Pyrolysis system applied to harmlessness of chemical waste salt

Abstract

The utility model relates to the field of chemical waste salt pyrolysis treatment equipment, in particular to a pyrolysis system applied to harmlessness of chemical waste salt, which comprises a mixing bin and a carbonization device which are connected with each other, and the carbonization device is provided with a flue gas outlet and a material outlet. The flue gas outlet is connected with a quench tower, and the quench tower is connected with the dry-process deacidification denitration tower through a high-temperature ceramic filter dust remover; the material outlet is connected with a cooling device, and the cooling device is connected with a finished product bin through a spiral conveyor; the chemical waste salt treatment device is simple in structure, energy-saving, environment-friendly, stable in operation and capable of carrying out innocent treatment on chemical waste salt.

Description

Technical Field

[0001] The utility model relates to the field of chemical waste salt pyrolysis treatment equipment, and particularly relates to a pyrolysis system applied to the harmless treatment of chemical waste salt. Background Art

[0002] Pyrolysis technology is an effective method for treating waste salt. It decomposes waste salt into harmless substances through high-temperature reactions, reducing the environmental pollution caused by waste salt. By treating waste salt with pyrolysis technology, the discharge of waste salt can be reduced, useful components in the waste salt can be extracted, the resource utilization of waste salt can be realized, resource waste can be reduced, and the impact on the environment can be lowered. The existing pyrolysis carbonization process technology has high energy consumption and is prone to generating toxic and harmful substances such as dioxins. The equipment used is also prone to problems such as adhesion and material discharge blockage during operation. Therefore, the harmless treatment of waste salt in industrial production has not been fully promoted.

[0003] CN220771126U discloses a segmented industrial waste salt harmless treatment device for efficiently removing organic substances, heavy metals, dioxins and other toxic substances in industrial waste salt. The device conveys and feeds materials through a screw conveyor to achieve sufficient mixing and combustion of materials in a pyrolysis carbonization furnace and a high-temperature melting furnace. However, the two heat treatment areas in the segmented design are relatively large, resulting in high energy consumption. Summary of the Utility Model

[0004] In order to solve the above problems, the utility model provides a pyrolysis system applied to the harmless treatment of chemical waste salt, which has a simple structure, is energy-saving and environmentally friendly, can operate stably, can perform harmless treatment on chemical waste salt, and has good treatment effects.

[0005] A pyrolysis system applied to the harmless treatment of chemical waste salt of the utility model includes a mixing bin and a carbonization device connected to each other. A flue gas outlet and a material outlet are arranged on the carbonization device. A quenching tower is connected to the flue gas outlet. The quenching tower is connected to a dry desulfurization, denitrification and deacidification tower through a high-temperature ceramic filter dust collector;

[0006] A cooling device is connected to the material outlet. The cooling device is connected to a finished product bin through a screw conveyor;

[0007] The temperature of the flue gas at the outlet of the quenching tower is not higher than 250°C.

[0008] Preferably, the mixing bin is connected to the carbonization device through a screw conveyor.

[0009] Preferably, a crusher is further connected to the mixing bin. The discharge port on the crusher is hermetically connected to the feed port on the mixing bin.

[0010] Preferably, the cooling device is a three-stage cooling circulating water jacket.

[0011] Alternatively, preferably, the carbonization device includes a bracket, on which a heat preservation chamber and a combustion chamber are fixedly arranged, and the inside of the heat preservation chamber communicates with the combustion chamber; the flue gas outlet is arranged on the combustion chamber;

[0012] A carbonization chamber is fixedly arranged inside the heat preservation chamber. A feed inlet is arranged at one end of the carbonization chamber, and a discharge outlet is arranged at the other end of the carbonization chamber. A discharge channel is connected to the discharge outlet, and the material outlet is arranged at one end of the discharge channel far away from the carbonization chamber, and the material outlet extends out of the heat preservation chamber;

[0013] A material transmission device for driving the material to move from the feed inlet towards the discharge outlet is arranged inside the carbonization chamber.

[0014] Preferably, two carbonization chambers are provided, and the two carbonization chambers are arranged overlapping up and down, and the combustion chamber is located above the carbonization chamber;

[0015] The two ends of the two carbonization chambers are respectively connected by a connecting pipe; valves are arranged on the connecting pipes.

[0016] Preferably, two material transmission devices are arranged side by side inside the carbonization chamber.

[0017] Preferably, the material transmission device includes a conveying shaft, and the two ends of the conveying shaft are respectively rotationally connected to the carbonization chamber through bearings; spiral conveying blades are arranged on the conveying shaft;

[0018] One end of the conveying shaft extends out of the carbonization chamber and is connected to a driving motor, and the conveying shaft is hermetically connected to the carbonization chamber;

[0019] The driving motor is fixedly arranged on the bracket.

[0020] Preferably, the spiral conveying blades of the material transmission devices in the same carbonization chamber are arranged in a staggered manner.

[0021] The utility model has a simple structure, is energy-saving and environment-friendly, can operate stably, and can harmlessly treat chemical waste salts.

[0022] The utility model carbonizes the material under anoxic conditions, has low energy consumption, can stably remove the organic matter in the waste salt material, does not produce toxic substances, and its pyrolysis heat source comes from the pyrolysis gas that first undergoes the first active combustion in the first-stage internal combustion chamber, and the generated heat energy is used reversely for carbonization heating. If the organic components in the disposed material are sufficient, the heat energy generated by the combustion of the pyrolysis gas can realize the self-sustaining operation of the carbonization process, saving energy to the greatest extent. The pyrolysis carbonization temperature is high and can be accurately controlled. The working temperature inside the carbonization cavity is generally 650 °C and above, avoiding the generation temperature range of highly toxic substances such as dioxins and furans, which is 250 - 500 °C. The reason is that the carbonization cavity is in an oxygen-free environment, and the organic matter is in a reduced state throughout the disposal process, that is, the generation of highly toxic substances such as dioxins and furans is suppressed in principle, and no highly toxic substances such as dioxins and furans are generated during the carbonization process.

[0023] The carbonization device of the utility model is provided with a double - helix conveyor, ensuring that the material is not completely static during the process of entering the carbonization chamber for carbonization. During the rotation process, the spiral blades have a loosening effect on the material, making it not easy to agglomerate, and the heating process is more uniform. During the operation of the equipment, no inert gas is required to drive out oxygen. It can not only ensure that oxygen is isolated from entering the carbonization cavity during the feeding and discharging processes under high - temperature working conditions, but also extract the air doped in the solid raw materials before entering the carbonization cavity, ensuring that the oxygen content during the carbonization process is at the lowest level. Brief Description of the Drawings

[0024] Figure 1 It is a schematic diagram of the utility model.

[0025] Figure 2 It is a schematic structural diagram of the carbonization device of the utility model after removing the driving motor.

[0026] Reference Numerals: 1 - support, 2 - insulation chamber, 3 - combustion chamber, 4 - material transmission device, 5 - flue gas outlet, 6 - carbonization chamber. Detailed Embodiment

[0027] The following is an explanation of the utility model in conjunction with Figure 1 and Figure 2 the attached drawings. Referring to Figure 1 , a pyrolysis system for the harmless treatment of chemical waste salts of the utility model includes a mixing bin and a carbonization device connected to each other. The carbonization device is provided with a flue gas outlet 5 and a material outlet. A quench tower is connected to the flue gas outlet 5, and the quench tower is connected to a dry - method deacidification and denitrification tower through a high - temperature ceramic filter dust collector;

[0028] A cooling device is connected to the material outlet, and the cooling device is connected to a finished product bin through a screw conveyor;

[0029] The flue gas temperature at the outlet of the quench tower is not higher than 250 °C.

[0030] The mixing bin is connected to the carbonization device through a screw conveyor.

[0031] A crusher is also connected to the mixing bin, and the discharge port of the crusher is hermetically connected to the feed port of the mixing bin.

[0032] The cooling device is a three - stage cooling circulating water jacket.

[0033] As Figure 2 shown, the carbonization device includes a support 1. An insulation chamber 2 and a combustion chamber 3 are fixedly arranged on the support 1, and the inside of the insulation chamber 2 is communicated with the combustion chamber 3; the flue gas outlet 5 is arranged on the combustion chamber 3;

[0034] A carbonization chamber 6 is fixedly arranged in the heat preservation chamber 2. A feed inlet is arranged at one end of the carbonization chamber 6, and a discharge outlet is arranged at the other end of the carbonization chamber 6. A discharge channel is connected to the discharge outlet, and the material outlet is arranged at one end of the discharge channel far away from the carbonization chamber 6, and the material outlet extends out of the heat preservation chamber 2;

[0035] A material transmission device 4 for driving the material to move from the feed inlet towards the discharge outlet is arranged in the carbonization chamber 6.

[0036] There are two carbonization chambers 6, and the two carbonization chambers 6 are arranged overlapping up and down, and the combustion chamber 3 is located above the carbonization chamber 6;

[0037] The two ends of the two carbonization chambers 6 are respectively connected by a connecting pipe; valves are arranged on the connecting pipes.

[0038] Two material transmission devices 4 are arranged in parallel in the carbonization chamber 6.

[0039] The material transmission device 4 includes a conveying shaft, and the two ends of the conveying shaft are respectively rotationally connected to the carbonization chamber 6 through bearings; spiral conveying blades are arranged on the conveying shaft;

[0040] One end of the conveying shaft extends out of the carbonization chamber 6 and is connected with a driving motor, and the conveying shaft is hermetically connected to the carbonization chamber 6;

[0041] The driving motor is fixedly arranged on the bracket 1.

[0042] The spiral conveying blades of the material transmission devices 4 in the same carbonization chamber 6 are arranged in a staggered manner.

[0043] During use, the waste salt is put into a pulverizer and pulverized to about 800 meshes. The outlet of the pulverizer is connected to a closed tube chain conveyor and conveyed into a mixing bin, and then conveyed into the carbonization device through a quantitative screw conveyor at the bottom of the mixing bin. The waste salt stays in the carbonization device for about 30 - 35 minutes to remove TOC, and after being discharged from the carbonization device, it is cooled to room temperature by a three-stage circulating water jacket and then collected.

[0044] The high-temperature flue gas discharged from the carbonization device is cooled rapidly, dust-removed, deacidified and denitrified, and then discharged up to the standard through a chimney.

[0045] During the carbonization process, due to anaerobic and high-temperature conditions, no highly toxic substances such as dioxins or furans will be produced. However, to prevent the secondary synthesis of dioxins or furans in the flue gas, the discharged flue gas must pass through a quench tower to reduce the flue gas temperature from 550 - 800 °C to 250 °C and below within 1 second.

[0046] Before entering the carbonization device, the chemical industrial waste salt is pretreated by dehydration, crushing, granulation, etc. according to physical parameters such as the form of the waste salt, moisture content, particle size, etc., and then enters the carbonization chamber 6 in the carbonization device in a quantitative conveying manner. In the oxygen-free environment in the carbonization chamber 6, the oxygen content is generally controlled within 0.2%. The indirect heating means that the treated material does not come into contact with an open flame, and the carbonization temperature is determined according to the characteristics of the treated material.

[0047] In the high-temperature oxygen-free environment, the organic components in the treated material are completely pyrolyzed into water vapor, non-condensable combustible small molecule gases and carbon particles under the action of dry distillation and pyrolysis. The water vapor and non-condensable gases are mixed to form pyrolysis gas, which is discharged from the carbonization chamber 6 and automatically diverted into the internal combustion chamber in the carbonization device. The internal combustion chamber is integrated with the carbonization cavity to form a larger sealed cavity, that is, it includes the carbonization chamber 6 and the combustion chamber 3, and full combustion is carried out.

[0048] Before feeding the carbonization device, it must be preheated to the reaction temperature of 500 °C and can operate continuously for 24 hours. The crushed chemical industrial waste salt is conveyed into the mixing bin through a tube chain. A variable-frequency anti-arching motor is configured in the mixing bin. The waste salt is conveyed into the carbonization device through a quantitative screw conveyor at the bottom of the bin for 30 - 35 minutes of carbonization treatment to remove TOC. Among them, the pyrolysis gas generated by carbonization is burned twice in the built-in two-stage combustion chamber 3, and the residence time is not less than two seconds. The heat generated provides heat for the carbonization of the subsequent treated material. The waste salt generated by carbonization is discharged out of the furnace and then enters a three-stage cooling device. After being cooled to below 50 °C, it is conveyed to the finished product bin through a screw conveyor. A anti-arching motor and a blanking device are configured in the finished product bin to facilitate the collection and packaging in ton bags;

[0049] The temperature of the flue gas discharged from carbonization is 550 - 800 °C, and the flue gas volume is < 700 Nm3 / h. It is first rapidly cooled to 250 °C or below, and then the salt powder and pre-denitrification in the flue gas are removed through a high-temperature resistant ceramic fiber filter. After that, sulfur oxides and nitrogen oxides are further removed through a dry denitrification and deacidification tower before reaching the standard for emission.

Claims

1. A pyrolysis system for harmless treatment of chemical waste salt, comprising a mixing bin and a carbonization device connected to each other, characterized in that: The carbonization device is provided with a flue gas outlet and a material outlet, the flue gas outlet is connected to a quenching tower, and the quenching tower is connected to a dry deacidification and denitration tower through a high-temperature ceramic filter dust collector; The material outlet is connected to a cooling device, and the cooling device is connected to the finished product silo through a screw conveyor; The flue gas temperature at the outlet of the quench tower is not higher than 250°C.

2. A pyrolysis system for harmless treatment of chemical waste salt as claimed in claim 1, characterized in that: The mixing bin is connected to the carbonization device through a screw conveyor.

3. A pyrolysis system for harmless treatment of chemical waste salt as claimed in claim 1, characterized in that: The mixing bin is also connected with a pulverizer, and the discharge port on the pulverizer is sealed and connected with the feed port on the mixing bin.

4. A pyrolysis system for harmless treatment of chemical waste salt as claimed in claim 1, characterized in that: The cooling device is a three-stage cooling circulation water jacket.

5. A pyrolysis system for harmless treatment of chemical waste salt as claimed in any one of claims 1 to 4, characterized in that: The carbonization device comprises a bracket, on which a heat preservation chamber and a combustion chamber are fixedly arranged, and the heat preservation chamber is communicated with the combustion chamber; the smoke outlet is arranged on the combustion chamber; A carbonization chamber is fixedly arranged in the insulation chamber, a feed port is arranged at one end of the carbonization chamber, a discharge port is arranged at the other end of the carbonization chamber, a discharge channel is connected to the discharge port, the material outlet is arranged at one end of the discharge channel away from the carbonization chamber, and the material outlet extends out of the insulation chamber; The carbonization chamber is provided with a material transmission device for driving the material to move from the feed port toward the discharge port.

6. A pyrolysis system for harmless treatment of chemical waste salt as claimed in claim 5, characterized in that: Two carbonization chambers are provided, the two carbonization chambers are arranged overlapping each other, and the combustion chamber is located at the upper part of the carbonization chamber; The two ends of the carbonization chamber are connected through connecting pipes respectively; valves are arranged on the connecting pipes.

7. A pyrolysis system for harmless treatment of chemical waste salt as claimed in claim 6, characterized in that: Two material transmission devices are arranged in parallel in the carbonization chamber.

8. A pyrolysis system for harmless treatment of chemical waste salt as claimed in claim 7, characterized in that: The material transmission device comprises a conveying shaft, both ends of which are rotatably connected to the carbonization chamber through bearings; a spiral conveying blade is arranged on the conveying shaft; One end of the conveying shaft extends out of the carbonization chamber and is connected to a driving motor, and the conveying shaft is sealed and connected to the carbonization chamber; The driving motor is fixedly arranged on the bracket.

9. A pyrolysis system for harmless treatment of chemical waste salt as claimed in claim 8, characterized in that: The spiral conveying blades of the material conveying device in the same carbonization chamber are arranged in a staggered manner.

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