

[0076] The on-line drying system for hazardous waste incineration slag in this embodiment is basically the same as that in the first embodiment above, except that a seventh belt conveyor is added. The second, third, fourth, fifth, and sixth belt conveyors are all located inside the drying box. Except for the first belt conveyor, the vertical planes where adjacent two belt conveyors are located form an angle of 90° respectively. The output end of the seventh belt conveyor extends outside the drying box 1.

[0077] In this embodiment, the conveying speed of all belts is 0.1 m / s. The total length of the first belt conveyor is 12.0 m, the installation height of the input end is 1.8 m, and the installation height of the output end is 3.6 m; the total length of the second belt conveyor is 6.0 m, the installation height of the input end is 3.4 m, and the installation height of the output end is 3.2 m; the total length of the third belt conveyor is 2.0 m, the installation height of the input end is 3.0 m, and the installation height of the output end is 2.8 m; the total length of the fourth belt conveyor is 6.0 m, the installation height of the input end is 2.6 m, and the installation height of the output end is 2.4 m; the total length of the fifth belt conveyor is 2.0 m, the installation height of the input end is 2.2 m, and the installation height of the output end is 2.0 m; the total length of the sixth belt conveyor is 6.0 m, the installation height of the input end is 1.8 m, and the installation height of the output end is 1.6 m; the total length of the seventh belt conveyor is 3.0 m, the installation height of the input end is 1.4 m, and the installation height of the output end is 1.2 m.

[0078] Using the on-line drying system for hazardous waste incineration slag in this embodiment to dry the hazardous waste incineration slag with an initial water content of 38%, the hazardous waste incineration slag stays in the drying box for 240 s, and the water content of the dried hazardous waste incineration slag drops to 10%.

[0079] Embodiment Three

[0080] The on-line drying system for hazardous waste incineration slag in this embodiment is basically the same as that in the second embodiment above, except for the installation positions of the belt conveyors in the belt conveying mechanism. The conveying speed of all belts is 0.05 m / s. The total length of the first belt conveyor is 12.0 m, the installation height of the input end is 1.8 m, and the installation height of the output end is 3.6 m; the total length of the second belt conveyor is 8.0 m, the installation height of the input end is 3.4 m, and the installation height of the output end is 3.2 m; the total length of the third belt conveyor is 4.0 m, the installation height of the input end is 3.0 m, and the installation height of the output end is 2.8 m; the total length of the fourth belt conveyor is 8.0 m, the installation height of the input end is 2.6 m, and the installation height of the output end is 2.4 m; the total length of the fifth belt conveyor is about 4.0 m, the installation height of the input end is 2.2 m, and the installation height of the output end is 2.0 m; the total length of the sixth belt conveyor is 8.0 m, the installation height of the input end is 1.8 m, and the installation height of the output end is 1.6 m; the total length of the seventh belt conveyor is about 5.0 m, the installation height of the input end is 1.4 m, and the installation height of the output end is 1.2 m.

[0081] The online drying system for hazardous waste incineration slag of this embodiment is used to dry the hazardous waste incineration slag with an initial water content of 40%. The hazardous waste incineration slag stays in the drying box for 720 s, and the water content of the dried hazardous waste incineration slag drops to 5%.

[0082] It should be noted that the above specific implementation manners are only the preferred embodiments of the present invention and the applied technical principles. Those skilled in the art should understand that various modifications, equivalent replacements, changes, etc. can be made to the present invention. However, as long as these transformations do not deviate from the spirit of the present invention, they should be within the protection scope of the present invention. In addition, some terms used in the specification and claims of this application are not restrictive, but are only for the convenience of description.

Claims

1. An on-line drying system for hazardous waste incineration slag, characterized in that, Comprising: A hazardous waste incineration flue gas treatment system, including a waste heat boiler, a quench tower, an activated carbon injection pipeline, a bag filter, and a wet scrubber connected in sequence through pipelines. The flue gas inlet of the waste heat boiler is connected to the flue gas outlet of the secondary combustion chamber through a pipeline, and the tail of the rotary kiln is located inside the secondary combustion chamber; A slag discharge machine, located below the slag discharge port of the rotary kiln, and the sewage discharge port of the water collection tank is connected to the slag discharge machine through a pipeline; A hazardous waste incineration slag drying device, including: A drying box, which includes a box body and a jacket located on the periphery of the box body. A heating chamber for the circulation of a heating medium is formed between the jacket and the box body. The jacket is provided with an inlet and an outlet communicating with the heating chamber. The drying box is provided with a first avoidance hole and a second avoidance hole respectively penetrating through the jacket and the box body; A belt conveying mechanism, including a number of belt conveyors. Along the conveying direction of the hazardous waste incineration slag, the output end of each belt conveyor located upstream is respectively directly above the input end of its downstream belt conveyor; the input end of the belt conveyor located at the most upstream is located outside the drying box. This belt conveyor is inclined upward and its output end extends into the box body through the first avoidance hole; a number of belt conveyors located in the middle reaches are all located inside the box body; the input end of the belt conveyor located at the most downstream is located inside the box body. This belt conveyor is inclined downward and its output end extends outside the box body through the second avoidance hole; A water collection tank, located at the lower end of the box body and communicating with the box body, and the water collection tank has a sewage discharge port; An air collection hood, which is installed on the top of the box body and communicates with the inside of the box body, and the air collection hood has an exhaust port; The slag discharge port of the slag discharge machine is directly above the input end of the belt conveyor located at the most upstream. The pipelines for connecting the flue gas outlet of the quench tower and the inlet of the activated carbon injection pipeline are also respectively connected to the inlet and outlet of the jacket through pipelines. The exhaust port of the air collection hood is connected to the pipeline for connecting the flue gas outlet of the bag filter and the flue gas inlet of the wet scrubber through a pipeline.

2. The on-line drying system for hazardous waste incineration slag according to claim 1, characterized in that, A number of belt conveyors located in the middle reaches are all inclined downward.

3. The online drying system for hazardous waste incineration slag according to claim 2, wherein Along the conveying direction of the hazardous waste incineration slag, the belt conveying mechanism includes a first belt conveyor, a second belt conveyor, a third belt conveyor, a fourth belt conveyor, a fifth belt conveyor, and a sixth belt conveyor. The first belt conveyor is the belt conveyor located at the most upstream. The first belt conveyor and the second belt conveyor are in the same plane in the vertical direction. Among the second belt conveyor, the third belt conveyor, the fourth belt conveyor, the fifth belt conveyor, and the sixth belt conveyor, the included angle between the vertical planes where every two adjacent belt conveyors are located is 75 - 120°.

4. The on-line drying system for hazardous waste incineration slag according to claim 3, characterized in that, The included angle is 90°.

5. The on-line drying system for hazardous waste incineration slag according to claim 3, characterized in that, The upward inclination angle of the first belt conveyor is 7 to 10°, the downward inclination angle of the second belt conveyor is 1 to 3°, the downward inclination angle of the third belt conveyor is 5 to 7°, the downward inclination angle of the fourth belt conveyor is 1 to 3°, the downward inclination angle of the fifth belt conveyor is 5 to 7°, and the downward inclination angle of the sixth belt conveyor is 1 to 3°.

6. The on-line drying system for hazardous waste incineration slag according to claim 5, characterized in that, The third belt conveyor is parallel to the vertical plane of the fifth belt conveyor, and the second belt conveyor, the fourth belt conveyor, and the sixth belt conveyor are parallel to the vertical plane.

7. The on-line drying system for hazardous waste incineration slag according to claim 1, characterized in that The conveying speed of the belt conveyor is 0.05 - 0.5 m / s.

8. The on-line drying system for hazardous waste incineration slag according to claim 1, characterized in that The hazardous waste incineration slag drying device further includes a receiving box disposed adjacent to the drying box, and the receiving box is directly below the output end of the belt conveyor located at the most downstream.

9. The on-line drying system for hazardous waste incineration slag according to any one of claims 1 to 8, characterized in that, The hazardous waste incineration flue gas treatment system further includes an induced draft fan, a flue gas reheater, and a chimney. The air inlet of the induced draft fan is connected to the flue gas outlet of the wet scrubber through a pipeline, the air outlet of the induced draft fan is connected to the flue gas inlet of the flue gas reheater through a pipeline, and the flue gas outlet of the flue gas reheater is connected to the flue gas inlet of the chimney through a pipeline.

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