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Home >> Industry Knowledge >> Nitrogen Generator (Nitrogen Equipment) plate column - I
Yun-level tower is a plate-type gas-liquid contact and mass transfer equipment, gas tower plate through the right, across the board tower liquid layer mass transfer
Heat transfer. Configuration space plate tower tower packing tower faster than the high production capacity and therefore large, but a larger pressure drop. Larger diameter towers, mining
With plate-type towers Liu light weight, low cost. Maintenance clean-up easy. Enlarge the diameter of tray column, the tray efficiency of relatively stable. Plate
Tower is a tower plate of a wide range of tower equipment.
Sieve tray column can be divided into rhyme have downcomer and downcomer tube-free (to wear streaming tray) two broad categories. There are tubular downcomer tray.
Between the tray for the liquid through the downcomer, the liquid on each plate tower height high weir overflow weir can be adjusted a certain
Flexibility in the scope of the operation, higher efficiency.
Wear plate flow, gas-liquid two-phase at the same time by the Tower board
By a number of holes (such as the inverted sieve) through the reverse please touch pond. Knot
The saved configuration downcomer to deal with power boats, drop a small, but
Tray efficiency and operational flexibility are subject to - will be restricted.
For air distillation tower before the sieve plate are liquid shallot are open pipe
Sieve plate tower. .
A
, Fu Pei tectonic plate
Sieve plate tower by the tower and plate composition, Figure 5-13
The structure shown by the sieve plate, overflow weir, downcomer
And so on.
1. Sieve
, To
Head of a 13 plate column 5 indicate intercalated
l, overflow weir possession 2. Import weir 3. Plate
Sieve diameter d is generally 0.8 ~ 1.3 mm,
Range.
Opening rate is
~ 0 ~ 0.907
A i
Where. 11 sieve size
.
- - Opening area
Triangular in shape with Sieve. Center Spacing t sieve in the 1.2 ~ 4 mm
Openings rate is generally 0.05 ≤ ≤ O. 15, namely t / do =
2.5 ~ 4 t / <2, plate is not stable operation. Opening rate
Small, hole-speed, and tray pressure drop caused by fog easily execute large and liquid entrainment
Pan, Yi each other in the disturbance caused by air currents, small aperture and small opening rate
Flexible operation of the plate. Openings rate is high, speed small hole, easy production
Health leakage, entrainment of small, narrow operating range.
Tower board, the next paragraph larger load changes, the above rhyme Sieve
Diameter and hole spacing can be different, so that the whole tower has a good stable operation
Will be offering.
2. Liquid flow pattern
Waterloo won
Weeping Circumfluent cut plate-type tray
Figure 5 - 14 circulation and convection-style tray
Trays are commonly used in fluid flow and convective flow of the ring are shown in Figure 5-14. Annular flow tray
Both inside and outside diameter of the tube than in the 2.4 ~ 3 Fan circle.
According to the liquid flow channel can be divided into single-flow type, double type, the four flow patterns and so on, as shown in Figure 5-15. Liquid by liquid flow by the number of negative
Select the size of a single load flow model for small-scale air separation equipment, tower b15oo mm in diameter below Shuangliu separate type for the medium-air
Preparation, Tower Drive in the t, 2ooomm about cutting the four streams for large-scale air separation equipment, tower above the track at ~ 30001TtlTt.
0 @ ① ① @ ④ a @
Single-flow pattern
(Of water)
Four dual-flow water-based single-flow-type four-flow pattern Shuangliu
(Convection) (convection) (Circulation) (Circulation) (Circulation)
5-15 Luoyu solid plate flow pattern (arrows hit Sui body for the flow)
3. Plate spacing
Asked the size of plate and liquid from the pan and fog volume the size of attachments-soo. Plate spacing, and of production capacity, tray efficiency, Cao
Flexibility, installation maintenance and other benefits, but it will increase the tower height, increased metal consumption, high cost.
Tray spacing of 70 ~ 200 mm in the framework of
4. A run-off devices
Overflow device includes downcomer, and liquid overflow weir plate and other components.
Downcomer (overflow pipe) the form of straight and oblique overflow overflow, there are flat plate by the liquid and the concave shape. The main air distillation column an overflow pipe
There are three types, such as the circle shown in 5-16.
I also can weir liquid evenly into the tray.
Trays are equipped with overflow weir (weir exports), which Trays
There are some clear liquid height and liquid evenly on the board in the tower
Distribution. Overflow weir height of 5 ~ lSmm Fan in the country, for large
Type tower, due to the overflow tower on the board too much strength, high flow weir on
High, the use of small overflow weir height values.
Affect the length of overflow weir overflow intensity (in the long weir
Flow known as the overflow of the liquid flow strength), Yi-Ying intensity,
Liquid height on the weir overflow weir major also affects the long Trays
Uniform flow distribution. Weir length and the ratio of tower diameter, there must be
For: single-flow type, weir length of the tower diameter 0.6 ~ O. 8-fold, Shuangliu
Type, weir length of Tower Drive 0.5 ~ 0.7-fold. Different weir long bow
Shaped downcomer downcomer area and width as shown in Figure 5-l7.
Fluid in the overflow plate and pipe ramp there is leakage at the bottom of the tear open
Hole in order to rule out the fluid when parking. Figure 5-17 become not downcomer of the nomogram
Plate fixation of the structure and materials related to love. Copper plate with the two upper and lower clamping ring fixed in the cylinder on
Rolled out between the two slot, copper ring can be pressed into oval-shaped control, fixed-tin solder. Upper and lower aluminum tray are
Kok fixed, there is a simplified rolling groove, with isolated heavy atmosphere welding as shown in Figure 5-l8.
The level of sieve plate column degrees of impact on the work, degree requirements for the level of ~ / looo around.
5. Linde sieve
Figure 5-19 sieve for Linde diagram of the structure characterized by:
(1) in the liquid to enter the area, will be raised tray made of the Taiwan oblique-shaped bubble devices, reducing the height of the liquid, the entire tower
The gas distribution plate, full of gas-liquid contact. Ordinary plate surface as a result of higher liquid to enter the Department, which easily give rise to leakage,
Large number of gas exit through the lower surface, causing an increase in fog entrainment to punish, the impact of tray efficiency. Linde sieve plate and the general
UAE
. ) (| Xi-bound
Figure 5-19 sieve Linde
-43
L) l knot braided floor sweep handle tower
Figure 5 - 18 the way the draw tower
Have possession of commonly used twisted tower face off
Yan poor distribution of recorded lazy j
Common plate area of imports slightly
Possession, the district head on blow j
Lin Lu uniform foam plate
Level and steam flow to punish
5 ~ 20 Linde circle plate with ordinary bubble map layer 5-2l mobile sub -
Plate compared the situation of the movement of cloth
Win the state of physical science as shown in Figure 5-2O.
(2) in the tower on the board with a certain number of blind holes oriented style. Hole-oriented direction and liquid flow in the tower on the board
Direction of gas flow through the guide hole to promote, you can reduce the level gap, but also can adjust the height of the bubble
In addition, Linde plate on the plate with the general movement of the bubble layer is different, as shown in Figure 5-2l. Plate on the general flow is
Uneven, Yun tray center to a larger flow rate of liquid flow on both sides of the slow flow of liquid. Trapped in the foam layer tray
The residence time is different, with the result that under the open tray efficiency. Linde plate to maintain uniform liquid residence time, and stop
Leave time from the tower of the uniformity of the impact of too small diameter, the plate and high efficiency.
Linde sieve evenly bubbling liquid layer, surface gradient of small, small pressure drop, processing capacity, and the county have a good mass transfer effects,
Is a good performance of the plate.
Distillation separation plant some room to catch the technical specifications in Table 6-4 Table 5-5 and Table 5-6.
= Have downcomer performance of sieve-plate column
1. Tap plate on the liquid structure
Plate on the structure of the gas concentration is divided into three regional t drum f (! 【Layer, foam layer and spicy entrainment, as shown in Figure 5-22.
Network
Table 5-4 China, the low-pressure air separation
ASU Model l KFS a 3Do l KFS a 850-2 l KDON-iooo/ioo ~ KDON a 1500/1500-1
On the tower 'on the tower
Under parts of the tower tower tower tower under the 'l. Crucible 1. 2 3 under the tower
Plate form of speech 'cry cry Ringspot plate plate plate circulation circulation Hao board
Tap plate, Bu Path (mm) 2B5 198 5 to 400 55D 1loD l1100 lg2D 8O0 l140O 1i mbO f1i00
Tower diameter plate (mrt1) 11 215 170 215 35 0): 50 350 450 I 4SO 450 450
Tower-way to one - a 2.3 2.35 2 56 3 1 d 【3 1 4 2.62 1 78I 3.1
I overflow the number of H (10) L 1 1 1 1 1 l 1 1 1 1 l
Sieve diameter d0 (mm) 0.8 0.8 0. I 0 9 D. g 1 D. 9 1 1 l l 1
Hole center box t (m m) 3 25 3 25 3 25 3. 3 25 3 25 3 25 3.25
A high degree of ring closure starting a (mm) 10 10 10 10
Hang overflow weir height (mm) l5 1; 15 15 15 1 0 1D 10 i0 1 J
Imports of high-jiang (mm) 18 l8 2o 20 40 J 4 u 4D (0 25 l 2
Austin from the tray (mm) 75 7; 80 80 110 I 11. j 90 』90 9 3 00 11 0 l l10
Wooden tower on the t 1 - Po tower above, 2 - expansion of the air gap own import export position Bute Ko Kr, 3 - bottom out on the location of the expansion of air imports.
Table 5-5 Linde AG 10000m. / H, 30000mS / h at the main parameters of distillation equipment
§ l lO000m ~ / h 3O0O0 ¨ m '/ h
On Tap 'on Tap'
Under the tower under the tower site
l l 2 3 4 j 5 l 2 I 3 4 S
385O 3250
4 2
1.1 1.1
3.2 3.2
_
7 i lD. 7 10.7
Tower of Tibetan plate diameter (mm) 1245 Z450 l24SD Z450) 245D 225D 2850 385 0 l38S0
Population overflow (10) 1 2 2 2 4 4) 4
Sieve diameter (mm) 1.1 0 9 0 g 0 9I 1.1 0.9 1.1 0.9 0.9
Hole Center Distance (mm) 3.2I 2.1 2.1 3 2 3.2 3.2 2 85 2. 1 2.1
Opening rate () l0.7I l6.7 l6.7 7. 1O. 7 7.2 13.5 16.7) 16.7
Ke plate distance (mtiTt) l 140 l 20 0 I 200 1BO l 140 180 l3O 180 l 160 120 1GO
Wood tower) 1 - - Des tower above ** sieve-type air-Dan Equipment
2 - - mounted air import export position to share the location of Holland
3 - - Liao together to ring the location of the air space of imports import location
4 - Dan pumping distillate heavy atmosphere thistle population expansion of the location of the location of the air imports
5 on the bottom of a heavy atmosphere over who smoke Xi I: 1 position
Sang bubbling layer is affixed to plate layer of a layer of clear liquid, bubbles floating in its continuing. Foam layer in the layer above the bubble, was bee
Nest-like structure, and its intense disturbance in the liquid bubbles, bubble formation and frequently break down, steam and liquid droplets contact the surface of a large,
Mass transfer and heat transfer is a major occasion. Fog foam layer in the foam layer above the liquid jet into a fog was spread over the gas implicated in the last few
Droplet volume of steam to the upper plate was referred to as entrainment. Entrainment of liquid back-mixing as a result of that component by the oxygen concentration after
The introduction of liquid back to the lower component of the liquid oxygen, and the mass transfer efficiency caused by this restriction in the volume entrainment 0.1 kg
Liquid / l kg of gas below the guarantee to limit the flow of steam.
Different liquid load plate, the foam layer height and air speed V of the relationship between tower as 5-23 ring run by nJ. Know
Oxygen concentration in the liquid fraction of foam the size of the impact of a great height.
KD0N a 320 o/320 0 KFD a'10OO KDoN a 1000 o / looo 0
On the tower tower tower
. F under the tower tower
l 2 3 1 2 I 3 2 3
Sieve plate circulation flow circulation Tanzania tuna plate
110O 1800 1809 '18O0 1500 2500 2304 2050 18O0 3200 3200 l 2850
450 804 800 800 5 0 85 0 850 70 70 12O0 120 f 1O00
2. t5 0. 2 25 2 25 3 2 8d 2 i 2 03 2.56 2.8 2 67J 2 83
2 2 l 2 2 2 2 0
O. 9 1 1 1.1 1 0 g
3.25 3.25 3.25l 3 25 3.25 3 25 3.25 3.25 3 25 3.25 3.25 3.25
6 6 6 『6 '6) 4 5 3 3 3 3
6 I 8 7 1l t 8 l0 5 5 5 5
16 25 19) 21 21 21 l 19 21 ^ 0 4a '' O
9O 13O 1 groan 【10O 90 110 l 11fJ 100 l30 1 30 0 【130
2. Pressure Drop
Tray is the increased resistance of steam through a tray that must be overcome resistance. Plate resistance is composed of three parts, namely, 1000
Plate resistance, resistance and bubbling liquid layer when the surface tension of the liquid to overcome the pressure head.
Sieve tray stem resistance and speed of steam. Fluid resistance with Tower repeated on-board liquid layer and the hydrostatic head of the state of the bubble on the
When the opening rate of a certain plate to increase the speed of air tower. Increase the resistance to plate, as shown in Figure 5-24. Air distillation
The pressure drop in tray for a 200 ~ 350 Pa (20 ~ 35mm H2O).
3. Surface gradient
Granted on the liquid flow in the tower, in order to overcome the flow resistance Trays gradient liquid form. Annular flow for the plate not only
Gradient surface-way measures, but also around the center as a result of fluid flow generated by rotating the radial gradient surface with gradient surface overflow
Intensity increases, but also with the fluid flow path of growth increased with the level of degrees of the tray. The impact of surface gradient
Gas in the tower granted through the uniform, thus affecting the mass transfer efficiency, the design of surface gradient requirement of no more than dry plate resistance 5O.
4. The operation of plate
Plate operation, the liquid cross-flow weirs by the import tray off, fully in contact with the gas from the downcomer into the lower tray
In the downcomer tube should have sufficient time for the separation bubble and the clear liquid into a gas break, if the liquid load increased, the liquid in the downcomer
Speed up the flow rate, residence time should be shortened, when the stop time so that the liquid entrainment Liu bubble separation time was taken to
The lower tray, it will reduce the separation effect, then known as the downcomer overload.
Downcomer ugly for a high level within
B = ^ + ho 10 + +
Where ^. - The height of overflow weir
ho =- - weir height on the flow
- - Import and export of the surface gradient between the weir
k - the gas pressure drop through a plate
^ - Liquid through the downcomer resistance losses
Table 5-6 "V-shape space next to God did not prepare the main parameters of distillation column
H Ⅱ I --
I 1 go 0o '
(1) fine tower wall diameter (13-1m) lg0 0
(2) on the number of overflow tube (10)
(3) plate with the distance (ram) i 00
(4) degree of air tower building (m / s) j
(5) Qiongzhuea center hole diameter x distance (ram)
(6) Sieve speed (m / s)!
(7) weir height on the surface (ram) (
(8) plate on the surface stability and business degrees Ohm)
(1) sperm straight-way tower Po (m m)
(2) the number of overflow (10)
(3) tower plate spacing (mm)
(4) degree of air tower building (m / s)
(5) Sieve heart from the hole diameter × cmm)
(6) Sieve speed (m / s)
(7) weir to the liquid and virtual (m131) I
(8) plate on the surface stability and a high degree of respect (mil1) 1
Large liquid load, h? D, and ^ d are increased in the liquid downcomer on d also increased, and vice versa.
When the gas velocity is low, the tower on the board all of the liquid falling from the sieve, and Tajikistan on the board without liquid layer, increasing gas velocity, a tray I:
Liquid layer at this time began to take shape as the liquid seal "(mid-point of Figure 5-25). Further increasing gas velocity, liquid will soon reach the weir high pressure drop
Has been a corresponding increase (the figure 'B point), this time to achieve the maximum liquid seal. Increased gas and then deep, on the part of the liquid over the overflow weir from the drop
Liquid pipe flow, the other part to the next by a sieve plate leakage, a phenomenon known as the. Leakage. "Leakage of the plate is not uniform
And part of the steam through the sieve, sieve in the other part of leakage, and the location is not fixed, the changes at any time. Leakage
Volume with the increase of gas velocity is reduced, sieve was air blowing increasing the degree of opening, when the gas velocity increased to the full blown Sieve
Opened, the leakage is stopped, the figure 'B is a sieve after blowing open the process of gradually increasing the degree, although this stage of gas
Increasing load, but the gas velocity through the sieve is always the same, so do not drop with the increase of gas velocity increased, reached the figure劐
C points as the leakage point cut at this time of the gas velocity to maintain the liquid can not leak in the tower on the board, gas velocity Xiaoyu leakage have generated C-point.
Figure 5-25 Instructions plate flow chart
Gui
a) normal work
Figure 5 ~ 26
b) Pan-dip
Distillation column flooding
Further increase after leakage gas velocity, the bubble formation in the Tower Jin-layer board, began to entrainment, when the gas velocity as large as fog Mo
Entrainment by severe flooding will appear Ⅱ. Flooding is more common when a large gas-liquid loads are increased to prevent the liquid downstream of steam, the next
A tower of liquid board rushed to the tower on a piece of board, as shown in Figure 5-26. When the tower over on-board increase in the accumulation of liquid gas pressure drop
And downcomer in the liquid flow resistance losses, the liquid from the downcomer in the pouring down, so when the tower flooding pressure, resistance
And a substantial level, such as the cyclical fluctuations in the purity of the destruction.
Apart from operational factors, plate manufacturing defects, plug the overflow channel, tray rust, dirt and solid particles (if CO.,
HO particles entering the tower) is caused by blockage of the causes of flooding.
5. Performance Chart
Structural parameters of each tray column has been designed to maintain its normal characteristics of gas-liquid load must be limited to a certain extent
Inside, outside its zone of stability, the tower will not be able to normal operation, Chuan
A significant drop in transfer efficiency. Under the conditions of the various limits of the steam load
And liquid load L relations, plotted in the coordinates of a work,
Thistle may allow the load range of graphics, the graphics as
Load performance plans.
Sieve-plate column load performance chart shown in Figure 5-27. With
Following curve to determine the limits of its operating area of stability.
a. Liquid crystal line. Operation of this line is the lower limit of gas velocity, low -
This line, gas and liquid can not play the role of the normal contacts.
. Mo fog over the central belt line. Gas velocity over the velvet-resistant,
Figure 5-27 female Dutch VST Performance Chart
Fog taboo dance with more than permitted (o.1 kg for general distillation
Liquid / lkg gases), which reduces the additional tray efficiency.
c. Minimum liquid line. Is the minimum liquid load on the liquid overflow weir height of the minimum liquid height, which is lower than this limit,
Liquid column can not be guaranteed should be evenly distributed.
d. Liquid limit line. Under the downcomer residence time within the request, beyond this line, as a result of reduced back-mixing gas tower
Plate efficiency. Trays or liquid layer to calculate the maximum height of the ceiling line liquid rim
e. Pan-line solution. Under the downcomer height with foam / West for the relative weight of the foam layer, the general matter of =
O. 5, should be less than the tower on plate spacing. And export of high weir ^. And the. Gl beyond the line from the flooding.
As shown in Figure 5-27 in the shadow of the region, that is, the stable operation region tower. Figure 5-27 Si ratio of the line position can be
Tray adjustment and changes in structural parameters, Figure 5-28 for
M VST performance chart of a typical load.
5-28 indiscriminately have downcomer flow of the plate or wear plate
Trees for the performance of a typical map
(The rate of ring Diagram for the President, the unit found to have been buried choice)
Figure 5-29 ASU dig under the tower screen
Limits of stability
The Soviet Union a number of air separation plant under the tower Canon load chart, as shown in Figure 5-2g.
Operating line. _ Set for the operation of liquid-gas ratio process / work for the set value, the operating line in Figure 5-27 is available through 0
Points of a straight line, said. Operating line OA and the shadow of the border area for the operation of intersection, the lower limit, that is, a maximum of flooding, the lower limit
For leakage.
Normal tower design, operation should be located in the shadow of the central zone, has a good range of shells. Operating area of the stability of Tajikistan
Cui Xiao-tray with various values are different, the efficiency curve and the existence of such. Mass transfer efficiency will be regional.
Heat transfer. Configuration space plate tower tower packing tower faster than the high production capacity and therefore large, but a larger pressure drop. Larger diameter towers, mining
With plate-type towers Liu light weight, low cost. Maintenance clean-up easy. Enlarge the diameter of tray column, the tray efficiency of relatively stable. Plate
Tower is a tower plate of a wide range of tower equipment.
Sieve tray column can be divided into rhyme have downcomer and downcomer tube-free (to wear streaming tray) two broad categories. There are tubular downcomer tray.
Between the tray for the liquid through the downcomer, the liquid on each plate tower height high weir overflow weir can be adjusted a certain
Flexibility in the scope of the operation, higher efficiency.
Wear plate flow, gas-liquid two-phase at the same time by the Tower board
By a number of holes (such as the inverted sieve) through the reverse please touch pond. Knot
The saved configuration downcomer to deal with power boats, drop a small, but
Tray efficiency and operational flexibility are subject to - will be restricted.
For air distillation tower before the sieve plate are liquid shallot are open pipe
Sieve plate tower. .
A
, Fu Pei tectonic plate
Sieve plate tower by the tower and plate composition, Figure 5-13
The structure shown by the sieve plate, overflow weir, downcomer
And so on.
1. Sieve
, To
Head of a 13 plate column 5 indicate intercalated
l, overflow weir possession 2. Import weir 3. Plate
Sieve diameter d is generally 0.8 ~ 1.3 mm,
Range.
Opening rate is
~ 0 ~ 0.907
A i
Where. 11 sieve size
.
- - Opening area
Triangular in shape with Sieve. Center Spacing t sieve in the 1.2 ~ 4 mm
Openings rate is generally 0.05 ≤ ≤ O. 15, namely t / do =
2.5 ~ 4 t / <2, plate is not stable operation. Opening rate
Small, hole-speed, and tray pressure drop caused by fog easily execute large and liquid entrainment
Pan, Yi each other in the disturbance caused by air currents, small aperture and small opening rate
Flexible operation of the plate. Openings rate is high, speed small hole, easy production
Health leakage, entrainment of small, narrow operating range.
Tower board, the next paragraph larger load changes, the above rhyme Sieve
Diameter and hole spacing can be different, so that the whole tower has a good stable operation
Will be offering.
2. Liquid flow pattern
Waterloo won
Weeping Circumfluent cut plate-type tray
Figure 5 - 14 circulation and convection-style tray
Trays are commonly used in fluid flow and convective flow of the ring are shown in Figure 5-14. Annular flow tray
Both inside and outside diameter of the tube than in the 2.4 ~ 3 Fan circle.
According to the liquid flow channel can be divided into single-flow type, double type, the four flow patterns and so on, as shown in Figure 5-15. Liquid by liquid flow by the number of negative
Select the size of a single load flow model for small-scale air separation equipment, tower b15oo mm in diameter below Shuangliu separate type for the medium-air
Preparation, Tower Drive in the t, 2ooomm about cutting the four streams for large-scale air separation equipment, tower above the track at ~ 30001TtlTt.
0 @ ① ① @ ④ a @
Single-flow pattern
(Of water)
Four dual-flow water-based single-flow-type four-flow pattern Shuangliu
(Convection) (convection) (Circulation) (Circulation) (Circulation)
5-15 Luoyu solid plate flow pattern (arrows hit Sui body for the flow)
3. Plate spacing
Asked the size of plate and liquid from the pan and fog volume the size of attachments-soo. Plate spacing, and of production capacity, tray efficiency, Cao
Flexibility, installation maintenance and other benefits, but it will increase the tower height, increased metal consumption, high cost.
Tray spacing of 70 ~ 200 mm in the framework of
4. A run-off devices
Overflow device includes downcomer, and liquid overflow weir plate and other components.
Downcomer (overflow pipe) the form of straight and oblique overflow overflow, there are flat plate by the liquid and the concave shape. The main air distillation column an overflow pipe
There are three types, such as the circle shown in 5-16.
I also can weir liquid evenly into the tray.
Trays are equipped with overflow weir (weir exports), which Trays
There are some clear liquid height and liquid evenly on the board in the tower
Distribution. Overflow weir height of 5 ~ lSmm Fan in the country, for large
Type tower, due to the overflow tower on the board too much strength, high flow weir on
High, the use of small overflow weir height values.
Affect the length of overflow weir overflow intensity (in the long weir
Flow known as the overflow of the liquid flow strength), Yi-Ying intensity,
Liquid height on the weir overflow weir major also affects the long Trays
Uniform flow distribution. Weir length and the ratio of tower diameter, there must be
For: single-flow type, weir length of the tower diameter 0.6 ~ O. 8-fold, Shuangliu
Type, weir length of Tower Drive 0.5 ~ 0.7-fold. Different weir long bow
Shaped downcomer downcomer area and width as shown in Figure 5-l7.
Fluid in the overflow plate and pipe ramp there is leakage at the bottom of the tear open
Hole in order to rule out the fluid when parking. Figure 5-17 become not downcomer of the nomogram
Plate fixation of the structure and materials related to love. Copper plate with the two upper and lower clamping ring fixed in the cylinder on
Rolled out between the two slot, copper ring can be pressed into oval-shaped control, fixed-tin solder. Upper and lower aluminum tray are
Kok fixed, there is a simplified rolling groove, with isolated heavy atmosphere welding as shown in Figure 5-l8.
The level of sieve plate column degrees of impact on the work, degree requirements for the level of ~ / looo around.
5. Linde sieve
Figure 5-19 sieve for Linde diagram of the structure characterized by:
(1) in the liquid to enter the area, will be raised tray made of the Taiwan oblique-shaped bubble devices, reducing the height of the liquid, the entire tower
The gas distribution plate, full of gas-liquid contact. Ordinary plate surface as a result of higher liquid to enter the Department, which easily give rise to leakage,
Large number of gas exit through the lower surface, causing an increase in fog entrainment to punish, the impact of tray efficiency. Linde sieve plate and the general
UAE
. ) (| Xi-bound
Figure 5-19 sieve Linde
-43
L) l knot braided floor sweep handle tower
Figure 5 - 18 the way the draw tower
Have possession of commonly used twisted tower face off
Yan poor distribution of recorded lazy j
Common plate area of imports slightly
Possession, the district head on blow j
Lin Lu uniform foam plate
Level and steam flow to punish
5 ~ 20 Linde circle plate with ordinary bubble map layer 5-2l mobile sub -
Plate compared the situation of the movement of cloth
Win the state of physical science as shown in Figure 5-2O.
(2) in the tower on the board with a certain number of blind holes oriented style. Hole-oriented direction and liquid flow in the tower on the board
Direction of gas flow through the guide hole to promote, you can reduce the level gap, but also can adjust the height of the bubble
In addition, Linde plate on the plate with the general movement of the bubble layer is different, as shown in Figure 5-2l. Plate on the general flow is
Uneven, Yun tray center to a larger flow rate of liquid flow on both sides of the slow flow of liquid. Trapped in the foam layer tray
The residence time is different, with the result that under the open tray efficiency. Linde plate to maintain uniform liquid residence time, and stop
Leave time from the tower of the uniformity of the impact of too small diameter, the plate and high efficiency.
Linde sieve evenly bubbling liquid layer, surface gradient of small, small pressure drop, processing capacity, and the county have a good mass transfer effects,
Is a good performance of the plate.
Distillation separation plant some room to catch the technical specifications in Table 6-4 Table 5-5 and Table 5-6.
= Have downcomer performance of sieve-plate column
1. Tap plate on the liquid structure
Plate on the structure of the gas concentration is divided into three regional t drum f (! 【Layer, foam layer and spicy entrainment, as shown in Figure 5-22.
Network
Table 5-4 China, the low-pressure air separation
ASU Model l KFS a 3Do l KFS a 850-2 l KDON-iooo/ioo ~ KDON a 1500/1500-1
On the tower 'on the tower
Under parts of the tower tower tower tower under the 'l. Crucible 1. 2 3 under the tower
Plate form of speech 'cry cry Ringspot plate plate plate circulation circulation Hao board
Tap plate, Bu Path (mm) 2B5 198 5 to 400 55D 1loD l1100 lg2D 8O0 l140O 1i mbO f1i00
Tower diameter plate (mrt1) 11 215 170 215 35 0): 50 350 450 I 4SO 450 450
Tower-way to one - a 2.3 2.35 2 56 3 1 d 【3 1 4 2.62 1 78I 3.1
I overflow the number of H (10) L 1 1 1 1 1 l 1 1 1 1 l
Sieve diameter d0 (mm) 0.8 0.8 0. I 0 9 D. g 1 D. 9 1 1 l l 1
Hole center box t (m m) 3 25 3 25 3 25 3. 3 25 3 25 3 25 3.25
A high degree of ring closure starting a (mm) 10 10 10 10
Hang overflow weir height (mm) l5 1; 15 15 15 1 0 1D 10 i0 1 J
Imports of high-jiang (mm) 18 l8 2o 20 40 J 4 u 4D (0 25 l 2
Austin from the tray (mm) 75 7; 80 80 110 I 11. j 90 』90 9 3 00 11 0 l l10
Wooden tower on the t 1 - Po tower above, 2 - expansion of the air gap own import export position Bute Ko Kr, 3 - bottom out on the location of the expansion of air imports.
Table 5-5 Linde AG 10000m. / H, 30000mS / h at the main parameters of distillation equipment
§ l lO000m ~ / h 3O0O0 ¨ m '/ h
On Tap 'on Tap'
Under the tower under the tower site
l l 2 3 4 j 5 l 2 I 3 4 S
385O 3250
4 2
1.1 1.1
3.2 3.2
_
7 i lD. 7 10.7
Tower of Tibetan plate diameter (mm) 1245 Z450 l24SD Z450) 245D 225D 2850 385 0 l38S0
Population overflow (10) 1 2 2 2 4 4) 4
Sieve diameter (mm) 1.1 0 9 0 g 0 9I 1.1 0.9 1.1 0.9 0.9
Hole Center Distance (mm) 3.2I 2.1 2.1 3 2 3.2 3.2 2 85 2. 1 2.1
Opening rate () l0.7I l6.7 l6.7 7. 1O. 7 7.2 13.5 16.7) 16.7
Ke plate distance (mtiTt) l 140 l 20 0 I 200 1BO l 140 180 l3O 180 l 160 120 1GO
Wood tower) 1 - - Des tower above ** sieve-type air-Dan Equipment
2 - - mounted air import export position to share the location of Holland
3 - - Liao together to ring the location of the air space of imports import location
4 - Dan pumping distillate heavy atmosphere thistle population expansion of the location of the location of the air imports
5 on the bottom of a heavy atmosphere over who smoke Xi I: 1 position
Sang bubbling layer is affixed to plate layer of a layer of clear liquid, bubbles floating in its continuing. Foam layer in the layer above the bubble, was bee
Nest-like structure, and its intense disturbance in the liquid bubbles, bubble formation and frequently break down, steam and liquid droplets contact the surface of a large,
Mass transfer and heat transfer is a major occasion. Fog foam layer in the foam layer above the liquid jet into a fog was spread over the gas implicated in the last few
Droplet volume of steam to the upper plate was referred to as entrainment. Entrainment of liquid back-mixing as a result of that component by the oxygen concentration after
The introduction of liquid back to the lower component of the liquid oxygen, and the mass transfer efficiency caused by this restriction in the volume entrainment 0.1 kg
Liquid / l kg of gas below the guarantee to limit the flow of steam.
Different liquid load plate, the foam layer height and air speed V of the relationship between tower as 5-23 ring run by nJ. Know
Oxygen concentration in the liquid fraction of foam the size of the impact of a great height.
KD0N a 320 o/320 0 KFD a'10OO KDoN a 1000 o / looo 0
On the tower tower tower
. F under the tower tower
l 2 3 1 2 I 3 2 3
Sieve plate circulation flow circulation Tanzania tuna plate
110O 1800 1809 '18O0 1500 2500 2304 2050 18O0 3200 3200 l 2850
450 804 800 800 5 0 85 0 850 70 70 12O0 120 f 1O00
2. t5 0. 2 25 2 25 3 2 8d 2 i 2 03 2.56 2.8 2 67J 2 83
2 2 l 2 2 2 2 0
O. 9 1 1 1.1 1 0 g
3.25 3.25 3.25l 3 25 3.25 3 25 3.25 3.25 3 25 3.25 3.25 3.25
6 6 6 『6 '6) 4 5 3 3 3 3
6 I 8 7 1l t 8 l0 5 5 5 5
16 25 19) 21 21 21 l 19 21 ^ 0 4a '' O
9O 13O 1 groan 【10O 90 110 l 11fJ 100 l30 1 30 0 【130
2. Pressure Drop
Tray is the increased resistance of steam through a tray that must be overcome resistance. Plate resistance is composed of three parts, namely, 1000
Plate resistance, resistance and bubbling liquid layer when the surface tension of the liquid to overcome the pressure head.
Sieve tray stem resistance and speed of steam. Fluid resistance with Tower repeated on-board liquid layer and the hydrostatic head of the state of the bubble on the
When the opening rate of a certain plate to increase the speed of air tower. Increase the resistance to plate, as shown in Figure 5-24. Air distillation
The pressure drop in tray for a 200 ~ 350 Pa (20 ~ 35mm H2O).
3. Surface gradient
Granted on the liquid flow in the tower, in order to overcome the flow resistance Trays gradient liquid form. Annular flow for the plate not only
Gradient surface-way measures, but also around the center as a result of fluid flow generated by rotating the radial gradient surface with gradient surface overflow
Intensity increases, but also with the fluid flow path of growth increased with the level of degrees of the tray. The impact of surface gradient
Gas in the tower granted through the uniform, thus affecting the mass transfer efficiency, the design of surface gradient requirement of no more than dry plate resistance 5O.
4. The operation of plate
Plate operation, the liquid cross-flow weirs by the import tray off, fully in contact with the gas from the downcomer into the lower tray
In the downcomer tube should have sufficient time for the separation bubble and the clear liquid into a gas break, if the liquid load increased, the liquid in the downcomer
Speed up the flow rate, residence time should be shortened, when the stop time so that the liquid entrainment Liu bubble separation time was taken to
The lower tray, it will reduce the separation effect, then known as the downcomer overload.
Downcomer ugly for a high level within
B = ^ + ho 10 + +
Where ^. - The height of overflow weir
ho =- - weir height on the flow
- - Import and export of the surface gradient between the weir
k - the gas pressure drop through a plate
^ - Liquid through the downcomer resistance losses
Table 5-6 "V-shape space next to God did not prepare the main parameters of distillation column
H Ⅱ I --
I 1 go 0o '
(1) fine tower wall diameter (13-1m) lg0 0
(2) on the number of overflow tube (10)
(3) plate with the distance (ram) i 00
(4) degree of air tower building (m / s) j
(5) Qiongzhuea center hole diameter x distance (ram)
(6) Sieve speed (m / s)!
(7) weir height on the surface (ram) (
(8) plate on the surface stability and business degrees Ohm)
(1) sperm straight-way tower Po (m m)
(2) the number of overflow (10)
(3) tower plate spacing (mm)
(4) degree of air tower building (m / s)
(5) Sieve heart from the hole diameter × cmm)
(6) Sieve speed (m / s)
(7) weir to the liquid and virtual (m131) I
(8) plate on the surface stability and a high degree of respect (mil1) 1
Large liquid load, h? D, and ^ d are increased in the liquid downcomer on d also increased, and vice versa.
When the gas velocity is low, the tower on the board all of the liquid falling from the sieve, and Tajikistan on the board without liquid layer, increasing gas velocity, a tray I:
Liquid layer at this time began to take shape as the liquid seal "(mid-point of Figure 5-25). Further increasing gas velocity, liquid will soon reach the weir high pressure drop
Has been a corresponding increase (the figure 'B point), this time to achieve the maximum liquid seal. Increased gas and then deep, on the part of the liquid over the overflow weir from the drop
Liquid pipe flow, the other part to the next by a sieve plate leakage, a phenomenon known as the. Leakage. "Leakage of the plate is not uniform
And part of the steam through the sieve, sieve in the other part of leakage, and the location is not fixed, the changes at any time. Leakage
Volume with the increase of gas velocity is reduced, sieve was air blowing increasing the degree of opening, when the gas velocity increased to the full blown Sieve
Opened, the leakage is stopped, the figure 'B is a sieve after blowing open the process of gradually increasing the degree, although this stage of gas
Increasing load, but the gas velocity through the sieve is always the same, so do not drop with the increase of gas velocity increased, reached the figure劐
C points as the leakage point cut at this time of the gas velocity to maintain the liquid can not leak in the tower on the board, gas velocity Xiaoyu leakage have generated C-point.
Figure 5-25 Instructions plate flow chart
Gui
a) normal work
Figure 5 ~ 26
b) Pan-dip
Distillation column flooding
Further increase after leakage gas velocity, the bubble formation in the Tower Jin-layer board, began to entrainment, when the gas velocity as large as fog Mo
Entrainment by severe flooding will appear Ⅱ. Flooding is more common when a large gas-liquid loads are increased to prevent the liquid downstream of steam, the next
A tower of liquid board rushed to the tower on a piece of board, as shown in Figure 5-26. When the tower over on-board increase in the accumulation of liquid gas pressure drop
And downcomer in the liquid flow resistance losses, the liquid from the downcomer in the pouring down, so when the tower flooding pressure, resistance
And a substantial level, such as the cyclical fluctuations in the purity of the destruction.
Apart from operational factors, plate manufacturing defects, plug the overflow channel, tray rust, dirt and solid particles (if CO.,
HO particles entering the tower) is caused by blockage of the causes of flooding.
5. Performance Chart
Structural parameters of each tray column has been designed to maintain its normal characteristics of gas-liquid load must be limited to a certain extent
Inside, outside its zone of stability, the tower will not be able to normal operation, Chuan
A significant drop in transfer efficiency. Under the conditions of the various limits of the steam load
And liquid load L relations, plotted in the coordinates of a work,
Thistle may allow the load range of graphics, the graphics as
Load performance plans.
Sieve-plate column load performance chart shown in Figure 5-27. With
Following curve to determine the limits of its operating area of stability.
a. Liquid crystal line. Operation of this line is the lower limit of gas velocity, low -
This line, gas and liquid can not play the role of the normal contacts.
. Mo fog over the central belt line. Gas velocity over the velvet-resistant,
Figure 5-27 female Dutch VST Performance Chart
Fog taboo dance with more than permitted (o.1 kg for general distillation
Liquid / lkg gases), which reduces the additional tray efficiency.
c. Minimum liquid line. Is the minimum liquid load on the liquid overflow weir height of the minimum liquid height, which is lower than this limit,
Liquid column can not be guaranteed should be evenly distributed.
d. Liquid limit line. Under the downcomer residence time within the request, beyond this line, as a result of reduced back-mixing gas tower
Plate efficiency. Trays or liquid layer to calculate the maximum height of the ceiling line liquid rim
e. Pan-line solution. Under the downcomer height with foam / West for the relative weight of the foam layer, the general matter of =
O. 5, should be less than the tower on plate spacing. And export of high weir ^. And the. Gl beyond the line from the flooding.
As shown in Figure 5-27 in the shadow of the region, that is, the stable operation region tower. Figure 5-27 Si ratio of the line position can be
Tray adjustment and changes in structural parameters, Figure 5-28 for
M VST performance chart of a typical load.
5-28 indiscriminately have downcomer flow of the plate or wear plate
Trees for the performance of a typical map
(The rate of ring Diagram for the President, the unit found to have been buried choice)
Figure 5-29 ASU dig under the tower screen
Limits of stability
The Soviet Union a number of air separation plant under the tower Canon load chart, as shown in Figure 5-2g.
Operating line. _ Set for the operation of liquid-gas ratio process / work for the set value, the operating line in Figure 5-27 is available through 0
Points of a straight line, said. Operating line OA and the shadow of the border area for the operation of intersection, the lower limit, that is, a maximum of flooding, the lower limit
For leakage.
Normal tower design, operation should be located in the shadow of the central zone, has a good range of shells. Operating area of the stability of Tajikistan
Cui Xiao-tray with various values are different, the efficiency curve and the existence of such. Mass transfer efficiency will be regional.