Anti-blocking efficient tower plate structure and manufacturing method

Abstract

The invention relates to the technical field of chemical equipment, in particular to an anti-clogging efficient tower plate structure which comprises a tower plate, and sieve pores are distributed in the tower plate; the flow guide cone is detachably and fixedly connected to the tower plate, the flow guide cone is in a rectangular pyramid shape, each conical surface of the flow guide cone directly faces one sieve hole, a fixing rod is arranged at the bottom of the flow guide cone and comprises a smooth section and a threaded section, the diameter of the smooth section is larger than that of the threaded section, one end of the smooth section is fixedly connected with the flow guide cone, and the other end of the smooth section is fixedly connected with the flow guide cone. Mounting holes matched with the fixing rods are formed in the tower plate. The invention provides an anti-clogging efficient tower plate structure which can effectively dredge blockages on a tower plate and reduce the occurrence rate of tower plate clogging.

Description

Technical Field

[0001] The invention relates to the technical field of chemical equipment, and in particular to an anti-clogging high-efficiency tower plate structure and a manufacturing method thereof. Background Art

[0002] Ammonia distillation tower is a kind of tower that separates ammonia through heating and desorption. The reactor operates at about 103°C. Specifically, direct steam is used as a heating agent in the reactor to make the equilibrium vapor pressure of ammonia on the circulating water surface greater than the partial pressure of ammonia in the heat carrier. In this way, a vapor-liquid two-phase countercurrent contact is formed in the tower, and ammonia is gradually released from the circulating water through the mass transfer and heat transfer process. At the top of the tower, a mixture of ammonia vapor and water vapor is obtained, while at the bottom of the tower, relatively pure circulating water is obtained. The design of the ammonia distillation tower allows ammonia water to flow from top to bottom in the tower, and continuously obtains heat from direct steam. Due to the high volatility of ammonia, the partial pressure of ammonia on the liquid surface increases. When it is greater than the partial pressure of ammonia in the steam, ammonia diffuses into the vapor phase to reduce the ammonia content in the liquid phase, thereby achieving the purpose of ammonia distillation. In this process, ammonia water flows in from the top of the tower and flows down from the holes on the tower plate due to gravity. At the same time, direct steam passes through the sieve holes on the tower plate vertically from bottom to top, and the liquid passes through the tower plate horizontally. The gas and liquid are in full contact on the tower plate to achieve the purpose of heat transfer.

[0003] At present, most of the ammonia distillation towers focus on the selection of tray hole type and gas channel distribution, but ignore the optimization of ammonia distillation efficiency and anti-clogging structure design, so there are the following problems

[0004] Problem 1: Direct steam is introduced into the bottom of the ammonia evaporation tower, and most of the ammonia water introduced is concentrated in the upper part of the tower body, while the lower tower plate is subjected to upward dry blowing of the inlet air, resulting in energy loss. Therefore, this phenomenon leads to reduced ammonia evaporation efficiency and waste of direct steam.

[0005] The second problem is that the plates of the ammonia evaporation tower are prone to blockage, which reduces the efficiency of ammonia evaporation and consumes a lot of manpower for regular cleaning. Summary of the invention

[0006] The purpose of the present invention is to provide an anti-clogging high-efficiency tower plate structure, which can effectively clear the blockage on the tower plate and reduce the occurrence rate of tower plate blockage.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] An anti-clogging high-efficiency tower plate structure, comprising a tower plate, wherein sieve holes are distributed on the tower plate;

[0009] A guide cone is detachably fixedly connected to the tower plate, and the guide cone is in the shape of a quadrangular pyramid, with each cone surface facing a sieve hole.

[0010] Furthermore, a fixing rod is provided at the bottom of the guide cone, and the fixing rod includes a smooth section and a threaded section. The diameter of the smooth section is larger than the diameter of the threaded section. One end of the smooth section is fixedly connected to the guide cone, and a mounting hole matching the fixing rod is provided on the tower plate.

[0011] Furthermore, four sieve holes are spaced between two adjacent guide cones in each row.

[0012] Furthermore, square through holes are provided on both sides of the tower plate, and the side length of the square through holes is the same as the diameter of the sieve holes.

[0013] A method for manufacturing an anti-clogging high-efficiency tower plate, the steps of manufacturing the anti-clogging high-efficiency tower plate are as follows: step 1, manufacturing a tower plate, selecting a tower plate according to design requirements and manufacturing the tower plate into a circular shape, and at the same time, according to the design requirements, the tower plate hole spacing t and the opening rate Making sieve holes on the tower plate, wherein the centers of four adjacent sieve holes are located at the four vertices of a square, and making square through holes on both sides of the tower plate;

[0014] Step 2: Make a guide cone and make threaded mounting holes on the tower plate, where the axis of the threaded mounting hole is located at the center of four adjacent sieve holes.

[0015] The first step is to calculate the guide cone height h w Value

[0016] According to the formula h, the pressure drop of gas passing through the liquid layer is calculated L ,

[0017] h L =β 0 (h w +h ow ) (1)

[0018] Among them, h ow is the height of the diversion fluid head during operation, β 0 Take β as the bubbling factor 0 =3,h L The pressure drop of gas through the liquid layer;

[0019] According to the formula z, the height of the clear liquid layer is calculated L ,

[0020] z L =Ah w +0.31L w (2)

[0021] Among them, L w Liquid flow intensity, the tower plate designed for the present invention is a guide tower plate, so the constant A is taken as 0.9;

[0022] According to the total pressure drop formula hp ,

[0023] h p =h c +h L +jz L (3)

[0024] Where j is the inflation factor, j = 0.7;

[0025] According to the total pressure drop of the tower plate h p Value range and dry plate pressure drop h C The value of h is obtained by formula (3) L +jz L Then substitute formula (1) and formula (2) into formula (3),

[0026] Get the first h w The range of values,

[0027] After adding the guide device, the tower plate sieve hole will leak liquid, but when the hole velocity reaches a certain level, there will be no leakage. om Perform calculations,

[0028]

[0029] According to the design requirements, the reasonable leakage point hole speed W 0m ≤6m / s;

[0030] Substituting formula (1) and formula (2) into formula (4), we can get

[0031]

[0032] Get the second h w The range of values,

[0033] In the formula, The present invention aims at the guide plate flow coefficient being a constant C 0 =0.779,γ v Gas phase gravity at work, γ L Liquid phase density during operation, liquid-gas ratio is usually is the plate opening ratio,

[0034] To ensure that no leakage occurs, the actual hole velocity W should be guaranteed. 0 Larger and makes the actual hole speed W 0 The hole speed W of the leakage point 0m The stability coefficient relationship is

[0035] By two h w Confirm the range value of hw Final value;

[0036] The second step is to calculate the length r of the bottom side of the guide cone. w According to the design requirements, the length of the bottom side of the guide cone is r w Ratio to the plate hole spacing r w =0.6t~0.8t;

[0037] The third step is to determine the diameter of the threaded section at the bottom of the guide cone. The diameter is selected to be 0.4 to 0.6 times the length of the bottom edge of the guide cone.

[0038] The fourth step is to make tower plates and guide cones according to the calculated values.

[0039] Step three: installing the manufactured guide cone on the tower plate.

[0040] The beneficial effects of the present invention are:

[0041] According to the characteristics of the guide trapezoidal float valve, the guide distribution and arrangement on the tower plate is such that a guide device is installed between every four holes in a row. This not only reduces the formation time of the liquid layer on the lower tower plate, but also ensures that the ammonia water stays on the tower plate for a sufficient time to effectively evaporate the ammonia gas. It also facilitates the regular replacement of the guide device, increases flexibility and variability. During operation, when the ammonia water flows down from above, an active flow fluid can be formed due to the effect of the guide cone, which can quickly flow into the side sieve holes and flow into the next layer. The four-sided pyramid type corresponds to the four side sieve holes, which has better benefits. At the same time, when particulate matter or other impurities are easily mixed on the tower plate and cause blockage, the guide effect of the guide cone can make the newly formed particles flow to the lower pedal, reducing the number of tower plates that need to be replaced due to blockage. Square guide holes with the side length of the sieve hole diameter are designed on both sides of the tower plate to facilitate clearing of blockages. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of the guide cone structure of the present invention.

[0043] Figure 2 Schematic diagram of the structure looking down after the guide cone is installed on the tower plate.

[0044] Figure 3 This is a cloud diagram of the fluid velocity at the bottom of the ammonia distillation tower with two types of tower plates.

[0045] Figure 4 Line graph of the fluid velocity at the bottom of the tower after using two tower plates. DETAILED DESCRIPTION

[0046] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments.

[0047] Combination Figures 1-2It can be seen that an anti-clogging and efficient tray structure includes:

[0048] A tower plate 10, wherein sieve holes 101 are distributed on the tower plate 10;

[0049] The guide cone 20 is detachably fixedly connected to the tower plate 10 . The guide cone 20 is in the shape of a quadrangular pyramid, and each cone surface is directly opposite to a sieve hole 101 .

[0050] Furthermore, a fixing rod 201 is provided at the bottom of the guide cone 20, and the fixing rod 201 includes a smooth section 2011, one end of the smooth section 2011 is fixedly connected to the free end of the guide cone 20 and fixedly connected to a threaded section 2012, the diameter of the smooth section 2011 is larger than the diameter of the threaded section 2012, and a mounting hole matching the fixing rod 201 is provided on the tower plate 10.

[0051] Furthermore, four sieve holes 101 are spaced between two adjacent guide cones 20 in each row.

[0052] Furthermore, square through holes 102 are provided on both sides of the tower plate 10 , and the side length of the square through hole 102 is the same as the diameter of the sieve hole 101 .

[0053] A method for manufacturing an anti-clogging high-efficiency tower plate, the steps for manufacturing the anti-clogging high-efficiency tower plate are as follows:

[0054] Step 1: Make the tower plate 10. Select the tower plate 10 according to the design requirements and make the tower plate 10 into a circle. At the same time, according to the design requirements, the tower plate hole spacing t and the opening rate A sieve hole 101 is made on the tower plate 10, wherein the centers of four adjacent sieve holes 101 are located at four vertices of a square, and square through holes 102 are made on both sides of the tower plate 10;

[0055] Step 2: Make the guide cone 20 and make threaded mounting holes on the tower plate 10, wherein the axis of the threaded mounting holes is located at the center of four adjacent sieve holes 101.

[0056] The first step is to calculate the height h of the guide cone 20 w Value

[0057] According to the formula h, the pressure drop of gas passing through the liquid layer is calculated L ,

[0058] h L =β 0 (h w +h ow ) (1)

[0059] Among them, h ow is the height of the diversion fluid head during operation, β 0Take β as the bubbling factor 0 =3,h L The pressure drop of gas through the liquid layer;

[0060] According to the formula z, the height of the clear liquid layer is calculated L ,

[0061] z L =Ah w +0.31L w (2)

[0062] Among them, L w Liquid flow intensity, the tower plate designed for the present invention is a guide tower plate, so the constant A is taken as 0.9;

[0063] According to the total pressure drop formula h p ,

[0064] h p =h c +h L +jz L (3)

[0065] Where j is the inflation factor, j = 0.7;

[0066] According to the total pressure drop of the tower plate h p Value range and dry plate pressure drop h C The value of h is obtained by formula (3) p +jz L Then substitute formula (1) and formula (2) into formula (3),

[0067] Get the first h w The range of values,

[0068] After adding the guide device, the tower plate sieve hole will leak liquid, but when the hole velocity reaches a certain level, there will be no leakage. om Perform calculations,

[0069]

[0070] According to the design requirements, the reasonable leakage point hole speed W 0m ≤6m / s;

[0071] Substituting formula (1) and formula (2) into formula (4), we can get

[0072]

[0073] Get the second h w The range of values,

[0074] In the formula, The present invention aims at the guide plate flow coefficient being a constant C 0 =0.779,γ v Gas phase gravity at work, γ L Liquid phase density during operation, liquid-gas ratio is usually is the plate opening ratio,

[0075] To ensure that no leakage occurs, the actual hole velocity W should be guaranteed. 0 Larger and makes the actual hole speed W 0 The hole speed W of the leakage point 0m The stability coefficient relationship is

[0076] By two h w Confirm the range value of h w Final value;

[0077] The second step is to calculate the length r of the bottom side of the guide cone 20 w According to the design requirements, the bottom side length of the guide cone 20 is r w Ratio to the plate hole spacing r w =0.6t~0.8t;

[0078] The third step is to determine the diameter of the threaded section 2012 at the bottom of the guide cone 20, which is selected to be 0.4 to 0.6 times the length of the bottom side of the guide cone.

[0079] The fourth step is to manufacture the tower plate 10 and the guide cone 20 according to the calculated values;.

[0080] Step three: installing the manufactured guide cone 20 on the tower plate 10.

[0081] Specific calculation process

[0082] According to the selected tower plate hole spacing t = 30mm, the opening rate First, the side length of the guide device can be calculated. Because the hole spacing constraint also needs to play a guiding role, the bottom side length is designed to be smaller than the hole spacing. If the ratio is too small, the diversion effect will be minimal. If the ratio is too large, leakage will occur, which will reduce the mass transfer efficiency. The ratio is usually 0.6 to 0.8, so the width r of the guide device can be calculated. w It can be around 21mm.

[0083] According to actual working conditions and experimental requirements, the liquid flow intensity is usually L w =15~35m 3 / m·h. At the same time, the liquid layer height on most plates is h ow=35~45mm, A=0.9, j is the inflation factor, j=0.7, β 0 Take β as the bubbling factor 0 =3.

[0084] Since the dry plate pressure drop is only related to the tower plate type and has no relationship with the guide cone height, the actual hole velocity is usually W according to the working conditions. 0 =5~9m / s, the dry plate pressure drop is usually h C =About 51.5Pa.

[0085] According to the pressure drop of the tower plate, the pressure drop of each plate of the plate tower ranges from 300-400Pa because the process requirements must be taken into consideration. The specific pressure drop needs to be determined according to the process conditions.

[0086] According to formula (3), the total pressure drop of the tower plate is the sum of the dry plate pressure drop, the clear liquid layer pressure drop and the clear liquid layer height. From this formula (3), we can know that 248.5 <h L +jz L <348.5Pa, according to the plate pressure drop range, the above formula (1) (2) and the known h ow and L w The guide cone height h can be obtained w The relationship is 248.5<β 0 (h w +h ow )+j[Ah w +0.31L w ]<348.5, from which we can deduce that 248.5<3.63h w +3h 0w +0.217L w <348.5, now substitute it into the calculation to get the guide cone height h w The first time h w The reasonable range is 35mm to 62mm.

[0087] When the actual hole speed W 0 =5~9m / s according to the actual hole speed and W 0m The stability coefficient relationship is Reasonable leakage point hole speed W 0m ≤6m / s, the hole velocity w at the leakage point can be obtained by formula (4) om With h L and z L There is a relationship, and then through formula (1) and (2), W 0m ≤6m / s The relationship between the height of the guide cone and the hole velocity at the leakage point can be deduced as follows: After substituting the data, the second h is calculated w The reasonable range is h w ≤48mm.

[0088] Combined twice h w The range value is 44mm for the guide cone height.

[0089] At the same time, according to the calculated guide cone height of 44mm and width r w At 21mm, a guide cone was made and installed on the tower plate 10. The CFD-Post simulation was used to calculate the fluid flow rate at the bottom of the tower when ammonia water flows through a tower plate with a guide device and a common tower plate at an initial velocity of 1m / s. Using the established solution model, a numerical simulation of the ammonia distillation tower with high-efficiency tower plates and common tower plates was performed. The tower bottom was used as the observation surface, and post-processing was used to obtain the velocity cloud map of the fluid flow field at the bottom of the tower and the distribution of the velocity vector. Figure 3 (a) and (b) are the velocity distribution cloud diagrams of the longitudinal section at the bottom of the tower when ammonia is evaporated by two types of tower plates. (a) is the velocity cloud diagram of the bottom of the tower with improved high-efficiency guide tower plates, and (b) is the velocity cloud diagram of the bottom of the tower with ordinary tower plates.

[0090] In order to make the data more accurate, the average velocity of the fluid in any diameter section at the bottom of the tower is observed. The average velocity line graph is as follows: Figure 4 As shown, (a) is an improved high-efficiency guide tray and (b) is an ordinary tray. Through the broken line graph, it can be intuitively concluded that the average flow rate of the fluid at the bottom of the high-efficiency tray is 0.18m / s, and the flow rate in most areas is above 0.15m / s, while the average flow rate of the fluid at the bottom of the ordinary tray is about 0.1m / s, and the average flow rate in a few bottom areas can reach 0.15m / s. Through the broken line graph and calculation analysis, it can be fully seen that the guide device designed by the present invention has the effect of significantly accelerating the formation time of the liquid layer of the lower tray, fully reducing the time of air evaporation of the lower tray, and effectively reducing energy loss.

[0091] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly used in other related technical fields, are similarly included in the patent protection scope of the present invention.

Claims

1. An anti-clogging high-efficiency tray structure, characterized in that: include, A tower plate (10), wherein sieve holes (101) are distributed on the tower plate (10); A guide cone (20), wherein the guide cone (20) is detachably fixedly connected to the tower plate (10), and the guide cone (20) is in the shape of a quadrangular pyramid, with each cone surface facing a sieve hole (101).

2. The anti-clogging high-efficiency tray structure and manufacturing method according to claim 1, characterized in that: A fixing rod (201) is arranged at the bottom of the guide cone (20), the fixing rod (201) comprises a smooth section (2011) and a threaded section (2012), the diameter of the smooth section (2011) is larger than the diameter of the threaded section (2012), one end of the smooth section (2011) is fixedly connected to the guide cone (20), and a countersunk threaded hole matching the fixing rod (201) is arranged on the tower plate (10).

3. The anti-clogging high-efficiency tray structure and manufacturing method according to claim 2, characterized in that: Four sieve holes (101) are spaced between two adjacent guide cones (20) in each row.

4. The anti-clogging high-efficiency tray structure and manufacturing method according to claim 3, characterized in that: Square through holes (102) are arranged on both sides of the tower plate (10), and the side length of the square through hole (102) is the same as the diameter of the sieve hole (101).

5. A method for manufacturing an anti-clogging high-efficiency tray, comprising manufacturing an anti-clogging high-efficiency tray as claimed in claim 4, characterized in that: The steps are as follows, Step 1: Make the tower plate (10). Make the tower plate (10) into a circular shape according to the design requirements. At the same time, the tower plate hole spacing t and the opening rate are adjusted according to the design requirements. Making sieve holes (101) on the tower plate (10), wherein the centers of four adjacent sieve holes (101) are located at four vertices of a square, and making square through holes (102) on both sides of the tower plate (10); Step 2: making a guide cone (20) and making threaded mounting holes on the tower plate (10), wherein the axis of the threaded mounting holes is located at the center of four adjacent sieve holes (101). The first step is to calculate the height h of the guide cone (20) w Value According to the formula h, the pressure drop of gas passing through the liquid layer is calculated L , h L =β0(h w +h ow ) (1) Among them, h ow is the height of the diversion liquid head during operation, β0 is the bubbling factor, β0=3, h L The pressure drop of gas through the liquid layer; According to the formula z, the height of the clear liquid layer is calculated L , <h2 style=";text-align:left;direction:ltr">z<h2 style=";text-align:left;direction:ltr"> L <h2 style=";text-align:left;direction:ltr"> (Ah)<h2 style=";text-align:left;direction:ltr"> w <h2 style=";text-align:left;direction:ltr"> +0.31L<h2 style=";text-align:left;direction:ltr"> w <h2 style=";text-align:left;direction:ltr"> (2) Among them, L w Liquid flow intensity, the tower plate designed for the present invention is a guide tower plate, so the constant A is taken as 0.9; According to the total pressure drop formula h p , h p =h c +h L +jz L (3) Where j is the inflation factor, j = 0.7; According to the total pressure drop of the tower plate h p Value range and dry plate pressure drop h C The value of h is obtained by formula (3) L +jz L Then substitute formula (1) and formula (2) into formula (3), Get the first h w The range of values, After adding the guide device, the tower plate sieve hole will leak liquid, but when the hole velocity reaches a certain level, there will be no leakage. om Perform calculations, According to the design requirements, the reasonable leakage point hole speed W 0m ≤6m / s; Substituting formula (1) and formula (2) into formula (4), we can obtain Get the second h w The range of values, In the formula, The flow coefficient of the guide plate is constant C0 = 0.779, γ v Gas phase gravity at work, γ L Liquid phase density during operation, liquid-gas ratio is usually is the plate opening ratio, To ensure that no leakage occurs, the actual hole velocity W should be guaranteed. O The actual hole velocity W0 is larger than the hole velocity W at the leakage point. 0m The stability coefficient relationship is By two h w Confirm the range value of h w Final value; The second step is to calculate the length r of the bottom side of the guide cone (20). w , According to design requirements, the bottom side length r of the guide cone (20) w Ratio to the plate hole spacing r w =0.6t~0.8t; The third step is to determine the diameter of the threaded section (2012) at the bottom of the guide cone (20), which is selected to be 0.4 to 0.6 times the length of the bottom side of the guide cone. The fourth step is to manufacture the tower plate (10) and the guide cone (20) according to the calculated values; Step 3: Install the manufactured guide cone (20) on the tower plate (10).

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