US2508394A - Fractionating column - Google Patents

Description

May 23, 1950 Filed llay 10. 1946 H. J. JOHN- 2,508,394

FRACTIONATIQG comm 2 She'ets-Sheet 1 HARRY J. JOHN J 3mm May 23,1950 H. J. JOHN FRACTIONATING COLUMN Filed Ilay 10. 1946 HARRY 4.06m

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Patented May 23, 1950 UNITED STATES PATENT OFFICE (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 1 Claim.

This application is made under the act of March 3, 1883, as amended by the act of April 30, 1928, and the invention herein described and claimed, if patented, may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment to me of any royalty thereon,

This invention relates to rectifying or fractionating devices including columns or towers and is more particularly concerned with the packing used therein to effect contact between rising vapors and downwardly flowing liquid.

In general, the objects of this invention are to provide packing of the type mentioned which is simple, which effects highly eflicient fractionation, high throughput and small H. E. T. P. (height equivalent to a theoretical plate).

These objectives are accomplished in accordance with this invention by providing packing of mesh or screen material in forms which distribute the refiux in thin films over wide areas in the path of the rising vapors in the column and which provide a longer path of travel for the ascending vapors without necessitating an in- .crease in the overall height of the column or tower.

This invention, including some of its possible modifications. is illustrated in the accompanying drawing and described hereinafter, from which a full understanding of the invention may be had and from which other objects and advantages will be apparent.

In the drawing:

Figure 1 is an elevational section of a portion of a fractionating column containing one form of packing in accordance with this invention.

Figure 2 is an exploded view of the packing elements of Figure 1.

Figures 3, 5, 7, and 9 are views similar to Figure 1 showing modified forms of packing elements.

Figures 4, 6, 8, and 10 are exploded views of the packing elements of Figures 3, 5, 7, and 9, respectively.

Referring with more particularity to the drawing in which like numerals designate like parts, the embodiment illustrated in Figuresl and 2 shows a tubular column ii, wherein packing elements in the form of foraminous discs l2 and I3 are disposed vertically spaced therein. These discs are each fabricated from flat screen material, preferably of a non-corrosive type. An important feature of each disc is that in its normal state it is ameter of the column II. when the disc is disposed in the tubular column, it is forced'to assume a bowed position to impart thereto a uniform arcuate contour. By these means, the resiliency of the meshed material creates a continuous pressure between the edge of the disc and the wall of the column, thereby holding the disc in place. The edge of the disc under the resilient action of the material also adjusts itself to any irregularities of the column wall and thereby prevents leakage between the disc and wall.

The adjacent discs l2 and I3 have cut-out sections l4 and I5, respectively, extending from the edges of the discs toward the centers, and the discs are disposed in the column so orientated as to locate the cut-out sections approximately on opposite sides of the column. Vertical screens in the form of tabs as shown at 16 and I! are interposed between adjacent discs, over which the liquid flows from one disc to the other, substantially as illustrated. The rising vapors pass upward through the sections l4 and I5, which cause the vapors to travel back and forth across the column as they rise and to contact the liquid flatandthe diameter is larger than the inside difilm on the discs and tabs.

Although the mesh of the wire screening from which the discs are made can be varied depending upon the liquid to be fractionated, it will ordinarily be desirable to confine it to the range of 30 to for most reflux liquids.

The embodiment illustrated in Figures 3 and 4 is similar to that shown in Figures 1 and 2, except that the tabs l6 and I I are not used. Instead, pairs of discs i8 and I9 having diametrically opposite cut-out sections 20 and 2i are bowed in opposite directions and placed in juxtaposition with their concave sides facing each other. This effects a direct physical contact between the two discs for liquid flow and provides a lateral space between the discs for the passage of vapor. Better distribution of liquid dropping from one pair of plates to the next may be effected by the use of distributors 22, as shown in Figures 5 and 6, such as wires or other suitable devices, secured between pairs of adjacent convex surfaces. These distributors may be secured to the discs by welding or otherwise.

Where it is desired further to increase the illm area, additional vertical screen material may be interposed between the adjacent discs. In the embodiment illustrated in Figures 7 and 8, discs 24 and 25 without tabs are disposed in the column. The concave and convex surfaces of adjacent discs face each other, and the discs are spaced apart with additional screen devices 26 interposed beselves are split at one point, as shown at 23A,

and are slightly larger than the inside diameter of the column so that they can be wedged into the column in a tight fit.

The embodiment illustrated in Figures 9 and 10 employs diil'ergent forms of discs 21 and 28, the disc 21 having a cut-out section 28 on .one side and the disc 28 having a central aperture ll. These discs are spaced apart in alternating relation and between them is disposed a coil of screen material 3| in the form of a clock spring.

The discs 21 and 28 abut either sideof the coil by means of which vapor enters and is led either into the center of the coil or the outer edge thereof and travels in the opposite direction between the convolutions of the coil before passing upward through the next disc. The vapors pass through one coil in the directiomopposite to its immediately preceding coil. By the use of these coils, the path of the vapor is. increased manyfold as the vapor rises through the column, and

' at the same time additional film areas of the reflux liquid are exposed on the screen coil.

In this embodiment of the invention, it is preferable to employ fiat discs so that contact therewith is made along the entire edge 01' the screen coil 'or else the thickness of the coil may be varied to provide for such contact.

It is to be understood, however, that materials tubular column,

4 other than screens or wire gauze may be used, including porous materials. Where any materials are used for the packing to fabricate the discs which are not resilient or flexible enough to wedge them into the column, they may be secured in position by means of the rings 23, illusrated in Figures 7 and 8.

Having thus described my invention, I claim: A fractionating device comprising a vertical foraminous discs vertically spaced therein, each disc being fabricated from screen material, being flat in its. normal state. having a diameter larger than the inside diameter of the column, and having a cut-out section extending from the edge thereof toward the center, each disc being disposed in the column in forced bowed position to impart thereto a uniform arcuate contour and with adjacent discs so orientated as to locate the cut-out sections approximately on opposite sides of the column,

the resiliency of the discs creating a continuous pressure between their edges and the wall of the column, and vertical screens interposed between adjacent discs.

HARRY J. JOHN.

REFERENCES CITED The following references are ofrecord in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,227,164 Stedman Dec. 31, 1940 2,325,8f8 Weithamp et al. Aug. 3, 1943 2,336,060 Bragg Dec. "1, 1943 2,375,336 Weithamp May 3, 1945

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