Liquid distributor and small rectification column

Abstract

The utility model discloses a liquid distributor and small rectifying tower. The liquid distributor is composed of flat bottom conical distribution disc, and the disc surface is provided with array type first spray pipe, and the side wall is provided with second spray pipe; a plurality of steam rising pipes are arranged on the distribution disc and overflow port is arranged, and steam rising cap can be matched. The liquid inlet of first and second spray pipes and the overflow port of steam rising pipe adopt the same height reference, which can stabilize the working liquid level and realize uniform static pressure head. In the whole tower scheme, the liquid phase feed is arranged in the lower bend, the gas phase adopts cross intersection branch pipe to realize pre-distribution, and the distributor and the filler maintain reasonable spacing. The structure can significantly improve the near-wall wetting, inhibit wall flow and channel flow, reduce back mixing and entrainment, improve the mass transfer efficiency and separation stability of the first stage, and has the engineering advantages of clear assembly reference and convenient maintenance.

Description

Technical Field

[0001] This utility model relates to the field of chemical separation equipment technology, specifically to a liquid distributor for a small distillation column and a small distillation column containing the liquid distributor, belonging to the technology of column internal structure optimization and gas-liquid distribution control. Background Technology

[0002] Distillation columns, as important unit operation equipment in chemical engineering, are widely used in chemical plants for the separation and purification of materials. However, during operation, distillation columns are prone to wall flow, especially for small-diameter columns. The liquid phase inside the column tends to flow along the column wall into the bottom, failing to achieve sufficient contact with the gas phase within the packing, thus reducing the separation efficiency and preventing the distillation column from meeting design requirements. Therefore, in column design, a liquid phase distributor is typically installed above each layer of packing to ensure the uniform distribution of the liquid phase within the packing, increasing the contact area between the gas and liquid phases, and enabling the distillation column to achieve optimal separation performance.

[0003] Currently, the most commonly used liquid phase distributor in distillation columns is the tray-type distributor, which provides good distribution in distillation columns with a diameter greater than 1200 mm. However, it is not suitable for distillation columns with a diameter less than 1000 mm due to its complex structure, high manufacturing and installation difficulty. In the design of small distillation columns, to ensure distillation efficiency, the column diameter and top reflux flow rate are often increased, along with the packing height, and simple liquid phase distributors such as conical rings are used to achieve uniform liquid phase distribution. This not only increases the manufacturing cost of the column but also increases the overall pressure drop, leading to an increase in the reboiler temperature, which has certain adverse effects on the design and operation of the distillation column. Therefore, an efficient small distillation column and a suitable gas-liquid phase distributor are particularly important for the design of small distillation columns.

[0004] Chinese patent CN219272187U discloses a liquid redistributor structure for a small packed distillation column, mainly including a wall flow collection plate, a liquid collection cylinder, vapor phase distribution holes, and liquid phase distribution holes. By setting the volume of liquid flowing out through the liquid phase distribution holes to be smaller than the volume of liquid flowing to the bottom of the liquid collection cylinder, the condensed liquid can accumulate at the bottom of the liquid collection cylinder to form a certain liquid level space. This accumulated liquid can completely block multiple liquid phase distribution holes, allowing the vapor phase flowing upward from the bottom of the column to only flow through the vapor phase distribution holes to the space above the liquid collection cylinder. This avoids the formation of vapor phase obstruction vortices, thereby avoiding mass transfer back mixing and the problem of increased packing plate height. This patent, when applied to a small distillation column, can prevent wall flow and improve the liquid phase distribution effect to a certain extent. However, because the vapor phase must pass through the water film generated by the liquid phase flow when passing through the vapor phase distribution holes, foaming is easily formed when the vapor phase flow rate is high, which is not conducive to the distillation of the column. At the same time, the liquid phase distribution holes have no guide pipes, resulting in a slightly poor liquid phase distribution effect.

[0005] Chinese patent CN214861268U discloses a liquid distribution device for a small distillation column. The device consists of an upper distributor and a lower distributor. The upper distributor, located below the feed pipe, comprises a hammer-shaped cap and a cone. The cap is connected and fixed to the cone via a connecting block. The cone is fixed in the center of the column by a bottom support block, which is welded to the inner wall of the column by two left and right support strips. The lower distributor is located above the packing fixing member at the bottom of the column. This patent, applied to a small distillation column, utilizes the cap and cone to improve liquid distribution to some extent. However, its flow channels are limited, resulting in uneven distribution. Furthermore, the liquid phase channel overlaps with part of the vapor phase channel, easily causing gas blockage and foaming, thus affecting the distillation effect. Utility Model Content

[0006] This invention aims to solve problems such as easy wall flow, unstable liquid level, and uneven gas-liquid distribution before entering the packing layer in small-diameter distillation units. It proposes a compact liquid distributor and a small distillation column with clearly defined assembly standards. The liquid distributor uses a flat-bottomed conical disc as its body. An array of first spray pipes is installed on the base, and second spray pipes are fixed to the side wall of the distributor to form circumferential spraying. Multiple steam riser pipes are installed on the distributor, with overflow outlets formed on them. By setting the liquid inlets of the first and second spray pipes and the overflow outlets of the steam riser pipes to the same height, the working liquid level within the liquid distributor is made consistent and stable. This ensures that each spray outlet receives a basically consistent static pressure head to uniformly wet the upper surface of the packing layer, guaranteeing uniform contact between the liquid phase and the gas phase in the packing layer, resulting in optimal distillation performance.

[0007] According to a first aspect of this utility model, a liquid distributor for a small distillation column is provided, comprising:

[0008] The distribution plate installed inside the tower is composed of a flat-bottomed conical disc, with a horizontal base and an upwardly inclined annular sidewall;

[0009] The first spray pipe is installed on the base of the distribution plate;

[0010] A second spray pipe is fixed to the side wall of the distribution plate, and the second spray pipe is arranged around the circumference of the distribution plate;

[0011] Steam riser pipes are installed on the distribution plate, and the steam riser pipes are provided with overflow ports;

[0012] The liquid inlet of the first spray pipe, the liquid inlet of the second spray pipe, and the overflow outlet of the steam riser are at the same height to form a consistent liquid level when the distribution plate is working.

[0013] In some technical solutions, the outer diameter of the distribution plate base is 0.5 to 0.9 times the diameter of the distillation column, and the inclination angle of the side wall of the distribution plate relative to the base is 45° to 85°.

[0014] In some technical solutions, the first spray pipe consists of multiple pipes, which are evenly arranged in a triangular or square array on the base of the distribution plate.

[0015] In some technical solutions, the inlet and / or outlet of the first spray pipe has a serrated structure.

[0016] In some technical solutions, the outer diameter of the second spray pipe is 0.3 to 0.7 times the outer diameter of the first spray pipe, and the second spray pipe is arranged continuously or in segments along the circumferential sidewall of the distribution plate.

[0017] In some technical solutions, the steam riser pipes are multiple, evenly arranged on the base of the distribution plate in a triangular or square array; the total flow cross-sectional area of ​​the steam riser pipes accounts for 15% to 50% of the cross-sectional area of ​​the distillation column.

[0018] In some technical solutions, the upper end of the steam riser is provided with an inverted triangular or conical steam riser cap, and an annular gap is formed between the steam riser cap and the steam riser to evenly distribute the rising gas.

[0019] In some technical solutions, the overflow port of the steam riser pipe is an annular overflow edge, a notch, or a slotted structure; and / or,

[0020] The height of the steam riser pipe is 100–400 mm; and / or,

[0021] The diameter of the first spray pipe is 4 to 20 mm.

[0022] According to a second aspect of this utility model, a small distillation column is further provided, comprising: a column body, at least one packing layer, a reflux or feed liquid supply system, and a liquid distributor installed above the packing layer; wherein the liquid distributor is the liquid distributor described above.

[0023] The tower body is provided with a liquid feed pipe on its side wall. After entering the tower body, the liquid feed pipe bends downwards towards the center of the tower body. The distance between the downward bend of the pipe and the top of the liquid distributor is 50-200 mm. The distance between the lower surface of the liquid distributor and the upper surface of the packing layer is 100-300 mm.

[0024] The lower part of the tower body is equipped with a gas feed pipe, which is arranged in a cross shape, and gas branch pipes are arranged at certain intervals on it.

[0025] In some technical solutions, the liquid distributor and the packing layer are arranged alternately in the height direction of the tower body, with 1 to 6 groups.

[0026] The present invention, by adopting the above technical solution, has at least the following beneficial effects:

[0027] 1. In this invention, a flat-bottomed conical disc is used as the distribution disc body, and a second spray pipe is fixed to the side wall. Simultaneously, the liquid inlets of the first and second spray pipes are set at the same height as the overflow outlet of the steam riser, creating a uniform and stable working liquid level within the distribution disc. This ensures that each spray outlet receives a basically consistent static head, and the droplet size and spray surface density remain stable in the circumferential direction. This significantly reduces liquid deviation and near-wall dry zones under small tower diameter conditions, and the upper surface of the packing is more uniformly wetted, thereby suppressing wall flow and reducing mass transfer efficiency fluctuations caused by liquid level fluctuations.

[0028] 2. In this utility model, the second spray pipe is installed on the side wall of the distribution plate and is arranged continuously or in segments around the circumference, which takes into account both compact structure and convenient maintenance. The side wall pipe is close to the near-wall packing area, which can compensate for wetting of the edge zone that is difficult to cover by traditional distributors. With the addition of the stable static pressure head brought by the equal liquid level, the liquid film in the near-wall area is more continuous, and the liquid exchange between the wall and the packing interface is enhanced.

[0029] 3. In this utility model, the inlet and outlet of the first spray pipe adopt a sawtooth port structure, which can guide and evenly distribute the liquid phase, and at the same time quickly break the surface tension of the liquid, which is beneficial to the dispersion of the liquid phase.

[0030] 4. In this invention, multiple steam riser pipes are arranged evenly in a triangular or square array, with the total flow cross-sectional area accounting for 15% to 50% of the tower cross-section. Structurally, this provides ample and balanced channels for the rising gas. This opening ratio window avoids the damage to the liquid film caused by localized high-speed jets when the gas passes through the distribution plate, and also avoids weir pressure rise and back mixing caused by excessively low opening ratios. It maintains a gentle velocity distribution and moderate turbulence of the gas phase before entering the packing layer, which is conducive to the formation of a stable gas-liquid contact interface through uniform superposition with the liquid phase.

[0031] 5. In this invention, the effective height of the steam riser is controlled between 100 and 400 mm, and an inverted triangular or conical steam riser cap is provided at the upper end, forming an annular gap between the cap and the pipe opening. This structure can weaken the axial momentum of the rising airflow, suppress liquid backflow, and allow the gas to undergo radial diffusion once in the annular gap, thereby forming a more uniform velocity profile above the distribution plate.

[0032] 6. In this utility model, the outer diameter of the distribution plate is selected to be 0.5 to 0.9 times the tower diameter, and the side wall inclination angle is 45° to 85°. On the one hand, the outer diameter ensures that the plate surface is sufficient for spraying and steam raising; on the other hand, the inclined side wall enhances the liquid-bearing and liquid-guiding function of the plate edge, and the liquid forms a controlled backflow along the side wall. With the compensation of side wall spraying, the liquid coverage at the plate edge is more sufficient, reducing the liquid loss from the outer edge of the plate to the packing layer.

[0033] 7. In this invention, the liquid feed inlet bends downward after entering the tower and maintains a distance of 50-200mm from the top of the distributor, which can effectively reduce the disturbance of the free fall of the feed to the liquid level on the plate and the uniformity of the spray; the distance between the lower surface of the distributor and the upper surface of the packing is maintained at 100-300mm, providing the necessary redistribution and momentum decay space, so that the droplets complete the rectification of velocity and direction before entering the packing layer, reducing the probability of penetration and channeling. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings and their markings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the liquid distributor according to an embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram of the structure of the small distillation column described in an embodiment of the present invention;

[0037] Figure 3 This is a diagram showing the arrangement of the steam riser pipe and spray pipe according to an embodiment of the present invention.

[0038] The meanings of the symbols marked in the figure are as follows:

[0039] 10—Tower body, 11—Gas outlet, 12—Liquid feed pipe, 13—Gas feed pipe, 14—Tower bottom liquid outlet, 20—Liquid distributor, 30—Packing layer;

[0040] 201—Distribution plate, 202—Side wall of distribution plate, 203—Second spray pipe, 204—Chassis, 205—First spray pipe, 206—Steam riser pipe, 207—Steam riser cap, 208—Overflow port;

[0041] 131—Gas branch pipe;

[0042] θ—Angle between the side wall of the distribution plate and the base plate; H1—Distance between the bottom of the liquid distributor and the packing layer; H2—Height of the steam riser; H3—Distance between the liquid feed pipe inlet and the top of the liquid distributor; L—Ratio of base plate diameter to tower diameter. Detailed Implementation

[0043] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the specific implementation methods of this utility model will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of this utility model. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0044] To keep the drawings concise, each figure only schematically shows the parts relevant to the utility model, and these do not represent the actual structure of the product. Furthermore, for ease of understanding, in some figures, only one of the components with the same structure or function is schematically depicted, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0045] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0046] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0047] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0048] According to one embodiment of this application, a liquid distributor for a small distillation column is provided, installed inside the column body 10 and located above the packing layer 30, such as... Figure 1 The liquid distributor 20 includes a distribution plate 201, a first spray pipe 205, a second spray pipe 203, and a steam riser 206.

[0049] In the specific design, the distribution plate 201 adopts a flat-bottomed conical disc structure, consisting of a horizontal base 204 and an upwardly inclined annular sidewall. The distribution plate 201 serves as a load-bearing and reference component, providing a planar layout for the first spray pipe array 205, and forming a stable assembly reference with the tower body 10 through its sidewall. In a preferred embodiment, the outer diameter of the distribution plate base is 0.5 to 0.9 times the diameter of the distillation tower, ensuring sufficient plate surface for spraying and steam generation. Furthermore, the inclination angle of the sidewall of the distribution plate 201 relative to the base 204 is 45° to 85°. The inclined sidewall enhances the liquid-bearing and guiding function of the plate edge, allowing the liquid to form a controlled reflux along the sidewall.

[0050] The first spray pipe 205 is mounted on the base of the distribution tray. Specifically, multiple first spray pipes 205 are arranged in an array evenly on the tray surface, as shown in the reference. Figure 3 The array arrangement adopts a regular geometric pattern (such as triangles or squares), which facilitates the achievement of approximately equidistant and equal flow rate distribution on a limited disk surface. Specifically, the diameter of the first spray pipe is 4-20 mm, and multiple spray nozzles are opened on the pipe wall, with the nozzles arranged at regular intervals along the circumference and / or radial direction. In this embodiment, the evenly distributed multi-pipe configuration can form a high coverage initial distribution on the disk surface, thereby reducing the burden of subsequent redistribution. This arrangement enables the upper surface of the packing layer 30 to obtain more uniform liquid wetting, reduces the tendency of local channeling, and makes mass transfer more stable.

[0051] The second spray pipe 203 is fixed to the side wall of the distribution plate 201. Specifically, the second spray pipe 203 is arranged continuously or in segments along the circumference of the side wall. In a preferred embodiment, the outer diameter of the second spray pipe 203 is 0.3 to 0.7 times the outer diameter of the first spray pipe, to achieve a balance between compensatory wetting in the near-wall region and overall uniform distribution. This side-wall spraying method significantly improves the wetting state of the packing area adjacent to the tower wall, suppresses wall flow and edge short-circuiting, and reduces theoretical stage losses.

[0052] In a preferred embodiment, the inlet and outlet ends of the first spray pipe 205 adopt a serrated port structure. This structural design can guide and evenly distribute the liquid phase, while quickly breaking the surface tension of the liquid surface, which is beneficial to the dispersion of the liquid phase.

[0053] Steam riser pipes 206 are evenly distributed on the base of the distribution plate, and overflow ports 208 are formed on them. For specific implementation details, refer to... Figure 3The steam riser pipes 206 are evenly distributed in a regular array, with the array arrangement adopting a regular geometric pattern (such as triangles or squares), which facilitates the distribution effect of approximately equidistant and equal flow rates on a limited disk surface. The upper end can be equipped with an inverted triangular or conical steam riser cap 207, forming an annular gap between the cap and the pipe opening, allowing the rising gas to undergo radial diffusion and momentum rectification before entering the upper space. The overflow port 208 can adopt different structural forms such as annular overflow edge, notch, or slot to match the operating requirements of different loads and systems. In a preferred embodiment, the total flow cross-sectional area of ​​the steam riser pipes 206 accounts for 15% to 50% of the cross-sectional area of ​​the distillation column, resulting in a smoother velocity profile, reduced backmixing and entrainment, and less disturbance to the liquid film when the gas phase passes through the distribution disk 201, which is beneficial for the uniform superposition of the gas and liquid phases to form a stable gas-liquid interface.

[0054] In this embodiment, the equal-height design is applied to both the liquid supply and steam riser subsystems: the liquid inlet of the first spray pipe, the liquid inlet of the second spray pipe, and the overflow port of the steam riser pipe are set as equal-height references. In terms of implementation results, the working liquid level of the distribution plate 201 tends to be uniform and stable during operation, each spray nozzle obtains a basically consistent static pressure head, the droplet size and spray surface density are more uniform in the circumferential direction, and the fluctuations in mass transfer and separation indicators are reduced.

[0055] In this embodiment, the geometric design of "flat-bottomed conical disc + side wall spray pipe" and the equal height design of spray / overflow are used to achieve the consistency and stability of the working liquid level in the liquid distributor 20, so that each spray nozzle can obtain a basically consistent static pressure head to uniformly wet the upper surface of the packing. While suppressing wall flow, it promotes uniform contact between gas and liquid phases and obtains the best distillation effect.

[0056] According to another embodiment of the present invention, a small distillation column is further provided, such as... Figure 2 The system includes a tower body 10, at least one packing layer 30, a reflux or feed liquid supply system, and a liquid distributor 20 installed above the packing layer 30. Specifically, a liquid feed pipe is installed on the side wall of the tower body 10. After the feed enters the tower, it bends downwards towards the center of the tower body, maintaining a distance of 50-200 mm from the top of the liquid distributor 20 to reduce the disturbance of free-fall impact on the liquid level and spray uniformity. The height of the steam riser 206 in the liquid distributor 20 is 100-400 mm. The lower surface of the liquid distributor 20 maintains a distance of 100-300 mm from the upper surface of the packing layer 30 to provide necessary redistribution and momentum decay space, allowing the droplets to complete velocity and direction rectification before entering the packing layer 30. In terms of implementation effect, the inlet conditions of the mass transfer zone are more controllable, and the risks of penetration and channeling are reduced.

[0057] The gas feed pipe is located in the middle or lower part of the tower body 10, and is pre-distributed using a cross-shaped main pipe with several gas branch pipes 131 arranged along it. In the specific design, the gas outlets are dispersed at certain intervals on the cross section, so that the gas has good cross-sectional uniformity when it reaches the bottom of the distribution plate, and matches the opening ratio and flow pattern of the distribution plate's steam riser array. In terms of implementation effect, the flow pattern of the gas phase before entering the mass transfer zone is more stable, the precursors of flooding and local flooding under load fluctuations are suppressed, and the operating flexibility and safety margin of the unit are improved.

[0058] Specifically, multiple sets of liquid distributors 20 and packing layers 30 can be arranged alternately along the column height. Each set consists of a liquid distributor 20 and the packing layer 30 below it, and includes 1 to 6 sets, thereby realizing the rhythm of "distribution-mass transfer-redistribution" within a limited column height.

[0059] In summary, this embodiment centers on a "flat-bottomed conical distribution plate + array-type first spray + sidewall second spray + multiple steam risers and overflow / steam riser caps + liquid supply / overflow leveling". Through the synergy of geometric array, leveling benchmark, and gas-liquid channels, it achieves coordinated near-wall wetting under a small column diameter, stable liquid level on the plate, and pre-uniform gas phase distribution. Without significantly increasing the column diameter and pressure drop, the device achieves higher uniform mass distribution and resistance to wall flow, significantly improves mass transfer efficiency and separation stability, and maintains a wider safe operating window under fluctuating load and reflux ratio conditions.

[0060] To provide a clearer understanding of the technical solution and effects of this utility model, a specific example is given below:

[0061] refer to Figure 1 The diagram illustrates a small distillation column. A mixed gas phase from an upstream unit contains a large amount of titanium tetrachloride, toluene, and a small amount of tetraethyl orthosilicate. This gas is uniformly injected into the column body 10 through a gas branch pipe 13 and a gas feed pipe 131. The column has a diameter of DN600. The gas feed pipe 13 is located in the column and has two layers of packing and two layers of liquid distributors on top of it, and one layer of liquid distributor and one layer of packing below it. The distance H1 between the bottom of each liquid distributor and the packing layer 30 is 150 mm.

[0062] The reflux liquid from the top vapor phase condensation is sprayed into the liquid distributor 20 through the liquid feed pipe 12. The center distance H3 between the liquid feed pipe 12 and the liquid distributor 20 is 100 mm, ensuring uniform distribution of the liquid within the liquid distributor 20. After being evenly dispersed through the first spray pipe 205 and the second spray pipe 203, the liquid comes into uniform contact with the gaseous material below in the packing layer 30, achieving distillation and purification of the material. The resulting gaseous product passes through the steam riser 206 of the liquid distributor 20, is distributed by the steam riser cap 207, and then exits the distillation column from the gas outlet 11 at the top of the column. The bottom liquid obtained after distillation is discharged through the bottom liquid outlet 14.

[0063] The liquid distributor 20 is provided with a distribution plate 201. The angle θ between the side wall 202 of the distribution plate and the bottom disk is 60°. At this time, the ratio L of the bottom disk diameter to the tower diameter is 0.72.

[0064] The height H2 of the steam riser pipe of the liquid distributor 20 is 150mm. An overflow port 208 is provided on the steam riser pipe 206, and its height is consistent with the inlet height of the first spray pipe and the second spray pipe to ensure uniform liquid distribution.

[0065] The first spray pipe 205 and the steam riser pipe 206 are arranged in a triangular pattern on the bottom disc. At this time, there are three steam riser pipes, and the opening rate of the steam riser pipe 206 is 30%.

[0066] The diameters of the first spray pipe 205 and the second spray pipe 203 are Φ12 and Φ6mm, respectively.

[0067] After separation and purification in the distillation column, the toluene content in the top gas product was 96.6%, which is basically consistent with the theoretical calculation of 96.8%.

[0068] The above-described embodiments are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the appended claims.

Claims

1. A liquid distributor for a small distillation column, characterized in that, include: The distribution plate installed inside the tower is composed of a flat-bottomed conical disc, with a horizontal base and an upwardly inclined annular sidewall; The first spray pipe is installed on the base of the distribution plate; A second spray pipe is fixed to the side wall of the distribution plate, and the second spray pipe is arranged around the circumference of the distribution plate; Steam riser pipes are installed on the distribution plate, and the steam riser pipes are provided with overflow ports; The liquid inlet of the first spray pipe, the liquid inlet of the second spray pipe, and the overflow outlet of the steam riser are at the same height to form a consistent liquid level when the distribution plate is working.

2. The liquid distributor according to claim 1, characterized in that, The outer diameter of the distribution tray base is 0.5 to 0.9 times the diameter of the distillation column, and the inclination angle of the side wall of the distribution tray relative to the base is 45° to 85°.

3. The liquid distributor according to claim 1, characterized in that, The first spray pipe consists of multiple pipes, which are evenly arranged in a triangular or square array on the base of the distribution plate.

4. The liquid distributor according to claim 1, characterized in that, The inlet and / or outlet of the first spray pipe has a serrated structure.

5. The liquid distributor according to claim 1, characterized in that, The outer diameter of the second spray pipe is 0.3 to 0.7 times that of the first spray pipe, and the second spray pipe is arranged continuously or in segments along the circumferential sidewall of the distribution plate.

6. The liquid distributor according to claim 1, characterized in that, The steam riser consists of multiple pipes, which are evenly arranged on the base of the distribution plate in a triangular or square array; the total flow cross-sectional area of ​​the steam riser accounts for 15% to 50% of the cross-sectional area of ​​the distillation column.

7. The liquid distributor according to claim 1, characterized in that, The upper end of the riser pipe is provided with an inverted triangular or conical riser cap, and an annular gap is formed between the riser cap and the riser pipe to evenly distribute the rising gas.

8. The liquid distributor according to claim 1, characterized in that, The overflow port of the steam riser pipe is an annular overflow edge, a notch, or a slotted structure; and / or, The height of the steam riser pipe is 100–400 mm; and / or, The diameter of the first spray pipe is 4 to 20 mm.

9. A small distillation column, characterized in that, include: The tower body, at least one packing layer, a reflux or feed liquid supply system, and a liquid distributor installed above the packing layer; wherein the liquid distributor is the liquid distributor according to any one of claims 1 to 8; The tower body is provided with a liquid feed pipe on its side wall. After entering the tower body, the liquid feed pipe bends downwards towards the center of the tower body. The distance between the downward bend of the pipe and the top of the liquid distributor is 50-200 mm. The distance between the lower surface of the liquid distributor and the upper surface of the packing layer is 100-300 mm. The lower part of the tower body is equipped with a gas feed pipe, which is arranged in a cross shape, and gas branch pipes are arranged at certain intervals on it.

10. The small-scale distillation column according to claim 9, characterized in that, The liquid distributor and the packing layer are arranged alternately in the height direction of the tower body, with 1 to 6 groups.

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