An acid gas absorption tank

Abstract

This utility model discloses an acidic gas absorption tank, comprising an atomizing tank and a liquid tank connected by an outlet pipe and an inlet pipe. One end of the outlet pipe is connected to a gas collection area, and the other end is positioned below the liquid surface in the liquid tank. One end of the inlet pipe is located at the bottom of the liquid tank, and the other end is connected to the inlet of the atomizing disc. An arc-shaped or wavy filter screen at the top of the atomizing tank divides the inner cavity of the atomizing tank into a gas collection area and an atomizing area, with the atomizing disc positioned in the atomizing area. A gas cavity is formed between the upper and lower discs of the atomizing disc, connected to the inlet pipe. The lower disc is a disc-shaped structure with a concave center, and the gas center hole and the outer conical surface of the liquid inlet of the upper disc form an outlet ring. An auxiliary hole is provided on the concave conical surface of the lower disc. A float valve is installed at the inlet of the absorbent liquid in the liquid tank, and a matching hole can be added to the outer circumferential plane of the lower disc. This utility model utilizes the high-pressure cracked gas sprayed through the outlet ring and auxiliary holes to atomize the absorbent liquid into fine droplets, increasing the contact area between the gas and liquid phases and promoting the absorption of acidic gas by the absorbent liquid.

Description

Technical Field

[0001] This invention is applied in the chemical industry and relates to the removal of acidic gases from ethylene cracking gas, specifically an absorption tank that uses an absorbent liquid to absorb the acidic gases. Background Technology

[0002] During ethylene production, the cracked gas from hydrocarbon cracking needs to be compressed, have acid wash gases removed, dried, and refrigerated in a compression system. The acidic gases in the cracked gas are mainly carbon dioxide, hydrogen sulfide, and other gaseous sulfides, which are typically removed by alkaline washing or by washing with monoethanolamine and diethanolamine absorbents. The waste alkaline solution after alkaline washing needs to be treated to meet discharge standards, and the treatment cost for large quantities of waste alkaline solution is high. Ethanolamine absorbents have drawbacks such as equipment corrosion, volatility, and high regeneration energy consumption. CN119499859A describes a CO2 capturing absorbent, capturing and regenerating device, and capturing process, using ionic liquids as a novel acidic gas absorbent. Ionic liquids have advantages such as high thermal stability, low vapor pressure, and low corrosivity; their vapor pressure is almost zero, resulting in minimal loss during use. They also exhibit good absorption capacity and regeneration ability. Ionic liquids are highly designable and have ideal absorption effects, gradually becoming a major research focus for acidic gas absorption.

[0003] CN202161913U discloses an acidic gas absorption device. The absorbent liquid is pumped out, passes through a cooler, and then flows at high speed through a Laval nozzle. A negative pressure is created in the gas-liquid mixing chamber, drawing in acidic gas and mixing it with the highly turbulent absorbent liquid. The liquid resulting from the reaction of the absorbed gas and absorbent liquid flows out of the absorber and into an absorbent liquid storage tank for further absorption of acidic gas until all effective components in the absorbent liquid have been absorbed and reacted. CN204768217U discloses a device for removing acidic gases from chemical exhaust gases. The absorbent liquid inlet at the top of a spray absorption tower is connected to a spray head, and the chemical exhaust gas inlet is connected to an upward-facing jet head. The spray head is located directly above the jet head, and a conical shielding cap is installed on the jet head, causing the gas to turbulent and greatly increasing the contact area between the mist-like absorbent liquid and the gas, thus improving the absorption efficiency. The above technical solutions limit the absorption efficiency of acidic gases due to the limited gas-liquid contact area. Utility Model Content

[0004] The technical problem solved by this utility model is to provide an acid gas absorption tank that uses high-pressure cracked gas to atomize the absorption liquid, enhances the gas-liquid contact, and improves the efficiency of removing acid gases by increasing the gas-liquid contact area.

[0005] The technical solution adopted in this utility model is as follows: The acidic gas absorption tank of this utility model includes an atomizing tank and a liquid tank, and the two tanks are connected by an outlet pipe and an inlet pipe. One end of the outlet pipe is installed at the top of the atomizing tank, and the other end is located below the liquid surface of the absorbent in the liquid tank; one end of the inlet pipe is located at the bottom of the liquid tank, and the other end is connected to an atomizing disc. The atomizing disc is located in the atomizing zone of the atomizing tank. The bottom of the atomizing tank is a liquid zone, used to seal the gas phase. A filter screen is installed on the upper part of the atomizing tank, which divides the inner cavity of the atomizing tank into an upper gas collecting zone and a middle atomizing zone. The gas collecting zone and the atomizing zone are connected through filter holes on the filter screen, and the gas collecting zone is connected to the outlet pipe. The atomizing disc includes an upper disc and a lower disc that are sealed together, forming a gas cavity between the two discs. This gas cavity is connected to an inlet pipe through an inlet, and the inlet pipe delivers high-pressure cracked gas. An inwardly protruding liquid inlet is provided at the center of the upper disc, and this liquid inlet is connected to the inlet pipe. The lower plate is a concave disc shape. The central hole of the lower plate and the outer conical surface of the liquid inlet form an exhaust ring. Auxiliary holes are evenly distributed around the circumference on the concave conical surface of the lower plate. The high-pressure gas ejected from the exhaust ring and auxiliary holes pulverizes the absorbent liquid into fine, mist-like droplets.

[0006] Furthermore, to increase the air passage cross-sectional area of ​​the filter pores, the filter screen should preferably be arc-shaped or wavy.

[0007] Furthermore, the air inlet can be located on the outer circumferential surface or the top surface of the upper plate.

[0008] Furthermore, the outer circumferential plane of the lower plate is provided with matching holes evenly distributed around the circumference. These matching holes are used for matching the gas and liquid in the atomization zone.

[0009] Furthermore, the atomizing disc is positioned at the top of the atomizing zone, with the airflow and liquid flow downwards. Alternatively, the atomizing disc is positioned at the bottom of the atomizing zone, with the airflow and liquid flow upwards.

[0010] Furthermore, the liquid tank stores absorbent liquid, and a float valve is installed at the inlet of the absorbent liquid inlet pipe to stably control the liquid level of the absorbent liquid and ensure uniform flow of absorbent liquid in the atomizing plate.

[0011] The beneficial effects of this invention are: This invention utilizes high-pressure pyrolysis gas to atomize the absorbent liquid into fine droplets, increasing the contact area between the gas and liquid phases and promoting the absorption of acidic gases by the absorbent liquid. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of Example 1;

[0013] Figure 2 This is a schematic diagram of the atomizing disc structure from the front view.

[0014] Figure 3 for Figure 2 A bottom view;

[0015] Figure 4 This is a schematic diagram of the atomizing can in Example 2;

[0016] Attached reference numerals: 1-Atomizing tank, 2-Inlet pipe, 3-Filter screen, 4-Filter holes, 5-Outlet pipe, 6-Liquid outlet pipe, 7-Liquid zone, 8-Atomizing zone, 9-Atomizing disc, 10-Gas collection zone, 11-Inlet pipe, 12-Absorbent liquid, 13-Float valve, 14-Liquid tank, 15-Exhaust pipe;

[0017] 91-Liquid inlet, 92-Upper plate, 93-Air chamber, 94-Lower plate, 95-Cutting area, 96-Air outlet ring, 97-Auxiliary hole, 98-Matching hole, 99-Air inlet. Detailed Implementation

[0018] In the accompanying drawings of this utility model, the dashed arrows indicate the direction of gas flow, and the solid arrows indicate the direction of liquid flow. Example

[0019] The structure of the acid gas absorption tank in this embodiment is shown in the attached figure. Figure 1 As shown, the device includes an atomizing tank 1 and a liquid tank 14, which are connected by an air outlet pipe 5 and a liquid inlet pipe 11. One end of the air outlet pipe 5 is installed at the top of the atomizing tank 1, and the other end is positioned below the surface of the absorbent liquid in the liquid tank. One end of the liquid inlet pipe 11 is located at the bottom of the liquid tank, and the other end is connected to the atomizing disc 9 inside the atomizing tank.

[0020] The bottom of the atomizing canister 1 is the liquid zone 7, which is connected to the liquid outlet pipe 6. A filter screen 3 is installed at the top, dividing the inner cavity into an upper gas collecting zone 10 and a middle atomizing zone 8. The gas collecting zone 10 and the atomizing zone 8 are connected through filter holes 4 on the filter screen, and the outlet pipe 5 connects to the gas collecting zone 10. To increase the air passage cross-sectional area of ​​the filter holes 4, the filter screen 3 is preferably designed as an arc or wave shape; this structure also increases the overall strength of the filter screen 3. An atomizing disc 9 is located at the top of the atomizing zone 8 of the atomizing canister, and its structure is shown in the attached figure. Figure 2 and attached Figure 3 As shown, the device includes an upper plate 92 and a lower plate 94, which are sealed together, forming an air cavity 93 between them. This air cavity 93 is connected to an air inlet pipe 2 via an air inlet 99, which can be located on the outer circumferential surface or on the top surface of the upper plate. The upper plate has an inwardly protruding liquid inlet 91 at its center, which is connected to the liquid inlet pipe 11. The lower plate is a disc-shaped structure with a concave center, the recessed area being a cutting zone 95. The center of the lower plate has a central hole, which, together with the outer conical surface of the liquid inlet, forms an air outlet ring 96. An auxiliary hole 97 is provided on the concave conical surface of the cutting zone, and a matching hole 98 is provided on the outer circumferential plane of the lower plate. The auxiliary holes 97 and the matching holes 98 are evenly distributed around the circumference.

[0021] The liquid tank 14 contains absorbent liquid 12. An absorbent liquid inlet pipe is also provided on the liquid tank, and a float valve 13 is installed at the inlet of the inlet pipe to control the liquid level of the absorbent liquid and ensure the stability of the liquid level. An exhaust pipe 15 is provided on the top of the liquid tank.

[0022] In this embodiment, during operation, the absorbent 12 in the liquid tank 14 enters the atomizing disk 9 through the inlet pipe 11 and falls from the inlet 91 on the atomizing disk. High-pressure pyrolysis gas enters the gas chamber 93 of the atomizing disk through the inlet pipe 2 and inlet 99, and is ejected at high speed from the outlet ring 96 and auxiliary hole 97. Within the cutting zone 95, the high-speed gas ejected from the outlet ring 96 pulverizes the falling absorbent into large droplets, and the high-speed gas ejected from the auxiliary hole 97 pulverizes the large droplets into fine droplets, creating an atomization effect within the atomizing zone 8. This significantly increases the contact surface area between the pyrolysis gas and the absorbent, enhancing the absorbent's absorption of acidic gases from the pyrolysis gas. The fine droplets impact the inner wall of the atomizing tank, aggregating into a liquid flow that falls by gravity to the liquid zone 7, and is then sent to the absorbent regeneration tower through the outlet pipe 6. Under pressure, the gas rises through the filter holes 4 on the filter screen and enters the gas collection zone 10. Then, it enters the absorbent liquid 12 in the liquid tank through the gas outlet pipe 5, and finally exits through the exhaust pipe 15 to proceed to the next process. The filter screen has two functions: 1) Collecting fine droplets. When gas carrying fine liquid particles passes through the filter holes 4, the droplets are adsorbed by the droplets on the filter screen, forming larger droplets, preventing a large number of droplets from entering the liquid tank and contaminating the absorbent liquid. 2) Enhancing the turbulence of the gas in the gas collection zone 10, causing fine droplets not adsorbed by the filter screen to collide and form larger droplets in the gas collection zone. These larger droplets then fall onto the filter screen under gravity and descend through the filter holes into the liquid zone. Even if a small number of fine droplets still enter the liquid tank 14 with the gas, these droplets enter the absorbent liquid and are adsorbed by it. The gas discharged through the exhaust pipe is entirely gaseous, with no liquid phase.

[0023] The function of the matching hole 98 is to increase the amount of gas in the atomization zone and achieve the ratio matching of the gas phase and the liquid phase. Under the condition that the gas supplied by the gas outlet ring 96 and the auxiliary hole 97 matches the absorbent, the matching hole 98 may not be provided.

[0024] The function of the liquid zone 7 is to seal off the atomization zone 8, prevent gas from flowing out of the liquid outlet pipe 6, and force the gas into the liquid tank 14 and out through the exhaust pipe 15. Example

[0025] In Example 1, the gas cuts the liquid downwards, and the droplets, under the influence of airflow and gravity, have a relatively short residence time in the atomization zone, which is not conducive to the absorption of the absorbent liquid. In this example, the atomizing disk 9 is placed at the bottom of the atomization zone, as shown in the attached diagram. Figure 4 As shown, the gas cuts the liquid upwards, causing the fine droplets to spray upwards and then fall under the influence of gravity. This increases the time the fine droplets spend in the atomization zone, enhancing the absorption of acidic gases by the absorbent liquid and improving the removal efficiency of acidic gases.

[0026] This invention utilizes high-pressure pyrolysis gas as the cutting power source for the absorbent, pulverizing the absorbent into fine droplets, increasing the contact area between the gas and liquid phases, and promoting the absorption of acidic gases by the absorbent. Although the partial pressure of acidic gases in the pyrolysis gas cannot remove all acidic gases, it greatly reduces the pressure of alkaline deacidification, or allows for an additional acidic gas absorption step instead of using an alkaline washing process for acid removal.

Claims

1. An acidic gas absorption vessel, characterized in that: It includes an atomizing tank and a liquid tank connected by an air outlet pipe (5) and a liquid inlet pipe (11); one end of the air outlet pipe (5) is installed on the top of the atomizing tank, and the other end is set below the liquid surface of the absorbent in the liquid tank; one end of the liquid inlet pipe (11) is set at the bottom of the liquid tank, and the other end is connected to the atomizing plate (9) in the atomizing tank. A filter screen is installed on the upper part of the atomizing can, which divides the inner cavity of the atomizing can into an upper gas collection area (10) and a middle atomizing area (8). The bottom of the atomizing can is a liquid area (7). The gas collection area (10) and the atomizing area (8) are connected through filter holes on the filter screen. The gas collection area (10) is connected to the air outlet pipe (5). An atomizing disc (9) is provided in the atomizing area (8). The atomizing disc (9) includes an upper disc (92) and a lower disc (94) that are sealed together, and an air cavity (93) is formed between the two discs. The air cavity (93) is connected to the air inlet pipe (2) through the air inlet (99). The upper disc (92) has an inwardly protruding liquid inlet (91) at its center, which is connected to the liquid inlet pipe (11). The lower disc (94) is a disc with a concave center. The central hole of the lower disc (94) and the outer conical surface of the liquid inlet (91) form an air outlet ring (96). On the concave conical surface of the lower disc (94), there are circumferentially distributed auxiliary holes (97).

2. The acidic gas absorption tank according to claim 1, characterized in that: The filter screen is arc-shaped or wavy.

3. The acidic gas absorption tank according to claim 1, characterized in that: The air inlet (99) is located on the outer circumferential surface or the top surface of the upper plate (92).

4. The acidic gas absorption tank according to claim 1, characterized in that: On the outer circumferential plane of the lower plate (94), there are matching holes (98) evenly distributed around the circumference.

5. An acidic gas absorption tank according to claim 1, characterized in that: The atomizing disc (9) is located at the top of the atomizing zone (8), with the airflow and liquid flow downwards.

6. The acidic gas absorption tank according to claim 1, characterized in that: The atomizing disc (9) is located at the bottom of the atomizing zone (8), with the airflow and liquid flow upward.

7. The acidic gas absorption tank according to claim 1, characterized in that: The liquid tank contains absorbent liquid, and a float valve is installed at the inlet of the absorbent liquid.

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