Compact condensation VOCs recovery system
The compact VOCs recovery system addresses inefficiencies and safety issues in multi-stage systems by using a liquid nitrogen evaporator and flexible tubes to enhance heat transfer and nitrogen utilization, achieving efficient and safe nitrogen vaporization.
Patent Information
- Application Number
- CN202422347350.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-25
- Publication Date
- 2025-07-15
- Estimated Expiration
- 2034-09-25
AI Technical Summary
The existing multi-stage condensation VOCs recycling system is huge in size, has low heat exchange efficiency, high energy consumption and poses safety hazards.
The compact condensation VOCs recovery system is adopted, and the liquid nitrogen storage tank, liquid nitrogen evaporator and exhaust gas heat exchanger is used to achieve efficient heat exchange through elastic threaded tube bundles. The liquid nitrogen is fully vaporized and deeply cooled. The nitrogen circulates to cool the condensed exhaust gas in multiple heat exchange tube bundles.
It improves heat transfer efficiency, enhances energy utilization and equipment safety, and reduces energy consumption.
Smart Images
Figure CN223106533U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of VOC liquid nitrogen cryogenic systems, in particular to a compact condensation VOCs recovery system. Background Art
[0002] Most of the condensation VOCs (volatile organic compounds, hereinafter referred to as VOCs) recovery systems are multi-stage condensation systems. The incoming waste gas sequentially enters a pre-cooling heat exchanger, an intermediate-cooling heat exchanger, and a cryogenic heat exchanger from the waste gas inlet for cooling and condensation. After each stage of heat exchange, the waste gas passes through the corresponding gas-liquid separator for gas-liquid separation. The condensate flows out by its own weight, while the separated waste gas enters the next-stage heat exchanger for further cooling and condensation. The purified gas after gas-liquid separation in the three-stage gas-liquid separator, due to carrying a large amount of cold energy, reflows to the intermediate-cooling heat exchanger and the pre-cooling heat exchanger, and is discharged to the outside after recovering the cold energy and meeting the standards. The liquid nitrogen flows in the opposite direction to the waste gas flow, sequentially passes through the cryogenic heat exchanger, the intermediate-cooling heat exchanger, and the pre-cooling heat exchanger, and finally discharges nitrogen from the nitrogen outlet. The multi-stage condensation system causes a large volume, low heat exchange efficiency, huge waste of energy, high energy consumption, resulting in an increasing cost year by year, and there are certain safety hazards. Therefore, there is an urgent need for a compact condensation VOCs recovery system with simple process, low energy consumption, and high safety at present. Content of the Utility Model
[0003] In view of this, the purpose of the utility model is to provide a compact condensation VOCs recovery system that can solve or at least mitigate the above problems, so as to improve the heat transfer efficiency, enable the liquid nitrogen to be fully gasified and utilized, improve the energy utilization rate, and improve the safety of the equipment.
[0004] The technical solution provided by the present utility model is: a compact condensing VOCs recovery system, including a liquid nitrogen storage tank, a liquid nitrogen evaporator connected to the liquid nitrogen storage tank, and an exhaust gas heat exchanger connected to the liquid nitrogen evaporator; the liquid nitrogen storage tank is communicated with the evaporator tube bundle in the liquid nitrogen evaporator through a first pipeline, and the liquid nitrogen in the liquid nitrogen storage tank enters the evaporator tube bundle through the first pipeline for gasification, and the gasified nitrogen enters the exhaust gas heat exchanger through a second pipeline communicated with the evaporator tube bundle; the exhaust gas heat exchanger includes a heat exchanger housing and a plurality of heat exchange tube bundles installed in the heat exchanger housing; the plurality of heat exchange tube bundles include a first heat exchange tube bundle, a second heat exchange tube bundle and a third heat exchange tube bundle; a tail gas inlet pipeline, a first purified gas pipeline, a condensate discharge pipeline and a second purified gas pipeline are connected to the heat exchanger housing; the first heat exchange tube bundle is connected between the second pipeline and the third pipeline, and the third pipeline is connected to the liquid nitrogen evaporator; the second heat exchange tube bundle is connected between the fourth pipeline and the fifth pipeline, the fourth pipeline is connected to the liquid nitrogen evaporator, and the fifth pipeline is connected to the nitrogen gas network; the third heat exchange tube bundle is connected between the first purified gas pipeline and the second purified gas pipeline.
[0005] In some embodiments, the first heat exchange tube bundle, the second heat exchange tube bundle and the third heat exchange tube bundle are respectively elastic threaded tubes.
[0006] In some embodiments, the tail gas inlet pipeline is arranged at the middle and lower part of the heat exchanger housing.
[0007] In some embodiments, the gasified nitrogen enters the first heat exchange tube bundle through the second pipeline for heat exchange to cool and condense the tail gas entering the heat exchanger housing. The heat-exchanged nitrogen enters the liquid nitrogen evaporator through the third pipeline communicated with the first heat exchange tube bundle. The cooled nitrogen enters the second heat exchange tube bundle through the fourth pipeline communicated with the liquid nitrogen evaporator for heat exchange again to cool and condense the tail gas entering the heat exchanger housing. The heat-exchanged nitrogen enters the nitrogen gas network through the fifth pipeline communicated with the second heat exchange tube bundle; the separated purified gas enters the third heat exchange tube bundle through the first purified gas pipeline connected to the heat exchanger housing for heat exchange to cool and condense the tail gas entering the heat exchanger housing, and the heat-exchanged purified gas is discharged through the second purified gas pipeline communicated with the third heat exchange tube bundle.
[0008] In some embodiments, the tail gas inlet pipeline is connected to the middle and lower part of the heat exchanger housing.
[0009] In some embodiments, the first purified gas pipeline is connected to the upper end of the heat exchanger housing.
[0010] In some embodiments, the condensate discharge pipeline and the second purified gas pipeline are respectively connected to the lower end of the heat exchanger housing.
[0011] Compared with the prior art, the present utility model has at least the following beneficial effects:
[0012] 1. The process of the compact condensation VOCs recovery system provided by the present utility model is simple, which can improve the heat transfer efficiency, fully gasify and utilize liquid nitrogen, and improve the energy utilization rate and the safety of the equipment.
[0013] 2. In the present utility model, the heat exchange tube bundle is an elastic threaded tube, which improves the heat exchange area per unit volume of the waste gas heat exchanger.
[0014] 3. In the present utility model, the liquid nitrogen evaporator realizes the gasification of liquid nitrogen and the deep cooling of nitrogen through the efficient heat exchange between liquid nitrogen and nitrogen, without relying on other heat sources, and improves the energy utilization rate. Description of the Drawings
[0015] Figure 1 The figure shows a schematic diagram of a compact condensation VOCs recovery system according to an embodiment of the present utility model.
[0016] Description of the reference numerals: 1 - liquid nitrogen storage tank; 11 - first pipeline; 2 - liquid nitrogen evaporator; 21 - evaporator tube bundle; 22 - second pipeline; 3 - waste gas heat exchanger; 31 - heat exchanger housing; 311 - condensate discharge pipeline; 32 - first heat exchange tube bundle; 33 - third pipeline; 34 - fourth pipeline; 35 - second heat exchange tube bundle; 36 - fifth pipeline; 37 - tail gas inlet pipeline; 38 - first purified gas pipeline; 39 - third heat exchange tube bundle; 30 - second purified gas pipeline; 4 - nitrogen pipeline network. Detailed Embodiments
[0017] The following further describes the present utility model in conjunction with the drawings and specific embodiments.
[0018] It should be noted that the following detailed descriptions are all illustrative and are intended to provide further descriptions of the present utility model. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present utility model belongs.
[0019] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present utility model. As used herein, unless otherwise clearly specified in the context, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0020] In the present utility model, terms such as "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "side", "bottom", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only relational terms determined for the convenience of describing the structural relationships of various components or elements of the present utility model, and do not specifically refer to any component or element in the present utility model, and should not be construed as a limitation to the present utility model.
[0021] In the present utility model, terms such as "fixed connection", "connected", "joined" should be understood in a broad sense, which may mean a fixed connection, an integral connection or a detachable connection; it may be directly connected or indirectly connected through an intermediate medium. For those skilled in relevant scientific research or technology in this field, the specific meanings of the above terms in the present utility model can be determined according to specific circumstances, and should not be construed as a limitation to the present utility model.
[0022] As Figure 1 shown, the compact condensation VOCs recovery system provided by the present utility model includes a liquid nitrogen storage tank 1, a liquid nitrogen evaporator 2 connected to the liquid nitrogen storage tank 1, and an exhaust gas heat exchanger 3 connected to the liquid nitrogen evaporator 2. The liquid nitrogen in the liquid nitrogen storage tank 1 exchanges heat efficiently with nitrogen in the liquid nitrogen evaporator 2, the liquid nitrogen is vaporized and the cryogenic temperature of the nitrogen reaches the lowest. The cryogenic nitrogen cools and condenses the exhaust gas in the shell side and tube side in the exhaust gas heat exchanger 3. After gas-liquid separation, purified gas and condensation products (such as condensate) after gas-liquid separation are obtained. Preferably, the temperature of the liquid nitrogen in the liquid nitrogen storage tank 1 is -196 °C.
[0023] The liquid nitrogen storage tank 1 is connected to the evaporator tube bundle 21 in the liquid nitrogen evaporator 2 through the first pipeline 11. The liquid nitrogen in the liquid nitrogen storage tank 1 enters the evaporator tube bundle 21 through the first pipeline 11 for gasification, and the gasified nitrogen enters the waste gas heat exchanger 3 through the second pipeline 22 connected to the evaporator tube bundle 21. Preferably, the evaporator tube bundle 21 is generally a threaded tube. Also preferably, the temperature of the gasified nitrogen is -160 °C. The waste gas heat exchanger 3 includes a heat exchanger housing 31 and a plurality of heat exchange tube bundles installed in the heat exchanger housing 31. Preferably, the plurality of heat exchange tube bundles include a first heat exchange tube bundle 32, a second heat exchange tube bundle 35, and a third heat exchange tube bundle 39. More preferably, the first heat exchange tube bundle 32, the second heat exchange tube bundle 35, and the third heat exchange tube bundle 39 are respectively elastic threaded tubes. The heat exchanger housing 31 is made of stainless steel. The first heat exchange tube bundle 32, the second heat exchange tube bundle 35, and the third heat exchange tube bundle 39 are respectively made of stainless steel. A tail gas inlet pipeline 37 is connected to the heat exchanger housing 31, and the tail gas enters the heat exchanger housing 31 through the tail gas inlet pipeline 37. Preferably, the tail gas inlet pipeline 37 is arranged at the middle and lower part of the heat exchanger housing 31. The upper end of the heat exchanger housing 31 is connected to a first purified gas pipeline 38. The lower end of the heat exchanger housing 31 is connected to a condensate discharge pipeline 311 and a second purified gas pipeline 30. The tail gas enters the waste gas heat exchanger 3 through the tail gas inlet pipeline 37 for cooling and condensation, and the condensate is discharged from the condensate discharge pipeline 311.
[0024] The first heat exchange tube bundle 32 is communicated with the second pipeline 22. The gasified nitrogen enters the first heat exchange tube bundle 32 through the second pipeline 22 for heat exchange to cool and condense the tail gas entering the heat exchanger housing 31. The nitrogen after heat exchange enters the liquid nitrogen evaporator 2 through the third pipeline 33 communicated with the first heat exchange tube bundle 32. Preferably, the temperature of the nitrogen flowing out of the third pipeline 33 is 0°C. The nitrogen flowing out of the third pipeline 33 enters the liquid nitrogen evaporator 2 for cooling, and the nitrogen after cooling flows out through the fourth pipeline 34 communicated with the liquid nitrogen evaporator 2. Specifically, when the liquid nitrogen flows through the evaporator tube bundle 21 in the liquid nitrogen evaporator 2, it can exchange heat with the nitrogen entering the liquid nitrogen evaporator 2 from the third pipeline 33 to cool the nitrogen entering the liquid nitrogen evaporator 2 from the third pipeline 33. Preferably, the temperature of the nitrogen flowing out of the fourth pipeline 34 is -160°C. The cooled nitrogen enters the second heat exchange tube bundle 35 through the fourth pipeline 34 for heat exchange again to cool and condense the tail gas entering the heat exchanger housing 31. The nitrogen after heat exchange enters the nitrogen gas network 4 through the fifth pipeline 36 communicated with the second heat exchange tube bundle 35. Preferably, the temperature of the nitrogen entering the nitrogen gas network 4 is 0°C. The tail gas exchanges heat with the nitrogen in the first heat exchange tube bundle 32 and the second heat exchange tube bundle 35, causing the tail gas to separate into gas and liquid. The condensate drains out through the condensate discharge pipeline 311 by its own weight, and the separated purified gas enters the third heat exchange tube bundle 39 through the first purified gas pipeline 38 connected to the heat exchanger housing 31. Preferably, the temperature of the separated purified gas is -140°C. The separated purified gas entering the third heat exchange tube bundle 39 through the first purified gas pipeline 38 can also exchange heat to cool and condense the tail gas entering the heat exchanger housing 31, and the purified gas after heat exchange is discharged through the second purified gas pipeline 30 communicated with the third heat exchange tube bundle 35.
[0025] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
Claims
1. A compact condensing VOCs recovery system, comprising a liquid nitrogen storage tank, a liquid nitrogen evaporator connected to the liquid nitrogen storage tank, and an exhaust gas heat exchanger connected to the liquid nitrogen evaporator; characterized in that, The liquid nitrogen storage tank is communicated with the evaporator tubes in the liquid nitrogen evaporator through a first pipeline. The liquid nitrogen in the liquid nitrogen storage tank enters the evaporator tubes through the first pipeline for gasification, and the gasified nitrogen enters the waste gas heat exchanger through a second pipeline communicated with the evaporator tubes. The waste gas heat exchanger includes a heat exchanger housing and a plurality of heat exchange tubes installed in the heat exchanger housing. The plurality of heat exchange tubes include a first heat exchange tube, a second heat exchange tube, and a third heat exchange tube. A tail gas inlet pipeline, a first purified gas pipeline, a condensate discharge pipeline, and a second purified gas pipeline are connected to the heat exchanger housing. The first heat exchange tube is connected between the second pipeline and a third pipeline, and the third pipeline is connected to the liquid nitrogen evaporator. The second heat exchange tube is connected between a fourth pipeline and a fifth pipeline. The fourth pipeline is connected to the liquid nitrogen evaporator, and the fifth pipeline is connected to the nitrogen gas network. The third heat exchange tube is connected between the first purified gas pipeline and the second purified gas pipeline.
2. The compact condensation VOCs recovery system according to claim 1, characterized in that, The first heat exchange tube, the second heat exchange tube, and the third heat exchange tube are respectively elastic threaded tubes.
3. The compact condensation VOCs recovery system according to claim 1, wherein, The tail gas inlet pipeline is arranged at the middle and lower part of the heat exchanger housing.
4. The compact condensation VOCs recovery system according to claim 1, wherein, The gasified nitrogen enters the first heat exchange tube through the second pipeline for heat exchange to cool and condense the tail gas entering the heat exchanger housing. The nitrogen gas after heat exchange enters the liquid nitrogen evaporator through the third pipeline communicated with the first heat exchange tube. The nitrogen gas after cooling enters the second heat exchange tube through a fourth pipeline communicated with the liquid nitrogen evaporator for heat exchange again to cool and condense the tail gas entering the heat exchanger housing. The nitrogen gas after heat exchange enters the nitrogen gas network through the fifth pipeline communicated with the second heat exchange tube. The separated purified gas enters the third heat exchange tube through the first purified gas pipeline connected to the heat exchanger housing for heat exchange to cool and condense the tail gas entering the heat exchanger housing, and the purified gas after heat exchange is discharged through the second purified gas pipeline communicated with the third heat exchange tube.
5. The compact condensation VOCs recovery system according to claim 1, wherein, The tail gas inlet pipeline is connected to the middle and lower part of the heat exchanger housing.
6. The compact condensation VOCs recovery system according to claim 1, wherein The first purified gas pipeline is connected to the upper end of the heat exchanger housing.
7. The compact condensation VOCs recovery system according to claim 1, wherein The condensate discharge pipeline and the second purified gas pipeline are respectively connected to the lower end of the heat exchanger housing.