CN109200614B - Design method of tower plate structure for eliminating gas phase bias flow - Google Patents

Design method of tower plate structure for eliminating gas phase bias flow Download PDF

Info

Publication number
CN109200614B
CN109200614B CN201811234763.7A CN201811234763A CN109200614B CN 109200614 B CN109200614 B CN 109200614B CN 201811234763 A CN201811234763 A CN 201811234763A CN 109200614 B CN109200614 B CN 109200614B
Authority
CN
China
Prior art keywords
gas phase
plate
mass transfer
area
tower plate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201811234763.7A
Other languages
Chinese (zh)
Other versions
CN109200614A (en
Inventor
王俊
周鑫
韶晖
冷一欣
黄春香
孙雪妮
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Changzhou University
Original Assignee
Changzhou University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Changzhou University filed Critical Changzhou University
Priority to CN201811234763.7A priority Critical patent/CN109200614B/en
Publication of CN109200614A publication Critical patent/CN109200614A/en
Application granted granted Critical
Publication of CN109200614B publication Critical patent/CN109200614B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
    • B01D3/14—Fractional distillation or use of a fractionation or rectification column
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
    • B01D3/14—Fractional distillation or use of a fractionation or rectification column
    • B01D3/32—Other features of fractionating columns ; Constructional details of fractionating columns not provided for in groups B01D3/16 - B01D3/30
    • B01D3/324—Tray constructions

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
  • Physical Or Chemical Processes And Apparatus (AREA)

Abstract

The invention discloses a tower plate structure for eliminating gas phase bias flow and a design method thereof, wherein the tower plate structure comprises a mass transfer tower plate, a gas phase distribution plate is additionally arranged below the mass transfer tower plate to form a two-layer tower plate structure, and the distance between the gas phase distribution plate and the mass transfer tower plate is 20-300 mm; the gas phase distribution plate comprises a non-opening area and an opening area, the non-opening area is arranged on one side of the gas phase distribution plate, the opening area is arranged on the gas phase distribution plate, a transverse baffle is arranged on the opening area, a space formed by the gas phase distribution plate and the mass transfer tower plate is divided into a plurality of areas, valve holes with different numbers are uniformly formed in the gas phase distribution plate of each area, the area ratio of the hole area of each area to the area of each area is equal, and a float valve is arranged on part of the valve holes. The invention has the beneficial effects that: the tower plate structure and the design method have simple structure, can effectively eliminate the forming condition of gas phase bias flow, lead the gas phase flow to tend to be uniform, and greatly improve the operation elasticity and the separation efficiency.

Description

Design method of tower plate structure for eliminating gas phase bias flow
Technical Field
The invention relates to a tower plate structure for eliminating gas phase bias flow and a design method thereof, belonging to the technical field of chemical vapor-liquid mass transfer separation equipment.
Background
Currently, despite the advent of a variety of novel separation techniques, rectification remains the separation technique most used industrially. The most widely used of these is the rectification operation carried out in a tray column. When the liquid phase flows on the tower plate, the liquid level difference is formed on the liquid layer on the tower plate due to the influence of friction resistance, so that the liquid phase on the tower plate is unevenly distributed, and further, gas phase bias flow is formed on the tower plate, particularly on a large-scale plate tower. Once the gas phase bias flow occurs, a large amount of gas phase flows out from the outlet of the tower plate to cause a large amount of entrainment; secondly, no or only a small amount of the gas phase passes through the tray inlet, resulting in a slop at the tray inlet. The abnormal hydromechanics phenomenon not only can obviously reduce the efficiency of the tower plate, but also can induce the tower plate to flood and influence the normal operation of the tower. At present, some technologies such as multi-overflow tower plates, multi-downcomer tower plates and guiding tower plate technologies can regulate and control gas phase bias flow, but the technologies still have the defects that: the multi-overflow tower plate technology has the defects of complex design, particularly along with the increase of overflow number, long installation time and the like; the multi-downcomer tower plate has the defects of low efficiency and the like; the guide-type tray technique cannot cope with cases when the rectification column is in high liquid/vapor ratio conditions or in low-limit operation.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a tower plate structure for eliminating gas phase bias flow and a design method thereof, the structure is simple, the forming condition of the gas phase bias flow can be effectively eliminated, the gas phase flow tends to be uniform, and the operation elasticity and the separation efficiency are greatly improved.
In order to achieve the above object, the present invention adopts the following technical solutions:
a column plate structure for eliminating gas phase bias flow comprises a mass transfer column plate, wherein a gas phase distribution plate is additionally arranged below the mass transfer column plate to form a two-layer column plate structure, and the distance between the gas phase distribution plate and the mass transfer column plate is 20-300 mm; the gas phase distribution plate comprises a non-perforated area and a perforated area except the non-perforated area, the gas phase distribution plate of the perforated area is provided with a transverse baffle plate which divides a space formed by the gas phase distribution plate and the mass transfer tower plate into a plurality of areas, and the transverse direction is perpendicular to the flow direction of the liquid phase; valve holes with different numbers are uniformly arranged on the gas phase distribution plate of each zone, but the area ratio of the holes of each zone to the area of each zone is equal; and a part of the valve holes are provided with floating valves.
In the tower plate structure for eliminating gas phase bias flow, the distance between 2 adjacent baffles is 200-800 mm.
In the tower plate structure for eliminating the bias flow of the gas phase, the optimal distance between 2 adjacent baffles is 400 mm.
According to the tower plate structure for eliminating gas phase bias flow, the opening rate of the valve hole in the gas phase distribution plate is 0.8 to 2.0 times that of the mass transfer tower plate.
According to the tower plate structure for eliminating gas phase bias flow, the opening rate of the valve hole in the gas phase distribution plate is 1.4 times that of the mass transfer tower plate.
In the tower plate structure for eliminating gas phase bias flow, the float valve is a light float valve, preferably a disc-shaped float valve or a strip-shaped float valve.
The above-mentioned tower plate structure for eliminating bias flow of gas phase is characterized by that the mass transfer tower plate is preferably sieve plate or floating valve tower plate or bubble cap.
According to the tower plate structure for eliminating gas phase bias flow, the valve holes are arranged according to an isosceles triangle or an equilateral triangle, and the hole pitch is 60-120 mm; the floating valves are uniformly distributed in each area and are arranged outwards from the middle of each area.
A design method of a tower plate structure for eliminating gas phase bias flow utilizes any one of the tower plate structures, regulates and controls a gas phase flow resistance coefficient of each area by regulating the quantity proportion of a floating valve and a valve hole in each area, further regulates and controls the gas velocity of a liquid layer on a mass transfer tower plate, and eliminates the influence caused by liquid level drop, so that the gas phase of the whole mass transfer tower plate is uniformly distributed, the proportion of a specific valve hole and the floating valve is given by the following formula (14), and the specific design method is as follows:
liquid level gradient on the mass transfer column plate:
Figure GDA0002616737640000031
in the formula (1), Δ h is a liquid level difference; l is the length of a flow channel and is a design parameter of a mass transfer tower plate structure; g is the gravity acceleration equal to 9.81m/s2；uLIs the liquid phase flow velocity on the mass transfer column plate; rhIs the flowing hydraulic radius of the liquid-phase foam layer; f is the coefficient of friction resistance;
wherein the flow velocity u of the liquid phaseLCan be calculated by the following formula:
Figure GDA0002616737640000032
in the formula (2), QlThe liquid phase volume flow is the designed value; h isclThe average supernatant layer height of the mass transfer tower plate; b is the mean flow path width;
average clear layer height hclThe calculation formula of (A) is as follows:
hcl＝hw+how(3)
in the formula (3), hwThe weir height is a design parameter of a mass transfer tower plate; h isowThe height of the liquid layer on the weir can be calculated by the following formula:
Figure GDA0002616737640000033
in the formula (4), LwThe weir length of the mass transfer tower plate is a design parameter of the tower plate structure;
the mean flow path width b can be calculated by:
Figure GDA0002616737640000034
in the formula (5), D is the tower diameter and is a tower plate structure design parameter;
Rhcan be calculated by
Figure GDA0002616737640000041
In the formula (6), hfThe height of the liquid-phase foam layer on the mass transfer column plate can be calculated by the following formula:
hf＝2.5hcl(7)
f can be calculated by:
Figure GDA0002616737640000042
Rehcan be calculated by:
Figure GDA0002616737640000043
in the formula (9), ρLIs the liquid density, is a design parameter; mu.sLThe liquid phase viscosity is a design parameter value;
calculating the liquid level fall delta h on the mass transfer tower plate according to the formulas (1) and (9);
the space between the mass transfer tower plate and the gas phase distribution plate is divided into n parts at equal intervals, the average liquid level drop of two adjacent areas is delta h/n, the relation between the apparent resistance coefficients of the two adjacent areas can be obtained by utilizing pressure balance,
Figure GDA0002616737640000044
in the formula (10), u0The apparent pore velocity of the gas phase on the gas phase distribution plate; delta xi is the difference of the apparent resistance coefficients of gas phase flow in two adjacent areas;
the area near the liquid phase inlet is defined as 1 area, which is sequentially 2 areas, 3 areas, the resistance coefficient of each area is xi1，ξ2、ξ3、、、、，ξn(ii) a Meanwhile, for the convenience of design calculation, if all the 1-zone is set as valve holes and the apparent resistance coefficient is 2.5, the apparent resistance coefficient of the 2-zone is obtained as follows:
Figure GDA0002616737640000045
further obtaining the resistance coefficient zeta of any m areamComprises the following steps:
Figure GDA0002616737640000051
calculating the drag coefficient Zeta of any m area on the distribution plate from the formulas (11) and (12)mThen the apparent pore flow coefficient of the mth zone is:
Figure GDA0002616737640000052
in the formula (13), Cdm(ii) expressing the pore flow coefficient for the mth zone;
when the valve hole is a round hole with the diameter of 39mm and the hole flow coefficient of 0.632, the number fraction of the float valves arranged on the m zone is as follows:
Figure GDA0002616737640000053
in the formula (14), CdfThe hole flow coefficient of the float valve on the distribution plate is the characteristic parameter of the float valve;
Figure GDA0002616737640000054
installing the number fraction of the float valves for the mth zone;
wherein the apparent pore velocity u of the gas phase on the gas phase distribution plate0Can be calculated by the following formula:
Figure GDA0002616737640000055
in the formula (15), VsThe gas phase volume flow is a design parameter value; k is the proportion coefficient of the aperture ratio of the gas phase distribution plate, is between 0.8 and 2.0, and is usually 1.4; eta0The opening rate of the mass transfer column plate is a design parameter of the mass transfer column plate structure; a. thebThe area of the bubbling area of the mass transfer tower plate is a design parameter of the tower structure.
The invention achieves the following beneficial effects:
(1) the invention constructs a double-effect column plate, namely, a gas phase distribution plate is additionally arranged below a mass transfer column plate to form two layers of column plates, and a baffle plate is arranged between the mass transfer column plate and the gas phase distribution plate;
(2) because the liquid phase flow is under the action of frictional resistance, a liquid level drop is formed on the mass transfer tower plate, and further, the bubbles on the mass transfer tower plate are not uniform; the invention is provided with a valve hole on a gas phase distribution plate, and a float valve is arranged on part of the valve hole; firstly, dividing the gas distribution plate into a plurality of areas by using baffles on the gas distribution plate; secondly, the gas phase flow resistance coefficient of each area is regulated and controlled by regulating the quantity proportion of the float valve and the valve hole in each area, and then the gas velocity of the liquid layer entering the mass transfer column plate is regulated and controlled to eliminate the influence caused by the liquid level drop, so that the gas phase of the whole mass transfer column plate is uniformly distributed, thereby increasing the mass transfer efficiency of the mass transfer column plate and improving the processing capacity of the column plate.
Drawings
FIG. 1 is a schematic top view of the mass transfer tray 1 of the present invention with the tray removed;
fig. 2 is a schematic front view of the present invention.
The meaning of the reference symbols in the figures:
1. mass transfer tower plate, 2, gas phase distribution plate, 3, baffle, 4, valve hole, 5, float valve, 6, non-opening area, 7 and parting line.
Detailed Description
The invention is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.
In view of eliminating the influence of gas phase bias flow on the operation elasticity and the separation efficiency of the floating valve rectifying tower, the tower plate structure and the design method adopt a brand new method of combining the valve hole 4 and the floating valve 5 and develop a novel gas phase distribution plate 2 so as to eliminate the gas phase bias flow on the traditional mass transfer tower plate 1.
As shown in figures 1 and 2, the tower plate structure of the invention comprises a mass transfer tower plate 1, a gas phase distribution plate 2 is additionally arranged below the mass transfer tower plate 1 to form a two-layer tower plate structure, and the distance between the gas phase distribution plate 2 and the mass transfer tower plate 1 is 20 mm-300 mm; the gas phase distribution plate 2 includes a non-perforated region 6 provided on one side and a perforated region other than the non-perforated region 6; the non-open area 6 and the open area are divided by a virtual dividing line 7, and the non-open area 6 is arranged for sealing the lower part of the mass transfer tower plate 1; a transverse baffle 3 is arranged on the gas phase distribution plate 2 of the opening area to divide the space formed by the gas phase distribution plate 2 and the mass transfer tower plate 1 into a plurality of areas, and the transverse direction is perpendicular to the liquid phase flow direction; the gas phase distribution plate 2 of each area is uniformly provided with valve holes 4 with different numbers, but the area ratio of the holes of each area to the area of each area is equal; the partial valve hole 4 is provided with a float valve 5.
Further, the distance between 2 adjacent baffles 3 is 200 mm-800 mm; preferably, the optimum spacing between 2 adjacent baffles 3 is 400 mm.
Furthermore, the aperture ratio of the valve hole 4 on the gas phase distribution plate 2 is 0.8 to 2.0 times that of the mass transfer column plate 1; preferably, the opening rate of the valve holes 4 on the gas phase distribution plate 2 is 1.4 times of the opening rate of the mass transfer tray 1.
Preferably, the float valve 5 is a light float valve 5, preferably a disc-shaped float valve 5 or a strip-shaped float valve 5.
Preferably, the mass transfer trays 1 are preferably sieve trays or valve 5 trays or bubble caps.
Furthermore, the valve holes 4 are arranged according to an isosceles triangle or an equilateral triangle, and the hole pitch is 60 mm-120 mm; the float valves 5 are uniformly distributed in each zone and are arranged outwards from the middle of each zone. .
According to the tower plate structure design method, the baffle 3 is arranged on the gas phase distribution plate 2, and once gas phase bias flow occurs on the mass transfer tower plate 1, the baffle 3 has the effect of preventing the gas phase at the inlet end from migrating to the outlet end. Considering the liquid level drop on the tower plate, the bubbles on the whole tower plate are not uniform, and the valve holes 4 and the floating valves 5 with different proportions are arranged in the area divided by the baffle 3 to regulate and control the resistance coefficient of gas phase passing in the area. The specific ratio of the valve hole 4 to the float valve 5 is given by the following formula (14), and the specific design method is as follows:
liquid level gradient on the mass transfer tower plate 1:
Figure GDA0002616737640000071
in the formula (1), Δ h is a liquid level difference; l is the length of a flow channel and is a structural design parameter of the mass transfer tower plate 1; g is the gravity acceleration equal to 9.81m/s2；uLIs the liquid phase flow velocity on the mass transfer column plate; rhIs the flowing hydraulic radius of the liquid-phase foam layer; f is the coefficient of friction resistance;
wherein the flow velocity u of the liquid phaseLCan be calculated by the following formula:
Figure GDA0002616737640000081
in the formula (2), QlThe liquid phase volume flow is the designed value; h isclThe average supernatant layer height of the mass transfer tower plate; b is the mean flow path width;
average clear layer height hclThe calculation formula of (A) is as follows:
hcl＝hw+how(3)
in the formula (3), hwThe design parameter is the weir height and is the design parameter of the mass transfer tower plate 1; h isowThe height of the liquid layer on the weir can be calculated by the following formula:
Figure GDA0002616737640000082
in the formula (4), LwThe length of a weir 1 of the mass transfer tower plate is a tower plate structure design parameter;
the mean flow path width b can be calculated by:
Figure GDA0002616737640000083
in the formula (5), D is the tower diameter and is a tower plate structure design parameter;
Rhcan be calculated by
Figure GDA0002616737640000084
In the formula (6), hfThe height of the liquid-phase foam layer on the mass transfer tower plate 1 can be calculated by the following formula:
hf＝2.5hcl(7)
f can be calculated by:
Figure GDA0002616737640000085
Rehcan be calculated by:
Figure GDA0002616737640000091
in the formula (9), ρLIs the liquid density, is a design parameter; mu.sLThe liquid phase viscosity is a design parameter value;
calculating the liquid level fall delta h on the mass transfer tower plate 1 according to the formula (1) and the formula (9);
the space between the mass transfer tower plate 1 and the gas phase distribution plate 2 is divided into n parts at equal intervals, the average liquid level drop of two adjacent areas is delta h/n, the relation between the apparent resistance coefficients of the two adjacent areas can be obtained by utilizing pressure balance,
Figure GDA0002616737640000092
in the formula (10), u0The apparent pore velocity of the gas phase on the gas phase distribution plate 2; delta xi is the difference of the apparent resistance coefficients of gas phase flow in two adjacent areas;
the area near the liquid phase inlet is defined as 1 area, which is sequentially 2 areas, 3 areas, the resistance coefficient of each area is xi1，ξ2、ξ3、、、、，ξn(ii) a Meanwhile, for the convenience of design calculation, if all the 1-zone is set as the valve hole 4 and the apparent resistance coefficient is 2.5, the apparent resistance coefficient of the 2-zone is obtained as follows:
Figure GDA0002616737640000093
further obtaining the resistance coefficient zeta of any m areamComprises the following steps:
Figure GDA0002616737640000094
calculating the drag coefficient Zeta of any m area on the distribution plate from the formulas (11) and (12)mApparent pore of the m-th zoneThe flow coefficient is:
Figure GDA0002616737640000095
in the formula (13), Cdm(ii) expressing the pore flow coefficient for the mth zone;
when the valve hole 4 is a circular hole with a diameter of 39mm and a hole flow coefficient of 0.632, the number fraction of the float valves 5 installed on the m-th area is as follows:
Figure GDA0002616737640000101
in the formula (14), CdfThe hole flow coefficient of the float valve 5 on the distribution plate is the characteristic parameter of the float valve 5;
Figure GDA0002616737640000102
installing the number fraction of the float valves 5 for the mth zone;
wherein the apparent pore velocity u of the gas phase on the gas phase distribution plate 20Can be calculated by the following formula:
Figure GDA0002616737640000103
in the formula (15), VsThe gas phase volume flow is a design parameter value; k is the proportion coefficient of the aperture ratio of the gas phase distribution plate 2, is between 0.8 and 2.0, and is usually 1.4; eta0The opening rate of the mass transfer tower plate 1 is a structural design parameter of the mass transfer tower plate 1; a. thebThe area of the bubbling area of the mass transfer tower plate 1 is the design parameter of the tower structure.
Example 1:
the gas phase mass flow rate is 15000kg/hr, and the gas phase density is 2.5kg/m3The mass flow rate of the liquid phase is 40000kg/hr, and the density of the liquid phase is 880kg/m3The surface tension was 10N/m, and the viscosity was 1 mPas. The type of the mass transfer column plate is selected as a sieve plate column, and the structural parameters of the obtained plate type are shown in table 1 through preliminary design:
TABLE 1 design parameters of mass transfer column plate structure
Figure GDA0002616737640000104
The parameters obtained by calculation according to the formulas (1) to (9) are shown in Table 2:
TABLE 2 calculation results of liquid level gradient related parameters of mass transfer tower plate
Figure GDA0002616737640000105
The gas phase distribution plate was divided into five zones, each zone had a length of 200mm, and the gas phase distribution plate had an aperture ratio proportionality coefficient of 1.4 (aperture ratio of 17.85%) and the apparent hole velocity of the gas phase distribution plate was 8.98m/s as calculated by the formula (15). When the apparent drag coefficient of zone 1 was set to 2.5, the apparent drag coefficient and apparent pore flow coefficient of zones 2, 3 and 4 were calculated by equations (12) and (13), respectively, as shown in Table 3.
TABLE 3 calculation results of resistance coefficient and apparent pore flow coefficient for each zone
Figure GDA0002616737640000111
The gas phase flow resistance coefficient of the float valve was set to 5.32, and the orifice flow coefficient thereof was 0.434. The number fraction of float valves for each zone was calculated by taking the calculation results in table 3 into equation (14), see table 4.
TABLE 4 number fraction of float valve for each zone design results
Figure GDA0002616737640000112
Example 2:
the gas phase mass flow is 60000kg/hr, and the gas phase density is 2.5kg/m3The mass flow rate of the liquid phase is 70000kg/hr, and the density of the liquid phase is 880kg/m3The surface tension was 10N/m, and the viscosity was 1 mPas. The type of the mass transfer column plate is selected as a sieve plate column, and the structural parameters of the obtained plate type are shown in a table 5 through preliminary design:
TABLE 5 design parameters of mass transfer column plate structure
Figure GDA0002616737640000113
The parameters obtained by calculation according to the formulas (1) to (9) are shown in Table 6:
TABLE 6 calculation results of liquid level gradient related parameters of mass transfer tower plate
Figure GDA0002616737640000114
The gas phase distribution plate was divided into four zones, each zone had a length of 400mm, and the gas phase distribution plate had an aperture ratio proportionality coefficient of 1.4 (aperture ratio of 20.31%) and the apparent hole velocity of the gas phase distribution plate calculated by the formula (15) was 8.55 m/s. When the apparent drag coefficient of zone 1 was set to 2.5, the apparent drag coefficient and apparent pore flow coefficient of zones 2, 3 and 4 were calculated by equations (12) and (13), respectively, as shown in Table 7.
TABLE 7 calculation results of resistance coefficient and apparent pore flow coefficient for each zone
Figure GDA0002616737640000121
The steam-gas flow resistance coefficient of the float valve was set to 5.32, and the orifice flow coefficient thereof was 0.434. The number fraction of float valves for each zone was calculated by taking the calculation results in table 3 into equation (14), see table 8.
TABLE 8 number fraction of float valves for each zone design results
Figure GDA0002616737640000122
Example 3:
the gas phase mass flow is 60000kg/hr, and the gas phase density is 2.5kg/m3The mass flow rate of the liquid phase is 70000kg/hr, and the density of the liquid phase is 880kg/m3The surface tension was 10N/m, and the viscosity was 1 mPas. The type of the mass transfer column plate is selected as a sieve plate column, and the structural parameters of the plate type are obtained through preliminary design and are shown in a table 9:
TABLE 9 design parameters of mass transfer tower plate structure
Figure GDA0002616737640000123
The parameters are calculated by the formulas (1) to (9) and are shown in the table 10:
TABLE 10 calculation results of liquid level gradient related parameters of mass transfer tower plate
Figure GDA0002616737640000124
The gas phase distribution plate was divided into 2 zones, each zone had a length of 800mm, and the gas phase distribution plate had an aperture ratio proportionality coefficient of 1.4 (aperture ratio of 20.31%) and the apparent hole velocity of the gas phase distribution plate calculated by the formula (15) was 8.55 m/s. When the apparent drag coefficient of zone 1 was set to 2.5, the apparent drag coefficient and apparent pore flow coefficient of zones 2, 3 and 4 were calculated by equations (12) and (13), respectively, as shown in Table 11.
TABLE 11 results of calculation of resistance coefficient and apparent pore flow coefficient for each zone
Figure GDA0002616737640000131
The gas phase flow resistance coefficient of the float valve was set to 5.32, and the orifice flow coefficient thereof was 0.434. The number fraction of float valves for each zone was calculated by taking the calculation results in table 3 into equation (14), see table 12.
TABLE 12 number fraction of float valve for each zone design results
Figure GDA0002616737640000132
The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.

Claims (9)

1. A design method of a tower plate structure for eliminating gas phase bias flow utilizes a tower plate structure for eliminating gas phase bias flow, the tower plate structure comprises a mass transfer tower plate, a gas phase distribution plate is additionally arranged below the mass transfer tower plate to form a two-layer tower plate structure, and the distance between the gas phase distribution plate and the mass transfer tower plate is 20-300 mm; the gas phase distribution plate comprises a non-perforated area and a perforated area except the non-perforated area, the gas phase distribution plate of the perforated area is provided with a transverse baffle plate which divides a space formed by the gas phase distribution plate and the mass transfer tower plate into a plurality of areas, and the transverse direction is perpendicular to the flow direction of the liquid phase; valve holes with different numbers are uniformly arranged on the gas phase distribution plate of each zone, but the area ratio of the holes of each zone to the area of each zone is equal; a part of the valve hole is provided with a floating valve; the method is characterized in that:
the gas phase flow resistance coefficient of each area is regulated and controlled by adjusting the quantity proportion of the floating valve and the valve hole in each area, and then the gas velocity of a liquid layer entering a mass transfer column plate is regulated and controlled to eliminate the influence caused by liquid level drop, so that the gas phase of the whole mass transfer column plate is uniformly distributed, the proportion of the specific valve hole and the floating valve is given by the following formula (14), and the specific design method is as follows:
liquid level gradient on the mass transfer column plate:
Figure FDA0002652254320000011
in the formula (1), Δ h is a liquid level difference; l is the length of a flow channel and is a design parameter of a mass transfer tower plate structure; g is the gravity acceleration equal to 9.81m/s2；uLIs the liquid phase flow velocity on the mass transfer column plate; rhIs the flowing hydraulic radius of the liquid-phase foam layer; f is the coefficient of friction resistance;
wherein the flow velocity u of the liquid phaseLCan be calculated by the following formula:
Figure FDA0002652254320000012
in the formula (2), QlThe liquid phase volume flow is the designed value; h isclThe average supernatant layer height of the mass transfer tower plate; b is the mean flow path width;
average clear layer height hclThe calculation formula of (A) is as follows:
hcl＝hw+how(3)
in the formula (3), hwThe weir height is a design parameter of a mass transfer tower plate; h isowThe height of the liquid layer on the weir can be calculated by the following formula:
Figure FDA0002652254320000021
in the formula (4), LwThe weir length of the mass transfer tower plate is a design parameter of the tower plate structure;
the mean flow path width b can be calculated by:
Figure FDA0002652254320000022
in the formula (5), D is the tower diameter and is a tower plate structure design parameter;
Rhcan be calculated by
Figure FDA0002652254320000023
In the formula (6), hfThe height of the liquid-phase foam layer on the mass transfer column plate can be calculated by the following formula:
hf＝2.5hcl(7)
f can be calculated by:
Figure FDA0002652254320000024
Rehcan be calculated by:
Figure FDA0002652254320000025
in the formula (9), ρLIs the liquid density, is a design parameter; mu.sLThe liquid phase viscosity is a design parameter value;
calculating the liquid level fall delta h on the mass transfer tower plate according to the formulas (1) and (9);
the space between the mass transfer tower plate and the gas phase distribution plate is divided into n parts at equal intervals, the average liquid level drop of two adjacent areas is delta h/n, the relation between the apparent resistance coefficients of the two adjacent areas can be obtained by utilizing pressure balance,
Figure FDA0002652254320000031
in the formula (10), u0The apparent pore velocity of the gas phase on the gas phase distribution plate; delta xi is the difference of the apparent resistance coefficients of gas phase flow in two adjacent areas;
the area near the liquid phase inlet is defined as 1 area, 2 area, 3 area … …, n area, and the resistance coefficient of each area is xi1，ξ2、ξ3……，ξn(ii) a Meanwhile, for the convenience of design calculation, if all the 1-zone is set as valve holes and the apparent resistance coefficient is 2.5, the apparent resistance coefficient of the 2-zone is obtained as follows:
Figure FDA0002652254320000032
further obtaining the resistance coefficient zeta of any m areamComprises the following steps:
Figure FDA0002652254320000033
calculating the drag coefficient Zeta of any m area on the distribution plate from the formulas (11) and (12)mThen the apparent pore flow coefficient of the mth zone is:
Figure FDA0002652254320000034
in the formula (13), Cdm(ii) expressing the pore flow coefficient for the mth zone;
when the valve hole is a round hole with the diameter of 39mm and the hole flow coefficient of 0.632, the number fraction of the float valves arranged on the m zone is as follows:
Figure FDA0002652254320000035
in the formula (14), CdfThe hole flow coefficient of the float valve on the distribution plate is the characteristic parameter of the float valve;
Figure FDA0002652254320000036
installing the number fraction of the float valves for the mth zone;
wherein the apparent pore velocity u of the gas phase on the gas phase distribution plate0Can be calculated by the following formula:
Figure FDA0002652254320000041
in the formula (15), VsThe gas phase volume flow is a design parameter value; k is the proportion coefficient of the aperture ratio of the gas phase distribution plate, is between 0.8 and 2.0, and is usually 1.4; eta0The opening rate of the mass transfer column plate is a design parameter of the mass transfer column plate structure; a. thebThe area of the bubbling area of the mass transfer tower plate is a design parameter of the tower structure.
2. The design method of a tower plate structure for eliminating bias flow of gas phase as claimed in claim 1, wherein: the distance between 2 adjacent baffles is 200 mm-800 mm.
3. The design method of a tower plate structure for eliminating bias flow of gas phase as claimed in claim 2, wherein: the optimal spacing between 2 adjacent baffles is 400 mm.
4. The design method of a tower plate structure for eliminating bias flow of gas phase as claimed in claim 1, wherein: the opening rate of the valve hole on the gas phase distribution plate is 0.8 to 2.0 times of the opening rate of the mass transfer column plate.
5. The design method of a tower plate structure for eliminating bias flow of gas phase as claimed in claim 4, wherein: the aperture ratio of the valve hole on the gas phase distribution plate is 1.4 times of the aperture ratio of the mass transfer column plate.
6. The design method of a tower plate structure for eliminating bias flow of gas phase as claimed in claim 1, wherein: the float valve is a light float valve.
7. The design method of a tower plate structure for eliminating bias flow of gas phase as claimed in claim 1, wherein: the mass transfer tower plate is a sieve plate or a floating valve tower plate or a bubble cap.
8. The design method of a tower plate structure for eliminating bias flow of gas phase as claimed in claim 1, wherein: the valve holes are arranged according to an isosceles triangle or an equilateral triangle, and the hole pitch is 60-120 mm; the floating valves are uniformly distributed in each area and are arranged outwards from the middle of each area.
9. The design method of a tower plate structure for eliminating bias flow of gas phase as claimed in claim 6, wherein: the light float valve is a disc-shaped float valve or a strip-shaped float valve.
CN201811234763.7A 2018-10-23 2018-10-23 Design method of tower plate structure for eliminating gas phase bias flow Active CN109200614B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201811234763.7A CN109200614B (en) 2018-10-23 2018-10-23 Design method of tower plate structure for eliminating gas phase bias flow

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201811234763.7A CN109200614B (en) 2018-10-23 2018-10-23 Design method of tower plate structure for eliminating gas phase bias flow

Publications (2)

Publication Number Publication Date
CN109200614A CN109200614A (en) 2019-01-15
CN109200614B true CN109200614B (en) 2020-10-23

Family

ID=64981300

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201811234763.7A Active CN109200614B (en) 2018-10-23 2018-10-23 Design method of tower plate structure for eliminating gas phase bias flow

Country Status (1)

Country Link
CN (1) CN109200614B (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110433518A (en) * 2019-07-31 2019-11-12 常州大学 A kind of pulsation float valve mass transfer component
CN111914363A (en) * 2020-07-28 2020-11-10 北京化工大学 Quantitative anti-blocking design method of guide sieve plate
CN115121139B (en) * 2022-03-29 2023-08-25 上海良薇机电工程有限公司 Liquid source bubbler

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1294936A (en) * 2000-08-29 2001-05-16 罗固事 Convective column plate
CN1298751A (en) * 2000-04-04 2001-06-13 中国石油化工集团公司 Tower plate for gas-liquid mass transfer
CN2915211Y (en) * 2006-06-20 2007-06-27 山东美陵化工设备股份有限公司 Highly efficient combined column tray of coking fractional column
CN101402000A (en) * 2008-10-27 2009-04-08 杭州中泰过程设备有限公司 Plate-fin stuffing rectification column
WO2018122750A1 (en) * 2016-12-28 2018-07-05 Koch-Glitsch, Lp Contact tray having picketed liquid flow barriers and method involving same

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102012204436A1 (en) * 2012-03-20 2012-10-04 Basf Se Thermal separation between at least a gas ascending- and a liquid containing at least a (meth)acrylic-monomer descending respectively in separating column, accomplished in a separation effective installation containing separating columns

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1298751A (en) * 2000-04-04 2001-06-13 中国石油化工集团公司 Tower plate for gas-liquid mass transfer
CN1294936A (en) * 2000-08-29 2001-05-16 罗固事 Convective column plate
CN2915211Y (en) * 2006-06-20 2007-06-27 山东美陵化工设备股份有限公司 Highly efficient combined column tray of coking fractional column
CN101402000A (en) * 2008-10-27 2009-04-08 杭州中泰过程设备有限公司 Plate-fin stuffing rectification column
WO2018122750A1 (en) * 2016-12-28 2018-07-05 Koch-Glitsch, Lp Contact tray having picketed liquid flow barriers and method involving same

Also Published As

Publication number Publication date
CN109200614A (en) 2019-01-15

Similar Documents

Publication Publication Date Title
CN109200614B (en) Design method of tower plate structure for eliminating gas phase bias flow
EP0599454A1 (en) A gas-liquid contacting device
US2973189A (en) Fractionating columns
CN102961888B (en) Flow-separation back-mixing-free spraying tower disc
KR101386106B1 (en) Gas-liquid contact apparatus
MARUYAMA et al. The flow transition in a bubble column
US9630154B2 (en) Apparatus and method for contacting a gas and a liquid
EP0319558A1 (en) Vapor-liquid contact device and method
US8800971B2 (en) Gas-liquid contact column and method using a combination of trays and packings
CN103239883B (en) To wait method of time of staying method design multi-overflow column plate
US10434438B2 (en) Fluid contact tray particularly for the use in an offshore fractionation column
WO2023045528A1 (en) Column plate having multiple bubbling zones, and corresponding plate column
US20080264489A1 (en) Method and a Device for Handling a Liquid
Chuang et al. Tray columns: design
CN203648122U (en) Gas-liquid mass transfer improved structure of tower plate of float valve tower
US9346010B2 (en) Shielding in a separation column
US3445094A (en) Dynamically balanced multi-path liquid-gas contacting
WO2021080436A1 (en) Separator
CN205613089U (en) Column plate subassembly and have its gas -liquid separation tower
Rahimi et al. A computational fluid dynamics and an experimental approach to the effects of push valves on sieve trays
JP2013066841A (en) Vapor flow control apparatus by divided bundle in multiple-effect fresh water generator
CN107899535B (en) Gas jet flow distributed tower plate without amplification effect and design method thereof
EP0054281A1 (en) Sectioned bubble tray distillation over a wide range of feed composition and bubble tray loading
CN110193213A (en) A kind of anti-clogging tower tray
CN103418154A (en) Tower plate gas-liquid mass transfer improvement structure of float valve tower

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant