Tail gas pipe and absorption column

Abstract

The present application relates to the field of chemical tail gas emission, and specifically provides a tail gas pipe and an absorption tower containing the same, the tail gas pipe comprises a pipe body, the pipe body comprises a cylindrical pipe section and a diameter expansion pipe section arranged coaxially, the inner diameter of the diameter expansion pipe section at any position is greater than the inner diameter of the cylindrical pipe section, the pipe body further comprises a flow guide plate arranged extending inwardly from the inner wall of the diameter expansion pipe section, in the case that the flow rate of the tail gas flow is unchanged, the speed of the tail gas slows down after reaching the diameter expansion pipe section in the process of rising, the flow guide plate extending inwardly from the diameter expansion pipe section changes the flow direction of the tail gas close to the inner wall, and a turbulent flow is formed close to the center of the tail gas pipe at the end of the flow guide plate, further reducing the flow rate of the tail gas, intercepting the absorption liquid droplets entrained in the tail gas, recycling to the absorption tower, and achieving the purpose of reducing the liquid droplets entrained in the tail gas, avoiding environmental pollution.

Description

Technical Field

[0001] This invention relates to the field of chemical exhaust gas emissions, specifically to an exhaust gas pipe and an absorption tower. Background Technology

[0002] Chemical production often generates large quantities of waste gas containing various pollutants. Absorption towers are typically used to treat this waste gas, employing acid or alkali solutions for spray absorption. Due to the large volume and high temperature of the waste gas, it carries some acidic or alkaline absorbent liquid during emission. Furthermore, when the high-temperature waste gas encounters cooler air, it condenses into water droplets near the exhaust outlet. These droplets fall onto the vicinity of the absorption tower outlet, causing corrosion of surrounding equipment and posing safety and environmental hazards.

[0003] CN211514052U discloses a demisting device for an acid gas absorption tower, including a dual acid gas absorption tower and a demisting system. The demisting system uses packing interception and cooling water spraying to remove moisture entrained in the tail gas of the acid gas absorption tower. However, this method requires the addition of a spray tower, which is structurally complex, requires large investment, has many control facilities, and is not easy to operate. At the same time, the use of packing can easily lead to blockage of the absorption tower.

[0004] CN209900996U discloses a liquid collection structure for a rainproof cap on the exhaust gas of an NMP spray tower and absorption tower. By using a rainproof cap that also functions as a baffle, it intercepts some of the mist entrained in the exhaust gas, while simultaneously collecting rainwater and channeling it to the inner wall of the exhaust pipe for reuse. This reduces the mist generated by the exhaust gas, thereby reducing water consumption and energy consumption in the spray tower and absorption tower. However, this method only intercepts liquid droplets entrained in the exhaust gas through the rainproof cap, resulting in limited interception effectiveness. Furthermore, due to the small area of ​​the rainproof cap, the amount of rainwater that can be collected is limited, thus limiting its energy-saving and consumption-reducing effects. Summary of the Invention

[0005] The purpose of this invention is to overcome the problem of liquid carryover in the tail gas of the absorption tower in the prior art, and to provide a tail gas pipe and an absorption tower including the tail gas pipe. The tail gas pipe can reduce the liquid droplets entrained in the tail gas and avoid environmental pollution.

[0006] To achieve the above objectives, the present invention provides an exhaust pipe, the exhaust pipe including a pipe body, the pipe body including a cylindrical pipe section and an expanded diameter pipe section arranged coaxially, the inner diameter of any part of the expanded diameter pipe section being larger than the inner diameter of the cylindrical pipe section, and the pipe body further including a guide plate extending inward from the inner wall of the expanded diameter pipe section.

[0007] Preferably, the cross-sectional profile of the expanded pipe section includes two first arc-shaped segments that are arranged opposite to each other and protrude outwards respectively.

[0008] Preferably, the cross-sectional profile of the guide plate includes a second arc segment and a third arc segment connected together, the center of the second arc segment is located below the guide plate, the center of the third arc segment is located above the guide plate, and the end of the second arc segment away from the third arc segment is connected to the first arc segment.

[0009] Preferably, the two first arc-shaped segments are symmetrically arranged about the central axis of the tube and are circular, and this circle is denoted as the first circle C1.

[0010] Preferably, the two third arc segments are symmetrically arranged about the central axis of the tube and are circular, and this circle is denoted as the third circle C3.

[0011] Preferably, the circle containing the second arc segment is denoted as the second circle C2, the diameter of the first circle C1 is greater than the diameter of the third circle C3, and the diameter of the third circle C3 is greater than the diameter of the second circle C2.

[0012] Preferably, the exhaust pipe further includes a cover plate disposed at the top outlet end of the pipe body, and there is a radial gap between the periphery of the cover plate and the inner wall of the pipe body.

[0013] Preferably, the pipe body includes a frustum-shaped pipe section with a diameter that gradually increases toward the outlet end, located near the outlet end, and / or the cover plate includes a buffer structure for buffering the rising airflow within the pipe body.

[0014] Preferably, the cylindrical pipe section and the expanded diameter pipe section are sequentially connected below the frustum pipe section, and the projection of the cover plate on the horizontal plane covers the projection of the cylindrical pipe section on the horizontal plane; and / or the cover plate includes a plate body and a folded edge disposed on the outer periphery of the plate body, the folded edge being bent downward to form an angle with the plate body that opens downward to form the buffer structure.

[0015] Preferably, a conical protrusion is formed downward along the central axis of the cylindrical tube section in the middle of the plate.

[0016] Another aspect of the present invention provides an absorption tower, including the aforementioned exhaust pipe.

[0017] It is easy to see from the above technical solution that the advantages of the present invention are:

[0018] When the exhaust gas flow rate remains constant, the exhaust gas slows down after reaching the expansion pipe section during its ascent. In conjunction with the guide plate extending inward from the expansion pipe section, the flow direction of the exhaust gas close to the inner wall is changed, and turbulence is formed at the end of the guide plate near the center of the exhaust pipe, further reducing the exhaust gas velocity and intercepting the absorbent droplets entrained in the exhaust gas, which are then recovered to the absorption tower. This achieves the purpose of reducing the droplets entrained in the exhaust gas and avoiding environmental pollution. Attached Figure Description

[0019] Figure 1 This is a cross-sectional schematic diagram of one embodiment of the exhaust pipe in this invention;

[0020] Figure 2 yes Figure 1 Enlarged view of point A;

[0021] Figure 3 It shows Figure 1 The direction of exhaust gas flow in the exhaust pipe.

[0022] Explanation of reference numerals in the attached figures

[0023] 1. Cylindrical pipe section;

[0024] 2. Expanded diameter pipe section;

[0025] 201 First arc segment;

[0026] 3. Deflectors;

[0027] 301 Second arc segment; 302 Third arc segment;

[0028] 4. Cover plate;

[0029] 401 Panel; 402 Folded Edge; 403 Connector;

[0030] 5 frustum-shaped pipe sections;

[0031] C1 is the first circle; C2 is the second circle; C3 is the third circle. Detailed Implementation

[0032] To make the technical solutions and advantages of the embodiments of the present invention clearer, the exemplary embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not an exhaustive list of all embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0033] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship commonly used when the product is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0034] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0035] An absorption tower is a device used for absorption operations. The absorbent is added from the top of the tower and flows downwards, contacting the gas flowing upwards. The liquid that has absorbed the absorbent is discharged from the bottom of the tower, and the purified gas is discharged from the top of the tower.

[0036] In existing technologies, the exhaust gas from absorption towers is prone to carrying acidic or alkaline absorption liquids, leading to environmental pollution.

[0037] In view of the above-mentioned problems, the present invention provides an exhaust pipe, which includes a pipe body, and the pipe body includes a cylindrical pipe section 1 and an expanded diameter pipe section 2 arranged coaxially. The inner diameter of any part of the expanded diameter pipe section 2 is larger than the inner diameter of the cylindrical pipe section 1. The pipe body also includes a guide plate 3 extending inward from the inner wall of the expanded diameter pipe section 2.

[0038] In this invention, the inner diameter of the expanded pipe section 2 is larger than the inner diameter of the cylindrical pipe section 1, and the exhaust gas flow at point a (reference) Figure 3 With the flow rate remaining constant, the exhaust gas slows down after reaching the expansion pipe section 2 during its ascent. In conjunction with the guide plate 3 extending inward from the expansion pipe section 2, the flow direction of the exhaust gas close to the inner wall is changed, and turbulence is formed at the end of the guide plate 3 near the center of the exhaust pipe, further reducing the exhaust gas velocity and intercepting the absorbent droplets entrained in the exhaust gas, which are then recovered to the absorption tower. This achieves the purpose of reducing the droplets entrained in the exhaust gas and avoiding environmental pollution.

[0039] It is worth noting that, in this invention, the pipe body may include multiple cylindrical pipe sections 1 and at least one expanded diameter pipe section 2, that is, there may be multiple expanded diameter pipe sections 2. These expanded diameter pipe sections 2 may be arranged continuously, similar to an arrangement of "cylindrical pipe section 1 - expanded diameter pipe section 2 - expanded diameter pipe section 2 - expanded diameter pipe section 2 - cylindrical pipe section 1"; the expanded diameter pipe section 2 may also be arranged offset from the cylindrical pipe section 1, similar to an arrangement of "cylindrical pipe section 1 - expanded diameter pipe section 2 - cylindrical pipe section 1 - expanded diameter pipe section 2 - cylindrical pipe section 1"; or a partially offset and partially continuous arrangement, similar to an arrangement of "cylindrical pipe section 1 - expanded diameter pipe section 2 - expanded diameter pipe section 2 - cylindrical pipe section 1 - expanded diameter pipe section 2". This invention does not limit this arrangement.

[0040] The specific structure of the expanded diameter pipe section 2 is not required. For example, the shape of its horizontal cross section can be circular or polygonal, and its inner diameter can be larger than that of the cylindrical pipe section 1.

[0041] The specific structure of the guide vane 3 is not required. For example, it can extend inward and upward, horizontally, or inward and downward; it can extend in a straight line or in a wavy shape. Its purpose is to create turbulence in the exhaust gas near the center of the exhaust pipe at the end of the guide vane 3, reducing the exhaust gas velocity and intercepting liquid droplets entrained in the exhaust gas. Understandably, when the end of the guide vane 3 extends inward and downward, the exhaust gas flows in the opposite direction to the normally rising exhaust gas flow at the bottom of the pipe, maximizing the reduction of exhaust gas velocity and creating turbulence. Correspondingly, the effect of removing liquid droplets entrained in the exhaust gas is also the best.

[0042] In some implementation methods, please refer to Figure 1 and Figure 2 The cross-sectional profile of the expanded diameter pipe section 2 includes two first arc-shaped sections 201 that are arranged opposite to each other and protrude outwards respectively.

[0043] The design of the first arc-shaped section 201 allows the exhaust gas to flow more smoothly in the expansion pipe section 2, avoiding unnecessary airflow fluctuations. The first arc-shaped section 201 protrudes in a direction away from the axis of the expansion pipe section 2, which ensures that the inner diameter of the expansion pipe section 2 is larger than the inner diameter of the cylindrical pipe section 1.

[0044] Understandably, when the expanded diameter pipe sections 2 are arranged continuously, the end of the first arc-shaped section 201 is connected to another first arc-shaped section 201; when the expanded diameter pipe sections 2 and the cylindrical pipe sections 1 are arranged in a staggered manner, the end of the first arc-shaped section 201 is connected to the cylindrical pipe section 1.

[0045] Furthermore, in the above embodiments, please refer to Figure 2 The cross-sectional profile of the guide plate 3 includes a second arc segment 301 and a third arc segment 302 connected together. The center of the arc of the second arc segment 301 is located below the guide plate 3, and the center of the arc of the third arc segment 302 is located above the guide plate 3. The end of the second arc segment 301 away from the third arc segment 302 is connected to the first arc segment 201.

[0046] The second arc segment 301 with its center at the bottom can perfectly withstand the exhaust gas flow from the first arc segment 201, making the overall airflow smooth. The third arc segment 302 with its center at the top guides the exhaust gas flow to the central axis of the pipe, causing the airflow to converge and form turbulence, which is convenient for removing liquid droplets entrained in the exhaust gas.

[0047] Furthermore, in the above embodiments, please refer to Figure 1 and Figure 2The two first arc segments 201 are symmetrically arranged about the central axis of the tube and are concentric circles, which are denoted as the first circle C1.

[0048] Clearly, when the curvature of the first arc segment 201 relative to the cylindrical pipe segment 1 is too small, the airflow deceleration effect is small; when the curvature of the first arc segment 201 relative to the cylindrical pipe segment 1 is too large, the airflow is prone to turbulence in the expansion pipe segment 2 and is difficult to converge at the end of the guide plate 3 according to the preset direction of travel. Therefore, when the two first arc segments 201 symmetrical about the central axis of the pipe body are concentric, the curvature of the first arc segment 201 is more appropriate, which can ensure the airflow deceleration effect without causing the airflow to become directly turbulent when entering the expansion pipe segment 2.

[0049] Furthermore, in the above embodiments, please refer to Figure 1 and Figure 2 The two third arc segments 302 are symmetrically arranged about the central axis of the tube and are circular. This circle is denoted as the third circle C3.

[0050] Understandably, when the two third arc segments 302 are concentric, the exhaust gas flow can be ultimately directed to the intersection of the tangents that are tangent to the two third arc segments 302 respectively. At the same time, the droplets collected above the expansion pipe section 2 fall onto the third arc segment 302 and can slide naturally along the circumference of the third circle C3, reducing the direct impact of the droplets on the guide plate 3, achieving two goals at once.

[0051] Furthermore, in the above embodiments, please refer to Figure 1 and Figure 2 The circle containing the second arc segment 301 is denoted as the second circle C2. The diameter of the first circle C1 is greater than the diameter of the third circle C3, which is greater than the diameter of the second circle C2.

[0052] Understandably, the second circle C2 has the smallest diameter, which facilitates the rapid guidance of the exhaust gas flow to the third arc segment 302. The first circle C1 has the largest diameter, which ensures the deceleration and stability of the overall airflow. The diameter of the third circle C3 is between that of the first circle C1 and the second circle C2, and it mainly plays the role of guiding the exhaust gas flow to finally converge and the buffer droplets to fall.

[0053] In some implementation methods, please refer to Figure 1 The exhaust pipe also includes a cover plate 4 located at the top outlet end of the pipe body, with a radial gap between the periphery of the cover plate 4 and the inner wall of the pipe body. That is, referring to... Figure 1 The bottom of the pipe is the inlet end, and the top of the pipe is the outlet end.

[0054] Cover plate 4 is set at the top of the pipe body, such as Figure 3 As shown, the airflow at point b is obstructed by the cover plate 4, forming turbulence and reducing the exhaust gas velocity. This causes the exhaust gas to eventually converge in the radial gap and escape, which can further intercept the absorbent liquid droplets entrained in the exhaust gas.

[0055] It should be noted that the shape and structure of the cover plate 4 are not required. For example, the cover plate 4 can be circular, square or irregular in shape.

[0056] Similarly, the connection method between the cover plate 4 and the pipe body is not required. For example, the cover plate 4 can be directly connected to the inner wall of the pipe body via the connector 403 (e.g., Figure 1 (As shown), it can also be suspended at the top of the pipe opening by a fixing device (not shown).

[0057] In some implementations, please refer to [the documentation / reference]. Figure 1 The pipe body includes a frustum-shaped pipe section 5 with a diameter that gradually increases toward the outlet end, located near the outlet end.

[0058] It is worth noting that the inclination method of the frustum-shaped tube segment 5 is not required. For example, the top of the cylindrical tube segment 1 can be inclined linearly (e.g., ...). Figure 1 (as shown), or it can be tilted along an arc (not shown).

[0059] Furthermore, in the above embodiment, the cylindrical pipe section 1 and the expanded diameter pipe section 2 are connected sequentially below the frustum pipe section 5, and the projection of the cover plate 4 on the horizontal plane covers the projection of the cylindrical pipe section 1 on the horizontal plane.

[0060] In other words, the cover plate 4 can completely block the exhaust gas flow inside the cylindrical pipe section 1, forcing the exhaust gas flow to decelerate and converge from the radial gap around the cover plate 4 and escape. At this time, the effect of intercepting the absorbent liquid droplets entrained in the exhaust gas is also the best.

[0061] Furthermore, in the above embodiments, please refer to Figure 1 The cover plate 4 includes a buffer structure for buffering the rising airflow inside the pipe.

[0062] Understandably, the high-speed upward flow of exhaust gas is obstructed at the cover plate 4, forming turbulence. The downward-opening buffer structure can prevent the exhaust gas flow from impacting the cover plate 4 for a long time and guide the exhaust gas flow to the periphery of the cover plate 4, thus improving the durability of the cover plate 4.

[0063] The present invention does not require the specific structure of the buffer structure; its cross-section can be an isosceles triangle, a semicircle, or other shapes.

[0064] Specifically, in the above embodiment, the cover plate 4 includes a plate body 401 and a folded edge 402 disposed on the outer periphery of the plate body 401. The folded edge 402 is bent downward to form an angle with the plate body 401 with the opening facing downward to form a buffer structure.

[0065] Understandably, the downward-opening buffer structure formed between the plate 401 and the folded edge 402 can buffer the exhaust gas flow.

[0066] It should be noted that the plate 401 and the folded edge 402 here can be linear bends (such as...). Figure 1 (As shown), it can also be an arc bend, but this invention does not require it to be.

[0067] Furthermore, in the above embodiments, please refer to Figure 1 A conical protrusion is formed in the middle of plate 401 along the central axis of cylindrical tube section 1.

[0068] The conical protrusion can divert the central part of the exhaust gas flow outward, allowing it to escape into the radial gaps around the cover plate. At the same time, the conical protrusion has a better buffering effect on the rising exhaust gas flow compared to other shapes.

[0069] The present invention also provides an absorption tower, which includes the above-mentioned exhaust pipe. It is understood that the beneficial effects that the exhaust pipe can achieve can also be achieved by the absorption tower, so it will not be described in detail here.

[0070] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from the spirit and scope of this invention. Therefore, if these modifications and variations of this invention fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. An exhaust pipe, characterized in that, The exhaust pipe includes a pipe body, which includes a coaxially arranged cylindrical pipe section (1) and an expanded diameter pipe section (2). The inner diameter of any part of the expanded diameter pipe section (2) is larger than the inner diameter of the cylindrical pipe section (1). The pipe body also includes a guide plate (3) extending inward from the inner wall of the expanded diameter pipe section (2). The cross-sectional profile of the expanded pipe section (2) includes two first arc-shaped sections (201) that are arranged opposite to each other and protrude outwards respectively. The cross-sectional profile of the guide plate (3) includes a connected second arc segment (301) and a third arc segment (302). The center of the arc of the second arc segment (301) is located below the guide plate (3), and the center of the arc of the third arc segment (302) is located above the guide plate (3). The end of the second arc segment (301) away from the third arc segment (302) is connected to the first arc segment (201). The two first arc segments (201) are symmetrically arranged about the central axis of the tube and are circular, which is denoted as the first circle (C1). The two third arc segments (302) are symmetrically arranged about the central axis of the tube and are circular, which is denoted as the third circle (C3). The circle containing the second arc segment (301) is denoted as the second circle (C2). The diameter of the first circle (C1) is greater than the diameter of the third circle (C3), and the diameter of the third circle (C3) is greater than the diameter of the second circle (C2).

2. The exhaust pipe according to claim 1, characterized in that, The exhaust pipe also includes a cover plate (4) disposed at the top outlet end of the pipe body, and there is a radial gap between the periphery of the cover plate (4) and the inner wall of the pipe body.

3. The exhaust pipe according to claim 2, characterized in that, The pipe body includes a frustum-shaped pipe section (5) with a diameter that gradually increases toward the outlet end, located near the outlet end, and / or The cover plate (4) includes a buffer structure for buffering the rising airflow inside the pipe.

4. The exhaust pipe according to claim 3, characterized in that, The cylindrical pipe section (1) and the expanded diameter pipe section (2) are connected sequentially below the frustum pipe section (5), and the projection of the cover plate (4) on the horizontal plane covers the projection of the cylindrical pipe section (1) on the horizontal plane; and / or The cover plate (4) includes a plate body (401) and a flange (402) disposed on the outer periphery of the plate body (401). The flange (402) is bent downward to form an angle with the plate body (401) with the opening facing downward to form the buffer structure.

5. The exhaust pipe according to claim 4, characterized in that, A conical protrusion is formed in the middle of the plate (401) along the central axis of the cylindrical tube section (1).

6. An absorption tower, characterized in that, Includes the exhaust pipe as described in any one of claims 1-5.

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