Heat setting system taking heat energy generated by reaction of printing and dyeing wastewater as heat source

Abstract

The invention provides a heat setting system taking heat energy generated by reaction of printing and dyeing wastewater as a heat source, and relates to the technical field of energy conservation and environmental protection. The system comprises a setting machine, a waste heat recovery and waste gas purification system, a wastewater concentration system and a supercritical water oxidation system, the setting machine is connected with a circulating water path, and the circulating water path is connected with the supercritical water oxidation system; the circulating water path is used for absorbing reaction heat generated in the reaction space and heat of reaction products through circulating water and conveying the circulating water absorbing the heat to the setting machine. Efficient treatment of printing and dyeing wastewater is achieved through supercritical water oxidation, meanwhile, waste liquid reaction heat and waste heat of reaction products serve as heat sources of the setting machine, and the advantages of being efficient and saving energy are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of energy saving and environmental protection, and in particular to a heat setting system using heat energy generated by reaction of printing and dyeing wastewater as heat source. BACKGROUND

[0002] Printing and dyeing is a technology that improves the dyeing quality, surface characteristics and appearance of textile products by adding various solvents and additives, thereby increasing the added value of textile products. Textile products after dyeing and rinsing need to be dried, stretched and heat treated by a heat setting machine to achieve the purpose of setting in combination with the thermoplastic characteristics of the fabric. The heat setting machine generally heats air by steam, and realizes the heat treatment of the fabric by hot air. According to statistics, the average steam consumption of the heat setting machine is about 1t / (h·table), and the energy consumption of the heat setting machine accounts for 70% of the total energy consumption of the printing and dyeing enterprise. The steam of the existing heat setting machine is often supplied by a coal-fired boiler or a natural gas direct-fired furnace, thereby consuming a large amount of fossil energy and possibly causing pollutant emissions.

[0003] In addition, the printing and dyeing process has many procedures, which will produce various wastewaters such as dyeing, printing, desizing and scouring, which contain various pollutants such as dyes, additives, acids and bases, fiber impurities, inorganic salts and heavy metals, and have characteristics such as high organic matter content, high colority, high alkalinity, high solid content and high oily component. Such wastewater not only has a huge output, but also is difficult to treat. At present, the printing and dyeing wastewater often uses a treatment method combining physical, chemical and biological methods, but the overall process flow is long, the treatment effect is poor, and the adaptability to the fluctuation of the wastewater is poor.

[0004] Therefore, the existing printing and dyeing industry mainly has the following technical defects:

[0005] 1. The energy consumption of the heat setting machine is high, and steam is often used as heat source, thereby consuming a large amount of fossil energy, but the steam condensation process not only easily causes problems of drain discharge and waste of waste heat, but also easily causes problems of high energy consumption and uneven preheating of fresh air due to uneven evaporation of scale and steam heat transfer coefficient;

[0006] 2. The printing and dyeing enterprise has a large amount of wastewater treatment, and the wastewater is rich in difficult-to-degrade organic matters such as dyes and fibers, and the traditional treatment process is complicated and has low treatment efficiency. SUMMARY

[0007] The present application aims to overcome the defects of the prior art, and provides a heat setting system using heat energy generated by reaction of printing and dyeing wastewater as heat source to solve the problems in the prior art.

[0008] To solve the above problems, the present application provides a heat setting system using heat energy generated by reaction of printing and dyeing wastewater as heat source, which comprises:

[0009] A setting machine is used to heat wet materials for fabric setting by using the reaction heat and the waste heat of reaction products of supercritical water oxidation of printing and dyeing wastewater as heat sources; wherein, the setting machine is connected with a circulating water circuit;

[0010] A waste heat recovery and exhaust gas purification system is used to treat exhaust gas generated in the process of fabric setting to recover waste heat and purify exhaust gas;

[0011] A wastewater concentration system is used to evaporate and concentrate initial wastewater generated in the production process to form concentrated liquid; wherein, the wastewater concentration system is connected with a homogenizing preheater;

[0012] A supercritical water oxidation system is used to separate the concentrated liquid into slurry and homogenized liquid by sending the concentrated liquid into a membrane separator; and preheat the homogenized liquid by sending the homogenized liquid into a homogenized liquid preheater; and send oxygen, the slurry and the preheated homogenized liquid into the reaction space of a cold wall reactor to react and obtain reaction products; the reaction products are sent into the homogenized liquid preheater to preheat the homogenized liquid; and the cooled reaction products are sent into a high pressure separator after decompression to obtain gas phase products; and the gas phase products are sent into the homogenized preheater to homogenize and preheat the concentrated liquid; and the liquid fluid discharged from the high pressure separator is sent into the wastewater concentration system to make the concentrated liquid;

[0013] The circulating water circuit is connected with the supercritical water oxidation system; the circulating water circuit is used to absorb the reaction heat and the heat of reaction products generated in the reaction space by circulating water, and the circulating water absorbing heat is transported to the setting machine.

[0014] In a possible implementation, the supercritical water oxidation system includes the cold wall reactor and a reaction product waste heat recovery branch, wherein the reaction product waste heat recovery branch is used to recover the waste heat of the reaction products;

[0015] The cold wall reactor includes a circulating water flow-through space, which is not connected with the reaction space and is arranged around the reaction space; wherein, a first branch of the circulating water circuit is connected with the circulating water flow-through space, and the water flowing through the circulating water flow-through space in the first branch is used to absorb heat in the reaction space;

[0016] The reaction product waste heat recovery branch comprises a temperature regulator for cooling the reaction product to a preset temperature; wherein the temperature regulator comprises a first channel and a second channel which are not connected to each other; the first channel is connected to the homogeneous liquid preheater for the reaction product to pass through; the second channel is connected to a second branch of the circulating water circuit, and the water flowing through the second channel in the second branch is used to absorb the heat emitted by the first channel.

[0017] In a possible implementation, the cold-wall reactor comprises an inner shell and a pressure-bearing outer shell, the inner shell is located inside the pressure-bearing outer shell, and the inner shell is spaced apart from the pressure-bearing outer shell; the reaction space is located inside the inner shell, and the circulating water flow passage is located between the inner shell and the pressure-bearing outer shell, wherein the circulating water flow passage is arranged around the inner shell;

[0018] The cold-wall reactor comprises a first end cover and a second end cover which are separately arranged at two ends in the height direction of the cold-wall reactor, and the inner shell and the pressure-bearing outer shell are located between the first end cover and the second end cover;

[0019] The first end cover is provided with a reaction product outlet and a circulating water inlet, wherein the reaction product outlet is connected to the reaction space, and the circulating water inlet is connected to the circulating water flow passage;

[0020] The second end cover is provided with a homogeneous liquid inlet, an oxygen inlet, a slurry inlet and a circulating water outlet, wherein the homogeneous liquid inlet, the oxygen inlet and the slurry inlet are connected to the reaction space, and the circulating water outlet is connected to the circulating water flow passage.

[0021] In a possible implementation, the setting machine comprises a fresh air inlet, an exhaust gas outlet, an air heater, an air heater heat source inlet, an air heater heat source outlet and an oven body; a distributor is arranged below the fresh air inlet, and the air heater is arranged below the distributor;

[0022] The fresh air inlet is used for air to enter; the distributor is used for the air entering from the fresh air inlet to flow to the air heater; the air heater is used for heating the air flowing out of the distributor; the oven body is used for spraying the air heated by the air heater to wet materials through nozzles to set the fabric; and the exhaust gas outlet is used for exhaust gas generated in the fabric setting process to be discharged.

[0023] The flow path of the water in the first branch sequentially passes through the air heater heat source outlet, the circulating water inlet, the circulating water outlet and the air heater heat source inlet; and the flow path of the water in the second branch sequentially passes through the air heater heat source outlet, the second channel and the air heater heat source inlet.

[0024] In a possible implementation, the waste heat recovery and exhaust gas purification system comprises an air blower, an exhaust gas heat recovery device and a spray tower, wherein the exhaust gas heat recovery device comprises an air pipeline and an exhaust gas pipeline which are not connected to each other;

[0025] The air blower is configured to send air into the air pipeline; one end of the air pipeline is connected to the air blower, and the other end is connected to the fresh air inlet; one end of the exhaust gas pipeline is connected to the exhaust gas outlet, and the other end is connected to the spray tower; the spray tower is configured to preliminarily purify exhaust gas through water washing; a liquid outlet of the spray tower is connected to a waste liquid storage tank, and an exhaust gas outlet of the spray tower is connected to a waste gas deep purification device.

[0026] In a possible implementation, the reaction product waste heat recovery branch comprises, in sequence, the homogeneous liquid preheater, the temperature regulator, a pressure reducing valve and the high-pressure separator; wherein the temperature regulator is connected to the homogeneous liquid preheater through the first channel, and the high-pressure separator is connected to the homogeneous preheater.

[0027] In a possible implementation, the supercritical water oxidation system comprises an oxygen branch, which is configured to deliver the oxygen to the reaction space;

[0028] The oxygen branch comprises an oxygen booster pump connected to the oxygen inlet.

[0029] In a possible implementation, the waste water concentration system comprises a waste liquid storage tank, a delivery pump and an evaporator;

[0030] The waste liquid storage tank is configured to store the initial waste liquid, and the delivery pump is configured to deliver the initial waste liquid from the waste liquid storage tank to the evaporator; wherein the initial waste liquid is evaporated and concentrated in the evaporator through negative pressure and heating, and the concentrated liquid is obtained;

[0031] The evaporator is connected to a condenser.

[0032] In a possible implementation, the evaporator is connected, in sequence, to a back pressure valve and a gas-liquid separator; the evaporator is further connected to the homogeneous preheater, wherein a concentrated liquid booster pump is arranged between the evaporator and the homogeneous preheater, and the concentrated liquid booster pump is configured to send the concentrated liquid in the evaporator to the homogeneous preheater;

[0033] The homogeneous preheater is connected to the membrane separator.

[0034] In a possible implementation, the homogeneous liquid preheater comprises a third channel and a fourth channel which are not in communication with each other, wherein the third channel is used for passing the homogeneous liquid, and the fourth channel is used for passing the reaction product.

[0035] The beneficial effects of the present application at least include:

[0036] 1. The reaction heat and waste heat of the reaction product of supercritical water oxidation of printing and dyeing wastewater are used as heat sources to replace fossil fuels, greatly reducing energy consumption and carbon emissions; in addition, the liquid heat source is easy to adjust, and the energy utilization efficiency of the heat source can be improved, making the temperature of the heat setting process more uniform;

[0037] 2. The printing and dyeing wastewater and the sizing machine exhaust water washing wastewater are mixed as the initial waste liquid, which is first concentrated by evaporation to form a large amount of steam condensate and a small amount of concentrated liquid, wherein the large amount of condensate has low concentration and volatile organic matter which is easy to be biodegraded, greatly reducing the treatment difficulty and allowing direct use of biochemical process;

[0038] 3. The treatment amount of the waste liquid is greatly reduced after concentration, and the pollutants are enriched, the organic concentration is greatly improved, thereby significantly reducing the waste liquid treatment amount, which is conducive to forming a hot liquid flame and reducing the energy consumption of supercritical water oxidation, thereby improving the treatment efficiency;

[0039] 4. The concentrated liquid is subjected to homogeneous dissolution and preliminary preheating of the supercritical water oxidation product (supercritical carbon dioxide) to form a homogeneous liquid and a slurry, the slurry avoids preheating causing pipeline deposition and blockage, and the homogeneous liquid is further preheated and oxidized to form a hot liquid flame, thereby rapidly preheating the concentrated slurry and intensifying its efficient removal. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0041] Figure 1 A heat setting system using the heat energy generated by the reaction of printing and dyeing wastewater as a heat source is shown;

[0042] Figure 2 A schematic diagram of a cold wall reactor is shown;

[0043] Figure 3 A schematic diagram of a sizing machine is shown;

[0044] Figure 4 The solubility of oxidized carbon at different pressures and temperatures and the homogeneous preheating process of the concentrated liquid are shown.

[0045] Explanation of main component symbols:

[0046] 1 - setting machine; 1-1: fresh air inlet; 1-2: exhaust gas outlet; 1-3: shell; 1-4: oven body; 1-5: air heater; 1-5a: air heater heat source outlet; 1-5b: air heater heat source inlet; 1-6: distributor; 2 - induced draft fan; 3 - exhaust gas heat recovery device; 4 - second temperature sensor; 5 - air supply fan; 6 - pressure reducing valve; 7 - spray tower; 8 - deep purification device; 9 - high pressure separator; 10 - waste liquid storage tank; 11 - condenser; 12 - delivery pump; 13 - gas-liquid separator; 14 - back pressure valve; 15 - evaporator; 16 - second one-way valve; 17 - concentrated liquid booster pump; 18 - first one-way valve; 19 - homogeneous preheater; 20 - membrane separator; 21 - slurry booster pump; 22 - homogeneous liquid booster pump; 23 - thermostat; 24 - homogeneous liquid preheater; 25 - oxygen booster pump; 26 - oxygen tank; 27 - cold wall reactor; 27-1: circulating water inlet; 27-2: reaction product outlet; 27-3: first end cover; 27-4: pressure-bearing shell; 27-5: inner shell; 27-6: second end cover; 27-7: homogeneous liquid inlet; 27-8: oxygen inlet; 27-9: slurry inlet; 27-10: circulating water outlet; 28 - flow valve; 29 - first temperature sensor; 30 - circulating pump. DETAILED DESCRIPTION

[0047] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the technical solutions of the present application will be described in detail below with reference to the drawings and specific embodiments. It should be pointed out that the described embodiments are only part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0048] Supercritical water oxidation is a technology for treating organic wastewater. Supercritical water oxidation is a method of "burning" oxidation of organic matter under high temperature and high pressure conditions exceeding the critical point (Pc = 22.1 MPa, Tc = 374℃) of water, with air or other oxidizing agents. The polarity of water is a function of temperature and pressure, and supercritical water is a non-polar solvent. In the environment of supercritical water, organic matter and gas can be completely miscible, the phase interface of gas-liquid two phases disappears, forming a homogeneous phase system, and the reaction speed is greatly accelerated. In less than 1 minute or even a few seconds of residence time, more than 99.9% of the organic matter is rapidly burned and oxidized into CO2, H2O and other non-toxic and harmless end products. Therefore, through supercritical water oxidation, high-efficiency degradation of printing and dyeing wastewater can be achieved. In addition, the large amount of heat energy released in the supercritical water oxidation process can be recovered as the heating heat source of the setting machine, thereby realizing the replacement of fossil fuels.

[0049] Embodiment

[0050] Reference Figures 1-4 In the embodiment, a heat setting system using heat energy generated by reaction of printing and dyeing wastewater as heat source is provided, comprising:

[0051] A setting machine 1 is used to heat wet materials to set fabrics using reaction heat and waste heat of reaction products of supercritical water oxidation degradation of printing and dyeing wastewater; wherein the setting machine 1 is connected with a circulating water circuit;

[0052] A waste heat recovery and exhaust gas purification system is used to treat exhaust gas generated in the process of fabric setting to recover waste heat and purify exhaust gas;

[0053] A wastewater concentration system is used to use wastewater generated in the production process as initial wastewater, evaporate and concentrate the initial wastewater to form concentrated liquid; wherein the wastewater concentration system is connected with a homogenizing preheater 19;

[0054] A supercritical water oxidation system is used to send the concentrated liquid to a membrane separator 20 for separation to obtain slurry and homogenized liquid; and send the homogenized liquid to a homogenized liquid preheater 24 for preheating; and send oxygen, slurry and preheated homogenized liquid to the reaction space of a cold wall reactor 27 for reaction to obtain reaction products; the reaction products are sent to the homogenized liquid preheater 24 to preheat the homogenized liquid; and the cooled reaction products are sent to a high pressure separator 9 after decompression to obtain gas phase products; and the gas phase products are sent to the homogenizing preheater 19 to homogenize and preheat the concentrated liquid; and the liquid fluid discharged from the high pressure separator 9 is sent to the wastewater concentration system to make concentrated liquid;

[0055] The circulating water circuit is connected with the supercritical water oxidation system; the circulating water circuit is used to absorb reaction heat and heat of reaction products generated in the reaction space by circulating water, and the circulating water absorbing heat is transported to the setting machine 1.

[0056] In the embodiment, the supercritical water oxidation system comprises the cold wall reactor 27 and a reaction product waste heat recovery branch, wherein the reaction product waste heat recovery branch is used to recover waste heat of the reaction products.

[0057] The cold wall reactor 27 comprises a circulating water flow-through space, the circulating water flow-through space is not communicated with the reaction space, and the circulating water flow-through space is arranged around the reaction space. The first branch of the circulating water circuit is connected with the circulating water flow-through space, and the water liquid flowing through the circulating water flow-through space in the first branch is used to absorb heat in the reaction space.

[0058] The reaction product waste heat recovery branch comprises a temperature regulator 23, the temperature regulator 23 is used to cool the reaction products to a preset temperature.

[0059] The temperature regulator 23 comprises a first channel and a second channel which are not communicated with each other. The first channel is connected with the homogeneous liquid preheater 24 for the reaction product to pass through; the second channel is connected with the second branch of the circulating water circuit, and the water in the second branch passing through the second channel is used to absorb the heat emitted by the first channel.

[0060] As shown in Figure 2 The cold-wall reactor 27 comprises an inner shell 27-5 and a pressure-bearing outer shell 27-4. The inner shell 27-5 can be made of thinner material to reduce the manufacturing cost; the pressure-bearing outer shell 27-4 has the function of bearing pressure and can protect the inner shell 27-5.

[0061] The inner shell 27-5 is located inside the pressure-bearing outer shell 27-4, and the inner shell 27-5 is spaced apart from the pressure-bearing outer shell 27-4. The inner shell 27-5 and the pressure-bearing outer shell 27-4 can be coaxially arranged, and both of them can be arranged in the shape of a cylinder.

[0062] The reaction space is located inside the inner shell 27-5, and the circulating water flow space is located between the inner shell 27-5 and the pressure-bearing outer shell 27-4. The circulating water flow space is arranged around the inner shell 27-5.

[0063] The cold-wall reactor 27 comprises a first end cover 27-3 and a second end cover 27-6 which are separately arranged at both ends in the height direction of the cold-wall reactor 27, and the inner shell 27-5 and the pressure-bearing outer shell 27-4 are located between the first end cover 27-3 and the second end cover 27-6.

[0064] The first end cover 27-3 is provided with a reaction product outlet 27-2 and a circulating water inlet 27-1. The reaction product outlet 27-2 is communicated with the reaction space, and the circulating water inlet 27-1 is communicated with the circulating water flow space.

[0065] The second end cover 27-6 is provided with a homogeneous liquid inlet 27-7, an oxygen inlet 27-8, a slurry inlet 27-9 and a circulating water outlet 27-10. The homogeneous liquid inlet 27-7, the oxygen inlet 27-8 and the slurry inlet 27-9 are communicated with the reaction space, and the circulating water outlet 27-10 is communicated with the circulating water flow space.

[0066] The supercritical water oxidation system comprises an oxygen branch which is used to deliver oxygen to the reaction space. The oxygen branch comprises an oxygen booster pump 25 which is connected with the oxygen inlet 27-8.

[0067] The oxygen in the oxygen tank 26 is pressurized to more than 23 MPa by the oxygen booster pump 25 and is injected from the oxygen inlet 27-8 of the cold-wall reactor 27 to successively have supercritical water oxidation reaction with the homogeneous liquid and the slurry.

[0068] As shown in Figure 3As shown, the setting machine 1 includes a shell 1-3, a fresh air inlet 1-1, a waste gas outlet 1-2, an air heater 1-5, an air heater heat source inlet 1-5b, an air heater heat source outlet 1-5a, and an oven body 1-4. A distributor 1-6 is arranged below the fresh air inlet 1-1, and the air heater 1-5 is arranged below the distributor 1-6.

[0069] The fresh air inlet 1-1 is configured to allow air to enter; the distributor 1-6 is configured to allow the air entering from the fresh air inlet 1-1 to flow to the air heater 1-5; the air heater 1-5 is configured to heat the air flowing out of the distributor 1-6; the oven body 1-4 is configured to spray the air heated by the air heater 1-5 to the wet material through the nozzle to set the fabric; and the waste gas outlet 1-2 is configured to allow the waste gas generated in the fabric setting process to be discharged.

[0070] In the heat setting process of the setting machine 1, fresh air enters from the fresh air inlet 1-1, flows to the oven body 1-4 after absorbing heat from the air heater 1-5 through the distributor 1-6, and is sprayed to the wet cloth through the nozzle of the oven body 1-4, thereby completing the heat setting of the fabric. The temperature of the heated air is 180-230℃, and the sizing agent, the auxiliary agent, and the oil agent on the fabric will volatilize or peel off under the action of high temperature, thereby generating waste gas which is discharged from the waste gas outlet 1-2. The waste gas contains various characteristic pollutants such as particulate matter, VOCs, formaldehyde, benzene, oil fume, and odor.

[0071] In this embodiment, the flow path of the water liquid in the first branch is in sequence through the air heater heat source outlet 1-5a, the circulating water inlet 27-1, the circulating water outlet 27-10, the air heater heat source inlet 1-5b, and the air heater heat source outlet 1-5a, and thereby realizes circulation; and the flow path of the water liquid in the second branch is in sequence through the air heater heat source outlet 1-5a, the second channel, the air heater heat source inlet 1-5b, and the air heater heat source outlet 1-5a, and thereby realizes circulation.

[0072] The waste gas generated by the setting machine 1 is recovered and purified by the waste heat recovery and waste gas purification system.

[0073] The waste heat recovery and waste gas purification system includes a supply fan 5, a waste gas heat recovery device 3, and a spray tower 7, wherein the waste gas heat recovery device 3 includes an air pipeline and a waste gas pipeline which are not in communication with each other.

[0074] The air blower 5 is used for sending air into the air pipeline; one end of the air pipeline is connected with the air blower 5, and the other end is connected with the fresh air inlet 1-1; one end of the exhaust gas pipeline is connected with the exhaust gas outlet 1-2, and the other end is connected with the spray tower 7; the spray tower 7 is used for preliminary purification of the exhaust gas through water washing; the liquid outlet of the spray tower 7 is connected with the waste liquid storage tank 10, and the gas outlet of the spray tower 7 is connected with the exhaust gas deep purification device 8. The exhaust gas deep purification device 8 includes a plasma purifier and the like.

[0075] The fresh air sucked by the air blower 5 enters the exhaust gas heat recovery device 3 and is preheated to 100-150℃, and then enters the setting machine 1 from the fresh air inlet 1-1, and then the setting of the woven fabric is completed. The generated exhaust gas is discharged from the exhaust gas outlet 1-2, introduced into the exhaust gas heat recovery device 3 by the induced draft fan 2 to preheat the fresh air. The cooled exhaust gas enters the spray tower 7, is preliminarily purified by water washing, the generated spray waste liquid enters the waste liquid storage tank 10, and then the exhaust gas is purified by the exhaust gas deep purification device 8 to reach the emission standard. Most of the pollutants in the exhaust gas of the setting machine 1 are dissolved and condensed in the spray waste liquid.

[0076] The reaction product waste heat recovery branch includes a homogeneous liquid preheater 24, a temperature regulator 23, a pressure reducing valve 6 and a high-pressure separator 9 connected in sequence. The temperature regulator 23 is connected with the homogeneous liquid preheater 24 through a first channel, and the high-pressure separator 9 is connected with the homogeneous preheater 19.

[0077] Specifically, the circulating water discharged from the air heater heat source outlet 1-5a and cooled is slightly pressurized by the circulating pump 30 and then divided into two branches: one part enters the cold wall reactor 27 through the circulating water inlet 27-1, absorbs the heat of the supercritical water oxidation reaction in the circulating water flow space, and then flows out from the circulating water outlet 27-10; the other part enters the temperature regulator 23 to absorb the heat of the reaction product. Then, the circulating water of the two branches is combined and enters the setting machine 1 from the air heater heat source inlet 1-5b to preheat the fresh air, and the temperature of the preheated air is 180-230℃.

[0078] A first temperature sensor 29 is arranged in front of the air heater heat source inlet 1-5b, which detects the temperature at this position and feeds back to the control module. The control module controls the circulating pump 30 according to the temperature signal detected by the first temperature sensor 29 to adjust the flow rate of the circulating water, so that the temperature of the circulating water entering the setting machine 1 is controlled at 300-360℃. In this way, the stability of the preheating temperature of the fresh air is ensured, and the overheating and salt deposition of the cold wall reactor 27 are avoided.

[0079] The control module includes a microprocessor or a single-chip microcomputer and the like.

[0080] The reaction product discharged from the product outlet of the cold wall reactor 27 has a temperature of 400-550℃ and mainly contains water, carbon dioxide, oxygen and inorganic salts. The reaction product is first introduced into the homogeneous liquid preheater 24 to preheat the homogeneous liquid, and then introduced into the temperature regulator 23 to reduce the temperature to 280-320℃. The reaction product is then introduced into the high pressure separator 9 after being depressurized by the pressure reducing valve 6.

[0081] A second temperature sensor 4 is arranged before the pressure reducing valve 6. The second temperature sensor 4 detects the temperature at this position and feeds back the temperature signal to the control module. The control module controls the flow valve 28 according to the temperature signal detected by the second temperature sensor 4, thereby adjusting the temperature before the high pressure separator 9. The pressure of the pressure reducing valve 6 is set to 6-18 MPa.

[0082] The gaseous phase product obtained by separation is discharged from the upper part of the high pressure separator 9, introduced into the homogeneous preheater 19 after passing through the second one-way valve 16, and mixed with the concentrated liquid, thereby achieving the homogeneous treatment and preliminary preheating of the concentrated liquid.

[0083] The fluid discharged from the high pressure separator 9 is introduced into the evaporator 15 as a heating heat source to heat the initial waste liquid, thereby achieving the concentration of the initial waste liquid. After being cooled, the fluid is reduced to normal temperature and pressure by the back pressure valve 14, and then introduced into the gas-liquid separator 13. After gas-liquid separation, the fluid is discharged.

[0084] The homogenization of the concentrated waste liquid is closely related to the solubility of carbon dioxide in high pressure water. The homogenization process of the concentrated liquid under typical conditions is introduced through experimental data. Figure 4 Point A is the node after the temperature regulator 23 and before the pressure reducing valve 6. The node is cooled to 300℃ by the temperature regulator 23. Since it is under high pressure, the solubility of carbon dioxide in high pressure water is still very high. Therefore, most of the carbon dioxide in the product at node A is dissolved in the high pressure water.

[0085] The reaction product pressure is reduced by the pressure reducing valve 6 to 10 MPa, and the carbon dioxide solubility is greatly reduced. After entering the high-pressure separator 9, most of the carbon dioxide is precipitated as a gas and discharged from the upper outlet of the high-pressure separator 9. Subsequently, the carbon dioxide enters the homogeneous preheater 19 and is mixed with the low-temperature concentrated solution, and the temperature of the carbon dioxide is rapidly reduced to achieve the preliminary preheating of the concentrated solution, and the pressure can be increased. At the same time, the temperature of the homogeneous preheater 19 is greatly lower than that of the high-pressure separator 9, that is, the carbon dioxide enters the C point state. In this state, the carbon dioxide is in its supercritical state (critical point is 7.38 MPa, 31.1°C), and the supercritical carbon dioxide has a dissolving and extracting effect on organic matter, so that most of the liquid-phase organic matter and part of the solid-phase organic matter in the concentrated solution are dissolved in the carbon dioxide. In addition, under this temperature condition, the solubility of carbon dioxide in high-pressure water is also rapidly increased; if the pressure is increased, the solubility of carbon dioxide can be further increased. Therefore, the carbon dioxide and its dissolved substances can be uniformly distributed in the high-pressure water, and then enter the membrane separator 20, that is, the homogeneous liquid and the slurry formed by the remaining part of the insoluble particulate matter can be separated.

[0086] In the embodiment, the wastewater concentration system comprises a waste liquid storage tank 10, a delivery pump 12 and an evaporator 15. The waste liquid storage tank 10 is used to store the initial waste liquid, and the delivery pump 12 is used to deliver the initial waste liquid from the waste liquid storage tank 10 to the evaporator 15. The initial waste liquid is evaporated and concentrated in the evaporator 15 by negative pressure and heating, and the concentrated liquid is obtained.

[0087] The evaporator 15 is connected with the condenser 11.

[0088] The printing and dyeing wastewater and the water washing wastewater of the setting machine 1 enter the waste liquid storage tank 10 to form the initial waste liquid. The initial waste liquid is rich in dyes, pulp, auxiliaries, fiber impurities, sand-like substances, inorganic salts and other pollutants; the initial waste liquid is a typical high-organic, refractory, high-oily component, high-salt, high-solid wastewater, and the treatment capacity is huge. The organic matter concentration of the initial waste liquid is generally 3000-30000 mg / L. The mixed wastewater enters the evaporator 15 from the upper inlet of the evaporator 15 under the action of the negative pressure and the heating of the heat source, is evaporated and concentrated, the evaporation process temperature is controlled at 60-80°C, and the concentration ratio is controlled at 2-8. The steam formed by the evaporation of the wastewater is discharged from the upper outlet of the evaporator 15, and part of the organic matter in the wastewater volatilizes into the condenser 11 to form low-concentration wastewater, which can be subsequently introduced into a biochemical system for direct treatment. The refractory, oily, particulate and other refractory organic matter and inorganic salts enter the concentrated liquid and are discharged from the lower outlet of the evaporator 15. The inorganic salt concentration of the concentrated liquid is less than 1%.

[0089] In the embodiment, the evaporator 15 is connected with the back pressure valve 14 and the gas-liquid separator 13 in sequence. The evaporator 15 is also connected with the homogenizing preheater 19, and a concentrated liquid booster pump 17 is arranged between the evaporator 15 and the homogenizing preheater 19, which is used to send the concentrated liquid in the evaporator 15 into the homogenizing preheater 19.

[0090] The homogenizing preheater 19 is connected with the membrane separator 20.

[0091] The concentrated liquid generated by the evaporator 15 is boosted to 6-18 MPa by the concentrated liquid booster pump 17, enters the homogenizing preheater 19 through the first one-way valve 1818, realizes the dissolution of most of the organic matters under the dissolution of the supercritical carbon dioxide, and realizes the partial preheating of the concentrated liquid. The preheated concentrated liquid enters the membrane separator 20, and then is separated to form the homogenized liquid and the slurry. The preheating temperature in the homogenizing preheater 19 is 150-250℃, and the pressure is 8-16 MPa.

[0092] The membrane separator 20 can adopt a microfiltration membrane for the interception of solid particles to form the slurry. Further, the microfiltration membrane can adopt inorganic materials such as ceramics and the like.

[0093] The homogenized liquid discharged from the membrane separator 20 is boosted to above 23 MPa by the homogenized liquid booster pump 22, and then enters the homogenized liquid preheater 24 and is preheated to 360-400℃, enters the homogenized liquid inlet 27-7 of the cold wall reactor 27, and reacts with the oxygen entering through the oxygen inlet 27-8 to form a hot liquid flame. At the same time, the slurry is boosted to above 23 MPa by the slurry booster pump 21, enters the slurry inlet 27-9 of the cold wall reactor 27, and realizes efficient treatment under the preheating and strengthening degradation of the hot liquid flame, and the reaction product is discharged from the reaction product outlet 27-2 of the cold wall reactor 27.

[0094] In the embodiment, the homogenized liquid preheater 24 includes a third channel and a fourth channel which are not communicated with each other, wherein the third channel is used for passing the homogenized liquid, and the fourth channel is used for passing the reaction product. The third channel and the fourth channel can realize heat exchange through air and the like, so that the heat of the reaction product can be transferred to the homogenized liquid.

[0095] The heat setting system provided in the application has at least the following advantages:

[0096] 1. The initial waste liquid is first evaporated and concentrated to form a concentrated liquid rich in refractory organic matter with higher concentration. On the one hand, the biochemical treatment difficulty of the condensed liquid is greatly reduced, and the treatment amount entering the supercritical water oxidation system is significantly reduced, which is beneficial to reduce the energy consumption and material consumption of the system. The concentrated liquid is rich in dissolved organic matter, oily organic matter, particulate organic matter and inorganic salt. Through the dissolution extraction of supercritical carbon dioxide, and then through membrane separation, homogeneous liquid and slurry are formed; the homogeneous liquid can be further preheated to facilitate the formation of hot liquid flame to achieve rapid degradation, and at the same time can be used as a heat source to rapidly preheat the concentrated slurry and strengthen its degradation, so as to realize the staged and synergistic treatment of the concentrated liquid.

[0097] 2. The supercritical water oxidation reaction is carried out in the cold wall reactor 27, wherein the circulating water in the circulating water flow space absorbs heat and also cools the inner shell 27-5 to avoid overheating and salt deposition of the reactor under the hot liquid flame reaction.

[0098] 3. The reaction heat of supercritical water oxidation is efficiently utilized through cascade recovery. The heat generated in the reaction process is absorbed by the circulating water and used as a heat source for the setting machine 1, and the temperature of the heat source is controlled in the subcritical temperature zone (liquid state) to avoid problems such as uneven air heating caused by steam condensation in the heat setting process, and condensate discharge. The heat of the reaction product is first used for preheating the homogeneous liquid, and then part of it is used for preheating the homogeneous liquid after temperature adjustment and pressure reduction, and the remaining heat is used for evaporation and concentration of the initial waste liquid.

[0099] 4. The heat energy generated in the reaction process of supercritical water oxidation degradation of printing and dyeing wastewater is used as a heat source to replace fossil fuels, greatly reducing energy consumption and carbon emissions. The liquid heat source is easy to adjust, and can improve the energy utilization efficiency of the heat source and realize uniform temperature in the heat setting process.

[0100] 5. The temperature of the heat source of the setting machine 1 is controlled by the temperature signal and the flow of the circulating pump 30, and the flow of the circulating water after temperature reduction is controlled by the temperature signal before the high-pressure separator 9, which realizes the temperature adjustment of the reaction product and controls the absorption of the reaction process heat of the cold wall reactor 27, so that the temperature of the homogeneous preheater 19 and the cold wall reactor 27 remains stable, which is beneficial to the dissolution and extraction of organic matter by supercritical carbon dioxide, and then the supercritical carbon dioxide and the organic matter are dissolved in the high-pressure water to form homogeneous liquid.

[0101] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are contained in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0102] Although the embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and are not to be construed as limiting the present application, and the person skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A heat setting system that uses the heat energy generated by the reaction of dyeing and printing wastewater as a heat source, characterized in that, include: A setting machine is used to heat wet materials for fabric setting by using the reaction heat of supercritical water oxidation degradation of dyeing and printing wastewater and the residual heat of the reaction products as a heat source; wherein, the setting machine is connected to a circulating water circuit. Waste heat recovery and exhaust gas purification system is used to treat the exhaust gas generated during the fabric setting process, so as to recover waste heat and purify exhaust gas. A wastewater concentration system is used to evaporate and concentrate the wastewater generated during the production process as initial waste liquid to form a concentrated liquid; wherein, the wastewater concentration system is connected to a homogenizing preheater; A supercritical water oxidation system is used to feed the concentrated liquid into a membrane separator for separation to obtain a slurry and a homogenized liquid; and to feed the homogenized liquid into a homogenized liquid preheater for preheating; and to feed oxygen, the slurry, and the preheated homogenized liquid into the reaction space of a cold-wall reactor for reaction to obtain reaction products; the reaction products are fed into the homogenized liquid preheater to preheat the homogenized liquid; and the cooled reaction products are fed into a high-pressure separator after depressurization to obtain gaseous products; and the gaseous products are fed into the homogenized preheater to homogenize and preheat the concentrated liquid; and the liquid fluid discharged from the high-pressure separator is fed into a wastewater concentration system for producing the concentrated liquid. The circulating water path is connected to the supercritical water oxidation system; the circulating water path is used to absorb the heat of reaction generated in the reaction space and the heat of the reaction products through circulating water, and to transport the heat-absorbing circulating water to the setting machine.

2. The heat setting system according to claim 1, which uses the heat energy generated by the reaction of dyeing and printing wastewater as a heat source, is characterized in that, The supercritical water oxidation system includes the cold-wall reactor and a waste heat recovery branch for the reaction products, wherein the waste heat recovery branch for the reaction products is used to recover the waste heat of the reaction products. The cold-wall reactor includes a circulating water flow space, which is not connected to the reaction space and is arranged around the reaction space; wherein, a first branch of the circulating water path is connected to the circulating water flow space, and the water flowing through the circulating water flow space in the first branch is used to absorb heat in the reaction space. The waste heat recovery branch of the reaction product includes a temperature controller, which is used to cool the reaction product to a preset temperature; wherein, the temperature controller includes a first channel and a second channel that are not interconnected; the first channel is connected to the homogenizing liquid preheater to allow the reaction product to pass through; the second channel is connected to a second branch of the circulating water circuit, and the water flowing through the second channel in the second branch is used to absorb the heat emitted by the first channel.

3. The heat setting system according to claim 2, which uses the heat energy generated by the reaction of dyeing and printing wastewater as a heat source, is characterized in that... The cold-wall reactor includes an inner shell and a pressure-bearing outer shell. The inner shell is located inside the pressure-bearing outer shell and is spaced apart from the pressure-bearing outer shell. The reaction space is located inside the inner shell, and the circulating water flow space is located between the inner shell and the pressure-bearing outer shell, wherein the circulating water flow space surrounds the inner shell. The cold-wall reactor includes a first end cap and a second end cap located at both ends in the height direction, and the inner shell and the pressure-bearing outer shell are located between the first end cap and the second end cap. The first end cap is provided with a reaction product outlet and a circulating water inlet, wherein the reaction product outlet is connected to the reaction space and the circulating water inlet is connected to the circulating water flow space; The second end cap is provided with a homogenizing liquid inlet, an oxygen inlet, a slurry inlet, and a circulating water outlet, wherein the homogenizing liquid inlet, the oxygen inlet, and the slurry inlet are connected to the reaction space, and the circulating water outlet is connected to the circulating water flow space.

4. The heat setting system according to claim 3, which uses the heat energy generated by the reaction of dyeing and printing wastewater as a heat source, is characterized in that... The setting machine includes a fresh air inlet, an exhaust gas outlet, an air heater, an air heater heat source inlet, an air heater heat source outlet, and an oven body; a distributor is provided below the fresh air inlet, and the air heater is provided below the distributor; The fresh air inlet is used to supply air; the distributor is used to direct the air entering from the fresh air inlet to the air heater; the air heater is used to heat the air flowing out from the distributor; the oven body is used to spray the air heated by the air heater onto the wet material through nozzles for fabric setting; and the exhaust outlet is used to discharge the exhaust gas generated during the fabric setting process. The water flow path in the first branch passes sequentially through the heat source outlet of the air heater, the inlet of the circulating water, the outlet of the circulating water, and the heat source inlet of the air heater; the water flow path in the second branch passes sequentially through the heat source outlet of the air heater, the second channel, and the heat source inlet of the air heater.

5. The heat setting system according to claim 4, which uses the heat energy generated by the reaction of dyeing and printing wastewater as a heat source, is characterized in that... The waste heat recovery and exhaust gas purification system includes a blower, an exhaust gas heat recovery unit, and a spray tower, wherein the exhaust gas heat recovery unit includes air ducts and exhaust gas ducts that are not interconnected. The blower is used to deliver air into the air duct; one end of the air duct is connected to the blower, and the other end is connected to the fresh air inlet; one end of the exhaust gas duct is connected to the exhaust gas outlet, and the other end is connected to the spray tower; the spray tower is used to perform preliminary purification of the exhaust gas by water washing; the drain outlet of the spray tower is connected to the waste liquid storage tank, and the exhaust outlet of the spray tower is connected to the deep purification device for exhaust gas.

6. The heat setting system according to claim 2, which uses the heat energy generated by the reaction of dyeing and printing wastewater as a heat source, is characterized in that, The waste heat recovery branch of the reaction product includes the homogenizing liquid preheater, the temperature controller, the pressure reducing valve and the high-pressure separator connected in sequence; wherein, the temperature controller is connected to the homogenizing liquid preheater through the first channel, and the high-pressure separator is connected to the homogenizing liquid preheater.

7. The heat setting system according to claim 2, which uses the heat energy generated by the reaction of dyeing and printing wastewater as a heat source, is characterized in that, The supercritical water oxidation system includes an oxygen branch, which is used to supply oxygen to the reaction space. The oxygen branch includes an oxygen booster pump, which is connected to the oxygen inlet.

8. The heat setting system according to claim 1, which uses the heat energy generated by the reaction of dyeing and printing wastewater as a heat source, is characterized in that... The wastewater concentration system includes a waste liquid storage tank, a transfer pump, and an evaporator; The waste liquid storage tank is used to store the initial waste liquid, and the transfer pump is used to transfer the initial waste liquid from the waste liquid storage tank to the evaporator; wherein, the initial waste liquid is evaporated and concentrated in the evaporator by negative pressure and heating to obtain the concentrated liquid; The evaporator is connected to the condenser.

9. The heat setting system according to claim 8, which uses the heat energy generated by the reaction of dyeing and printing wastewater as a heat source, is characterized in that... The evaporator is connected in sequence to a back pressure valve and a gas-liquid separator; the evaporator is also connected to the homogenizing preheater, wherein a concentrate booster pump is provided between the evaporator and the homogenizing preheater, the concentrate booster pump being used to send the concentrate in the evaporator into the homogenizing preheater. The homogenizer is connected to the membrane separator.

10. The heat setting system according to claim 1, which uses the heat energy generated by the reaction of dyeing and printing wastewater as a heat source, is characterized in that, The homogenizing liquid preheater includes a third channel and a fourth channel that are not interconnected, wherein the third channel is used for the homogenizing liquid to pass through, and the fourth channel is used for the reaction products to pass through.

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