A high-efficiency and energy-saving disposal system for waste salt

Abstract

The utility model belongs to the field of waste salt resource utilization, disclose a kind of waste salt efficient energy-saving disposal system, including waste salt pretreatment and conveying system, organic matter removal system, material collection and storage system and waste gas treatment system, use a kind of organic matter decomposition device, waste salt realizes the efficient decomposition including organic matter, phenol in fluidization state, solve the organic matter in waste salt exceed the standard, cannot be reused to chlor-alkali chemical ion membrane system, cause a large amount of waste salt to be piled up and cannot use technical problem, organic matter decomposition device in the system has no power equipment, material is in fluid state and carries out convection heat transfer, and heat efficiency is high, and energy-saving effect is obvious, simultaneously, the system uses desulfurization, dust removal device, prevent air pollution, with good economic benefit and environmental protection benefit, with popularization value.

Description

Technical Field

[0001] This utility model belongs to the field of waste salt resource utilization, and in particular relates to a high-efficiency and energy-saving waste salt disposal system. Background Technology

[0002] With the rapid development of my country's economy, the amount of waste salt generated by industries such as chlor-alkali chemical, coal chemical, organosilicon, lithium battery, textile, pharmaceutical, and fine chemical has been increasing year by year, with approximately 30 million tons of chemical waste salt generated annually. Its main components are sodium chloride, miscellaneous salts, and sodium sulfate. Although various industries have carried out evaporation crystallization and dehydration to collect sodium chloride and cooling crystallization to separate sodium sulfate from chemical waste salt, the chemical waste salt is complex due to the industry origin and mostly comes from production wastewater. The organic matter TOC, phenols, ammonia, and heavy metals in it exceed the standards, so it cannot be directly recycled for chemical production, let alone used to produce food products. Landfilling and discharge into the sea have limitations, and the hidden dangers of waste salt have not been eradicated. Moreover, industrial waste salt contains a large number of usable resources, so it is urgent to realize the resource-based treatment of industrial waste salt.

[0003] Because the chemical substances in waste salt are soluble salts, they can pollute the soil and groundwater. Therefore, they can only be disposed of by landfill, and only rigid landfill can be used. The disposal is carried out by professional companies. The disposal cost varies from 1,000 to 3,500 yuan per ton depending on the region. The disposal of large quantities of waste salt not only imposes a heavy economic burden on enterprises, but also pollutes the environment.

[0004] Currently, in order to promote the resource utilization of waste salt, some companies purify sodium chloride from waste salt for use in de-icing agents and sodium sulfate for manufacturing products such as sodium sulfate. However, the amount of chemical waste salt generated cannot meet the demand in these fields, resulting in a large amount of waste salt being piled up.

[0005] By utilizing sodium chloride from waste salt in conjunction with existing chlor-alkali chemical processes, the waste salt can be purified and directly fed into the ion-exchange membrane workshop as brine for the production of ion-exchange membrane caustic soda and PVC, thus achieving resource utilization. This not only simplifies the process and reduces treatment costs, becoming an effective means to promote the resource utilization of chemical waste salt, but also enables the effective use of large quantities of waste salt in chlor-alkali chemical processes. However, the organic matter in the waste salt has a significant impact on the service life of the ion-exchange membrane, and membrane replacement is a major cost item in the production and operation of chlor-alkali chemical processes. The chlor-alkali chemical industry requires that the TOC content in the brine be less than 10 mg / L before use, and reducing the organic matter content in the waste salt is a prerequisite for the use of chemical waste salt.

[0006] Chinese patent CN202321137562.1 discloses a novel waste salt treatment system. This technology discloses a pyrolysis kiln employing a rotary upper kiln and a rotary lower kiln, along with a waste gas treatment system. It achieves the pyrolysis treatment of volatile organic compounds in chemical waste salt. However, the rotary kiln's thermal efficiency is less than 40%, and its large equipment weight and low operating speed result in low production efficiency. Furthermore, its process system is complex, especially the waste gas treatment system, which has many components. A problem in any of these systems can affect the continuous operation of the treatment system, causing systemic shutdowns, high operating and maintenance costs, and high waste salt treatment costs, thus lacking economic advantages for widespread application. Chinese patent CN202210959784.5 discloses a device and process for deep removal of organic matter from waste salt through pyrolysis. This technology discloses a pyrolysis reactor, a deep purification chamber, a waste salt cooling drum, a discharge device, and a secondary combustion chamber. It achieves complete pyrolysis of waste salt in the reactor, improving the heat exchange rate. However, the waste gas after pyrolysis contains sulfur (S) and nitrogen (NO). X The lack of treatment of air pollutants and toxic and harmful components has caused secondary pollution to the environment. Summary of the Invention

[0007] The purpose of this invention is to provide a high-efficiency and energy-saving waste salt disposal system. This system effectively addresses the problem in existing technologies where waste salt, after dissolution, filtration, precipitation, and subsequent treatment including evaporation, crystallization, centrifugal dehydration, and heavy metal removal, transforms from hazardous waste into ordinary solid waste. However, the excessive organic matter and ammonia content prevent its direct application in chlor-alkali chemical processes for the resource utilization of sodium chloride. Secondly, this invention provides a high-efficiency and energy-saving waste salt disposal system that can efficiently pyrolyze the organic matter in waste salt. The process is simple, requires less power equipment, effectively reduces disposal costs, and makes the effective resource utilization of waste salt possible. Thirdly, this invention provides a high-efficiency and energy-saving waste salt disposal system that not only effectively collects dust generated during waste salt disposal, reducing material consumption and loss and preventing dust pollution, but also removes sulfur from the pyrolysis exhaust gas, preventing atmospheric pollution. In conclusion, this invention provides a high-efficiency and energy-saving waste salt disposal system that efficiently removes organic matter through pyrolysis, with a simple process, requiring less power equipment, low disposal costs, and minimal dust pollution, applicable to the resource utilization of sodium chloride in chlor-alkali chemical processes.

[0008] To achieve the above objectives, this utility model employs the following technical solution: A high-efficiency and energy-saving waste salt disposal system includes a waste salt pretreatment and conveying system, an organic matter removal system, a material collection and storage system, and a waste gas treatment system. The metering device in the waste salt pretreatment and conveying system is connected to the airlock feeding device a in the organic matter removal system; the hot air outlet of the organic matter decomposition device in the organic matter removal system is connected to the hot air inlet b of the cyclone dust collector in the material collection and storage system; and the hot air outlet b of the cyclone dust collector in the material collection and storage system is connected to the high-temperature fan in the waste gas treatment system.

[0009] The aforementioned high-efficiency and energy-saving waste salt disposal system comprises a waste salt pretreatment and conveying system consisting of a lifting device a, an intermediate silo, a crushing and grinding device, a lifting device b, a flow stabilizing silo, and a metering device connected in sequence. The waste salt is crushed and ground to achieve an appropriate fineness, thereby fully fluidizing the waste salt in the organic matter decomposition device, improving heat exchange efficiency and thermal decomposition efficiency. At the same time, an intermediate silo and a flow stabilizing silo are set in the system to achieve uniform and stable material supply.

[0010] The aforementioned high-efficiency and energy-saving waste salt disposal system includes an organic matter removal system comprising a lock-air feeding device a and an organic matter decomposition device connected in sequence. The lock-air feeding device a serves two purposes: firstly, it ensures that the material enters the organic matter decomposition device uniformly and stably, maintaining a stable fluidized field within the device; secondly, it prevents cold air from leaking into the device and reducing thermal efficiency. After entering the organic matter decomposition device, the waste salt is fully dispersed by the high-speed hot airflow, resulting in gas-solid mixing and fluidization. Convective heat transfer occurs as the airflow flows, and the organic matter is heated and decomposed into gaseous substances including water, carbon dioxide, and sulfur.

[0011] The aforementioned high-efficiency and energy-saving waste salt disposal system comprises a material collection and storage system consisting of a cyclone dust collector, a lock-air feeding device b, a high-temperature fan, and a finished product silo connected in sequence. The gas-solid mixture from the aforementioned organic matter decomposition device undergoes swirling motion in the cyclone dust collector. After gas-solid separation, the solid particles enter the finished product silo for storage and standby through the lock-air feeding device b. The waste gas is carried away by the high-temperature fan.

[0012] The aforementioned high-efficiency and energy-saving waste salt disposal system comprises a waste gas treatment system consisting of a high-temperature fan, a desulfurization tower, a lime storage silo, an electrostatic precipitator / bag filter, a system fan, a chimney, a conveying device, an lifting device, and a dust collection silo connected in sequence. After the waste gas passes through the desulfurization tower to remove sulfur, it enters the electrostatic precipitator / bag filter. The dust is collected and conveyed to the dust collection silo, thus achieving waste gas purification and reducing material consumption and waste.

[0013] The aforementioned high-efficiency and energy-saving waste salt disposal system includes an organic matter decomposition device in its organic matter removal system. This device comprises a hot air inlet a, a lower U-shaped pipe, a slag discharge port, a constriction port, a feed pipe, an upper U-shaped pipe, and a hot air outlet a, all connected sequentially. One end of the organic matter decomposition device, the hot air inlet a, is connected to a hot air stream, while the other end, the hot air outlet a, is connected to the hot air inlet b of a cyclone dust collector in the material collection and storage system. After the waste salt particles enter the organic matter decomposition device through the feed pipe, they are lifted by the hot air stream with increased wind speed at the constriction port, rapidly dispersed and fluidized, and undergo heat transfer. The hot air stream at a temperature of 500℃-800℃ rapidly heats the waste salt particles, and the organic matter, including substances such as phenols, is rapidly heated and decomposed quickly in the fluidized air stream. The decomposition process in the dispersed state is more thorough and faster, and the decomposed mixture is carried away by the air stream.

[0014] The aforementioned high-efficiency and energy-saving waste salt disposal system connects the hot flow inlet b of the cyclone dust collector to the hot flow outlet a of the organic matter decomposition device. The hot flow outlet b of the cyclone dust collector is connected to a high-temperature fan. The lower airlock feeding device b of the cyclone dust collector is connected to the finished product silo. The decomposed waste salt particles carried in the hot flow mixture undergo swirling motion in the cyclone dust collector. After gas-solid separation, the solid particles are discharged into the finished product silo for storage and later use through the airlock feeding device b.

[0015] The aforementioned high-efficiency and energy-saving waste salt disposal system has a desulfurization tower in its waste gas treatment system. The lower part of the desulfurization tower is connected to the outlet of a high-temperature fan, and the upper part is connected to one end of an electrostatic precipitator / bag filter. The middle and lower parts of the desulfurization tower are connected to a lime storage silo. The waste gas is sent into the desulfurization tower by the high-temperature fan, and the lime from the lime storage silo is sprayed into the bottom of the desulfurization tower to react with the sulfur in the rising airflow to generate desulfurized gypsum calcium sulfate, thereby removing the sulfur and preventing air pollution.

[0016] The beneficial effects of this utility model are as follows: It provides a high-efficiency and energy-saving waste salt disposal system. Waste salt lumps are crushed and ground to a suitable fineness, and then fully fluidized upon entering the organic matter decomposition device. This prevents large pieces of waste salt from being unable to be lifted by the airflow and falling to the bottom. Simultaneously, the fine particles of waste salt have a larger contact area with the hot airflow in the organic matter decomposition device, increasing the heat exchange rate. This allows for the full decomposition of organic matter and volatiles, improving both heat exchange efficiency and material decomposition efficiency. The waste salt particles are preheated in a fluidized state within the organic matter decomposition device, with the hot airflow making full contact with the particles. Heat exchange is achieved during the simultaneous flow of airflow and material particles, using convective heat exchange to decompose the organic matter in the waste salt, further increasing the heat exchange rate. Moreover, the fluidized heat exchange ensures uniform heating of the material, preventing carbon buildup in the finished product. The residues and incompletely reacted residues caused by uneven heating maintain stable quality. Furthermore, the organic matter decomposition device utilizes waste heat from exhaust gas as a heating source, reducing energy consumption from sources such as coal, electricity, and natural gas, resulting in significant energy savings. The fluidized bed heat exchange offers high heat exchange efficiency and utilization rate. The system incorporates intermediate and stabilizing chambers, ensuring more stable material supply and metering, guaranteeing stable system operation and product quality. The system includes dust removal and desulfurization devices, ensuring that exhaust gas emissions meet national air pollutant emission standards. With no waste liquid discharge, the system offers excellent economic and environmental benefits, significant energy savings, and stable product quality. Moreover, the system is reliable, performs well, and has significant potential for widespread adoption. Attached Figure Description

[0017] Appendix Figure 1 This is a schematic diagram of the process of this utility model; Appendix Figure 2 This is a schematic diagram of the organic matter decomposition device in this utility model; The components are as follows: 1. Lifting device a; 2. Intermediate silo; 3. Crushing and grinding device; 4. Lifting device b; 5. Flow stabilizing silo; 6. Metering device; 7. Airlock feeding device a; 8. Organic matter decomposition device; 9. Cyclone dust collector; 10. High-temperature fan; 11. Desulfurization tower; 12. Lime storage silo; 13. Electrostatic precipitator / bag filter composite dust collector; 14. System fan; 15. Chimney; 16. Conveying device; 17. Lifting device c; 18. Finished product silo; 19. Narrowing; 20. Airlock feeding device b; 21. Slag discharge port; 22. Lower U-shaped pipe; 23. Hot air inlet a; 24. Upper U-shaped pipe; 25. Hot air outlet a; 26. Feed pipe; 27. Hot air inlet b; 28. Hot air outlet b; 29. ​​Dust collection silo. Detailed Implementation

[0018] The following is in conjunction with the appendix Figure 1 With appendix Figure 2The specific embodiments given provide a more detailed description of this utility model, but do not constitute any limitation on the present invention. Example

[0019] Refer to the instruction manual appendix Figure 1 and 2 This embodiment provides a high-efficiency and energy-saving waste salt disposal system, including a waste salt pretreatment and conveying system, an organic matter removal system, a material collection and storage system, and a waste gas treatment system. The waste salt pretreatment and conveying system consists of a lifting device a1, an intermediate silo 2, a crushing and grinding device 3, a lifting device b4, a flow stabilizing silo 5, and a metering device 6 connected in sequence. The organic matter removal device consists of an airlock feeding device a7 and an organic matter decomposition device 8 connected in sequence. The material collection and storage system consists of a cyclone dust collector 9, an airlock feeding device b20, and a finished product silo 18 connected in sequence. The waste gas treatment system consists of a high-temperature fan 10, a desulfurization tower 11, a lime storage silo 12, an electrostatic precipitator / bag filter 13, a system fan 14, a chimney 15, a conveying device 16, a lifting device c17, and a dust collection silo 29 connected in sequence. The metering device 6 in the waste salt pretreatment and conveying system is connected to the airlock feeding device a7 in the organic matter removal system. The hot air outlet a25 of the organic matter decomposition device 8 in the organic matter removal system is connected to the hot air inlet b27 of the cyclone dust collector 9 in the material collection and storage system. The hot air outlet b28 of the cyclone dust collector 9 in the material collection and storage system is connected to the high-temperature fan 10 in the waste gas treatment system; the organic matter decomposition device in the organic matter removal system is equipped with a hot air inlet a23, a lower U-shaped pipe 22, a slag discharge port 21, a constriction 19, a feed pipe 26, an upper U-shaped pipe 24, and a hot air outlet 25a. These structures are connected sequentially. One end of the organic matter removal device, the hot air inlet a23, is connected to the hot air, and the other end, the hot air outlet a25a, is connected to the cyclone dust collector in the material collection and storage system. The hot air inlet b27 of the cyclone dust collector is connected to the hot air outlet a25 of the organic matter decomposition device; the hot air outlet b28 of the cyclone dust collector 9 is connected to the high temperature fan 10; the lower airlock feeding device b20 of the cyclone dust collector 9 is connected to the finished product silo 18; the lower part of the desulfurization tower 11 in the waste gas treatment system is connected to the outlet of the high temperature fan 10; the upper part of the desulfurization tower 11 is connected to one end of the electrostatic precipitator / bag filter composite dust collector 13; and the middle and lower part of the desulfurization tower 10 is connected to the lime storage silo 12.

[0020] The working process of this utility model is as follows: Solid waste salt from industries such as coal chemical, organosilicon, lithium battery, textile, pharmaceutical, petrochemical, high-salt wastewater, and fine chemical is transported to intermediate silo 2 for storage via lifting device a1. The solid waste salt then goes to crushing and grinding device 3, where large pieces of waste salt are crushed and ground to particles with a fineness of less than 3mm before entering lifting device b4. The waste salt is then lifted to stable flow silo 5 for standby. In continuous production, the material flows in and out in a continuous flow manner, and the appropriate system output is controlled by metering device 6. Then it enters the airlock feeding device a7, and through the feed pipe 26, it enters the lower constriction 19 of the organic matter decomposition device 8. The hot exhaust gas from the kiln, with a temperature of 500-800℃, passes through the hot gas inlet a23, and through the lower U-shaped pipe 22 of the organic matter decomposition device 8. After the wind speed and kinetic energy are increased at the constriction 19, the waste salt is lifted and fluidized. Convection heat transfer is achieved in the organic matter decomposition device 8, and the moisture begins to evaporate. As the temperature rises, the organic matter and volatiles decompose. The hot gas and the decomposed waste salt particles... The mixture passes through the upper U-shaped pipe 24 of the organic matter decomposition device, through the hot air outlet a25, and enters the hot air inlet b27 of the cyclone dust collector 9 through a pipeline. The fluidized mixture of waste salt decomposition particles and hot air undergoes material-gas separation in the cyclone dust collector. Simultaneously, the airflow and material are gradually cooled. The material passes through the air-shrinking discharge device b20 and enters the finished product silo 18 for storage. The exhaust gas exits the hot air outlet b28 of the cyclone dust collector 9 through a pipeline and is sent to the high-temperature fan 10. At the lower part of the desulfurization tower 11, as the exhaust gas enters the lower part of the desulfurization tower 11 and moves upward, lime from the lime storage bin 12 is sprayed in. The lime reacts with the sulfate ions in the exhaust gas to generate calcium sulfate. Then the exhaust gas mixture enters the electrostatic precipitator / bag filter 13. The electrostatic precipitator collects large dust particles in the electrostatic precipitator area and collects fine dust particles in the bag filter area. The mixture is then conveyed by the conveying device 16 to the lifting device c17 and lifted into the dust collection ash bin 29. The exhaust gas after dust collection passes through the system fan 14 and is discharged into the atmosphere through the chimney 15.

[0021] Solid waste salt undergoes fluidized convective heat exchange with kiln flue gas in the organic matter decomposition device 8, achieving organic matter decomposition during the process. This process is highly efficient and requires no power source. The waste salt and hot air are fluidized and moved by a high-temperature fan 10, making the process safe, simple, and easy to operate with significant energy savings. The system includes an intermediate chamber 2 and a flow stabilizing chamber 5, which facilitates material buffering and pressure control, ensuring continuous and stable feeding, consistent material quantity, and stable thermal operation. Sulfur is removed from the waste gas by injecting lime into the desulfurization tower 11, and dust particles in the waste gas are collected by an electrostatic precipitator / bag filter 13, reducing environmental pollution and demonstrating excellent performance.

Claims

1. A high-efficiency and energy-saving waste salt disposal system, characterized in that... The system includes a waste salt pretreatment and conveying system, an organic matter removal system, a material collection and storage system, and a waste gas treatment system connected in sequence. The metering device in the waste salt pretreatment and conveying system is connected to the airlock feeding device a in the organic matter removal system. The hot air outlet of the organic matter decomposition device in the organic matter removal system is connected to the hot air inlet b of the cyclone dust collector in the material collection and storage system. The hot air outlet b of the cyclone dust collector in the material collection and storage system is connected to the high-temperature fan in the waste gas treatment system.

2. The waste salt high-efficiency and energy-saving treatment system according to claim 1, characterized in that... The waste salt pretreatment and conveying system comprises a lifting device a, an intermediate silo, a crushing and grinding device, a lifting device b, a flow stabilizing silo, and a metering device connected in sequence.

3. The waste salt high-efficiency and energy-saving treatment system according to claim 1, characterized in that... The organic matter removal system comprises an airlock feeding device a and an organic matter decomposition device connected in sequence.

4. The waste salt high-efficiency and energy-saving disposal system according to claim 1, characterized in that... The material collection and storage system comprises a cyclone dust collector, an airlock feeding device (b), and a finished product silo connected in sequence.

5. The waste salt high-efficiency and energy-saving treatment system according to claim 1, characterized in that... The exhaust gas treatment system comprises a high-temperature fan, a desulfurization tower, a lime storage silo, an electrostatic precipitator / bag filter, a system fan, a chimney, a conveying device, an lifting device, and a dust collection silo connected in sequence.

6. A high-efficiency and energy-saving waste salt disposal system according to claim 1 or 3, characterized in that... The organic matter decomposition device in the organic matter removal system is equipped with a hot air inlet a, a lower U-shaped pipe, a slag discharge port, a constriction port, a feed pipe, an upper U-shaped pipe, and a hot air outlet a, which are connected sequentially. One end of the organic matter decomposition device, the hot air inlet a, is connected to the hot air flow, and the other end, the hot air outlet a, is connected to the hot air inlet b of the cyclone dust collector in the material collection and storage system.

7. A high-efficiency and energy-saving waste salt disposal system according to claim 1 or 4, characterized in that... The hot air inlet b of the cyclone dust collector is connected to the hot air outlet a of the organic matter decomposition device, the hot air outlet b of the cyclone dust collector is connected to the high-temperature fan, and the lower airlock feeding device b of the cyclone dust collector is connected to the finished product silo.

8. A high-efficiency and energy-saving waste salt disposal system according to claim 1 or 5, characterized in that... The lower part of the desulfurization tower in the exhaust gas treatment system is connected to the outlet of the high-temperature fan, the upper part is connected to one end of the electrostatic precipitator and bag filter, and the middle and lower part of the desulfurization tower is connected to the lime storage silo.

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