Low-temperature pyrolysis treatment system for waste salt containing organic matters

Abstract

The utility model provides a low-temperature pyrolysis treatment system for organic matter-containing waste salt, which is characterized in that the organic matter-containing waste salt is firstly crushed, screened and granulated by a waste salt pretreatment unit, the organic matter-containing waste salt with the particle size reaching the standard is fed into a low-temperature pyrolysis device for low-temperature pyrolysis, and flue gas generated in the pyrolysis process enters a flue gas treatment unit; sequentially performing combustion, waste heat recovery and utilization and purification and then discharging, and treating the pyrolyzed waste salt in a waste salt recovery unit to finally obtain finished salt meeting the product standard. The low-temperature pyrolysis treatment system can realize continuous treatment of waste salt containing organic matters, has the advantages of high organic matter removal rate and low operation energy consumption, does not generate wastes in the whole operation process, does not discharge toxic and harmful gases, and has remarkable advantages.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of waste salt pyrolysis treatment, further relates to a low temperature pyrolysis treatment system of organic matter containing waste salt. BACKGROUND

[0002] The chemical waste salt mainly includes solid, semi-solid or salt-containing waste liquid containing toxic and harmful substances generated in the production or waste water treatment of pesticide, medicine, printing and dyeing, coal chemical industry and synthetic resin enterprises. According to the different production nodes, the waste salt of pesticide, medicine and printing and dyeing industry basically belongs to chemical reaction salt or neutralization treatment salt, and the waste salt of coal chemical industry mostly belongs to concentrated salt. Due to the misclassification of the source of high-salt waste water, the waste water containing various salts and other impurities enters the evaporation treatment section, resulting in large production of mixed salt or salt containing a large amount of organic pollutants.

[0003] The main treatment methods of organic matter containing waste salt include extraction method, ocean dumping method, safe landfill method and heat treatment. The advantages and disadvantages of various treatment methods are as follows:

[0004] (1) Extraction method, the treatment principle is to use organic extractant to extract organic matter in by-product salt into extractant, so as to reduce the content of organic pollutants in by-product salt, and the organic matter in extractant can be recycled by back extraction; The disadvantage is that for the case of high organic matter content, a part of organic products can be recovered, but the cost is high, and the treatment effect is poor.

[0005] (2) Ocean dumping method is only suitable for waste salt after harmless treatment, and the waste salt as hazardous waste directly poured into the ocean will cause serious environmental risk.

[0006] (3) Due to the characteristics of waste salt, safe landfill method must enter rigid landfill site, so as to greatly improve the landfill cost, which is as high as 4000 yuan / ton, or even higher.

[0007] (4) Heat treatment method: heat treatment method is divided into low temperature pyrolysis technology and high temperature melting technology, low temperature pyrolysis technology is to control the temperature below the melting point (800 DEG C) of inorganic salt, so that the organic matter is converted into pyrolysis gas and then removed. High temperature melting technology is to set the temperature above the melting point of inorganic salt, so that the waste salt reaches the molten state. High temperature melting requires high equipment, and the treatment cost is relatively high, but the organic matter removal effect is good. Low temperature pyrolysis method has good effect on complex organic pollutants, low energy consumption, and has been widely studied for a long time. Low temperature pyrolysis technology can realize the purpose of waste salt resource utilization, and the purified waste salt can be used for caustic soda industry and preparation of snow melting agent, and the treatment cost is also relatively low.

[0008] Patent CN215543624U discloses a harmless treatment device for organic matter-containing waste salt, which includes a crushing device, a preheating device, a microwave pyrolysis system, a tail gas treatment device, a dissolution and filtration device, and an evaporation device. The technical difference between this technical route and the conventional heat treatment method is mainly reflected in the use of a preheating treatment (rotary kiln) and a microwave pyrolysis two-stage heating method. The specific process is as follows: the organic matter-containing waste salt to be treated enters the crushing device, is crushed into granular material, and then enters the preheating device for heating to 350-500°C. After that, the granular material is transported to the microwave pyrolysis system, where it is heated to 600-650°C under the microwave radiation of a 50-75 kW high-power microwave source. At this temperature, the organic matter in the granular material is pyrolyzed. In the examples, a multifunctional rotating bed structure can be used. During microwave heating, the material can be tumbled at multiple angles inside the bed, allowing it to uniformly absorb microwaves and undergo pyrolysis. However, this technology has the following problems: (1) The microwave pyrolysis technology is relatively difficult to implement and requires high operating skills; (2) It is difficult to scale up for large-scale promotion, as uniform heating of the material becomes challenging and the overall energy consumption is high; (3) The light density of the waste salt particles makes them easily carried away by the downstream suction of the fan, reducing the overall treatment efficiency.

[0009] Patent CN218261991U discloses a resource utilization system for high-organic-content waste salt, which effectively solves the problem of recycling high-organic-content waste salt through a composite treatment method. The treatment process includes: crushing and screening the high-organic-content waste salt, drying and preheating, then sending it to a calcination and melting system for secondary calcination and melting treatment, cooling and dissolving the melted waste salt, adding calcium chloride for precipitation and flocculation, then sending it to a plate and frame filter system to remove solids, sending the filtered brine to an inorganic membrane system for filtration, and sending the filtered brine to an MVR system for evaporation and crystallization to obtain standard industrial salt. The difference between the waste salt treatment technology route of this patent and the conventional route is mainly the use of a preheating and melting calcination process route, i.e., drying with a hot air circulation dryer and then calcining in a melting furnace. The advantage of this technology is that the organic matter in the waste salt can be completely pyrolyzed, and the quality of the resulting salt is high. However, it also has the following problems: (1) The melting calcination temperature requirement is high, and the system's energy consumption is large; (2) The molten salt severely erodes the refractory materials, resulting in high operating costs and making it difficult to run continuously for a long period.

[0010] Patent CN114192557A discloses a method and device for disposing organic-containing waste salt in a two-stage reaction furnace, which comprises a feeding hopper, a crusher is arranged at the lower end of the feeding hopper, a conveyor belt is connected at the lower end of the crusher, and a reaction furnace is connected at the other end of the conveyor belt. Compared with the traditional waste salt disposal process, the industrial waste salt is more thoroughly disposed of due to the high-temperature plasma incineration and the fluidized state of the waste salt during disposal. The patent and patent CN218261991U have similar heat treatment methods, both of which use heat sources to heat the waste salt into a molten state, and the organic matter is fully pyrolyzed and incinerated. The only difference is that the heating method is in the form of plasma, so the problems of the two patents are basically the same. Utility model content

[0011] In view of the problems of high energy consumption and low treatment efficiency of the existing organic-containing waste salt treatment device, the purpose of the utility model is to provide a low-temperature pyrolysis treatment system for organic-containing waste salt, which comprises a waste salt pretreatment unit, a low-temperature pyrolysis device, a waste salt recovery unit and a flue gas treatment unit. The waste salt pretreatment unit crushes and sieves the organic-containing waste salt, and the organic-containing waste salt with a particle size that meets the standard is sent to the low-temperature pyrolysis device for low-temperature pyrolysis, while the organic-containing waste salt with a particle size that does not meet the standard is granulated, and after meeting the standard, it is subjected to low-temperature pyrolysis. The flue gas generated in the pyrolysis process enters the flue gas treatment unit, and is sequentially subjected to combustion, waste heat recovery and utilization and purification before being discharged. The waste salt after pyrolysis enters the waste salt recovery unit for treatment, and finally the finished product salt meeting the product standard is obtained. The low-temperature pyrolysis treatment system can realize continuous treatment of organic-containing waste salt, and the low-temperature pyrolysis has the advantages of high organic matter removal rate and low operating energy consumption. The flue gas generated in the low-temperature pyrolysis process is discharged after waste heat utilization and purification, and there is no toxic and harmful gas emission. The entire operation process basically generates no waste, is beneficial to the environment, and has extremely high popularization and application value.

[0012] In order to achieve the above-mentioned purpose, the utility model provides the following technical scheme:

[0013] A low-temperature pyrolysis treatment system for organic-containing waste salt, comprising: a waste salt pretreatment unit, a low-temperature pyrolysis device, a waste salt recovery unit and a flue gas treatment unit; the waste salt pretreatment unit is used for treating the organic-containing waste salt to a preset particle size; the low-temperature pyrolysis device is connected with the waste salt pretreatment unit and is used for low-temperature pyrolysis of the organic-containing waste salt; the waste salt recovery unit is in communication with the low-temperature pyrolysis device and is used for treating the waste salt after low-temperature pyrolysis to finished product salt; and the flue gas treatment unit is in communication with the low-temperature pyrolysis device and is used for treating the flue gas generated in the low-temperature pyrolysis process so that the flue gas meets the emission requirements.

[0014] In some embodiments, the waste salt pretreatment unit comprises a crushing device, a screening device, a granulating device, and a bin; the crushing device, the screening device, and the bin are connected in sequence; the granulating device is connected with the screening device and the bin respectively, and is used for granulating the waste salt containing organic matters with a particle size less than the preset particle size until the particle size reaches the preset particle size.

[0015] In some embodiments, the low-temperature pyrolysis device comprises an indirect heating pyrolysis rotary kiln, which comprises an inner cylinder and an outer cylinder; the inner cylinder is used for containing the waste salt containing organic matters, and is provided with a flue gas outlet; the outer cylinder is sleeved on the periphery of the inner cylinder and forms a heat exchange space between the outer wall of the inner cylinder and the outer cylinder for the flow of high-temperature gas.

[0016] In some embodiments, the low-temperature pyrolysis device further comprises a heating burner for providing high-temperature gas to the heat exchange space to indirectly heat the waste salt containing organic matters in the inner cylinder; and / or, the low-temperature pyrolysis device further comprises a rotating device and a supporting device; the rotating device is used for providing power for the rotation of the inner cylinder; the supporting device is used for supporting the indirect heating pyrolysis rotary kiln, and the supporting device comprises at least two supporting members, and the two supporting members are arranged at two ends of the indirect heating pyrolysis rotary kiln.

[0017] In some embodiments, the inner cylinder is provided with a feeding port and a plurality of air distribution ports, the feeding port and the air distribution port are arranged at the same end of the inner cylinder, and the air distribution port is used for introducing an oxidation medium gas required for low-temperature pyrolysis into the inner cylinder; and / or, a plurality of heat transfer plates are arranged on the inner wall and the outer wall of the inner cylinder at intervals, and the inner wall of the inner cylinder and the heat transfer plates are coated with an oxidation catalyst coating.

[0018] In some embodiments, the waste salt recovery unit comprises a cooling device, a waste salt dissolving device, a filtering device, a flocculation and precipitation device, a filter pressing device, and an evaporation and crystallization device connected in sequence; the cooling device is used for cooling the waste salt after pyrolysis; the waste salt dissolving device is used for configuring the waste salt into a waste salt solution; the filtering device is used for filtering and removing impurities in the waste salt solution; the flocculation and precipitation device is used for flocculating and precipitating organic matters or heavy metal impurities in the waste salt solution; the filter pressing device is used for removing flocculation or precipitation in the waste salt solution; and the evaporation and crystallization device is used for evaporating and crystallizing the waste salt solution to obtain finished salt.

[0019] In some embodiments, the flue gas treatment unit comprises: a secondary incineration device, a waste heat utilization device and a flue gas purification device connected in sequence; the secondary incineration device is connected with the flue gas outlet of the low-temperature pyrolysis device through an outlet flue, and is used for burning and treating the flue gas generated in the low-temperature pyrolysis process; the waste heat utilization device is used for recovering the heat of the high-temperature flue gas; and the flue gas purification device is used for purifying the flue gas.

[0020] In some embodiments, the screening device is a vibrating screening machine; and / or, the granulating device is a roller granulating machine; and / or, the low-temperature pyrolysis treatment system further comprises: a feeding device in communication with the waste salt pretreatment unit and the low-temperature pyrolysis device respectively, and used for providing power for conveying the waste salt containing organic matters.

[0021] In some embodiments, the secondary incineration device is a two-burning-chamber or a regenerative thermal incinerator; and / or, the flue gas purification device comprises: a quenching tower, an acid removal tower, a flue gas dust remover and a denitration tower.

[0022] In some embodiments, the cooling device is a water-cooled slag cooler; and / or, the filter pressing device is a plate-and-frame filter press; and / or, the evaporation crystallization device is an MVR evaporator or a multiple-effect evaporator.

[0023] Compared with the prior art, the low-temperature pyrolysis treatment system for waste salt containing organic matters has the following beneficial effects:

[0024] 1. The waste salt pretreatment unit changes the physical form of the waste salt containing organic matters, so that the waste salt containing organic matters with a preset particle size can avoid being carried by flue gas to cause insufficient pyrolysis, the residence time of the waste salt in the low-temperature pyrolysis device is increased, and the purification efficiency of the waste salt is improved.

[0025] 2. The low-temperature pyrolysis technology is adopted, the energy consumption is reduced to the maximum extent while the efficient organic matter removal rate is met, the problem of erosion of the waste salt on the refractory material after melting is avoided, and the investment and operation cost is reduced.

[0026] 3. The low-temperature pyrolysis device adopts an indirect heating mode, provides a stable flow field environment for heating the waste salt containing organic matters, avoids the problem of uneven heating of the waste salt caused by blowing of fuel such as natural gas, and improves the treatment efficiency.

[0027] 4. The low-temperature pyrolysis system can realize continuous feeding and discharging, and can keep high efficiency and continuous operation, has low operation cost, high production efficiency, and can obtain finished salt through harmless and resourceful treatment of the waste salt after pyrolysis, can realize standard emission through waste heat utilization and purification treatment after combustion of the flue gas generated during pyrolysis, and has no waste during the whole operation process, reduces pollution to the environment, and has remarkable economic and environmental benefits. BRIEF DESCRIPTION OF DRAWINGS

[0028] The above characteristics, technical features, advantages and implementation manners of the present application will be further described in the following manner in combination with the drawings.

[0029] Figure 1 A structure diagram of the low-temperature pyrolysis device provided by the present application is shown in the figure.

[0030] Figure 2 A side view of the inner cylinder provided by the present application is shown in the figure.

[0031] Figure 3 A sectional view of the inner cylinder provided by the present application is shown in the figure.

[0032] Figure 4 A process flow diagram of the low-temperature pyrolysis system provided by the present application is shown in the figure.

[0033] BRIEF DESCRIPTION OF DRAWINGS

[0034] 1 - silo; 2 - feeding device; 3 - transmission device;

[0035] 4 - indirect heating type pyrolysis rotary kiln; 401 - inner cylinder; 402 - outer cylinder; 403 - feeding port; 404 - air distribution port; 405 - internal heat transfer plate; 406 - external heat transfer plate;

[0036] 5 - organic matter containing waste salt; 6 - first support; 7 - second support; 8 - outlet flue; 9 - secondary incineration device; 10 - secondary incineration device burner; 12 - cooling device; 13 - heating burner. DETAILED DESCRIPTION

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the specific implementation manners of the present application will be described in combination with the drawings. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to these drawings without creative labor, and other embodiments can also be obtained.

[0038] For the sake of simplicity of the drawings, only parts related to the utility model are shown in the drawings, which do not represent the actual structure of the product. In addition, in order to make the drawings simple and easy to understand, in some drawings, only one of the parts with the same structure or function is shown or only one of them is marked. In this text, "one" not only means "only one", but also means "more than one".

[0039] It should be further understood that the term "and / or" used in the utility model specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0040] In this text, it should be noted that, unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication inside two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0041] In addition, in the description of the utility model, the terms "first", "second" and the like are only used for distinction, and cannot be understood as indicating or implying relative importance.

[0042] Embodiment 1

[0043] The utility model provides a kind of low temperature pyrolysis processing system of organic matter containing waste salt, comprising: waste salt pretreatment unit, low temperature pyrolysis device, waste salt recovery unit and flue gas treatment unit.Specifically:

[0044] Waste salt pretreatment unit is used to treat organic matter containing waste salt to preset particle size, preferably, preset particle size is 1 ~ 50mm.

[0045] Low temperature pyrolysis device is connected with waste salt pretreatment unit, and organic matter containing waste salt meeting preset particle size is carried out low temperature pyrolysis.

[0046] Waste salt recovery unit is communicated with low temperature pyrolysis device, and waste salt after low temperature pyrolysis is treated to finished product salt.

[0047] Flue gas treatment unit is communicated with low temperature pyrolysis device, and is used to treat the flue gas generated in low temperature pyrolysis process, so that flue gas meets emission requirements.

[0048] In some embodiments, in combination Figure 1 And Figure 4As shown, the waste salt pretreatment unit includes a crushing device, a screening device, a granulating device, and a bunker 1. The crushing device, the screening device, and the bunker 1 are sequentially connected, and the granulating device is connected with the screening device and the bunker 1 respectively. After the particle size of the screened waste salt containing organic matters meets the preset particle size, the waste salt is directly sent to the bunker 1 for low-temperature pyrolysis. When the particle size of the waste salt containing organic matters does not meet the preset particle size, i.e., the particle size is smaller than the preset particle size, the waste salt is sent to the granulating device for granulation until the particle size meets the preset particle size and then the waste salt is sent to the bunker 1. The granulation can increase the particle size and density of the waste salt containing organic matters, so as to increase the residence time of the waste salt in the low-temperature pyrolysis device, avoid being carried by flue gas, and reduce the removal efficiency of organic matters.

[0049] Further, the screening device is preferably a vibrating screening machine.

[0050] The granulating device is preferably a roller granulator.

[0051] Further, the low-temperature pyrolysis treatment system further includes a feeding device 2, which is in communication with the waste salt pretreatment unit and the low-temperature pyrolysis device respectively and is mainly used for power transmission of the waste salt containing organic matters. Specifically, the feeding device 2 is in communication with the outlet of the bunker 1 and the inlet of the low-temperature pyrolysis device respectively, and the waste salt containing organic matters with a standard particle size is sent to the low-temperature pyrolysis device for low-temperature pyrolysis.

[0052] The feeding device 2 is preferably a screw feeder.

[0053] In some embodiments, as shown, Figure 1 As shown, the low-temperature pyrolysis device includes an indirect heating type pyrolysis rotary kiln 4, which includes an inner cylinder 401 and an outer cylinder 402. The inner cylinder 401 is used for containing the waste salt containing organic matters 5. The inner cylinder 401 is provided with a flue gas outlet. The outer wall of one end of the inner cylinder 401 is provided with a feeding port 403, and the outer wall of the other end is provided with a discharging port.

[0054] The outer cylinder 402 is sleeved on the periphery of the inner cylinder 401 and forms a heat exchange space between the outer wall of the inner cylinder 401 for the flow of high-temperature gas.

[0055] The heat source of the indirect heating type pyrolysis rotary kiln 4 is the high-temperature gas flowing in the heat exchange space. The high-temperature gas heats the inner cylinder 401 and then heats the waste salt containing organic matters 5 inside. There is no heating source inside the indirect heating type pyrolysis rotary kiln 4, which avoids the interference of the high-temperature gas on the smooth pyrolysis of the waste salt, provides sufficient residence time and stable flow field, and ensures the sufficient pyrolysis of the waste salt.

[0056] The indirect heating pyrolysis rotary kiln 4 can be selected to have no lining or lining according to the corrosion performance of the material. In the case of no corrosion, high-temperature alloy steel can be used to improve the heat transfer efficiency. In the case of corrosion, the lining thickness of the refractory material is 10-20 mm.

[0057] Preferably, the melting temperature of the organic matter-containing waste salt 5 is generally lower than that of the pure waste salt. For the indirect heating pyrolysis rotary kiln 4, the low-temperature pyrolysis temperature is generally set to 450-700°C. If the temperature is too low, the pyrolysis efficiency will be affected. If the temperature is too high, the waste salt melting will increase the processing cost and disposal difficulty.

[0058] Further, the low-temperature pyrolysis device further comprises a heating burner 13, which is mainly used to provide high-temperature gas to the heat exchange space to indirectly heat the organic matter-containing waste salt 5 in the inner cylinder 401. Preferably, the heating burner 13 is arranged at the bottom of the indirect heating pyrolysis rotary kiln 4, i.e., the bottom of the outer cylinder 402.

[0059] Preferably, the heating mode of the heating burner 13 can adopt various heating forms such as gas, oil, and electric heating. The heating temperature of the heating burner 13 is 600-650°C.

[0060] Further, the low-temperature pyrolysis device further comprises a rotating device 3 and a supporting device. The rotating device 3 is used to provide power for the rotation of the inner cylinder 401, and is preferably arranged at a position close to the inlet of the inner cylinder 401.

[0061] The supporting device is used to support the indirect heating pyrolysis rotary kiln 4. The supporting device comprises at least two supporting members, and the two supporting members are arranged at two ends of the indirect heating pyrolysis rotary kiln 4.

[0062] More specifically, as shown in Figure 1 , the supporting device can be divided into a first supporting member 6 and a second supporting member 7. The first supporting member 6 and the second supporting member 7 are arranged at two ends of the inner cylinder 401 in the length direction and support the inner cylinder 401.

[0063] Further, a plurality of air distribution ports 404 are arranged on the side wall of the inner cylinder 401 where the feeding port 403 is located, i.e., the air distribution port 404 and the feeding port 403 are arranged at the same end of the inner cylinder 401. The plurality of air distribution ports 404 are uniformly arranged and used to transport the oxidation medium gas into the inner cylinder 401 to provide the oxidation medium gas for the low-temperature pyrolysis process. The outlet air pressure of the air distribution port 404 is not more than 100 Pa. As shown in Figure 2 , the air distribution port 404 provided in the embodiment is arranged in four and is symmetrically arranged along the central axis of the inner cylinder 401.

[0064] The oxidation medium is preferably pure oxygen or air.

[0065] Further, as shown in Figure 3 the inner wall and the outer wall of the inner cylinder 401 are both provided with a plurality of heat transfer plates arranged at intervals, which are specifically divided into internal heat transfer plates 405 provided on the inner wall and external heat transfer plates 406 provided on the outer wall. The heat transfer plates can increase the heat transfer area of the inner and outer cold and hot mediums, and the material of the heat transfer plates is metal. The heat transfer plates can be selected in various structural forms. The heat transfer plates can also play a role in mixing and stirring the organic-containing waste salt 5 when the inner cylinder 401 rotates, and can increase the heating area and make the organic-containing waste salt 5 more evenly heated.

[0066] Further, the inner wall of the inner cylinder 401 and the heat transfer plates are both coated with an oxidation catalyst coating to improve the decomposition of the organic matter in the waste salt.

[0067] In some embodiments, as shown in Figure 4 the waste salt recovery unit comprises: a cooling device 12, a waste salt dissolving device, a filtering device, a flocculation and precipitation device, a filter pressing device, and an evaporation and crystallization device connected in sequence.

[0068] The cooling device 12 is used to cool the waste salt after pyrolysis, the waste salt dissolving device is used to configure the waste salt into a waste salt solution, the filtering device is used to filter and remove impurities in the waste salt solution, which are refractory materials and the like falling off in the low-temperature pyrolysis process, the flocculation and precipitation device is used to flocculate and precipitate organic matter or heavy metal impurities in the waste salt solution, the filter pressing device is used to remove flocculants or precipitates in the waste salt solution, and the evaporation and crystallization device is used to evaporate and crystallize the waste salt solution to obtain finished salt.

[0069] Further, the cooling device 12 is preferably a water-cooled slag cooler.

[0070] The filter pressing device is preferably a plate-and-frame filter press.

[0071] The evaporation and crystallization device is preferably an MVR evaporator or a multiple-effect evaporator.

[0072] In some embodiments, as shown in Figure 1 and Figure 4 the flue gas treatment unit comprises: a secondary incineration device 9, a waste heat utilization device, and a flue gas purification device connected in sequence.

[0073] The secondary incineration device 9 is connected with the flue gas outlet (the flue gas outlet of the inner cylinder 401) of the low-temperature pyrolysis device through the outlet flue 8 to burn and treat the flue gas generated in the low-temperature pyrolysis process.

[0074] The burned flue gas enters the waste heat utilization device, and then enters the flue gas purification device after recovering heat. The flue gas is purified and treated, and then discharged after reaching the emission standard.

[0075] Further, the flue gas treatment unit further comprises a secondary incineration device burner 10 for providing flue gas combustion support for the secondary incineration device 9.

[0076] The secondary incineration device 9 is preferably a double combustion chamber or a regenerative thermal incinerator.

[0077] The flue gas purification device comprises a quenching tower, an acid removal tower, a flue gas dust remover and a denitration tower.

[0078] In summary, in combination with the above Figure 1 and Figure 4 As shown in the figure, the operation process of the low-temperature pyrolysis treatment system is briefly described as follows:

[0079] The crushing device crushes the organic matter-containing waste salt, and then the screening device screens the organic matter-containing waste salt.

[0080] The organic matter-containing waste salt 5 in the bunker 1 enters the inner cylinder 401 through the feeding device 2 for low-temperature pyrolysis, and the generated pyrolysis gas enters the secondary incineration device 9 through the outlet flue 8.

[0081] The waste salt after pyrolysis in the inner cylinder 401 is first cooled by the cooling device, and then enters the waste salt dissolving device after being cooled to 50-60℃ for dissolving.

[0082] Example 2

[0083] On the basis of Example 1, this embodiment provides a specific example to illustrate the operation process of the low-temperature pyrolysis treatment system.

[0084] The organic matter-containing waste salt provided by the embodiment is waste salt generated by an epichlorohydrin device, wherein the NaCl content is greater than or equal to 94%, the hydrocarbon and oxygen oil and fat organic matter is less than or equal to 6%, and the low calorific value is 0-100 kcal / kg.

[0085] The organic matter-containing waste salt 5 enters a crushing device for crushing, and the particle size of the crushed waste salt is 1-50 mm, meeting the preset particle size requirement for entering the furnace.

[0086] The crushed organic matter-containing waste salt 5 enters a screening device. The undersize waste salt with a particle size less than 1 mm enters a granulating device for granulation, and the oversize waste salt with a particle size greater than 50 mm returns to the crushing device for re-crushing. After granulation, the particle size of the granulated organic matter-containing waste salt 5 is 20 mm, and the granulation density is 1.8-2.0 g / cm 3 . The organic matter-containing waste salt 5 meeting the preset particle size requirement is sent into a bunker 1.

[0087] A feeding device 2 sends the organic matter-containing waste salt 5 in the bunker 1 to an indirectly heated pyrolysis rotary kiln 4 for low-temperature pyrolysis treatment. The pyrolysis temperature is determined according to the composition of the organic matter-containing waste salt 5. Since the main component of the organic matter-containing waste salt treated in the embodiment is NaCl, the pyrolysis temperature of the indirectly heated pyrolysis rotary kiln 4 is set to 600 DEG C.

[0088] The organic matter-containing waste salt 5 enters the inner cylinder 401 for pyrolysis, and the pyrolysis residence time is generally 60-90 min. After pyrolysis, the residual TOC is less than 80 ppm.

[0089] The high-temperature flue gas generated in the pyrolysis process enters a secondary incineration device 9 for further combustion treatment. The combustion temperature of the secondary incineration device 9 is 1100 DEG C, and the residence time is 2 s, so as to ensure the sufficient combustion of the organic matter. The flue gas after combustion enters a waste heat recovery device to recover the heat of the flue gas, and produce 1.0 Mpa, 182 DEG C saturated steam. The temperature of the flue gas after heat exchange is reduced to about 500 DEG C, and then the flue gas enters a quenching tower for quenching treatment. The quenching tower uses a double-fluid atomizing spray gun to rapidly reduce the temperature to below 200 DEG C, so as to avoid the secondary formation of dioxin. After quenching, the flue gas enters a bag-type dust collector for dust removal. The bag uses a composite filter bag for denitration and dioxin removal. The flue gas after dust removal and denitration is discharged up to the standard.

[0090] The waste salt discharged from the indirectly heated pyrolysis rotary kiln 4 enters a water-cooled slag cooler, is cooled to 50-60 DEG C, and then enters a waste salt dissolving device for dissolving, to form a waste salt solution with a concentration of 20%-25%. The waste salt solution is filtered through multiple stages to remove impurities, and then organic matter in the waste water is reduced by adding a flocculating agent. The waste salt solution after removal of flocculating matter by pressure filtration enters an evaporation crystallization device for evaporation, and finally sodium chloride meeting the product standard is obtained.

[0091] The above merely is preferred implementation manner of the present application, it should be pointed out, for ordinary skilled person in the technical field, on the premise of not departing from the principle of the present application, can also make several improvements and refinements, these improvements and refinements also should be regarded as the protection scope of the present application.

Claims

1. A low-temperature pyrolysis treatment system for waste salt containing organic matter, characterized in that, include: Waste salt pretreatment unit, low-temperature pyrolysis device, waste salt recovery unit and flue gas treatment unit; The waste salt pretreatment unit includes a crushing device, a screening device, a granulation device, and a silo. The crushing device, the screening device, and the silo are connected in sequence. The granulation device is connected to the screening device and the silo respectively, so as to process the waste salt containing organic matter to a preset particle size. The low-temperature pyrolysis device is used to perform low-temperature pyrolysis on the waste salt containing organic matter. The invention includes an indirect heating pyrolysis rotary kiln, comprising an inner cylinder and an outer cylinder; the inner cylinder is used to contain the waste salt containing organic matter, and the inner cylinder is provided with a flue gas outlet; a feed inlet is provided on the outer wall of one end of the inner cylinder, and the outlet of the hopper is connected to the feed inlet; a discharge outlet is provided on the outer wall of the other end of the inner cylinder; the outer cylinder is fitted around the inner cylinder, and a heat exchange space for high-temperature gas flow is formed between the outer cylinder and the outer wall of the inner cylinder. The waste salt recovery unit includes a cooling device, a waste salt dissolving device, a filtration device, a flocculation and sedimentation device, a pressure filter device, and an evaporation and crystallization device connected in sequence. The inlet of the cooling device is connected to the outlet, and it is used to process the waste salt after low-temperature pyrolysis into finished salt. The flue gas treatment unit includes a secondary incineration device, a waste heat utilization device, and a flue gas purification device connected in sequence. The secondary incineration device is connected to the flue gas outlet through an outlet flue and is used to treat the flue gas generated during the low-temperature pyrolysis process so that the flue gas meets the emission requirements.

2. The low-temperature pyrolysis treatment system according to claim 1, characterized in that, The granulation device is used to granulate organic waste salts that are smaller than the preset particle size until the particle size reaches the preset particle size. The granulation device is a roller press granulator.

3. The low-temperature pyrolysis treatment system according to claim 1, characterized in that, The low-temperature pyrolysis device further includes: a heating burner, used to provide high-temperature gas to the heat exchange space to indirectly heat the organic waste salt in the inner cylinder; The low-temperature pyrolysis apparatus further includes: a rotating device and a supporting device; The rotating device is used to provide rotational power for the inner cylinder; The support device is used to support the indirect heating pyrolysis rotary kiln. The support device includes at least two support members, which are respectively disposed at both ends of the indirect heating pyrolysis rotary kiln.

4. The low-temperature pyrolysis treatment system according to claim 1, characterized in that, The inner cylinder is provided with a feed inlet and several air distribution ports. The feed inlet and the air distribution ports are located at the same end of the inner cylinder. The air distribution ports are used to introduce the oxidizing medium gas required for low-temperature pyrolysis into the inner cylinder. The inner wall and the outer wall of the inner cylinder are provided with several heat transfer plates arranged at intervals, and the inner wall of the inner cylinder and the heat transfer plates are coated with an oxidation catalyst coating.

5. The low-temperature pyrolysis treatment system according to claim 1, characterized in that, The flue gas purification device is used to purify flue gas. It includes: quench tower, deacidification tower, flue gas dust collector and denitrification tower.

6. The low-temperature pyrolysis treatment system according to claim 1, characterized in that, The screening device is a vibrating screen. The low-temperature pyrolysis treatment system further includes a feeding device, which is connected to both the waste salt pretreatment unit and the low-temperature pyrolysis device, and is used to provide power for conveying the waste salt containing organic matter.

7. The low-temperature pyrolysis treatment system according to claim 5, characterized in that, The secondary incineration device is a secondary combustion chamber or a regenerative thermal incinerator.

8. The low-temperature pyrolysis treatment system according to claim 1, characterized in that, The cooling device is a water-cooled slag cooler; The filter press is a plate and frame filter press. The evaporation and crystallization device is an MVR evaporator or a multi-effect evaporator.

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