Supergravity rotating bed device based on end effect region

Abstract

A supergravity rotating bed device based on an end effect zone comprises a shell and a rotating disc located in the shell and rotationally connected with the shell, the rotating disc is provided with dynamic filler which extends upwards and is not connected with the top face of the shell, the top in the shell is provided with static filler which extends downwards and is not connected with the rotating disc, and the dynamic filler and the static filler are nested with each other. Flow guide rings are arranged on the top surface of the rotating disc and the top surface in the shell, the flow guide rings located on the rotating disc are used for preventing a liquid phase and a gas phase from being short-circuited in a gap between the static filler and the rotating disc, and the flow guide rings located on the top surface in the shell are used for preventing the liquid phase and the gas phase from being short-circuited in a gap between the static filler and the top surface in the shell; a plurality of end effect regions are created by adopting a mode of combining the dynamic filler and the static filler, so that the utilization efficiency and the mass transfer efficiency of the filler regions are improved, and the distribution uniformity of a liquid phase and a gas phase is improved by arranging the spoilers between the dynamic filler and the static filler, so that the overall mass transfer performance of the supergravity rotating bed is improved.

Description

Technical Field

[0001] The present invention relates to the field of mass transfer in petrochemical industry, and more particularly to a high gravity rotating bed device based on an end effect zone. Background Art

[0002] A high gravity rotating bed is a new type of device that uses a centrifugal force field to replace the gravity field to strengthen the molecular diffusion between molecules and the interfacial contact between phases, thereby enhancing the mass transfer process. The high gravity rotating bed has the advantages of small equipment volume, low energy consumption, convenient startup and shutdown, and small liquid holdup. It is widely used in the fields of distillation, absorption, separation, chemical precipitation, and oxidation. Compared with traditional gas-liquid mass transfer equipment such as packed towers and plate towers, the high gravity rotating bed has a special phenomenon, that is, the high gravity rotating bed has an end effect zone. The so-called end effect zone refers to a small area at the inner edge of the rotor packing (i.e., the radial thickness of the packing is about 10-30 mm), where the mass transfer accounts for a large proportion of the total mass transfer of all packings. The mass transfer contribution in the end effect zone is several times that of other regions of the rotor packing, and it is the core area of the overall mass transfer.

[0003] The reason why the end effect zone can strengthen mass transfer is that before the liquid enters the end effect zone, the circumferential velocity is zero and the radial velocity is the largest. When the liquid collides with the packing with a large circumferential velocity at the edge of the inner edge of the packing, the relative velocity between the liquid and the packing is the largest at this time, and the collision and shear of the packing on the liquid are the most intense. The liquid is dispersed into tiny droplets, and the specific surface area of the liquid increases sharply, providing a sufficient interface for gas-liquid mass transfer and reaction. After the liquid flows through the end effect zone, the liquid (droplets, liquid films or liquid filaments) obtains a circumferential velocity similar to that of the packing, resulting in a decrease in the relative velocity between the liquid and the packing, weakening of the collision and cutting, and the liquid can quickly move with the packing in a relatively stable liquid film form and be thrown out of the packing under the action of centrifugal force.

[0004] Chinese Patent CN 102258880 B discloses a high gravity rotating bed device for strengthening the end effect zone of the rotor by segmented liquid inlet. By arranging multiple layers of annular packing layers in the cavity and arranging liquid inlet spray pipes between adjacent annular packing layers for segmented liquid distribution, multiple end effect zones are formed, and the flow flux of the packing is kept substantially unchanged to achieve the purpose of efficient mass transfer. However, the spray pipes involved in this invention will occupy a large amount of space between the packing layers, thereby reducing the packing space. Moreover, due to segmented liquid inlet and liquid replenishment, the mixing of the untransferred liquid near the outside and the fully mass-transferred liquid inside will reduce the mass transfer driving force, thereby affecting the mass transfer effect.

[0005] The liquid phase distribution uniformity in the high gravity rotating bed has a great influence on the mass transfer effect. For example, Chinese Patent CN114832419 A discloses a concentric circle type high gravity rotating bed and a continuous rectification system. By installing a louver type liquid redistributor in the high gravity rotating bed, the unevenness of liquid distribution in the bed is reduced. Although this louver type liquid redistributor can play a role in liquid redistribution, it will also cause a great reduction in the gas phase channel, a sharp increase in the gas phase pressure drop, and at the same time, it will also cause liquid phase entrainment and backmixing, which will ultimately affect the mass transfer effect. Summary of the Invention

[0006] The present invention aims to provide a high gravity rotating bed device based on the end effect region to improve the overall mass transfer performance of the high gravity rotating bed.

[0007] To solve the above technical problems, the specific solution adopted by the present invention is as follows: A high gravity rotating bed device based on the end effect region, including a housing and a rotating disk rotatably connected inside the housing. The rotating disk is provided with moving packing extending upward and not connected to the top surface of the housing. The top of the housing is provided with static packing extending downward and not connected to the rotating disk. The moving packing and the static packing are nested with each other. The top surface of the rotating disk and the top surface inside the housing are both provided with flow guiding rings. The flow guiding ring located on the rotating disk is used to prevent the liquid phase and the gas phase from short-circuiting through the gap between the static packing and the rotating disk. The flow guiding ring located on the top surface inside the housing is used to prevent the liquid phase and the gas phase from short-circuiting through the gap between the moving packing and the top surface inside the housing. The top surface inside the housing is provided with a first flow disturbing plate and a second flow disturbing plate extending downward. The first flow disturbing plate is distributed inside the static packing, and the second flow disturbing plate is distributed outside the static packing. The housing is respectively provided with a liquid phase outlet and a gas phase outlet. The top of the housing is provided with a gas phase pipe, and the side of the gas phase pipe is provided with a liquid phase pipe extending into the housing. The liquid phase pipe is distributed with a liquid distributor.

[0008] The bottom of the housing is provided with a motor for driving the rotation of the rotating disk. The output shaft of the motor extends into the housing, and the bottom of the rotating disk is provided with a driving shaft for connecting with the output shaft of the motor.

[0009] The side of the flow guiding ring located on the rotating disk facing the liquid phase pipe is an inclined surface. The included angle between the inclined surface of the flow guiding ring and the rotating disk is 15° - 45°, and the top of the flow guiding ring is higher than the bottom end face of the static packing.

[0010] The side of the flow guiding ring located on the top surface inside the housing facing the liquid phase pipe is an inclined surface. The included angle between the inclined surface of the flow guiding ring and the top surface of the housing is 15° - 45°, and the bottom of the flow guiding ring is lower than the top end face of the moving packing.

[0011] The first flow disturbing plate is inclined along the radial direction of the moving packing and distributed circumferentially along the central axis of the moving packing.

[0012] The second spoiler is radially parallel to the moving packing and circumferentially distributed along the central axis of the moving packing.

[0013] The first spoiler and the second spoiler have the same structure, and spoiler fins for separating fluids are provided on the first spoiler and the second spoiler. The spoiler fins are arranged with convex structures in the shape of "<" or "—", and the height of the convex structures is 1 to 10 mm.

[0014] A gas distributor extending downward and not connected to the bottom of the outer shell is provided on the top surface inside the outer shell. The gas distributor is sleeved outside the moving packing, and the gas distributor is a cylindrical hollow structure with an opening area provided thereon.

[0015] The opening size of the opening area gradually increases from top to bottom.

[0016] The opening area is lower than the gas phase outlet.

[0017] Due to the adoption of the above technical solutions, the present invention has the following beneficial effects:

[0018] By adopting the combination of moving packing and static packing to create multiple end effect regions, the utilization efficiency and mass transfer efficiency of the packing region are improved. By arranging spoilers between the moving packing and the static packing, the distribution uniformity of the liquid phase and the gas phase is improved, thereby improving the overall mass transfer performance of the high-gravity rotating bed. Description of the Drawings

[0019] Figure 1 is a schematic structural diagram of the present invention;

[0020] Figure 2 is Figure 1 an enlarged schematic diagram of the structure at A;

[0021] Figure 3 is a schematic diagram of the distribution of the first spoiler and the second spoiler of the present invention;

[0022] Figure 4 is a schematic diagram of the structure of the spoiler fin of the invention;

[0023] Figure 5 is a schematic diagram of the opening area of the gas distributor of the present invention;

[0024] 1. Liquid phase outlet; 2. Liquid distributor; 3. Drive shaft; 4. Guide ring; 5. Turntable; 6. Moving packing; 7. Gas distributor; 8. Gas phase outlet; 9. Outer shell; 10. First spoiler; 11. Gas phase pipe; 12. Liquid phase pipe; 13. Static packing; 14. Second spoiler; 15. Spoiler fin. Detailed Embodiments

[0025] Such as Figure 1 AndFigure 3 As shown, a supergravity rotating bed device based on an end effect region includes a housing 9 and a rotating disk 5 rotatably connected inside the housing 9. A drive shaft 3 is provided at the bottom of the rotating disk 5, and the drive shaft 3 extends to the bottom of the housing 9. A motor is provided at the bottom of the housing 9, and the output shaft of the motor is connected to the drive shaft 3 to drive the rotating disk 5 to rotate through the drive shaft 3. An active packing 6 extending upward and not contacting the top surface of the housing 9 is provided on the rotating disk 5. The specific structure of the active packing 6 is as Figure 3 shown. The active packing 6 is divided into an inner layer and an outer layer. A static packing 13 extending downward and not contacting the rotating disk 5 is provided at the top inside the housing 9. The active packing 6 and the static packing 13 are nested with each other, as Figure 3 shown, the static packing 13 is located in the middle of the inner and outer layers of the active packing 6.

[0026] The radial thicknesses of both the active packing 6 and the static packing 13 are 15 mm. Both the active packing 6 and the static packing 13 are wire mesh packings, and the porosity of the packing is 94%.

[0027] Flow guiding rings 4 are provided on both the top surface of the rotating disk 5 and the top surface inside the housing 9. Two flow guiding rings 4 are provided on the top surface inside the housing 9. The two flow guiding rings 4 have the same structure and are both used to prevent the liquid phase and the gas phase from short - circuiting through the gap between the active packing 6 and the top surface inside the housing 9. The side of the flow guiding ring 4 on the top surface inside the housing 9 facing the liquid phase pipe 12 is an inclined surface, and the angle between the inclined surface of the flow guiding ring 4 and the top surface of the housing 9 is 15° - 45°. The bottom of the flow guiding ring 4 is lower than the top end face of the active packing 6. One flow guiding ring 4 is provided on the rotating disk 5 to prevent the liquid phase and the gas phase from short - circuiting through the gap between the static packing 13 and the rotating disk 5. The side of the flow guiding ring 4 on the rotating disk 5 facing the liquid phase pipe 12 is an inclined surface, and the angle between the inclined surface of the flow guiding ring 4 and the rotating disk 5 is 15° - 45°. The top of the flow guiding ring 4 is higher than the bottom end face of the static packing 13. In this way, the liquid phase and the gas phase can smoothly pass through the static packing 13 and the active packing 6 without short - circuiting through the gap.

[0028] As Figure 3As shown in the figure, on the top surface of the outer shell 9, there are a first spoiler 10 and a second spoiler 14 extending downward. Neither the first spoiler 10 nor the second spoiler 14 is in contact with the turntable 5. The first spoiler 10 is distributed inside the static packing 13, and the second spoiler 14 is distributed outside the static packing 13. The spoiler located inside the static packing 13 is inclined along the radial direction of the moving packing 6 or the static packing 13 and is distributed circumferentially along the central axis of the moving packing 6. The spoiler located outside the static packing 13 is parallel to the radial axis of the moving packing 6 or the static packing 13 and is distributed along the central axis of the moving packing 6. When the gas phase carries liquid droplets and flows out from the innermost moving packing 6, the liquid droplets have a large radial velocity and a certain circumferential velocity. In order to generate a greater velocity difference between the fluid and the static packing 13, the spoiler located inside the static packing 13 is made to have a certain slope, so as to partially convert the radial velocity energy of the fluid into circumferential velocity and form an end effect area. When the fluid flows out of the static packing 13 area, its circumferential velocity is relatively low. After being guided by the spoiler 14, the circumferential velocity is converted into radial velocity, and there is a large velocity difference with the moving packing 6. The spoiler located outside the static packing 13 plays a role in evenly distributing the fluid in the axial direction.

[0029] The first spoiler 10 and the second spoiler 14 have the same structure and are both provided with spoiler vanes for separating the fluid. On the spoiler vanes, there are raised structures arranged in the shape of "<" or "—". The height of the raised structures is 1 - 10 mm. Due to the high flow velocity and large inertia of the fluid, and in addition, there is a pressure difference inside and outside the rotating bed, the fluid can quickly flow through the spoiler under the action of inertia and pressure difference. The raised structures in the shape of "<" or "—" on the spoiler vanes can divide the fluid, making its distribution more uniform in the axial direction.

[0030] As Figure 1 shown in the figure, on the outer shell 9, there are a liquid phase outlet 1 and a gas phase outlet 8 respectively. The gas phase outlet 8 is located at the bottom of the outer shell 9, and the gas phase outlet 8 is located on the side of the outer shell 9 and close to the top of the outer shell 9. On the top surface inside the outer shell 9, there is a gas distributor 7 extending downward and not in contact with the bottom of the outer shell 9. The gas distributor 7 is sleeved outside the moving packing 6, and the gas distributor 7 is a cylindrical hollow structure. As Figure 5 shown in the figure, the gas distributor 7 is provided with an opening area, and the holes opened in the opening area penetrate through the gas distributor 7. When there is no gas distributor 7, the gas phase will flow in the upper part of the rotating bed packing area and flow out from the gas phase outlet 8 because the resistance is the smallest in this way. In order to make the axial distribution of the gas in the rotating bed packing area more uniform, it is necessary to add a gas distributor 7 near the gas phase outlet 8 to make the resistance of the gas flow more consistent in the axial direction.

[0031] The height of the perforated area of the gas distributor 7 should be lower than the position of the gas phase outlet 8. The perforated area can be provided with round holes, rectangular holes, diamond-shaped holes, etc., and the size of the holes can gradually increase from top to bottom. The purpose is to accelerate the flow rate of the gas phase in the lower part. The lowest end of the gas distributor 7 can reach the position of the turntable 5 but does not contact the turntable 5. At this time, due to the influence of the flow inertia and the holes of the gas distributor 7, the resistance of the gas flowing through the holes is less than that of flowing through the bottom gap of the gas distributor 7, so the resistance of the gas flowing through can be made more consistent.

[0032] As Figure 1 shown, a gas phase pipe 11 is provided at the top of the outer shell 9, and a liquid phase pipe 12 extending into the outer shell 9 is provided on the side of the gas phase pipe 11. A liquid distributor 2 is distributed on the liquid phase pipe 12, and the liquid distributor 2 can uniformly spray the liquid phase on the moving packing 6.

[0033] The specific usage method of the present invention is briefly described as follows:

[0034] The motor drives the drive shaft 3 to rotate, and the drive shaft 3 drives the turntable 5 and the moving packing 6 fixed on the turntable 5 to rotate at a high speed together. The liquid enters the high-gravity rotating bed from the liquid phase pipe 12, and after being sprayed by the liquid distributor 2, it is uniformly distributed on the moving packing 6. At this time, the circumferential velocity of the liquid is zero and the radial velocity is the largest. The liquid collides with the moving packing 6 with a large circumferential velocity at the inner edge of the moving packing 6. The relative velocity between the liquid and the moving packing 6 is the largest, and the collision and shear of the moving packing 6 on the liquid are the most intense. At this time, the liquid is dispersed into tiny droplets, and the specific surface area increases sharply, forming an end effect area in the area of the moving packing 6; then the liquid flows through and detaches from the moving packing 6. At this time, the liquid has a circumferential velocity similar to that of the moving packing 6 and impacts the static packing 13 at a high circumferential velocity and a certain radial velocity under the action of the spoiler. Since the static packing 13 is stationary, there is a large relative velocity between the liquid and the static packing 13, and the collision and shear of the static packing 13 on the liquid are intense, and the specific surface area of the liquid increases again, forming an end effect area again in the area of the static packing 13. After the liquid detaches from the static packing 13, it flows through the spoiler again, and after being guided and evenly distributed by the spoiler, it flows radially to the next layer of moving packing 6 and impacts the next layer of moving packing 6 again, forming an end effect area again until it flows out from the liquid phase outlet 1.

[0035] Since the liquid will gradually reduce its speed under the action of the static packing 13 when flowing through the static packing 13, resulting in the liquid being unable to flow out of the static packing 13, the present invention adopts a co-current flow mode of gas-liquid two-phase, and uses the high-speed flow of the gas phase to drive the liquid phase to flow out of the static packing 13, so that the gas phase flow path and the liquid phase flow path can be the same.

[0036] Example:

[0037] In this embodiment, a NaOH solution is used to absorb CO2 gas. The dynamic packing 6 of the high-gravity rotating bed of the present invention has a radial thickness of 15 mm, and the static packing 13 has a radial thickness of 15 mm. Both are made of wire mesh packing, with a packing porosity of 94%. The angle between the inclined plane of the flow guide ring 4 and the turntable 5 is 30°. The concentration of the absorbent NaOH solution is 0.05 mol / L. A steel cylinder provides CO2 and N2, and the two are premixed to a CO2 content of 2% (volume ratio) and then introduced into the high-gravity rotating bed. The gas flow rate is 12 m 3 / h, and the liquid flow rate is 300 L / h. The absorption effect is shown in Table 1.

[0038]

Claims

1. A supergravity rotating bed device based on an end effect region, characterized in that: It includes a housing (9) and a rotating disc (5) rotatably connected inside the housing (9). A moving packing (6) that extends upward and does not contact the top surface of the housing (9) is provided on the rotating disc (5). A static packing (13) that extends downward and does not contact the rotating disc (5) is provided at the top inside the housing (9). The moving packing (6) and the static packing (13) are nested with each other. Flow guiding rings (4) are provided on the top surface of the rotating disc (5) and the top surface inside the housing (9). The flow guiding ring (4) located on the rotating disc (5) is used to prevent the liquid phase and the gas phase from short-circuiting through the gap between the static packing (13) and the rotating disc (5). The flow guiding ring (4) located on the top surface inside the housing (9) is used to prevent the liquid phase and the gas phase from short-circuiting through the gap between the moving packing (6) and the top surface inside the housing (9). A first spoiler (10) and a second spoiler (14) that extend downward are provided on the top surface of the housing (9). The first spoiler (10) is distributed inside the static packing (13), and the second spoiler (14) is distributed outside the static packing (13). A liquid phase outlet (1) and a gas phase outlet (8) are respectively provided on the housing (9). A gas pipe (11) is provided at the top of the housing (9). A liquid pipe (12) that extends into the housing (9) is provided on the side of the gas pipe (11). A liquid distributor (2) is distributed on the liquid pipe (12).

2. The supergravity rotating bed device based on the end effect region according to claim 1, wherein: A motor for driving the rotating disc (5) to rotate is provided at the bottom of the housing (9). The output shaft of the motor extends into the housing (9). A driving shaft (3) for connecting with the output shaft of the motor is provided at the bottom of the rotating disc (5).

3. The hypergravity rotating bed device based on the end effect area according to claim 1, characterized in that: The side of the flow guiding ring (4) located on the rotating disc (5) facing the liquid pipe (12) is an inclined surface. The included angle between the inclined surface of the flow guiding ring (4) and the rotating disc (5) is 15° - 45°. The top of the flow guiding ring (4) is higher than the bottom end face of the static packing (13).

4. The supergravity rotating bed device based on the end effect area according to claim 1, characterized in that: The side of the flow guiding ring (4) located on the top surface inside the housing (9) facing the liquid pipe (12) is an inclined surface. The included angle between the inclined surface of the flow guiding ring (4) and the top surface of the housing (9) is 15° - 45°. The bottom of the flow guiding ring (4) is lower than the top end face of the moving packing (6).

5. The supergravity rotating bed device based on the end effect region according to claim 1, characterized in that: The first spoiler (10) is inclined along the radial direction of the moving packing (6) and is distributed circumferentially along the central axis of the moving packing (6).

6. The hypergravity rotating bed device based on the end effect region according to claim 1, characterized in that: The second spoiler (14) is parallel to the radial direction of the moving packing (6) and is distributed circumferentially along the central axis of the moving packing (6).

7. The supergravity rotating bed device based on the end effect area according to claim 1, wherein: The first spoiler (10) and the second spoiler (14) have the same structure, and spoiler pieces (15) for separating the fluid are provided on the first spoiler (10) and the second spoiler (14). Raised structures in the form of "<" or "—" are arranged on the spoiler pieces (15). The height of the raised structures is 1 - 10 mm.

8. The supergravity rotating bed device based on the end effect region according to claim 1, characterized in that: A gas distributor (7) that extends downward and does not contact the bottom of the housing (9) is provided on the top surface inside the housing (9). The gas distributor (7) is sleeved outside the moving packing (6). The gas distributor (7) is a cylindrical hollow structure, and an opening area is provided on the gas distributor (7).

9. The supergravity rotating bed device based on the end effect region according to claim 8, characterized in that: The opening size of the opening area gradually increases from top to bottom.

10. The supergravity rotating bed device based on the end effect area according to claim 9, characterized in that: The opening area is lower than the gas phase outlet (8).

Images