A dimethyl ether rectification column device

Abstract

This application discloses a dimethyl ether distillation column apparatus, relating to the field of distillation equipment. It includes a column body and packing. The inner wall of the column body has a flow-blocking transition surface corresponding to the position of the packing. The flow-blocking transition surface contacts the packing and has flow-blocking protrusions extending circumferentially along the column body. Multiple sets of flow-blocking protrusions are arranged at intervals along the height direction of the column body. Each set of flow-blocking protrusions has multiple channels, equidistantly arranged circumferentially along the column body. Two adjacent sets of flow-blocking protrusions are staggered circumferentially along the column body. In two adjacent sets of flow-blocking protrusions, the opposite ends of the two adjacent upper flow-blocking protrusions are simultaneously located above one of the lower flow-blocking protrusions. This application reduces the adverse effects of wall flow on distillation efficiency by decreasing the downward flow velocity of the wall flow and increasing the probability of liquid reflux back to the packing.

Description

Technical Field

[0001] This application relates to the field of distillation equipment, and in particular to a dimethyl ether distillation column apparatus. Background Technology

[0002] Dimethyl ether is an organic compound that is a colorless, odorous, and flammable gas under standard conditions. It is primarily used as a methylating agent in the production of dimethyl sulfate, acetic anhydride, and ethylene. It can also be used as an alkylating agent, refrigerant, leaching agent, extractant, and anesthetic, among other applications. Industrially, dimethyl ether is commonly produced using a methanol vapor-phase dehydration process. This process can be divided into several steps: methanol vaporization, dehydration reaction, product separation, distillation, and tail gas treatment.

[0003] In the dimethyl ether distillation process, the dimethyl ether column operates under specific pressure and temperature conditions (dimethyl ether has a boiling point of -24.84 °C at standard atmospheric pressure, requiring relatively high operating pressure for liquefaction). Based on the different boiling points of dimethyl ether, methanol, and water, the process separates the methanol reaction products into different "fractions," i.e., separating the reaction products into gaseous products (dimethyl ether, etc.), liquid methanol, and wastewater. Through mass and heat transfer in the packed column equipment, dimethyl ether and other trace gases in methanol and wastewater are continuously separated and distilled.

[0004] Dimethyl ether distillation typically employs packed columns. The gaps between the packing and the column wall result in a significantly higher porosity in the wall region compared to the central packing area, creating low-resistance channels. Under gravity, the liquid preferentially flows towards the lower-resistance wall region, forming wall flow. In randomly packed packing, the liquid tends to diverge outwards as it flows downwards due to the random arrangement of the packing. Once it contacts the column wall, it flows continuously down the wall, losing its random distribution characteristics. The increased liquid flow rate in the wall region and the resulting dry zone in the central region significantly reduce the gas-liquid two-phase contact area, leading to decreased mass transfer efficiency. Furthermore, the high-speed gas-liquid two-phase flow during distillation increases erosion of the column wall. Summary of the Invention

[0005] To reduce the adverse effects of wall flow during the dimethyl ether distillation process, this application provides a dimethyl ether distillation column apparatus.

[0006] The dimethyl ether distillation column apparatus provided in this application adopts the following technical solution: A dimethyl ether distillation column apparatus includes a column body and packing. A flow-blocking transition surface is provided on the inner wall of the column body corresponding to the position of the packing. The flow-blocking transition surface contacts the packing and is provided with flow-blocking protrusions. The flow-blocking protrusions extend circumferentially along the column body. Multiple sets of flow-blocking protrusions are provided and spaced apart along the height direction of the column body. Each set of flow-blocking protrusions has multiple channels, which are equidistantly arranged circumferentially along the column body. Two adjacent sets of flow-blocking protrusions are staggered circumferentially along the column body. In two adjacent sets of flow-blocking protrusions, the opposite ends of the two adjacent upper flow-blocking protrusions are simultaneously located above one of the lower flow-blocking protrusions.

[0007] By adopting the above technical solution, an annular gap is formed between the inner wall of the column and the packing. As the liquid inside the packing flows downwards under gravity, it preferentially flows into the annular gap between the inner wall of the column and the packing, forming wall flow along the inner wall of the column. By setting a flow-blocking transition surface on the inner wall of the column corresponding to the packing position, the flow-blocking protrusions of the transition surface impede the liquid flowing along the inner wall of the column, which helps to reduce the downward flow velocity of the liquid along the inner wall of the column. Furthermore, the flow-blocking protrusions allow for a tighter contact with the packing, making it easier for the liquid to flow towards the packing when passing through the protrusions. By reducing the downward flow velocity of the wall flow and increasing the probability of the wall flow liquid returning to the packing, the liquid flowing along the inner wall of the column has a greater chance of returning to the gaps in the packing, thereby reducing the adverse effects of wall flow on distillation efficiency.

[0008] Optionally, the inner side of the tower body is provided with a receiving cylinder, which encloses the packing material. The receiving cylinder is sealed to the inner peripheral wall of the tower body, and the inner wall of the receiving cylinder serves as a flow-blocking transition surface. The receiving cylinder is a sheet metal structural component, and the flow-blocking ridges are formed by stamping, with concave patterns formed on the back of the flow-blocking ridges.

[0009] By adopting the above technical solution, the inner wall of the sheet metal container cylinder can be used as a flow-blocking transition surface, which can reduce the processing difficulty of the flow-blocking convex pattern.

[0010] Optionally, the tower body is provided with a support structure for supporting the packing material, the tower body is provided with a collection pipe, the edge of the pipe opening of the collection pipe intersects with the support surface of the support structure, and the collection pipe is provided with a gas-liquid separator.

[0011] By adopting the above technical solution, when the distillation feedstock enters the space between the cylinder wall and the inner wall of the column in gaseous form and condenses into liquid, the liquid between the cylinder wall and the inner wall of the column can be discharged through the collection pipe. A gas-liquid separator is installed on the collection pipe to reduce leakage of the feedstock in gaseous form.

[0012] Optionally, the receiving cylinder is provided with an upper end plate and a lower end plate, both of which are annular structures. The upper end plate and the lower end plate are located on the periphery of the receiving cylinder. A sealing edge is connected to the outer peripheral edge of the upper end plate. The sealing edge is located above the upper end plate and abuts against the inner wall of the tower body.

[0013] By adopting the above technical solution, and by setting an upper end plate and a lower end plate on the receiving cylinder, a gap can be formed between the cylinder wall and the inner wall of the tower. Since the receiving cylinder is a sheet metal structure, it has elastic deformation capability, enabling the receiving cylinder to form a tighter contact with the packing under the action of elastic deformation force.

[0014] Optionally, the receiving cylinder is provided with an expansion joint that runs vertically through the cylinder, and a sealing strip is provided inside the expansion joint of the receiving cylinder.

[0015] By adopting the above technical solution, the expansion joint of the receiving cylinder can expand and contract by compressing the sealing strip, causing the circumference of the receiving cylinder to expand and contract, thus resulting in a slight change in the diameter of the receiving cylinder. Therefore, when the receiving cylinder is installed into the tower body from top to bottom, it can contract under the compression of the tower body, which helps to reduce the frictional resistance between the receiving cylinder and the tower body, thereby reducing the difficulty of installing the receiving cylinder.

[0016] Optionally, two sealing strips are provided and arranged side by side along the width direction of the expansion joint, with a long strip gasket inserted between the two sealing strips.

[0017] By adopting the above technical solution, during the process of hoisting the container into the inside of the tower, the long strip gasket is pre-extracted from between the two sealing strips, allowing for a greater range of expansion and contraction in the expansion joint of the container. After the container is installed in place, the long strip gasket is then inserted between the two sealing strips to further widen the expansion joint of the container, ensuring that the container is pressed tightly against the inner wall of the tower.

[0018] Optionally, the sealing strip is made of rubber, and a polytetrafluoroethylene (PTFE) lubricating layer is provided on the opposite sides of the two sealing strips. The two sides of the elongated gasket respectively abut against the two PTFE lubricating layers.

[0019] By adopting the above technical solution and setting a polytetrafluoroethylene lubricating layer on the opposite sides of the two sealing strips, the resistance that the long strip gasket needs to overcome when inserted between the two sealing strips can be reduced.

[0020] Optionally, the inner circumferential surface of the receiving cylinder is set as a conical surface, and the inner diameter of the receiving cylinder gradually increases from top to bottom.

[0021] By adopting the above technical solution, the inner circumferential surface of the container is set as a conical surface, and the inner diameter of the container gradually increases from top to bottom, so that the inner circumferential surface of the container is inclined downward, making it difficult for the liquid to flow downward along the inner wall of the container, thereby further reducing the phenomenon of wall flow.

[0022] Optionally, a packing support plate is detachably connected to the lower end of the container, and a hoisting structure is provided at the upper end of the container.

[0023] By adopting the above technical solution, the packing support plate and the receiving cylinder can be detachably connected as a whole, so that the receiving cylinder, packing support plate and packing can be pre-assembled as a whole and then hoisted into the tower body, making the operation faster.

[0024] Optionally, an elastic buffer is provided between the packing support plate and the lower end of the receiving cylinder; the elastic buffer is a sheet metal part and has an overall annular groove structure, with the annular groove opening of the elastic buffer facing downwards, and the inner and outer sidewalls of the elastic buffer gradually moving away from each other from top to bottom.

[0025] By adopting the above technical solution and setting an elastic buffer, the distance between the packing support plate and the upper end plate of the container can be adjusted by a small range. Since the inner circumferential surface of the container is set as a downward conical surface, when the distance between the packing support plate and the upper end plate decreases, the inner circumferential surface of the container can squeeze the packing, making the contact between the packing and the inner wall of the container more compact.

[0026] In summary, this application includes at least one of the following beneficial technical effects: By setting a flow-blocking transition surface on the inner wall of the column corresponding to the packing, the flow-blocking protrusions of the transition surface obstruct the liquid flowing along the inner wall of the column, which helps to reduce the speed at which the liquid flows down the inner wall of the column. Moreover, the flow-blocking protrusions can make a tighter contact with the packing, and when the liquid flows through the flow-blocking protrusions, it is easier to flow towards the packing; thus reducing the adverse effects of wall flow on distillation efficiency. By using the inner wall of the sheet metal container as a flow-blocking transition surface, the processing difficulty of the flow-blocking embossing can be reduced. When the distillation feedstock enters the space between the cylinder wall and the inner wall of the column in gaseous form and condenses into liquid, the liquid between the cylinder wall and the inner wall of the column can be discharged through the collection pipe. A gas-liquid separator is installed on the collection pipe to reduce leakage of the feedstock in gaseous form. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the dimethyl ether distillation column apparatus of Example 1.

[0028] Figure 2 This is a schematic diagram of the structure of the container cylinder in Example 1.

[0029] Figure 3 This is a schematic diagram of the structure of the container cylinder in Example 2.

[0030] Figure 4 yes Figure 3 A magnified view of point A in the middle.

[0031] Figure 5 This is a schematic diagram of the structure of the container cylinder in Example 3.

[0032] Figure 6 yes Figure 5 A magnified view of point B in the middle.

[0033] Explanation of reference numerals in the attached figures: 1. Tower body; 2. Packing; 3. Support structure; 4. Container cylinder; 41. Flow-blocking raised texture; 42. Concave texture; 43. Upper end plate; 44. Lower end plate; 45. Sealing edge; 46. Expansion joint; 47. Sealing strip; 471. Long strip gasket; 472. PTFE lubricating layer; 48. Side plate; 5. Collection pipe; 6. Gas-liquid separator; 7. Support plate; 8. Elastic buffer; 9. Bolt and nut assembly; 10. Lifting structure. Detailed Implementation

[0034] The following is in conjunction with the appendix Figure 1-6 This application will be described in further detail. Example 1

[0035] This application discloses a dimethyl ether distillation column apparatus. (Refer to...) Figure 1 The dimethyl ether distillation column device includes a column body 1 and packing 2. In this embodiment, the packing 2 is a structured packing 2. The inner wall of the column body 1 is fixedly provided with a support structure 3 for supporting the packing 2. The support structure 3 is a grid structure.

[0036] Reference Figure 1 and Figure 2 A receiving cylinder 4 is provided on the inner side of the tower body 1 corresponding to the position of the packing 2. The receiving cylinder 4 is a sheet metal structural component. The receiving cylinder 4 encloses the packing 2 and is sealed to the inner circumferential wall of the tower body 1. The inner wall of the receiving cylinder 4 serves as a flow-blocking transition surface, which contacts the packing 2. The flow-blocking transition surface is provided with flow-blocking protrusions 41, which are formed by stamping. The back of the flow-blocking protrusions 41 forms concave grooves 42. The flow-blocking protrusions 41 extend circumferentially along the receiving cylinder 4. Multiple sets of flow-blocking protrusions 41 are provided and are spaced apart along the height direction of the receiving cylinder 4. Each set of flow-blocking protrusions 41 has multiple protrusions and is equidistantly arranged along the circumferential direction of the receiving cylinder 4. Two adjacent sets of flow-blocking protrusions 41 are staggered along the circumferential direction of the receiving cylinder 4. In two adjacent sets of flow-blocking protrusions 41, the opposite ends of the two adjacent upper flow-blocking protrusions 41 are simultaneously located above the lower flow-blocking protrusion 41.

[0037] Reference Figure 1The tower body 1 is equipped with a collection pipe 5. The edge of the collection pipe 5, which connects to the tower body 1, intersects with the support surface of the support structure 3. The collection pipe 5 is equipped with a gas-liquid separator 6. Liquid between the wall of the receiving cylinder 4 and the inner wall of the tower body 1 can be discharged through the collection pipe 5. The gas-liquid separator 6 on the collection pipe 5 can reduce the leakage of raw materials in a gaseous state. The liquid collected by the collection pipe 5 can be diverted to the bottom of the tower body 1 or collected and treated separately.

[0038] The implementation principle of the dimethyl ether distillation column apparatus in this application embodiment is as follows: An annular gap is formed between the inner wall of the column body 1 and the packing 2. During the downward flow of liquid inside the packing 2 under the action of gravity, it preferentially flows into the annular gap between the inner wall of the column body 1 and the packing 2, forming wall flow along the inner wall of the column body 1. By setting a flow-blocking transition surface at the position corresponding to the packing 2 on the inner wall of the column body 1, the flow-blocking protrusions 41 of the flow-blocking transition surface obstruct the liquid flowing along the inner wall of the column body 1, which helps to reduce the downward flow velocity of the liquid along the inner wall of the column body 1. Moreover, the flow-blocking protrusions 41 can make closer contact with the packing 2, and when the liquid flows through the flow-blocking protrusions 41, it is easier for it to flow towards the packing 2. By reducing the downward flow velocity of the wall flow and increasing the probability of the wall flow liquid returning to the packing 2, the liquid flowing along the inner wall of the column body 1 has a greater probability of returning to the gap in the packing 2, thereby reducing the adverse effect of wall flow on distillation efficiency. Example 2

[0039] Reference Figure 3 and Figure 4 The difference between this embodiment and embodiment 1 is that in this embodiment, the receiving cylinder 4 is provided with an upper end plate 43 and a lower end plate 44. Both the upper end plate 43 and the lower end plate 44 are annular structures and planar structures, and are perpendicular to the center line of the receiving cylinder 4. The inner edge of the upper end plate 43 is welded and fixed to the upper edge of the receiving cylinder 4, and the inner edge of the lower end plate 44 is welded and fixed to the lower edge of the receiving cylinder 4. Both the upper end plate 43 and the lower end plate 44 are located on the periphery of the receiving cylinder 4. A sealing edge 45 is welded and connected to the outer peripheral edge of the upper end plate 43. The sealing edge 45 is a bent structure and is located above the upper end plate 43. The sealing edge 45 abuts against the inner wall of the tower body 1.

[0040] By providing an upper end plate 43 and a lower end plate 44 on the receiving cylinder 4, a gap can be formed between the cylinder wall of the receiving cylinder 4 and the inner wall of the tower body 1. Since the receiving cylinder 4 is a sheet metal structural component, it has elastic deformation capability, which allows the receiving cylinder 4 to form a tighter contact with the packing 2 under the action of elastic deformation force.

[0041] The receiving cylinder 4 has a vertically extending expansion joint 46. Side plates 48 are welded and fixed to both sides of the receiving cylinder 4 corresponding to the expansion joint 46. The extension surface of the side plates 48 is arranged radially along the receiving cylinder 4. The expansion joint 46 simultaneously passes through the upper end plate 43, the lower end plate 44, and the sealing edge 45. A sealing strip 47 is filled inside the expansion joint 46 of the receiving cylinder 4. Two sealing strips 47 are provided. The sealing strips 47 are made of rubber and are arranged side-by-side along the width direction of the expansion joint 46. The two sealing strips 47 are respectively bonded and fixed to the two side plates 48. A long strip gasket 471 is inserted between the two sealing strips 47. A polytetrafluoroethylene (PTFE) lubricating layer 472 is provided on the opposite sides of the two sealing strips 47. The two sides of the long strip gasket 471 abut against the two PTFE lubricating layers 472 respectively.

[0042] During the process of hoisting the receiving cylinder 4 into the inner side of the tower body 1, the long strip gasket 471 is pre-extracted from between the two sealing strips 47 to allow for a greater range of expansion and contraction of the expansion joint 46 of the receiving cylinder 4. After the receiving cylinder 4 is installed in place, the long strip gasket 471 is then inserted between the two sealing strips 47 to further expand the expansion joint 46 of the receiving cylinder 4, so that the receiving cylinder 4 is pressed tightly against the inner wall of the tower body 1. Example 3

[0043] Reference Figure 5 and Figure 6 The difference between this embodiment and Embodiment 2 is that the inner circumferential surface of the receiving cylinder 4 is set as a conical surface, and the inner diameter of the receiving cylinder 4 gradually increases from top to bottom. The inner circumferential surface of the receiving cylinder 4 is set as a downward-facing conical surface, which makes it difficult for the liquid to flow downward along the inner wall of the receiving cylinder 4, and helps to further reduce the phenomenon of wall flow.

[0044] In this embodiment, the lower end of the receiving cylinder 4 is provided with a packing 2 support plate 7 and an elastic buffer 8. The packing 2 support plate 7 has evenly distributed holes, and the elastic buffer 8 is located between the packing 2 support plate 7 and the lower end plate 44. The elastic buffer 8 is a sheet metal part and has an overall annular groove structure. The annular groove opening of the elastic buffer 8 faces downward, and the inner and outer sidewalls of the elastic buffer 8 gradually move away from each other from top to bottom. The packing 2 support plate 7 and the lower end plate 44 are connected by a bolt and nut assembly 9, and the bolts of the bolt and nut assembly 9 pass through the bottom wall of the annular groove of the elastic buffer 8. Both the packing 2 support plate 7 and the support structure 3 have holes for avoiding the bolt and nut assembly 9.

[0045] The upper end of the container cylinder 4 is provided with a lifting structure 10, which is a lifting ring or a lifting hook.

[0046] In this embodiment, the packing 2 support plate 7 and the receiving cylinder 4 are connected as a whole by bolt and nut assembly 9. An elastic buffer 8 is provided between the lower end plate 44 and the packing 2 support plate 7, allowing for slight adjustment of the distance between the packing 2 support plate 7 and the upper end plate 43 of the receiving cylinder 4. Since the inner circumferential surface of the receiving cylinder 4 is set as a downward conical surface, when the distance between the packing 2 support plate 7 and the upper end plate 43 decreases, the inner circumferential surface of the receiving cylinder 4 can compress the packing 2, making the contact between the packing 2 and the inner wall of the receiving cylinder 4 more compact. After the receiving cylinder 4, the packing 2 support plate 7, and the packing 2 are pre-assembled as a whole, they are hoisted into the tower body 1 using the hoisting structure 10, making the operation faster.

[0047] It is worth mentioning that in this embodiment, the sealing strip 47 inside the expansion joint 46 is set as a single unit, and there is no need to set the long strip gasket 471 and the polytetrafluoroethylene lubricating layer 472.

[0048] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A dimethyl ether distillation column apparatus, characterized in that: The tower body (1) and packing (2) are included. The inner wall of the tower body (1) is provided with a flow-blocking transition surface corresponding to the position of the packing (2). The flow-blocking transition surface is in contact with the packing (2). The flow-blocking transition surface is provided with flow-blocking ridges (41). The flow-blocking ridges (41) extend along the circumference of the tower body (1). There are multiple sets of flow-blocking ridges (41) and they are spaced apart along the height direction of the tower body (1). Each set of flow-blocking ridges (41) is provided with multiple ridges and they are arranged at equal intervals along the circumference of the tower body (1). Two adjacent sets of flow-blocking ridges (41) are staggered along the circumference of the tower body (1). In the two adjacent sets of flow-blocking ridges (41), the opposite ends of the two adjacent flow-blocking ridges (41) at the top are simultaneously located above the flow-blocking ridge (41) at the bottom.

2. The dimethyl ether distillation column apparatus according to claim 1, characterized in that: The inner side of the tower body (1) is provided with a receiving cylinder (4), which encloses the packing (2). The receiving cylinder (4) is sealed to the inner circumferential wall of the tower body (1). The inner wall of the receiving cylinder (4) serves as a flow-blocking transition surface. The receiving cylinder (4) is a sheet metal structural component. The flow-blocking ridge (41) is formed by stamping. The back of the flow-blocking ridge (41) forms a concave ridge (42).

3. The dimethyl ether distillation column apparatus according to claim 2, characterized in that: The tower body (1) is provided with a support structure (3) for supporting the packing (2), the tower body (1) is provided with a collection pipe (5), the edge of the pipe opening of the collection pipe (5) intersects with the support surface of the support structure (3), and the collection pipe (5) is provided with a gas-liquid separator (6).

4. The dimethyl ether distillation column apparatus according to claim 2, characterized in that: The receiving cylinder (4) is provided with an upper end plate (43) and a lower end plate (44). Both the upper end plate (43) and the lower end plate (44) are annular structures. Both the upper end plate (43) and the lower end plate (44) are located on the periphery of the receiving cylinder (4). The outer peripheral edge of the upper end plate (43) is connected to a sealing edge (45). The sealing edge (45) is located above the upper end plate (43) and abuts against the inner wall of the tower body (1).

5. The dimethyl ether distillation column apparatus according to claim 2, characterized in that: The container (4) is provided with an expansion joint (46) that runs through the top and bottom, and a sealing strip (47) is provided inside the expansion joint (46) of the container (4).

6. The dimethyl ether distillation column apparatus according to claim 5, characterized in that: Two sealing strips (47) are provided and are arranged side by side along the width direction of the expansion joint (46), and a long strip gasket (471) is inserted between the two sealing strips (47).

7. The dimethyl ether distillation column apparatus according to claim 6, characterized in that: The sealing strip (47) is made of rubber. The two sealing strips (47) are provided with polytetrafluoroethylene lubricating layers (472) on opposite sides. The two sides of the long strip gasket (471) respectively abut against the two polytetrafluoroethylene lubricating layers (472).

8. The dimethyl ether distillation column apparatus according to claim 2, characterized in that: The inner circumferential surface of the container (4) is set as a conical surface, and the inner diameter of the container (4) gradually increases from top to bottom.

9. The dimethyl ether distillation column apparatus according to claim 8, characterized in that: The lower end of the container (4) is detachably connected to a filler (2) support plate (7), and the upper end of the container (4) is provided with a hoisting structure (10).

10. A dimethyl ether distillation column apparatus according to claim 9, characterized in that: An elastic buffer (8) is provided between the lower end of the filler (2) support plate (7) and the container (4); the elastic buffer (8) is a sheet metal part and has an overall annular groove structure. The annular groove opening of the elastic buffer (8) faces downward, and the inner and outer sidewalls of the elastic buffer (8) gradually move away from each other from top to bottom.

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