NMP waste heat recovery and condensation integrated heat exchanger
By designing an integrated NMP waste heat recovery and condensation heat exchanger with an inclined structure, the problems of low heat exchange efficiency and high energy consumption in existing NMP recovery systems have been solved, achieving efficient NMP solvent recovery and energy-saving effects.
Patent Information
- Application Number
- CN202520253826.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-17
- Publication Date
- 2026-02-10
- Estimated Expiration
- 2035-02-17
AI Technical Summary
Existing NMP recovery systems suffer from problems such as large footprint, low heat exchange efficiency, high resistance, uneven airflow, and floating liquid, resulting in high energy consumption and difficulty in achieving efficient NMP recovery.
Design an integrated NMP waste heat recovery and condensation heat exchanger, including a gas-to-gas heat exchange zone, a deceleration and air distribution zone, a gas-liquid heat exchange zone, a liquid-blocking and demisting zone, and a liquid collection tank zone. The entire structure is inclined and adopts a cross-flow heat exchanger and aluminum plate vacuum brazing technology. Combined with the deceleration and air distribution zone and the liquid-blocking and demisting zone, it achieves efficient heat exchange and condensation.
It improves heat exchange efficiency by more than double, reduces equipment resistance by 60-80%, reduces material consumption by 20-50%, saves chilled water and energy, extends equipment life, and achieves efficient recovery and energy saving of NMP solvent.
Smart Images
Figure CN223896665U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of waste gas environmental protection and treatment technology, specifically an NMP waste heat recovery and condensation integrated heat exchanger. Background Technology
[0002] During the operation of the coating machine, high-temperature and highly corrosive NMP-containing waste gas is generated. Currently, NMP recovery systems have many problems, such as large footprint, low heat exchange efficiency, high resistance, uneven airflow, and floating liquid. These problems result in high energy consumption of existing NMP recovery systems, which cannot meet the requirements of energy conservation and emission reduction. Furthermore, the NMP recovery liquid is difficult to collect when it converges, making it impossible to achieve efficient NMP recovery liquid collection. Utility Model Content
[0003] The technical problem to be solved by this utility model is to provide an integrated NMP waste heat recovery and condensation heat exchanger, which can solve the problems in the prior art.
[0004] This utility model is achieved through the following technical solution: An NMP waste heat recovery condenser integrated heat exchanger includes a gas-to-gas heat exchange zone, a deceleration and equalization zone, a gas-liquid heat exchange zone, a liquid-blocking and demisting zone, and a liquid collection tank zone. One side of the gas-to-gas heat exchange zone is connected to the deceleration and equalization zone, one side of the deceleration and equalization zone is connected to the gas-liquid heat exchange zone, one side of the gas-liquid heat exchange zone is connected to the liquid-blocking and demisting zone, one end of the liquid-blocking and demisting zone is connected to the liquid collection tank zone, and the other end of the liquid collection tank zone is connected to the gas-to-gas heat exchange zone.
[0005] A further technical solution involves providing a first air inlet, a second air inlet, and an air outlet in the gas-to-gas heat exchange zone. High-temperature, high-concentration NMP waste gas is introduced into the first air inlet. The high-temperature, high-concentration NMP waste gas undergoes heat exchange in the gas-to-gas heat exchange zone, the deceleration and air distribution zone, the gas-liquid heat exchange zone, and the liquid-blocking and demisting zone to generate NMP solvent and become low-temperature, low-concentration NMP waste gas. The low-temperature, low-concentration NMP waste gas introduced into the second air inlet exchanges heat with the high-temperature, high-concentration NMP waste gas introduced into the first air inlet in the gas-to-gas heat exchange zone.
[0006] A further technical solution involves setting the gas-to-gas heat exchange zone, the deceleration and air distribution zone, the gas-liquid heat exchange zone, the liquid blocking and demisting zone, and the liquid collection tank zone at an overall inclination to the horizontal plane.
[0007] In a further technical solution, the overall angle of inclination between the gas-to-gas heat exchange zone, the deceleration and air distribution zone, the gas-liquid heat exchange zone, the liquid blocking and demisting zone, and the liquid collection tank zone and the horizontal plane is 15°.
[0008] A further technical solution involves a first air inlet, a second air inlet, and an air outlet in the gas-to-gas heat exchange zone. High-temperature, high-concentration NMP waste gas is introduced into the first air inlet. After heat exchange, the high-temperature, high-concentration NMP waste gas enters the gas-liquid heat exchange zone, where the waste gas is cooled and the NMP solvent is recovered, transforming the waste gas into low-temperature, low-concentration NMP waste gas. Subsequently, the low-temperature, low-concentration NMP waste gas and NMP solvent pass through the liquid-blocking and demisting zone, where the NMP solvent is deposited at the bottom of the liquid collection tank.
[0009] A further technical solution involves installing a condenser in the gas-liquid heat exchange zone, with chilled water flowing through the tube side of the condenser. The chilled water cools the waste gas and then recovers the NMP solvent.
[0010] In a further technical solution, the temperature of the NMP exhaust gas introduced through the first air inlet is 130°C, the temperature of the chilled water introduced into the condenser of the gas-liquid heat exchange zone from the bottom is 7°C, the temperature of the chilled water flowing out of the condenser of the gas-liquid heat exchange zone from the top is 12°C, the temperature of the NMP exhaust gas introduced through the second air inlet is 20°C, and the temperature of the NMP exhaust gas flowing out of the air outlet is 120°C.
[0011] A further technical solution involves the NMP exhaust gas, after being cooled and condensed, passing through a gas-liquid heat exchange zone and a liquid-blocking and demisting zone, becoming low-temperature, low-concentration NMP exhaust gas. This gas then flows upward through the liquid collection tank, causing the trace amounts of NMP condensate that escaped from the liquid-blocking and demisting zone to settle again.
[0012] The beneficial effects of this utility model are as follows: First, by tilting the heat exchanger as a whole, it facilitates the collection of NMP solvent and chilled water, allowing the NMP solvent to be collected in the collection tank area for easy recovery; the gas-to-gas heat exchange zone uses a cross-flow heat exchanger, realizing heat exchange between low-temperature, low-concentration NMP waste gas and high-temperature, high-concentration NMP waste gas, reducing the cooling capacity required for subsequent condensation and saving chilled water; the deceleration and uniform airflow zone ensures uniform mixing of the waste gas entering the gas-liquid heat exchange zone, and the design of the deceleration and uniform airflow zone reduces the wind speed of the waste gas entering the gas-liquid heat exchange zone, solving the problem of inconsistent cross-sectional wind speeds between the gas-to-gas heat exchange zone and the gas-liquid heat exchange zone, providing a buffer for condensation; the entire heat exchanger uses aluminum plate vacuum brazing technology to prevent cross-flow between the hot and cold sides, and the heat transfer coefficient is 40W / (m²). 2 The concentration of W / (m³) increased to 77.79 W / (m³) at ℃. 2 The heat exchange efficiency is more than double that of traditional gas-to-gas heat exchange and condensation combination methods (·℃). The NMP exhaust gas passes through the liquid-blocking and demisting area to capture and collect the small droplets suspended in the air after condensation, preventing most of the droplets from escaping to the later stage and causing problems such as excessive concentration at the subsequent outlet.
[0013] Second, the air heat exchanger and condenser are cleverly designed as an integrated heat exchanger for heat recovery. Cold energy recovery and condensation are carried out in one device, which achieves energy saving, reduces the amount of cold energy required for subsequent condensation, and saves chilled water.
[0014] Third, the system employs a speed-reducing and uniform airflow zone and a liquid-blocking and demisting zone, which serve as connections between the airflow and the condenser, respectively. This avoids problems such as scale buildup or even blockage at the condenser tube and liquid drift, thus extending the equipment's service life.
[0015] Fourth, it makes full use of equipment space, increases equipment compactness, simplifies heat exchange process, reduces equipment volume, energy consumption, engineering investment and overall floor area, and facilitates inspection and maintenance. At the same time, it reduces material consumption by 20-50% compared with existing gas-to-gas heat exchange and condenser split type, increases heat exchange efficiency by more than 1 times, and reduces equipment resistance by 60-80%. Attached Figure Description
[0016] For ease of explanation, the present invention will be described in detail below with reference to specific embodiments and accompanying drawings.
[0017] Figure 1 This is a schematic diagram of the overall structure of an NMP waste heat recovery and condensation integrated heat exchanger according to the present invention.
[0018] Figure 2 for Figure 1 A partial internal structure diagram in the AA direction;
[0019] The diagram shows the first air inlet 11, the second air inlet 12, and the air outlet 13. Detailed Implementation
[0020] like Figures 1-2 As shown, this utility model will be described in detail. For ease of description, the directions mentioned below are defined as follows: the directions of up, down, left, right, front, and back mentioned below are the same as... Figure 1The projection relationships are consistent in all directions (up, down, left, right, front, back). This utility model discloses an integrated NMP waste heat recovery and condensation heat exchanger, including a gas-to-gas heat exchange zone, a deceleration and equalization zone, a gas-liquid heat exchange zone, a liquid-blocking and demisting zone, and a liquid collection tank zone. The gas-to-gas heat exchange zone is provided with a first air inlet 11, a second air inlet 12, and an air outlet 13. High-temperature, high-concentration NMP waste gas is introduced into the first air inlet 11. One side of the gas-to-gas heat exchange zone is connected to the deceleration and equalization zone, and one side of the deceleration and equalization zone is connected to the gas-liquid heat exchange zone. Gas-liquid heat exchange... One side of the zone is connected to the liquid-blocking and demisting zone, which is connected to one end of the liquid collection tank zone. The other end of the liquid collection tank zone is connected to the gas-to-gas heat exchange zone. The high-temperature, high-concentration NMP exhaust gas undergoes heat exchange in the gas-to-gas heat exchange zone, the deceleration and equalization zone, the gas-liquid heat exchange zone, and the liquid-blocking and demisting zone to generate NMP solvent and become low-temperature, low-concentration NMP exhaust gas. The low-temperature, low-concentration NMP exhaust gas introduced through the second inlet 12 exchanges heat with the high-temperature, high-concentration NMP exhaust gas introduced through the first inlet 11 in the gas-to-gas heat exchange zone.
[0021] Advantageously, the gas-to-gas heat exchange zone, the deceleration and air distribution zone, the gas-liquid heat exchange zone, the liquid baffle and demisting zone, and the liquid collection tank zone are all inclined to the horizontal plane. The direction of the inclination is towards the upper left side, and the inclination angle is preferably 15°. Since the device is designed as a counter-flow high-efficiency plate heat exchanger, the NMP condensate at the hot side outlet needs to be discharged. By designing the internal plates of the heat exchanger in the gas-to-gas heat exchange zone to be arranged vertically and the heat exchanger to be inclined at 15°, it is helpful for the NMP condensate to be discharged quickly and collected in the liquid collection tank zone for recycling together with the condensate in the gas-liquid heat exchange zone.
[0022] Advantageously, high-temperature, high-concentration NMP exhaust gas volatilized from the coating machine oven is introduced into the first air inlet 11 and enters the gas-liquid heat exchange zone after heat exchange. A condenser is installed in the gas-liquid heat exchange zone, and chilled water is introduced into the condenser. The chilled water is used to cool the exhaust gas and recover the NMP solvent, turning the exhaust gas into low-temperature, low-concentration NMP exhaust gas. After passing through the liquid-blocking and demisting zone, the NMP solvent is deposited at the bottom of the liquid collection tank. The low-temperature, low-concentration NMP exhaust gas flows upward and enters the gas-gas heat exchange zone from the second air inlet 12 to exchange heat with the high-temperature, high-concentration NMP exhaust gas. Then it flows out from the air outlet 13 to form high-temperature, low-concentration NMP exhaust gas, thereby achieving energy-saving function.
[0023] Advantageously, the temperature of the NMP exhaust gas introduced through the first air inlet 11 is 130°C, the temperature of the chilled water introduced from the bottom of the condenser in the gas-liquid heat exchange zone is 7°C, the temperature of the chilled water flowing out from the top of the condenser in the gas-liquid heat exchange zone is 12°C, the temperature of the NMP exhaust gas introduced through the second air inlet 12 is 20°C, and the temperature of the NMP exhaust gas flowing out from the air outlet 13 is 120°C.
[0024] Beneficially, the gas-to-gas heat exchange zone condenses part of the NMP exhaust gas, reducing the cooling capacity required for subsequent condensation and saving chilled water.
[0025] Beneficially, the deceleration and uniform airflow zone ensures that the exhaust gas entering the gas-liquid heat exchange zone is mixed evenly. The design of the deceleration and uniform airflow zone reduces the wind speed of the NMP exhaust gas entering the gas-liquid heat exchange zone, solving the problem of inconsistent cross-sectional wind speed between the gas-to-gas heat exchange zone and the gas-liquid heat exchange zone, and providing a buffer for condensation.
[0026] Advantageously, after the exhaust gas is brought to a uniform speed, it passes through a gas-liquid heat exchange zone, and chilled water is introduced into the liquid side to cool the NMP exhaust gas. At this time, a large amount of NMP in the exhaust gas changes from a gaseous state to a liquid state due to the saturated vapor pressure at the corresponding temperature, thereby recovering the NMP solvent.
[0027] Beneficially, the NMP exhaust gas passes through a liquid-blocking and demisting zone where small droplets suspended in the air after condensation are captured and collected, preventing most of the droplets from escaping to the later stages and causing problems such as excessive concentration at the subsequent outlet.
[0028] Advantageously, the NMP exhaust gas after cooling and condensation becomes low-temperature, low-concentration NMP exhaust gas after passing through the gas-liquid heat exchange zone and the liquid-blocking and demisting zone. It then flows upward through the liquid collection tank area, causing the trace amount of NMP condensate that escaped from the liquid-blocking and demisting zone to settle again here.
[0029] Beneficially, the low-temperature, low-concentration NMP exhaust gas introduced from the second air inlet 12 and the high-temperature, high-concentration NMP exhaust gas introduced from the first air inlet 11 exchange heat in the gas-gas heat exchange zone, and then come out from the air outlet 13. At this time, the exhaust gas concentration remains unchanged, but the temperature rises, and it becomes high-temperature, low-concentration exhaust gas, which is then sent back to the coating machine, reducing the heating power of the coating machine, recovering heat, and reducing energy consumption.
[0030] Advantageously, the first air inlet 11, the second air inlet 12 and the air outlet 13 are arranged in a cross-flow manner, that is, the second air inlet 12 and the air outlet 13 form one gas channel, and the first air inlet 11 and the deceleration zone form another gas channel.
[0031] Beneficially, the entire heat exchanger employs aluminum plate vacuum brazing technology to prevent cross-flow between the hot and cold sides, increasing the heat transfer coefficient from 40 W / (m^2·℃) to 77.79 W / (m^2·℃), which is more than double the heat transfer efficiency compared to the traditional combination of gas-to-gas heat exchange and condensation.
[0032] The above are merely specific embodiments of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions conceived without creative effort should be included within the protection scope of this utility model; therefore, the protection scope of this utility model should be determined by the scope defined in the claims.
Claims
1. A waste heat recovery and condensation integrated heat exchanger for NMP (Non-Mechanical Processing), comprising a gas-to-gas heat exchange zone, a speed-reducing and air-equalizing zone, a gas-liquid heat exchange zone, a liquid-blocking and demisting zone, and a liquid collection tank zone, characterized in that, One side of the gas-to-gas heat exchange zone is connected to the deceleration and equalization airflow zone, one side of the deceleration and equalization airflow zone is connected to the gas-liquid heat exchange zone, one side of the gas-liquid heat exchange zone is connected to the liquid-blocking and demisting zone, the liquid-blocking and demisting zone is connected to one end of the liquid collection tank zone, and the other end of the liquid collection tank zone is connected to the gas-to-gas heat exchange zone. The gas-to-gas heat exchange zone, the deceleration and equalization airflow zone, the gas-liquid heat exchange zone, the liquid-blocking and demisting zone, and the liquid collection tank zone are all inclined to the horizontal plane.
2. The NMP waste heat recovery condenser integrated heat exchanger according to claim 1, characterized in that: The gas-to-gas heat exchange zone is provided with a first air inlet (11), a second air inlet (12), and an air outlet (13). High-temperature and high-concentration NMP waste gas is introduced into the first air inlet (11). The high-temperature and high-concentration NMP waste gas undergoes heat exchange in the gas-to-gas heat exchange zone, the deceleration and air distribution zone, the gas-liquid heat exchange zone, and the liquid blocking and demisting zone to generate NMP solvent and become low-temperature and low-concentration NMP waste gas. The low-temperature and low-concentration NMP waste gas introduced into the second air inlet (12) exchanges heat with the high-temperature and high-concentration NMP waste gas introduced into the first air inlet (11) in the gas-to-gas heat exchange zone.
3. The NMP waste heat recovery condensing integrated heat exchanger according to claim 1, characterized in that: The overall angle of inclination between the gas-to-gas heat exchange zone, the deceleration and air distribution zone, the gas-liquid heat exchange zone, the liquid blocking and demisting zone, and the liquid collection tank zone and the horizontal plane is 15°.
4. The NMP waste heat recovery condensing integrated heat exchanger according to claim 2, characterized in that: After heat exchange, the high-temperature, high-concentration NMP waste gas enters the gas-liquid heat exchange zone. In the gas-liquid heat exchange zone, the waste gas is cooled and the NMP solvent is recovered, turning the waste gas into low-temperature, low-concentration NMP waste gas. After passing through the liquid-blocking and demisting zone, the NMP solvent is deposited at the bottom of the liquid collection tank.
5. The NMP waste heat recovery condenser integrated heat exchanger according to claim 4, characterized in that: A condenser is installed in the gas-liquid heat exchange zone, and chilled water is introduced into the condenser to cool the waste gas and recover NMP solvent.
6. The NMP waste heat recovery condensing integrated heat exchanger according to claim 4, characterized in that: After being cooled and condensed, the NMP exhaust gas passes through the gas-liquid heat exchange zone and the liquid-blocking and demisting zone, becoming low-temperature, low-concentration NMP exhaust gas. The trace amounts of NMP condensate that escaped from the liquid-blocking and demisting zone settle again through the upward flow channel set in the liquid collection tank area.
7. The NMP waste heat recovery condensing integrated heat exchanger according to claim 5, characterized in that: The chilled water temperature entering the condenser from the bottom of the gas-liquid heat exchange zone is 7°C, and the chilled water temperature exiting the condenser from the top of the gas-liquid heat exchange zone is 12°C.
8. An integrated NMP waste heat recovery and condensation heat exchanger according to any one of claims 1-7, characterized in that: The temperature of the NMP exhaust gas introduced into the first air inlet (11) is 130°C.
9. An integrated NMP waste heat recovery and condensation heat exchanger according to any one of claims 1-7, characterized in that: The temperature of the NMP exhaust gas introduced into the second air inlet (12) is 20°C, and the temperature of the NMP exhaust gas flowing out of the air outlet (13) is 120°C.