Gas-liquid parallel flow type internal circulation reaction equipment

Abstract

A main body part of the gas-liquid parallel flow type internal circulation reaction equipment is of a flat rectangular structure and sequentially comprises a ceramic membrane assembly, a perforated plate gas inlet cavity, a perforated plate with a flange structure, a reactor feed port, a reactor main body part, a reactor discharge port and an overflow structure from bottom to top, the two built-in guide plates divide the loop reactor into an ascending area, a descending area, a bottom gap area and a gas-liquid separation area; a screen is mounted in the middle of the rising area guide plate; according to the reactor, a multi-channel ceramic membrane assembly is arranged in the center of an air inlet plate to generate small-size bubbles, and a porous plate structure is adopted to generate large-size bubbles; the porous plate air inlet holes are distributed on two sides of the ceramic membrane air inlet. According to the invention, millimeter-level bubbles and micron-level bubbles are simultaneously fed, the difference of turbulence degrees at different radial areas is reduced, and the mass transfer efficiency and the adaptive capacity under different working conditions are improved. The energy consumption is reduced, and the manufacturing and production cost is reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of loop reactors, and particularly relates to a gas-liquid co-current type inner loop flow reaction equipment. BACKGROUND

[0002] The loop reactor has the advantages of simple structure, uniform shear force field, directional and orderly fluid flow, low energy consumption, high energy efficiency, excellent mixing, mass transfer and heat transfer performance, and the like, and is widely used in the fields of absorption, synthesis, fermentation and emission reduction, and the like, and has important significance for industrial production and environmental protection. The gas-liquid co-current type loop reactor, as a special loop reactor, can generate a bubble group composed of micro-bubbles and millimeter-bubbles, form a large gas-liquid contact area and realize the intensification of the gas-liquid mixing process, and has good application prospect and research value.

[0003] The existing loop reactor technology mainly includes gas distributors, screens and static mixers and the like inner component devices. The gas distributor, as one of the most important inner components in the loop reactor, directly determines the size and distribution of the initial gas bubbles. It can be seen that the existing technology has problems such as single feed gas bubble size, complex inner components and the like. Small-size gas bubbles can provide a large gas holdup and phase interface area, which helps to improve the mass transfer efficiency; but since the small gas bubbles are mostly spherical or nearly spherical, the surface fluidity is poor, and the phase interface renewal rate is low, which is not conducive to the improvement of the liquid phase mass transfer coefficient. Large-size gas bubbles can improve the degree of turbulence in the liquid phase, and the large gas bubbles are easy to deform and break, which increases the phase interface renewal rate, and helps to improve the liquid phase mass transfer rate. The complex inner component design will lead to the increase of the equipment investment, and the increase of the process design difficulty. In addition, there are problems such as the coalescence of gas bubbles in the rising zone and the like in the existing equipment.

[0004] CN202211128638.4 proposes a gas-lift loop reactor, which increases the gas-liquid contact area and gas holdup by disturbing the particles in the draft tube, fully mixes the gas-liquid two-phase, improves the mass and heat transfer rates, and has uniform temperature distribution, which is beneficial to gas-liquid or gas-liquid solid three-phase reaction. However, the addition of particles may increase the wear inside the reactor, and when the processed material has strong corrosiveness or viscosity, the particles may be corroded or bonded together, affecting their disturbance effect and the normal operation of the reactor. CN202311316369.9 proposes a multi-phase rotary loop flow mixing reactor, which combines cyclone and loop flow technology, uses cyclone tank to strengthen gas-liquid mixing, and cyclone blade to cut gas bubbles, which is beneficial to heat transfer, mass transfer and momentum transfer, improves gas phase distribution uniformity and reaction conversion rate, and reduces coking. But its structure is relatively complex, involving the cooperative work of multiple components. CN202322647059.7 proposes a gas-liquid phase mixing loop reactor, which buffers the liquid phase in the reaction inner shell and flows out into the settling shell for sedimentation, which can effectively reduce the accumulation of impurities in the equipment and pipeline, but the internal structure such as the settling shell may occupy a certain reaction space, resulting in a relatively small effective reaction volume of the reactor, which may not be suitable for large-scale production reactions.

[0005] Therefore, in order to solve the many problems existing in the industrial application of the loop reactor at this stage, the present application proposes a gas-liquid parallel flow loop reactor with simple structure, strong adaptability and large handling capacity on the basis of the prior art. SUMMARY

[0006] The present application proposes a gas-liquid parallel flow internal loop reaction equipment, which solves the problems of complex structure of traditional loop reactors, single size of generated gas bubbles, and inability to flexibly control the size of gas bubbles through ceramic membrane or porous plate gas inlet structure and screen mesh in the rising zone. It can realize multi-scale gas bubble simultaneous gas inlet and gas bubble size control inside the loop reactor. The invention can further reduce production and design cost, greatly improve mass transfer efficiency, and has broad industrial application prospects.

[0007] To achieve the above purpose, the present application provides a gas-liquid parallel flow internal loop reaction equipment, which comprises a loop reactor, and the main part of the loop reactor is in a flat rectangular structure; two built-in guide plates divide the loop reactor into four areas: rising zone, falling zone, bottom gap zone and gas-liquid separation zone; a screen mesh is installed in the middle position of the two built-in guide plates in the rising zone; the top and bottom of the loop reactor are respectively provided with a discharge port and a feed port.

[0008] Preferably, the discharge port on the top of the loop reactor is provided with an overflow weir.

[0009] Preferably, two kinds of bubble generators are used to generate bubbles of different sizes, one multi-channel ceramic membrane is placed in the center of the gas inlet plate to generate small-sized bubbles; the other is a perforated plate structure to generate large-sized bubbles, the gas inlet holes are evenly distributed on both sides of the ceramic membrane module, and the perforated plate assembly is provided with a gas inlet chamber, the gas enters the gas inlet chamber from the perforated plate gas inlet, and then enters the loop reactor through the perforated plate structure.

[0010] Preferably, the main part of the loop reactor and the bubble generator are connected by flanges or by welding.

[0011] Preferably, the reaction process includes: the gas phase enters from the bottom of the reactor as the dispersed phase, and is discharged from the top of the reactor, the liquid phase enters from the bottom of the reactor, and is discharged from the overflow weir at the top of the reactor, after the gas-liquid co-current flows into the reactor from the bottom gap zone, it flows upward along the rising zone to the gas-liquid separation zone, at this time, part of the gas is separated in the gas-liquid separation zone and escapes into the air from the top of the reactor; the liquid is discharged through the overflow device at the top of the tower; another part of the gas is entrained into the descending zone by the liquid; the difference in the distribution of the gas phase in the rising zone and the descending zone leads to the formation of a density difference, thereby realizing the circulation flow of the liquid phase in the reactor.

[0012] Preferably, the reaction process includes: part of the gas feed is permeated into the channel through the annular gap on the side of the ceramic membrane module, and forms horizontal and vertical shear flow with the liquid phase entering the channel from the bottom of the ceramic membrane module, thereby achieving bubble breaking and generating small-sized bubbles; another part of the gas feed enters the gas chamber and generates large-sized bubbles at the perforated plate to enter the reactor; this achieves the operation mode of simultaneously feeding millimeter-sized bubbles and micron-sized bubbles, and further provides sufficient interfacial area through micron-sized oxygen bubbles and mass transfer momentum through millimeter-sized nitrogen bubbles, thereby improving the mass transfer efficiency.

[0013] Preferably, by adjusting the structural parameters of the equipment and the gas inlet mode, bubbles of different sizes are generated to improve the adaptability of the loop reactor to different working conditions.

[0014] Based on the above technical solutions, the present application has at least one of the following beneficial effects relative to the prior art:

[0015] 1. In the loop reactor, a ceramic membrane module and a perforated plate are simultaneously fed to strengthen the gas inlet, millimeter-sized bubbles and micron-sized bubbles are simultaneously fed, which can be used in the fields of gas-liquid two-phase reaction, gas absorption, microbial culture, volatile organic compound reduction treatment, etc.

[0016] 2. The screen set in the rising zone of the loop reactor can break bubbles and change the direction of bubble movement, thereby increasing the flow field disturbance degree of the area near the two sides of the guide plate in the rising zone and reducing the difference in turbulent degree at different radial regions.

[0017] 3. The mass transfer efficiency is improved by providing sufficient interfacial area by micron-sized oxygen bubbles and mass transfer momentum by millimeter-sized nitrogen bubbles.

[0018] 4. By adjusting the equipment structure parameters and gas inlet mode, bubbles of different sizes can be generated, improving the ability of the loop reactor to adapt to different working conditions. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0020] Fig. 1 is a perspective view of the loop reactor;

[0021] Fig. 2 is a perspective view of the bubble generator;

[0022] Fig. 3 is a hole distribution diagram of the reactor flange or gas generator flange.

[0023] In the figure: 1, reactor discharge port; 2, overflow weir; 3, gas-liquid separation zone; 4, rising zone; 5, main body part; 6, screen; 7, flow guide plate; 8, falling zone; 9, bottom gap zone; 10, reactor feed port; 11, reactor flange; 12, orifice plate structure; 13, ceramic membrane assembly discharge port; 14, gas inlet chamber; 15, ceramic membrane; 16, ceramic membrane assembly liquid feed port; 17, ceramic membrane assembly gas feed port; 18, perforated plate gas inlet; 19, gas generator flange. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the present application more clear, the embodiments of the present application will be further described in detail below with reference to the drawings.

[0025] The terms "first", "second", "third", "fourth", "fifth", "sixth", "seventh" and "eighth" and the like (if any) in the specification of the present application and the above drawings are used to distinguish similar objects, and do not necessarily have to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0026] The present application is further described in conjunction with the drawings:

[0027] As Figs. 1-3As shown, a gas-liquid co-current internal loop reactor device, from bottom to top in turn for ceramic membrane assembly, porous plate gas inlet chamber, porous plate with flange structure, reactor feed port, reactor main part, reactor discharge port. The reactor is provided with a guide plate, and the screen is located in the middle of the guide plate.

[0028] The main part 5 of the reactor is in a flat rectangular structure, and two guide plates are arranged inside to divide the loop reactor into four areas: the upward area 4, the downward area 8, the bottom gap area 9, and the gas-liquid separation area 3. The screen is installed at a distance of 350 mm from the bottom of the guide plate in the upward area of the reactor. An overflow device is provided at the top of the tower to avoid the oscillation at the liquid outlet position interfering with the flow state in the reactor.

[0029] The reactor uses two kinds of bubble generators to generate bubbles of different sizes. One is a multi-channel ceramic membrane assembly 15 placed in the center of the gas inlet plate to generate small-size bubbles; the other is a perforated plate structure 12 to generate large-size bubbles, and the gas inlet holes are evenly distributed on both sides of the ceramic membrane assembly. The porous plate assembly is provided with a gas inlet chamber 14, and the gas enters the reactor from the perforated plate gas inlet after entering the gas inlet chamber. The bubble generator is connected with the reactor through a flange structure (i.e. reactor flange 11 and gas generator flange 19).

[0030] The loop reactor uses a gas-liquid continuous co-current operation mode, and the gas phase enters from the bottom of the reactor and is discharged from the top of the reactor. The liquid phase enters from the bottom of the reactor and is discharged from the overflow weir at the top of the reactor. After the gas-liquid co-current flows into the reactor from the bottom gap area, it flows upward along the upward area to the gas-liquid separation area. At this time, part of the gas is separated in the gas-liquid separation area and escapes into the air from the top of the reactor; the liquid is discharged through the overflow device at the top of the tower. Another part of the gas is entrained into the downward area by the liquid; the difference in the distribution of the gas phase in the upward area and the downward area leads to the formation of a density difference, thereby realizing the circulation flow of the liquid phase in the reactor.

[0031] Taking the mass transfer process of oxygen in water as an example, oxygen penetrates from the annular gap on the side of the ceramic membrane assembly into the channel, at which time water enters the channel from the bottom of the ceramic membrane assembly, and forms a vertical and horizontal shear flow with the gas flow in the channel, realizing bubble breaking and generating small-size bubbles. The nitrogen gas pressure is controlled at 0.1 MPa, and after entering the gas chamber, large-size bubbles are generated at the porous plate and enter the reactor. Therefore, the device realizes the operation mode of simultaneously introducing millimeter-size bubbles and micron-size bubbles, and further provides sufficient interfacial area through micron-size oxygen bubbles and mass transfer momentum through millimeter-size nitrogen bubbles, thereby improving the mass transfer efficiency. In addition, different sizes of bubbles can be generated by adjusting the structure parameters and gas inlet mode of the device, thereby improving the adaptability of the loop reactor to different working conditions.

[0032] A specific scheme provided by the present application:

[0033] The gas-liquid co-current internal loop reactor has a flat rectangular reactor main body part 5, the length of the reactor is 210 mm, the width is 50 mm, and the height is 940 mm; two built-in flow guide plates 7 divide the loop reactor into an upward region 4, a downward region 8, a bottom gap region 9 and a gas-liquid separation region 3; the length of the two flow guide plates 7 is 700 mm, the thickness is 5 mm, the plate spacing is 100 mm, the height of the bottom gap region 9 is 60 mm, and the height of the gas-liquid separation region 4 is 180 mm. A screen 6 is installed at a position 350 mm away from the bottom of the flow guide plate 7 in the upward region 4, the screen is 100 mm long, 50 mm wide and 1 mm thick; a discharge port 1 and a feeding port 10 are arranged above and below the reactor; the discharge port above the reactor is provided with an overflow device 2; and the bottom of the reactor is provided with a flange structure 11.

[0034] The reactor adopts two kinds of bubble generators to generate bubbles with different sizes. One is a multi-channel ceramic membrane assembly 15 with a diameter of 30 mm, a channel aperture of 4 mm and a membrane aperture of 200 nm, which is arranged at the center position of the gas inlet plate to generate small-size bubbles; the other is a 4-hole plate structure 12 with a hole diameter of 1 mm, which generates large-size bubbles, and the gas inlets are evenly distributed on both sides of the ceramic membrane assembly, and the hole spacing on both sides is 10 mm, and the hole spacing in the middle is 40 mm. The multi-hole plate assembly is provided with a gas chamber 14, and the gas enters the gas inlet chamber from the multi-hole plate gas chamber, and then enters the reactor through the hole plate structure.

[0035] The bubble generator is connected with the reactor through a flange structure, the flange is 350 mm long, 110 mm wide, the opening diameter is 4 mm, the opening center spacing is 40 mm, and the opening center distance from the flange edge is 15 mm.

[0036] The operation method of the gas-liquid co-current internal loop reactor of the present application is as follows: liquid enters the ceramic membrane assembly from the inlet below the ceramic membrane, and then enters the internal loop reactor; gas can directly enter the internal loop reactor through the hole plate structure, or enter the assembly from the gas inlet on the side of the ceramic membrane assembly, and then enter the internal loop reactor after forming a two-phase flow with the liquid; in the internal loop reactor, the gas phase in the bottom gap region flows upward along the upward region, a part of the gas is separated in the gas-liquid separation region, and another part of the gas is entrained into the downward region by the liquid; the difference in the distribution of the gas phase in the upward region and the downward region leads to the formation of a density difference, thereby realizing the circulating flow of the liquid phase in the reactor.

[0037] The above examples are only preferred embodiments for fully illustrating the present application, and the protection scope of the present application is not limited thereto. Any equivalent replacement or transformation made by the person skilled in the art on the basis of the present application is within the protection scope of the present application. The protection scope of the present application is subject to the claims.

Claims

1. A gas-liquid co-flow internal circulation reaction device, comprising a circulation reactor, characterized in that, The main body (5) of the circulating reactor is a flat rectangular structure; two built-in guide plates (7) divide the circulating reactor into four areas: rising zone (4), falling zone (8), bottom gap zone (9) and gas-liquid separation zone (3); a screen (6) is installed in the middle of the two built-in guide plates (7) in the rising zone (4); the circulating reactor is provided with an outlet (1) and an inlet (10) at the top and bottom respectively.

2. The device as described in claim 1, characterized in that, An overflow weir (2) is provided at the discharge port (1) above the circulating reactor.

3. The device as described in claim 2, characterized in that, Two types of bubble generators are used to generate bubbles of different sizes. One type uses a multi-channel ceramic membrane (15) placed at the center of the air inlet plate to generate small-sized bubbles; the other type uses a perforated plate structure (12) to generate large-sized bubbles. The air inlets are evenly distributed on both sides of the ceramic membrane assembly. The perforated plate assembly is provided with an air inlet chamber (14). After the gas enters the air inlet chamber (14) from the perforated plate air inlet (18), it enters the circulating reactor through the perforated plate structure (12).

4. The device as described in claim 3, characterized in that, The main body (5) of the circulating reactor and the bubble generator are connected by flanges or by welding.

5. The device as described in claim 4, characterized in that, The reaction process includes: the gas phase, as the dispersed phase, enters from the bottom of the reactor and exits from the top; the liquid phase enters from the bottom of the reactor and exits from the overflow weir at the top; the gas and liquid flow into the reactor from the bottom gap zone and then flow upwards along the rising zone to the gas-liquid separation zone. At this point, part of the gas is separated in the gas-liquid separation zone and escapes into the air from the top of the reactor; the liquid is discharged through the overflow device at the top of the tower; another part of the gas is entrained by the liquid into the falling zone; the difference in the distribution of the gas phase in the rising and falling zones leads to the formation of a density difference, thereby realizing the circulation of the liquid phase in the reactor.

6. The device as described in claim 5, characterized in that, The reaction process includes: a portion of the gas feed permeates into the channel through the annular gap on the side of the ceramic membrane module, forming a horizontal and vertical shear flow with the liquid phase entering the channel from the bottom of the ceramic membrane module, thereby breaking up the bubbles and generating small-sized bubbles; another portion of the gas feed enters the gas chamber and generates large-sized bubbles at the porous plate before entering the reactor; this achieves the operation mode of simultaneous gas intake of millimeter-sized and micron-sized bubbles, thereby providing sufficient phase interface area through micron-sized oxygen bubbles and providing mass transfer momentum through millimeter-sized nitrogen bubbles, thus improving mass transfer efficiency.

7. The device as described in claim 6, characterized in that, By adjusting the equipment's structural parameters and air intake method, bubbles of different sizes can be generated, thereby improving the adaptability of the circulating reactor to different operating conditions.

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