System and method for removing organic matters from industrial waste salt at high temperature

Abstract

The invention discloses a system and a method for removing organic matters from industrial waste salt at high temperature, and relates to the technical field of industrial salt recycling, the system for removing organic matters from industrial waste salt at high temperature comprises: a pretreatment system for pretreating industrial waste salt to form a gas-solid mixture; the pyrolysis system communicates with the pretreatment system and is used for receiving the gas-solid mixture, and the pyrolysis system is used for pyrolyzing the gas-solid mixture; the energy recovery system is communicated with the pyrolysis system, and the energy recovery system is used for recovering heat generated after the gas-solid mixture is pyrolyzed; the gas-solid separation system is communicated with the pyrolysis system, and the gas-solid separation system is used for decomposing the gas-solid mixture into gas and solid; and the salt dissolving system is communicated with the gas-solid separation system and is used for carrying out salt dissolving on the decomposed solid. According to the system and the method for removing the organic matters from the industrial waste salt at the high temperature, the industrial waste salt can be subjected to harmless and resourceful treatment, so that the utilization rate of the industrial waste salt is increased.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of industrial salt resource, more particularly, to an industrial waste salt high-temperature organic matter removal system. BACKGROUND

[0002] Industrial waste salt mainly comes from chemical industry, pharmaceutical industry, pesticide industry, coal chemical industry and other industries. The chemical materials of these enterprises are treated under acid and alkali conditions through chemical reaction, salting-out, color fixing and other processes, producing high-salt wastewater. The wastewater is treated by biochemical, evaporation, crystallization and other processes, and finally a mixture of one or more inorganic salts such as NaCl, Na2SO4 and Na2SO3 and organic pollutants, i.e. industrial waste salt, is produced, which belongs to hazardous waste.

[0003] Industrial waste salt has certain toxicity. Since it is non-degradable and non-combustible, there is no effective and "secondary pollution" disposal method in the industry. The main reason is that the removal rate of organic matter in solid materials in the existing technology cannot meet the use requirements of downstream enterprises. With the further increase of the proportion of industrial waste salt in caustic soda industry, the development of technology is required. The important factor restricting the development of industrial waste salt is that the content of organic matter is difficult to handle, and it is difficult to meet the use requirements of downstream application industries. For example, the caustic soda industry requires TOC<10ppm to meet the requirements of the downstream caustic soda industry. Otherwise, it is difficult to realize large-scale application and further resource recycling.

[0004] The boiling point of organic matter in waste salt is relatively high, reaching 200-600℃. The traditional wet oxidation technology has low efficiency and is only limited to low-concentration organic matter. It is difficult to meet the standard treatment of waste salt with high-concentration organic matter. For industrial waste salt with high organic matter content, the current main methods are high-temperature incineration and high-temperature melting, which have significant effect on removing organic matter. However, they have application limitations. For example, high-temperature incineration and melting need to be heated to 800-1200℃, which has high energy consumption, large amount of flue gas, and high energy consumption of melting method compared with incineration method by 30%-50%. The operation cost is high, the equipment investment is high, and it is difficult to promote on a large scale.

[0005] In summary, how to harmlessly and resourcefully treat waste salt to improve its utilization rate is a problem to be solved by the technical personnel in the field. SUMMARY

[0006] Therefore, the purpose of the present application is to provide an industrial waste salt high-temperature organic matter removal system, which can pretreat industrial waste salt, pyrolyze industrial waste salt, recycle pyrolysis energy, and finally separate gas and solid and salt, so as to harmlessly and resourcefully treat waste salt to improve its utilization rate.

[0007] Another object of the present application is to provide a method suitable for the above-mentioned system for removing organic matters from industrial waste salt at high temperature.

[0008] To achieve the above object, the present application provides the following technical solutions.

[0009] A system for removing organic matters from industrial waste salt at high temperature comprises:

[0010] A pretreatment system for pretreating the industrial waste salt to form a gas-solid mixture;

[0011] A pyrolysis system in communication with the pretreatment system and configured to receive the gas-solid mixture, the pyrolysis system being configured to pyrolyze the gas-solid mixture;

[0012] An energy recovery system in communication with the pyrolysis system, the energy recovery system being configured to recover heat generated after pyrolysis of the gas-solid mixture;

[0013] A gas-solid separation system in communication with the pyrolysis system, the gas-solid separation system being configured to separate the gas-solid mixture into gas and solid;

[0014] A salt dissolving system in communication with the gas-solid separation system, the salt dissolving system being configured to dissolve the separated solid.

[0015] Preferably, the pretreatment system comprises, in sequence, a scatterer, a gas-locking discharge valve, a feeder, a rotary dryer, a grinder and a cyclone dust collector, the scatterer being configured to preheat and scatter the industrial waste salt, the gas-locking discharge valve being configured to prevent backflow of gas in the feeder to the scatterer, the feeder being provided with an air inlet, the rotary dryer being configured to dry the gas-solid mixture inside, the grinder being configured to grind the gas-solid mixture, and the cyclone dust collector being configured to absorb exhaust gas in the grinder.

[0016] Preferably, the scatterer is provided with a scatterer inlet, a scatterer outlet, a circulating water heating jacket and an exhaust gas discharge port, the circulating water heating jacket being provided with a jacket water inlet and a jacket water outlet, the jacket water inlet being configured to introduce hot circulating water into the circulating water heating jacket, and the jacket water outlet being configured to discharge the cooled hot circulating water, the gas-locking discharge valve being provided with a valve inlet in communication with the scatterer outlet, and a valve outlet in communication with a feeder inlet of the feeder, and the feeder being further provided with a feeder air inlet in communication with the exhaust gas discharge port.

[0017] Preferably, the rotary dryer comprises a salt dust outlet and a dryer discharge outlet, the cyclone comprises a cyclone inlet, a cyclone outlet and a double hammer flap valve, the mill comprises a coarse salt inlet, a salt powder inlet, a mill air inlet, a gas-solid mixture air outlet, a circulating water inlet and a circulating water outlet, a mill roller and a dynamic separator;

[0018] The salt dust outlet is in communication with the cyclone inlet, the dryer discharge outlet is in communication with the coarse salt inlet, the salt powder inlet is connected with the double hammer flap valve, the circulating water inlet is in communication with a water supply assembly, the circulating water outlet is in communication with the jacket water inlet, and the mill roller and the dynamic separator are both arranged in the interior of the mill.

[0019] Preferably, the pyrolysis system comprises a hot blast furnace, a Venturi mixer, a pyrolysis furnace and a microwave heater, the hot blast furnace, the Venturi mixer and the pyrolysis furnace are sequentially in communication, two ends of the microwave heater are respectively in communication with the Venturi mixer and the pyrolysis furnace, the hot blast furnace is used for producing hot blast and feeding the hot blast into the Venturi mixer, the Venturi mixer is in communication with the mill and is used for receiving the gas-solid mixture in the mill and the hot blast from the hot blast furnace, so that the gas-solid mixture is pyrolyzed in the pyrolysis furnace, and the microwave heater is used for heating the return material of the pyrolysis furnace to the Venturi mixer.

[0020] Preferably, the hot blast furnace comprises a combined burner and a high-temperature flue gas outlet, the Venturi mixer comprises a high-temperature flue gas inlet, a mixer air inlet, a mixer inlet and a mixer outlet, the pyrolysis furnace comprises a pyrolysis furnace inlet, a pyrolysis furnace mixing outlet and a pyrolysis furnace return material outlet, the combined burner is used for producing hot blast, the high-temperature flue gas outlet is in communication with the high-temperature flue gas inlet, the mixer air inlet is in communication with the gas-solid mixture air outlet, the mixer inlet is in communication with the first end of the microwave heater, the mixer outlet is in communication with the pyrolysis furnace inlet, and the pyrolysis furnace return material outlet is in communication with the second end of the microwave heater.

[0021] Preferably, the energy recovery system comprises an air preheater, the air preheater comprises an air preheater air inlet, an air preheater air outlet, a cold air inlet and a hot air outlet, the air preheater air inlet is in communication with the pyrolysis furnace mixing outlet, the cold air inlet is in communication with the air outlet of a blower, and the hot air outlet is in communication with the hot blast furnace.

[0022] Preferably, the gas-solid separation system comprises a cyclone separator and a dust collector, the cyclone separator comprises a separator air inlet, a separator air outlet and a heavy hammer flap valve discharge port, the dust collector comprises a dust collector air inlet, a dust collector air outlet and a bottom flap valve discharge port, the separator air inlet is communicated with the air preheater air outlet, the separator air outlet is communicated with the dust collector air inlet, and the dust collector air outlet is communicated with the combined burner.

[0023] Preferably, the salt dissolving system comprises a salt dissolving tank, the salt dissolving tank is provided with a first inlet and a second inlet, the first inlet is communicated with the heavy hammer flap valve discharge port, and the second inlet is communicated with the bottom flap valve discharge port, and the salt dissolving tank is further provided with a water inlet, a water outlet, an overflow weir and a stirrer.

[0024] A method for removing organic matter from industrial waste salt at high temperature, applicable to an industrial waste salt high-temperature organic matter removal system.

[0025] The industrial waste salt high-temperature organic matter removal system provided by the application can pretreat industrial waste salt, mix the industrial waste salt with gas to form a gas-solid mixture, pyrolyze the gas-solid mixture by a pyrolysis system, recover heat generated in the pyrolysis process by an energy recovery system, separate the gas-solid mixture into gas and solid by a gas-solid separation system, and dissolve the solid by a salt dissolving system, so as to realize harmless and resourceful treatment of the waste salt and improve the utilization rate of the waste salt. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of the provided drawings.

[0027] Figure 1 The structure diagram of the industrial waste salt high-temperature organic matter removal system provided by the present application;

[0028] Figure 2 The flow chart of the industrial waste salt high-temperature organic matter removal system provided by the present application.

[0029] Reference signs:

[0030] 1-disintegrator; 101-disintegrator inlet; 102-disintegrator outlet; 103-jacket water inlet; 104-jacket water outlet; 105-waste gas discharge port; 2-gas-locking blanking valve; 201-blanking valve inlet; 202-blanking valve outlet; 3-feeder; 301-feeder inlet; 302-air inlet; 303-feeder air inlet; 4-rotary dryer; 401-salt dust containing outlet; 402-dryer outlet; 5-cyclone dust collector; 501-dust collector inlet; 502-dust collector outlet; 503-heavy hammer flap valve; 6-mill; 601-coarse salt inlet; 602-salt powder inlet; 603-mill air inlet; 604-gas-solid mixture air outlet; 605-circulating water inlet; 606-circulating water outlet; 607-mill roller; 608-dynamic separator; 7-hot blast stove; 701-combined burner; 702-high-temperature flue gas outlet; 8-venturi mixer; 801-high-temperature flue gas inlet; 802-mixer air inlet; 803-mixer inlet; 804-mixer outlet; 9-pyrolysis furnace; 901-pyrolysis furnace inlet; 902-pyrolysis furnace mixing outlet; 903-pyrolysis furnace return inlet; 10-microwave heater; 11-air preheater; 1101-air preheater air inlet; 1102-air preheater air outlet; 1103-cold air inlet; 1104-hot air outlet; 12-cyclone separator; 1201-separator air inlet; 1202-separator air outlet; 1203-heavy hammer flap valve outlet; 13-dust collector; 1301-dust collector air inlet; 1302-dust collector air outlet; 1303-bottom flap valve outlet; 14-salt dissolving tank; 1401-first inlet; 1402-second inlet; 1403-water inlet; 1404-drainage outlet; 1405-overflow weir; 1406-agitator; 15-blower. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0032] The core of the present application is to provide an industrial waste salt high-temperature organic matter removal system, which can harmlessly and resourcefully treat waste salt and improve the utilization rate of industrial waste salt.

[0033] Another core of the present application is to provide a method suitable for the above-mentioned industrial waste salt high-temperature organic matter removal system.

[0034] It should be noted that the directions or positional relationships indicated by "upper", "lower", "front", "back" and the like are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0035] The present application provides an industrial waste salt high-temperature organic matter removal system, comprising: a pretreatment system, a pyrolysis system, an energy recovery system, a gas-solid separation system and a salt conversion system;

[0036] The pretreatment system is used for pretreating the industrial waste salt to form a gas-solid mixture;

[0037] The pyrolysis system is in communication with the pretreatment system and is used for receiving the gas-solid mixture, and the pyrolysis system is used for pyrolyzing the gas-solid mixture;

[0038] The energy recovery system is in communication with the pyrolysis system, and the energy recovery system is used for recovering heat generated after pyrolysis of the gas-solid mixture;

[0039] The gas-solid separation system is in communication with the pyrolysis system, and the gas-solid separation system is used for decomposing the gas-solid mixture into gas and solid;

[0040] The salt conversion system is in communication with the gas-solid separation system, and the salt conversion system is used for converting the decomposed solid into salt.

[0041] Specifically, the industrial waste salt enters the pretreatment system, the pretreatment system can pretreat the industrial waste salt, the industrial waste salt is scattered, preheated, dried and ground in the pretreatment system, and the ground industrial waste salt flows with the blast air, or in other words, the industrial waste salt moves in the entire system in the form of a gas-solid mixture. After the gas-solid mixture enters the pyrolysis system, the pyrolysis system can pyrolyze the gas-solid mixture, and the energy generated during the pyrolysis process is recovered by the energy recovery system. Thereafter, the gas-solid mixture enters the gas-solid separation system and is separated into solid and gas by the gas-solid separation system. The salt conversion system is used for receiving the solid, and after purification and impurity removal, the TOC is less than 10 ppm, which can be used in the chlor-alkali industry. The separated pyrolysis residual carbon can also be resourceized. From the above content, the harmless, reduction and resourceful treatment of the industrial waste salt can be realized, the system has high integration, can be applied on a large scale in industry, has high thermal efficiency, small environmental pollution, wide applicability, and broad market development prospects.

[0042] Based on the above embodiment, the pretreatment system includes a disperser 1, an air-locking discharge valve 2, a feeder 3, a rotary dryer 4, a grinder 6 and a cyclone dust collector 5 connected in sequence. The disperser 1 is used to preheat and disperse industrial waste salt. The air-locking discharge valve 2 is used to prevent the gas in the feeder 3 from flowing back to the disperser 1. The feeder 3 is provided with an air inlet 302. The rotary dryer 4 is used to dry the gas-solid mixture inside it. The grinder 6 is used to grind the gas-solid mixture. The cyclone dust collector 5 is used to absorb the exhaust gas in the grinder 6.

[0043] Specifically, the structure of the pretreatment system can be found in the attached Figure 1 The pulverizer 1, the air-locking discharge valve 2, the feeder 3, the rotary dryer 4, the grinder 6 and the cyclone dust collector 5 are connected in sequence. The industrial waste salt enters the pretreatment system from the pulverizer 1 for preheating and pulverization. If the industrial salt is stored for a long time, it may be agglomerated or compacted. If compaction occurs, a roller press can be set for pretreatment to avoid problems such as bridging of large pieces affecting the normal operation of the pulverizer 1. The air-locking discharge valve 2 can prevent the gas in the conveying pipeline from flowing back into the pulverizer 1, and can also adjust the discharge speed and content as needed to achieve continuous and uniform falling of the material. The feeder 3 is provided with an air inlet 302 to achieve mixing of industrial waste salt and gas. The rotary dryer 4 can dry the gas-solid mixture. After receiving the gas-solid mixture, the industrial waste salt accumulates inside the grinder 6 and grinds the accumulated industrial waste salt. The cyclone dust collector can suck away the gas to complete the pretreatment.

[0044] On the basis of the above embodiments, the disperser 1 is provided with a disperser feed port 101, a disperser discharge port 102, a circulating water heating jacket and an exhaust gas discharge port 105. The circulating water heating jacket is provided with a jacket water inlet 103 and a jacket water outlet 104. The jacket water inlet 103 is used to introduce hot circulating water into the circulating water heating jacket, and the jacket water outlet 104 is used to discharge the cooled hot circulating water. The valve inlet 201 of the air lock discharge valve 2 is connected to the disperser discharge port 102, and the valve outlet 202 of the air lock discharge valve 2 is connected to the feeder feed port 301 of the feeder 3. The feeder 3 is also provided with a feeder air inlet 303 connected to the exhaust gas discharge port 105.

[0045] Specifically, the disperser feed port 101 is connected to the industrial waste salt feeding assembly B, the disperser 1 is provided with a circulating water heating jacket, the jacket water inlet 103 is connected to the circulating water return outlet 606, the jacket water outlet 104 goes to the external pipe and is connected to the circulating water return port A, the water inlet temperature range is 65 ~ 90 ℃, the water outlet temperature is 42 ℃, the disperser 1 is provided with an exhaust gas discharge port 105 connected to the feeder air inlet 303, the exhaust gas temperature range is 60 ~ 85 ℃, the loose salt and hot air in the feeder 3 are mixed and extended into the rotary dryer 4, and the air inlet temperature range is 300 ~ 400 ℃.

[0046] On the basis of the above embodiment, the rotary dryer 4 comprises a salt dust outlet 401 and a dryer discharge port 402, the cyclone dust collector 5 comprises a dust collector inlet 501, a dust collector outlet 502 and a double hammer flap valve 503, and the mill 6 comprises a coarse salt inlet 601, a salt powder inlet 602, a mill air inlet 603, a gas-solid mixture air outlet 604, a circulating water inlet 605, a circulating water outlet 606, a grinding roller 607 and a dynamic separator 608.

[0047] The salt dust outlet 401 is communicated with the dust collector inlet 501, the dryer discharge port 402 is communicated with the coarse salt inlet 601, the salt powder inlet 602 is connected with the double hammer flap valve 503, the circulating water inlet 605 is communicated with the water supply assembly, the circulating water outlet 606 is communicated with the jacket water inlet 103, and the grinding roller 607 and the dynamic separator 608 are arranged in the interior of the mill 6.

[0048] Specifically, the dryer discharge port 402 is connected with the coarse salt inlet 601, and the salt dust outlet 401 is connected with the dust collector inlet 501; the waste salt temperature range of the mill discharge port is 100-120℃, the top of the cyclone dust collector 5 is the dust collector outlet 502, the bottom is provided with the double hammer flap valve 503 connected with the salt powder inlet 602, the waste salt temperature range of the discharge port is 100-120℃, the mill air inlet 603 is connected with another branch pipe of the dust collector 13 air outlet, the gas-solid mixture air outlet 604 is connected with the mixer air inlet 802, the circulating water inlet 605 is from the external pipe network D, the circulating water outlet 606 is connected with the jacket water inlet 103, the grinding roller 607 is arranged on the internal grinding disc, and the dynamic separator 608 is arranged on the upper portion; the temperature range of the mill air inlet is 300-400℃, and the temperature of the air outlet is 200-250℃; it needs to be noted that the mill 6 is cooled by the circulating water system, and hot water is discharged for preheating the industrial waste salt in the dispersing machine, so that the waste heat of the system is fully recycled, and energy is saved.

[0049] Optionally, the dispersing machine 1 adopts a shaftless double helix structure, has the functions of mixing and dispersing, and has a heating jacket, so that the material can be preheated, the jacket water inlet temperature is 65-95℃, the jacket water outlet temperature is 42℃, the circulating water is returned to the recycling system, and the industrial waste salt is preheated to 60-90℃.

[0050] Optionally, the rotary dryer 4 adopts a spiral sawtooth lifting plate, which can increase the contact frequency and area of the material and hot flue gas, improve the drying efficiency, and the material temperature range is 100-120℃.

[0051] Optionally, the grinding roller 607 in the mill 6 adopts a mixed compression scheme of mechanical spring pre-tightening, flywheel energy storage and vibration assistance, which can significantly reduce the energy consumption of the hydraulic system of the medium-speed coal mill, and improve the grinding efficiency and the service life of the equipment.

[0052] On the basis of the above-mentioned embodiments, the pyrolysis system comprises a hot blast stove 7, a Venturi mixer 8, a pyrolysis stove 9 and a microwave heater 10, the hot blast stove 7, the Venturi mixer 8 and the pyrolysis stove 9 are sequentially communicated, two ends of the microwave heater 10 are communicated with the Venturi mixer 8 and the pyrolysis stove 9 respectively, the hot blast stove 7 is used for producing hot blast and introducing the hot blast into the Venturi mixer 8, the Venturi mixer 8 is communicated with the mill 6 and is used for receiving the gas-solid mixture in the mill 6 and the hot blast of the hot blast stove 7, so that the gas-solid mixture is pyrolyzed in the pyrolysis stove 9, and the microwave heater 10 is used for heating the return material of the pyrolysis stove 9 to the Venturi mixer 8.

[0053] Specifically, the combined burner 701 in the hot blast stove 7 is supplied with natural gas by the natural gas supply assembly E, system preheated air and waste salt pyrolysis flue gas, which can not only improve the energy use efficiency of the system, reduce energy consumption, but also reduce the amount of nitrogen oxide pollutants, the feed of the hot blast stove 7 adopts the Venturi mixer 8, which mixes the circulating flue gas, the mill discharge gas-solid mixture and the high-temperature return material of the pyrolysis stove, has the advantages of high mixing efficiency and small equipment investment, the oxygen content of the industrial waste salt high-temperature organic matter removal system is controlled to be less than 8%, which ensures the low-oxygen environment of the pyrolysis system, and when the oxygen concentration exceeds 5%, nitrogen gas is immediately supplemented for protection.

[0054] On the basis of the above-mentioned embodiments, the hot blast stove 7 comprises a combined burner 701 and a high-temperature flue gas outlet 702, the Venturi mixer 8 comprises a high-temperature flue gas inlet 801, a mixer air inlet 802, a mixer feed inlet 803 and a mixer discharge outlet 804, the pyrolysis stove 9 comprises a pyrolysis stove feed inlet 901, a pyrolysis stove mixing outlet 902 and a pyrolysis stove return material outlet 903, the combined burner 701 is used for producing hot blast, the high-temperature flue gas outlet 702 is communicated with the high-temperature flue gas inlet 801, the mixer air inlet 802 is communicated with the gas-solid mixture air outlet 604, the mixer feed inlet 803 is communicated with the first end of the microwave heater 10, the mixer discharge outlet 804 is communicated with the pyrolysis stove feed inlet 901, and the pyrolysis stove return material outlet 903 is communicated with the second end of the microwave heater 10.

[0055] Specifically, the hot blast furnace 7 provides heat energy by combusting natural gas through the combined burner 701, the high-temperature flue gas outlet 702 is connected with the high-temperature flue gas inlet 801, the hot blast furnace 7 adopts a natural gas direct combustion type, the temperature range of the high-temperature flue gas outlet 702 is 650-770℃, the mixer discharge port 804 is connected with the pyrolysis furnace feed inlet 901, the temperature range of the pyrolysis furnace feed inlet 901 is 500-600℃, the pyrolysis furnace mixing outlet 902 is connected with the air preheater air inlet 1101, the waste salt in the pyrolysis furnace 9 is in a fluidized state, and the materials with a larger particle size are repeatedly circulated, so that the pyrolysis efficiency is high and the energy consumption is low. The low-oxygen cracking process is used for the industrial waste salt, and the organic matters in the waste salt are decomposed into combustible gas, oxidizing and acidic gas, and a small amount of carbon powder. Part of the combustible gas is recycled into the hot blast furnace 7 through the flue gas, which can greatly reduce the generation amount of nitrogen oxides of the hot blast furnace. The remaining gas is used for air selection of a mill and drying of the waste salt. The drying tail gas contains a large amount of moisture, and is sent to a burning system for complete and safe treatment. The low-oxygen cracking technology is carried out in a reducing atmosphere in the whole reaction process, so that the generation conditions of pollutants are reduced from the source. The biggest advantage of the method is that toxic and harmful substances are basically not generated. However, the relative investment is relatively large. The microwave heater 10 is arranged outside the return pipe of the pyrolysis furnace 9, can heat the materials in the pyrolysis furnace 9 through microwaves, can accurately control the pyrolysis temperature, avoids that the pyrolysis temperature is too high and the waste salt is melted and adheres to the wall, and has important significance for improving the pyrolysis efficiency and maintaining the long-term stable operation of the system. The waste salt is mainly non-polar, and the microwaves selectively act on polar molecules (such as impurities and organic matters). The thermal efficiency is more than 85%, no medium is needed for conduction, and the energy consumption is only 40% of that of the traditional pyrolysis.

[0056] On the basis of the above embodiment, the energy recovery system comprises an air preheater 11, the air preheater 11 comprises an air preheater air inlet 1101, an air preheater air outlet 1102, a cold air inlet 1103 and a hot air outlet 1104, the air preheater air inlet 1101 is communicated with the pyrolysis furnace mixing outlet 902, the cold air inlet 1103 is communicated with the air outlet of the air blower 15, and the hot air outlet 1104 is communicated with the hot blast furnace 7.

[0057] Specifically, the air preheater air outlet 1102 is connected with the separator air inlet 1201, the cold air inlet 1103 is connected with the air outlet of the air blower 15, and the hot air outlet 1104 is connected with the hot blast furnace 7 through the air pipe and the burner. The air preheater 11 can preheat the ambient temperature air to 300-400℃, and the flue gas temperature is reduced to 300-400℃.

[0058] Optionally, the air preheater 11 adopts a material accumulation prevention sodium-potassium alloy heat pipe, has high heat conduction efficiency and fast heat transfer rate. The air preheater 11 preheats the combustion-supporting air entering the hot blast furnace burner, and simultaneously reduces the flue gas temperature, which has important significance for energy saving and consumption reduction.

[0059] On the basis of the above-mentioned embodiments, the gas-solid separation system comprises a cyclone separator 12 and a dust collector 13, the cyclone separator 12 comprises a separator air inlet 1201, a separator air outlet 1202 and a heavy hammer flap valve discharge port 1203, the dust collector 13 comprises a dust collector air inlet 1301, a dust collector air outlet 1302 and a bottom flap valve discharge port 1303, the separator air inlet 1201 is communicated with the air preheater air outlet 1102, the separator air outlet 1202 is communicated with the dust collector air inlet 1301, and the dust collector air outlet 1302 is communicated with the combined burner 701.

[0060] Specifically, the separator air outlet 1202 is connected with the dust collector air inlet 1301, the bottom is provided with the heavy hammer flap valve discharge port 1203 connected with the first feeding port 1401, and after the bottom salt accumulates a certain amount, the flap is automatically opened, the coarse salt at the bottom of the cyclone separator 12 enters the salt dissolving tank 14, the dust collector air outlet 1302 is divided into two paths and is respectively connected with the mill air inlet 603 and the air inlet of the combined burner 701 through pipelines, and the bottom flap valve discharge port 1303 is connected with the second feeding port 1402, and after the bottom salt accumulates a certain amount, the flap is automatically opened, and the fine salt at the bottom of the dust collector 13 enters the salt dissolving tank 14.

[0061] Optionally, the dust collector 13 adopts a high-temperature ceramic fiber filter cartridge, has high dust removal efficiency, and the stability is good at high temperature

[0062] On the basis of the above-mentioned embodiments, the salt dissolving system comprises a salt dissolving tank 14, the salt dissolving tank 14 is provided with a first feeding port 1401 and a second feeding port 1402, the first feeding port 1401 is communicated with the heavy hammer flap valve discharge port 1203, and the second feeding port 1402 is communicated with the bottom flap valve discharge port 1303, and the salt dissolving tank 14 is further provided with a water inlet 1403, a water outlet 1404, an overflow weir 1405 and a stirrer 1406.

[0063] Specifically, the water inlet 1403 is connected with the outer pipe F, the concentrated brine is discharged through the water outlet 1404 to the downstream process G for treatment, the salt dissolving tank is provided with the overflow weir 1405, the salt dissolving tank 14 is provided with the stirrer 1406, the stirrer 1406 can accelerate dissolution, an internal flow guide cylinder is arranged, and the internal flow guide cylinder is helpful for reasonable distribution of a fluid flow field, the residual carbon-containing salt solution is discharged through the overflow to the downstream for treatment, and through processes such as filtration, impurity removal and purification, the TOC can be less than 10 mg / L, so as to be applicable to the chlor-alkali industry.

[0064] Optionally, the salt dissolving tank 14 is provided with a densimeter, and the water quantity and the downstream solution concentration are controlled through the density.

[0065] In addition to the above-mentioned industrial waste salt high-temperature organic matter removal system, the application also provides a method suitable for the industrial waste salt high-temperature organic matter removal system disclosed in the above-mentioned embodiments, and the method comprises the following steps.

[0066] Step S1, preheat hot blast stove 7 and pyrolysis furnace 9;

[0067] Step S2, introduce production water into salt dissolving tank 14, and introduce circulating water into circulating water inlet 605;

[0068] Step S3, start air blower 15, and ignite hot blast stove 7;

[0069] Step S4, start stirrer 1406, microwave heater 10, mill 6, rotary dryer 4, air lock valve 2 and scatterer 1 in sequence at intervals of 30S;

[0070] Step S5, introduce industrial waste salt into scatterer 1;

[0071] Step S6, when cyclone separator 12 accumulates enough pyrolysis salt, the pyrolysis salt is introduced into salt dissolving tank 14 from heavy hammer flap valve discharge port 1203;

[0072] Step S7, continuously add production water into salt dissolving tank 14, when reaching the overflow liquid level, monitor the density of salt solution, when reaching the requirement, determine the amount of production water according to the overflow amount, to ensure the water balance and the concentration requirement of salt solution;

[0073] Step S8, recycle the salt solution to remove impurities and separate salt.

[0074] Specifically, after step S4, with the stable operation of the system, the temperature of each part reaches the set requirement, the flue gas temperature at high-temperature flue gas outlet 702 reaches 750℃, the temperature in pyrolysis furnace 9 ranges from 500 to 600℃, the temperature at air preheater inlet 1101 is normal temperature, the temperature at air preheater outlet ranges from 300 to 400℃, the flue gas temperature at dust collector outlet ranges from 300 to 400℃, which is divided into three paths, one path is the circulating flue gas of hot blast stove 7, accounting for 10% to 30% of the flue gas production of hot blast stove, another path is the mill inlet air, and the last path is the rotary kiln drying air, which is sent into rotary dryer 4 through feeder; the discharge air temperature of hot blast stove 7 ranges from 200 to 250℃, the outlet temperature of cyclone dust collector 5 ranges from 100 to 150℃, which is dry tail gas with high moisture content, and is sent to the incineration system for safe treatment; the temperature of pyrolysis furnace return material is raised to 650 to 770℃ after being heated by microwave heater, and the mixed salt does not exceed its melting temperature.

[0075] When the bottom hopper of the cyclone separator 12 accumulates enough pyrolysis salt, the heavy hammer flap valve discharge port 1203 is automatically opened, and the pyrolysis salt is discharged into the salt dissolving tank 14; then, production water is continuously added, and when the overflow liquid level is reached, the salt solution density is monitored, and when the downstream requirements are met, the production water quantity is determined according to the overflow quantity, so as to ensure the water quantity balance and the salt solution concentration requirements. The salt solution is sent to the downstream purification treatment, and through impurity removal, salt separation and other measures, it can be used for the production of caustic soda industry, or further processed to produce industrial products, so as to realize high-value utilization. The waste salt particle size of the mill air outlet is 0-50 microns, the particle size of the salt dissolving tank is 2-50 microns, and the recovery rate is more than 99.95%.

[0076] After the system is stably operated, the circulating water is used to cool and recover heat for the mill 6, the outlet water temperature is in the range of 60-95 DEG C, and is used to preheat the waste salt in the dispersing machine 1, the circulating water temperature is 42 DEG C, and the waste salt is preheated to 60-90 DEG C; the air preheater 11 is used to preheat the air of the hot blast furnace 7 by using the flue gas needing to be cooled, so as to realize heat energy recycling; the flue gas after being cooled by the air preheater 11 is used for flue gas recirculation, waste salt preheating, drying and temperature rising, so that the heat energy is recycled and reused in many aspects; the circulating flue gas contains organic pyrolysis combustible gas, and is sent into the hot blast furnace 7, so that the heat efficiency of the hot blast furnace 7 is improved, the energy consumption is reduced, and the content of nitrogen oxides is reduced, so that the system is environmentally friendly and efficient; the whole system comprehensively considers heat recovery and full utilization, so that the heat energy utilization rate of the system is improved, and the energy consumption of the system is reduced.

[0077] The application couples the large-scale application of high-temperature pyrolysis carbonization and the selectivity, rapidness and high efficiency of microwave pyrolysis, realizes accurate destruction of organic molecule chains at 400-770 DEG C, the organic removal rate is more than 99%, the TOC is less than 10 ppm, the purity of the treated salt reaches the industrial grade standard, and the salt can be directly reused in electrolysis, printing and dyeing and other production links. In addition, the application can optimize the pyrolysis temperature according to the composition of the organic matter contained in the specific waste salt, and the operation feasibility and adaptability are high. In the traditional pyrolysis process, whether it is high-temperature waste salt pyrolysis, high-temperature melting or microwave pyrolysis, it usually takes 1-2 hours to achieve a relatively high organic removal efficiency, the application pre-treats the waste salt, strictly controls the particle size, improves the fluidized pyrolysis efficiency, and selectively heats the larger particle waste salt again through microwave heating, so that the organic removal efficiency is high, and it usually takes 1-10 minutes. In addition, the waste salt is basically a non-polar molecule, the microwave pyrolysis selectively heats the polar organic matter and impurity molecules, can accurately control the organic pyrolysis, avoids the non-selective heating of the waste salt and the organic matter by directly using high-temperature flue gas, realizes real-time temperature control, avoids the melting and wall sticking of the ultra-fine salt particles at high temperature, and realizes the best process of the organic removal efficiency and temperature.

[0078] The present application has higher energy consumption than the pure microwave pyrolysis process, but lower than the traditional high-temperature pyrolysis, combines the advantages of both, improves the processing efficiency, and the energy consumption is also optimized, which is 50% to 80% of the energy consumption of the traditional high-temperature pyrolysis process, but the efficiency of organic matter is significantly improved.

[0079] After the treatment of the present application, due to the small particle size of the salt, the dissolution efficiency is high, the salt water has less organic matter after carbon separation, and the pretreated salt water can be used in the chlor-alkali industry, the separated carbon can be dried by recycling the waste heat of the system and then sent out for treatment, or sent into the hot blast furnace as fuel, reducing the consumption of external natural gas, and realizing the comprehensive utilization of waste salt.

[0080] Compared with the traditional rotary kiln high-temperature pyrolysis process, the present application reduces the land occupation and investment, greatly reduces the amount of pyrolysis gas that needs to be incinerated, optimizes the investment and environmental protection cost, and is more conducive to realizing scale and industrialization.

[0081] Overall, the industrial waste salt high-temperature organic matter removal system and method provided by the present application has the following beneficial effects:

[0082] (1) The present application has a significant effect on promoting the pyrolysis of industrial waste salt organic matter by pretreating the industrial raw salt through grinding and controlling the particle size of the raw salt entering the pyrolysis furnace 9 through air separation, compared with the traditional rotary pyrolysis furnace.

[0083] (2) The present application uses a hot blast furnace 7 and a microwave heater 10 to provide pyrolysis energy, and the residual carbon in the salt after pyrolysis under low oxygen conditions needs to be separated from the salt, and the separated carbon has a high calorific value and can be used to supplement the energy of the pyrolysis furnace 9, reducing the consumption of natural gas, and can also be sold as fuel for power plants, boiler plants, etc., which has a good effect on reducing costs.

[0084] (3) The present application uses a Venturi mixer 8 to add fine particle waste salt after grinding into the circulating air, realizing good fluidization and mixing, which is of great significance to improving the pyrolysis efficiency. In addition, larger particles in the pyrolysis furnace 9 can also be returned to the Venturi mixer 8, and the circulating high-temperature pyrolysis can improve the removal and conversion of organic matter.

[0085] (4) The present application strengthens the control of pyrolysis temperature by the microwave heater 10, avoids the excessive melting of waste salt at high temperature, and the waste salt adheres to the surface of the flue and corrodes the flue material. Precise control of the pyrolysis temperature helps to realize the organic combination of waste salt pyrolysis temperature and efficiency, improve the pyrolysis efficiency, and optimize the energy consumption.

[0086] (5) The application adopts a closed system, and the flue gas is recycled in three ways: one way of flue gas enters the combined burner 701 of the hot blast furnace 7, which can reduce the amount of nitrogen oxides generated by natural gas; one way enters the mill 6, as the waste salt air selection and conveying carrier gas in the mill 6 passes through the Venturi mixer 8 into the pyrolysis system; the last way of flue gas enters the rotary dryer 4 through the feeder 3 to dry the industrial waste salt, and after the tail gas is separated from the solid, the tail gas is sent to the incineration safety treatment. Flue gas recycling is of great significance to energy saving and consumption reduction.

[0087] (6) Compared with the traditional wet method and high-temperature melting method for removing organic matter, the application has the advantages of small occupied area, low operation cost, environmental friendliness, high efficiency of organic matter removal, and far-reaching significance for large-scale industrial waste salt resource utilization.

[0088] (7) The industrial waste salt high-temperature organic matter removal system of the application is an organic integration of hot blast furnace, pretreatment system, pyrolysis system, energy recovery system, gas-solid separation system and salt making system, which can be used for harmless, reduction and resource disposal of industrial waste salt, and has the advantages of high system integration, small occupied area, high thermal efficiency, small environmental pollution, low production cost and obvious economic benefit.

[0089] Each embodiment in the specification is described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts between each embodiment can be referred to each other.

[0090] The above describes in detail the industrial waste salt high-temperature organic matter removal system and method provided by the application. The principles and implementation modes of the application are described by applying specific examples. The above embodiment is only used to help understand the method and core idea of the application. It should be pointed out that for ordinary skilled in the art, without departing from the principles of the application, the application can be improved and modified in several ways, and these improvements and modifications also fall within the protection scope of the claims of the application.

Claims

1. A high-temperature organic matter removal system for industrial waste salt, characterized in that: include: A pretreatment system for pretreating industrial waste salt to form a gas-solid mixture; a pyrolysis system, connected to the pretreatment system and configured to receive the gas-solid mixture, wherein the pyrolysis system is configured to pyrolyze the gas-solid mixture; an energy recovery system, connected to the pyrolysis system, for recovering heat generated by pyrolysis of the gas-solid mixture; a gas-solid separation system, connected to the pyrolysis system, the gas-solid separation system being used to decompose the gas-solid mixture into gas and solid; The salting system is connected to the gas-solid separation system, and the salting system is used to salt the decomposed solids.

2. The high-temperature organic matter removal system for industrial waste salt according to claim 1 is characterized in that: The pretreatment system comprises a dispersing machine (1), an air-locking discharge valve (2), a feeder (3), a rotary dryer (4), a grinder (6) and a cyclone dust collector (5) which are connected in sequence. The dispersing machine (1) is used to preheat and dispersing the industrial waste salt. The air-locking discharge valve (2) is used to prevent the gas in the feeder (3) from flowing back to the dispersing machine (1). The feeder (3) is provided with an air inlet (302). The rotary dryer (4) is used to dry the gas-solid mixture therein. The grinder (6) is used to grind the gas-solid mixture. The cyclone dust collector (5) is used to absorb the exhaust gas in the grinder (6).

3. The high-temperature organic matter removal system for industrial waste salt according to claim 2 is characterized in that: The dispersing machine (1) is provided with a dispersing machine feed port (101), a dispersing machine discharge port (102), a circulating water heating jacket and an exhaust gas discharge port (105); the circulating water heating jacket is provided with a jacket water inlet (103) and a jacket water outlet (104); the jacket water inlet (103) is used to introduce hot circulating water into the circulating water heating jacket; the jacket water outlet (104) is used to discharge the hot circulating water after cooling; the material valve inlet (201) of the air lock discharge valve (2) is communicated with the dispersing machine discharge port (102); the material valve outlet (202) of the air lock discharge valve (2) is communicated with the feeder feed port (301) of the feeder (3); and the feeder (3) is further provided with a feeder air inlet (303) communicated with the exhaust gas discharge port (105).

4. The high-temperature organic matter removal system for industrial waste salt according to claim 3 is characterized in that: The rotary dryer (4) includes a salt dust outlet (401) and a dryer discharge port (402); the cyclone dust collector (5) includes a dust collector feed port (501), a dust collector outlet (502) and a double hammer flap valve (503); the mill (6) includes a coarse salt feed port (601), a salt powder feed port (602), a mill air inlet (603), a gas-solid mixture air outlet (604), a circulating water inlet (605), a circulating water return outlet (606), a grinding roller (607) and a dynamic separator (608); The salt dust outlet (401) is connected to the dust collector feed port (501), the dryer discharge port (402) is connected to the coarse salt feed port (601), the salt powder feed port (602) is connected to the double hammer flap valve (503), the circulating water inlet (605) is connected to the water supply component, the circulating water return outlet (606) is connected to the jacket water inlet (103), and the grinding roller (607) and the dynamic separator (608) are both arranged inside the grinding mill (6).

5. The high-temperature organic matter removal system for industrial waste salt according to claim 4 is characterized in that: The pyrolysis system includes a hot blast furnace (7), a Venturi mixer (8), a pyrolysis furnace (9) and a microwave heater (10). The hot blast furnace (7), the Venturi mixer (8) and the pyrolysis furnace (9) are connected in sequence. The two ends of the microwave heater (10) are connected to the Venturi mixer (8) and the pyrolysis furnace (9) respectively. The hot blast furnace (7) is used to produce hot blast and introduce hot blast into the Venturi mixer (8). The Venturi mixer (8) is connected to the mill (6) and is used to receive the gas-solid mixture in the mill (6) and the hot blast from the hot blast furnace (7), so that the gas-solid mixture is pyrolyzed in the pyrolysis furnace (9). The microwave heater (10) is used to heat the return material from the pyrolysis furnace (9) to the Venturi mixer (8).

6. The high-temperature organic matter removal system for industrial waste salt according to claim 5 is characterized in that: The hot blast furnace (7) includes a combined burner (701) and a high-temperature flue gas outlet (702); the venturi mixer (8) includes a high-temperature flue gas inlet (801), a mixer air inlet (802), a mixer feed port (803) and a mixer discharge port (804); the pyrolysis furnace (9) includes a pyrolysis furnace feed port (901), a pyrolysis furnace mixing outlet (902) and a pyrolysis furnace return port (903); the combined burner (701) is used to produce hot blast. The high-temperature flue gas outlet (702) is connected to the high-temperature flue gas inlet (801), the mixer air inlet (802) is connected to the gas-solid mixture air outlet (604), the mixer feed port (803) is connected to the first end of the microwave heater (10), the mixer discharge port (804) is connected to the pyrolysis furnace feed port (901), and the pyrolysis furnace return port (903) is connected to the second end of the microwave heater (10).

7. The high-temperature organic matter removal system for industrial waste salt according to claim 6 is characterized in that: The energy recovery system comprises an air preheater (11), and the air preheater (11) comprises an air preheater air inlet (1101), an air preheater air outlet (1102), a cold air inlet (1103) and a hot air outlet (1104). The air preheater air inlet (1101) is connected to the pyrolysis furnace mixing outlet (902), the cold air inlet (1103) is connected to the air outlet of the blower (15), and the hot air outlet (1104) is connected to the hot air furnace (7).

8. The high-temperature organic matter removal system for industrial waste salt according to claim 7, characterized in that: The gas-solid separation system comprises a cyclone separator (12) and a dust collector (13); the cyclone separator (12) comprises a separator air inlet (1201), a separator air outlet (1202), and a weight hammer flap valve outlet (1203); the dust collector (13) comprises a dust collector air inlet (1301), a dust collector air outlet (1302), and a bottom flap valve outlet (1303); the separator air inlet (1201) is communicated with the air preheater air outlet (1102); the separator air outlet (1202) is communicated with the dust collector air inlet (1301); and the dust collector air outlet (1302) is communicated with the combined burner (701).

9. The high-temperature organic matter removal system for industrial waste salt according to claim 8, characterized in that: The salting system comprises a salting tank (14), wherein the salting tank (14) is provided with a first feed port (1401) and a second feed port (1402), wherein the first feed port (1401) is communicated with the discharge port (1203) of the weight hammer flap valve, and the second feed port (1402) is communicated with the discharge port (1303) of the bottom flap valve. The salting tank (14) is further provided with a water inlet (1403), a water outlet (1404), an overflow weir (1405) and an agitator (1406).

10. A method for removing organic matter from industrial waste salt at high temperature, applicable to the industrial waste salt high temperature removal of organic matter system according to claim 9, characterized in that: include: Step S1, preheating the hot air furnace (7) and the pyrolysis furnace (9); Step S2, introducing production water into the salting tank (14), and introducing circulating water into the circulating water inlet (605); Step S3, starting the blower (15) and igniting the hot air furnace (7); Step S4, starting the stirrer (1406), the microwave heater (10), the grinder (6), the rotary dryer (4), the air lock discharge valve (2) and the disintegrator (1) in sequence at intervals of 30 seconds; Step S5, introducing industrial waste salt into the breaker (1); Step S6, after sufficient pyrolysis salts are accumulated at the bottom of the cyclone separator (12), the pyrolysis salts enter the salting tank (14) through the discharge port (1203) of the weight hammer flap valve; Step S7, continuously adding production water to the salt tank (14), and when the overflow level is reached, monitoring the density of the salt solution, and after reaching the required level, determining the amount of production water to be added based on the overflow volume to ensure water balance and salt solution concentration requirements; Step S8: recovering the salt solution to remove impurities and separate salt.

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