Online agent exchange unit and reactive distillation column using the same
By collecting and replenishing catalysts and packing materials in the reactive distillation column through an online catalyst replacement unit, the problem of downtime required for catalyst and packing material replacement is solved, mass transfer reaction efficiency is improved, and the operation process is simplified.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA PETROLEUM & CHEMICAL CORP
- Filing Date
- 2022-08-19
- Publication Date
- 2026-06-02
Smart Images
Figure CN117618958B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of oil refining and chemical technology, and in particular to an online exchange unit and a reactive distillation column using the unit. Background Technology
[0002] Reactive distillation columns play a crucial role in petroleum refining and chemical production. During the reactive distillation process, multiple feed streams mix, transfer mass, and react. To accelerate mass transfer and increase the reaction rate, industrial processes often employ external packing materials and catalysts.
[0003] Catalysts and packings react with fluids through contact mass transfer, with the reaction or mass transfer occurring on the surface of the catalyst or packing. Therefore, to achieve maximum mass transfer efficiency and maximize the utilization of the catalyst and packing, the surface area of the catalyst and packing must be maximized during the manufacturing process. Currently, most existing catalysts and packings are granular, with smaller particles having a larger specific surface area. Granular catalysts and packings are stacked in a specific manner on the trays of a reactive distillation column. The rising gas flow and descending liquid flow over the particle surface accelerate the reaction and mass transfer, while the catalyst and packing particles also move within the trays with the fluid.
[0004] Catalysts and packing materials, especially fresh ones, can be very effective in reactive distillation columns, with the mass transfer rate increasing significantly in the initial stages after their addition. However, as the reaction continues, trace impurities, non-reactive substances, and toxic materials in the fluid gradually accumulate on the surface of the catalyst and packing materials, reducing their reactivity and consequently decreasing the mass transfer rate. When the activity of the catalyst and packing materials decreases excessively and its impact on product quality becomes significant, it is necessary to replace them by removing the deactivated catalyst and packing materials from the column and adding fresh ones.
[0005] Currently, the main method for changing the packing material in industry is to shut down the entire reactive distillation column and then manually unload the packing. The main problems with this method are that the start-up and shutdown times are long, the operation is complicated, the cost is high, and it greatly affects production efficiency.
[0006] Therefore, there is an urgent need for an online catalyst replacement unit that can replace the catalyst and packing in the column without interrupting production, and a reactive distillation column that uses this unit, so as to avoid affecting the gas-liquid mass transfer efficiency and reaction rate in the column, and without affecting production.
[0007] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention
[0008] The purpose of this invention is to provide an online catalyst replacement unit and a reactive distillation column using the unit, which is suitable for gas-liquid-solid reactions. It can recover exhausted catalyst and / or packing particles online and replenish an equal amount of fresh catalyst and / or packing particles online without the need for shutdown for catalyst replacement.
[0009] To achieve the above objectives, according to a first aspect of the present invention, an online catalyst exchange unit is provided for collecting deactivated solid catalyst and / or packing particles suspended in the liquid phase in a reactive distillation column, comprising: a receiving tray disposed on the inner wall of the reactive distillation column and above the liquid surface; a rotating mechanism disposed on one side of the inner wall of the column and corresponding to the position of the receiving tray; the rotating mechanism is controlled to rotate by a drive unit outside the column, and a plurality of fixed pins are evenly spaced on the outer circumference of the rotating mechanism; the highest point of the rotating mechanism is higher than the location of the receiving tray, and the lowest point is below the liquid surface and close to the column plate; and collection baskets, the number of which is equivalent to the number of pins, the collection baskets being hung on the pins; the collection baskets collecting the solid particles suspended in the liquid phase when rotating to below the liquid surface, and dumping the solid particles onto the receiving tray at the highest point.
[0010] Furthermore, in the above technical solution, the rotating mechanism may include: a turntable, which is vertically arranged with the highest point of the turntable being higher than the location of the receiving tray, and the lowest point of the turntable being below the liquid surface and close to the tower plate; and a main shaft, one end of which is fixed to the center of the turntable, and the other end of which passes through the tower wall and is connected to the drive unit.
[0011] Furthermore, in the above technical solution, a stop pin can be installed on the inner wall of the tower near the highest point of the turntable. When the collection basket moves to the stop pin, the side wall of the basket touches the stop pin, causing the basket to rotate around the pin to complete the overall flipping and dumping of the solid particles. The stop pin can be telescopic if needed.
[0012] Furthermore, in the above technical solution, the lowest point of the turntable can be set above the screen of the downcomer on the tray. When the collection basket moves to the corresponding area of the screen, the bottom of the basket can form a scraping effect on the screen.
[0013] Furthermore, in the above technical solution, the rotating mechanism can also be a cooperating mechanism of an annular guide rail and a slider, with the collection basket and the slider pivotally connected. During the process of the basket and the slider running together along the guide rail, the basket and the slider can rotate relative to each other.
[0014] Furthermore, in the above technical solution, the bottom of the receiving tray can be designed as a concave structure, and a discharge port is provided at the corresponding position of the concave structure and is smoothly connected to the bottom of the discharge port. An outward-opening valve is provided at the discharge port.
[0015] Furthermore, in the above technical solution, a feed inlet may be provided on the tower wall to replenish fresh catalyst and / or packing material in an amount equal to the collected solid particles.
[0016] Furthermore, in the above technical solution, the sieve aperture of the collection basket is smaller than the minimum particle size of the solid particles.
[0017] According to a second aspect of the present invention, a reactive distillation column suitable for gas-liquid-solid reactions is provided, comprising the aforementioned online exchange unit, which can be installed in each tray.
[0018] Furthermore, in the above technical solution, each tray of the reactive distillation column may also include a downcomer located on the side wall of the column body. The downcomer extends vertically and its bottom is below the liquid surface; the downcomers of adjacent trays are arranged on both sides.
[0019] Furthermore, in the above technical solution, a screen for intercepting solid particles is provided at the inlet of the downcomer, and the online exchange unit of each tray is located directly above the screen.
[0020] Furthermore, in the above technical solution, air holes can be opened on the tray to allow the rising gas phase to pass through, and the rising gas phase mixes with the liquid phase accumulated above the tray in a bubbling manner.
[0021] Furthermore, in the above technical solution, the basket of the online catalyst exchange unit can disturb the liquid phase during movement, which can be used to enhance gas-liquid mass transfer and accelerate catalytic reaction while collecting the failed catalyst and / or packing.
[0022] Compared with the prior art, the present invention has the following beneficial effects:
[0023] 1) This invention achieves uninterrupted online recovery of deactivated solid particles in a reactive distillation column through an online exchange unit;
[0024] 2) The online catalyst exchange unit of the present invention can also provide agitation in the tower while collecting deactivated particles, improve the gas-liquid-solid three-phase disturbance in the tower, increase the mass transfer reaction efficiency, and maximize the utilization rate of catalyst or packing.
[0025] 3) When the rotating mechanism of the present invention adopts a turntable or annular guide rail structure, since the turntable or annular guide rail is vertically set on one side of the tower wall, it does not occupy other space inside the tower; when the collection basket moves to the highest point, it is flipped by the action of the stop pin to continuously pour the failed particles onto the receiving tray. The structure is simple and has a low failure rate; when the collection basket moves to the lowest point, it can also form a scraping effect on the screen at the inlet of the downcomer of the lower tower plate, avoiding the accumulation of solid particles at the screen and causing flooding, effectively improving the flow capacity of the downcomer;
[0026] 4) The present invention can be used to collect failed particles through the retractable stop pin; the stop pin can also be retracted without the need to replace the reagent. At this time, the collection basket only becomes a stirring and disturbance component. During operation, three-phase disturbance of gas, liquid and solid can be realized, which effectively increases the mass transfer reaction efficiency.
[0027] 5) The online catalyst replacement unit of the present invention can collect deactivated particles and replenish an equal amount of fresh catalyst and / or filler as needed, thereby saving catalyst usage to the greatest extent possible.
[0028] 6) The present invention has a simple structure, is easy to control and operate, and is easy to adjust.
[0029] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it according to the contents of the specification, and to make the above and other objects, technical features and advantages of the present invention easier to understand, one or more preferred embodiments are listed below and described in detail with reference to the accompanying drawings. Attached Figure Description
[0030] Figure 1 This is a schematic diagram of the external structure of the reactive distillation column of the present invention.
[0031] Figure 2 This is a front view schematic diagram of the first embodiment of the online refrigerant exchange unit in the internal structure of the reactive distillation column of the present invention.
[0032] Figure 3 This is a side view schematic diagram of the first embodiment of the online exchange unit in the internal structure of the reactive distillation column of the present invention.
[0033] Figure 4 This is a side view schematic diagram of the second embodiment of the online exchange unit in the internal structure of the reactive distillation column of the present invention.
[0034] Explanation of key figure labels:
[0035] 1-Reactive distillation column, 10-Trade plate, 11-Discharge port, 12-New agent inlet, 13-Receiving tray, 14-Rotating disc, 141-Main shaft, 142-Pin, 15-Collection basket, 16-Downcomer, 161-Downcomer screen, 17-Stop pin, 18-Annular guide rail; A-Solid particles. Detailed Implementation
[0036] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.
[0037] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.
[0038] In this document, for ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” “above,” “upper,” etc., are used to describe the relationship of one element or feature to another element or feature in the accompanying drawings. It should be understood that spatial relative terms are intended to encompass different orientations of an object in use or operation, in addition to those depicted in the figures. For example, if an object in the figure is flipped, an element described as “below” or “under” another element or feature would be oriented “above” that element or feature. Thus, the exemplary term “below” can encompass both the downward and upward orientations. An object may also have other orientations (rotated 90 degrees or other orientations), and the spatial relative terms used herein should be interpreted accordingly.
[0039] In this document, the terms "first," "second," etc., are used to distinguish two different elements or parts, and are not used to define specific positions or relative relationships. In other words, in some embodiments, the terms "first," "second," etc., can also be used interchangeably.
[0040] This invention provides a reactive distillation column 1 suitable for gas-liquid-solid mass transfer reactions. The liquid phase flows downwards through downcomers to each tray, while the gas phase enters from the bottom up through vents in the trays and is sprayed into the liquid phase. This disturbs the liquid phase and the solid packing and / or catalyst particles suspended in it, enhancing gas-liquid mass transfer and accelerating the gas-liquid reaction. Each tray in the reactive distillation column 1 of this invention is equipped with an online exchanger unit. As mass transfer and reaction proceed, the catalyst or packing will deactivate. To collect and remove the deactivated catalyst or packing particles from the column and add fresh catalyst or packing, this invention achieves uninterrupted online recovery of deactivated solid particles within the reactive distillation column through the online exchanger unit. Furthermore, when the recovery of deactivated particles is not required, the online exchanger unit of this invention can also provide agitation within the column, increasing the three-phase disturbance of the gas, liquid, and solid phases, improving mass transfer efficiency, and maximizing catalyst or packing utilization.
[0041] like Figure 1 As shown, in addition to the conventional gas-liquid phase inlet, gas-liquid phase outlet, and tray 10, each tray of the reactive distillation column 1 of the present invention is also provided with a deactivated particle discharge port 11 and a fresh catalyst inlet 12 for collecting deactivated solid particles and replenishing fresh solid catalyst and / or packing particles. An externally opening valve (not shown in the figure) may be provided on the outside of the discharge port 11 to control the discharge of the deactivated catalyst or packing particles collected in the tray.
[0042] Further as Figures 2 to 4As shown, the reactive distillation column 1 of the present invention is suitable for gas-liquid-solid reactions and is equipped with an online exchanger unit, which can be installed in each tray. Each tray 10 of the reactive distillation column 1 also includes a downcomer 16 disposed on the inner side wall of the column. The downcomer 16 extends vertically from the upper tray 10 and its bottom is below the liquid surface of the tray. The downcomers of adjacent trays are arranged on both sides, so that the liquid phase has a longer residence time on the tray. The inlet of the downcomer 16 of each tray is provided with a screen 161 for trapping solid particles. The tray 10 has gas holes (not shown in the figure) for the rising gas phase to pass through, and the rising gas phase can form a bubbling mixture with the liquid phase accumulated above the tray. At the same time, the solid catalyst / packing particles are suspended in the liquid phase and are continuously disturbed, forming a gas-liquid-solid three-phase disturbance, thereby carrying out the gas-liquid mass transfer reaction. In addition to the disturbance of the gas phase to the liquid phase, the collection basket 15 of the online exchange unit of the present invention can also cause disturbance to the liquid phase during its movement. While collecting deactivated solid particles A, it can also be used to enhance gas-liquid mass transfer and accelerate the catalytic reaction (the movement of the basket can also cause disturbance to the gas-liquid-solid phase when there are no deactivated particles to collect).
[0043] Further as Figure 2 , 3 As shown, the online catalyst exchange unit of the present invention is used for collecting depleted solid catalyst and / or packing particles suspended in the liquid phase in a reactive distillation column 1. It includes a receiving tray 13, a rotating mechanism, and collection baskets 15. The receiving tray 13 is located on the inner wall of the reactive distillation column 1 and is above the liquid surface. The rotating mechanism is located on one side of the inner wall of the column and corresponds to the position of the receiving tray (i.e., on the side where the receiving tray 13 is located). This rotating mechanism can be controlled to rotate by a drive unit outside the column (which may be a motor, not shown in the figure). Multiple fixed pins 142 are evenly spaced along the outer circumference of the rotating mechanism. The highest point of the rotating mechanism is higher than the location of the receiving tray 13, and the lowest point is below the liquid surface and close to the column plate 10. The number of collection baskets 15 is approximately equal to the number of pins 142, and the collection baskets 15 are hung on the pins 142 (the baskets can rotate around the pins). When the collection basket 15 rotates to below the liquid surface, it can collect the suspended solid particles A (i.e., deactivated catalyst and / or filler particles) in the liquid phase, and pour the solid particles onto the receiving tray 13 at the highest point.
[0044] Further as Figure 2 , 3 As shown, in the first embodiment, the rotating mechanism may include a turntable 14 and a main shaft 141. The turntable 14 is vertically arranged, with its highest point higher than the receiving tray 13, and its lowest point below the liquid surface and close to the tray 10. (Reference) Figure 3One end of the main shaft 141 is fixed to the center of the turntable 14, and the other end passes through the tower wall and is connected to a motor outside the tower. The main shaft 141 has a shaft seal with an opening in the tower body to prevent fluid leakage. The motor provides rotational power to the main shaft 141, thereby driving the turntable 14 to rotate. Further details are as follows... Figure 2 , 3 As shown, a stop pin 17 is provided on the inner wall of the tower near the highest point of the turntable 14. When a collection basket 15 moves to the stop pin 17, the side wall of the basket touches the stop pin, causing the basket to rotate around the pin 142. That is, while the basket "revolves" around the main shaft 141, it "rotates" around the pin 142 at the stop pin 17, thus completing the overall flipping and dumping of solid particles at the highest point of the turntable 14. When it is not necessary to collect deactivated particles, the basket can also move to stir the liquid phase. Therefore, the stop pin can be set to a retractable state. When it is necessary to collect deactivated particles, the stop pin 17 is extended; when it is only necessary to increase the disturbance effect, the stop pin 17 can be retracted. Further as... Figure 2 , 3 As shown, preferably but not limitingly, the lowest point of the turntable 14 can be located above the downcomer screen 161 of the tray. When the collection basket 15 moves to the corresponding area of the screen 161, the bottom of the basket can create a scraping effect on the screen 161. Since solid particles suspended in the liquid phase will accumulate at the screen 161 when the liquid phase falls to the lower tray through the downcomer 16, the solid particles accumulated at the screen will affect the flow of the liquid phase and cause flooding. Therefore, the scraping effect of the bottom of the basket on the screen 161 can effectively avoid this flooding phenomenon.
[0045] The rotating mechanism can also be designed as a guide rail type, chain type, or other methods, as long as the collection basket 15 can move up and down in a circular motion. In the second embodiment, such as Figure 4 As shown, the aforementioned turntable and main shaft mechanism can be replaced by a mating mechanism of annular guide rail 18 and slider (not shown in the figure). In this embodiment, the collection basket 15 can be pivotally connected to the slider (i.e., also using a pin 142 fixed on the slider). During the movement of the basket and slider together along the guide rail, the basket and slider can rotate relative to each other. In this embodiment, the drive unit outside the tower needs to drive the slider to run along the guide rail. Other structures are the same as in the first embodiment and will not be described again here.
[0046] Further as Figures 2 to 4 As shown, the collection basket 15 can be configured as a cylindrical structure with a handle, which is slidably connected to the pin 142. The surface of the cylinder is provided with a porous mesh, the mesh size of which depends on the minimum size of the catalyst and packing particles. The basket can rotate around the pin 142 as a center, and can also move with the direction of change. Figure 3 Turntable 14 (or Figure 4The slider in the annular guide rail 18 moves in a circular motion inside the tower. During operation, when passing through the liquid phase, the porous collection basket 15 can effectively collect the catalyst and / or packing solid particles A, while the liquid or gas can flow out through the mesh on the surface of the basket. The shape of the collection basket 15 is not fixed; it can be cylindrical, rectangular, or irregular, but it cannot be a soft bag or mesh. The basket discharges when it reaches its highest point and contacts the downcomer screen 161 when it descends to its lowest point, scraping the solid particles off the screen and keeping the downcomer 16 unobstructed. In addition, as long as it is not affected by external forces, the opening of the collection basket must always face upwards.
[0047] Further as Figures 2 to 4 As shown, the bottom of the receiving tray 13 has a concave structure, and the discharge port 11 is located at a corresponding position on this concave structure. To facilitate discharge, the concave structure is smoothly connected to the bottom of the discharge port, and an outward-opening valve is provided at the discharge port 11. After collecting a sufficient amount of deactivated solid particles, the valve can be opened to remove them. The fresh catalyst inlet 12 opened on the tower wall can be used to replenish an equal amount of fresh catalyst and / or packing material to the collected solid particles.
[0048] The online catalyst and / or packing particle recovery operation using the online replacement unit of the first embodiment described above is as follows:
[0049] 1) As the reactive distillation process proceeds in the reactive distillation column 1, the catalyst and packing gradually become deactivated. When a change in product quality is detected at the outlet and it is determined that the catalyst or packing is not active enough and needs to be replaced, the motor is started to provide power to drive the main shaft 141 to rotate. The main shaft 141 drives the turntable and the collection basket 15 pivotally connected to the turntable to rotate, extending the stop pin 17 and starting the non-stop packing replacement operation.
[0050] 2) The collection basket 15, which moves down with the turntable 14, enters the liquid phase layer and collects catalyst or filler solid particles while moving in the liquid phase layer. The basket continues to move and, after passing the lowest point, moves up and leaves the liquid phase layer. The upward basket collects catalyst or filler solid particles from the liquid phase, while the liquid and gas flow out from the mesh of the basket.
[0051] 3) When the collecting basket 15 moves up the turntable 14 to near its highest point, the side of the basket contacts the stop pin 17. The upper part of the basket continues to move with the turntable and gradually tilts and flips, causing the catalyst or filler particles to gradually pour out and fall into the receiving tray 13. This process is repeated, and the solid particles collected from the liquid phase are continuously poured into the receiving tray 13.
[0052] 4) When there are enough catalyst or packing particles in the receiving tray 13, the valve of the discharge port 11 is opened, and the catalyst or packing particles are discharged from the reactive distillation column 1; when most of the catalyst or packing particles in the column are discharged, the valve of the feed port 12 is opened, and an equal amount of fresh catalyst or packing particles enter the reactive distillation column 1 to complete the catalyst replacement.
[0053] It should be noted that as reactive distillation proceeds, the activity of the catalyst or packing material in the reactive distillation column decreases, but it still retains a certain level of mass transfer reaction activity. At this point, there is no need to replace the catalyst. The stop pin 17 can be retracted, and the motor can be started to run the collection basket 15. In this case, the collection basket only serves to stir, which can increase the three-phase disturbance of gas, liquid, and solid within the tray and increase the mass transfer reaction efficiency.
[0054] Additionally, as solid catalyst or packing particles move down to the lower tray with the liquid flow, these particles tend to accumulate on the surface of the downcomer screen 161, causing screen blockage and reducing the downcomer's flow capacity. In this case, the motor can be turned on, and the stop pin 17 can be retracted, with the collection basket 15 serving only a stirring function. When the basket moves near the lowest point in the liquid layer, it tilts slightly due to the influence of the downcomer screen 161. The turntable 14 continues to rotate, and the lowest point of the basket begins to move across the surface of the downcomer screen 161 after passing the contact point. During this movement, it acts like a scraper, moving the solid particles on the screen surface, thereby clearing the downcomer screen and improving its flow capacity.
[0055] The foregoing description of specific exemplary embodiments of the present invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. Any simple modifications, equivalent changes, and alterations made to the foregoing exemplary embodiments should fall within the scope of protection of the present invention.
Claims
1. A reactive distillation column characterized in that, Collection of degraded solid catalyst and / or packing particles suspended in the liquid phase, including: A receiving tray is disposed on the inner wall surface of the reactive distillation column and is located above the liquid level; A rotating mechanism is located on one side of the inner wall of the tower and corresponds to the position of the receiving tray. The rotating mechanism is controlled to rotate by a drive unit outside the tower. Multiple fixed pins are evenly spaced around the outer circumference of the rotating mechanism. The highest point of the rotating mechanism is higher than the position of the receiving tray, and the lowest point is below the liquid surface and close to the tower plate. The rotating mechanism includes: a turntable, which is vertically arranged with its highest point higher than the position of the receiving tray and its lowest point below the liquid surface and close to the tower plate; and a main shaft, one end of which is fixed to the center of the turntable, and the other end of which passes through the tower wall and is connected to the drive unit. The number of collection baskets is equal to the number of pins, and the collection baskets are hung on the pins; when the collection baskets rotate and run below the liquid surface, they collect the solid particles suspended in the liquid phase, and at the highest point, they pour the solid particles into the receiving tray.
2. The reactive distillation column of claim 1, wherein, A stop pin is provided on the inner wall of the tower near the highest point of the turntable. When the collection basket moves to the stop pin, the side wall of the basket touches the stop pin, causing the basket to rotate around the pin to complete the overall flipping and dumping of solid particles.
3. The reactive distillation column of claim 2, wherein, The stop pin is retractable.
4. The reactive distillation column of claim 1, wherein, The lowest point of the turntable is located above the screen of the downcomer on the tray. When the collection basket moves to the corresponding area of the screen, the bottom of the basket creates a scraping effect on the screen.
5. The reactive distillation column of claim 1, wherein, The bottom of the receiving tray is concave, and a discharge port is provided at the corresponding position of the concave structure and is smoothly connected to the bottom of the discharge port. An outward-opening valve is provided at the discharge port.
6. The reactive distillation column of claim 5, wherein, The tower wall is provided with a feed inlet for replenishing fresh catalyst and / or packing material in an amount equal to the collected solid particles.
7. The reactive distillation column of claim 1, wherein, The sieve aperture of the collection basket is smaller than the minimum particle size of the solid particles.
8. The reactive distillation column of claim 1, wherein, Each tray of the reactive distillation column also includes a downcomer located on the side wall of the column body. The downcomer extends vertically and its bottom is below the liquid surface. The downcomers of adjacent trays are arranged on both sides.
9. The reactive distillation column of claim 8, wherein, The inlet of the downcomer is equipped with a screen for trapping solid particles.
10. The reactive distillation column of claim 8, wherein, The tray has vents for the rising gas phase to pass through, and the rising gas phase mixes with the liquid phase accumulated above the tray in a bubbling manner.
11. The reactive distillation column of claim 1, wherein, The basket disturbs the liquid phase during movement, which can enhance gas-liquid mass transfer and accelerate catalytic reactions while collecting exhausted catalysts and / or packing materials.