US2376341A

US2376341A - Apparatus for liquid contact for fractionating, etc.

Info

Publication number: US2376341A
Application number: US431520A
Authority: US
Inventors: Robert E Burk; Thomas J Walsh
Original assignee: Standard Oil Co
Current assignee: Standard Oil Co
Priority date: 1942-02-19
Filing date: 1942-02-19
Publication date: 1945-05-22
Anticipated expiration: 1962-05-22

Description

ETC

` May 22, 1945. R. E. BURK ETAL APPARATUS FOR LIQUID CONTACT FOR FRACTIONATING,

PLI 'E8 l5 1 1- Filed Feb. 19, 1942 INVENTORS gBERTEA BURK and n I l va por passage reflux To condenser vOMAS J. WALSH ATTORNEYS 5v Patented May 22, 1945 APPARATUS FOR LIQUID CONTACT FOR. FRACTIONATING, ETC.

Robert E. Burk, Cleveland Heights, and Thomas J. Walsh, Cleveland, Ohio, assignors to The Standard Oil Company, Cleveland. Ohio, a corporation of Ohio Application February 19, 1942, Serial No. 431,520

6 Claims.

In apparatus for contacting liquid with vapor or gas, as in fractional distillation and other contact operations. an arrangement of the liquid in very thin vertical films with which the gasiform moleculesl'may contact in counter current flow has shown particular advantages over the usual forms of apparatus in which the liquid is arranged in pools on trays through which the gasiform molecules may rise in bubble form. The mechanical dimculties in adequate support of closely enough spaced surfaces for the liquid have militated against realization of the highest efficiency theoretically possible. 'Very thin sheet metal has been necessary in order to vprovide the largest amount of liquid surface with the least bulking loss of space, but this has necessitated the interposition of spacer elements and on some constructions dents in the sheet metal to prevent misplacement of the sheet metal into contact and corresponding obliteration of the proper spaces. 'I'hese spacer elements have interfered with even liquid flow in the films and have introduced disturbing eddy currents in the vapor flow, and the efllciency has been lessened. In accordance with the present invention, a construction is involved which provides particularly free iiow for liquid lms and for vapor, and which may be in standardized form or units allowing application on large or small scale as desired in any instance. Other objects and advantages will appear from the description following.

To the accomplis ent of the foregoing and related ends, the inve tion, then, comprises the features hereinafter fully described, and particularly pointed out in the claims. the following description and the annexed drawing setting forth in detail certain illustrative embodiments of the invention, these being indicative however. of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawing- Flg. 1 is a vertical sectional view, partly broken, showing an embodiment `of the invention; Fig. 2 is a transverse sectional view taken on a plane substantially indicated byline II--II, Fig. 1; Fig. 3 is a similar view taken on a plane substantially indicated by line III-III, Fig. l; Fig. 4 is a perspective view showing a modiiied form of liquid feeder; and Figs. 5 and 6 are fragmentary transverse and vertical sectional views of plate details. The construction involves in general, a heuslng 2, with an inlet connection 3 below, and an outlet connection l above, and having a plurality of closely spaced thin plates 5 posi tioned at their lateral edges and operi at the top and bottom so as to allow vapor or gas to flow freely, while liquid flows downwardly in thin illms on the surfaces, and at the top liquid feeder means is arranged. I'he plates or sheets 5 are of suitable material, usually metal, in view of the liquids, etc., to be treated., and ordinarily, as with non-corrosive liquids and gases the sheets may be a. metal such as sheet steel. iron, copper, brass, zinc, etc. With liquids and gases which might cause corrosion, stainless steel, high chromium steel, nickel, monel, etc., may be employed. The sheets uniformly plain or iiat throughout are assembled into a unit or co-related structure between carrier plates 6, so as to be closely spaced to allow the passage of liquid iilms and gases as afore-indicated. They may be joined at their edges to the carrier plates by suitable means, such as soldering, welding, etc., but we prefer to avoid such fastening in so far as possible by special formingv of the sheets. For example, flanges S may be formed on the lateral edges of the sheets so that when apposed together the flanges provide the spacing, Fig. 5. Not all plates will then need to be fastened, as the plates may rest on narrow ledges C at the bottom of carrier plates 6. The unit assembled may be in any form of cross section desired, usually a parallelogram, and a rectangular or square cross section is most generally advantageous from a manufacturing and assembly standpoint. For a small device, one such unit with its plurality of spaced sheets 5 and edge-carrier plates 8 is suilicient. Larger devices are assembled by bringing together such number of units as desired in any case. In the illustration in Fig. 2, four such units are shown in assembly. The cross sectional shape of the housing 2 may be as desired in any given instance. A rectangular or square cross section is convenient generally. Where desired, a circular cross section may be applied, as indicated in dash lines 2' in Fig. 2, and in such case the corner edges 8 of the assembled units may be suitably anchgred to the inside of the circular shell. and the escape of fluids to the space laterally of the units may be prevented by securing headers l0 to close oil access at least below, or both above and below. 0r, for cylindrical columns of suitable size the units may be of cross-sectional shape to make up the segments of the circular cross section.

To feed liquid such that it may film down on the surfaces of the plates or sheets l, various feedform involves pieces or strips I2 of a wicking agent or a woven mesh, such as woven wire fabric, glass cloth, etc., these being superposed above the top edges of the plates 5, and extending through slits in the bottom of a liquid tray I3, and well up into the liquid which may be in such tray. The lower edge of each such woven mesh distributor element I2 is aligned with the top edge of a corresponding plate 5, and may be suitably secured thereto, for example conveniently by straddling alternate extending ends Il from the mesh work element. Thus each plate may be supplied with liquid traveling down on the mesh work and distributing to both surfaces' of the liquid and gas contact plate. Such feeder arrangement is in general satisfactoryl but in a further refinement we prefer to superpose a. second liquid tray I5 over the abovedescribed tray, and a plurality of feed elements or strips I6, which again may be of wicking or of woven structure, as for instance woven Wire textile, are arranged to extend through slits in the bottom of the tray I5 down into contact with the top edge of the feeder strips I2, and preferably at a transverse angle thereto. With such arrangement of superposed liquid trays and crossed sets of feeder elements, a 'particularly uniform and thorough distribution of liquid is attained. A connection I8 at the top of the housing allows entrance of liquid, and in fractionating column usage this may come from the condenser which is supplied by vapors from the connection 4. To prevent by-escape of vapors from the lower tray I3, the superposed trays I5 and I3 may have a. common wall 20, and this may be arranged to provide a cut-out or opening for a. vapor-pass from each unit at one side or centrally 2 I, as preferredin any case. The distributor elements I2 may be partly cut out as at 22, as desired, to facilitate vapor flow to the passway 2 I-.

In the operation of the apparatus, in general liquid is introduced above and gasiform fluid below. In fractional distillation, with the material to be fractionated entering at the inlet 3, the vapors rise through the passways between the sheets 5 and thence up through the spaces 22 and passway 2| to escape through connection 4 to the condenser. 'Reflux liquid back from the condenser, entering through connection I 8 flows into the upper tray I5 and down through the mesh work distributor elements I6 which in turn distribute the liquid to the distributor elements I2 which in turn distribute to the faces of the plates 5. Accumulating bottom liquid may be drawn oii as desired by valved outlet connection 24.

In some cases, particularly for simple equipment, a form of distributor element as illustrated in Fig. 4 may be applied. In this, an inlet feed tube I8', which may have an enlarged end section if desired, is provided with a woven mesh Work distributor element through a slit at the bottom. Preferably, the distributor element may be in two layers, one as illustrated at 25, Fig. 4, extending down in interrupted projections, and the other layer as a shorter portion 26 which in its lower edge extends only part way down on the projections of the layer 25. As many of these distributor connections may be applied as desired.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims, or the equivalent of such, be employed.

We therefore particularly point out and distinctly claim as our invention:

l. Apparatus of the character described, comprising a. housing, a plurality of vertical units therein each being an assembly of closely spaced parallel thin plates spaced by flanges at their lateral edges and open above and below, a feed inlet to the housing below said units, an outlet at the top of the housing, a reflux liquid distributor above and feeding said units and having a liquid tray and a plurality of woven wire feeder strips extending through slits in the tray bottom to the upper edges of the aforesaid thin plates and with projecting wires straddling the tops of the plates, and a, liquid tray .above the first-mentioned tray and having a plurality of woven wire strips extending through slits in the tray bottom to contact the top edges of the aforesaid feeder strips and at a transverse angle thereto, an inlet to the housing for liquid to the upper tray, and a vapor passway through the liquid trays allowing communication from the unit. f

2. Apparatus of the character described, comprising a. plurality of closely spaced parallel thin plates anchored at their lateral edges and open above and below, a liquid distributor above and feeding said plates and having a. liquid tray and plurality of woven mesh strips extending through slits in the tray bottom to the upper edges of the aforesaid thin plates and with projecting wires straddling the tops of the plates, and a liquid tray above the first-mentioned tray and having a plurality of woven mesh strips extending through slits in the tray vbottom to contact the top edges of the aforesaid feeder strips and at a. transverse angle thereto, and a. vapor passway providing communication between the spaces between said plates and said outlet.

3. In apparatus of the character described, a liquid distributing tray having a plurality of woven mesh strips extending through slits in the tray bottom, and a liquid tray above the firstmentioned tray and havingA a, plurality of woven mesh strips extending through slits in the tray bottom to contact the top edges of the afore-said strips and at a transverse angle thereto, vand a vapor passway providing communication with the spaces between said plates.

4. In apparatus of the character described, a liquid distributing tray having a plurality of liquid-distributing strips extending through slits in the tray bottom, and a liquid tray above the rst-mentioned tray and having a plurality of liquid-distributing strips extending through slits in the tray bottom to contact the top edges of the aforesaid strips and at a transverse angle thereto, and a vapor passway allowing communication from below.

5. Apparatus of the character described, comprising a housing, a plurality of vertical closely spaced parallel thin plates in said housing and spaced at their lateral edges and open above and below, a .vapor feed inlet to the housing below said plates, a vapor outlet at the top of the housing, a liquid distributor above said plates for feeding liquid to said plates'and having a liquid receiving means and a plurality of woven feeder strips passing through slits in the liquid receiving means, vthe upper portion of each feeder strip being located above its slit and adapted ,to contact the liquid in said liquid receiving-means, the entire width of each feeder strip extending downwardly from said upper portion, whereby the liquid flow along all portions of the width of each feeder strip is accomplished solely by the action of gravity, the lower portions of said feedliquid outlet at the bottom of said housing, and

a vapor passway through said liquid receiving means for conducting vapors to said vapor outlet from the spaces between said plates. said va. por passway having an elongated horizontal cross section extending transversely over all of said plates.

6. Apparatus of the character described, comprising a. housing, an assembly of closely spaced parallel vertical thin plates therein spaced at their lateral edges and open above and below, a vapor feed inlet to said housing for admitting vapor to the space below said plates, an outlet at the top of said housing for discharging vapors, a liquid distributor above said plates for feeding liquid to said plates and having a liquid tray with a plurality of woven feeder strips passing l through slits in said tray with the opposite edges of each slit contacting the opposite sides of the associated strip, the top portion of each strip be-` ing located above its slit and adapted to contact the liquid in said tray, the entire width of each feeder strip extending downwardly into contact with the tops of said thin plates, whereby the liquid ilow along all portions of the length of each feeder strip is accomplished solely by the action of gravity, an inlet to the housing for supplying liquid to said tray, an outlet for liquid at the bottom of said housing, and a vapor passway through said tray and extending transversely over said plates allowing communication from the spaces between said plates to said vapor outlet, said vapor passway being spaced from said slits so as to be free o! obstruction -by said woven feeder strips.

ROBERT E. BURK. vwTHOMAS J. WALSH.