A kind of tower tray of uniformly distributed retention period of liquid
The present invention relates to a kind of core component of plate column--tower tray.
Plate column is a kind of purposes gas-liquid mass transfer (contact) equipment very widely, occupies important position in industries such as oil refining, petrochemical industry and chemical fertilizer.As everyone knows, plate column is a round structure, is provided with circular downspout, and forms two arc areas in the card both sides, and this just structure makes it exist a significant defective on card liquid is uniform:
(1) for the single overflow tower tray, because chord downcomer has the afflux effect of liquid, the liquid outlet quantity of downspout end opening zone line is 1.5~3.5 times of arc edges at two ends zone, simultaneously, because the stream of the liquid on the card has also successively experienced stream and two processes of contracted flow of expanding, and liquid stream is much longer along the distance of diameter along the distance of circumference, therefore, the tower tray middle part forms channel, tower tray both sides arc areas forms and refluxes and metastable viscous flow dead band, causes that the time of staying of liquid has very big difference on the card.Fig. 1 is liquid residence time distribution schematic diagram on the card.
(2), two kinds of different situations are arranged then for the double overflow tower tray:
Exit weir is at the tower tray of centre, liquid on the tower tray is moving to the central exit weir flow by the both sides chord downcomer, uneven and the mobile channel that will cause the card zone line of expansion thereupon of the caused end opening fluid of its chord downcomer, and in card both sides arc area formation backflow and metastable viscous flow dead band, also make the time of staying distribution of liquid on the card have very big difference, see Fig. 2;
Exit weir is at the tower tray of both sides, liquid on the tower tray by the centre to two side flow, because of its downspout is a rectangle, downspout end opening liquid outlet quantity is uniform basically, and card liquid stream only experiences single contracted flow process, the liquid backflow phenomenon no longer takes place, and only the length because of liquid stream journey makes the card liquid residence time variant slightly, sees Fig. 3.
In order to keep the higher effective tower section to amass the l of industrial tower tray
w/ D (weir length/tower diameter) only is 0.55~0.7 usually, and this just makes on this type of tower tray the time of staying of liquid more irregular, becomes the major obstacle of further raising plate efficiency.Numerous scientific and technical personnel once were devoted to study the equally distributed plate column tower tray of various liquid in order to improve the plate efficiency of plate column, wherein comparatively typically had following several:
1.Muller E.A., Chem.Eng.Comm., 1988,74:195~161 propose chord downcomer baffle plate end opening is made the shape of both sides gap, so as to increasing the flow quantity in chord downcomer wedge angle district;
2.Biddulph M.W., Chem.Eng.Prog., a baffle plate is set up in 1993,89 (12): 56~60 suggestions in chord downcomer inside, so that the flow regime in the chord downcomer is able to minor betterment;
3. yellow clean, Yu Guocong, petrochemical industry, disclose a kind of at card upper edge liquid flow path direction deflector be set so as to dredging liquor stream with stop the method for backflow at 1984,13 (3): 182~189.
It is limited that yet the liquid of above-mentioned all methods flows uniform effect, can not reach the purpose of uniformly distributed retention period of liquid on the tower tray exactly.
The objective of the invention is to disclose a kind of tower tray that on tower tray, is provided with liquid stream uniform board, card liquid residence time difference is controlled in 8%, make the plate efficiency of existing industrial tower that 5~10% raising can be arranged.
Design of the present invention is such: the chord downcomer liquid outlet is provided with the liquid stream uniform board that a centre tilts to both sides on tower tray, control certain height, length, shape and gradient, make liquid before entering tower tray, carry out the even distribution of a liquid earlier, simultaneously, regulation and control enter the fluid flow of each position of card effectively, can make the mobile time of staying of liquid on tower tray be tending towards even.
Said card liquid residence time evenly distributes, and is meant the liquid residence time unanimity generally from the downspout end opening to each streamline between the exit weir on the whole tower tray.The tower tray that has only the card uniformly distributed retention period could satisfy the uniform requirement of contact in actual motion, to reach the purpose that improves plate efficiency.
According to above-mentioned design, the inventor has proposed to implement concrete technical scheme of the present invention based on the long-term experiment research of large-scale tower tray cold model unit, is described below:
The said tower tray of the present invention is an assembly, mainly is made up of column plate, gas-liquid contact element, downspout, exit weir and liquid stream uniform board.
Fig. 4 is the schematic diagram of single overflow tower tray.Fig. 5 be among Fig. 4 A-A to diagrammatic sketch.
Fig. 6 is the schematic diagram of double overflow exit weir at the tower tray of centre.Fig. 7 be among Fig. 6 B-B to diagrammatic sketch.
Among the figure:
The 1------tower body
The 2------downspout
The 3-----column plate
4------liquid stream uniform board
The 5-----exit weir
The length of l-----liquid stream uniform board 4
The height of h-----liquid stream uniform board 4
l
wThe length of-----exit weir 5
Said liquid stream uniform board 4 is the stripe board that a centre tilts to both sides.Fig. 8 is the schematic diagram of said liquid stream uniform board 4.h
qHeight for sloping portion.The domatic curve is an oval part.Said liquid stream uniform board 4 is arranged at the liquid outlet of downspout 2, and the spacing d between liquid stream uniform board 4 and downspout 2 end openings is an important parameters, at liquid flowing strength Γ=0.5~40m
3Under the condition of/m.h, d=5~80mm.For making liquid stream can not form resistance control in this interval, d should be more than or equal to h
0, h
0Be the spacing between downspout 2 lower edges and the column plate 3.
The height h and the clear liquid layer height h of liquid stream uniform board 4
LRelevant, available following formula is determined:
H=h
L+ (10~20) clear liquid layer height h
LComputational methods in general tower design data, narration is arranged all, repeat no more herein.The height h of sloping portion
qAnd the pass between the h is:
h
q/h=0.05~0.60。
The bottom of said liquid stream uniform board 4 is fixed on the column plate 3, and two ends can be connected with tower body 1, also can not be connected.
Said liquid stream uniform board 4 also can adopt following three kinds of forms:
(1) single domatic, Fig. 9 are the schematic diagram of single domatic liquid stream uniform board 4.
(2) bent domatic, Figure 10 are the schematic diagram of bent domatic liquid stream uniform board 4.
(3) two domatics, Figure 11 are the schematic diagram of two domatic liquid stream uniform boards 4.Among the figure:
l
1, l
2, l
3, l
4,--the length of-liquid stream uniform board 4 sloping portions
h
1, h
2, h
3, h
4,--the height of liquid stream uniform board 4 sloping portions
Said liquid stream uniform board 4 can have different height, length, shape and gradient under different liquid stream conditions:
1. under medium liquid flowing strength, as liquid flowing strength Γ=3~14m
3During/m.h, the two ends of liquid stream uniform board 4 are connected with tower body 1, and its length l can be according to d and l
wDetermined that by geometrical relationship the relation between the length is as follows:
Single domatic: l
1/ l=0.04~0.50
Two domatics: l
3/ l=0.03~0.18 l
4/ l=0.06~0.50
Bent domatic: l
2/ l=0.04~0.50
The height relationships of each slope section is as follows:
Single domatic: h
1/ h=0.05~0.60
Two domatics: h
3/ h=0.02~0.38 h
4/ h=0.05~0.58
Bent domatic: h
2/ h=0.05~0.60
The domatic of bent domatic is an oval part.
2. under big liquid flowing strength, as liquid flowing strength Γ>14m
3During/m.h, the two ends of liquid stream uniform board 4 no longer are connected with tower body 1, leave l
6Breach, so that bigger both sides fluid course to be provided, offset the backflow of card both sides arc area liquid, can reach the purpose of card uniformly distributed retention period of liquid.As shown in figure 12.
Among the figure:
l
5,----liquid stream uniform board 4 sloping portions length
l
6Distance between-----liquid stream uniform board 4 and the tower body 1
h
5The height of-----liquid stream uniform board 4 sloping portions
Each parameter of length and height is as follows:
l
5/l=0.05~0.50 l
6/l=0.04~0.20
h
5/h=0.15~0.55
The length l of this liquid stream uniform board 4 can be according to l
w, d and l
6/ l is determined by geometrical relationship.
The form of this liquid stream uniform board 4 can be single domatic, bent domatic or two domatic.
3. under little liquid flowing strength, as liquid flowing strength Γ<3m
3During/m.h, because the liquid height is lower on the weir, the top of liquid stream uniform board 4 can be provided with tooth mouth, ladder way or square mouth, and uneven to eliminate the liquid stream that causes because of location tolerance, its two ends are connected with tower body 1.Figure 13 is the local diagrammatic sketch of liquid stream uniform board 4 for this reason.
Parameter is as follows: e=5~30mm f=5~40mm
g=0~fmm i=0~10fmm
The said liquid stream of the present invention uniform board 4 can be used for the single overflow tower tray, also can be used for the double overflow tower tray of exit weir 5 in the centre.For the double overflow tower tray of exit weir 5 in both sides, because of the downspout of upper strata tower tray is a rectangle, and liquid stream only experiences the contracted flow process, exit weir 5 need only be made into the form of liquid stream uniform board 4, just can obtain the current-sharing effect of comparatively being satisfied with.
The present invention can be used for various types of plate columns, as sieve plate, valve tray and bubble cap tray etc.
The said tower tray of the present invention is investigated through large-scale cold model unit test and industrial tower practical application, and the result shows to have following advantage:
1. current-sharing is effective, can eliminate the channel and the backflow of card liquid effectively, and the time of staying difference of card liquid is controlled in 8%;
2. current-sharing effect dependence self HYDRODYNAMIC CONDITION RELATING TO realizes;
3. adaptability is strong, can be used for various types of plate columns, as sieve plate, valve tray and bubble cap tray etc.;
4. adopt the zero dimension structural parameters, all can be suitable for for the plate column of different tower diameters and various liquid stream condition;
5. simple, be particularly useful for of the scene transformation of factory's shutdown of short term to old tower;
The said tower tray of the present invention can be widely used in operating process such as rectifying, absorption, desorb, caloic transmission, is a kind of plate column tower tray with broad prospect of application.
Below will the present invention is further illustrated by embodiment.
Embodiment 1
Certain fractional column of float valve, the chord downcomer setting adopts liquid stream uniform board shown in Figure 11 to do the uniform transformation of card liquid stream, and every technical parameter is as follows:
The tower inside diameter D 1000mm long l in weir
w620mm
Height of weir h
w25mm liquid flowing strength Γ 8.06m
3/ m.h
The installation site d 18.55mm of liquid stream uniform board 4
The height h 26mm of liquid stream uniform board 4
The length l 664mm of liquid stream uniform board 4, two ends are connected with tower body 1
l
3/l=0.12?l
4/l=0.28?h
3/h=0.077?h
4/h=0.27
Whole tower trays of this rectifying column are taked as above current-sharing setting, and recording the card liquid residence time is 12 ± 0.5 seconds, is guaranteeing that production capacity has improved 10% under the product quality premise.
Embodiment 2
Certain woods moral plate rectifying column, the chord downcomer setting, card liquid is in serious inhomogeneous state, adopts liquid stream uniform board shown in Figure 12, and every technical parameter is as follows:
The tower inside diameter D 1800mm long l in weir
w990mm
Height of weir h
w30mm liquid flowing strength Γ 22.25m
3/ m.h
The installation site d 30mm of liquid stream uniform board 4
Substantially the high h 45mm of liquid stream uniform board 4
The length l 1076mm of liquid stream uniform board 4, two ends are not connected with tower body 1, stay
Jagged is l
6
l
5/l=0.1?l
6/l=0.075?h
5/h=0.25
After taking as above current-sharing to be provided with, card has not had channel, and original backflow phenomenon disappears, card liquid stream uniformity.
Embodiment 3
Diameter is the bubble-cap formula ammonia absorber of 1600mm, is absorbent with soft water, reclaims the NH in the unstripped gas
3And CO
2, to avoid the pollution of ammonia nitrogen waste water to environment.Adopt the said liquid stream uniform board with tooth mouth of Figure 13 of the present invention, its every technical parameter is as follows:
The tower inside diameter D 1600mm long l in weir
w1040mm
Height of weir h
w70mm liquid flowing strength Γ 3.23m
3/ m.h
The installation site d 15mm of liquid stream uniform board 4
Substantially the high h 70mm of liquid stream uniform board 4
The length l 1074mm of liquid stream uniform board 4, two ends are connected with tower body 1
l
1/l=0.15?h
1/h=0.12
Tooth mouth parameter e=16mm f=18.5mm
i=0 g=0
At system balancing soft water 2.8m
3The working condition of/h is operation down, is summer of 36 ℃ in environment temperature, NH in the tail gas
3And CO
2Index still can meet the requirements, total system ammonia nitrogen waste water discharging is zero.
Embodiment 4
The long tower diameter ratio in less weir has been taked on certain large-scale double overflow absorption tower during design, in service because of excessive liquid flowing strength causes card liquid stream serious uneven, now adopts technology of the present invention to flow uniform transformation as liquid.
To the tower tray of exit weir 5 in the centre, liquid stream uniform board 4 as shown in figure 12 is set near the chord downcomer end opening of both sides, every technical parameter is as follows:
Tower inside diameter D 2400mm
Long (both sides the exit weir)/tower diameter 0.58 in weir
Height of weir h
w15mm liquid flowing strength Γ 43m
3/ m.h
The installation site d 45mm of liquid stream uniform board 4
Substantially the high h 20mm of liquid stream uniform board 4
The length l 1074mm of liquid stream uniform board 4, two ends are not connected with tower body 1,
Leaving certain gaps uncovered by the economic plan is l
6
l
5/l=0.15 l
6/l=0.12
h
5/h=0.30
To the tower tray of exit weir 5 in both sides, liquid only experiences the contracted flow process, and no channel and backflow are only made appropriate reconstruction to exit weir 5, gushes height with the part of eliminating contracted flow liquid.Exit weir 5 adopts single domatic shown in Figure 9, and technical parameter is as follows: l
1/ l=0.15 h
1/ h=0.14
Adopt the double overflow tower tray of above technology, satisfied liquid and flowed equally distributed requirement.