Energy-saving closed-loop system for recycling heat energy of waste hot gas

Abstract

The utility model provides an energy-saving closed-loop system for recycling heat energy of waste hot gas, which relates to the field of waste heat recovery and comprises a closed-loop station, the inside of the closed-loop station is divided into a combustion cavity, a filter cavity and an exhaust cavity which are sequentially communicated through partition plates, and a low-temperature plasma generator and a high-temperature plasma generator are arranged in the combustion cavity. A first-stage coarse filter is arranged between the combustion cavity and the filter cavity, and a second-stage fine filter is arranged between the filter cavity and the exhaust cavity. The system adopts a solution which is completely different from heat exchange, and is completely not influenced by physical characteristics of heat exchange. After high-temperature waste gas generated by the setting machine is collected, the high-temperature waste gas is subjected to plasma catalysis, combustion and cracking in a plasma area in the system, particulate matters and organic compounds in the high-temperature waste gas are eliminated, hot gas is directly conveyed back to a preheating box and a main heating box of the setting machine after primary rough filtration and secondary fine filtration, and full recycling of the waste gas of the setting machine is achieved.

Description

Technical Field

[0001] This utility model relates to the field of waste heat recovery technology, specifically to an energy-saving closed-loop system for the reuse of waste heat gas thermal energy. Background Technology

[0002] The exhaust gas emitted by stenters in the dyeing and printing industry is high-temperature hot gas, with a temperature ranging from approximately 150-200℃ depending on the type of fabric being processed. The exhaust gas contains: 1. Volatile organic compounds (VOCs), including formaldehyde, benzene, esters, toluene, xylene, and polycyclic aromatic hydrocarbons (PAHs); 2. Particulate matter, including fiber fluff, undissolved resin, dye and auxiliary agent particles, and oil; 3. Inorganic gases, including water vapor and various other harmful components.

[0003] Generally, heat setting machines consume only about 30% of the heat energy used in fabric processing and setting, with about 10% of the heat energy lost from the machine body. The remaining large amount of heat energy (more than 60%) is dissipated into the atmosphere with the exhaust gas, resulting in serious energy waste.

[0004] The existing waste heat recovery system for stenters uses a heat exchange device, but the physical characteristics of the heat exchanger itself determine that its heat recovery efficiency is not high, and it can only recover 50%-60% of the waste gas heat energy. Moreover, the fiber fluff, undissolved resin, dye and auxiliary agent particles, oil and other substances in the waste gas of stenters are easy to clog the heat exchanger and pipelines, making cleaning and maintenance difficult, and the heat recovery efficiency decreases significantly over time. Utility Model Content

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this utility model provides an energy-saving closed-loop system for the reuse of waste heat gas, which achieves heat recovery, purification and efficiency improvement, and capacity enhancement through multi-stage treatment, while reducing waste gas emissions.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, this utility model is implemented through the following technical solution: a waste heat gas thermal energy reuse energy-saving closed-loop system, including a closed-loop station, wherein the closed-loop station is divided into a combustion chamber, a filtration chamber, and an exhaust chamber that are connected in sequence by a partition. The combustion chamber is equipped with a plurality of high-temperature plasma generators. A first-stage coarse filter is provided between the combustion chamber and the filtration chamber, and a second-stage fine filter is provided between the filtration chamber and the exhaust chamber.

[0009] Preferably, a low-temperature plasma generator is also provided inside the combustion chamber.

[0010] Preferably, the exhaust chamber is located at the top of the filter chamber, the second-stage fine filter is located below the exhaust chamber, and a pulse backflush air bag corresponding to the upper and lower parts of the second-stage fine filter is provided at the top of the exhaust chamber.

[0011] Preferably, several second-stage fine filters are arranged side by side.

[0012] Preferably, a funnel-shaped dust collection groove is provided in the exhaust chamber below the second-stage fine filter, and a dust discharge port is provided at the bottom of the dust collection groove.

[0013] Preferably, the energy-saving closed-loop system further includes several styling machines and an induced draft fan. The styling machines are connected to the air inlet of the closed-loop station through air inlet pipes. The induced draft fan is located at the exhaust outlet of the closed-loop station and is connected to the air inlet of the preceding styling machines through an exhaust pipe.

[0014] (III) Beneficial Effects

[0015] This invention provides an energy-saving closed-loop system for the reuse of waste heat gas. It has the following beneficial effects:

[0016] 1. This waste heat gas thermal energy recycling energy-saving closed-loop system adopts a completely different solution from heat exchange, and is entirely unaffected by the physical characteristics of heat exchange. The high-temperature waste gas generated by the stenter is collected and then subjected to low-temperature and high-temperature plasma catalysis, combustion, and pyrolysis in the system's plasma zone to eliminate particulate matter and organic compounds. After primary coarse filtration and secondary fine filtration, the hot gas is directly returned to the stenter's preheating box and main heating box, achieving full recycling of the stenter waste gas. During the recovery process of the stenter waste gas through this system, only the system's own heat loss exists (less than 10%), therefore the heat recovery efficiency of the waste gas can reach over 90%.

[0017] 2. This waste heat gas heat energy recycling energy-saving closed-loop system will not only recycle the waste gas from the stenter, but also burn and crack the particulate matter and organic compounds contained in the waste gas. It can not only effectively utilize the particulate matter and organic compounds in the waste gas to generate new heat, but also effectively treat the pollutants in the waste gas, reducing the pollutant emissions from the stenter. Its VOC pollutant emissions are expected to be reduced by more than 90%. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the closed-loop station of this utility model;

[0019] Figure 2 This is a schematic diagram of the energy-saving closed-loop system of this utility model.

[0020] In the diagram: 1 Closed-loop station, 2 Baffle, 3 Combustion chamber, 4 Filter chamber, 5 Exhaust chamber, 6 Exhaust port, 7 High-temperature plasma generator, 8 Low-temperature plasma generator, 9 First-stage coarse filter, 10 Second-stage fine filter, 11 Dust collection trough, 12 Dust discharge port, 13 Pulse backflushing air manifold, 14 Stenter, 15 Inlet pipe, 16 Exhaust fan, 17 Outlet pipe. Detailed Implementation

[0021] This utility model embodiment provides an energy-saving closed-loop system for the reuse of waste heat gas thermal energy, such as... Figure 1-2 As shown, the system includes several styling machines 14, a closed-loop station 1, and an induced draft fan 16. The styling machines 14 are connected to the air inlet of the closed-loop station 1 via an air inlet pipe 15. The induced draft fan 16 is located at the exhaust port 6 of the closed-loop station 1 and is connected to the air inlet of the preceding styling machines 14 via an exhaust pipe 17. The air inlet pipe 15 is made of insulated stainless steel with an insulation layer thickness >50mm and is seamlessly connected to the exhaust port of the styling machines. The induced draft fan 16 is a high-temperature resistant stainless steel insulated centrifugal fan (temperature resistance 250℃). The exhaust pipe 17 has an insulation layer thickness >50mm, is equipped with a frequency converter (adjustment accuracy ±1%), and has a fan pressure >3000Pa.

[0022] like Figure 1 As shown, the closed-loop station 1 is divided into a combustion chamber 3, a filter chamber 4, and an exhaust chamber 5 that are connected in sequence by a partition 2. The exhaust chamber 5 is located on top of the filter chamber 4.

[0023] The combustion chamber 3 is equipped with several high-temperature plasma generators 7, which are commercially available products (specific specifications may be customized from the manufacturer as needed). Each high-temperature plasma generator 7 has two electrodes (cathode and anode) maintained at an appropriate distance. When a high-voltage current is applied, a large number of electric arcs are generated between the two electrodes. Pressurized gas is used to blow out these arcs, creating a plasma torch with a temperature exceeding 3000K, while also generating active electrons and ions. Temperatures above 3000K can instantly ignite and decompose combustible organic gases, particulate matter, and fibers. The 3000℃ high-temperature plasma flame generated by arc discharge instantly oxidizes and decomposes organic matter in the waste gas into carbon dioxide, water, and inorganic ash. With two or more sets of high-temperature plasma generators 7 (power adjustable from 0-50kW), the decomposition efficiency is >98%.

[0024] A low-temperature plasma generator 8 is also installed inside the combustion chamber 3. The low-temperature plasma generator 8 is a commercially available product (specific specifications may be customized from the manufacturer as needed). During the discharge process, the low-temperature plasma generator produces a large number of free radicals and quasi-molecules, such as OH, O, and NO. These are chemically highly reactive, and therefore their properties can be utilized to treat VOCs. These active ions catalyze the decomposition of organic gases in the waste gas into CO, hydrogen, and water vapor, playing a catalytic and auxiliary role in the high-temperature plasma flame combustion. The use of a radio frequency low-temperature plasma generator to produce low-temperature plasma (high-density active free radicals, electrons, and ions) catalyzes the decomposition of pollutants, assisting the high-temperature plasma flame in completely oxidizing and cracking organic waste gas and pollutants.

[0025] After low-temperature catalysis and high-temperature ignition and pyrolysis, the exhaust gas from the stenter will eventually be decomposed into carbon dioxide, nitrogen dioxide, water vapor and solid ash.

[0026] The partition 2 separating the combustion chamber 3 and the filter chamber 4 is provided with a slot for the first-stage coarse filter 9 to be inserted laterally. The first-stage coarse filter 9 is installed in the slot. The first-stage coarse filter 9 is a stainless steel lint filter with a pore size of 50μm (dust holding capacity of 2kg / m³), and it is replaced once every shift (8 hours) without stopping the machine.

[0027] A second-stage fine filter 10 is installed between the filter chamber 4 and the exhaust chamber 5. The second-stage fine filter 10 is a stainless steel filter with a filter pore size of 5-15μm, serving as a secondary fine filter.

[0028] The second-stage fine filter 10 is located below the exhaust chamber 5, and a pulse backflush air manifold 13, corresponding vertically to the second-stage fine filter 10, is located at the top of the exhaust chamber 5. High-pressure pulse backflush (0.6 MPa) is applied every 10 minutes.

[0029] Several second-stage fine filters 10 are arranged side by side.

[0030] Inside the exhaust chamber 5, below the second-stage fine filter 10, there is a funnel-shaped dust collection trough 11, with a dust discharge port 12 at the bottom. The dust collection trough 11 has a volume of 30L. The funnel-shaped dust collection trough 11 can automatically collect ash, and the dust discharge port 12 below is easy to clean, requiring cleaning every 3-5 days.

[0031] This system also includes a PLC automatic control system, with the PLC control module monitoring temperature, pressure, and concentration parameters in real time.

[0032] This system uses a 10-section stenter as an example for calculation:

[0033] 1. System Configuration:

[0034] High-temperature plasma power: 0-50kW adjustable (pyrolysis temperature >2,000℃); induced draft fan power: 11kW (air volume 0-5,000m³ / h adjustable, fan pressure up to 3.500Pa).

[0035] 2. Performance:

[0036] index Original system This utility model Daily thermal energy cost (RMB) 8500 3900(↓55％) Daily output (10,000 meters of fabric) 6.0 6.6(↑10％) Net profit (RMB / day) 6000 12000(↑100％)

[0037] 3. Economic benefits:

[0038] Annual energy saving benefit: 4,600 yuan / day × 300 days = 1.38 million yuan;

[0039] Annual increase in production revenue: 0.6 million meters / day × 0.30 yuan / meter × 300 days = 540,000 yuan (Note: This is an estimated increase in revenue due to increased output but no increase in energy consumption under the same working conditions when using this system).

[0040] Total revenue: RMB 1.92 million per year; equipment investment payback period: <6 months.

[0041] Although embodiments of the present 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 present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A closed-loop energy-saving system for the reuse of waste heat gas, characterized in that: It includes a closed-loop station (1), which is divided into a combustion chamber (3), a filter chamber (4) and an exhaust chamber (5) in sequence by a partition (2). The combustion chamber (3) is equipped with several high-temperature plasma generators (7). A first-stage coarse filter (9) is provided between the combustion chamber (3) and the filter chamber (4). A second-stage fine filter (10) is provided between the filter chamber (4) and the exhaust chamber (5).

2. The waste heat gas thermal energy reuse energy-saving closed-loop system according to claim 1, characterized in that: A low-temperature plasma generator (8) is also installed inside the combustion chamber (3).

3. The waste heat gas thermal energy reuse energy-saving closed-loop system according to claim 1, characterized in that: The exhaust chamber (5) is located at the top of the filter chamber (4), and the second-stage fine filter (10) is located below the exhaust chamber (5). The top of the exhaust chamber (5) is provided with a pulse backflush air bag (13) corresponding to the second-stage fine filter (10).

4. The waste heat gas thermal energy reuse energy-saving closed-loop system according to claim 3, characterized in that: Several second-stage fine filters (10) are arranged side by side.

5. The waste heat gas thermal energy reuse energy-saving closed-loop system according to claim 3, characterized in that: A funnel-shaped dust collection trough (11) is provided in the exhaust chamber (5) below the second-stage fine filter (10), and a dust discharge port (12) is provided at the bottom of the dust collection trough (11).

6. The waste heat gas thermal energy reuse energy-saving closed-loop system according to claim 1, characterized in that: The energy-saving closed-loop system also includes several styling machines (14) and an exhaust fan (16). The styling machines (14) are connected to the air inlet of the closed-loop station (1) through an air inlet pipe (15). The exhaust fan (16) is located at the exhaust port (6) of the closed-loop station (1). The exhaust fan (16) is connected to the air inlet of the preceding styling machines (14) through an air outlet pipe (17).

Images