Gas distributor and reactor

Abstract

The present application relates to the field of gas phase synthesis, and discloses a gas distributor and a reactor, wherein the gas distributor (2) comprises a distribution plate (21) with openings around a central axis, the distribution plate (21) surrounds a spiral channel extending outward from the center, the distribution plate (21) is provided in the structure of a circular truncated cone with the outer diameter gradually increasing along the central axis from the feed end to the discharge end, the top of the distribution plate (21) is provided with an upper end plate (24), the center of the upper end plate (24) is provided with a feed port, and the bottom of the distribution plate (21) is connected with an end plate (22) with through holes. The gas distributor can make the material flow spirally therein to be fully mixed, and gradually diffuse outward during the flow process, and flow and diffuse outward from the discharge end and the outer periphery to distribute the material in more directions, so that the material is uniformly distributed.

Description

Technical Field

[0001] This invention relates to the field of gas-phase synthesis, specifically to a gas distributor, and also to a reactor. Background Technology

[0002] Vinyl acetate (VAc), also known as vinyl acetate ester, is a colorless, flammable liquid with a strong odor. It is one of the most widely used organic chemical raw materials globally, primarily used in the production of polyvinyl alcohol (PVA), vinyl acetate resin (PVAc), vinyl acetate-ethylene copolymer emulsion (VAE) or copolymer resin (EVA), vinyl acetate-vinyl chloride copolymer (EVC), polyacrylonitrile comonomers, and derivatives such as acetal resins. Vinyl acetate has broad application prospects in coatings, aerospace, construction, textiles, and soil improvement. The main production processes for vinyl acetate include the calcium carbide acetylene method, the petroleum ethylene method, and the natural gas acetylene method, with significant cost differences. Among these, 80% of vinyl acetate is produced through the ethylene gas-phase method.

[0003] The gas-phase process for producing vinyl acetate uses a gaseous mixture of ethylene, acetic acid, and oxygen as raw materials. Under the action of a catalyst, the mixture reacts to produce vinyl acetate, with small amounts of byproducts such as acetaldehyde, ethyl acetate, methyl acetate, acrolein, diacetate, and polymers. The reaction equation is as follows: Main reaction:

[0004] Main side reactions:

[0005] In this process, various gaseous reactants need to be thoroughly mixed and evenly distributed within the reaction section of the reactor to ensure the synthesis reaction proceeds fully. In existing technologies, the gases are not sufficiently and evenly mixed, and it is difficult to guarantee that the gas mixture is evenly distributed within the reaction section, resulting in low synthesis efficiency. Summary of the Invention

[0006] The purpose of this invention is to provide a gas distributor and a reactor to solve the problems of insufficient mixing and uneven distribution of reactant gases.

[0007] To achieve the above objectives, the present invention provides a gas distributor, wherein the gas distributor includes a distribution plate with openings surrounding a central axis, the distribution plate forming a spiral channel extending outward from the center, the distribution plate being configured as a frustum structure with an outer diameter gradually increasing from the feed end to the discharge end along the central axis, the top of the distribution plate being provided with an upper end plate, the center of the upper end plate being provided with a feed inlet, and the bottom end of the distribution plate being connected to an end plate with through holes.

[0008] Optionally, the opening may include a strip-shaped opening extending from the feed end toward the discharge end and extending circumferentially.

[0009] Optionally, one end of the outermost ring of the distribution plate is attached to the outer circumferential surface of the adjacent inner ring. Optionally, the apex angle of the frustum structure is 60°~140°.

[0010] Optionally, the opening ratio of the distribution plate is 15% to 80%, and the opening ratio of the lower end plate is 20% to 80%.

[0011] Optionally, the upper end of the conical tube formed by the innermost ring of the distribution plate is aligned with the feed inlet.

[0012] On the other hand, the present invention also provides a reactor, wherein the reactor includes a shell, a feed pipe disposed on the top of the shell, and a gas distributor as described above, wherein the feed port of the gas distributor is connected to the feed pipe.

[0013] Optionally, the ratio of the height of the gas distributor to the inner diameter of the housing is 0.4-0.7.

[0014] Optionally, the reactor is provided with a reaction section located below the gas distributor. The reaction section includes a first spiral plate and a second spiral plate extending spirally from the inside to the outside around the central axis of the shell. A spiral reactant channel and a heat dissipation fluid channel are formed between the first spiral plate and the second spiral plate.

[0015] Optionally, the reaction section includes sealing plates respectively disposed at the upper and lower ends to close the heat-relieving fluid channel, and the reactor includes a heat-relieving fluid inlet pipe disposed on the side of the shell and connected to the heat-relieving fluid channel and a heat-relieving fluid outlet pipe partially disposed at the center of the reaction section and connected to the heat-relieving fluid channel, the heat-relieving fluid outlet pipe extending from the upper side of the reaction section to the outside of the shell.

[0016] Optionally, the reaction section includes a plurality of liquid distributors arranged at intervals along the height direction and connected to the heat-relieving fluid channel. Each liquid distributor is provided with an inlet connected to the heat-relieving fluid inlet pipe and a plurality of guide holes arranged at intervals along the height direction and connected to the heat-relieving fluid channel.

[0017] Optionally, the ratio of the opening area of ​​the flow guide hole to the cross-sectional area of ​​the heat dissipation fluid inlet pipe is 0.4 to 0.9.

[0018] Optionally, the ratio of the width of the heat-relieving fluid channel to the width of the reactant channel is 0.3-0.6.

[0019] Alternatively, the upper end of the reactant channel opens upward and the lower end opens downward.

[0020] Alternatively, the reactor may include a support grid that supports the reaction section.

[0021] Through the above technical solution, the gas distributor allows the material to flow spirally within it for thorough mixing, and gradually diffuses outward during the flow process, spreading outward from the bottom and outer periphery to distribute the material in more directions, thereby achieving uniform material distribution. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the gas distributor according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the lower end plate according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the reactor structure according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the reaction section according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the liquid distributor according to an embodiment of the present invention.

[0023] Explanation of reference numerals in the attached figures 1-Feed pipe, 2-Gas distributor, 3-Shell, 4-Reaction section, 5-Heat dissipation fluid inlet pipe, 6-Discharge pipe, 7-Heat dissipation fluid outlet pipe, 8-Support grid, 21-Distribution plate, 22-Lower end plate, 23-Strip hole, 24-Upper end plate, 31-Upper end head, 32-Cylinder, 33-Lower end head, 41-First spiral plate, 42-Second spiral plate, 43-Reactant channel, 44-Heat dissipation fluid channel, 45-Distributor, 46-Guide hole. Detailed Implementation

[0024] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0025] refer to Figures 1-5 As shown, the present invention provides a gas distributor, wherein the gas distributor 2 includes a distribution plate 21 with openings around a central axis, the distribution plate 21 forming a spiral channel extending outward from the center, the distribution plate 21 being configured as a frustum structure with an outer diameter gradually increasing from the feed end to the discharge end along the central axis, the top of the distribution plate 21 being provided with an upper end plate 24, the center of the upper end plate 24 being provided with a feed inlet, and the bottom of the distribution plate 21 being connected to a lower end plate 22 with through holes.

[0026] The gas distributor 2 includes a distribution plate 21, which extends spirally from the center outwards to form a spiral channel between multiple layers of distribution plates 21. (Refer to...) Figure 1 As shown; on the other hand, the distribution plate 21 is formed as a frustum structure, that is, a shape in which the outer perimeter gradually increases from one end to the other. The end with the smaller outer perimeter is connected to the upper end plate 24, and the other end is connected to the lower end plate 22. The upper end plate 24 has a feed port at its center, which can introduce gas into the center of the spiral channel and allow the gas to diffuse outward along the spiral channel, thereby diffusing outward through the openings on the outer distribution plate 21 to achieve gas distribution.

[0027] Additionally, the lower end plate 22 is connected to the bottom of the distribution plate 21, and a through hole is formed thereon, as shown in the reference. Figure 2 As shown, the lower end plate 22 restricts the material from being discharged directly from the spiral channel to a certain extent.

[0028] During the material distribution and conveying process, the material enters the center of the spiral channel from the feed inlet. On the one hand, it flows outward along the spiral channel, and on the other hand, it flows to the lower end plate 12. During the flow, due to the increase in flow area, the material gradually diffuses. In particular, it can flow from the inner spiral channel through the openings on the distribution plate 21 to the adjacent outer spiral channel. In addition, the through holes on the bottom end plate 22 allow the material to pass through partially. On the other hand, the material flows outward in the outermost spiral channel through the openings on the outermost distribution plate 21. That is, the material flows out from the bottom and the outer periphery respectively, so as to distribute the material in as many directions as possible.

[0029] In this scheme, the gas distributor allows the material to flow spirally within it for thorough mixing, and gradually diffuses outward during the flow, spreading from the bottom and outer periphery to distribute the material in more directions, thus achieving uniform material distribution.

[0030] The opening includes both circumferentially extending strip-shaped holes 23 extending from the feed end toward the discharge end. Some strip-shaped holes 23 extend generally along the generatrix direction of the conical structure, while others extend circumferentially. In other embodiments, the opening may also be of other shapes, such as circular holes, triangular holes, quadrilateral holes, etc.

[0031] One end of the outermost ring of the distribution plate 21 is attached to the outer peripheral surface of the adjacent inner ring. (Reference) Figure 1 As shown, the outermost end of the distribution plate 21 is attached to the outer circumferential surface of the inner ring to seal the outlet of the spiral channel, preventing the gas from being discharged directly from the outlet, and instead forcing it to diffuse outward through the opening, thereby improving the uniformity of distribution.

[0032] The apex angle of the frustum structure is 60°~140°. This apex angle refers to the angle between the two sides in the trapezoidal cross-section passing through the central axis of the frustum structure. This apex angle reflects the increasing dimensional trend of the gas distributor 2 from the feed end to the discharge end.

[0033] The distribution plate 21 has an opening ratio of 15% to 80%, and the end plate 22 has an opening ratio of 20% to 80%.

[0034] The upper end of the conical tube formed by the innermost ring of the distribution plate 21 is aligned with the feed inlet. (Reference) Figure 1 As shown, the distribution plate 21 forms a relatively complete tubular structure at the innermost circle. This tubular structure gradually expands from the feed inlet to the other end, forming a conical structure (or frustum shape). The upper end of the conical tube is aligned with the feed inlet. The gas entering the conical tube from the feed inlet diffuses outward through the openings on the distribution plate 21 to enter the spiral channel and flow outward in the spiral channel, improving the uniformity of distribution.

[0035] The gas distributor 2 is mainly used to transport gas, but other forms of materials may also be mixed in it.

[0036] The upper end of the conical tube formed by the innermost ring of the distribution plate 21 is aligned with the feed inlet. The innermost ring of the distribution plate 21 forms a complete conical tube, and the opening at its upper end is aligned with the feed inlet on the upper end plate 24. Gas enters the conical tube and can diffuse through the strip-shaped hole 23 into the outer spiral channel.

[0037] On the other hand, the present invention also provides a reactor, with reference to Figure 4 As shown, the reactor includes a shell 3, a feed pipe 1 disposed on the top of the shell 3, and a gas distributor 2 according to the above scheme, wherein the feed port of the gas distributor 2 is connected to the feed pipe 1.

[0038] The shell 3 is generally cylindrical, with a feed pipe 1 communicating with its interior at the top. The lower end of the feed pipe 1 is connected to a gas distributor 2, allowing the material entering through the feed pipe 1 to be distributed into the shell 3 via the gas distributor 2. The shell 3 includes an upper end cap 31, a cylindrical body 32, and a lower end cap 33. The feed pipe 1 is located on the upper end cap 31, and the lower end cap 33 is connected to a discharge pipe 6. The reaction section 4 is located inside the cylindrical body 32.

[0039] The ratio of the height of the gas distributor 2 to the inner diameter of the housing 3 is 0.4-0.7. The inner diameter of the housing 3 refers to its maximum inner diameter, such as the inner diameter of the cylinder 32. The height of the gas distributor 2 reflects, to some extent, the length of the path through which the material flows. The greater the height, the longer the material flow path, allowing for greater diffusion to the periphery and improving the uniformity of distribution. Of course, the height of the gas distributor 2 is also limited by the dimensions of the housing 3; therefore, the height of the gas distributor 2 needs to be selected based on the inner diameter of the housing 3.

[0040] The reactor includes a reaction section 4 located below the gas distributor 2. The reaction section 4 comprises a first spiral plate 41 and a second spiral plate 42 extending spirally from the inside out around the central axis of the shell 3. A spiral reactant channel 43 and a heat-removing fluid channel 44 are formed between the first spiral plate 41 and the second spiral plate 42. The reaction section 4 is the main reaction component, forming two adjacent spiral channels through the two spiral plates, namely the first spiral plate 41 and the second spiral plate 42: the reactant channel 43 for containing reactants and the heat-removing fluid channel 44 for containing heat-removing fluid. The reactant channel 43 and the heat-removing fluid channel 44 extend spirally from the inside out to maximize the contact area between the two channels, allowing the heat generated in the reactant channel 43 to be more fully transferred to the heat-removing fluid channel 44. The first spiral plate 41 and the second spiral plate 42 can be corrugated plates to increase the heat exchange area of ​​the reactant channel 43 and the heat-removing fluid channel 44.

[0041] Additionally, the reaction section 4 includes sealing plates respectively disposed at the upper and lower ends to close the heat-relief fluid channel 44. The reactor includes a heat-relief fluid inlet pipe 5 disposed on the side of the shell 3 and connected to the heat-relief fluid channel 44, and a heat-relief fluid outlet pipe 7 partially disposed at the center of the reaction section 4 and connected to the heat-relief fluid channel 44. The heat-relief fluid outlet pipe 7 extends from the upper side of the reaction section 4 to the outside of the shell 3. Heat-relief fluid can be injected into the heat-relief fluid channel 44 through the heat-relief fluid inlet pipe 5. The heat-relief fluid flows along a spiral path from the outer periphery to the center through the heat-relief fluid inlet pipe 5, finally entering the heat-relief fluid outlet pipe 7 and being discharged to the outside of the shell 3. The heat-relief fluid outlet pipe 7 includes a vertical portion located at the central axis and a horizontal portion extending horizontally from the upper end of the vertical portion to the outside of the shell 3.

[0042] Additionally, the reaction section 4 includes a plurality of liquid distributors 45 arranged at intervals along the height direction and connected to the heat-relieving fluid channel 44. Each liquid distributor 45 is provided with an inlet connected to the heat-relieving fluid inlet pipe 5 and a plurality of guide holes 46 arranged at intervals along the height direction and connected to the heat-relieving fluid channel 44. (Reference) Figure 4 and Figure 5 As shown, the liquid distributor 45 is generally formed as a cubic box, with an inlet at one end for connection to the heat-relief fluid inlet pipe 5, and multiple guide holes 46 at the other end. The liquid distributor 45 can distribute the liquid from the heat-relief fluid inlet pipe 5 into multiple branches arranged along the height direction, so that the multiple branches are guided into the heat-relief fluid channel 44 through the guide holes 46, thereby improving the uniformity of heat-relief fluid distribution. The liquid distributor 45 can be disposed inside the housing 3, but in other embodiments, it can also be disposed outside.

[0043] The ratio of the opening area of ​​the guide hole 46 to the cross-sectional area of ​​the heat-relieving fluid inlet pipe 5 is 0.4 to 0.9. The ratio of the width of the heat-relieving fluid channel 44 to the width of the reactant channel 43 is 0.3 to 0.6. (Reference) Figure 4 As shown, the reactant channel 43 has a relatively large width, while the heat dissipation fluid channel 44 has a relatively small width. This means that in the reaction section 4, the reactant channel 43 occupies the majority of the space to achieve the corresponding reaction. The width of the channel refers to its approximate dimension along the radial direction (with a certain angle to the radial direction). Furthermore, the width of the heat dissipation fluid channel 44 is no greater than 40 mm.

[0044] The reactant channel 43 opens upwards at its upper end and downwards at its lower end. The opening at both ends of the reactant channel 43 allows material from the upper part to enter and reaction products to exit from the lower end. A catalyst can be placed in the reactant channel 43 to catalyze the reactants. That is, in the reactant channel 43, the reactants and products generated during the reaction mainly flow in a downward direction; however, this does not exclude flow along the spiral path of the spiral channel.

[0045] Furthermore, the reactor includes a support grid 8 that supports the reaction section 4. The support grid 8 can support the first spiral plate 41, the second spiral plate 42, and in particular, materials such as catalysts in the reactant channel 43.

[0046] The reactor can be used to synthesize vinyl acetate, and of course, it can also be used for other similar reactions.

[0047] The following are examples of the synthesis of vinyl acetate using the reactor in this scheme.

[0048]

Example 1

[0049]

Example 2

[0050]

Example 3

[0051]

Example 4

[0052]

Example 5

[0053]

Example 6

[0054] [Comparative Example] The reactor structure parameters and process conditions are the same as in Example 2. The difference is that the device uses a ring gas distributor similar to that in patent CN202893319U, and the yield of vinyl acetate is 88%.

[0055] The comparison shows that, due to the use of a spiral frustum-shaped gas distributor, the gas can be distributed more evenly in the reactor, which can improve the product yield.

[0056] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A gas distributor, characterized in that, The gas distributor (2) includes a distribution plate (21) with openings around a central axis. The distribution plate (21) forms a spiral channel extending outward from the center. The distribution plate (21) is configured as a frustum structure with an outer diameter that gradually increases from the feed end to the discharge end along the central axis. The top of the distribution plate (21) is provided with an upper end plate (24). The center of the upper end plate (24) is provided with a feed port. The bottom of the distribution plate (21) is connected to a lower end plate (22) with through holes. The gas distributor allows material to flow from the inner spiral channel through the openings on the distribution plate (21) to the adjacent outer spiral channel, and the material can flow and diffuse outward from the bottom and periphery of the gas distributor.

2. The gas distributor according to claim 1, characterized in that, The opening includes a strip-shaped opening (23) extending from the feed end toward the discharge end and extending circumferentially.

3. The gas distributor according to claim 1, characterized in that, One end of the outermost ring of the distribution plate (21) is attached to the outer circumferential surface of the adjacent inner ring.

4. The gas distributor according to claim 1, characterized in that, The apex angle of the frustum structure is 60°~140°.

5. The gas distributor according to claim 1, characterized in that, The opening ratio of the distribution plate (21) is 15%~80%, and the opening ratio of the lower end plate (22) is 20%~80%.

6. The gas distributor according to claim 1, characterized in that, The upper end of the tapered tube formed by the innermost ring of the distribution plate (21) is aligned with the feed inlet.

7. A reactor, characterized in that, The reactor includes a shell (3), a feed pipe (1) disposed on the top of the shell (3), and a gas distributor (2) according to any one of claims 1-6, wherein the inlet of the gas distributor (2) is connected to the feed pipe (1).

8. The reactor according to claim 7, characterized in that, The ratio of the height of the gas distributor (2) to the inner diameter of the housing (3) is 0.4-0.

7.

9. The reactor according to claim 7, characterized in that, The reactor is provided with a reaction section (4) located below the gas distributor (2). The reaction section (4) includes a first spiral plate (41) and a second spiral plate (42) extending spirally from the inside to the outside around the central axis of the shell (3). A spiral reactant channel (43) and a heat removal fluid channel (44) are formed between the first spiral plate (41) and the second spiral plate (42).

10. The reactor according to claim 9, characterized in that, The reaction section (4) includes sealing plates respectively disposed at the upper and lower ends to close the heat-relief fluid channel (44). The reactor includes a heat-relief fluid inlet pipe (5) disposed on the side of the shell (3) and connected to the heat-relief fluid channel (44) and a heat-relief fluid outlet pipe (7) partially disposed at the center of the reaction section (4) and connected to the heat-relief fluid channel (44). The heat-relief fluid outlet pipe (7) extends from the upper side of the reaction section (4) to the outside of the shell (3).

11. The reactor according to claim 10, characterized in that, The reaction section (4) includes a plurality of liquid distributors (45) arranged at intervals along the height direction and connected to the heat-removing fluid channel (44). Each liquid distributor (45) is provided with an inlet connected to the heat-removing fluid inlet pipe (5) and a plurality of guide holes (46) arranged at intervals along the height direction and connected to the heat-removing fluid channel (44).

12. The reactor according to claim 11, characterized in that, The ratio of the opening area of ​​the guide hole (46) to the cross-sectional area of ​​the heat dissipation fluid inlet pipe (5) is 0.4 to 0.

9.

13. The reactor according to claim 9, characterized in that, The ratio of the width of the heat-removing fluid channel (44) to the width of the reactant channel (43) is 0.3-0.

6.

14. The reactor according to claim 9, characterized in that, The upper end of the reactant channel (43) opens upward and the lower end opens downward.

15. The reactor according to claim 9, characterized in that, The reactor includes a support grid (8) that supports the reaction section (4).

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