US2175360A - Rectifying apparatus - Google Patents

Description

Oct. 10, 1939. 'p PEFF .y y2,175,360v

RECTIFYING APPARATUS Filed March 22, 1938 i IEIIIIIH 72 ZeZEfE j',

ATTORNEY.

Patented Oct. 10, 1939 UNITED STATES PATENT OFFICE arsso RECTIFYING APPARATUS Peter PeI, West Orange, N. J. Application March 22, 1938, Serial No. 197,427

claims. (ci. zel-114) I This invention relates to improvements in rec. tifying apparatus; and the invention has reference, more particularly, to improvements in rectifying columns adapted to be employed, among 5 other uses, for the separation of the various gaseous constituents of atmospheric gas mixtures, such e. g. as oxygen, nitrogen, argon and neon gases.

'Ihis invention has for an object to provide a novel construction and relative arrangement of bubble cap trays for rectifying columns; and the invention has for a further object to provide a novel construction of bubble cap means per se, for use in connection with such trays.

l5 Other objects of this invention, not at this time more particularly enumerated, will be understood from the following detailed description of the same.

An illustrative embodiment of this invention is shown in the accompanying drawing, in which:

Fig. 1 is a vertical longitudinal sectional view of a plurality of bubble cap trays according to this invention, and as arranged in operative assembled relation; Fig. 2 is a plan view of one of said trays; Fig. 3 is a side elevation of a novel bubble cap structure with which the trays are provided, the same being drawn on a scale greatly in excess of actual' size; Fig. 4 is a vertical longitudinal sectional view of the novel bubble cap structure;

and Fig. 5 is .a horizontal sectional view thereof,

taken on line 5-5 in Fig. ll.

Similar characters of reference are employed in the above described views, to indicate corresponding parts.

The novel rectifying apparatus according to this invention, comprises a multiplicity of horizontal trays superimposed one upon another to form a column, and so constructed and related that condensed liquid or reux, produced in the operation of the column, will overow from the trays so as to descend through the column from one tray to another'. Each tray is provided with a multiplicity of bubble cap structures through which gases may rise in ascending the column from tray to tray.

In preferred form each tray comprises a peripheral and preferably annular side wall member I0 of suitable height to provide a desired gas chamber capacity between adjacent assembled trays. At one end, preferably the upper end, a marginal portion of said side wall member I0 is laterally offset to provide a receiving collar Il and seat I2 to telescopically receive the adjoining end of a superimposed tray, whereby the trays r forming the column are successively connected ywith the next tray below.

A the external of the line of the dam I6 is desirably 'or less.

one with another. suitably secured to the side wall member I0, intermediate the upper and vlower margins thereof and so as to extend horlzontally across the area bounded thereby, is a tray bottom plate I3. The tray bottom plate I3 5 is cut away at one side along a chord or line intersecting the line of the side wall member I0 to form a spillway space I4 for communication Disposed to extend vertically through this space I4 is a conduit l0 member I5 which is shaped in cross-section to conform thereto. The upper marginal portion of the inner vertical wall member of said conduit member I5, contiguous to the margin of the tray bottom plate I3, projects upwardly abovel the level of the latter to thereby form a dam IB of a height predetermined to correspond to a predetermined depth of reflux desired to be maintained in the tray. The extent of downward projection of the lower end of vsaid conduit 20 member I5'is such, that its lower extremity will dipbelow the reflux level in the tray next below, thereby providing a liquid seal against passage of gases through said conduit member I5 from 1 the gas chamber I'I intermediate said adjacent 25 trays. When assembling the trays one upon another, the conduit members I5 of alternate successive trays are oppositely disposed so that proper downward ow of reflux will be maintained from tray to tray. In order to assure a 3 properly sustained flow movement of reflux liquid as uniformly and widely distributed over the entire area of the tray bottom plate as possible,

considerably in excess of the radius of the tray, 3 and e. g. is preferably of an extent of about one and one-half times the radius of the tray more Mounted in connection with each tray bottom plate vI3 are a multiplicity of bubble cap devices 4( of novel construction. Each bubblecap device comprises a hollow cap shell IB of desired crosssectional shape, but preferably circular whereby said shell isl cylindrical in form. Said cap shell I8 is open at its lower end, but is provided with a 4. top end wall I9 to close its upper end. Integrally formed with said top end wall I9 is a downwardly-open hollow or recessed-head 20 of reduced diameter. Said head 20 is aligned with the vertical axis of the shell I8 so as to be concentric to 5 the latter. Extending axially upward through the interior of said shell I8 is a cylindrical riser member or tubel 2l, the upper end of which is telescopically received into the internal recess of said head 20 so as to befclosed thereby. Said 5 riser member 2| and shell I8 may be secured together in the described assembled relation in any suitable manner, as e. g. by interlocking tits 22 punched or struck out from the contiguous side walls of said riser member 2| and head 20. The lower open end of the riser member 2| projects beyond the lower end of the shell IB. To assemble the bubble cap device in operative connection with and in upstanding relation to a tray bottom plate I3, the projecting lower open end portion of the riser member 2| is inserted downwardly through a correspondingly sized opening 23 provided in the tray bottom plate until the bottom margin of the cap shell I8 abuts and is stopped against the upper surface of said tray bottom plate, whereupon the bottom marginal portion of said riser member 2| is laterally and outwardly curled or flared over the under side of said tray bottom plate to form a retaining lip or bead 24 for anchoring the bubble cap device to the tray bottom plate. When the bubble cap device is thus assembled and mounted, the lower open end of the riser member 2| will communicate with the gas chamber I1 beneath the tray bottom plate. It willbe obvious that the riser member 2|, as assembled with the cap shell I8 in the manner above described, will be immovably connected to the latter in concentric relation thereto so as to provide a uniform annular gas passage 25 between the cap shell and riser member walls.

Formed in the Wall of the riser member 2| immediately below the top end wall I9 of the cap shell I8 is a circumferential row of gas venting ports 26 which open outwardly from the riser member interior into the annular gas passage 25 intermediate the riser member and cap shell. As thus positioned, these ports 25 are located above the level of reflux liquid contained within the tray. Preferably said ports 26 are in the form of elongated closely spaced narrow slots.

Formed in the wall of the cap shell I8, adjacent to the bottom end thereof, is a circumferential row of gas escape ports 27 which open outwardly from the annular gas passage 25 within the cap shell. These gas escape ports 27 are located below the level of reiiux liquid contained within the tray, and are thus submerged in said liquid. Said gas escape ports 21 are also preferably in the form of elongated closely spaced narrow slots, and terminate at their upper ends in inverted V-shaped or pointed end portions 28. The V-shaped or pointed formation of said end portions 28 of the gas escape ports 21 facilitate the breaking away and upward night through the reiiux liquid of the bubbles of gas discharged through said ports. Preferably the length or height of the slot-like gas venting ports 2E'and the gas escape ports 27.

should approximate one-half the internal diameter of the riser member 2|.

For best results in the operation of the column for the rectication of atmospheric gas mixtures, a proper flow of velocity reux liquid across the tray is facilitated by assembling the bubble cap devices to the tray bottom plates in staggered rows and in such spaced relation one to another that the clearance space therebetween approximates about one-quarter of the diameter of the caps.

The novel bubble cap structure, as above described is of high efliciency by reason of the fact that it functions to thoroughly break up the ascending gaseous vapors in such manner as to assure intimate contact of :finely divided bubbles thereof with the liquid :dowing across the trays.

By reason of the provision of the plurality of narrow gas venting ports 26 at the top of the riser 2|, gaseous vapor, as they rise from a gas chamber I1 below the tray and pass upwardly through the riser, are `deflected at the top of the riser through said venting ports 26 into the gas passage 25 of the cap shell. Such movement of the gaseous vapors through said venting ports 26 not only provides an initial breaking up of the vapors, but also tends to precipitate or separate from the vapors any droplets of condensate carried along therewith. As the initially broken up gaseous vapor enters and descends within the gas passage 25 of the cap shell, it is thereupon caused to next pass through the escape ports 27, wherebyit is further broken up-and brought into intimate contact with the reflux liquid flowing across the tray, the iine bubbles, as discharged rising through said reux and discharging into the gas chamber II above the tray.

Owing to the interfitting relation of the riser member 2| and cap shell I8, a symmetrical, strong and durable bubble cap structure is provided, as well as onewhich may, by a simple mechanical operation, be strongly and rigidly anchored to the tray bottom, so as to be firmly held against displacement from operative assembled relation to the latter.

Having now described my invention, I claim:

1. In a bubble cap tray for re'ctifying columns, a bubble cap structure therefor comprising, a hollow cap shell closedV at its upper end, a riser member of reduced diameter extending axially of said cap shell and having a portion of its upper end extending through the top end wall of said cap shell and secured thereto thus providing an intermediate gas passage within said cap shell, the lower end portion of said riser member pro.- jecting downwardly through the bottom end of said cap shell and being adapted to extend through a receiving opening provided in the tray bottom therefor and secured to thus anchor the bubble cap structure to the tray, said riser member having a plurality of gas vent ports opening into the upper end of said gas passage, and said cap shell having a plurality of gas escape ports opening out of the lower end of said gas passage.

2. In a bubble cap tray for rectifying columns, a bubble cap structure therefor comprising, a hollow cap shell closed at its upper end and provided with at such end with a centrally located upwardly oiset recessed head of reduced diameter, a riser tube having its upper end tted into and secured to said recessed head to extend axially downward through the interior of said cap shell, thereby forming an intermediate gas passage, the lower end portion of said riser tube projecting downwardly beyond the bottom end of said cap shell and being adapted to extend through a receiving opening provided in the tray bottom therefor and secured to thus anchor the bubble cap structure to the tra'y, said riser tube having a plurality of gas vent ports in its upper end portion for communicatior with said intermediate gas passage, and said cap shell having a plurality of gas escape ports in its lower end portion to open into the reux liquid contained in the tray in use.

4. In a bubble cap structure as dened in claim 2, wherein said gas ventA ports 'and said gas escape ports each comprise rows o! vertically extending slot-like openings, the length of said slots approximating about one-half the diameter of the riser tube, and wherein the slots forming said gas escape ports terminate at their upper ends in inverted v-shaped extremities.

5. In a bubble cap structure as defined in claim 2, wherein the gas escape ports of said cap shell comprise a row of vertically extending slot-like openings, the length of said openings approximating about one-half the reflux depth capacity 5 of the tray.

PETER PEFF.

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