Uniform point mass transfer tower tray

Abstract

The utility model discloses a uniform-point mass transfer tower tray. The uniform-point mass transfer tower tray comprises an I-type tower tray and an II-type tower tray, the I-type tower trays and the II-type tower trays are alternately mounted in the tower body at intervals along the layer direction; a plurality of mass transfer units and a plurality of downcomer units are arranged on each I-type tower tray and each II-type tower tray; a mass transfer unit is arranged on each airflow hole formed in each I-shaped tower tray and each II-shaped tower tray; a downcomer unit is arranged on each plate hole formed in each I-shaped tower tray and each II-shaped tower tray; the mass transfer unit is matched with the downcomer unit on the upper layer, and the downcomer unit is matched with the mass transfer unit on the lower layer. The liquid falling units and the mass transfer units are in one-to-one correspondence to form an independent micro mass transfer unit, the whole tray can be used as a combination of a plurality of micro mass transfer units, and the liquid-phase flow and the gas-liquid mass transfer efficiency among the micro mass transfer units are not mutually influenced, so that the mass transfer of the whole tray is more uniform, and the mass transfer efficiency is improved.

Description

Technical Field

[0001] The utility model relates to heat transfer and mass transfer equipment in chemical engineering, in particular to an even-point mass transfer tower plate used for heat transfer and mass transfer separation in chemical engineering. Background Art

[0002] With the gradual large-scale and collectivized development of chemical equipment such as petrochemicals, coal chemicals and synthetic ammonia, the production scale of tower plates, as an important mass transfer and heat transfer equipment used in distillation, absorption, stripping, etc., is getting larger and larger, and the tower diameter is also increasing proportionally. However, simply increasing the tower diameter has increasingly exposed its shortcomings such as large liquid phase back mixing, low tower plate utilization, and poor mass transfer effect.

[0003] People have always focused on the development of monomer mass transfer components, such as bubble trays, float valves, fixed valves, tongue-shaped trays, etc. For example, the document with application number 201620371279.9 discloses a tongue-shaped tray, which is wavy, forming wave crests and troughs, with holes on the two side walls of the wave crests, and tongues are provided at the corresponding holes to avoid the airflows blown out of the two adjacent tray holes from affecting each other. The document with application number 00116714.6 discloses an obliquely arranged oblique hole tray, the sieve holes on the tray are inclined upward at a certain angle, so that the main gas below the tray flows out of the sieve holes to form a partial velocity that drives the liquid flow, in order to improve the airflow distribution and gas-liquid contact effect. Document No. 202321168642.3 discloses a new type of guided ladder-type float valve tower tray, whose structure is that multiple groups of float valves are arrayed on the tower tray, and each group of float valves is separated by an overflow weir. The fluid flowing out from the upper downcomer needs to cross multiple groups of overflow weirs on the tower tray before it can flow out from the downcomer on this layer and enter the next tower tray. This type of tower tray has the characteristics of long process flow and long residence time.

[0004] However, although the improvements and innovations of the above-mentioned monomer mass transfer components have improved the point efficiency of the tower plate to a certain extent and improved the efficiency of the entire plate, it cannot fundamentally solve the problem of decreased tower plate efficiency in the entire mass transfer area caused by factors such as cross-flow, biased flow, stagnation and liquid level gradient.

[0005] In terms of downcomer design, in previous downcomer designs, the impact of liquid volume on the number and distribution of downcomers was mostly considered. However, its impact on the overall mass transfer efficiency has rarely been reported. For example, the document with application number 202211455933.0 discloses a high-efficiency, large-flux multi-downcomer tray, which considers the design problem from the universality of the liquid flow rate of the downcomer. The document with application number 202222378869.2 discloses a suspended downcomer, including a tube body and a guide V-shaped plate. The V-shaped plate is inverted and installed at the bottom of the downcomer, with holes on both sides to solve the liquid phase retention phenomenon in the downcomer. The document with application number 200910134260.7 discloses a multi-downcomer tray, whose main structure is a plurality of rectangular downcomers and extension elements. The tray is a single-layer structure. The structure of the tray has a liquid phase backmixing phenomenon, resulting in a low efficiency of the tray. Document No. 202111590149.6 discloses distillation tower trays, plate-type distillation towers and their applications, in order to allow gas and liquid in the downcomer to contact and increase the mass transfer area.

[0006] In summary, there are few reports on the effect of downcomers on the overall mass transfer efficiency. However, when multiple groups of airflow ascending channels share a downcomer, during the flow of the liquid phase from the outlet of the upper downcomer to the inlet of the lower downcomer, the liquid phase in contact with the rising airflow at the outlet has a large gas-liquid mass transfer driving force. As the liquid phase flows, the mass transfer driving force gradually decreases, and the mass transfer efficiency becomes lower and lower, which ultimately leads to low overall efficiency. Therefore, the traditional downcomer design, whether it is a single-root design or a multi-downcomer design, cannot overcome the disadvantage of low overall mass transfer efficiency. This is because traditional theory believes that: the mass transfer efficiency is positively correlated with the length of the liquid flow path, and the longer the path, the higher the mass transfer efficiency. However, experiments have also found that there is an optimal value for the liquid flow path of some systems. Beyond this optimal value, the mass transfer efficiency no longer increases or even decreases due to backmixing. These are issues that have not attracted widespread attention before. Utility Model Content

[0007] In view of the deficiencies in the prior art, the technical problem to be solved by the utility model is to provide a uniform point mass transfer tower plate.

[0008] The utility model solves the technical problem by providing a uniform point mass transfer tower tray, which is characterized by comprising a type I tower tray and a type II tower tray; the type I tower tray and the type II tower tray are alternately installed in the tower body along the layer direction;

[0009] Each type I tray and each type II tray are provided with a plurality of mass transfer units and a plurality of downcomers; each air flow hole opened on each type I tray and each type II tray is provided with a mass transfer unit; each plate hole opened on each type I tray and each type II tray is provided with a downcomer unit; the mass transfer unit cooperates with the downcomer unit on the upper layer, and the downcomer unit cooperates with the mass transfer unit on the lower layer;

[0010] The mass transfer unit comprises a riser, an air baffle, a flow restricting tube, a mixing tank, an annular liquid flow channel, an annular gas channel, an air baffle and an air outlet;

[0011] The riser is fixed on the type I tower plate and the type II tower plate, and is located at the air flow hole; the air baffle is fixed on the type I tower plate and the type II tower plate, and is nested on the outside of the riser; a plurality of air outlet holes are opened in the circumferential direction at the lower part of the air baffle; an annular air baffle plate is fixed to the middle part of the air baffle along the circumference of the air baffle, and is located above the air outlet hole; the mixing tank is fixed on the type I tower plate and the type II tower plate, and is located on the outside of the annular air baffle plate; an annular gas channel is formed between the annular air baffle plate, the mixing tank and the type I tower plate or the type II tower plate; the outer wall of the flow limiting tube is fixed to the inner wall of the mixing tank through a connecting piece, and is located on the inner side of the mixing tank and above the air baffle plate; an annular liquid flow channel is formed between the lower end of the flow limiting tube and the air baffle plate.

[0012] Compared with the prior art, the beneficial effects of the utility model are:

[0013] (1) The downcomer unit of the utility model corresponds one-to-one with the mass transfer unit to form an independent micro mass transfer unit. The entire tower plate can be regarded as a combination of multiple micro mass transfer units. The liquid phase flow and gas-liquid mass transfer efficiency between the micro mass transfer units do not affect each other, thereby making the mass transfer of the entire tower plate more uniform and improving the mass transfer efficiency.

[0014] (2) Set up average point mass transfer, with one-to-one correspondence between the downcomer unit and the mass transfer unit. The liquid phase flow path on the tray is shorter, so that the liquid phase on the plate flows in a manner closer to plug flow, reducing the influence of the bow zone on the flow, making the gas-liquid distribution more uniform, and the gas-liquid mass transfer driving force greater, avoiding the difference in mass transfer driving force caused by the different lengths of the liquid path, and limiting the back mixing of the liquid phase on the tray to the maximum extent. The bubbling area on the tray is used to directly receive the liquid, which increases the gas phase operating load.

[0015] (3) The utility model improves the gas-liquid mass transfer contact structure of the mass transfer unit, so that the gas phase passes through the riser at high speed, and the liquid phase is torn into pieces under the action of high-speed disturbance to form fine particle droplets, thereby increasing the gas-liquid mass transfer contact area and ultimately improving the mass transfer efficiency. The mass transfer unit strengthens the gas-liquid contact mass transfer effect and improves the mass transfer efficiency.

[0016] (4) Through this downdraft mass transfer tray system, the mass transfer efficiency is greatly improved, the driving force of mass transfer at different positions on the same tray is basically the same, and the mass transfer effect is relatively uniform; the liquid phase load of the tray is significantly enhanced, especially when a large liquid-to-gas ratio is used; the operating flexibility is also significantly greater.

[0017] (5) The bubbling area on the tower plate is used to directly receive the liquid. The liquid phase flowing out of the downcomer directly falls on the mass transfer unit in the bubbling area. No separate downcomer area is set on the tower plate, which increases the effective utilization area and improves the gas phase operation load.

[0018] (6) The distributed layout of the downcomer makes the liquid phase more evenly distributed on the tower plate, effectively eliminating the liquid level difference, and the gas phase is more evenly distributed, which is conducive to mass transfer.

[0019] (7) The gas-liquid two-phase mass transfer occurs not only in the horizontal direction of the tower plate, but also in the vertical direction. The contribution of the high-altitude space to the mass transfer is effectively utilized, which is undoubtedly a huge advantage over the traditional mass transfer that only utilizes the horizontal direction.

[0020] (8) The utility model is applicable to all working conditions with a liquid-to-gas ratio, and is particularly applicable to working conditions with a large liquid-to-gas ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a cross-sectional view of two adjacent layers of tower trays of the utility model;

[0022] Figure 2 It is a top view of the I-type tower tray of the utility model;

[0023] Figure 3 It is a top view of the II type tray of the utility model;

[0024] Figure 4 It is a cross-sectional view of the mass transfer unit of the utility model;

[0025] Figure 5 It is a cross-sectional view of the downcomer unit of the utility model.

[0026] In the figure: tower body 1, type I tower tray 2, type II tower tray 3, mass transfer unit 4, downcomer unit 5, air flow holes 6, plate holes 7;

[0027] Riser 401, air baffle 402, flow limiting tube 403, mixing tank 404, annular liquid flow channel 405, annular gas channel 406, air baffle 407, air outlet 408;

[0028] Overflow weir 501, downcomer 502, downcomer 503. DETAILED DESCRIPTION

[0029] The specific embodiments of the present invention are given below. The specific embodiments are only used to further illustrate the present invention in detail and do not limit the protection scope of the claims of the present invention.

[0030] The utility model provides a uniform point mass transfer tower tray, which is characterized by comprising a type I tower tray 2 and a type II tower tray 3; the type I tower tray 2 and the type II tower tray 3 are alternately installed in a tower body 1 along the direction of the layer;

[0031] Each type I tray 2 and each type II tray 3 are provided with a plurality of mass transfer units 4 and a plurality of downcomers 5; each air flow hole 6 opened on each type I tray 2 and each type II tray 3 is provided with a mass transfer unit 4; each plate hole 7 opened on each type I tray 2 and each type II tray 3 is vertically provided with a downcomer 5, and the downcomers 5 are parallel to each other; the mass transfer unit 4 cooperates with the downcomer 5 on the upper layer (that is, the center line of the mass transfer unit 4 is coaxial with the center line of the downcomer 5). The downcomer unit 5 cooperates with the mass transfer unit 4 at the lower layer (i.e., the mass transfer unit 4 on each type I tray 2 cooperates with the downcomer unit 5 on the type II tray 3 at the upper layer, the downcomer unit 5 on each type I tray 2 cooperates with the mass transfer unit 4 on the type II tray 3 at the lower layer, the downcomer unit 5 on each type II tray 3 cooperates with the mass transfer unit 4 on the type I tray 2 at the lower layer, and the mass transfer unit 4 on each type II tray 3 cooperates with the downcomer unit 5 on the type I tray 2 at the upper layer);

[0032] The mass transfer unit 4 includes a riser 401, a gas shield 402, a flow limiting tube 403, a mixing tank 404, an annular liquid flow channel 405, an annular gas channel 406, an air shield 407 and an air outlet 408;

[0033] The riser 401 is fixed on the type I tower plate 2 and the type II tower plate 3, and is located at the air flow hole 6; the air shield 402 is fixed on the type I tower plate 2 and the type II tower plate 3, and is nested on the outer side of the riser 401, and is used to block the gas phase in the riser 401; the lower part of the air shield 402 is provided with a plurality of air outlet holes 408 along the circumferential direction; the annular air shield plate 407 is fixed to the middle part of the air shield 402 along the circumferential direction of the air shield 402, and is located above the air outlet hole 408, and the air shield plate 407 prevents the kinetic energy of the gas from being too large and thus from limiting the flow The gas escapes from the tube 403; the mixing tank 404 is fixed on the type I tower plate 2 and the type II tower plate 3, and is located on the outside of the annular air baffle plate 407; an annular gas channel 406 is formed between the annular air baffle plate 407, the mixing tank 404 and the type I tower plate 2 or the type II tower plate 3; the outer wall of the flow limiting tube 403 is fixed to the inner wall of the mixing tank 404 through a connecting piece, and is located on the inner side of the mixing tank 404 and above the air baffle plate 407; an annular liquid flow channel 405 is formed between the lower end of the flow limiting tube 403 and the air baffle plate 407.

[0034] Preferably, the opening arrangement of the air flow holes 6 and the plate holes 7 on the type I tower tray 2 and the type II tower tray 3 are both in the form of regular triangles, rectangles or isosceles triangles.

[0035] Preferably, the outer diameter of the air shield 402 is 1.1 to 1.5 times (preferably 1.2 times) the outer diameter of the riser 401 .

[0036] Preferably, a plurality of air outlet holes 408 are evenly arranged around the air shield 402; the shape of the air outlet holes 408 is a triangle, a trapezoid or a rectangle.

[0037] Preferably, the outer diameter of the air baffle 407 is 1 to 1.5 times (preferably 1.2 times) the outer diameter of the flow limiting tube 403 , the outer diameter of the mixing pool 404 is 1.1 to 1.5 times (preferably 1.2 times) the outer diameter of the flow limiting tube 403 , and the outer diameter of the mixing pool 404 is larger than the outer diameter of the air baffle 407 .

[0038] Preferably, the height of the mixing pool 404 is higher than the lower end surface of the flow limiting tube 403 .

[0039] Preferably, the height of the annular liquid flow channel 405 is 10% to 50% of the diameter of the flow restricting tube 403 .

[0040] Preferably, the downcomer unit 5 comprises an overflow weir 501, a downcomer hole 502 and a downcomer 503;

[0041] The lower end of the overflow weir 501 is fixed on the type I tower plate 2 and the type II tower plate 3, and is located at the plate hole 7; the upper end of the downcomer 503 is fixed on the type I tower plate 2 and the type II tower plate 3, and is located at the plate hole 7; the overflow weir 501 and the downcomer 503 are both vertically arranged; a downcomer hole 502 is opened at the bottom of the downcomer 503; the center line of the downcomer hole 502 is collinear with the center line of the corresponding flow limiting tube 403.

[0042] Preferably, the overflow weir 501 is a flat weir or a toothed weir. The overflow weir 501 is a circular overflow weir.

[0043] Preferably, the inner diameter of the overflow weir 501 is 1 to 1.5 times (preferably 1.2 times) the inner diameter of the downcomer 503 .

[0044] Preferably, the opening area of ​​the downcomer hole 502 is 10% to 70% (preferably 20%) of the cross-sectional area of ​​the downcomer 503 .

[0045] The working principle and workflow of the utility model are as follows: the liquid phase obtained after separation on the upper tower plate overflows to the overflow weir 501, enters the downcomer 503 through the plate hole 7, and then falls into the flow limiting tube 403 in the tower plate of this layer through the downcomer hole 502. The liquid phase in the flow limiting tube 403 flows into the mixing tank 404 through the annular liquid flow channel 405 at the bottom of the flow limiting tube 403. At the same time, the gas phase from the lower tower plate enters the riser 401 through the air flow holes 6 on the tower plate, is blocked by the air shield 402, and after deflection, escapes from the air outlet 408 at the bottom of the air shield 402. After being blocked by the air shield plate 407, the gas enters the mixing tank 404 through the annular gas channel 406, and the gas phase and the liquid phase contact and transfer mass and heat in the mixing tank 404; then the gas-liquid mixture overflows from the mixing tank 404, drips on the tower plate to continue mass transfer and heat transfer, and performs gas-liquid separation. After gas-liquid separation, the gas phase enters the upper tower plate, and the liquid phase overflows to the overflow weir 501 of the downcomer unit 5 of the tower plate of this layer, completing a mass transfer process.

[0046] Anything not described in the present invention is applicable to the prior art.

Claims

1. A uniform point mass transfer tray, characterized in that It comprises a type I tower tray (2) and a type II tower tray (3); the type I tower tray (2) and the type II tower tray (3) are installed alternately in the tower body (1) along the layer direction; Each type I tower tray (2) and each type II tower tray (3) is provided with a plurality of mass transfer units (4) and a plurality of downcomer units (5); each air flow hole (6) opened on each type I tower tray (2) and each type II tower tray (3) is provided with a mass transfer unit (4); each plate hole (7) opened on each type I tower tray (2) and each type II tower tray (3) is provided with a downcomer unit (5); the mass transfer unit (4) cooperates with the downcomer unit (5) on the upper layer thereof, and the downcomer unit (5) cooperates with the mass transfer unit (4) on the lower layer thereof; The mass transfer unit (4) comprises a riser (401), an air baffle (402), a flow restricting tube (403), a mixing tank (404), an annular liquid flow channel (405), an annular gas channel (406), an air baffle (407) and an air outlet (408); The riser (401) is fixed on the type I tower tray (2) and the type II tower tray (3) and is located at the air flow hole (6); the air shield (402) is fixed on the type I tower tray (2) and the type II tower tray (3) and is nested on the outer side of the riser (401); a plurality of air outlet holes (408) are opened in the circumferential direction at the lower part of the air shield (402); an annular air shield plate (407) is fixed to the middle part of the air shield (402) along the circumferential direction of the air shield (402) and is located above the air outlet hole (408); a mixing tank (404) is fixed on the type I tower tray (2) and II-type tower trays (3), and are located on the outside of the annular air baffle plate (407); an annular gas channel (406) is formed between the annular air baffle plate (407), the mixing tank (404) and the I-type tower tray (2) or the II-type tower tray (3); the outer wall of the flow limiting tube (403) is fixed to the inner wall of the mixing tank (404) through a connecting piece, and is located on the inner side of the mixing tank (404) and above the air baffle plate (407); an annular liquid flow channel (405) is formed between the lower end of the flow limiting tube (403) and the air baffle plate (407).

2. The average point mass transfer tray according to claim 1, characterized in that: The mass transfer unit (4) on each type I tower tray (2) cooperates with the downcomer unit (5) on the type II tower tray (3) above it, the downcomer unit (5) on each type I tower tray (2) cooperates with the mass transfer unit (4) on the type II tower tray (3) below it, the downcomer unit (5) on each type II tower tray (3) cooperates with the mass transfer unit (4) on the type I tower tray (2) below it, and the mass transfer unit (4) on each type II tower tray (3) cooperates with the downcomer unit (5) on the type I tower tray (2) above it.

3. The average point mass transfer tray according to claim 1, characterized in that: The outer diameter of the air shield (402) is 1.1 to 1.5 times the outer diameter of the riser pipe (401).

4. The average point mass transfer tray according to claim 1, characterized in that: A plurality of air outlet holes (408) are evenly arranged in the circumference of the air shield (402); the air outlet holes (408) are in the shape of a triangle, a trapezoid or a rectangle.

5. The average point mass transfer tray according to claim 1, characterized in that: The outer diameter of the air baffle (407) is 1 to 1.5 times the outer diameter of the flow limiting tube (403), the outer diameter of the mixing tank (404) is 1.1 to 1.5 times the outer diameter of the flow limiting tube (403), and the outer diameter of the mixing tank (404) is greater than the outer diameter of the air baffle (407).

6. The average point mass transfer tray according to claim 1, characterized in that: The height of the mixing pool (404) is higher than the lower end surface of the flow limiting tube (403).

7. The average point mass transfer tray according to claim 1, characterized in that: The height of the annular liquid flow channel (405) is 10% to 50% of the diameter of the flow limiting tube (403).

8. The average point mass transfer tray according to claim 1, characterized in that: The downcomer unit (5) comprises an overflow weir (501), a downcomer hole (502) and a downcomer (503); The lower end of the overflow weir (501) is fixed on the type I tower tray (2) and the type II tower tray (3) and is located at the plate hole (7); the upper end of the downcomer (503) is fixed on the type I tower tray (2) and the type II tower tray (3) and is located at the plate hole (7); the overflow weir (501) and the downcomer (503) are both arranged vertically; a downcomer hole (502) is opened at the bottom of the downcomer (503); the center line of the downcomer hole (502) and the center line of the corresponding flow limiting tube (403) are collinear.

9. The average point mass transfer tray according to claim 8, characterized in that: The overflow weir (501) is a flat weir or a toothed weir.

10. The average point mass transfer tray according to claim 8, characterized in that: The inner diameter of the overflow weir (501) is 1 to 1.5 times the inner diameter of the downcomer (503); the opening area of ​​the downcomer hole (502) is 10% to 70% of the cross-sectional area of ​​the downcomer (503).

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