US3105105A

US3105105A - Contact plate structure for use in a rectifying or contacting column

Info

Publication number: US3105105A
Application number: US6914A
Authority: US
Inventors: Kittel Walter
Original assignee: Individual
Current assignee: Individual
Priority date: 1952-03-07
Filing date: 1960-02-05
Publication date: 1963-09-24
Anticipated expiration: 1980-09-24
Also published as: US3039750A; US3156746A

Description

Sept. 24, 1963 w. KITTEL CONTACT PLATE STRUCTURE FOR USE IN A RECTIFYING OR CONTACTING comm 2 sheets-sheet 1 Filed Feb. 5. 1960 2 3, .Z v Z i M. T 2 8 I. 8 a 9 v 7 ,O z 5 r 9 9 9 0 a 0 0 I. n 2 m r5 9 5 n All il 2 F 6 MW INVENTOR MTERAITTEZ ATTORNEYS Sept. 24, 1963 w. KITTEL CONTACT PLATE STRUCTURE FOR USE IN A RECTIFYING OR CONTACTING COLUMN 2 Sheets-Sheet 2 Filed Feb. 5, 1960 INVENTOR 14 4475? An'rez.

m G O Q; QHQQQ f mvflg Q Q ATTORNEYS United States Patent 3,165,105 CONTACT PLATE STRUCTURE FOR USE TN A RECTTFYTNG 6R CONTACTTNG CGLUMN Walter Kittei, Garteugasse 12, Grnunden, Austria Filed Feb. 5, 1969, Ser. No. 6,914 Claims priority, application Switzerland Mar. 7, 1952 8 'Ciaims. {(Jl. 261--79} This application is a continuation-in-part application of my co-pending patent application Serial N0. 598,713 filed on July 18, 1956, for A Contact Plate Structure for Use in a Rectifying or Contacting Column which has been abandoned in favor of this application. The prior application is in turn a continuation-in-part of application Serial No. 340,583 filed March 5, 1953, now abandoned.

This invention relates to rectifying or contacting columns wherein a liquid and a gaseous medium are brought into intimate contact, and more particularly to a contact plate structure for use in rectifying or contacting columns.

An object of the invention is to provide a contact plate structure for use in a rectifying or contacting column, by means of which the period of contact between the media passing in opposite directions through the column may be extended on each contact plate structure for a long time, and by means of which comparatively large time intervals may be obtained between the periods of contacts of a medium on successive contact plates.

Another object of the invention is to provide a contact plate structure for use in a rectifying or contacting column, by means of which a thorough circulation of the liquid is obtained.

A further object of the invention is generally to improve on the construction of contact plate structures as now customarily made.

A still further object of the invention is to provide for rectifying or contacting columns comprising a plurality of contact plate units in a spaceand material-saving arrangement.

Other objects and structural details of the invention will be apparent from the following description when read in conjunction with the accompanying drawings forming part of this specification, wherein:

FIG. 1 is a vertical sectional view taken on line 1-1 of FIG. 2, of a portion of a rectifying or contacting column having contact plate structures according to the invention, wherein in each contact plate structure the gases or vapors are introduced from the circumferences,

FIG. 2 is a sectional view of the column shown in FIG. 1, taken on line 22 of FIG. 1,

FIG. 3 is a vertical sectional view of a contact plate of the column shown in FIG. 2, taken on line 33 of FIG.

FIG. 4 is a vertical sectional view of a portion of a different embodiment of a plate structure unit mounted a column, taken on line 44 of FIGS. 5 and 7,

FIG. 5 is a sectional view along line 55 of FIG. 4,

FIG. 6 is a fragmentary front View of a column comprising several contact plate structure units of the kind shown in FIGS. 4 and 5, the enclosure wall of the column being partially broken 'away, and

FIG. 7 is a top view of the column shown in FIG. 6.

Referring now to FIGS. 1 and 2, 29 generally indicates a rectifying or contacting column having a series of contact plates or collecting trays 1, arranged in different planes above each other. Each contact plate or collecting tray :1 has an upwardly extending flange 22. The collecti g trays 1 are mounted in a manner known per so (not shown in FlGS. 1 and 2), one above the other, within a jacket 6 0f the column 24 Each collecting tray :1 has a central opening receiving an outlet tube or down- 3-,lh5dfl-5- ?atented Sept. 24, 1963 corner 3. The upper edge of the downcorner 3 being above the bottom of the tray 1 determines the height of the layer of liquid on the tray 1. The d'owncomer 3 extending downwardly from the tray 1 terminates above the bottom of a dip cup 4. A radially and dow-nwardly directed cone-like member 5 extends from the edge of the dip cup 4 to a point above the next lower collecting tray 1. Liquid from the upper collecting tray 1 may be discharged .by the downcorner 3 to the next lower collecting tray 1 in the direction of the arrows A.

The annular cross-section between the flange 22 of the tray 1 and the jacket 6 serving as passage for the ascending gaseous medium flowing in the direction of the arrows B is covered by a guide ring 2 having a downwardly extending cylindrical wall or flange 24. Said ring 2 is rigidly and tightly connected with the jacket 6 and said flange 24 projects into the collecting tray 1 having the upwardly extending flange 22. The lower edge of the flange 24- of the ring 2 is in a plane somewhat below the plane of the upper edge of the flange 22. Thus, the path of the ascending gaseous medium is guided by the ring 2 into the collecting tray 1 as indicated by the arrows B.

A substantially honizontal perforated plate or plates 7 having a plurality of inclined slots 26 (see FIGS. 1, 2 and 3) for the upward passage of gaseous medium from the space below said plate or plates 7 in the direction of the arrows B is connected to the lower edge of said downward flange 24 of the deflecting ring 2. As best shown in FIG. 2, said plate or plates 7 are divided into six sectors or

zones

28a, 28b, 28c, 28d, 28c, 28 the slots 26 in each zone or sector being parallel to one of the radial sides of the sector. The construction of the inclined slots may be best seen from FIG. 3. During the operation of the column, the plate 7 being above the bottom of the collecting tray 1 and below the upper edge of the associated downcorner 3- is submerged in the layer of the liquid held by the respective collecting tray 1. The slots 26 of said perforated plate 7 are so directed that the streams of gaseous medium passing through said slots have radial and tangential components.

The center zone of the plate 7 has an aperture 30 and the marginal zone of the plate 7 has a plurality of openings 32, one in each sector 28a, 28b for the passage of liquid circulating around said perforated plate 7.

The condition of flow resulting from above described structural design of the column is indicated in FIGS. 1 and 2 by arrows. Arrows in full lines refer to the flow of the liquid, while arrows in dash lines refer to the flow of the gaseous medium. The arrows C (FIG. 2), for example, indicate the spiral-like path forced upon the liquid above the submerged plate 7 by the gaseous medium passing through the slots 26. The liquid thrown outwardly from the center of the plate 7 in spiral-like paths C passes downwardly towards the bottom of the tray 1 in the following manner: In the marginal zone of the plate 7 the effect of the centrifugal force acting on the liquid is reduced, so that at least a portion of the liquid may pass like rain through the slots of the plate 7 towards the bottom of the tray 1; furthermore, especially if the liquid contains fatty substances caused by chemical reactions, the liquid passes downwardly through the apertures 32 arranged near the circumference of the plate 7. The liquid is then caused to recirculate in the space below the plate 7, towards the center, and is upwardly led, through the aperture 31 formed in the center zone to the space above the plate 7 once again. Thus, the liquid is repeatedly circulated in the direction of the arrows D around the perforated plate 7 between the space above and below the latter under the influence of the gaseous medium passing through the slots 26 of the plate 7.

W .en the layer of liquid exceeds the level determined by the upper edge of the downcomer 3, liquid is discharged through the latter towards the next lower colecting tray 1.

A shielding ring it} connected to the plate 7 projects downwardly therefrom surrounding the downcomer 3 so as to form the aperture 3% mentioned above. Each opening 32 communicates with a discharge tube 8. The upper ends ,of the discharge tubes 8 are flush with the upper surface of the plate 7. Ring 1% and said tubes 8 act as shielding means so as to deflect the fiow of gaseous medium for preventing a passage of said gaseous medium from the space below said plate 7 through said openings 3% and 32, respectively.

Although, as mentioned above, the efiect of the centrifugal force on the liquid, especially in columns of great diameter, is considerably reduced in the marginal zone owing to the substantial decrease in the angular speed in dependence on the increase in the radius, so

that the liquid may be returned into the space below the perforated plate 7, it may be desirable, especially in columns of small diameter, to provide for auxiliary guiding means assisting in the return of the liquid. For example, as shown in the drawings, guiding blades 9 directed radially inwardly and inclined relative to the horizontal plane may be arranged on the cylindrical portion 24 of the deflecting ring 2 near to the plate 7 and immediately behind the discharge openings 32.

As may be readily gathered from PEG. 1, the supply and the discharge of the liquid may be carried out in a simple manner as the liquid may be led to the center zone of the plate 7 surrounding the center aperture 30 by means of the umbrella-like conical member 5.

Or" course, the arrangement and the orientation of the slots 26 in the plate 7 causing the rotation of the liquid may be modified in many ways without eifecting fundamental changes in the principles of operation described above. It is a feature of the inventive arrangement that in accordance with the predetermined submersion of the plate 7 the layer of the liquid rotated by the tangential introduction of the gaseous medium or vapors and the centrifugal action caused thereby moves from the center towards the margin along the plate 7 directing the path of the gaseous medium or vapors by means of its slots 26, and that the movement of the liquid may be accelerated or decelerated radially by a corresponding orientation of the individual slots.

FIGURES 4 and illustrate a modified embodiment of the inventive plate construction, wherein the conelike deflecting members 5 of the dip cup means 4, as shown in FIGS. 1 and 2, have been replaced by a cylindrical structure generally referred to by reference numeral 105, to be explained more fully below.

The general construction of the embodiment of FIGS. 4 and 5 is otherwise similar to that of FIGS. 1 and 2. A column generally indicated by 120' comprises a series of superimposed contact plates or collecting trays 101 having upwardly extending flanges 122 and being mounted within a column jacket 1%. Downcorners 10-3 are centrally arranged, and extend downwardly to terminate within the space defined by a dip cup 164 which in turn is an integral part of the cylindrical structure 1&5 previously referred to.

The cylindrical structure 1'55 comprises a solid horizontally extending top plate portion 158 flush with the top plane of the dip cup 134 and a cylinder 159' proper which extends down to and is supported by a deflecting ring 1&2 above the next lower plate and having a flange 124-. The cylinder 159' is made from expanded metal so as to permit for communication between the space defined by the cylinder 159 on the one hand and the space between said cylinder and the jacket 1%.

The openings thus formed in the wall of the cylinder 159 are in the shape of slots 159:: which have a generally tangential direction similar to that of slots 26 in FIG. 3, with respect to the peripheral surface of said cylinder. Advantageously, this tangential direction should be such as to invert the sense of rotation imparted to the gaseous medium by e. submerged perforated plate, such as M57, as will be explained more in detail hereinafter.

In the embodiment of FIGS. 1 and 2, the upper edge of the downwardly extending flange 24 is flush with the plane of the ring 2. In the present embodiment, however, the flange 124 projects slightly upwardly above the plane of ring 102.

The structure of the plates 7, with their slotted sectors as illustrated in FIGS. 1 and 2, finds its counterpart in the embodiment of FIGS. 4 and 5 in the perfonated plates 397. As these elements have been described in detail in connection with FIGS. 1 and 2, no further explanation is required in this respect.

As can be appreciated from the inspection of FIG. 5, the sense of rotation imparted, by the plate 107, to the gaseous medium is anticlockwise as viewed in FIG. 5, whereas the openings 15% formed in the wall of the cylinder 15? are substantially tangentially directed with respect to the periphery thereof, but in a sense which is such as to counteract the generally rotary motion imparted to the rising gases. This reversal of the generally rotary movement of the gaseous medium as it passes from the inside to the outside of the cylinder 159 is such as to greatly facilitate the precipitation and separation of droplets of liquid possibly entrained by the gaseous stream rising from the collecting tray ltil.

The provision of the cylindrical structure which extends across a major portion of the width of the column assures excellent contact between gas and liquid. In the embodiment of FIGS. 1 and 2, the liquid drops from the centrally arranged cone members 5 onto the central portion of the next lower plate structure without substantial contact with the rising gases during the descent. By replacing cone members 5 by the wide cylindrical structure 105, a more intimate and eflicient contact between the ascending gases and the descending liquid is obtained, as the liquid is forced to flow from plate to plate within the restricted space between the cylinders 159 and the outer. jacket 1% which space is traversed by the rising gases. The path of the rising gases is indicated by the dotted arrows, while the path of the liquid is shown in full line arrows. The intimate contact between the two fluids is readily apparent. It will be noted that the liquid upon impinging on the deflecting rings 102 will flow through the openings 159a in the expanded metal cylinders 15% into the space defined by the plates 16-7. The flow of the liquid is thus somewhat impeded and a kind of liquid seal is created which facilitates the desired gas-liquid contact.

Other elements of the modified embodiment shown in FIGS. 4 and 5, for instance, discharge tubes 198 and openings 132 in the plates 1il7, are similar to their respec tive countenpa-rts 8 and 32 of the first embodiment.

The invention also provides for a column construction wherein a plurality of plate structure units are arranged and mounted within a single column casing. This novel concept is illustrated by way of example in FIGS. 6 and 7. It will be noted that the space of :a cylindrical outer jacket or casing 269 of the colunm is subdivided into four compartments A, B, C and D by walls 196, and that several plate units are arranged in rows in the respective compartments. Of course, a larger or smaller number of compartments and/or units could be provided. This construction saves a considerable amount of space and material and is to be recommended for use in largecapacity plants. The embodiment of FIGS. 4 and 5 has been illustrated as one of the units of FIGS. 6 and 7 and the jacket 1% of FIGS. 4 and 5 thus corresponds to a pair of the walls 1&5 in FTGS. 6 and 7.

It will be realized that the arrangement of several units within one column casing has the additional advantage r that the supplying system for the gases and liquids can be centralized and simplified as the gases will be free to fiow between and around the individual units.

Contact plate structures as described above have a large volume of liquid and at the same time a small resistance to fiow so that they are very well suitable for processes wherein the liquid shall remain as long as possible in a collecting tray, inasmuch as the volume of liquid in the collecting tray may be varied within any desired limits by selecting a suitable distance between the bottom of the collecting tray and the submerged perforated plate.

Therefore the devices described above may also be used for absorption processes with a single contact of liquid with a gaseous medium or vapors, as is the case, for example, in the NH absorption by sulfuric acid; in such a case, the collecting tray is replaced by the container itself while the necessary level of the liquid is maintained.

I have'described preferred embodiments of my invention, but it is understood that this disclosure is for the purpose of illustration, and that various changes in shape and proportion, as well as the substitution of equivalent elements for those herein shown and described may be made without departing from the spirit and scope of the invention as set forth in the appended claims.

What I claim is:

1. In a rectifying or contacting column wherein a liquid and a gaseous medium are brought into contact, a contact plate structure comprising in combination: a collecting tray capable of holding a layer of said liquid, downcomer means centrally disposed relative to said tray for discharging said liquid therefrom, said downcomer means communicating with said tray at a predetermined evel about the bottom of said tray whereby the height of said layer is determined, a substantially horizontal perforated plate having a center zone and a plurality of slots for the upward passage of said gaseous medium from the space below said plate, said downcomer means being in the shape of a tube located in said center zone, a device above the tray and extending into said tray for guiding the flow of said gaseous medium into said space below the plate, said plate being spaced from the bottom of the tray and arranged at a predetermined level below the communicating level of the downcomer means whereby said plate may be submerged in a layer of liquid in said collecting tray, said slots being so directed that the streams of said gaseous medium passing through said slots have a substantial component tangential with respect to circles about said center zone, means for circulating said liquid around said plate between the spaces above and below said plate under the influence of said gaseous medium passing through said slots, said circulating means including, in addition to said slots, liquid openings only in said center zone around said downcomer means and at a marginal zone of said plate, said openings in the center zone comprising an annular slot surrounding said tube, and shielding means extending downwardly from said plate adjacent all of said openings to deflect said streams of the gaseous medium to prevent the passage of the gaseous medium from the space below the plate through said openings, said shielding means of said center zone being in the shape of a downwardly extending ring spaced from and surrounding said tube.

2. In a rectifying or contacting column as claimed in claim 1, wherein the upper end of said shielding means is flush with the upper surface of said plate.

3. In a rectifying or contacting column as claimed in claim 1 wherein said openings in the marginal zone are uniformly spaced around the periphery of said plate, and said shielding means of the marginal zone is in the shape of tubes extending downwardly from said openmgs.

4. In a rectifying or contacting column as claimed in claim 1, further comprising guiding means above said plate and near said marginal zone adjacent said openings for deflecting the flow of said liquid, said guiding means being directed radially inwardly and being inclned relative to the horizontal plane.

5. In a rectifying or contacting column as claimed in claim 1, wherein said guiding device extends into said tray substantially at the margin thereof for causing a flow of said gaseous medium from said margin towards the center of said tray for passage through said center zone openings.

6. In a rectifying or contacting column as claimed in claim '1, wherein said guiding device has the shape of a deflecting ring having a downwardly extending flange at the inner side, said ring being in a plane at a predetermined distance above the upper edge of said tray, and said flange extending into said tray near the margin thereof at least to the level of said plate.

7. In a rectifying or contact column according to claim 1, wherein additional plate structures are arranged successively beneath said first named plate structure to form a unit having a longitudinal axis, saidplate structures, further comprising a dip cup arranged below said downcomer means, the lower end of said downcomer means terminating within the space defined by said dip cup, and guiding means adjoining the upper edge of said dip cup for guiding said liquid downwardly toward thenext lower plate structure beyond said center zone openings, said guiding means comprising a horizontally extending plate member and a cylindrical hollow member leading downwardly to the next lower plate structure, the walls of said hollow member having generally tangential openings for said passage of gaseous medium.

8. In a rectifying or contact column according to claim 7, comprising a plurality of said units, the longitudinal axes of said units being both parallel and adjacent to each other.

References Cited in the file of this patent UNITED STATES PATENTS 1,894,744 Haw-ley Jan. 17, 1933 1,983,762 Kotzebue Dec. 11, 1934 2,189,206 Grifiin Feb. 6, 1940 FOREIGN PATENTS 497,599 Belgium Sept. 15, 1950 (Corresponding Br. 682,721, Nov. 12, 1952.) 518,215 Belgium Mar. 31, 1953 869,527 France Nov. 7, 1941 OTHER REFERENCES Ser. No. 369,478, Stock (A.P.C.), published May 25, 1943.

Claims

1. IN A RECTIFYING OR CONTACTING COLUMN WHEREIN A LIQUID AND A GASEOUS MEDIUM ARE BROUGHT INTO CONTACT, A CONTACT PLATE STRUCTURE COMPRISING IN COMBINATION: A COLLECTING TRAY CAPABLE OF HOLDING A LAYER OF SAID LIQUID, DOWNCOMER MEANS CENTRALLY DISPOSED RELATIVE TO SAID TRAY FOR DISCHARGING SAID LIQUID THEREFROM, SAID DOWNCOMER MEANS COMMUNICATING WITH SAID TRAY AT A PREDETERMINED LEVEL ABOUT THE BOTTOM OF SAID TRAY WHEREBY THE HEIGHT OF SAID LAYER IS DETERMINED, A SUBSTANTIALLY HORIZONTAL PERFORATED PLATE HAVING A CENTER ZONE AND A PLURALITY OF SLOTS FOR THE UPWARD PASSAGE OF SAID GASEOUS MEDIUM FROM THE SPACE BELOW SAID PLATE, SAID DOWNCOMER MEANS BEING IN THE SHAPE OF A TUBE LOCATED IN SAID CENTER ZONE, A DEVICE ABOVE THE TRAY AND EXTENDING INTO SAID TRAY FOR GUIDING THE FLOW OF SAID GASEOUS MEDIUM INTO SAID SPACE BELOW THE PLATE, SAID PLATE BEING SPACED FROM THE BOTTOM OF THE TRAY AND ARRANGED AT A PREDETERMINED LEVEL BELOW THE COMMUNICATING LEVEL OF THE DOWNCOMER MEANS WHEREBY SAID PLATE MAY BE SUBMERGED IN A LAYER OF LIQUID IN SAID COLLECTING TRAY, SAID SLOTS BEING SO DIRECTED THAT THE STREAMS OF SAID GASEOUS MEDIUM PASSING THROUGH SAID SLOTS HAVE A SUBSTANTIAL COMPONENT TANGENTIAL WITH RESPECT TO CIRCLES ABOUT SAID CENTER ZONE, MEANS FOR CIRCULATING SAID LIQUUID AROUND SAID PLATE BETWEEN THE SPACES ABOVE AND BELOW