A continuous production system and production process of disperse dye diazo coupling

Abstract

The application provides a continuous diazo coupling production system of disperse dyes, which comprises a diazo feeding unit, a diazo intensifying mixing device, a material inlet of the diazo intensifying mixing device connected with an outlet of the diazo feeding unit, a diazo cooler, a material inlet of the diazo cooler connected with an outlet of the diazo intensifying mixing device, a diazo pipeline reactor, a material inlet of the diazo pipeline reactor connected with a material outlet of the diazo cooler, a coupling feeding unit, a coupling intensifying mixing device, a material inlet of the coupling intensifying mixing device connected with an outlet of the coupling feeding unit and a material outlet of the diazo pipeline reactor, a material inlet of a coupling cooler connected with an outlet of the coupling intensifying mixing device, a coupling pipeline reactor, and a material inlet of the coupling pipeline reactor connected with a material outlet of the coupling cooler. The application has the advantages of stable production process, stable product quality, and reduced wastewater discharge. The application also provides a production process.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of chemical production, and particularly relates to a continuous diazo coupling production system and production process of disperse dyes. BACKGROUND

[0002] As an important product of fine chemical industry, dye products have also developed rapidly with the continuous development of fine chemical industry in China. In the production of traditional dyes, most products involve dangerous processes such as diazo and coupling. At present, the diazo and coupling reactions are mainly produced by batch kettle. The main process is that acid solution and nitrosyl sulfuric acid mixture are first added to the diazo reaction kettle, aromatic amine raw materials are added into the reaction system by stepwise addition, and then aromatic amine, water and surfactant are added into the coupling reaction kettle after the reaction is completed. After mixing uniformly, the diazo reaction material is added into the coupling kettle for coupling reaction. The traditional diazo and coupling reaction mainly has the following problems: 1. The reaction kettle has large volume and large liquid storage capacity, which causes high safety risk of the system; 2. Due to the stepwise addition method, it is impossible to ensure the uniform and constant feeding speed, which causes local reaction temperature to be too high, the reaction system to be non-uniform and the side reactions to be more, and thus the production efficiency and quality cannot be guaranteed; 3. Due to the slow material rate and large change of reaction product solubility, material wrapping is easily formed, which causes incomplete reaction; 4. Due to low control temperature, a large amount of ice is added for cooling, and thus a large amount of water is added for reaction, which causes a large amount of wastewater to be produced and environmental pollution hazards to be formed.

[0003] According to the requirements of the General Administration of Work Safety No. 3

[2017] 1, for process with 4 and 5 level of reaction process risk, especially for projects with high risk but must be industrialized, efforts should be made to optimize the process or change the process to reduce the risk, such as completing the reaction by micro-reaction and continuous flow. Although there are some reports on the continuous flow of fine chemical industry, the technology is mainly used in the laboratory, and there are few successful cases in the industry.

[0004] In the continuous production of diazo and coupling reported in the literature, the reaction raw materials are quantitatively added into the batching kettle, and then overflow into the pipe reactor for reaction. Since the material in the batching kettle has started to react, the problems caused by batch reaction cannot be eliminated. At the same time, the overflow directly enters the pipe reactor, which cannot guarantee the sufficient mixing and reaction of the reaction materials in the pipe reactor, and thus the reaction yield is reduced. SUMMARY

[0005] One of the purposes of the present application is to provide a continuous diazo coupling production system of disperse dyes, which solves the problems existing in the traditional batch production, guarantees the stability of the diazo and coupling reaction production process, and realizes the production safety, stable product quality and reduction of wastewater discharge.

[0006] To solve the above technical problems, the technical scheme adopted by the present application is as follows: a continuous diazo coupling production system of disperse dyes, comprising a diazo reaction unit and a coupling reaction unit, wherein the diazo reaction unit comprises:

[0007] a diazo feeding unit for storing and conveying aromatic amine, nitrosyl sulfuric acid and sulfuric acid;

[0008] a diazo reinforced mixing device, the inlet of which is connected with the outlet of the diazo feeding unit, for intensively mixing the aromatic amine, nitrosyl sulfuric acid and sulfuric acid;

[0009] a diazo cooler, the material inlet of which is connected with the outlet of the diazo reinforced mixing device, for reducing the temperature of diazo liquid;

[0010] a diazo pipeline reactor, the material inlet of which is connected with the material outlet of the diazo cooler, for sufficient reaction of the diazo liquid;

[0011] the coupling reaction unit comprises:

[0012] a coupling feeding unit for storing and conveying surfactant, aromatic amine and water;

[0013] a coupling reinforced mixing device, the inlet of which is connected with the outlet of the coupling feeding unit and the material outlet of the diazo pipeline reactor, for intensively mixing the diazo liquid, surfactant, aromatic amine and water;

[0014] a coupling cooler, the material inlet of which is connected with the outlet of the coupling reinforced mixing device, for reducing the temperature of coupling liquid;

[0015] a coupling pipeline reactor, the material inlet of which is connected with the material outlet of the coupling cooler, for sufficient reaction of the coupling liquid.

[0016] Further, the diazo feeding unit comprises:

[0017] a first solid feeding bin, a weighing device is arranged in the first solid feeding bin, for storing and quantitatively feeding aromatic amine;

[0018] a first automatic feeder, the inlet of which is connected with the outlet of the first solid feeding bin, and the outlet of which is connected with the inlet of the diazo reinforced mixing device through a conveying pipeline, for conveying the quantitatively weighed aromatic amine in the first solid feeding bin;

[0019] a nitrosyl sulfuric acid feeding pipeline, which is connected with the inlet of the diazo reinforced mixing device, for receiving nitrosyl sulfuric acid liquid and conveying it into the diazo reinforced mixing device;

[0020] a sulfuric acid feeding pipe connected with the inlet of the diazotization intensifying mixing device for receiving sulfuric acid liquid and conveying it into the diazotization intensifying mixing device;

[0021] flow metering devices are arranged on the nitrosyl sulfuric acid feeding pipe and the sulfuric acid feeding pipe.

[0022] Further, the coupling feeding unit comprises:

[0023] a second solid feeding bin provided with a weighing device for storing and quantitatively feeding surfactant;

[0024] a second automatic feeder, the inlet of which is connected with the outlet of the second fixed feeding bin, and the outlet of which is connected with the inlet of the coupling intensifying mixing device through a conveying pipe for conveying the quantitatively weighed surfactant from the second solid feeding bin;

[0025] an aromatic amine feeding pipe connected with the inlet of the coupling intensifying mixing device for receiving aromatic amine liquid and conveying it into the coupling intensifying mixing device;

[0026] a water feeding pipe connected with the inlet of the coupling intensifying mixing device for receiving water and conveying it into the coupling intensifying mixing device;

[0027] flow metering devices are arranged on the aromatic amine feeding pipe and the water feeding pipe.

[0028] Further, the first automatic feeder and the second automatic feeder are screw feeders.

[0029] Further, the diazotization intensifying mixing device and the coupling intensifying mixing device are one of a dispersion pump or a homogenizer pump.

[0030] Further, the diazotization cooler and the coupling cooler are both provided with a coolant inlet and a coolant outlet for circulating coolant, and the diazotization cooler is further provided with a diazotization liquid return outlet connected with the inlet of the diazotization intensifying mixing device, and the coupling cooler is further provided with a coupling liquid return outlet connected with the inlet of the coupling intensifying mixing device.

[0031] Further, the diazotization cooler and the coupling cooler are one of a shell-and-tube cooler, a plate cooler or a spiral pipe cooler.

[0032] Further, the diazotization pipe reactor and the coupling pipe reactor are both provided with a heat exchange medium inlet and a heat exchange medium outlet for circulating heat exchange medium.

[0033] Further, the diazo pipeline reactor and the coupling pipeline reactor are one of a tubular reactor, a mixer pipeline reactor or a multi-stage kettle series reactor.

[0034] The second object of the present application is to provide a continuous diazo coupling production process of disperse dyes, comprising:

[0035] The diazo reaction: aromatic amine is added to the first solid feeding bin, weighed and then added to the diazo intensification mixing device through the first automatic feeder, the addition amount of the aromatic amine is controlled in real time by the differential method, the feeding amount of sulfuric acid and nitrosyl sulfuric acid is adjusted by the flow metering device, and they are continuously and stably fed into the diazo intensification mixing device, wherein the feeding molar ratio of the aromatic amine, the nitrosyl sulfuric acid and the sulfuric acid is 1:(1-1.1):(0.5-6); the aromatic amine, the nitrosyl sulfuric acid and the sulfuric acid are fully mixed and reacted in the diazo intensification mixing device to obtain diazo liquid; the diazo liquid is cooled in the diazo cooler, the cooling temperature is between 0 and 5 degrees Celsius, part of the diazo liquid is refluxed to the diazo intensification mixing device after cooling, the reflux ratio is controlled at 2-50, and the remaining diazo liquid is transported to the diazo pipeline reactor for full reaction and then enters the coupling intensification mixing device;

[0036] The coupling reaction: the surfactant is added to the second solid feeding bin, weighed and then added to the coupling intensification mixing device through the second automatic feeder, the addition amount of the surfactant is controlled in real time by the differential method, the feeding amount of water and aromatic amine is adjusted by the flow metering device, and they are continuously and stably fed into the coupling intensification mixing device, wherein the feeding molar ratio of water, aromatic amine and diazo liquid is (100-1000):(0.92-1.02):1, wherein the diazo liquid is calculated based on diazo aromatic amine; the surfactant, water, aromatic amine and diazo liquid are fully mixed and reacted in the coupling intensification mixing device to obtain coupling liquid; the coupling liquid is cooled in the coupling cooler, the cooling temperature is between -3 and 5 degrees Celsius, part of the coupling liquid is refluxed to the coupling intensification mixing device after cooling, the reflux ratio is controlled at 1-5, and the remaining coupling liquid is transported to the coupling pipeline reactor for full reaction and then treated by crystal transformation to obtain disperse dyes.

[0037] Compared with the prior art, the present application has the advantages and beneficial effects that:

[0038] 1. The application changes the original traditional batch production mode of disperse dye diazo and coupling reaction, adopts the mode of series connection of intensifying mixing device, cooler and pipeline reactor, adopts the intensifying mixing device for intensifying mixing reaction, increases the reaction rate, improves the production efficiency, carries out sufficient reaction in the series pipeline reactor, reduces the reaction holdup while ensuring the yield of the product, fundamentally solves the problems caused by batch kettle reaction, and sets backflow external circulation between the cooler and the intensifying mixing device, accurately controls the reaction temperature by controlling the backflow amount, effectively avoids the decomposition of diazonium salt, and improves the yield of the product;

[0039] 2. The application accurately controls the reaction raw material ratio, accurately controls the reaction temperature through cooling and backflow, so as to control the reaction conditions, maintain the stability of the reaction process, and improve the safety of the reaction;

[0040] 3. The application adopts the production system and production process to reduce the amount of water and acid in traditional production, reduces the wastewater discharge by more than 10%, effectively controls the generation of wastewater, reduces the pollution of dye production to the environment, and realizes green chemical industry. BRIEF DESCRIPTION OF DRAWINGS

[0041] The above and / or additional aspects and advantages of the application will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:

[0042] Figure 1 is a structural schematic diagram of a continuous diazo coupling production system of disperse dyes.

[0043] 1-diazonium intensifying mixing device; 2-diazonium cooler; 3-diazonium pipeline reactor; 4-coupling intensifying mixing device; 5-coupling cooler; 6-coupling pipeline reactor; 7-first solid feeding bin; 8-first automatic feeder; 9-nitrosyl sulfuric acid feeding pipeline; 10-sulfuric acid feeding pipeline; 11-flow metering device; 12-second solid feeding bin; 13-second automatic feeder; 14-aromatic amine feeding pipeline; 15-water feeding pipeline; 16-cooling agent inlet; 17-cooling agent outlet; 18-diazonium liquid backflow outlet; 19-coupling liquid backflow outlet; 20-heat exchange medium inlet; 21-heat exchange medium outlet. DETAILED DESCRIPTION

[0044] In order to more clearly understand the above-mentioned purposes, features and advantages of the application, the application will be further described in detail below in combination with the drawings and specific embodiments. It should be noted that the technical solutions and features in the technical solutions of the present application can be combined with each other without conflict. Figure 1

[0045] ​In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present application, however, the present application can be practiced in other manners different from those described herein, and therefore, the scope of protection of the present application is not limited by the specific technical solutions disclosed below.

[0046] The technical solutions of the present application will be described below in combination with specific embodiments, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those skilled in the art without creative labor based on the present application are within the scope of protection of the present application.

[0047] The reaction of aromatic primary amine with nitrous acid to generate diazonium salt is called diazotization reaction, in which the diazonium component is aromatic primary amine, and the diazotization reagent is nitrous acid, nitrosyl sulfuric acid. The reaction of diazonium salt generated by the reaction with aromatic amine, phenol is called coupling reaction, which is often used to synthesize azo dyes or pigments containing azo groups in the molecule.

[0048] The technical solutions of the present application provide a continuous diazotization and coupling production system of disperse dyes, which comprises a diazotization reaction unit and a coupling reaction unit, and the diazotization reaction unit comprises:

[0049] A diazonium feeding unit is used for storing and conveying aromatic amine, nitrosyl sulfuric acid and sulfuric acid.

[0050] The diazonium feeding unit comprises:

[0051] A first solid feeding bin 7 is provided with a weighing device inside, which is used for storing and quantitatively feeding aromatic amine.

[0052] A first automatic feeder 8 is connected with the outlet of the first fixed feeding bin 7, and the outlet of the first automatic feeder 8 is connected with the inlet of the diazonium reinforced mixing device 1 through a conveying pipeline, which is used for conveying the aromatic amine quantitatively weighed by the first solid feeding bin 7.

[0053] A nitrosyl sulfuric acid feeding pipeline 9 is connected with the inlet of the diazonium reinforced mixing device 1, which is used for receiving nitrosyl sulfuric acid liquid and conveying it into the diazonium reinforced mixing device 1.

[0054] A sulfuric acid feeding pipeline 10 is connected with the inlet of the diazonium reinforced mixing device 1, which is used for receiving sulfuric acid liquid and conveying it into the diazonium reinforced mixing device 1.

[0055] Flow metering devices 11 are arranged on the nitrosyl sulfuric acid feeding pipeline 9 and the sulfuric acid feeding pipeline 10.

[0056] The diazotization reinforced mixing device 1 is connected with the outlet of the diazotization feeding unit, and is used for reinforcing mixing of the aromatic amine, nitrosyl sulfuric acid and sulfuric acid, fully mixing, improving the reaction rate, and then improving the production efficiency of industrial production.

[0057] The diazotization cooler 2 is connected with the outlet of the diazotization reinforced mixing device 1, and is used for reducing the temperature of the diazotization liquid.

[0058] The diazotization pipeline reactor 3 is connected with the outlet of the diazotization cooler 2, and is used for fully reacting the diazotization liquid.

[0059] The coupling reaction unit comprises:

[0060] The coupling feeding unit is used for storing and conveying the surfactant, the aromatic amine and water.

[0061] The coupling feeding unit comprises:

[0062] The second solid feeding bin 12 is provided with a weighing device, and is used for storing and quantitatively feeding the surfactant.

[0063] The second automatic feeder 13 is connected with the outlet of the second solid feeding bin 12, and the outlet of the second automatic feeder 13 is connected with the inlet of the coupling reinforced mixing device 4 through a conveying pipeline, and is used for conveying the quantitatively weighed surfactant in the second solid feeding bin 12.

[0064] The aromatic amine feeding pipeline 14 is connected with the inlet of the coupling reinforced mixing device 4, and is used for receiving the aromatic amine liquid and conveying the aromatic amine liquid into the coupling reinforced mixing device 4.

[0065] The water feeding pipeline 15 is connected with the inlet of the coupling reinforced mixing device 4, and is used for receiving the water and conveying the water into the coupling reinforced mixing device 4.

[0066] The flow metering device 11 is arranged on the aromatic amine feeding pipeline 14 and the water feeding pipeline 15.

[0067] The coupling reinforced mixing device 4 is connected with the outlet of the coupling feeding unit and the outlet of the diazotization pipeline reactor 3, and is used for reinforcing mixing of the diazotization liquid, the surfactant, the aromatic amine and the water, fully mixing, improving the reaction rate, and then improving the production efficiency of industrial production.

[0068] The coupling cooler 5 is connected with the outlet of the coupling reinforced mixing device 4, and is used for reducing the temperature of the coupling liquid.

[0069] The coupling pipeline reactor 6 is connected with the material outlet of the coupling cooler 5, and is used for full reaction of the coupling liquid.

[0070] Further, the first automatic feeder 8 and the second automatic feeder 13 are screw feeders, which are suitable for continuous metering and dosing, reliable operation, and high control precision.

[0071] Further, the diazo reinforcement mixing device 1 and the coupling reinforcement mixing device 4 are one of a dispersion pump or a homogenizing pump, so that multiple materials are rapidly mixed, and the reaction rate is improved.

[0072] Further, the diazo cooler 2 and the coupling cooler 5 are provided with a coolant inlet 16 and a coolant outlet 17, which are used for circulating a coolant, wherein the coolant is frozen brine; the diazo cooler 2 is further provided with a diazo liquid return outlet 18, which is connected with the inlet of the diazo reinforcement mixing device 1; the coupling cooler 5 is further provided with a coupling liquid return outlet 19, which is connected with the inlet of the coupling reinforcement mixing device 4; by arranging the return outlets, the return circulation is formed between the coolers and the reinforcement mixing devices, so that the return liquid and the initial materials are again reinforced in the reinforcement mixing devices; by controlling the return amount, the reaction temperature is accurately controlled, the decomposition of diazo salt is effectively avoided, and the yield of the product is improved.

[0073] Further, the diazo cooler 2 and the coupling cooler 5 are one of a tube type cooler, a plate type cooler or a winding pipe cooler.

[0074] Further, the diazo pipeline reactor 3 and the coupling pipeline reactor 6 are provided with a heat exchange medium inlet 20 and a heat exchange medium outlet 21, which are used for circulating a heat exchange medium, wherein the heat exchange medium is water vapor.

[0075] Further, the diazo pipeline reactor 3 and the coupling pipeline reactor 6 are one of a tube type reactor, a mixed pipeline reactor or a multi-stage kettle series reactor.

[0076] The second object of the present application is to provide a continuous diazo coupling production process of a disperse dye, which comprises:

[0077] Diazotization reaction: aromatic amine is added to the first solid feeding bin, weighed and then added to the diazotization intensification mixing device through the first automatic feeder. The addition amount of the aromatic amine is controlled in real time by the differential method. The feeding amount of sulfuric acid and nitrosyl sulfuric acid is adjusted by the flow metering device, which continuously and stably enters the diazotization intensification mixing device. The molar ratio of the aromatic amine, nitrosyl sulfuric acid and sulfuric acid is 1:(1-1.1):(0.5-6). The aromatic amine, nitrosyl sulfuric acid and sulfuric acid are fully mixed and reacted in the diazotization intensification mixing device to obtain diazotization liquid. The diazotization liquid is cooled in the diazotization cooler, and the cooling temperature is between 0 and 5 degrees Celsius. After cooling, part of the diazotization liquid is refluxed to the diazotization intensification mixing device, and the reflux ratio is controlled at 2-50. The remaining diazotization liquid is transported to the diazotization pipeline reactor for full reaction and then enters the coupling intensification mixing device.

[0078] Coupling reaction: the surfactant is added to the second solid feeding bin, weighed and then added to the coupling intensification mixing device through the second automatic feeder. The addition amount of the surfactant is controlled in real time by the differential method. The feeding amount of water and aromatic amine is adjusted by the flow metering device, which continuously and stably enters the coupling intensification mixing device. The molar ratio of water, aromatic amine and diazotization liquid is (100-1000):(0.92-1.02):1, wherein the diazotization liquid is calculated based on diazotization aromatic amine. The surfactant, water, aromatic amine and diazotization liquid are fully mixed and reacted in the coupling intensification mixing device to obtain coupling liquid. The coupling liquid is cooled in the coupling cooler, and the cooling temperature is between -3 and 5 degrees Celsius. After cooling, part of the coupling liquid is refluxed to the coupling intensification mixing device, and the reflux ratio is controlled at 1-5. The remaining coupling liquid is transported to the coupling pipeline reactor for full reaction and then subjected to crystallization treatment to obtain disperse dyes.

[0079] The surfactant is one or more of sulfamic acid, fast penetrating agent T, fatty alcohol polyoxyethylene ether, methyl naphthalene sulfonic acid formaldehyde condensate or lignin.

[0080] The disperse dye is an azo type disperse dye such as disperse orange, disperse blue, disperse yellow or disperse red.

[0081] When the aromatic amine for coupling is in solid form, it can be fed through the solid feeding bin.

[0082] In addition, when the solid raw materials for diazotization and coupling reactions are in the form of particles or tablets, they can be pre-pulped in the pulping and dissolving kettle and then metered and stably fed to the intensification mixing device for continuous reaction.

[0083] The following examples take the continuous production process of disperse dye R73 as an example:

[0084] Example 1

[0085] 98% sulfuric acid, nitrosyl sulfuric acid are continuously fed into diazotization disperser pump at a flow rate of 80 kg / h and 87 kg / h respectively, o-cyanophenyl nitro aniline is quantitatively fed into diazotization disperser pump by solid feeding station at a speed of 45 kg / h, the above raw materials are mixed and dispersed by diazotization disperser pump, the reaction is intensified, then the mixture is fed into diazotization cooler for cooling, the cooling medium is chilled brine, the diazotization liquid is cooled from 10 °C to 5 °C, then the diazotization liquid continuously refluxed in diazotization cooler is refluxed with the feed at a reflux ratio of 30 in part, the other part of the diazotization liquid is pumped into diazotization pipeline reactor for sufficient reaction, then the diazotization liquid is continuously fed into coupling disperser pump at a flow rate of 212 kg / h.

[0086] Water, N-ethyl-N-cyanoethyl aniline are continuously fed into coupling disperser pump at a flow rate of 2320 kg / h and 45 kg / h respectively, surfactant is quantitatively fed into coupling disperser pump by solid feeding station at a speed of 3 kg / h, the above raw materials are mixed and dispersed by coupling disperser pump, the reaction is intensified, then the mixture is fed into coupling cooler for cooling, the cooling medium is chilled brine. The coupling liquid is cooled from 8 °C to 3 °C, then the coupling liquid continuously refluxed in coupling cooler is refluxed with the feed at a reflux ratio of 3 in part, the other part of the coupling liquid is pumped into coupling pipeline reactor for sufficient reaction, the coupling reaction is completed after the product is recovered, the product yield is 97.2%, and the wastewater discharge is reduced by 12%.

[0087] Example 2

[0088] 98% sulfuric acid, nitrosyl sulfuric acid are continuously fed into diazotization disperser pump at a flow rate of 25 kg / h and 43 kg / h respectively, o-cyanophenyl nitro aniline is quantitatively fed into diazotization disperser pump by solid feeding station at a speed of 23 kg / h, the above raw materials are mixed and dispersed by diazotization disperser pump, the reaction is intensified, then the mixture is fed into diazotization cooler for cooling, the cooling medium is chilled brine, the diazotization liquid is cooled from 8 °C to 3 °C, then the diazotization liquid continuously refluxed in diazotization cooler is refluxed with the feed at a reflux ratio of 40 in part, the other part of the diazotization liquid is pumped into diazotization pipeline reactor for further aging reaction, then the diazotization liquid is continuously fed into coupling disperser pump at a flow rate of 91 kg / h.

[0089] Water, N-ethyl-N-cyanoethyl aniline are continuously fed into coupling disperser pump at a flow rate of 820 kg / h and 23 kg / h respectively, surfactant is quantitatively fed into coupling disperser pump by solid feeding station at a speed of 1.5 kg / h, the above raw materials are mixed and dispersed by coupling disperser pump, the reaction is intensified, then the mixture is fed into coupling cooler for cooling, the cooling medium is chilled brine, the coupling liquid is cooled from 10 °C to 5 °C, then the coupling liquid continuously refluxed in coupling cooler is refluxed with the feed at a reflux ratio of 8 in part, the other part of the coupling liquid is pumped into coupling pipeline reactor for further aging reaction, the coupling reaction is completed after the product is recovered, the product yield is 98.1%, and the wastewater discharge is reduced by 11%.

[0090] Example 3

[0091] 98% sulfuric acid is added into the beater at a constant rate of 120 kg / h, and o-cyanophenyl-nitroamine is added into the beater at a constant rate of 90 kg / h from the solid feeding station, the reflux ratio of the diazonium cooler is 25, and the diazonium liquid is continuously refluxed into the beater, the o-cyanophenyl-nitroamine is dissolved and mixed with the material in the beater, and then reacts with 180 kg / h nitrosyl sulfuric acid in the diazonium dispersion pump, the material is cooled in the diazonium cooler, the cooling medium is chilled brine, the diazonium liquid is cooled from 8°C to 3°C, and then a part of the diazonium liquid is refluxed according to the reflux ratio of 25, and the other part of the diazonium liquid is continuously fed into the diazonium pipeline reactor at a flow rate of 390 kg / h.

[0092] Water is continuously fed into the dissolving kettle at a rate of 500 kg / h, and the surfactant is added into the dissolving kettle at a rate of 5 kg / h from the solid feeding station, the surfactant is fully mixed and dissolved in the dissolving kettle, and then continuously fed into the coupling dispersion pump, water and N-ethyl-N-cyanethylphenylamine are continuously fed into the coupling dispersion pump at flow rates of 3000 kg / h and 90 kg / h respectively, the above raw materials are mixed and reacted in the coupling dispersion pump, and then cooled in the coupling cooler, the cooling medium is chilled brine, the coupling liquid is cooled from 8°C to 3°C, a part of the coupling liquid continuously refluxed in the coupling cooler is refluxed with the feed according to the reflux ratio of 15, and the other part of the coupling liquid is fed into the coupling pipeline reactor for further full reaction, and then the product is obtained after the crystallization transformation, the yield of the product is 96.8%, and the wastewater discharge is reduced by 14.5%.

[0093] The above is only a preferred embodiment of the present application, and is not used to limit the present application, and the present application can have various changes and variations for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A continuous diazo coupling production system for disperse dyes, comprising a diazo reaction unit and a coupling reaction unit, characterized in that: The diazo reaction unit includes: The diazo feed unit is used for storing and conveying aromatic amines, nitrosylsulfuric acid, and sulfuric acid; A diazo-enhanced mixing device, wherein the inlet of the diazo-enhanced mixing device is connected to the outlet of the diazo feed unit, and is used to enhance the mixing of aromatic amines, nitrosylsulfuric acid and sulfuric acid; A diazo cooler, wherein the material inlet of the diazo cooler is connected to the outlet of the diazo enhanced mixing device, is used to reduce the temperature of the diazo liquid; A diazo pipeline reactor, wherein the material inlet of the diazo pipeline reactor is connected to the material outlet of the diazo cooler, for the diazo liquid to undergo a full reaction; The coupling reaction unit includes: Coupling feed unit for storing and conveying surfactants, aromatic amines and water; A coupling-enhanced mixing device, wherein the inlet of the coupling-enhanced mixing device is connected to the outlet of the coupling feed unit and the material outlet of the diazo pipeline reactor, and is used to enhance the mixing of diazo liquid, surfactant, aromatic amine and water; A coupling cooler, wherein the material inlet of the coupling cooler is connected to the outlet of the coupling enhancement mixing device, is used to reduce the temperature of the coupling liquid; A coupling pipeline reactor, wherein the material inlet of the coupling pipeline reactor is connected to the material outlet of a coupling cooler, for the coupling liquid to undergo a full reaction; The diazo-enhanced mixing device and the coupling-enhanced mixing device are either dispersion pumps or homogenizing pumps. Both the diazo cooler and the coupling cooler are equipped with a coolant inlet and a coolant outlet for circulating coolant. The diazo cooler is also equipped with a diazo liquid reflux outlet, which is connected to the inlet of the diazo enhanced mixing device. The coupling cooler is also equipped with a coupling liquid reflux outlet, which is connected to the inlet of the coupling enhanced mixing device.

2. The continuous diazo coupling production system for disperse dyes according to claim 1, characterized in that: The diazo feed unit includes: The first solid feed bin is equipped with a weighing device for storing and quantitatively dispensing aromatic amines; The first automatic feeder has its inlet connected to the outlet of the first fixed feeding bin, and its outlet is connected to the inlet of the diazo-enhanced mixing device via a conveying pipe. It is used to convey the aromatic amines weighed quantitatively from the first solid feeding bin. A nitrosyl sulfuric acid feed pipe is connected to the inlet of the diazo-enhanced mixing device to receive liquid nitrosyl sulfuric acid and transport it to the diazo-enhanced mixing device. A sulfuric acid feed pipe is connected to the inlet of the diazo-enhanced mixing device and is used to receive liquid sulfuric acid and transport it to the diazo-enhanced mixing device. Both the nitrosyl sulfuric acid feed pipe and the sulfuric acid feed pipe are equipped with flow metering devices.

3. The continuous diazo coupling production system for disperse dyes according to claim 2, characterized in that: The coupling feeding unit includes: The second solid feed bin is equipped with a weighing device for storing and quantitatively dispensing surfactants. The second automatic feeder has its inlet connected to the outlet of the second fixed feeding bin, and its outlet connected to the inlet of the coupling-enhanced mixing device via a conveying pipe. It is used to convey the surfactant after quantitative weighing from the second solid feeding bin. An aromatic amine feed pipe is connected to the inlet of a coupling-enhancing mixing device to receive aromatic amine liquid and transport it to the coupling-enhancing mixing device. A water inlet pipe is connected to the inlet of the coupling-enhancing mixing device for receiving water and transporting it to the coupling-enhancing mixing device. Both the aromatic amine feed pipe and the water feed pipe are equipped with flow metering devices.

4. The continuous diazo coupling production system for disperse dyes according to claim 3, characterized in that: The first automatic feeder and the second automatic feeder are screw feeders.

5. The continuous diazo coupling production system for disperse dyes according to claim 1, characterized in that: The diazo cooler and coupling cooler are one of the following: tubular cooler, plate cooler, or spiral tube cooler.

6. The continuous diazo coupling production system for disperse dyes according to claim 1, characterized in that: Both the diazo pipeline reactor and the coupling pipeline reactor are equipped with a heat exchange medium inlet and a heat exchange medium outlet for circulating the heat exchange medium.

7. A continuous diazo coupling production system for disperse dyes according to claim 6, characterized in that: The diazo pipeline reactor and the coupling pipeline reactor are tubular reactors or pipeline reactors containing mixers.

8. A continuous diazo coupling production process for disperse dyes using the production system described in claim 3, characterized in that: include: Diazo reaction: Aromatic amine is added to the first solid feed hopper, weighed, and then fed into the diazo enhanced mixing device via the first automatic feeder. The addition amount of aromatic amine is controlled in real time using a differential method. Sulfuric acid and nitrosyl sulfuric acid are fed into the diazo enhanced mixing device continuously and stably by adjusting the feed rate through a flow metering device. The feed molar ratio of aromatic amine, nitrosyl sulfuric acid, and sulfuric acid is 1:(1-1.1):(0.5-6). Aromatic amine, nitrosyl sulfuric acid, and sulfuric acid are fully mixed and reacted in the diazo enhanced mixing device to obtain diazo liquid. The diazo liquid is cooled in a diazo cooler at a temperature between 0°C and 5°C. After cooling, part of the diazo liquid is returned to the diazo enhanced mixing device, with the return ratio controlled at 2-50. The remaining diazo liquid is transported to the diazo pipeline reactor for full reaction before entering the coupling enhanced mixing device. Coupling reaction: The surfactant is added to the second solid feed hopper, weighed, and then fed into the coupling-enhancing mixing device via the second automatic feeder. The amount of surfactant added is controlled in real time using a differential method. The feed rates of water and aromatic amine are adjusted by a flow metering device and continuously and stably enter the coupling-enhancing mixing device. The feed molar ratio of water, aromatic amine, and diazo solution is (100-1000):(0.92-1.02):1, where the diazo solution is calculated as diazo aromatic amine. The surfactant, water, aromatic amine, and diazo solution are fully mixed and reacted in the coupling-enhancing mixing device to obtain a coupling liquid. The coupling liquid is cooled in a coupling cooler at a temperature between -3°C and 5°C. After cooling, part of the coupling liquid is returned to the coupling-enhancing mixing device, with the return ratio controlled at 1-5. The remaining coupling liquid is transported to the coupling pipeline reactor for full reaction and then crystallization treatment to obtain disperse dye.

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