A stepped guide screen hole tray

Abstract

A stepped guide sieve hole tray includes inlet weir plates, tray plates and outlet weir plates in a stepped distribution; the middle part of the inlet weir plate opposite to the side of the tray plate is connected with liquid receiving plates distributed in the horizontal direction; the tray plate includes a first flat plate, a second flat plate, an upper inclined plate and a lower inclined plate, the first flat plate is connected with the bottom of the inlet weir plate, the first flat plate is provided with first guide holes consistent with the liquid phase flow direction, the second flat plate is connected with the outlet weir plate, the second flat plate is provided with first sieve holes, the number of the upper inclined plate and the lower inclined plate is multiple, the multiple upper inclined plates and the lower inclined plates are staggered and connected between the first flat plate and the second flat plate, the lower inclined plate is provided with second sieve holes or second guide holes consistent with the liquid phase flow direction, and the upper inclined plate is provided with third guide holes consistent with the liquid phase flow direction. The present application can improve the liquid layer distribution, reduce the flow resistance of high viscosity fluid, and provide better gas-liquid contact conditions.

Description

Technical Field

[0001] This invention relates to the field of chemical equipment technology, specifically a stepped guide sieve tray. Background Technology

[0002] The liquid level gradient on a tray is the driving force for liquid flow across the tray. When the liquid level gradient is too large, the liquid level at the tray inlet is higher than that at the outlet, leading to uneven gas distribution and reduced tray efficiency. Polymer melts generally have high viscosity, resulting in greater resistance when flowing on trays. Traditional bubble cap trays and valve trays further increase the liquid flow resistance due to the numerous components on the tray, leading to an even larger liquid level gradient.

[0003] CN 218740362 U discloses a stepped stripping tray, which reduces the liquid level difference by using a segmented, stepped installation method, effectively reducing gas-liquid resistance. However, this method does not effectively utilize the driving effect of the gas phase on the liquid phase, and the tray structure has multiple intermediate baffles, which is not conducive to the flow of high-viscosity fluids. CN 203916126U discloses a gas-liquid uniform distribution type high-efficiency guided floating valve tray. By punching guide holes in the liquid inlet area and the arc-shaped area of ​​the tray, the high-speed gas flowing out of the guide holes pushes the liquid on the tray towards the downcomer, reducing the liquid level gradient at the inlet and outlet ends of the tray. However, a significant liquid level difference still exists, resulting in uneven gas distribution and low tray efficiency. Summary of the Invention

[0004] The present invention aims to provide a stepped guide sieve tray to improve liquid layer distribution, reduce the flow resistance of high viscosity fluids, and provide better gas-liquid contact conditions.

[0005] To solve the above technical problems, the specific solution adopted by the present invention is as follows: a stepped guide sieve tray, comprising an inlet weir plate, a tray plate, and an outlet weir plate arranged in a stepped manner from top to bottom; a liquid receiving tray distributed in a horizontal direction is connected to the middle of the side of the inlet weir plate opposite to the tray plate, and lateral holes are opened at intervals on the inlet weir plate below the liquid receiving tray; the tray plate includes a first plate, a second plate, an upper inclined plate, and a lower inclined plate, the first plate is connected to the bottom of the inlet weir plate, and a first guide hole is opened on the first plate in the same direction as the liquid flow, the second plate is connected to the outlet weir plate, and a first sieve hole is opened on the second plate, and the number of upper inclined plates and lower inclined plates is multiple, and the multiple upper inclined plates and lower inclined plates are staggered and connected between the first plate and the second plate, a second sieve hole or a second guide hole in the same direction as the liquid flow is opened on the lower inclined plate, and a third guide hole in the same direction as the liquid flow is opened on the upper inclined plate.

[0006] Preferably, the connection between the upper inclined plate and the lower inclined plate is a rounded corner connection.

[0007] Preferably, the fillet radius R1 at the fillet connection position is ≥30mm.

[0008] Preferably, the angle between the lower inclined plate and the horizontal plane is α, 15°≤α≤90°; the angle between the upper inclined plate and the horizontal plane is β, 0°≤β≤60°.

[0009] Preferably, the horizontal length of the upper inclined plate is l, where 20mm ≤ l ≤ 300mm.

[0010] Preferably, in the direction from the first plate to the second plate, the high point of the lower inclined plate is higher than the high point of the next lower inclined plate.

[0011] Preferably, the diameters of the first guide hole, the second guide hole, and the third guide hole are 4-12 mm, and the diameters of the first sieve hole and the second sieve hole are 3-8 mm.

[0012] Preferably, the connection between the second plate and the corresponding lower inclined plate is a rounded corner connection.

[0013] Preferably, the fillet radius R1 at the fillet connection position is ≥30mm. Beneficial effects

[0014] 1. The present invention adopts a stepped layout, which greatly reduces the liquid level difference in the direction of liquid flow, which is conducive to the uniform distribution of liquid and gas phases, provides better gas-liquid contact conditions, and significantly improves the mass transfer efficiency of the tray.

[0015] 2. The tray uses a zoned perforation method, with guide holes at the higher liquid level position of the traditional tray and ordinary sieve holes at the lower liquid level position, which can further reduce the liquid level difference on the tray.

[0016] 3. By adopting a method of staggering the liquid receiving tray and the tower tray in height, and opening a lateral hole on the lower side of the inlet weir plate, the liquid phase is driven by the gas guiding effect, and the flow dead zone after the inlet weir plate is activated, which effectively improves the mass transfer area of ​​the tower tray. Attached Figure Description

[0017] Figure 1 This is a longitudinal sectional view of a stepped guide sieve tray according to the present invention.

[0018] Figure 2 for Figure 1 A top-view structural diagram;

[0019] Figure 3 This is a schematic diagram showing some structural parameters of the tray in this invention;

[0020] The markings in the diagram are: 1. Inlet weir plate, 101. Lateral hole, 2. Liquid receiving tray, 3. Tray plate, 301. First guide hole, 302. First plate, 303. Second sieve hole, 304. Lower inclined plate, 305. Upper inclined plate, 306. Third guide hole, 307. Second plate, 308. First sieve hole, 4. Outlet weir plate, 5. Tower wall. Detailed Implementation

[0021] like Figure 1 and Figure 2 As shown, a stepped guide sieve tray of the present invention includes an inlet weir plate 1, a tray plate 3, and an outlet weir plate 4 arranged in a stepped manner from top to bottom and from left to right in the tower wall 5. The tray plate 3 includes a first flat plate 302 arranged from left to right, a plurality of downwardly inclined plates 304, an upwardly inclined plate 305, and a second flat plate 307 arranged alternately. The first flat plate 302 is fixedly connected to the bottom right side of the inlet weir plate 1. A liquid receiving tray 2 is connected to the middle left side of the inlet weir plate 1, and a plurality of lateral holes 101 are formed on the inlet weir plate 1 between the liquid receiving tray 2 and the first flat plate 302. The liquid receiving tray 2 is slightly higher than the tray plate 3 in the height direction, and the lateral holes 101 enhance gas-liquid mass transfer and promote liquid phase flow. The second flat plate 307 is fixedly connected to the middle of the outlet weir plate 4.

[0022] Based on the above structure, the present invention forms region I on the first plate 302, region II on the lower inclined plate 304, region III on the upper inclined plate 305, and region IV on the second plate 307. The tray 3 provided by the present invention employs different opening methods in different regions. Region I has a first guide hole 301, with the opening direction consistent with the liquid flow direction; Region II has a common second sieve hole 303 or a second guide hole, with the opening direction consistent with the liquid flow direction when it is a second guide hole; Region III has a third guide hole 306, with the opening direction consistent with the liquid flow direction; Region IV has a common second sieve hole 303. The diameters of the first guide hole 301, the second guide hole, and the third guide hole 306 are 4-12 mm, and the diameters of the first sieve hole 308 and the second sieve hole 303 are 3-8 mm.

[0023] In regions I and III, the first guide hole 301 and the third guide hole 306 serve to promote liquid phase flow and reduce the liquid level difference on the plate. In region II, a second guide hole or a regular second sieve hole 303 can be used. Using a second guide hole promotes liquid phase flow and avoids the formation of flow dead zones in the recesses. Using a regular second sieve hole 303 only serves to facilitate the flow of the working gas phase. In region IV, the liquid phase does not need to flow on the plate; it only needs to overflow under the impetus of the gas phase and the liquid level difference. Therefore, only a regular first sieve hole 308 is required.

[0024] The main workflow of this invention is as follows:

[0025] The liquid phase flows from the upper tray to the receiving tray 2, enters region I through the inlet weir 1, and flows to regions II and III under the action of the gas phase driving force at the first guide hole 301 (the gas phase flows to the upper tray through the corresponding sieve holes and guide holes) and the liquid level difference. Then, under the gas phase driving force at the second guide hole in region II and the third guide hole 306 in region III, it flows downwards to region IV and, under the action of the liquid level difference, flows through the outlet weir 4 to enter the next layer. The gas phase flows upwards through the openings in regions I, II, III, and IV, and the opening on the lower side of the inlet weir 1, respectively, making gas-liquid contact with the liquid phase on the tray. The openings in regions I, II, and III, and the opening on the lower side of the inlet weir 1, provide flow driving force to the liquid phase, promoting the renewal of the gas-liquid contact surface and enhancing gas-liquid mass transfer.

[0026] To prevent the liquid phase from forming vortices and dead zones near the recessed connection between the lower inclined plate 304 and the upper inclined plate 305, a rounded connection is made at the joint between the lower inclined plate 304 and the upper inclined plate 305. Additionally, when the second guide hole is opened in region II, the bottom portion of the second guide hole should guide the gas phase towards the recessed connection to avoid forming a dead zone. The connection between region IV and the lower inclined plate 304 is rounded.

[0027] Structural parameters: such as Figure 3 As shown, the angle α between the lower inclined plate 304 and the horizontal plane is 15°≤α≤90°; the angle β between the upper inclined plate 305 and the horizontal plane is 0°≤β≤60°; the horizontal length l of the upper inclined plate 305 is 20mm≤l≤300mm; the high point A of the lower inclined plate 304 and the high point B of the next lower inclined plate 304 are such that point A is higher than or equal to point B in the height direction. The rounded radius R1 at the connection between the lower inclined plate 304 and the upper inclined plate 305 is ≥30mm, and the rounded radius R2 at the connection between region IV and the lower inclined plate 304 is ≥30mm.

[0028] The following comparison is made between a specific embodiment of the present invention and a conventional sieve tray:

[0029] The plexiglass tower has an inner diameter of 450mm and is equipped with both ordinary sieve trays and the tray of this invention. The structural parameters of the ordinary sieve tray are: opening diameter 6mm. The structural parameters of the tray of this invention are: α=30°, β=15°, l=80mm, with two sets of lower inclined plates 304 and upper inclined plates 305. The diameter of the first sieve hole 308 in region IV is 6mm, and regions I, 2, and 3 are all equipped with guide holes with a diameter of 10mm.

[0030] The system was an aqueous glycerol solution-air mixture with a liquid phase viscosity of 0.015 Pa·s. Observation of the gas-liquid phase flow showed that the gas and liquid phases were more uniformly distributed and the gas-liquid contact was better on the trays of this invention. The results are shown in Table 1 below. Table 1. Comparison of gas-liquid two-phase flow patterns on different trays

Claims

1. A stepped guide sieve tray, characterized in that: The system includes an inlet weir plate (1), a tray plate (3), and an outlet weir plate (4) arranged in a stepped manner from top to bottom. A horizontally distributed liquid receiving tray (2) is connected to the middle of the inlet weir plate (1) on the side opposite to the tray plate (3), and lateral holes (101) are spaced apart on the inlet weir plate (1) below the liquid receiving tray (2). The tray plate (3) includes a first plate (302), a second plate (307), an upper inclined plate (305), and a lower inclined plate (304). The first plate (302) is connected to the bottom of the inlet weir plate (1), and a groove is formed on the first plate (302) in the direction of liquid flow. The first guide hole (301) is connected to the second plate (307) and the outlet weir plate (4). The second plate (307) is provided with a first screen hole (308). The number of upper inclined plates (305) and lower inclined plates (304) is multiple. Multiple upper inclined plates (305) and lower inclined plates (304) are staggered and connected between the first plate (302) and the second plate (307). The lower inclined plate (304) is provided with a second screen hole (303) or a second guide hole in the same direction as the liquid flow. The upper inclined plate (305) is provided with a third guide hole (306) in the same direction as the liquid flow.

2. The stepped guide sieve tray as described in claim 1, characterized in that: The connection between the upper inclined plate (305) and the lower inclined plate (304) is a rounded corner connection.

3. A stepped guide sieve tray as described in claim 2, characterized in that: The fillet radius R1 at the fillet connection position is ≥30mm.

4. A stepped guide sieve tray as described in claim 1, characterized in that: The angle between the lower inclined plate (304) and the horizontal plane is α, 15°≤α≤90°; the angle between the upper inclined plate (305) and the horizontal plane is β, 0°≤β≤60°.

5. A stepped guide sieve tray as described in claim 4, characterized in that: The horizontal length of the upper inclined plate (305) is l, 20mm≤l≤300mm.

6. A stepped guide sieve tray as described in claim 4, characterized in that: In the direction from the first plate (302) to the second plate (307), the high point of the lower inclined plate (304) is higher than the high point of the next lower inclined plate (304).

7. A stepped guide sieve tray as described in claim 1, characterized in that: The diameters of the first guide hole (301), the second guide hole, and the third guide hole (306) are 4-12 mm, and the diameters of the first sieve hole (308) and the second sieve hole (303) are 3-8 mm.

8. A stepped guide sieve tray as described in claim 1, characterized in that: The second plate (307) is connected to the corresponding inclined plate (304) with a rounded corner.

9. A stepped guide sieve tray as described in claim 8, characterized in that: The fillet radius R1 at the fillet connection position is ≥30mm.

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