A gas absorption tray

Abstract

The utility model discloses a tower tray for gas absorption, which comprises a horizontal tray plate and a spray cover, wherein the horizontal tray plate is provided with plate holes, and a cylindrical gas riser is connected above the plate holes; the spray cover is installed on the plate holes; the spray cover is irregularly shaped, and comprises a cuboid cap cover box and a half-pipe cover box symmetrically arranged on both sides of the cuboid cap cover box; the cuboid cap cover box is in communication with the half-pipe cover box; the cuboid cap cover box is provided with a semicircular hole for communication between the cuboid cap cover box and the half-pipe cover box; a lifting ring, a semicircular baffle in communication with the lifting ring and a rectangular baffle located in the cuboid cap cover box are fixedly arranged in the semicircular hole; the rectangular baffle is used for blocking the semicircular baffle, so as to ensure that the semicircular baffle is opened to the side of the half-pipe cover box, prevent the gas in the half-pipe cover box from flowing back to the cuboid cap cover box and ensure the one-way flow of the gas; the above design solves the technical problem that the existing structure cannot guarantee the one-way flow of the gas in the cap cover box and affects the absorption efficiency.

Description

Technical Field

[0001] This utility model relates to the field of absorption tower trays in the chemical industry, specifically to a gas absorption tower tray. Background Technology

[0002] Gas absorption processes aim to dissolve certain components of a gas mixture in a liquid absorbent to achieve gas separation, purification, or recovery. In traditional gas absorption equipment, the design and performance of the trays have a crucial impact on the absorption effect.

[0003] While traditional trays (such as sieve trays and valve trays) can achieve basic gas-liquid contact under normal operating conditions, they have technical limitations when handling low-concentration gases. Low-concentration gases tend to flow non-uniformly on the surface of traditional trays, and insufficient gas phase kinetic energy leads to "gas flow deviation" at the tray cross-section, creating localized flow dead zones and causing fluid dynamic imbalance. Simultaneously, the reduced gas-liquid contact area results in a sharp drop in mass transfer efficiency, necessitating an increase in the height of the mass transfer unit. Furthermore, existing flow guiding structures cannot maintain effective distribution under low gas velocity conditions, leading to uneven distribution and exposing the core problem of limited operational flexibility, severely restricting the stability and processing efficiency of the low-concentration gas absorption process.

[0004] The aforementioned technical bottlenecks severely restrict the development of emerging environmental protection fields such as low-concentration gas absorption (waste gas treatment, carbon capture, etc.), and there is an urgent need to develop a new type of tray structure that combines efficient gas-liquid distribution characteristics, low pressure drop features, and adaptability to low-concentration operating conditions. Utility Model Content

[0005] The purpose of this invention is to overcome the defects in the prior art and provide a gas absorption tray.

[0006] To achieve the above objectives, this utility model adopts the following technical solution: A gas absorption tray includes a horizontal tray and a spray hood. The horizontal tray has perforations, and a cylindrical gas riser is connected above the perforations. The spray hood is installed on several perforations and is irregularly shaped. It includes a cuboid cap box and semi-tubular covers symmetrically arranged on both sides of the cuboid cap box. The cuboid cap box and the semi-tubular covers are connected. The cuboid cap box has a semi-circular hole for connecting the cuboid cap box and the semi-tubular box. The semi-circular hole is fixed with a hanging ring, a semi-circular baffle connected to the hanging ring, and a rectangular baffle located inside the cuboid cap box. The rectangular baffle is used to block the semi-circular baffle, ensuring that the semi-circular baffle opens to the side of the semi-tubular box, preventing the gas in the semi-tubular box from flowing back into the cuboid cap box, and ensuring the unidirectional flow of gas.

[0007] Preferably, the lifting ring has a notch for fixing to the cuboid cap box and the semi-tubular cover box.

[0008] Preferably, the semi-circular baffle is provided with a connecting hole for connecting with the lifting ring.

[0009] Preferably, the semi-tubular cover is connected to the horizontal tower plate by legs and bolts.

[0010] Preferably, the top of the riser pipe has a skylight.

[0011] Preferably, tear holes are opened on the horizontal tray located between the cuboid cap box and the riser pipe to prevent local liquid accumulation on the tray after shutdown.

[0012] Preferably, a bottom gap is provided between the semi-tubular cover and the horizontal tower plate, and the size of the bottom gap is 5-50mm.

[0013] Preferably, the semi-tubular cover has spray holes, which are symmetrically and evenly arranged around the centerline of the semi-tubular cover.

[0014] Preferably, the cuboid cap box is fixed directly above the plate hole, and the semi-tubular cap box is welded to the cuboid cap box.

[0015] Compared with the prior art, the beneficial effects of this utility model are: This invention incorporates a riser pipe inside the cap, the height of which can be adjusted within a certain range based on the material properties and gas solubility characteristics, thus avoiding the leakage problem of traditional trays under low gas phase loads. By incorporating a spray hood, the gas and liquid phases come into contact and are lifted within the semi-tubular cap, and are evenly distributed in the liquid phase through spray holes on the semi-tubular cap. Excess gas overflows into the liquid phase through the bottom gap, contributing to a balanced gas distribution. The structural features of this invention achieve efficient gas-liquid distribution while maintaining high operational flexibility in the gas phase, ensuring stable operation under low-concentration gas conditions. It improves upon the limitations of traditional tray towers where gas-liquid contact effectiveness is affected by gas distribution and orifice size, thus solving the problems of uneven gas distribution and leakage under low-concentration gas conditions.

[0016] This invention's spray hood comprises a rectangular cap and two symmetrically arranged semi-tubular hoods, which prolong the contact time between the gas and liquid phases, achieving better separation of soluble and insoluble gases, extending the gas residence time on the tray, and ensuring more uniform gas distribution. Simultaneously, it allows for better contact with the liquid phase, resulting in more stable tray operation, lower failure rate, and enhanced safety and reliability. The teardrop-shaped openings prevent localized liquid accumulation on the trays after shutdown, and the semi-circular baffles on the rectangular cap prevent backflow of gas from the semi-tubular hoods back into the rectangular cap, ensuring unidirectional gas flow. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a top view of the present invention; Figure 3 The drawings show the lifting ring, semi-circular baffle, and rectangular baffle of this utility model; Figure 4 This is a schematic diagram of the semi-circular hole of this utility model; Figure 5 This is a flowchart illustrating the specific experimental procedure of this utility model; Figure 6 This is a diagram showing the experimental operation load performance of this utility model.

[0018] In the diagram: 1. Horizontal tray; 2. Tray hole; 3. Riser pipe; 4. Rectangular cap box; 42. Lifting ring; 43. Semi-circular baffle; 431. Connection hole; 44. Rectangular baffle; 5. Semi-tubular cap box; 8. Skylight; 10. Bottom clearance; 11. Injection hole. Detailed Implementation

[0019] A preferred embodiment of the present invention will now be described in conjunction with the accompanying drawings, providing a clear and complete description of the technical solution in this preferred embodiment.

[0020] Example 1: A gas absorption tray includes a horizontal tray 1 and a spray hood. The horizontal tray 1 has perforations 2, and a cylindrical gas riser 3 is connected above the perforations 2. The spray hood is installed on several perforations 2. The spray hood is irregularly shaped and includes a cuboid cap box 4 and semi-tubular hood boxes 5 symmetrically arranged on both sides of the cuboid cap box 4. The cuboid cap box 4 and the semi-tubular hood boxes 5 are connected. The cuboid cap box 4 has a semi-circular hole for connecting the cuboid cap box 4 and the semi-tubular box 5. The semi-circular hole is fixed with a hanging ring 42, a semi-circular baffle 43 connected to the hanging ring 42, and a rectangular baffle 44 located inside the cuboid cap box 4. The rectangular baffle 44 is used to block the semi-circular baffle 43, ensuring that the semi-circular baffle 43 opens to the side of the semi-tubular box 5, preventing gas and liquid in the semi-tubular box 5 from flowing back into the cuboid cap box 4, and ensuring unidirectional flow of gas.

[0021] Through the above design, the liquid phase descends from the upper tray to the horizontal tray 1, remains on this tray, and enters the semi-tubular cover 5 through the bottom gap 10 to contact the gas phase. The gas phase rises from the lower tray to the horizontal tray 1, enters the riser pipe 3 through the plate hole 2, rises along the riser pipe 3, enters the cuboid cap 4 through the skylight 8, and exits through the semi-circular hole to the semi-tubular cover 5 to meet the liquid phase. The liquid phase is supported and stretched on the inner wall of the semi-tubular cover, and then the film is broken and pulverized into many small droplets and dispersed. The mixed gas-liquid mixture is sprayed out from the injection hole 11 on the semi-tubular cover and enters the liquid layer. The liquid phase enters the liquid layer, while the gas phase rises to the upper tray, circulating in the trays to achieve the purpose of mass transfer and heat transfer separation.

[0022] A riser pipe 3 is installed inside the cap, which increases the contact position of the gas and liquid phases on the horizontal tray 1 and helps to achieve a balanced gas distribution. The height of the riser pipe 3 is set within a certain range based on the characteristics of the material properties and gas solubility.

[0023] The spray hood consists of a rectangular cap box 4 and a semi-tubular hood box 5, which allows for a longer contact time between the gas and liquid phases, achieving better separation of soluble and insoluble gases, a longer residence time of the gas on the tray, a more uniform distribution, and better contact with the liquid phase. The trays are stable in operation, have a low failure rate, and are safe and reliable. The overall effect of the trays for low-concentration gas absorption is improved.

[0024] Specifically, hole 2 is circular.

[0025] Through the above design, the combination of the circular plate orifice 2 and the cylindrical riser pipe 3 in this invention is more conducive to concentrating the airflow of low-concentration gas in the initial stage of ascent, reducing turbulence at the plate orifice, and thus improving the initial uniformity of gas distribution after entering the tray. This characteristic is crucial when processing low-concentration gases, effectively improving the "gas flow deviation" phenomenon and facilitating the absorption process of low-concentration gases, resulting in higher mass transfer efficiency.

[0026] Specifically, the lifting ring 42 has a notch for fixing to the cuboid cap box 4 and the semi-tubular cover box 5. The semi-circular baffle 43 has a connecting hole 431 for engaging with the lifting ring 42.

[0027] Through the above design, the lifting ring 42 facilitates the operation of the tray components during equipment installation and maintenance, and the semi-circular baffle 43 effectively prevents the gas and liquid inside the semi-tubular cover 5 from flowing back into the cuboid cover 4, ensuring unidirectional gas flow and helping to further maintain the gas-liquid mass transfer process.

[0028] The opening ratio of the semi-circular baffle 43 has a non-linear relationship with the gas kinetic energy factor. When this invention is used in conditions with extremely low gas phase loads, the opening ratio of the baffle is significantly reduced due to the extremely low gas kinetic energy factor. This allows the gas to pass through a smaller opening in a more concentrated manner, increasing the gas velocity entering the semi-tubular shroud 5 in the absorption area. This enables even a small amount of gas to be quickly dispersed throughout the semi-tubular shroud 5, increasing the gas-liquid contact area and thus improving absorption efficiency. Since the semi-circular baffle 43 can automatically adjust its opening ratio according to the gas kinetic energy factor, no additional energy is needed to drive a complex gas distribution device or adjust the gas flow rate. This allows the design based on the semi-circular baffle to reduce the operating energy consumption of the equipment while ensuring absorption effect, achieving the goal of energy saving and consumption reduction.

[0029] Specifically, the top of the air riser 3 has a skylight 8.

[0030] Through the above design, the skylight 8 works in concert with the entire spray hood and riser pipe 3 structure. During the absorption of low-concentration gas, it can guide the gas to flow along a specific path, enhancing the mixing effect of gas and liquid inside the hood.

[0031] Specifically, tear holes are opened on the horizontal tray 1 located between the cuboid cap box 4 and the riser pipe 3 to prevent local liquid accumulation on the tray after shutdown.

[0032] Specifically, the semi-tubular cover 5 has spray holes 11, which are symmetrically and evenly arranged around the center line of the semi-tubular cover 5.

[0033] Specifically, a bottom gap 10 is provided between the semi-tubular cover 5 and the horizontal tower plate 1, and the size of the bottom gap 10 is 5-50mm.

[0034] This invention, through the aforementioned design, ensures that the flow rates and velocities of the liquid and gas phases entering the semi-tubular casing 5 are matched with the flow velocity of the injection holes 11, achieving a highly efficient jet mixing and mass transfer process between the gas and liquid phases within a specific space. Furthermore, when this invention is used in applications with excessively high gas phase loads, due to the large gas flow rate, not all gas can be ejected from the injection holes 11. In this case, excess gas can overflow into the liquid phase through the bottom gap 10, increasing the gas-liquid contact area. The injection holes 11 are symmetrically and uniformly arranged along the centerline of the semi-tubular casing 5, ensuring uniform gas-liquid contact throughout the entire injection hood space, significantly improving mass transfer efficiency.

[0035] Specifically, the semi-tubular cover 5 is connected to the horizontal tower plate 1 via support legs 7 and bolts. The cuboid cap cover 4 is fixed directly above the plate hole 2, and the semi-tubular cover 5 is welded to the cuboid cap cover 4.

[0036] Through the above design, the present invention forms a detachable structure by welding the semi-tubular cover box 5 and the rectangular cap box 4 together and then connecting them with bolts in the tray. This structure not only ensures the gas-liquid contact time to achieve the effect of the tray for low-concentration gas absorption, but also facilitates maintenance during subsequent production processes.

[0037] Example 2: Cold Model Experiment like Figure 5 As shown: To provide the required operating conditions for the test tray, the equipment includes a fan P2, a water pump P1, a water tank V1, a differential pressure gauge U1, an air flow meter G1, a water flow meter L1, and several valves, all connected by transparent rubber tubing. The material flow of the cold model experimental device is as follows: Air enters the system through the inlet, passes through the fan P2, valve X4, and air flow meter G1, and then enters the test water tank. Inside the test water tank, the air passes through the test tray and is then discharged from the exhaust port 1 above the test water tank, returning to the atmosphere. Water is stored in the water tank V1 and enters the test water tank after passing through the water pump P1, valve X1, and water flow meter L1. Inside the test water tank, the liquid is fed into the test tray and accumulates on it. When the liquid accumulates to a certain height, it overflows from above the overflow weir, enters the downcomer, and flows back to the water tank V1.

[0038] Before starting the device, the air inlet, exhaust port 1, and exhaust port 2 are connected to the atmosphere. At the start of the test, start the fan P2, drawing air in through the air inlet and pressurizing it. By controlling the opening of the fan outlet valve X4 and bypass valve X5, gradually increase and adjust the flow rate indicated by the air flow meter G1 to the specified test flow rate, which is then supplied through the air inlet at the bottom of the test water tank. Start the water pump P1, pressurizing the water in the tank and pumping it into the liquid inlet on the side of the test water tank. By controlling the opening of valve X1 and bypass valve X2, gradually increase and adjust the flow rate indicated by the water flow meter L1 to the specified test flow rate.

[0039] The diameter of the test tray used in the cold model experiment was 500 mm, with a designed liquid flow rate of 2000 L / h and a gas flow rate of 200 m³ / h. The cold model experiment used air and water as raw materials, fixing the water flow rate at 2000 L / h and the air flow rate range at 160–520 m³ / h, simulating the working conditions of an actual absorption tower, and measuring the tray pressure drop of this invention when the air flow rate changed. The table below provides some experimental data from the cold model experiment: Table 1: Experimental Data Table 1 160 0.66 54 2 200 0.69 55 3 240 0.71 55 4 280 0.72 54 5 320 0.80 55 6 360 0.82 57 7 400 0.84 58 8 440 0.87 58 9 480 0.89 59 10 520 0.98 60 The hydraulic performance of the tray of this invention was tested by cold mold experiments, and the load performance of the tray was calculated based on the experimental data, and a load performance diagram was drawn.

[0040] like Figure 6 As shown: The load performance diagram mainly includes the leakage line, entrainment line, flooding line, lower limit of liquid phase load, and upper limit of liquid phase load. Specific explanations are as follows: Leakage line: The minimum gas flow rate required to meet the normal operating conditions of the tray. Due to the structural characteristics of the experimental tray, when the air flow rate is close to 0, the liquid is blocked by the riser pipe, and a small amount of gas forms bubbles from the injection holes and floats to the surface, forming a stable bubbling zone. Therefore, the tray of this invention is suitable for operating conditions where the air flow rate is close to 0, and there is no leakage line.

[0041] Entrainment line: The minimum gas flow rate that can carry a small amount of liquid from a tray into the gas phase. In the experimental tray, when the air flow rate reached approximately 300 m³ / h, the liquid was distributed in a film within the semi-tubular enclosure and ejected from the nozzles and bottom gap. Due to the large gas flow rate, some liquid was sheared and broken into fine droplets by the air, resulting in the entrainment of a small amount of water mist in the gas, thus causing entrainment. Therefore, the entrainment line for the experimental tray was 300 m³ / h.

[0042] Flooding line: The minimum amount of gas that can carry a significant amount of liquid from a tray into the gas phase. In the experimental tray, when the air flow rate reached approximately 500 m³ / h, the liquid experienced violent turbulence on the tray due to the excessive gas flow, causing the liquid to be carried out by the gas from exhaust port 1. Therefore, the flooding line of the experimental tray was 500 m³ / h.

[0043] Liquid load lower limit: When the liquid flow rate is too low, the liquid flow on the plate is uneven, resulting in poor gas-liquid contact. In the experimental tray, when the liquid load is below 0.3 m³ / h, the liquid leaks to the bottom of the tray due to the tear-hole openings on tray 1, causing the liquid on the tray to gradually decrease and fail to overflow smoothly from the overflow weir, resulting in poor gas-liquid contact. Therefore, the lower limit of the liquid load for the experimental tray is 0.3 m³ / h.

[0044] Liquid load limit: Excessive liquid flow rate results in insufficient residence time of the liquid in the downcomer, causing air bubbles to fail to separate and leading to gas being carried out by the liquid. In the experimental tray, when the liquid load exceeds 4.3 m³ / h, gas is carried into the water tank by the liquid; therefore, the upper limit of the liquid load for the experimental tray is 4.3 m³ / h.

[0045] Experimental data shows that, due to its structural advantages, the distillation tray used in this invention does not leak liquid under extremely low gas phase loads, and the gas floats to the water surface in the form of bubbles in the injection holes, forming a bubbling zone. Under high gas phase loads, the liquid is distributed in a film-like manner within the semi-tubular casing under the action of the gas and is ejected from the injection holes and bottom gaps in the form of a gas-liquid mixture. Therefore, this invention, through its innovative structural design, has the advantages of a wide operating range and uniform gas distribution on the tray surface.

[0046] Example 3: To verify the applicability of this utility model tray in the gas absorption process in the chemical industry, further explanation will be provided in conjunction with actual field cases.

[0047] The equipment using the trays of this utility model on site is a hydrogen sulfide absorption tower. An aqueous amine solution is fed into the absorption tower from the top, and the hydrogen sulfide-containing feed gas is fed into the absorption tower from the bottom. Within the absorption tower, hydrogen sulfide is removed from the feed gas through mass transfer. The requirement is to reduce the hydrogen sulfide content in the exhaust gas outside the absorption tower to below 100 ppm. The specific material composition is shown in the table below: Table 2 Detailed Material Composition Table According to the design calculation, the tower has a total of 32 trays. From top to bottom, trays 1 to 16 use the trays of this utility model, and trays 17 to 32 use floating valve trays. After testing and analysis, the hydrogen sulfide content in the exhaust gas at the top of the tower is stable at 46 ppm, and the pressure drop of the entire tower is less than 20 kPa.

[0048] 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 gas absorption tray, characterized in that, It includes a horizontal tower plate (1) and a spray hood. The horizontal tower plate (1) is provided with plate holes (2). A cylindrical gas riser pipe (3) is connected above the plate holes (2). The spray hood is installed on several plate holes (2). The spray hood is irregular in shape and includes a cuboid cap box (4) and a semi-tubular hood box (5) symmetrically arranged on both sides of the cuboid cap box (4). The cuboid cap box (4) and the semi-tubular hood box (5) are connected. The cuboid cap box (4) has a semi-circular hole for connecting the cuboid cap box (4) and the semi-tubular box (5). The semi-circular hole is fixed with a hanging ring (42), a semi-circular baffle (43) connected to the hanging ring (42), and a rectangular baffle (44) located inside the cuboid cap box (4). The rectangular baffle (44) is used to block the semi-circular baffle (43) to ensure that the semi-circular baffle (43) opens to the side of the semi-tubular box (5) to prevent the gas in the semi-tubular box (5) from flowing back into the cuboid cap box (4) and to ensure the unidirectional flow of gas.

2. The gas absorption tray according to claim 1, characterized in that, include: The lifting ring (42) has a notch for fixing to the cuboid cap box (4) and the semi-tubular cap box (5).

3. The gas absorption tray according to claim 1, characterized in that, include: The semi-circular baffle (43) is provided with a connecting hole (431) for connecting with the lifting ring (42).

4. The gas absorption tray according to claim 1, characterized in that, include: The semi-tube type cover box (5) is connected to the horizontal tower plate (1) by the support (7) and bolts.

5. The gas absorption tray according to claim 1, characterized in that, include: The top of the riser pipe (3) has a skylight (8).

6. The gas absorption tray according to claim 1, characterized in that, include: Tear holes are opened on the horizontal tray (1) located between the cuboid cap box (4) and the riser pipe (3) to prevent local liquid accumulation on the tray after shutdown.

7. The gas absorption tray according to claim 1, characterized in that, include: A bottom gap (10) is provided between the semi-tubular cover box (5) and the horizontal tower plate (1), and the size of the bottom gap (10) is 5-50mm.

8. The gas absorption tray according to claim 1, characterized in that, include: The semi-tubular cover (5) has spray holes (11) which are symmetrically and evenly arranged around the center line of the semi-tubular cover (5).

9. The gas absorption tray according to claim 1, characterized in that, include: The cuboid cap box (4) is fixed directly above the plate hole (2), and the semi-tubular cap box (5) is welded to the cuboid cap box (4).

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