A parameter-controllable dividing wall distillation experimental device and a parameter adjustment method

Abstract

The application discloses a parameter-controllable dividing wall distillation experimental device and a parameter adjustment method, and belongs to the field of chemical separation technology. The device comprises a feeding system, a tower body, a condenser, a reboiler, a side-line extraction device, a gas-phase distribution device, a liquid-phase distribution device and a control system. The tower body is composed of a common rectification section, a common stripping section, and a pre-separation section and a main separation section which are independently arranged in parallel and form an equivalent dividing wall tower structure without a solid partition. The sections are detachable and are filled with packing. The number of theoretical plates, the equivalent dividing wall height and the position can be changed by adjusting the packing height and specifications. The control system adjusts the opening degree of the electric regulating valve, the flow guide switching state and the on-off time of the electromagnetic drive member to adjust the gas-phase distribution ratio, the liquid-phase distribution ratio, the reflux ratio and the side-line extraction rate. The application has a flexible structure and is suitable for the experimental research on the dividing wall distillation of different material systems and working conditions.

Description

Technical Field

[0001] This invention belongs to the field of chemical separation process technology, and relates to a partitioned distillation experimental device with adjustable parameters and a parameter adjustment method. Background Technology

[0002] Distillation is one of the most widely used technologies in the field of chemical separation, but it is also one of the most energy-intensive separation processes. Studies indicate that energy consumption in distillation accounts for over 90% of the total energy consumption in the entire separation field. Therefore, research on energy-saving technologies for distillation processes is of great significance to the sustainable development of the chemical industry. In recent years, partitioned-wall columns, as a highly efficient distillation enhancement device, have attracted increasing attention from researchers.

[0003] Traditional distillation technology often requires two columns in series to separate a mixture of three components (A, B, and C). While side-stream sampling reduces the number of equipment units, it significantly increases energy consumption, limiting its application. A partitioned-wall column, however, can separate light A, intermediate B, and heavy C components within a single column, and its energy consumption is lower compared to a two-column process. A partitioned-wall column is a thermally coupled distillation column that divides the column into four zones by adding a vertical partition: a common rectification section, a common stripping section, a pre-separation section, and a main separation section. In the actual separation process, the feedstock is added in the pre-separation section, where it is initially separated into two mixtures, AB and BC. Components AB enter the common rectification section, where components A and B are separated. Components BC then enter the common stripping section, where components B and C are separated. Component A can be collected from the top of the column, component B from the side stream, and component C from the bottom of the column. Figure 1 As shown in the diagram. In this process, the liquid phase descending from the common rectification section is distributed to the pre-separation section and the main separation section in a certain proportion, serving as liquid phase reflux in these sections; the gas phase rising from the common stripping section is also distributed to the pre-separation section and the main separation section in a proportional manner, serving as gas phase circulation. Only one partition wall column is needed to achieve the separation effect of two columns in series. Compared to a two-column process, the partition wall column not only reduces the number of columns, reboilers, condensers, and other equipment, but also reduces the floor space required and lowers operating costs.

[0004] The existing partition tower still has some problems in its application in small-scale experiments: (1) The partition structure is fixed and the parameters cannot be flexibly changed. Most existing partition tower experimental devices are made by welding a partition inside the distillation column. This structure results in fixed and unadjustable parameters such as partition height and partition position. In addition, the number of trays in different separation sections is also difficult to adjust. This means that a set of equipment can only be adapted to a single separation condition. If the raw material system is changed, the tower body needs to be re-customized, resulting in poor experimental versatility.

[0005] (2) Difficulty in adjusting the gas-phase distribution ratio. The gas-phase distribution ratio refers to the proportion of the gas rising from the common stripping section entering the pre-separation section and the main separation section. In current industrial applications or experimental research of partitioned column distillation, the gas-phase distribution ratio is mostly adopted in a free distribution manner. The specific ratio is related to parameters such as pressure drop, column diameter, and liquid flow rate of the two separation sections. A suitable gas-phase distribution ratio can not only improve the purity of the product but also reduce the energy consumption of the distillation process. How to measure and adjust this ratio has become a major problem in the application of partitioned column technology. Some researchers have proposed a method of drawing the gas from both sides of the partition out of the column for redistribution and then returning it to both sides of the partition. However, this method is unstable, and the resistance to gas flow is large due to multiple valves and bends. In addition, the problem of heat preservation also needs to be considered. In actual experiments, it is usually difficult to accurately control the gas-phase distribution ratio. In addition, some related studies have proposed a method of using the Coanda effect of fluids to assist in controlling the gas flow rate and thus controlling the gas-phase distribution ratio. This method requires a specially designed tray structure. During the experiment, high-speed gas is pumped into both ends of the tray. Once inside the column, the high-speed gas drives the existing gas upwards. By controlling the flow rate of the high-speed gas, the flow rate of gas entering different separation sections can be controlled, thereby controlling the gas-phase distribution ratio. This method can accurately control the gas-phase distribution ratio, but extensive experiments are required before distillation to determine the relationship between the high-speed gas flow rate and the gas-phase distribution ratio. The process is quite cumbersome, and the complex structure of the special tray makes it unsuitable for use on small-diameter experimental setups. Summary of the Invention

[0006] This invention addresses the problems of poor versatility, difficulty in adjusting the gas-phase distribution ratio, and limited extraction modes in existing partitioned distillation experimental apparatuses by providing a parameter-adjustable partitioned distillation experimental apparatus and parameter adjustment method. The invention employs a non-physical partitioned equivalent partitioned column structure consisting of a common rectification section, a common stripping section, and two independent and parallel pre-separation sections and a main separation section. Each column section is a packed column, and the theoretical plate number, equivalent partitioned wall height, and equivalent partitioned wall position can be changed by adjusting the packing height and packing specifications. Simultaneously, a gas-phase distribution device, a liquid-phase distribution device, and a side-stream extraction device are separately provided. A control system precisely adjusts the gas-phase distribution ratio, liquid-phase distribution ratio, and side-stream extraction rate, improving the accuracy and repeatability of experimental data. This allows the same experimental apparatus to adapt to the needs of partitioned distillation experiments under different material systems and operating conditions.

[0007] According to a first aspect of the present invention, a partitioned distillation experimental apparatus with adjustable parameters is provided, comprising a feed system, a column, a condenser, a reboiler, a side stream extraction device, a gas phase distribution device, a liquid phase distribution device, and a control system. The tower body includes a common rectification section, a pre-separation section, a main separation section, and a common stripping section arranged along the material separation direction. The pre-separation section and the main separation section are two independent and parallel tower sections. The upper ends of the pre-separation section and the main separation section are respectively connected to the common rectification section, and the lower ends are respectively connected to the common stripping section, so as to jointly form an equivalent partition wall tower structure without a solid partition. The pre-separation section is provided with a feed inlet connected to the feeding system, the main separation section is provided with a side-stream outlet connected to the side-stream outlet device, the condenser is connected to the common rectification section, and the reboiler is connected to the common stripping section. The common rectification section, the pre-separation section, the main separation section, and the common stripping section are all packed column sections. The packing height in at least some of the packed column sections can be independently adjusted to adjust the theoretical plate number, equivalent partition height, and equivalent partition position of the column body. The liquid phase distribution device is disposed between the common rectification section, the pre-separation section, and the main separation section, and is used to adjust the liquid phase distribution ratio flowing from the common rectification section to the pre-separation section and the main separation section; The gas phase distribution device is disposed between the common stripping section, the pre-separation section, and the main separation section, and is used to adjust the gas phase distribution ratio flowing from the common stripping section to the pre-separation section and the main separation section; The control system is connected to the side-line extraction device, the gas phase distribution device, and the liquid phase distribution device respectively, and is used to adjust the side-line extraction rate, the gas phase distribution ratio, and the liquid phase distribution ratio.

[0008] In some technical solutions, the common distillation section, the pre-separation section, the main separation section, and the common stripping section are detachably connected by flanges or chucks, and the packing in each packed column section can be disassembled, replaced, or added or removed to adjust the packing height and / or packing specifications of the corresponding packed column section.

[0009] In some technical solutions, the packing height of the pre-separation section and the main separation section is used to determine the equivalent partition wall height, the combination of the packing height of the common rectification section and the common stripping section is used to determine the position of the equivalent partition wall, and the theoretical number of plates of each packed column section is determined according to the corresponding packing height and the equivalent plate height of the packing used.

[0010] In some technical solutions, the gas phase distribution device includes a gas phase channel that is connected to the pre-separation section and the main separation section respectively, a liquid phase channel for supplying liquid phase into the common stripping section, an overflow weir disposed in the liquid phase channel, an electric regulating valve disposed in at least one of the gas phase channels, and a differential pressure detector for detecting the gas phase flow state of the pre-separation section and the main separation section. The control system is configured to adjust the opening of the electric regulating valve according to the detection result of the differential pressure detector and the pre-established correspondence between the valve opening and the gas phase flow rate, so that the gas phase distribution ratio reaches the set value.

[0011] In some technical solutions, the liquid phase distribution device includes a first liquid accumulation plate, a first flow channel and a second flow channel respectively connected to the pre-separation section and the main separation section, and an electromagnetically driven flow switching component; The flow guiding switching component can switch between a first working state and a second working state, so that the liquid phase in the first liquid accumulation pan flows into the pre-separation section and the main separation section through the first flow guiding channel and the second flow guiding channel, respectively. The control system adjusts the liquid phase distribution ratio by adjusting the ratio of the duration of the first working state to that of the second working state.

[0012] In some technical solutions, the side-line extraction device includes a second liquid collection plate, a downcomer, a float valve through which the gas supply phase passes, an extraction guide that can switch between extraction and non-extraction positions, a side-line extraction outlet corresponding to the extraction guide, and an electromagnetic drive for driving the extraction guide. The control system adjusts the ratio of the energization time to the de-energization time of the electromagnetic drive component, thereby adjusting the time ratio during which the extraction guide component is in the extraction position, and thus adjusting the side-line extraction rate.

[0013] In some technical solutions, the pre-separation section is provided with multiple switchable feed inlets along the height direction, and the main separation section is provided with multiple switchable side feed outlets along the height direction. The feed position can be adjusted by switching the feed inlet at different heights, the side outlet position can be adjusted by switching the side outlet at different heights, and the feed position and / or the side outlet position can also be adjusted by adjusting the packing height on the upper and lower sides of the corresponding feed inlet or side outlet.

[0014] Some technical solutions also include a reflux ratio distributor, a temperature sensor, a pressure sensor, a level sensor, and a vacuum system; The reflux ratio distributor includes an oscillating guide that can switch between a reflux position and a tower top extraction position, and an electromagnetic coil for driving the oscillating guide. The control system adjusts the reflux ratio by adjusting the time ratio of the oscillating guide in the reflux position and the tower top extraction position. The temperature sensor and the pressure sensor are arranged along the height of the tower body, the liquid level sensor is arranged in the reboiler and / or the product storage tank, and the vacuum system is connected to at least one of the condenser, the top product storage tank, the side-stream product storage tank and the bottom product storage tank. The diameter of the tower body is less than 300 mm.

[0015] According to a second aspect of the present invention, a method for adjusting experimental parameters in partitioned distillation is further provided, employing the above-described partitioned distillation experimental apparatus, comprising the following steps: Based on the material system to be separated and the target separation requirements, the required number of theoretical plates for the common rectification section, pre-separation section, main separation section and common stripping section are determined respectively. By adjusting the packing height of the corresponding packed column sections, the number of theoretical plates, equivalent partition wall height and equivalent partition wall position of the partition wall rectification experimental device are set. Select the feed position of the pre-separation section and the side-line extraction position of the main separation section according to the material system to be separated; The material to be separated is introduced into the pre-separation section, and the material in the bottom of the column is heated by the reboiler and the gas phase at the top of the column is condensed by the condenser. The gas phase distribution ratio entering the pre-separation section and the main separation section from the common stripping section is adjusted by the gas phase distribution device, the liquid phase distribution ratio entering the pre-separation section and the main separation section from the common rectification section is adjusted by the liquid phase distribution device, and the side stream extraction rate is adjusted by the side stream extraction device. After reaching a stable distillation state, light component products, intermediate component products, and heavy component products are collected from the top, side stream, and bottom of the column, respectively.

[0016] In some technical solutions, the adjustment of the gas phase distribution ratio includes: detecting the pressure difference or gas phase flow parameters between the pre-separation section and the main separation section, determining the actual gas phase distribution ratio based on the detection results, and adjusting the opening of the electric regulating valve based on the deviation between the actual gas phase distribution ratio and the target gas phase distribution ratio. The adjustment of the liquid phase distribution ratio includes: adjusting the ratio of the duration of the liquid phase distribution device under different flow conditions, so that the liquid phase flows into the pre-separation section and the main separation section respectively according to the target liquid phase distribution ratio; The side-line extraction rate and return ratio are adjusted by adjusting the ratio of the energizing time to the de-energizing time of the corresponding electromagnetic drive component.

[0017] This device employs a segmented tower body combined with an equivalent structure without solid partitions, enabling the reconstruction of the partition tower's structural parameters. Simultaneously, liquid phase distribution and gas phase distribution are controlled by altering the time ratio and cross-sectional area, respectively. The flexibility of the tower's structural and operational parameters allows the entire device to adapt to various partition tower structures and different operating conditions.

[0018] The present invention, by employing the above technical solution, has at least the following beneficial effects: 1. Precise Adjustment of Multiple Parameters: This device enables continuous and accurate adjustment of key parameters such as the number of theoretical plates, equivalent partition wall height, equivalent partition wall position, gas-liquid phase distribution ratio, reflux ratio, and feed / collection position. This solves the problems of low parameter control precision and difficulty in controlling the gas-phase distribution ratio in existing partition wall columns, significantly improving the accuracy and repeatability of experimental data. Furthermore, the partition wall column sections adopt a detachable modular design, allowing for disassembly and replacement according to specific experimental requirements. One set of equipment can complete experimental studies on various raw material systems, significantly reducing experimental costs and improving the device's versatility.

[0019] 2. Simple structure and low cost: It adopts a structurally equivalent partitioned tower structure, eliminating the need for welding solid partitions and avoiding heat and gas exchange on both sides of the partition; by using an electric regulating valve and an electromagnetically driven flow switching component to control the gas-liquid phase distribution ratio, there is no need to customize complex special tower trays. The overall structure of the device is simple, the manufacturing cost is low, and it is suitable for laboratory pilot-scale research.

[0020] 3. Significant energy saving effect: Only one adjacent tower is needed to achieve the separation effect of traditional double tower. Compared with the double tower process, it can save investment in auxiliary equipment such as reboilers, condensers, transfer pumps and pipelines, reduce the footprint of the unit, and reduce process energy consumption by more than 20%, which has good application prospects. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the partitioned distillation principle provided in an embodiment of the present invention; Figure 2 A schematic diagram of the experimental apparatus for adjustable partitioned distillation provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the side-line extraction device provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the gas phase distribution device provided in an embodiment of the present invention.

[0022] The meanings of the symbols marked in the figure are as follows: 1. Condenser; 2. Reflux distributor; 3. Top product storage tank; 4. Instantaneous sampling port; 5. Common rectification section; 6. Liquid phase distribution device; 7. Pre-separation section; 8. Main separation section; 9. Side stream product storage tank; 10. Gas phase distribution device; 11. Feed pump; 12. Raw material tank; 13. Common stripping section; 14. Reboiler; 15. Condenser; 16. Bottom product storage tank; 17. Float valve; 18. Guide pipe; 19. Outlet guide; 20. Electromagnetic drive; 21. Side stream outlet; 22. Overflow weir; 23. Electric regulating valve; 24. Liquid phase channel; 25. Gas phase channel; 26. Opening controller; 27. Differential pressure detector; T1~T18. Temperature sensor. Detailed Implementation

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0024] To keep the drawings concise, each figure only schematically shows the parts relevant to the invention, and these do not represent the actual structure of the product. Furthermore, to facilitate understanding, in some figures, only one of 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."

[0025] 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.

[0026] 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 communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] 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.

[0028] Example 1 like Figure 1 and Figure 2 As shown, this embodiment provides a parameter-adjustable partitioned distillation experimental apparatus, including a feed system, a column body, a condenser 1, a reboiler 14, a side stream extraction device, a gas phase distribution device 10, a liquid phase distribution device 6, a reflux ratio distributor 2, a vacuum system, and a control system.

[0029] The column body includes a common rectification section 5, a pre-separation section 7, a main separation section 8, and a common stripping section 13. The pre-separation section 7 and the main separation section 8 are two independent and parallel column sections. The upper ends of the pre-separation section 7 and the main separation section 8 are connected to the common rectification section 5, and the lower ends are connected to the common stripping section 13, thus forming an equivalent partitioned wall column structure without a solid partition.

[0030] During distillation, the materials to be separated enter the column through the pre-separation section 7, where preliminary separation takes place. Relatively volatile components rise with the vapor phase into the common rectification section 5, while relatively less volatile components descend with the liquid phase into the common stripping section 13. The main separation section 8 further separates the descending liquid phase from the common rectification section 5 and the rising vapor phase from the common stripping section 13. Intermediate components are collected from the side outlet 21 of the main separation section 8, light components are collected from the top of the column, and heavy components are collected from the bottom of the column.

[0031] Since the pre-separation section 7 and the main separation section 8 are two independent column sections instead of solid partitions in the same column shell, the possibility of heat exchange and gas phase crossflow between the two separation sections can be reduced while realizing the function of partition distillation. It also makes it easier to disassemble, fill and adjust the different column sections separately.

[0032] In the specific implementation, the common rectification section 5, the pre-separation section 7, the main separation section 8, and the common stripping section 13 are all packed column sections, and adjacent column sections are detachably connected by flanges or chucks. Each packed column section is filled with rectification packing, which can be bulk packing or structured packing. In a preferred embodiment, the rectification packing uses Westerner rings, for example, 2 mm Westerner rings.

[0033] The packing material in each packed column section can be disassembled, replaced, or added to, thereby adjusting the packing height and specifications of the corresponding section. The theoretical number of trays in each section can be determined based on the packing height and the equal tray height of the packing material used. By changing the packing height of a section, the theoretical number of trays in that section can be altered to meet the separation requirements of different material systems.

[0034] In the specific design, the effective packing height of the pre-separation section 7 and the main separation section 8 is used to determine the equivalent partition wall height in the equivalent structure without solid partitions. Increasing the packing height of the pre-separation section 7 and the main separation section 8 will increase the equivalent partition wall height accordingly; decreasing the packing height of the pre-separation section 7 and the main separation section 8 will decrease the equivalent partition wall height accordingly.

[0035] The combination of packing heights in the common rectification section 5 and the common stripping section 13 is used to determine the position of the equivalent partition wall. By adjusting the packing heights of the common rectification section 5 and the common stripping section 13, the height positions of the pre-separation section 7 and the main separation section 8 relative to the entire column can be changed. For example, with the total effective separation height of the column remaining essentially unchanged, increasing the packing height of the common rectification section 5 and correspondingly decreasing the packing height of the common stripping section 13 will lower the position of the equivalent partition wall; decreasing the packing height of the common rectification section 5 and correspondingly increasing the packing height of the common stripping section 13 will raise the position of the equivalent partition wall.

[0036] Therefore, by adjusting the packing height of the four packed sections separately, the theoretical plate number, equivalent partition wall height, and equivalent partition wall position can be adjusted in the same experimental setup to simulate partitioned distillation columns with different structural parameters.

[0037] The feeding system is used to convey the material to be separated to the pre-separation section 7. In specific implementation, the feeding system includes a raw material tank 12 and a feed pump 11. The raw material tank 12 is connected to the feed inlet of the pre-separation section 7 through a feed pipeline. The feed pump 11 is installed on the feed pipeline and is used to regulate the feed flow rate of the material to be separated.

[0038] The pre-separation section 7 has multiple feed inlets along its height, and each feed inlet can selectively connect to the feeding system. In a specific design, the pre-separation section 7 can have an upper feed inlet, a middle feed inlet, and a lower feed inlet. By switching feed inlets at different heights, the feeding position can be adjusted in stages.

[0039] When further adjustments to the feed position are needed, the packing height above and below the selected feed inlet can be changed while keeping the total packing height of the pre-separation section 7 essentially unchanged. For example, reducing the packing height above the feed inlet and increasing the packing height below the feed inlet can move the feed position upward relative to the effective separation zone of the pre-separation section 7; conversely, adjusting in the opposite direction can move the feed position downward relative to the effective separation zone.

[0040] The main separation section 8 is provided with multiple side-line extraction outlets 21 along the height direction. In specific implementation, the main separation section 8 may be provided with upper side-line extraction outlets, middle side-line extraction outlets and lower side-line extraction outlets. By switching the side-line extraction outlets 21 at different heights, the side-line extraction position of the intermediate components can be adjusted in stages.

[0041] In the specific design, the position of the side stream extraction point relative to the effective separation zone of the main separation section 8 can be further adjusted by changing the packing height above and below the selected side stream extraction outlet 21. Thus, both the feed position and the side stream extraction position can be adjusted according to the material composition, feed status, and target separation requirements.

[0042] Condenser 1 is connected to the top of the common rectification section 5 and is used to condense the overhead gas phase discharged from the common rectification section 5. In specific implementations, condenser 1 can be a vertical coil condenser, a shell-and-tube condenser, or other condensers suitable for small-scale distillation experimental apparatus, and the cooling medium can be water or other cooling media.

[0043] The liquid condensed by condenser 1 is partially returned to the common rectification section 5 via reflux distributor 2, and the other part enters the top product storage tank 3 as the top product. Instantaneous sampling port 4 can be installed in the top product pipeline for sampling and analysis of the top product.

[0044] The reboiler 14 is connected to the bottom of the common stripping section 13 and is used to heat the bottom material and generate an upward-flowing gas phase. In a specific implementation, the reboiler 14 can be a batch reboiler and equipped with an electric heating mantle or other heating device. The heavy component product in the bottom of the column is condensed by the condenser 15 and then enters the bottom product storage tank 16.

[0045] like Figure 3 As shown, the side stream extraction device is located in the main separation section 8 and is used to control the side stream extraction of intermediate components. The side stream extraction device includes a second liquid collection pan, a downcomer, a float valve 17, a guide pipe 18, an extraction guide component 19, a side stream extraction outlet 21, and an electromagnetic drive component 20.

[0046] The second accumulator tray is used to collect the downward-flowing liquid phase within the main separation section 8. A downcomer connects to the second accumulator tray to allow the liquid phase to continue flowing downwards into the tower when no side-stream sampling is being performed. A float valve 17 is installed on the second accumulator tray to allow the rising gas phase to pass through and to reduce the obstruction of the second accumulator tray to the gas phase flow within the tower. A guide pipe 18 connects to the second accumulator tray and extends downwards from it.

[0047] The extraction guide 19 is located below the outlet of the guide pipe 18 and can switch between the extraction position and the non-extraction position. In a specific design, the extraction guide 19 can be a funnel with magnetic components or a funnel that can be attracted by magnetic force. When the electromagnetic drive 20 is energized, the electromagnetic drive 20 generates magnetic force and drives the extraction guide 19 to move to the extraction position, so that at least part of the liquid phase in the second liquid collection plate flows through the extraction guide 19 to the side line extraction outlet 21; when the electromagnetic drive 20 is de-energized, the extraction guide 19 returns to the non-extraction position, so that the liquid phase continues to flow downward through the downcomer.

[0048] The control system adjusts the average extraction rate of the sideline liquid phase by regulating the energizing and de-energizing time of the electromagnetic drive component 20, thereby controlling the time ratio between the extraction guide component 19 and the extraction position. In a preferred embodiment, the sideline extraction rate can be adjusted by changing the proportion of the energizing time to the entire operating cycle while keeping the operating cycle essentially constant.

[0049] like Figure 2 As shown, the liquid phase distribution device 6 is located between the lower part of the common distillation section 5 and the upper part of the pre-separation section 7 and the main separation section 8, and is used to distribute the liquid phase flowing downward from the common distillation section 5 to the pre-separation section 7 and the main separation section 8 according to a set ratio.

[0050] The liquid phase distribution device 6 includes a first liquid collection tray, a first flow guiding channel, a second flow guiding channel, and an electromagnetically driven flow guiding switching component. The first liquid collection tray is used to collect the liquid phase flowing down from the common rectification section 5. The first flow guiding channel is connected to the pre-separation section 7, and the second flow guiding channel is connected to the main separation section 8.

[0051] The flow guiding switching component can switch between a first operating state and a second operating state. In the first operating state, the liquid phase in the first liquid accumulation pan mainly flows into the pre-separation section 7 through the first flow guiding channel; in the second operating state, the liquid phase in the first liquid accumulation pan mainly flows into the main separation section 8 through the second flow guiding channel.

[0052] In practice, the flow-guiding switching device can be a swing funnel or a switching valve with the same flow-guiding switching function. The flow-guiding switching device is connected to the control system, which adjusts the liquid phase distribution ratio entering the pre-separation section 7 and the main separation section 8 by controlling the ratio of the duration of the flow-guiding switching device in the first working state and the second working state.

[0053] In a preferred implementation, the flow guide switching component periodically switches between two working states and achieves proportional control of the small flow rate liquid phase through time allocation, thereby avoiding the problem of being easily affected by flow fluctuations when using continuous flow regulation in small experimental devices.

[0054] like Figure 4 As shown, the gas phase distribution device 10 is located between the upper part of the common stripping section 13 and the lower part of the pre-separation section 7 and the main separation section 8, and is used to distribute the rising gas phase in the common stripping section 13 to the pre-separation section 7 and the main separation section 8 according to a set ratio.

[0055] The gas phase distribution device 10 includes a gas phase channel 25 that is connected to the pre-separation section 7 and the main separation section 8 respectively, a liquid phase channel 24 for the descending liquid phase to enter the common stripping section 13, an overflow weir 22 disposed in the liquid phase channel 24, an electric regulating valve 23 disposed in at least one gas phase channel 25, an opening controller 26, and a differential pressure detector 27.

[0056] The liquid phase channel 24 allows the liquid phase flowing downward from the pre-separation section 7 and the main separation section 8 to enter the common stripping section 13. The overflow weir 22 is used to maintain a liquid seal or a specified liquid phase flow state within the liquid phase channel 24 to reduce the direct passage of rising gas phase through the liquid phase channel 24, so that the gas phase mainly enters the pre-separation section 7 and the main separation section 8 through the gas phase channel 25.

[0057] The electric regulating valve 23 can be an electric butterfly valve. By changing the opening degree of the electric regulating valve 23, the effective flow area and gas flow resistance of the corresponding gas phase channel 25 are changed, thereby adjusting the gas phase flow ratio entering the pre-separation section 7 and the main separation section 8.

[0058] In the specific design, an electric regulating valve 23 can be installed in each of the two gas phase channels 25 that are connected to the pre-separation section 7 and the main separation section 8, or an electric regulating valve 23 can be installed in one of the gas phase channels 25 and the other gas phase channel 25 can be used as the reference channel.

[0059] The differential pressure detector 27 is used to detect the gas phase flow differential pressure corresponding to the pre-separation section 7 and the main separation section 8. Based on the detection result of the differential pressure detector 27 and the predetermined correspondence between the opening degree of the electric regulating valve 23 and the gas phase flow rate, the control system obtains or judges the actual gas phase distribution state, and adjusts the opening degree of the electric regulating valve 23 through the opening degree controller 26 to make the actual gas phase distribution ratio approach the set gas phase distribution ratio.

[0060] In practice, the relationship between pressure difference and gas flow rate under different opening degrees of the electric regulating valve can be calibrated before the device is used, and the calibration results are stored in the control system. During the distillation experiment, the control system adjusts the opening degree of the electric regulating valve 23 according to the real-time pressure difference detection results to monitor and adjust the gas phase distribution ratio. The formula for calculating the gas phase distribution ratio based on the ratio of pressure differences is shown in Equation 1, where... Represents the pressure difference in the pre-separation section. Represents the pressure difference in the main separation section. This represents the gas phase distribution ratio.

[0061] (1) The reflux ratio distributor 2 is located between the condenser 1 and the common rectification section 5, and is used to adjust the reflux flow rate and the top product flow rate of the condensate. The reflux ratio distributor 2 includes an oscillating guide that can switch between the reflux position and the top product position, and an electromagnetic coil for driving the oscillating guide.

[0062] When the oscillating guide is in the reflux position, the condensate returns to the common rectification section 5; when the oscillating guide is in the top collection position, the condensate enters the top product storage tank 3. The control system adjusts the reflux ratio of the distillation experimental unit by regulating the ratio of the duration of the oscillating guide in the reflux position to the duration of the top collection position.

[0063] In practice, the oscillating guide can be an oscillating funnel with a magnetic core. The electromagnetic coil is energized and de-energized according to a preset cycle, causing the oscillating funnel to deflect periodically between the return direction and the extraction direction.

[0064] The control system in this embodiment can be a PLC control system. The control system is connected to the feed pump 11, the cooling medium regulating component of the condenser 1, the heating device of the reboiler 14, the reflux ratio distributor 2, the liquid phase distributor 6, the gas phase distributor 10, and the side-stream extraction device.

[0065] Multiple temperature sensors T1 to T18 and pressure sensors are installed along the height of the column to detect the temperature and pressure at different locations in the common rectification section 5, pre-separation section 7, main separation section 8, and common stripping section 13. The number and location of the temperature sensors can be adjusted according to the column height, the number of packing sections, and experimental monitoring requirements, and are not limited to the number shown in the figure.

[0066] A liquid level sensor can be installed in at least one of the reboiler 14, the top product storage tank 3, the side-stream product storage tank 9, and the bottom product storage tank 16 to monitor the liquid level in the corresponding container. The control system receives temperature, pressure, differential pressure, and liquid level detection signals, and displays and records the corresponding experimental parameters.

[0067] In the specific design, the control system can adjust the opening of the electric regulating valve 23 according to the set gas phase distribution ratio, adjust the duration of the flow guide switching component under different working states according to the set liquid phase distribution ratio, adjust the on / off time of the extraction guide component 19 according to the set side-line extraction rate, and adjust the working cycle of the reflux ratio distributor 2 according to the set reflux ratio.

[0068] In a preferred implementation, the control system can also provide feedback adjustment to the electric regulating valve 23, the liquid phase distribution device 6, the side stream extraction device, and the reflux ratio distributor 2 based on the deviation between the detected parameters and the set parameters, so as to improve the stability and repeatability of the experimental conditions.

[0069] The vacuum system in this embodiment is used to operate the distillation apparatus under reduced pressure. At least one of the following is provided with a vacuum interface: the top of the condenser 1, the top product storage tank 3, the side-stream product storage tank 9, and the bottom product storage tank 16. The vacuum interface is connected to the vacuum unit via a vacuum pipeline.

[0070] In practice, the vacuum system can be connected to multiple product storage tanks and condenser 1 simultaneously, and the set operating pressure inside the column is maintained through a vacuum regulating valve. By reducing the operating pressure inside the column, the boiling point of the material to be separated can be lowered, enabling the device to be used for distillation experiments of high-boiling-point materials or heat-sensitive materials.

[0071] In a preferred embodiment, the column body is made of stainless steel and has a diameter of less than 300 mm to form a small-scale partitioned distillation experimental apparatus suitable for laboratory pilot studies. The connecting pipelines between each column section, product storage tank, condenser 1, and reboiler 14 can be equipped with sealing and insulation structures according to the requirements of atmospheric or vacuum distillation.

[0072] When using the above-mentioned apparatus for parameter adjustment, firstly, based on the relative volatility, composition, and target product purity of the material system to be separated, determine the required number of theoretical plates for the common rectification section 5, pre-separation section 7, main separation section 8, and common stripping section 13. Then, based on the equivalent plate height of the packing material used, determine the packing height for each section, and set the number of theoretical plates, equivalent partition height, and equivalent partition position by increasing, decreasing, or replacing the packing material.

[0073] Based on the composition and feeding state of the materials to be separated, select the feed inlet at the corresponding height in the pre-separation section 7, and select the side outlet 21 at the corresponding height in the main separation section 8 according to the separation position of the target intermediate component. If further position adjustments are required, the packing height on both sides above and below the corresponding feed inlet or side outlet 21 can be changed.

[0074] After the device parameters are set, the feed pump 11 transports the material to be separated in the raw material tank 12 to the pre-separation section 7. The reboiler 14 heats the material in the bottom of the column and generates rising gas phase. The condenser 1 condenses the top gas phase discharged from the common rectification section 5.

[0075] The control system sets the reflux ratio, gas phase distribution ratio, liquid phase distribution ratio, and side stream extraction rate according to the target operating conditions. The liquid phase distribution device 6 distributes the liquid phase descending from the common rectification section 5 to the pre-separation section 7 and the main separation section 8 according to the set liquid phase distribution ratio; the gas phase distribution device 10 distributes the gas phase rising from the common stripping section 13 to the pre-separation section 7 and the main separation section 8 according to the set gas phase distribution ratio; the side stream extraction device extracts intermediate components from the main separation section 8 at a set rate.

[0076] After the temperature, pressure, liquid level, and product composition within the column reach a stable state, the light component product, intermediate component product, and heavy component product are collected from the top, side stream, and bottom of the column, respectively. After completing an experiment with one material system, the same experimental setup can be adapted to other material systems or other distillation conditions by changing the packing height, packing specifications, feed location, side stream exit location, and gas-liquid phase distribution parameters of each column section.

[0077] Example 2: Device setup, parameter calibration and overall debugging This embodiment is used to complete the construction of the adjacent tower experimental device, the calibration of key parameters and the overall debugging, laying the foundation for subsequent experiments under different working conditions.

[0078] Setup and Airtightness Testing: In this embodiment, a common rectification section, pre-separation section, main separation section, and common stripping section are constructed in the adjacent column by segmenting and filling with 2mm Westerne ring packing. A vertical shell-and-tube condenser is installed at the top of the column, and a reboiler with an external electric heating jacket is installed at the bottom. A side-stream sampling device consisting of a collection tray, downcomer, float valve, funnel, and electromagnetic coil is installed on the sidestream. Vacuum interfaces are reserved at the top of the condenser, the top of the column, the sidestream, and the product tank at the bottom. Temperature and pressure sensors are installed in the column body, and level sensors are installed in the bottom and product tank. The entire system is connected to a PLC control system. After the system is set up, an airtightness test is first performed: a vacuum unit is connected, and the system pressure is reduced to -0.08MPa. The pressure is held for 30 minutes, and the pressure rise does not exceed 0.005MPa, indicating that the unit has good airtightness.

[0079] Key parameter calibration and control debugging: First, the gas-phase distribution ratio is calibrated. An electric butterfly valve is installed at the top of the common stripping section, with differential pressure gauges on both sides of the valve. The differential pressure gauge on the pre-separation section side is ΔP1, and the differential pressure gauge on the main separation section side is ΔP2. The reboiler heater is turned on to generate an upward gas flow. The butterfly valve opening is adjusted, and the differential pressure gauge readings at different openings are recorded. The corresponding gas-phase distribution ratio is calculated according to the formula, establishing a curve showing the relationship between the butterfly valve opening and the gas-phase distribution ratio. After calibration, during the actual distillation process, the PLC control system collects the differential pressure data in real time and compares it with the target setpoint. When there is a deviation between the actual value and the target value, the butterfly valve opening is automatically adjusted to stabilize the gas-phase distribution ratio within the target range. Subsequently, the reflux ratio and liquid phase distribution ratio were adjusted. A reflux ratio controller consisting of a oscillating funnel with a magnetic core and an electromagnetic coil was installed at the top of the column. By controlling the on and off state of the coil, the funnel was periodically deflected. The ratio of the on-time to the off-time was set to control the condensate to reflux or be collected according to the set ratio, so as to achieve precise control of the reflux ratio. At the same time, by adjusting the solenoid valve at the bottom of the common rectification section, the liquid phase flow direction was changed, and the liquid phase distribution ratio between the pre-separation section and the main separation section was controlled to complete the calibration of the liquid phase distribution ratio.

[0080] Verification of commissioning results: After completing the above calibration and commissioning, key parameters of the device, such as the number of trays (adjusted by packing height), baffle position (adjusted by packing height in the pre-separation section / main separation section), gas-liquid phase distribution ratio, reflux ratio, and feed / collection position, can be continuously and accurately adjusted. The PLC control system can achieve stable closed-loop control of the parameters, laying the foundation for subsequent experimental verification under different operating conditions.

[0081] Example 3: Separation experiment of benzene / toluene / xylene ternary mixture under normal pressure conditions This embodiment uses the benzene / toluene / xylene ternary system as a typical separation target to verify the separation performance and energy-saving characteristics of the device under normal pressure conditions.

[0082] Experimental conditions and parameter settings: The feedstock was a ternary mixture of benzene (A), toluene (B), and xylene (C) in a mass ratio of 3:4:3. The feed flow rate was 10 g / min, and the apparatus was operated under atmospheric pressure. Key parameters were set as follows: the packing height in the common rectification section was 900 mm, the packing height in both the pre-separation and main separation sections was 200 mm, and the packing height in the common stripping section was 500 mm; the reflux ratio was set to 4:1; the liquid phase distribution ratio was 1:2 (pre-separation section: main separation section); the gas phase distribution ratio was 1:1 (pre-separation section: main separation section); the feedstock entered from the middle of the pre-separation section, and the side stream outlet was located in the middle of the main separation section.

[0083] Experimental Results and Apparatus Performance Verification: After 2 hours of stable operation, the mass fraction of benzene in the top product was measured to be 99.2%, the mass fraction of toluene in the side-stream product was 98.7%, and the mass fraction of xylene in the bottom product was 99.1%, demonstrating efficient separation of the ternary mixture. Compared with the traditional dual-tower distillation process, the reboiler energy consumption in this embodiment was reduced by approximately 22%, verifying the energy-saving characteristics of the apparatus. This embodiment shows that the partitioned-wall column experimental apparatus can achieve efficient separation of ternary mixtures under atmospheric pressure conditions, and the apparatus parameters are highly adjustable, with stable separation performance, meeting the distillation experimental requirements of conventional systems.

[0084] Example 4: Separation experiment of acetic acid / propionic acid / butyric acid ternary mixture under reduced pressure This embodiment takes the thermosensitive ternary system of acetic acid / propionic acid / butyric acid as the research object, and verifies the adaptability and operating flexibility of the device to thermosensitive materials through vacuum distillation.

[0085] Experimental conditions and parameter settings: The raw material was a ternary mixture of acetic acid (A), propionic acid (B), and butyric acid (C) in a mass ratio of 3:4:3, with a feed flow rate of 10 g / min. The apparatus was connected to a vacuum unit via a vacuum interface to maintain the system operating pressure at -0.03 MPa and to reduce the operating temperature to avoid decomposition of heat-sensitive organic acids. Key parameters of the apparatus were set as follows: the packing height in the common rectification section was 400 mm, the packing height in the pre-separation section and the main separation section was 900 mm, and the packing height in the common stripping section was 500 mm; the reflux ratio was set to 5:1; the liquid phase distribution ratio was 1:2; the gas phase distribution ratio was controlled by a butterfly valve and calculated from the pressure difference, with the gas phase distribution ratio between the pre-separation section and the main separation section being approximately 1:1; the raw material was fed from the top of the pre-separation section, and the side feed outlet was located in the middle of the main separation section; the reboiler power was set to 70% of the rated power, and the heating temperature was reduced to avoid material decomposition.

[0086] Experimental Results and Apparatus Performance Verification: After 3 hours of stable operation, the mass fraction of acetic acid in the top product was measured to be 95.6%, the mass fraction of propionic acid in the side stream product was 93.8%, and the mass fraction of butyric acid in the bottom product was 96.2%. The thermosensitive ternary mixture was effectively separated without any material decomposition. This embodiment demonstrates that the partitioned column experimental apparatus can achieve reduced-pressure distillation via a vacuum interface, exhibiting good adaptability to thermosensitive materials. Furthermore, the apparatus has a wide adjustable parameter range; by adjusting parameters such as packing height, feed / discharge position, and operating pressure, it can meet experimental requirements under different operating conditions, expanding the application scenarios of the partitioned column experimental apparatus.

[0087] The above embodiments demonstrate that the partition column experimental apparatus provided by the present invention can achieve precise control of the number of trays, partition parameters, reflux ratio, gas-liquid phase distribution ratio, and feed / collection position, adapting to the separation requirements of mixtures with different compositions and operating conditions. It has stable separation performance and good data repeatability, providing a reliable experimental platform for the research of partition column distillation process.

Claims

1. A parameter-adjustable partitioned-wall distillation experimental apparatus, characterized in that, It includes a feeding system, tower body, condenser, reboiler, side stream extraction device, gas phase distribution device, liquid phase distribution device, and control system; The tower body includes a common rectification section, a pre-separation section, a main separation section, and a common stripping section arranged along the material separation direction. The pre-separation section and the main separation section are two independent and parallel tower sections. The upper ends of the pre-separation section and the main separation section are respectively connected to the common rectification section, and the lower ends are respectively connected to the common stripping section, so as to jointly form an equivalent partition wall tower structure without a solid partition. The pre-separation section is provided with a feed inlet connected to the feeding system, the main separation section is provided with a side-stream outlet connected to the side-stream outlet device, the condenser is connected to the common rectification section, and the reboiler is connected to the common stripping section. The common rectification section, the pre-separation section, the main separation section, and the common stripping section are all packed column sections. The packing height in at least some of the packed column sections can be independently adjusted to adjust the theoretical plate number, equivalent partition height, and equivalent partition position of the column body. The liquid phase distribution device is disposed between the common rectification section, the pre-separation section, and the main separation section, and is used to adjust the liquid phase distribution ratio flowing from the common rectification section to the pre-separation section and the main separation section; The gas phase distribution device is disposed between the common stripping section, the pre-separation section, and the main separation section, and is used to adjust the gas phase distribution ratio flowing from the common stripping section to the pre-separation section and the main separation section; The control system is connected to the side-line extraction device, the gas phase distribution device, and the liquid phase distribution device respectively, and is used to adjust the side-line extraction rate, the gas phase distribution ratio, and the liquid phase distribution ratio.

2. The partitioned-wall distillation experimental apparatus according to claim 1, characterized in that, The common rectification section, the pre-separation section, the main separation section, and the common stripping section are detachably connected by flanges or chucks. The packing in each of the packed tower sections can be disassembled, replaced, or added or removed to adjust the packing height and / or packing specifications of the corresponding packed tower section.

3. The partitioned-wall distillation experimental apparatus according to claim 1 or 2, characterized in that, The packing height of the pre-separation section and the main separation section is used to determine the equivalent partition wall height. The combination of packing heights of the common rectification section and the common stripping section is used to determine the position of the equivalent partition wall. The theoretical plate number of each packed column section is determined based on the corresponding packing height and the equivalent plate height of the packing used.

4. The partitioned-wall distillation experimental apparatus according to claim 1, characterized in that, The gas phase distribution device includes a gas phase channel that is connected to the pre-separation section and the main separation section respectively, a liquid phase channel for supplying liquid phase into the common stripping section, an overflow weir disposed in the liquid phase channel, an electric regulating valve disposed in at least one of the gas phase channels, and a differential pressure detector for detecting the gas phase flow state of the pre-separation section and the main separation section. The control system is configured to adjust the opening of the electric regulating valve according to the detection result of the differential pressure detector and the pre-established correspondence between the valve opening and the gas phase flow rate, so that the gas phase distribution ratio reaches the set value.

5. The partitioned-wall distillation experimental apparatus according to claim 1, characterized in that, The liquid phase distribution device includes a first liquid accumulation plate, a first flow channel and a second flow channel respectively connecting the pre-separation section and the main separation section, and an electromagnetically driven flow switching component; The flow guiding switching component can switch between a first working state and a second working state, so that the liquid phase in the first liquid accumulation pan flows into the pre-separation section and the main separation section through the first flow guiding channel and the second flow guiding channel, respectively. The control system adjusts the liquid phase distribution ratio by adjusting the ratio of the duration of the first working state to that of the second working state.

6. The partitioned-wall distillation experimental apparatus according to claim 1, characterized in that, The side-line extraction device includes a second liquid collection plate, a downcomer, a float valve through which the gas supply phase passes, an extraction guide that can switch between extraction and non-extraction positions, a side-line extraction outlet corresponding to the extraction guide, and an electromagnetic drive for driving the extraction guide. The control system adjusts the ratio of the energization time to the de-energization time of the electromagnetic drive component, thereby adjusting the time ratio during which the extraction guide component is in the extraction position, and thus adjusting the side-line extraction rate.

7. The partitioned-wall distillation experimental apparatus according to claim 1, characterized in that, The pre-separation section is provided with multiple switchable feed inlets along the height direction, and the main separation section is provided with multiple switchable side feed outlets along the height direction. The feed position can be adjusted by switching the feed inlet at different heights, the side outlet position can be adjusted by switching the side outlet at different heights, and the feed position and / or the side outlet position can also be adjusted by adjusting the packing height on the upper and lower sides of the corresponding feed inlet or side outlet.

8. The partitioned-wall distillation experimental apparatus according to claim 1, characterized in that, It also includes a reflux ratio distributor, temperature sensor, pressure sensor, level sensor, and vacuum system; The reflux ratio distributor includes an oscillating guide that can switch between a reflux position and a tower top extraction position, and an electromagnetic coil for driving the oscillating guide. The control system adjusts the reflux ratio by adjusting the time ratio of the oscillating guide in the reflux position and the tower top extraction position. The temperature sensor and the pressure sensor are arranged along the height of the tower body, the liquid level sensor is arranged in the reboiler and / or the product storage tank, and the vacuum system is connected to at least one of the condenser, the top product storage tank, the side-stream product storage tank and the bottom product storage tank. The diameter of the tower body is less than 300 mm.

9. A method for adjusting experimental parameters in partitioned distillation, characterized in that, The experimental apparatus for partitioned distillation according to any one of claims 1 to 8 includes the following steps: Based on the material system to be separated and the target separation requirements, the required number of theoretical plates for the common rectification section, pre-separation section, main separation section and common stripping section are determined respectively. By adjusting the packing height of the corresponding packed column sections, the number of theoretical plates, equivalent partition wall height and equivalent partition wall position of the partition wall rectification experimental device are set. Select the feed position of the pre-separation section and the side-line extraction position of the main separation section according to the material system to be separated; The material to be separated is introduced into the pre-separation section, and the material in the bottom of the column is heated by the reboiler and the gas phase at the top of the column is condensed by the condenser. The gas phase distribution ratio entering the pre-separation section and the main separation section from the common stripping section is adjusted by the gas phase distribution device, the liquid phase distribution ratio entering the pre-separation section and the main separation section from the common rectification section is adjusted by the liquid phase distribution device, and the side stream extraction rate is adjusted by the side stream extraction device. After reaching a stable distillation state, light component products, intermediate component products, and heavy component products are collected from the top, side stream, and bottom of the column, respectively.

10. The method for adjusting experimental parameters in partitioned distillation according to claim 9, characterized in that, The adjustment of the gas phase distribution ratio includes: detecting the pressure difference or gas phase flow parameters between the pre-separation section and the main separation section, determining the actual gas phase distribution ratio based on the detection results, and adjusting the opening of the electric regulating valve based on the deviation between the actual gas phase distribution ratio and the target gas phase distribution ratio. The adjustment of the liquid phase distribution ratio includes: adjusting the ratio of the duration of the liquid phase distribution device under different flow conditions, so that the liquid phase flows into the pre-separation section and the main separation section respectively according to the target liquid phase distribution ratio; The side-line extraction rate and return ratio are adjusted by adjusting the ratio of the energizing time to the de-energizing time of the corresponding electromagnetic drive component.

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