VOCs treatment waste heat recovery system of printing and dyeing setting machine

Abstract

The utility model discloses a printing and dyeing setting machine VOCs (volatile organic compounds) treatment waste heat recovery system which comprises at least one air condensation exchanger device, a catalytic cracking burner, an activated carbon adsorption and desorption device, an oil-water separator and a printing and dyeing setting machine. A waste gas exhaust port of the air condensation exchanger device is communicated with a gas inlet of the catalytic cracking combustor, an exhaust port of the catalytic cracking combustor is communicated with a gas inlet of the activated carbon adsorption and desorption device, and an exhaust port of the activated carbon adsorption and desorption device is communicated with the outside through a waste gas exhaust pump. A cooling gas inlet of the air condensation exchanger device and a cooling gas inlet of the activated carbon adsorption and desorption device are communicated with the outside through a cold air pump, and a cooling gas outlet of the air condensation exchanger device and a cooling gas outlet of the activated carbon adsorption and desorption device are communicated with an air inlet of the printing and dyeing setting machine. According to the invention, redundant heat in the waste gas is recovered through the air condensation exchanger device, and meanwhile, the content of VOCs in the waste gas can be reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of waste gas treatment and recovery, and particularly relates to a VOCs treatment waste heat recovery system and method for a printing and dyeing setting machine. Background Art

[0002] The textile printing and dyeing industry generates significant waste gas emissions during its production process. Thermal exhaust from these machines is a major source of thermal pollution and VOCs. This exhaust contains significant amounts of water, oil vapor, grease, organic matter, solvents, fabric staples, and mechanical dust, occasionally causing explosions. This contamination corrodes equipment, clogs pipelines and valves, and significantly harms printing and dyeing operations. These complex issues create a complex challenge for managing these waste gases. Exhaust pollutants, waste heat, and VOCs harm the environment and undermine economic interests.

[0003] The printing and dyeing setting machine has a large amount of exhaust gas and heat, about 60,000M 3 / H, with an exhaust temperature of 180°C, resulting in significant waste. Efficient energy utilization and VOC emission control are real challenges. Wasted heat energy from setting machine exhaust, as well as clogged filters and pipes, are common issues that seriously impact printing and dyeing production. Heat recycling and VOC emissions from hot exhaust gases seriously pollute the air quality in textile manufacturing locations, and there is currently no effective, systematic solution. These are urgent, environmentally friendly, and economically challenging economic and technological innovations that require comprehensive solutions.

[0004] Secondly, heat recycling and energy conservation are key issues in today's economic innovation. Heat loss from stenter exhaust gases is primarily concentrated in the heat loss of the equipment's external casing, including heat loss in the hot air used to dry fabrics. These are the two major sources of heat energy loss, estimated to account for over 50%-80% of the total heat loss.

[0005] The use of simple, standard heat exchangers in textile printing and dyeing machines presents significant challenges due to the unique media conditions within these machines, which contain a variety of substances, including water, organic matter, oils, short fibers, mechanical particulate dust, and organic VOCs. The water vapor evaporated from drying cloth condenses significantly, containing large amounts of vaporized oil, organic matter, and solvents. This water vapor, along with the fine fiber dust from the cloth, rapidly adheres to the heat exchange tube walls, attracting and adhering to the exhaust gas particles. This increases the viscosity of the condensate, causing it to cling to the tube walls. The condensed water-oil mixture, in turn, attracts a significant amount of dust. The combined effects of the water, oil, and dust make the mixture even more difficult to flow. This repetitive cycle causes the tube walls to instantly form a fouling mixture of the three, rapidly reducing the heat transfer coefficient of the heat exchange tube walls and impairing the heat exchange quality between the hot and cold media. This gradually diminishes the heat transfer efficiency, causing the mixture to accumulate and impair heat exchange. Utility Model Content

[0006] In view of the defects or deficiencies in the above-mentioned prior art, the present invention aims to provide a VOCs treatment waste heat recovery system for a printing and dyeing setting machine. The purpose of this application is achieved through the following technical solutions:

[0007] A VOCs treatment waste heat recovery system for a printing and dyeing setting machine comprises at least one air condensation exchanger device, a catalytic cracking burner, an activated carbon adsorption desorber, an oil-water separator and a printing and dyeing setting machine, wherein the exhaust port of the printing and dyeing setting machine is connected to the exhaust gas inlet of the air condensation exchanger device, the exhaust gas exhaust port of the air condensation exchanger device is connected to the air inlet of the catalytic cracking burner, the exhaust port of the catalytic cracking burner is connected to the air inlet of the activated carbon adsorption desorber, the exhaust port of the activated carbon adsorption desorber is connected to the outside world through an exhaust gas discharge pump, the cooling air inlet of the air condensation exchanger device and the cooling air inlet of the activated carbon adsorption desorber are connected to the outside world through a cold air pump, and the cooling air outlet of the air condensation exchanger device and the cooling air outlet of the activated carbon adsorption desorber are connected to the air inlet of the printing and dyeing setting machine.

[0008] Preferably, the air condensation exchanger device includes a cylinder, a waste gas inlet is provided on the top of the cylinder, a waste gas exhaust port is provided on the bottom, an exchange space is formed in the middle of the cylinder by sealing with a head plate, a spray chamber connected to the waste gas inlet is provided in the upper part of the cylinder, a plurality of heat exchange tubes are installed in the exchange space, the two ends of the heat exchange tubes are respectively connected to the spray chamber and the waste gas exhaust port, a spray device is installed in the spray chamber, and an active agent coating is provided on the inner wall of the heat exchange tube; a cooling air inlet is provided at the lower part of the cylinder, a cooling air outlet is provided at the upper part of the cylinder, and the cooling air inlet and the cooling air outlet are connected to the exchange space.

[0009] Preferably, the exhaust gas outlet of the air condensation exchanger device is also connected to the liquid inlet of the oil-water separator, and the air inlet of the activated carbon adsorption desorber is connected to the liquid inlet of the oil-water separator; the oil-water separator is connected to the spray device of the air condensation exchanger device through a spray water pump.

[0010] Preferably, an electrostatic precipitator and a first pulse filter are provided between the exhaust port of the printing and dyeing setting machine and the exhaust gas inlet of the air condensation exchanger device, and the exhaust port of the activated carbon adsorption desorber is also connected to the air inlet of the printing and dyeing setting machine through the second pulse filter.

[0011] Preferably, the number of the air condensation exchanger devices is 4-10, and the cooling air outlets and cooling air inlets of two adjacent air condensation exchanger devices are connected via a pipeline.

[0012] Preferably, the spray device includes a self-rotating disc, a liquid flow pipe, a nozzle, a water inlet pipe and a fixed frame. The fixed frame is installed on the top of the spray chamber. Several liquid flow pipes are provided and installed at equal intervals on the circumference of the self-rotating disc. The lower part of the water inlet pipe is rotatably connected to the self-rotating disc and is connected to the liquid flow pipe through the self-rotating disc. The upper part of the water inlet pipe is connected to the fixed frame, and the nozzle is provided below the liquid flow pipe.

[0013] Preferably, the exhaust gas outlet of the air condensation exchanger device is connected to the liquid inlet of the oil-water separator through a first U-shaped tube, and the air inlet of the activated carbon adsorption desorber is connected to the liquid inlet of the oil-water separator through a second U-shaped tube.

[0014] A method for recovering waste heat from waste gas treatment of a printing and dyeing setting machine comprises the following steps:

[0015] Step 1: After the waste heat gas discharged from the printing and dyeing setting machine is filtered of dust, it enters from the top of the air condensation exchanger device and is dispersed into multiple heat exchange tubes in the spray chamber.

[0016] Step 2: The hot and cold fluids pass through the tube wall to exchange heat between the heat source exhaust fluid in the tube side and the cold source air fluid in the tube wall shell side. The cooled heat source exhaust fluid is discharged from the other end of the heat exchange tube and the air condensation exchanger system is used to recover the excess heat in the exhaust gas discharged under normal temperature conditions. The air condensation exchanger device recovers the excess heat in the exhaust gas and uses the normal temperature air temperature to condense and separate the VOCs in the exhaust gas.

[0017] Step 3: The exhaust gas enters the catalytic cracking burner, where it undergoes high-temperature catalytic cracking and incineration at 300-600°C to remove the remaining VOCs. The gas is then sent to the activated carbon adsorption desorber to absorb the remaining VOCs. Finally, it is discharged into the atmosphere, and a small amount of the treated gas is returned to the printing and dyeing setting machine for recycling.

[0018] Step 4: The spray device sprays the spray liquid into the heat exchange tube, stirring the adhered substances on the tube wall, and promptly washes away the mixed scale of oil, water, fiber and dust impurities adhered to the tube wall. The mixture is discharged into the oil-water separator through the exhaust port at the bottom, where the oil and water are separated and other impurities are precipitated. The separated water is recycled as the subsequent spray liquid;

[0019] Step 5: The cold air is sucked from the atmosphere by the cold air pump as the cold source air fluid and enters the air condensation exchanger device for heat exchange, and is discharged from the cooling air outlet as hot gas and enters the printing and dyeing setting machine;

[0020] Step 6: Cold air is sucked from the atmosphere through a cold air pump as cooling gas in the activated carbon adsorption desorber. After being heated, it becomes hot air and enters the printing and dyeing setting machine; a small amount of oil and water in the activated carbon adsorption desorber enters the oil-water separator for separation.

[0021] Compared with the prior art, this application has at least the following obvious advantages and effects:

[0022] 1. This utility model recovers excess heat from exhaust gas through an air condensation exchanger, achieving a recovery rate of 80%. Simultaneously, 95%-98% of the harmful VOCs in the exhaust gas, which are vaporized at room temperature, can be separated by condensation under normal temperature conditions. This minimizes the VOC content in the exhaust gas at room temperature, facilitating subsequent physical and chemical treatment and eliminating the common phenomenon of white smoke emanating from chimneys on top of printing and dyeing plant buildings. This recycling system significantly saves energy and achieves significant economic benefits.

[0023] 2. The utility model uses activated carbon adsorption, desorption, catalytic cracking and incineration technology to repeatedly process the exhaust gas with low VOC content after condensation. Through multiple activated carbon adsorption, desorption, catalytic cracking and incineration technology, the VOCs content in the exhaust gas of the shaping machine meets the emission standards and complies with national emission standards.

[0024] 3. The air condensation exchanger device in the present invention adopts pulse spraying, which can flush the oil stains and scale on the inner wall of the heat exchange tube, remove the oil impurities, and ensure the heat exchange effect of the air condensation exchanger device.

[0025] 4. The utility model separates the oil and water produced in the process through an oil-water separator, and the treated water can be recycled back to the system for use.

[0026] 5. The heat exchange tubes in the present invention are sprayed with a coating that is hydrophobic, oleophobic, anti-fouling, non-sticky, heat-conductive, non-fouling, and non-clogging, ensuring the normal instantaneous and efficient heat transfer effect of the tube wall and improving the absolute heat recovery rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0028] Figure 2 This is a schematic structural diagram of the air condensation exchanger device in the present utility model;

[0029] Figure 3 This is a schematic structural diagram of the spray device in the present utility model;

[0030] List of parts in this application:

[0031] 1. Air condensation exchanger; 2. Catalytic cracking burner; 3. Activated carbon adsorption desorber; 4. Oil-water separator; 5. Printing and dyeing setting machine; 6. Exhaust gas discharge pump; 7. Cold air pump; 8. Spray device; 9. Water outlet; 10. Oil outlet; 11. Spray water pump; 12. Electrostatic precipitator; 13. First pulse filter; 14. Second pulse filter; 15. First U-shaped tube; 16. Second U-shaped tube; 1 -1, cylinder; 1-2, exhaust gas inlet; 1-3, exhaust gas outlet; 1-4, head plate; 1-5, exchange space; 1-6, spray chamber; 1-7, heat exchange tube; 1-8, surfactant coating; 1-9, cooling air inlet; 1-10, cooling air inlet and outlet; 1-11, air intake control valve; 8-1, rotating disk; 8-2, liquid flow pipe; 8-3, nozzle; 8-4, water inlet pipe; 8-5, fixing bracket; DETAILED DESCRIPTION

[0032] Specific embodiments of the present application are described in conjunction with the accompanying drawings and the following description to teach those skilled in the art how to make and use the best mode of the present application. In order to teach the principles of the application, some conventional aspects have been simplified or omitted. Those skilled in the art should understand that variations from these embodiments fall within the scope of the present application. Those skilled in the art should understand that the following features can be combined in various ways to form multiple variations of the present application. Terms such as "upper", "lower", "left", "right", "middle" and "one" cited in this application are only for the convenience of description and are not intended to limit the scope of the implementation of the present invention. Changes or adjustments to their relative relationships should also be regarded as the scope of the implementation of the present invention without substantial changes in the technical content. Therefore, the present application is not limited to the specific embodiments described below, but is only limited by the claims and their equivalents.

[0033] Example 1

[0034] like Figure 1As shown, this embodiment relates to a VOCs treatment waste heat recovery system for a printing and dyeing setting machine, which includes at least one air condensation exchanger device 1, a catalytic cracking burner 2, an activated carbon adsorption desorber 3, an oil-water separator 4 and a printing and dyeing setting machine 5, the exhaust port of the printing and dyeing setting machine 5 is connected to the exhaust gas inlet of the air condensation exchanger device 1, the exhaust gas exhaust port of the air condensation exchanger device 1 is connected to the air inlet of the catalytic cracking burner 2, the exhaust port of the catalytic cracking burner 2 is connected to the air inlet of the activated carbon adsorption desorber 3, the exhaust port of the activated carbon adsorption desorber 3 is connected to the outside world through an exhaust gas discharge pump 6, the cooling air inlet of the air condensation exchanger device 1 and the cooling air inlet of the activated carbon adsorption desorber 3 are connected to the outside world through a cold air pump 7, the cooling air outlet of the air condensation exchanger device 1 and the cooling air outlet of the activated carbon adsorption desorber 3 are connected to the outside world through a cold air pump 7. The outlet is connected to the air inlet of the printing and dyeing setting machine 5. In this application, the high-temperature exhaust gas in the printing and dyeing setting machine 5 is heat-exchanged with the normal-temperature air through the air condensation exchanger device. The normal-temperature air after the heat exchange is heated and supplied to the printing and dyeing setting machine 5. Most of the VOCs harmful components in the exhaust gas are condensed and separated in the air condensation exchanger device 1. The remaining VOCs harmful components enter the subsequent catalytic cracking burner 2 for cracking and incineration and the activated carbon adsorption desorber 3 for treatment and absorption to meet the atmospheric emission standards. During the cracking and incineration in the catalytic cracking burner 2, the exhaust gas temperature rises again and is cooled in the activated carbon adsorption desorber 3 by the normal-temperature air and then discharged. At the same time, the normal-temperature air temperature rises and can be used by the printing and dyeing setting machine 5. This system can not only process high-temperature and high-VOCs exhaust gas, but also recycle the residual heat back to the printing and dyeing setting machine 5. This system can promote energy saving of thermal exhaust emissions by more than 50%-80%; each printing and dyeing setting machine can save about 300m3 of natural gas per day. 3 , saving 1,350 yuan / day / unit; generating annual economic benefits of 400,000 yuan / unit; each printing and dyeing setting machine reduces carbon emissions by 17,000 tons of carbon dioxide annually, with huge environmental benefits.

[0035] like Figure 2As shown, in the embodiment of the present application, the air condensation exchanger device 1 includes a cylinder 1-1, an exhaust gas inlet 1-2 is provided on the top of the cylinder 1-1, an exhaust gas outlet 1-3 is provided on the bottom, the middle of the cylinder 1-1 is sealed by a head plate 1-4 to form an exchange space 1-5, and a spray chamber 1-6 connected to the exhaust gas inlet is provided in the upper part of the cylinder 1-1. A plurality of heat exchange tubes 1-7 are installed in the exchange space 1-5, and the two ends of the heat exchange tube 1-7 are respectively connected to the spray chamber 1-6 and The exhaust gas outlet 1-3 is connected, a spray device 8 is installed in the spray chamber 1-6, and an active agent coating 1-8 is provided on the inner wall of the heat exchange tube 1-7; a cooling gas inlet 1-9 is provided at the lower part of the cylinder 1-1, and a cooling gas outlet 1-10 is provided at the upper part of the cylinder 1-1. The cooling gas inlet 1-9 and the cooling gas outlet 1-10 are connected to the exchange space 1-5, and the high-temperature exhaust gas passes through the heat exchange tube 1-7, and the normal temperature air flows through the exchange space 1-5, and the two complete heat exchange through the tube wall of the heat exchange tube 1-7.

[0036] Specifically, the active agent coatings 1-8 are organic fluorine surfactant coatings, using one or more of fluorocarbon, hydrocarbon, silicon nitrogen surfactants, and fluorinated polymers as the primary hydrophobic and oleophobic antifouling polymer adhesives to form a film-forming material. This reduces surface tension, ensuring a low surface tension coating state that meets the requirements for water droplet rolling, with a hydrophobic angle of >150°, an oleophobic angle of >140° for oil droplets, and a flow angle of >2° for both water and oil droplets. This creates a ceramic-like lotus-effect surface morphology with hydrophobic and oleophobic antifouling properties. The coating film is composed of organic surface tension-active polymers or inorganic materials, mixed metal micro-nanoparticles, and a water-soluble surface organic component. The inner wall of the thin condenser tube is automatically spray-coated with a thickness of 10-30 μm and a service life of 1-3 years or more. This provides excellent super-hydrophobic, super-oleophobic, antifouling, and efficient heat transfer properties for equipment, pipes, and valves. In particular, it prevents and reduces the risk of scaling, fouling, and charring on the inner walls of pipes and equipment, extending cleaning cycles. This thoroughly solves the problem of frequent cleaning and unblocking of condensing equipment pipes, ensuring that the equipment pipes remain clean, unobstructed, and have efficient heat transfer effects for a long time. A certain proportion of metal micropowder, ceramic micropowder, graphite micropowder, graphene micropowder, and metal oxide micro-nano powder are added to the coating as high heat transfer medium substances. The coating with a single substance or a mixture of high-efficiency heat transfer mediums greatly improves the thermal conductivity of the organic fluorine coating, offsets the heat transfer reduction caused by the low thermal conductivity of the organic coating on the pipe wall, ensures the necessary thermal conductivity effect, keeps the inner wall of the pipe clean and maintains good heat conduction function, and produces good energy recovery and huge economic benefits.

[0037] In the present application, the heat exchange tube 1-7 is a finned spiral tube. Since the wall of the spiral tube adopts an ultra-thin wall, the heat transfer effect is increased many times, but the compressive and tensile strength are greatly affected. In order to overcome this defect, it is designed to wrap fins of the same material around the outside of the heat exchange tube 1-7 to form an ultra-thin spiral finned heat exchange tube. The fins are made of the same material as the tube, with a thickness × height = 0.5-1 × 10-30mm strip spiral fins. The fins are perpendicular to the radial direction of the tube diameter. The fins are spirally wound around the outside of the heat exchange tube 1-7 at a spacing of 0.5-2 times the tube diameter, and are connected and fixed to the tube wall with molten metal to achieve the effect of enhancing the compressive strength of the inner and outer walls of the heat exchange tube 1-7; the fins and the tube wall of the heat exchange tube 1-7 are fixedly connected with molten metal to enhance the mechanical strength of the heat exchange tube 1-7 and the compressive resistance of the inner and outer walls of the tube wall. , overcome the disadvantage of reduced pipe strength caused by the thin wall of the heat exchange tube 1-7, promote the compressive strength of the thin-walled pipe to be close to or exceed about 4-5Mpa, support the pipe wall of the heat exchange tube 1-7 to improve the compressive strength, achieve the range of heat exchanger that can be used for low-temperature and efficient heat recovery, absorb more low-temperature heat, and reduce waste heat waste; in addition, the heat exchange area can be increased by 20%-40%, the heat transfer area of ​​the heat exchange tube 1-7 is increased, and the heat transfer effect of the heat exchange tube 1-7 is improved.

[0038] The exhaust gas outlet of the air condensation exchanger device 1 is also connected to the liquid inlet of the oil-water separator 4. The spray liquid flushes the inner wall of the heat exchange tube 1-7 and then flows out from the exhaust gas outlet and enters the oil-water separator 4 for oil-water separation. After the oil-water separation, the oil flows out from the oil outlet 10 and the water is discharged from the water outlet 9. The air inlet of the activated carbon adsorption desorber 3 is connected to the liquid inlet of the oil-water separator 4; a small amount of water and oil stains will also be generated in the activated carbon adsorption desorber 3, which will flow out from the air inlet at the bottom of the activated carbon adsorption desorber 3 and enter the oil-water separator 4. The oil-water separator 4 is connected to the spray device 8 in the air condensation exchanger device 1 through the spray water pump 11.

[0039] In addition, an electrostatic precipitator 12 and a first pulse filter 13 are provided between the exhaust port of the printing and dyeing setting machine 5 and the exhaust gas inlet of the air condensation exchanger device 1. The electrostatic precipitator 12 and the first pulse filter 13 can absorb most of the dust impurities in the exhaust gas. The exhaust port of the activated carbon adsorption desorber 3 is also connected to the air inlet of the printing and dyeing setting machine 5 through the second pulse filter 14. The treated exhaust gas has met the emission standards. In this system, most of the treated exhaust gas is discharged into the atmosphere, and a small amount of exhaust gas can be returned to the printing and dyeing setting machine 5 for use again because the temperature of the gas during discharge is higher than the air temperature in the atmosphere.

[0040] There are 8 air condensation exchanger devices 1, and the cooling air outlet 1-10 and the cooling air inlet 1-9 of two adjacent air condensation exchanger devices 1 are connected by a pipe. The exhaust gas inlet 1-2 at the top of each air condensation exchanger device 1 is equipped with an air intake control valve 1-11, and the number of air condensation exchanger devices 1 opened can be determined according to the displacement of the printing and dyeing setting machine 5.

[0041] like Figure 3 As shown, the spraying device 8 includes a self-rotating disk 8-1, a liquid flow pipe 8-2, a nozzle 8-3, a water inlet pipe 8-4 and a fixed frame 8-5. The fixed frame 8-5 is installed on the top of the spray chamber 1-6. There are three liquid flow pipes 8-2, which are installed on the circumference of the self-rotating disk 8-1. The lower part of the water inlet pipe 8-4 is rotatably connected to the self-rotating disk 8-1 and is connected to the liquid flow pipe 8-2 through the self-rotating disk 8-1. The upper part of the water inlet pipe 8-4 is connected to the fixed frame 8-5, and the nozzle 8-3 is provided below the liquid flow pipe 8-2.

[0042] The exhaust gas outlet of the air-to-condensation exchanger device 1 is connected to the liquid inlet of the oil-water separator 4 via a first U-shaped tube 15, and the air inlet of the activated carbon adsorption-desorber 3 is connected to the liquid inlet of the oil-water separator 4 via a second U-shaped tube 16. The use of the first U-shaped tube 15 and the second U-shaped tube 16 acts as a liquid seal, preventing exhaust gas from entering the oil-water separator. During heat recovery production operations, a trace amount of fluorocarbon surfactant is added to the oil-water condensate receiving tank of the oil-water separator 4 at regular intervals and in fixed quantities every day to maintain a certain fluorocarbon surfactant concentration of 0.001%-0.002% in the condensate receiving tank (a characteristic of trace fluorocarbon surfactants). When the spray water pump 11 is activated, the flushing liquid always contains the fluorocarbon surfactant component, continuously flushing the coating surface of the equipment pipeline, ensuring that the coating surface always maintains its hydrophobic, oleophobic and anti-fouling properties, which is an extremely effective measure.

[0043] Example 2

[0044] This embodiment is a method for recovering waste heat from waste gas treatment based on the VOCs treatment waste heat recovery system for the printing and dyeing setting machine in Example 1, specifically comprising the following steps:

[0045] Step 1: After the waste heat gas discharged from the printing and dyeing setting machine is filtered of dust, it enters from the top of the air condensation exchanger device and is dispersed into multiple heat exchange tubes in the spray chamber.

[0046] Step 2: The hot and cold fluids pass through the tube wall to exchange heat between the heat source exhaust fluid in the tube side and the cold source air fluid in the tube wall shell side. The cooled heat source exhaust fluid is discharged from the other end of the heat exchange tube and the air condensation exchanger system is used to recover the excess heat in the exhaust gas discharged under normal temperature conditions. The air condensation exchanger device recovers the excess heat in the exhaust gas and uses the normal temperature air temperature to condense and separate the VOCs in the exhaust gas.

[0047] Step 3: The exhaust gas enters the catalytic cracking burner, where it undergoes high-temperature catalytic cracking and incineration at 300-600°C to remove the remaining VOCs. The gas is then sent to the activated carbon adsorption desorber to absorb the remaining VOCs. Finally, it is discharged into the atmosphere, and a small amount of the treated gas is returned to the printing and dyeing setting machine for recycling.

[0048] Step 4: The spray device sprays the spray liquid into the heat exchange tube, stirring the adhered substances on the tube wall, and promptly washes away the mixed scale of oil, water, fiber and dust impurities adhered to the tube wall. The mixture is discharged into the oil-water separator through the exhaust port at the bottom, where the oil and water are separated and other impurities are precipitated. The separated water is recycled as the subsequent spray liquid;

[0049] Step 5: The cold air is sucked from the atmosphere by the cold air pump as the cold source air fluid and enters the air condensation exchanger device for heat exchange, and is discharged from the cooling air outlet as hot gas and enters the printing and dyeing setting machine;

[0050] Step 6: Cold air is sucked from the atmosphere through a cold air pump as cooling gas in the activated carbon adsorption desorber. After being heated, it becomes hot air and enters the printing and dyeing setting machine; a small amount of oil and water in the activated carbon adsorption desorber enters the oil-water separator for separation.

[0051] Since those skilled in the art can easily think of it, any modifications, equivalent substitutions, improvements, etc. made within the concept and principle of the application should be included in the scope of the claims of this application.

Claims

1. A VOCs treatment waste heat recovery system for a printing and dyeing setting machine, characterized in that: It includes at least one air condensation exchanger device, a catalytic cracking burner, an activated carbon adsorption desorber, an oil-water separator and a printing and dyeing setting machine. The exhaust port of the printing and dyeing setting machine is connected to the exhaust gas inlet of the air condensation exchanger device, the exhaust gas exhaust port of the air condensation exchanger device is connected to the air inlet of the catalytic cracking burner, the exhaust port of the catalytic cracking burner is connected to the air inlet of the activated carbon adsorption desorber, the exhaust port of the activated carbon adsorption desorber is connected to the outside world through an exhaust gas discharge pump, the cooling air inlet of the air condensation exchanger device and the cooling air inlet of the activated carbon adsorption desorber are connected to the outside world through a cold air pump, and the cooling air outlet of the air condensation exchanger device and the cooling air outlet of the activated carbon adsorption desorber are connected to the air inlet of the printing and dyeing setting machine.

2. The VOCs treatment waste heat recovery system for the printing and dyeing setting machine according to claim 1 is characterized in that: The air condensation exchanger device includes a cylinder, a waste gas inlet is provided on the top of the cylinder, a waste gas exhaust port is provided on the bottom, an exchange space is formed in the middle of the cylinder by sealing with a head plate, a spray chamber connected to the waste gas inlet is provided in the upper part of the cylinder, a plurality of heat exchange tubes are installed in the exchange space, the two ends of the heat exchange tubes are respectively connected to the spray chamber and the waste gas exhaust port, a spray device is installed in the spray chamber, and an active agent coating is provided on the inner wall of the heat exchange tube; a cooling air inlet is provided at the lower part of the cylinder, a cooling air outlet is provided at the upper part of the cylinder, and the cooling air inlet and the cooling air outlet are connected to the exchange space.

3. The VOCs treatment waste heat recovery system for a printing and dyeing setting machine according to claim 1 is characterized in that: The exhaust gas outlet of the air condensation exchanger device is also connected to the liquid inlet of the oil-water separator, and the air inlet of the activated carbon adsorption desorber is connected to the liquid inlet of the oil-water separator; the oil-water separator is connected to the spray device of the air condensation exchanger device through a spray water pump.

4. The VOCs treatment waste heat recovery system for a printing and dyeing setting machine according to claim 1 is characterized in that: An electrostatic precipitator and a first pulse filter are also provided between the exhaust port of the printing and dyeing setting machine and the exhaust gas inlet of the air condensation exchanger device. The exhaust port of the activated carbon adsorption desorber is also connected to the air inlet of the printing and dyeing setting machine through the second pulse filter.

5. The VOCs treatment waste heat recovery system for a printing and dyeing setting machine according to claim 1 is characterized in that: The air condensation exchanger devices are provided with 4 to 10 units, and the cooling air outlets and cooling air inlets of two adjacent air condensation exchanger devices are connected through pipelines.

6. The VOCs treatment waste heat recovery system for a printing and dyeing setting machine according to claim 2 is characterized in that: The spray device includes a self-rotating disc, a liquid flow pipe, a nozzle, a water inlet pipe and a fixed frame. The fixed frame is installed on the top of the spray chamber. Several liquid flow pipes are provided and installed on the circumference of the self-rotating disc. The lower part of the water inlet pipe is rotatably connected to the self-rotating disc and is connected to the liquid flow pipe through the self-rotating disc. The upper part of the water inlet pipe is connected to the fixed frame, and the nozzle is arranged below the liquid flow pipe.

7. The VOCs treatment waste heat recovery system for a printing and dyeing setting machine according to claim 3 is characterized in that: The exhaust gas outlet of the air condensation exchanger device is connected to the liquid inlet of the oil-water separator through a first U-shaped tube, and the air inlet of the activated carbon adsorption desorber is connected to the liquid inlet of the oil-water separator through a second U-shaped tube.

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