DD270813A3 - DEVICE FOR THE HOMOGENEOUS DISTRIBUTION OF A GAS / LIQUID MIXTURE - Google Patents

Abstract

The invention relates to a device for distributing a multiphase mixture to a kreisfoermigen cross-section. A preferred field of application are standing apparatuses with longitudinal tubing. The aim is to ensure a high heat exchanger on the pipe side or a high mass transfer in standing apparatuses that are vertically pervaded. It is an object to provide a device for uniform application of a kreisfoermigen cross-section while maintaining a minimal pressure loss and ease of assembly and disassembly feasibility. This is achieved by arranging a stepped duplex and a conical transition piece in the upper region of the homogenizer, followed by resistor bodies and lower duplexes. There is again a cross-sectional widening and the arrangement of a rectifier, to which a consisting of up to 5 concentrically arranged relatively thin-walled cones existing diffuser connects. The ratio of outlet and inlet cross-section of each diffuser channel is smaller than the ratio of the outlet to inlet cross-section of the cones adjacent to the inside. Fig. 1

Description

a) Title of the invention

Device for homogeneous distribution of a gas / toluene mixture • 5

b) Field of application of the invention

The invention relates to a device for uniform distribution eine flowing, consisting of liquid and gaseous components existing mixture on a surface of circular cross-section, z. B. odor on the surface of a Katalysatorohüttung outgoing from a tube sheet with an approximately circular tube mirror Rohrbündelrchre.

The supply of the two-phase mixture takes place via a zentrisoh arranged vertical inlet channel circular cross-section in Kopfbereioh the stationary apparatus at the lower end is a means for homogenizing the partially phase-separated flow, which is a plurality of concentric cones be standing diffuser for low-loss delay the stream ansohließt over the subsequent circular cross-section with a uniform mixture distribution.

The device according to the invention is preferably used in standing apparatus with a longitudinal tube bundle or with a catalyst blank, wherein the tube bundle tubes or the catalyst headers are vertically flowed through by the two-phase Gemisoh from above.

These are ζ. B. standing RohrbUndelwärmeUbertrager and hydrokatalytieohe reactors, which are used in plants of petroleum and Karbooheraie.

o) Characteristics of known teohnisohen solutions

There is already known an arrangement for the homogeneous distribution of a flowing gas liquid mixture to a plurality of parallel pipes according to DE-OS 2 232 074.

In this, the gas-liquid gas entering through a pipe then flows through a narrow DUs, whereby the flow velocity increases sharply and the hydrogenation becomes more homogeneous. In the following chamber, the mixture strikes a solid plate which is perpendicular to the main flow stream. The Hisohung is forced to pass radially outward to the edge of the plate, where it is deflected, the gap between plate and outer-t wall flows through and is directed radially inwardly below the plate. The flow is distributed below the plate to the tubes, which is assisted by having a distributor plate with smaller holes in front of the tube plate.

A disadvantage of this known teohnisohen solution affect the Aufreohterhaltung a high flow velocity over almost the entire arrangement and the sharp deflections on the plate and the enormous cross-sectional constriction with subsequent sudden expansion of the distributor plate au3, which leads to a very high overall Druokverlust in the device.

Since in this arrangement, the desired homogeneous distribution is achieved solely by a positive guidance of the flow in narrow cross-sections, an effective mode of operation is possible only in eimm narrowly limited Durohsatzbereioh. At too low a throughput of the misohuman phase, no homogeneous distribution is achieved, while at an increased throughput the pressure loss increases further.

Furthermore, a device for supplying a Oemisohee of liquid and vapor refrigerant according to DD PS 74 557 is known. In this, the liquid steam mixture is passed into an injection chamber, which merges into a Misohkanal.

Duroh a corresponding structural design ensures a high flow rate, so that a phase separation in liquid and steam is prevented. This Gemisoh flows through the ttberetrömöffnung. A diverter directs the Gemisoh perpendicular to the tubes in a feed channel. In the feed channel is maintained again in such a speed, which prevents separation into two • phases, so that all tubes with a liquid Dampfgemieoh approximately the same composition and the same

Amount to be charged.

This known technical solution naohteiligerweise also causes a very high Druokverlust, as over a longer flow channel with deflection, a high Ströraungsgesohgeschwindigkeit is maintained.

Likewise, the application is limited to a narrow throughput range. A disadvantage of this known technical solution is the restriction to reohteokige apparatus cross sections. Also, with this means, a phase-demixed flow can hardly be completely homogenized, but a homogeneous two-phase mixture is presupposed.

It is also a mixed phase distributor for hydrokatalytieohe reactors according to DD-PS 234 562 known. This serves for the uniform distribution of a liquid / gaseous Misohphaae on a fixed catalyst bed. In this device is located in an inflow pipe, a nozzle and then an upper RohrstUok with inner circular rings which rest on retaining plates, and below the Haltebleohe two hollow cylinders are arranged.

This is followed by the upper lower tube piece, in which a plurality of cones with deflecting sheets are arranged on struts. Below the Umlenkbleohes the inner cone a Bnddiffueor is arranged. The upper part of this preparation serves to homogenize the liquid / gaseous flow, while the lower part consisting of cones, deflecting and final diffusers serves to uniformly distribute over the surface of a large diameter catalyst. Accordingly, the device works on the principle of spraying.

This solution has the disadvantage that its effective use is • limited to large diameter reactors at low surface volume flows in the fixed catalyst bed. This is justified by the fact that when using this Misohphasenverteilers in the middle Durohmesserbereioh too high pressure loss occurs and no sufficiently uniform distribution is achieved.

d) Object of the invention

The aim of the invention is to ensure a high pipe-chamber-side heat transfer or a high mass transfer in a stationary apparatus, which vertically from above, from a mixture consisting of gaseous and liquid components, flows through.

e) Presentation of the essence of the invention

According to the object of the invention, the object is to provide a device for uniform application of an area of circular cross-section with respect to a variable within wide limits throughput and also over a wide range variable composition of the two-phase Gemisohes with respect to the proportion of gaseous and liquid com ponents, keeping the Druokverlust minimal

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and the design components of the Horoogenisators and the diffusers against the duroh the flow induced vibration excitation are detuned and the Einriohtung a einfaohe assembly and disassembly guaranteed.

This is essentially achieved by arranging in the upper area of the homogenizer, with an anti-rotating lead distributed circumferentially on the circumference, the cross section of the circular inlet channel at the lower end to a 25 to 50 % reducing and graduated lower nozzle. The upper part of the nozzle narrows to the axis of symmetry at 10 to 20 ° and the lower part, which amounts to 20 to 30 % of the total height of the nozzle, with 40 to 50 "., In the transition zwisohen the sioh different strong narrowing DUsenberei th the stepped upper nozzle A horizontal, radially encircling groove of approximately semicircular cross-section is followed by an enlarged conical transition piece adjacent to the stepped top nozzle, the flow cross-section remaining approximately constant due to a resistance body arranged in this region in a zen-trisoh manner.

The resistance body with a height of about 0.5 ° of the diameter of the circular inlet channel consists of an upper cone-shaped roof with a rounded tip and a lower cylinder stucco. At the level of the lower end of the cone-shaped roof of the resistor body, the conical transition piece is adjoined by a lower nozzle consisting of a lead jacket and narrowing the flow cross-section to 0.4 to 0.6 times the circular inlet channel. After the lower nozzle, there is again a sudden transverse broadening on the diameter of the circular-shaped inlet channel. At a distance of 1 to 2 times the diameter of the circular inlet channel to a aufgobauter of parallel and intersecting Haltebleohen aufgobauter rectifier is arranged to zwisohen in space

Homogenizer and the Pläohe the circular cross-section

a consisting of up to five concentrically arranged relatively thin-walled cones existing diffuser. Zwisohen the thin-walled cones are arranged radially extending thin-walled sheet metal webs.

At the same time, the expansion angles of the two diffuser channels formed per two adjacent cones decrease from the inside to the outside.

By choosing the entry-door gauge of the thin-walled cones and increasing the height of the individual cones, the ratio of exit-to-entry crosses of each diffuser channel is less than the exit-to-entrance ratio of the adjacent cones. At the same time, the exit cross section of the cone, which is closest to the penultimate end, terminates at a distance of 0.1 to 0.3 degrees from the diameter of the circular surface above it.

A particular embodiment of the invention provides that the Antidrallbleohe are arranged in the upper portion of the stepped upper nozzle, end above the groove and have approximately rectangular shape. In this case, the Antidrallbleohe protrude about the 0.1 to 0.3 Faohe Durohmessers of the circular inlet channel into this. Conveniently, at half the height of the lower part of the above nozzle, there is incorporated an approximately half-circular cross-section, the width of which is approximately 0.2 times the width of the groove.

Another feature of the invention is that the resistance body is formed jagged uniformly distributed at its lower end over the gesaroten circumference. The size of the division is 3 to 10 ram. It is further contemplated that the lower nozzle begins at the level of the lower end of the conical roof of the resistor body and narrows at an angle of 10 to 30 ° relative to the axis of symmetry.

The total height of the lower nozzle is approximately 0.5 times the diameter of the circular inlet channel. Furthermore, the nozzle is at its lower edge gleiohmäßig provided on the circumference with thin Sohlitzen and every other Bleohlappen is zwisohen the Sohlitzen up to 30 ° bent over the other Püsenkontur naoh outside. The inlet diameter of the conical transition test is slightly larger than the exit diameter of the upper nozzle. This is designed as a drip edge. 10

f) exercise example

The invention will be described with reference to an exemplary embodiment

explained. The accompanying drawings show in: 15

Inventive device as son; Installation of the device in the head section of a stationary Hoohdruok tube bundle heat exchanger; Detail X of Fig. 1; Pig. 4: geometric conditions on the diffuser;

Top view of the diffuser inlet; Pl ". 6: Look at the diffuser exit;

The device for the uniform distribution of a two-phase flow is arranged according to the embodiment according to FIG. 2 in the head region of a vertical Hooh-pressure tube bundle heat exchanger. Centrally in Deokel 1 of the apparatus is a vertical circular inlet channel 5, which corresponds in its diameter to that necessary for feeding the Zweiphasengemieohes pipeline outside the stationary apparatus. In this circular inlet channel 5 of the Komogenisator 6 is arranged. In the upper part of the homogenizer 6 there is a stepped upper nozzle 9, which reduces the flow cross section at its lower end to 30 % . The upper part of the stepped upper nozzle 9 narrows according to the exemplary embodiment with 10 ° and the lower part, which is 25 % of the total height of the upper nozzle 9, 45 ° to the axis of symmetry.

FIG. 1 t Pig. CVI Pig. 3: Pig. 4: Pig. 5:

2708 ί

About the height of the upper part of the upper nozzle 9 are distributed on the circumference gleiohmäßig four reohteokige Antidrallbleohe 8, which protrude with a depth of 0.25-Faohen the Durohmessers of the circular inlet channel 5 in this, angebraoht. In the transition region between the regions of the upper nozzle which are narrowing to different degrees, a horizontal groove 10 with an approximately semicircular cross-section is incorporated, the proportion of which at the cross-section of the circular inlet channel 5 being on the order of the plussed volume fraction of the flow.

Halfway up the lower part of the upper DUoe 9 is a Gindrehung 11 with semicircular Quersohnitt whose width oa. 1/5 of the width of the groove is 10, incorporated. Following the stepped upper nozzle 9, a conical transition piece 13 follows, whereby the diameter of the duro-flow channel is up to 70 % of the diameter of the circular inlet channel 5 at a height of the extension range of 0.3 of the diameter of the circular inlet channel 5 verr_ngert.

In konieohen transition piece 13 is a resistance body 12 is in the middle roughened, which is formed in its upper part against the Strömungeriohtung conical with rounded tip, and whose lower part is cylindrical and serrated at its lower blunt end. The largest diameter as well as the height of the resistor body 12 are according to the Ausführungsbeispiel the 0.5 Faohe Durohmessers of the circular inlet channel 5, the conical roof 12.1 and the ZylinderstUok 12.2 are hoohohohoh and the ZylinderstUck 12.2 of the resistor body 12 at the height of the lower end of the conical transition piece 13 begins. Since the cone-shaped roof 12.1 of the resistance body 12 is located inside the conical transition piece, the channel cross-section remains approximately constant in this region. The conical transition piece 13 is adjoined by a lower nozzle 14, which is made of thin bleoh and which, according

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The control orbit has a height of 0.6 ° the diameter of the circular inlet channel 5 and narrows at 15 ° to the axis of symmetry. At the outlet of the lower nozzle 14 are evenly distributed around the circumference 8 pairs of slots of 5 cm in height and 1 om distance incorporated. In the exemplary embodiment, every second narrow lobes of the sheet resulting from this is bent away by 25 * from the other nozzle contour to the outside

 At the end of the lower nozzle 14, the flow cross-section increases dramatically to the value of the circular inlet channel 5. At a distance of the diameter of the circular inlet channel 5 follows the lower nozzle 14, a rectifier 15. This is in the embodiment of six rectangular metal strips with a height of the 0th 5 times the diameter of the circular inlet channel 5. In each case, three sheets are at the same distance parallel to each other, while the other also at the same distance parallel to each other arranged sheets at right angles intersect the first-mentioned sheets, whereby the Kanalquersohnitt is segmented.

At a distance of 0.5 ° of the diameter of the circular inlet channel 5 from the rectifier 15, the flow cross-section begins to expand evenly to the tube mirror diameter. This expansion ratio is 1: 5 at an extension angle of 30 °. In this area, the concentric with each other arranged cones 16 existing diffuser 7 is attached. According to the exemplary embodiment, the diffuser 7 consists of five thin-walled cones 16 with increasing from the inside to the outside height, the outermost cone 16 limits the entire Brweiterungsbereich between the outlet of kreisför shaped inlet channel 5 and tube sheet 3 to the outside. Due to the concentric arrangement of the five cones 16, the flow cross-section is likewise subdivided into five diffuser channels 17. The innermost circular diffuser channel 17 is thereby bounded by the inner contour and the inlet and the outlet cross section of the innermost cone 16. The next

- 10 -

- ίο -

30

Outside Mufusorkanäle 17 are each bounded by an inner and an outer cone 16, the common entry heights of the cones 16 and the exit height of the respective inner cone 16.

By choosing the inlet diameter, the height, and the outwardly decreasing expansion angle of the cones 16 ensures that the ratio of exit to inlet cross-section of the outer diffuser channels 17 is smaller than the ratio of exit to inlet cross-section of the Tnnenkontur of each inner cone 16 limited inner flow channel.

In the exemplary embodiment, this is achieved by a geometric division according to the following table and associated FIG. 4:

Cone no.

Diffuser channel no.

FJ. K

16.1 0 2 D 0.65 D 1, 60 D 8 ° 8 ° 17.1 10 , 7 1 0 , 6 20 16.2 0 , 4 D 1, 40 D 1, 87 D 15 ° 7 ° 17.2 12 ,8th 1 2 3 16.3 0 , 6 D 2.24 D 2.13 D 21 ° 6 ° 17.3 15 3 1 3 , 9 16.4 0 ,8th D 3.14 D 2.40 D 26 " 5 ° 17.4 17 3 1 5 , 4 16.5 1 , 0 D 5.00 D 3.46 D 30 ° 4 ° 17.5 37 , 5

D d.

⁽ Wd

Diameter of the circular inlet channel Entry diameter of the cone

Exit diameter of the cone

Height of the cone

Extension angle of the cone to the axis of symmetry

Difference of extension angles of adjacent ones

Konen

Outlet to inlet cross section of the diffuser

sorkanala

Outlet to inlet cross-section of the next

inner cone (total more inward

Gtrömungskanal)

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-11 -

The second outermost cone 16 ends according to the exemplary embodiment at a distance of about 1.5 of the Durohmessers the circular inlet channel 5 above the provided with parallel tube bundle tubes k tube bottom. 3

 5

The mode of operation of the invention is as follows: Since a partially phaeenentmlsohte uneven two-phase flow sioh in the inflow to Kopfbereioh of stationary apparatus, this is before the surface of circular cross-section, which corresponds in the AusfUhrungsbeispiel the tube sheet to homogenize and low loss gleiohmäßig split on this. The uniform distribution of the two-phase flow over the cross section of the circular inlet channel serves the homogenizer.

Due to the anti-whirl plates in the upper area of the homogenizer, a possible, opposite to the uniform distribution of the gas / liquid flow swirl is reduced. Such an undesirable twisted two-phase flow may be e.g. B. arise through manifold, elbows and the like in the piping system in front of the apparatus. In the graduated upper nozzle, the two-phase mixture consisting of liquid and gaseous components is accelerated and directed towards the center of the channel. The horizontal circumferential groove causes a uniform circumferential distribution of the liquid components of the mixture, if an unequal distribution, z. B. in the form of a one-sided liquid or a non-uniform fluid film is present on the channel wall. At low fluid loads, this effect is the recess at half the height of the lower part of the upper nozzle

; i further strengthened. The inlet diameter of the conical transition piece is slightly larger than the outlet diameter of the upper nozzle, wherein the lower edge of the upper nozzle is formed in this region as a drip edge to guarantee a detachment of the liquid film from the wall guaranteed.

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Daa centrally steered and due to the groove of the recess and the action of the stepped upper DUse aohon partially homogenized mixture bounces against the conical Daoh of the resistor body and runs there or is further homogenized in the flow channel and subsequently in the region between the lower nozzle and ZylinderetUok the resistance body , Behind the resistance body forms an intense vortex area, as well as at the outlet of the lower nozzle. Within four fluidized areas there is an increased mixing of the liquid and gaseous components and thus the distribution of the mixture. This effect is further enhanced by the tines at the lower end of the resistor body. By draining the liquid film, a fine dispersion of the liquid components is achieved.

The rectifier arranged at the lower end of the homogenizer breaks down larger vortices and thus ensures uniform distribution of the finely dispersed two-phase mixture before entry into the diffuser. The homogenizer as a whole causes a substantial homogenization of the velocity profile over the cross section of the circular inlet channel with a simultaneously achieved homogeneous distribution of the liquid and gaseous components of the mixture. Compared to the known prior art, this effect is achieved over a very wide throughput and variation range in the composition of the two-phase Gemisohes. The effectiveness of the homogenizer is therefore independent of the flow rate resulting from throughput, properties and proportion of the liquid and gaseous mixture components and from the geometry of the Zufünrungsleitungen outside the apparatus in the inlet cross-section of the circular inlet channel. In the various Ströraungsforraen different elements of the homogenizer are particularly effective, for. B. the Antidrallbleohe with twisted two-phase flow and the groove in the stepped nozzle in connection with the recess at low or at the circumference uneven liquid sbeaufschlagung.

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Since in the inventive design of the homogenizer, the Duronmisohung and dispersion of the phases takes place substantially in the vortex field behind the resistor body and the lower nozzle, a lower Druokverlust is achieved over the prior art. The diffuser adjoining the homogenizer serves for the low-loss deceleration of the flow in the expanding flow channel between the outlet of the circular inlet channel and the surface of circular cross-section, to which it is to be distributed if the homogeneity of the homogeneous phase distribution of the mixture and of a velocity-compensated velocity profile are required. This is achieved by the geometric configuration of the concentric cone diffuser described in the exemplary embodiment. Since in this embodiment, the ratio of outlet to inlet cross-section of the outer diffuser channels is each Kleirer than the ratio of outlet to Eintrittsquer-, cut the limited by the inner contour of the respective inner cone Strömunj.skanales lies in the outlet cross-section of this inner channel a little slow speed in front. The increased exit velocity in each outer channel causes a radially outward suction directly at the end of the inner channel. On the inner surface of the outer boundary of diffuser channels easily lossy separation vortices can form. This negative effect is still promoted in two-phase flows with gaseous and liquid mixture components by the always forming liquid film on the channel wall. In the diffuser design according to the invention, this counteracts the outward suction effect. The formation of such separation vortices is practically prevented.

While common, the state of Techrik corresponding multi-diffusers with the same extension angle between the individual diffuser channels at the diffuser exit a convex

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Gesohwindigkeitsprof11, which would lead in the application considered to a lower loading of the fläohenmäßig crucial outer Rohrspiegelbereiohe causes the diffuser according to the invention at the outlet of the individual Diffusorkan ".le a radially outwardly slightly exaggerated Gesohwindigkeitsprofil, which is due to the increasing outward height of the individual DIffusorkanäle Immediately in front of the tubesheet is a uniform Gesohwindigkeitsprofil with homogeneous phase distribution.This ensures equal exposure of all tube bundles or the entire surface of a Katalysatorbettea achieved with homogeneous phase distribution, whereby a high heat exchange on the tube side or a high Stoffaustausoh is guaranteed.

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Claims (6)

2 7 O β 1 - 15 - claim 1. A device for homogeneous distribution of a gas-liquid mixture, which is fed through a vertical circular inlet channel zentrisoh in Kopfbereioh a stand the apparatus is on a Pläohe with circular cross-section, the device has in its upper part a narrowing the cross-section of the inlet channel and homogenizer homogenizer in the space extending between the homogenizer and the surface of circular cross-section, a diffuser consisting of a plurality of concentrically arranged cones, characterized in that in the upper area of the homogenizer (6) there is an antidrill plate (8) which is distributed uniformly on the circumference in the interior. the cross-section of the circular inlet channel (5) is arranged at the lower end on a 25 to 50 % reducing graduated upper nozzle (9) whose upper part is 10 to 20 * and whose lower part is 20 to 30 % of the total nozzle height, with 40 to 5 0 ° to Symmetrieachee constricted, wherein in the transition between the different narrowing DUsenbereiohen a horizontal radial circumferential groove (10) is approximately semi-circular cross-section, and in that following the upper nozzle (9) 'an expanding conical transition piece (13 ), wherein the flow cross section remains approximately constant due to a resistance body (12) arranged centrally in this region, and in that the resistance body (12) with a height of about 1/2 of the diameter of the durometer - 16 - - 16 - shaped inlet channel (5) consists of an upper conical Daoh (12.1) with a rounded tip and a lower Zylinderetüok (12.2), and in that at the level of the lower end of the conical roof (12.1) of the resistance body (12) to the conical transition piece ( 13) connects the flow cross member consisting of a lead jacket to the lower nozzle (14) narrowing to 0.4 to 0.6 degrees of the circular inlet channel (5), and that after the lower nozzle (14) again a sudden transverse broadening to the diameter of the circular inlet channel (5) and arranged at a distance of 1 to 2-faohen the Durohmessers of the circular inlet channel (5) to a parallel and sioh crossing Haltebleohen constructed rectifier (15) is arranged at the siohim space between the homogenizer (6) and the surface of circular cross-section of a consisting of up to five concentrically arranged relatively thin-walled cones (16) existing Dif fusor connects and between the thin-walled cones (16) radially extending thin-walled sheet metal webs (18) are arranged, wherein the widening angle of the two benaohbarten cones (16) formed diffuser channels (17) decrease from the inside to the outside, and that by choosing dos Entrtrittsdurohmessers the thin-walled cones of the outwardly increasing height of the individual cones (16), the ratio of exit to entry cross-section of each diffuser (17) is smaller than the ratio of the exit to inlet cross-section of the next inwardly adjacent cone (16), the exit cross-section of the outermost cone (16) ends at a distance of 0.1 to 0.3 times the diameter of the circular surface above the latter. 2. Device according to claim 1, characterized in that the Antidrallbleohe (8) are arranged in the upper region of the stepped upper nozzle (9), above the groove (10) ends and have approximately reohteokige shape, the Antidrallbleohe (8) as the 0.1 to 0.3 times the diameter of the circular inlet channel (5) protrude into this. - 17 - - 17 - 3. Device naoh Anspruoh 1, daduroh characterized in that in above. Half a height of the lower part of the upper nozzle (9) has a recess (11) approximately semicircular cross-section whose width is about 1/5 of the width of the groove (10) is incorporated. 4. Device according to claim 1, daduroh gekc inzeiohnet that the resistance body (12) is formed evenly distributed jagged at its lower end over the entire circumference, wherein the size of the division is 3 to 10 mm. 5. Device naoh Anspruoh 1, characterized in that the lower nozzle (14) narrows Bioh with a V / inkel of 10 to 30 ° relative to the axis of symmetry, wherein the total height of the lower nozzle 'Ί4) about the 1/2 Faohe the diameter of the circular inlet channel (5) and this is provided at its lower edge evenly on the circumference with thin Schiit- zen and every second sheet metal tabs between the slots up to 30 ° with respect to the rest DUsenkontur naohaußen is bent. 6. Device according to claim 1, daduroh in that the inlet diameter of the conical transition piece (13) is dimensioned slightly larger than the outlet diameter of the upper nozzle (9), wherein this is performed as a drip edge. For this d sides drawings