A waste heat recovery system for dyeing and printing

Abstract

This invention relates to the field of textile printing and dyeing, and discloses a waste heat recovery system for printing and dyeing, including a printing and dyeing box, a drying box, a heat exchanger, and a wastewater deep treatment box. The discharge port of the printing and dyeing box and the inlet of the drying box are connected by a conveyor belt. A wastewater input pipe is connected between the wastewater discharge port of the printing and dyeing box and the high-temperature inlet of the heat exchanger. A wastewater output pipe is connected between the low-temperature discharge port of the heat exchanger and the inlet of the wastewater deep treatment box. A dye input pipe is connected to the low-temperature inlet of the heat exchanger, and a dye output pipe is connected between the high-temperature discharge port of the heat exchanger and the dye inlet of the printing and dyeing box. A waste heat recovery component is installed on the drying box. This waste heat recovery system makes full use of the heat from the printing and dyeing wastewater to preheat new dyes, achieving resource reuse and saving the resource costs required for printing and dyeing.

Description

Technical Field

[0001] This invention relates to the field of textile printing and dyeing, specifically to a waste heat recovery system for printing and dyeing. Background Technology

[0002] The dyeing and printing industry is both a major water user and a major wastewater discharger. Currently, environmental problems such as water use and wastewater treatment in dyeing and printing enterprises are becoming increasingly prominent. The environmental capacity in many developed areas of my country's dyeing and printing industry is already very limited. During the dyeing and printing process, the boiling, bleaching and high-temperature washing processes generate high-temperature wastewater with temperatures exceeding 80°C. However, the water body and heat energy contained in the dyeing and printing wastewater can be reused. If it is directly discharged into the wastewater equalization tank, the wastewater temperature in the treatment system will reach above 46°C, which will reduce the efficiency of biochemical treatment and cause energy waste. Therefore, we propose a waste heat recovery system for dyeing and printing. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a waste heat recovery system for dyeing and printing, which solves the aforementioned problems.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution: a waste heat recovery system for dyeing and printing, comprising a dyeing and printing box, a drying box, a heat exchanger, and a wastewater deep treatment box. The outlet of the dyeing and printing box is connected to the inlet of the drying box via a conveyor belt. A wastewater input pipe is connected between the wastewater outlet of the dyeing and printing box and the high-temperature inlet of the heat exchanger. A wastewater output pipe is connected between the low-temperature outlet of the heat exchanger and the inlet of the wastewater deep treatment box. A dye input pipe is connected to the low-temperature inlet of the heat exchanger, and a dye output pipe is connected between the high-temperature outlet of the heat exchanger and the dye inlet of the dyeing and printing box. A waste heat recovery component is provided on the drying box.

[0005] Preferably, the heat exchanger uses spiral heat exchange tubes. The absence of right-angle protrusions or grooves in the heat exchange tubes greatly avoids the problem of dust accumulation, while also disturbing the fluid on both sides of the tube wall to improve the heat exchange effect.

[0006] Preferably, the waste heat recovery assembly includes an exhaust fan, a preheating cover plate, and a hot air conveying pipe. A hot air connecting pipe is fixedly connected to the outer side wall of the drying box near the discharge port, and the drying box is connected to the exhaust fan. A hot air conveying pipe is fixedly connected to the air outlet side of the exhaust fan. Two sets of mounting plates are fixedly installed on the upper two sides of the drying box corresponding to the inlet, and a preheating cover plate is fixedly installed on the drying box through the two sets of mounting plates. Multiple sets of air jet nozzles are fixedly provided at the bottom end of the preheating cover plate, and the end of the hot air conveying pipe away from the exhaust fan is fixedly connected to the preheating cover plate.

[0007] Preferably, the heat exchanger is provided with an integrated feed hopper at the high-temperature feed port connected to the wastewater input pipe. An impurity filter plate is fixedly installed between the inner walls of the feed hopper, and a cleaning mechanism is provided inside the feed hopper corresponding to the upper surface of the impurity filter plate. A residual material discharge port is opened at one end of the feed hopper.

[0008] Preferably, the bottom inner wall of the residual material discharge port is flush with the upper surface of the impurity filter plate, and a manual closing door assembly is provided in the residual material discharge port.

[0009] Preferably, the cleaning mechanism includes a drive motor, a threaded screw, and a movable horizontal plate. Two sets of threaded screws are rotatably installed on both sides of the inside of the feed hopper, corresponding to the impurity filter plate. The length of the residual material discharge outlet is less than the distance between the two sets of threaded screws. A movable horizontal plate perpendicular to the impurity filter plate is threaded onto the two sets of threaded screws. A brush strip that fits against the upper surface of the impurity filter plate is fixed at the bottom end of the movable horizontal plate. Two sets of drive motors are fixedly installed on the side wall of the feed hopper away from the residual material discharge outlet, and the output shafts of the two sets of drive motors are fixedly connected to the threaded screws.

[0010] Preferably, the sealing door assembly includes a sealing plate, a cavity groove, and a threaded pull rod. A cavity groove of the same length and connected to the residual material discharge outlet is provided above the residual material discharge outlet in the feed hopper. A sealing plate that can close the residual material discharge outlet is slidably engaged in the cavity groove. The height of the sealing plate is greater than the height of the residual material discharge outlet, and the opening height of the cavity groove is greater than the height of the sealing plate. A threaded pull rod is threadedly inserted into the top outer wall of the feed hopper corresponding to the cavity groove. The bottom end of the threaded pull rod extends into the cavity groove and is rotatably connected to the top end of the sealing plate.

[0011] Compared with the prior art, the present invention provides a waste heat recovery system for dyeing and printing, which has the following beneficial effects:

[0012] 1. In this dyeing and printing waste heat recovery system, when waste heat is recovered after dyeing and printing are completed, high-temperature dyeing wastewater from the dyeing and printing tank is injected into a heat exchanger through a wastewater inlet pipe. New low-temperature dye can also be injected into the heat exchanger through a dye inlet pipe, allowing the new dye to exchange heat with the high-temperature dyeing wastewater. This preheating of the new dye by the high-temperature wastewater fully utilizes waste resources. After heat exchange, the high-temperature dyeing wastewater becomes low-temperature dyeing wastewater and flows into a wastewater deep treatment tank through a wastewater outlet pipe for further treatment. The low-temperature new dye, after heat exchange, becomes high-temperature dye and is injected into the dyeing and printing tank through a dye outlet pipe. The dyeing process begins a new dyeing operation in the dyeing box. This waste heat recovery system fully utilizes the heat from the dyeing wastewater to preheat the new dye, achieving resource reuse and saving on dyeing costs. After the dyed fabric enters the drying box, just before it is discharged, the exhaust fan and hot air connection pipe can be activated to extract the high-temperature air from inside the drying box, accelerating the cooling of the fabric. At the same time, the high-temperature air is sent into the preheating hood through the hot air delivery pipe to form a high-temperature jet, thus preheating the fabric before drying. This makes the recovery and utilization of waste heat from the dyeing process more efficient and saves energy resources.

[0013] 2. In this waste heat recovery system for printing and dyeing, when high-temperature printing and dyeing wastewater is discharged into the heat exchanger through the wastewater inlet pipe and feed hopper for heat exchange, the high-temperature printing and dyeing wastewater is filtered by the impurity filter plate in the feed hopper. The textile impurities (flocculent matter) in the printing and dyeing wastewater are trapped on the surface of the impurity filter plate, thereby preventing the printing and dyeing wastewater containing impurities from entering the heat exchanger. Subsequently, the impurities trapped on the surface of the impurity filter plate are cleaned to ensure the subsequent filtration effect of the impurity filter plate. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the present invention;

[0015] Figure 2 This is a schematic diagram of the dryer structure of the present invention;

[0016] Figure 3 This is a schematic diagram of the heat exchanger of the present invention;

[0017] Figure 4 This is a schematic diagram of the cleaning mechanism structure of the present invention;

[0018] Figure 5 This is a schematic diagram of the structure of the closed door assembly of the present invention.

[0019] In the diagram: 1. Dyeing box; 2. Drying box; 3. Heat exchanger; 4. Wastewater deep treatment box; 5. Wastewater inlet pipe; 6. Wastewater outlet pipe; 7. Dye inlet pipe; 8. Dye outlet pipe; 9. Waste heat recovery assembly; 10. Hot air connection pipe; 11. Exhaust fan; 12. Preheating cover plate; 13. Mounting horizontal plate; 14. Hot air conveying pipe; 15. Feed hopper; 16. Residue discharge port; 17. Impurity filter plate; 18. Cleaning mechanism; 19. Drive motor; 20. Threaded screw; 21. Moving horizontal plate; 22. Brush strip; 23. Sealing plate; 24. Cavity groove; 25. Threaded tie rod. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Please see Figure 1-5 A waste heat recovery system for dyeing and printing includes a dyeing box 1, a drying box 2, a heat exchanger 3, and a wastewater deep treatment box 4. The outlet of the dyeing box 1 and the inlet of the drying box 2 are connected by a conveyor belt. A wastewater inlet pipe 5 connects the wastewater outlet of the dyeing box 1 to the high-temperature inlet of the heat exchanger 3. A wastewater outlet pipe 6 connects the low-temperature outlet of the heat exchanger 3 to the inlet of the wastewater deep treatment box 4. A dye inlet pipe 7 connects the low-temperature inlet of the heat exchanger 3, and a dye outlet pipe 8 connects the high-temperature outlet of the heat exchanger 3 to the dye inlet of the dyeing box 1. A waste heat recovery component 9 is installed on the drying box 2. When waste heat recovery is performed after dyeing and printing, the wastewater is discharged through the wastewater inlet pipe 5. High-temperature dyeing wastewater from dyeing tank 1 is injected into heat exchanger 3, and new low-temperature dye can be injected into heat exchanger 3 through dye inlet pipe 7, so that the new dye and high-temperature dyeing wastewater exchange heat, and the high-temperature dyeing wastewater is used to preheat the new dye, making full use of waste resources. After heat exchange, the high-temperature dyeing wastewater becomes low-temperature dyeing wastewater, and flows into wastewater deep treatment tank 4 through wastewater outlet pipe 6 for wastewater treatment. After heat exchange, the low-temperature new dye becomes high-temperature dye, and is injected into dyeing tank 1 through dye outlet pipe 8 for a new dyeing operation. This waste heat recovery system makes full use of the heat of dyeing wastewater to preheat the new dye, forming a cycle.

[0022] Heat exchanger 3 uses spiral heat exchange tubes. The spiral heat exchange tubes in the heat exchanger have no right-angle protrusions or grooves, which can greatly avoid the problem of dust accumulation. At the same time, they disturb the fluid on both sides of the tube wall and improve the heat exchange effect.

[0023] The waste heat recovery assembly 9 includes an exhaust fan 11, a preheating cover 12, and a hot air conveying pipe 14. A hot air connecting pipe 10 is fixedly connected to the outer side wall of the drying chamber 2 near the discharge port, and the drying chamber 2 is connected to the exhaust fan 11. The hot air conveying pipe 14 is fixedly connected to the air outlet side of the exhaust fan 11. Two sets of mounting horizontal plates 13 are fixedly installed on the upper sides of the drying chamber 2 corresponding to the inlet, and the preheating cover 12 is fixedly installed on the drying chamber 2 through the two sets of mounting horizontal plates 13. Multiple sets of air jets are fixedly installed at the bottom end of the preheating cover 12. The hot air conveying pipe 14, at the end away from the exhaust fan 11, is fixedly connected to the preheating cover plate 12. After the dyed fabric enters the drying chamber 2 for drying, when the fabric is about to be discharged, the exhaust fan 11 and the hot air connecting pipe 10 can be braked to extract the high-temperature air inside the drying chamber 2, which can accelerate the cooling of the fabric. At the same time, the high-temperature air is sent into the preheating cover plate 12 through the hot air conveying pipe 14 to form a high-temperature jet, thereby preheating the fabric before drying. This makes more efficient use of the waste heat in the dyeing process and saves energy resources.

[0024] An integrated feed hopper 15 is provided on the heat exchanger 3 at the high-temperature feed port connected to the wastewater input pipe 5. An impurity filter plate 17 is fixedly installed between the inner walls of the feed hopper 15, and a cleaning mechanism 18 is provided inside the feed hopper 15 corresponding to the upper surface of the impurity filter plate 17. A residual material discharge port 16 is opened at one end of the feed hopper 15. When the high-temperature dyeing wastewater is discharged into the heat exchanger 3 through the wastewater input pipe 5 and the feed hopper 15 for heat exchange, the high-temperature dyeing wastewater is filtered by the impurity filter plate 17 in the feed hopper 15, which will retain the textile impurities (flocculent matter) in the dyeing wastewater on the surface of the impurity filter plate 17, thereby preventing the dyeing wastewater containing impurities from entering the heat exchanger 3. Subsequently, the impurities retained on the surface of the impurity filter plate 17 are cleaned by the cleaning mechanism 18.

[0025] The bottom inner wall of the residual material discharge port 16 is flush with the upper surface of the impurity filter plate 17, and a manual closing door assembly is provided in the residual material discharge port 16.

[0026] The cleaning mechanism 18 includes a drive motor 19, a threaded screw 20, and a movable cross plate 21. Two sets of threaded screws 20 are rotatably installed on both sides of the inside of the feed hopper 15, corresponding to the upper part of the impurity filter plate 17. The length of the residual material discharge port 16 is less than the distance between the two sets of threaded screws 20. The movable cross plate 21, which is perpendicular to the impurity filter plate 17, is threaded onto the two sets of threaded screws 20. The bottom end of the movable cross plate 21 is fixedly provided with a bristle strip 22 that is in contact with the upper surface of the impurity filter plate 17. Two sets of drive motors 19 are fixedly installed on the side wall of the feed hopper 15 away from the residual material discharge port 16, and the output shafts of the two sets of drive motors 19 are fixedly connected to the threaded screws 20.

[0027] The sealing door assembly includes a sealing baffle 23, a cavity groove 24, and a threaded pull rod 25. A cavity groove 24, which is the same length as and communicates with the residual material discharge outlet 16, is opened above the feed hopper 15. The sealing baffle 23, which can close the residual material discharge outlet 16, is slidably engaged in the cavity groove 24. The height of the sealing baffle 23 is greater than the height of the residual material discharge outlet 16, and the opening height of the cavity groove 24 is greater than the height of the sealing baffle 23. A threaded pull rod 25 is threadedly inserted into the top outer wall of the feed hopper 15 above the cavity groove 24. The bottom end of the threaded pull rod 25 extends into the cavity groove 24 and is rotatably connected to the top end of the sealing baffle 23.

[0028] Working principle: When waste heat is recovered after dyeing and printing, the high-temperature dyeing wastewater in the dyeing and printing tank 1 is injected into the heat exchanger 3 through the wastewater inlet pipe 5. New low-temperature dye can also be injected into the heat exchanger 3 through the dye inlet pipe 7, allowing the new dye to exchange heat with the high-temperature dyeing wastewater. This preheating of the new dye by the high-temperature wastewater fully utilizes waste resources. After heat exchange, the high-temperature dyeing wastewater becomes low-temperature dyeing wastewater and flows into the wastewater deep treatment tank 4 through the wastewater outlet pipe 6 for further treatment. The new low-temperature dye, after heat exchange, becomes high-temperature dye and is injected into the dyeing and printing tank 1 through the dye outlet pipe 8. A new dyeing and printing operation is carried out; the waste heat recovery system makes full use of the heat of dyeing and printing wastewater to preheat the new dye, so as to achieve resource reuse and save the resource cost of dyeing and printing; after the dyed fabric enters the drying box 2 for drying, when the fabric is about to be discharged, the exhaust fan 11 and the hot air connection pipe 10 can be braked to extract the high temperature air inside the drying box 2, which can accelerate the cooling of the fabric. At the same time, the high temperature air is sent into the preheating cover plate 12 through the hot air conveying pipe 14 to form a high temperature jet, so as to preheat the fabric before drying, making more efficient use of waste heat in the dyeing and printing process and saving energy resources;

[0029] When high-temperature dyeing wastewater is discharged into heat exchanger 3 through wastewater inlet pipe 5 and feed hopper 15 for heat exchange, the wastewater is filtered by impurity filter plate 17 in feed hopper 15, which traps textile impurities (flocculent matter) on the surface of impurity filter plate 17, thus preventing wastewater containing impurities from entering heat exchanger 3. After the wastewater is discharged, the brake drive motor 19 can drive two sets of threaded screws 20 to rotate. According to the screw principle, the moving horizontal plate 21 can move laterally along the surface of impurity filter plate 17, and the brush strips 22 at the bottom of the moving horizontal plate 21 can clean the impurities trapped on the surface of impurity filter plate 17, thereby ensuring the subsequent filtration effect of impurity filter plate 17. During cleaning, the moving horizontal plate 21 moves laterally towards the residual material discharge outlet 16. After cleaning, the threaded pull rod 25 can be rotated to move the sealing plate 23 into the cavity groove 24, thereby opening the residual material discharge outlet 16 to process the cleaned material.

[0030] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A printing and dyeing waste heat recovery system, comprising a printing and dyeing box (1), a drying box (2), a heat exchanger (3) and a wastewater advanced treatment box (4), the discharge port of the printing and dyeing box (1) is connected with the feeding port of the drying box (2) through a conveying belt, characterized in that: The wastewater input pipe (5) is connected between the wastewater discharge outlet of the printing and dyeing box (1) and the high-temperature inlet of the heat exchanger (3), the wastewater output pipe (6) is connected between the low-temperature discharge outlet of the heat exchanger (3) and the inlet of the wastewater advanced treatment box (4), the dye input pipe (7) is connected to the low-temperature inlet of the heat exchanger (3), and the dye output pipe (8) is connected between the high-temperature discharge outlet of the heat exchanger (3) and the dye inlet of the printing and dyeing box (1), the waste heat recovery assembly (9) is arranged on the drying box (2), the spiral heat exchange pipe is arranged in the heat exchanger (3), the waste heat recovery assembly (9) comprises the air extractor (11), the preheating cover plate (12) and the hot gas conveying pipe (14), the hot air connecting pipe (10) is fixedly connected to the side outer wall of the drying box (2) close to the discharge outlet, the drying box (2) is connected to the air extractor (11) through the hot air connecting pipe (10), the air outlet side of the air extractor (11) is fixedly connected to the hot gas conveying pipe (14), two groups of installation horizontal plates (13) are fixedly installed on the upper sides of the drying box (2) corresponding to the inlets, and the drying box (2) is fixedly installed with the preheating cover plate (12) through the two groups of installation horizontal plates (13), a plurality of air jet nozzles are fixedly arranged at the bottom end of the preheating cover plate (12), one end, away from the air extractor (11), of the hot gas conveying pipe (14) is fixedly connected to the preheating cover plate (12), the integrated feeding hopper (15) is arranged at the high-temperature inlet of the heat exchanger (3) corresponding to the wastewater input pipe (5), the impurity filtering plate (17) is fixedly installed between the inner walls of the feeding hopper (15), the cleaning mechanism (18) is arranged on the upper surface of the impurity filtering plate (17) in the feeding hopper (15), the residual material discharge outlet (16) is formed at one end of the feeding hopper (15), the bottom end inner wall of the residual material discharge outlet (16) is flush with the upper surface of the impurity filtering plate (17), and the manual closing door assembly is arranged in the residual material discharge outlet (16), the cleaning mechanism (18) comprises the driving motor (19), the threaded screw rod (20) and the moving horizontal plate (21), two groups of threaded screw rods (20) are rotatably installed on the two sides of the feeding hopper (15) corresponding to the upper surface of the impurity filtering plate (17), the length of the residual material discharge outlet (16) is less than the interval distance of the two groups of threaded screw rods (20), the moving horizontal plate (21) perpendicular to the impurity filtering plate (17) is threadedly connected to the two groups of threaded screw rods (20), the brush strip (22) is fixedly arranged at the bottom end of the moving horizontal plate (21) and is attached to the upper surface of the impurity filtering plate (17), two groups of driving motors (19) are fixedly installed on the side wall of the feeding hopper (15) away from the residual material discharge outlet (16), and the output shafts of the two groups of driving motors (19) are fixedly connected to the threaded screw rods (20), the closing door assembly comprises the blocking plate (23), the cavity groove (24) and the threaded pull rod (25), the cavity groove (24) having the same length as the residual material discharge outlet (16) and being communicated with the residual material discharge outlet (16) is formed in the feeding hopper (15) corresponding to the upper surface of the residual material discharge outlet (16),The cavity groove (24) is slidably connected with a blocking plate (23) which can close the residual material discharge port (16). The height of the blocking plate (23) is greater than the height of the residual material discharge port (16), and the opening height of the cavity groove (24) is greater than the height of the blocking plate (23). The feeding hopper (15) is threadedly connected with a threaded pull rod (25) at the top end of the outer wall above the cavity groove (24). The bottom end of the threaded pull rod (25) extends into the cavity groove (24) and is rotatably connected with the top end of the blocking plate (23).

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