US2143904A - Reflux distributor for gas liquid contact apparatus - Google Patents

Description

REFLUX DISTRIBUTOR FOR GAs LIQUID CONTACT APPARATUS Jan. 17, 1939. c. s. wooDwELl.

Filed Feb. 27, 1937 Condenser F/ow ZZZ l .Box

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INVENTOR fara/0s Waas/we# Patented Jan. 17, 1939 UNITED STATES REFLUX DISTRIBUTOR FOR GAS LIQUID CONTACT APPARATUS Carolus S. Woodwell, Buffalo, N. Y., assigner to National Aniline & Chemical Company, Inc., New York, N. Y., a corporation o! New York Application February 27, 1937, Serial No. 128,143

8 Claims.

The present invention relates to gas liquid contact apparatus, and particularly to a device for feeding relux or scrubbing liquid to a fractionating or absorption column, respectively, of the packed 'tube type.

In distillation and absorption processes usingY a multiple tube packed column, it is advantageous to most eicient operation to return reflux condensate to the tubes of the still constantly and in uniform predetermined ratio to the various tubes throughout the period of distillation.

An object of the present invention, accordingly, is to provide means for effecting constant return of condensate in uniform predetermined ratio to the tubes of the still.

Further objects and advantages will be apparent from a consideration of the following description taken in connection with the accompanying drawing, wherein Fig. 1 is a vertical section through a fractionating column embodying the invention, parts related therewith being shown diagrammatically; and

Fig. 2 is a horizontal section taken on the line II-II of Fig. 1.

The fractionating column I is secured-at its lower end by a ange 2 to the upper end of a still 3, a portion of which is broken away in the drawing. A pipe 4 is communicably connected with the upper end of column I to conduct the vapor distillate to condenser 5. The condensate outlet from the condenser 5 is connected with a flow box 6 from which a portion of the condensate returns through the pipe 'I to the fractonating column and the remainder of the condensate is carried to the receiver 8 which is connected with the flow box 6 by a pipe 9.

In general, the fractionating column I is composed of a packed tube section I0 and a reflux distributing section I I, both of which are contained within a large diameter pipe I 2. Near the lower end of pipe I2 is a tube plate I4 secured about its periphery to the pipe. Within openings of the tube plate I4 are secured the lower ends of a multitude of spaced tubes I5, the diameter of which preferably does not exceed three inches. The tubes I5 are filled to a height at least 25 times the diameter of the tubes with conventional packing material IB which suitably may be Raschig rings. The amount of packing material in the tubes is so adjusted that each tube offers substantially the same resistance' to fluid ilow therethrough. The packing material in the tubes is supported by conventional means as, for example, a tapered spiral Il of Wire or a slotted cap ve equal portions. If it is desired to feed reux attached to the lower end of each tube. Spaced from the upper end of the pipe I2 is a second tube plate I8 which is also secured about its periphery to the pipe. The upper endsof the tubes I5 are secured in openings in the .plate 5 I8. The upper surface of the tube plate I8, as more clearly indicated in Fig. 2, is divided into a plurality of sectorial compartments within each of which is the upper end of one of the tubes I5. The division is eiected by means of uniformly 10 spaced upwardly extending radial bales 3| which are affixed at one end thereof to the inner cylindrical surface of the redux distributing section II and at the other end are joined at the center of the tube plate I8 (or are supported by means 15 of a cylindrical ring-not shown in the drawingat the center of the tube plate I8).

A sprayer I9 which is adapted to be rotated at high speed is provided to distribute reflux distillate returning through the pipe 'I which enters 20 the head I IA of the column above the tube plate I8. The upper end of pipe I2 is closed with a cover 20 which is secured to a flange 2| about the end of the pipe. Eccentrically placed in the cover is a sight glass 22 through which the distributing action within the pipe may b'e observed. Centrally placed in the cover is a bearing 23 within' the upper end of which is packing material held in place by packing nut 24. Shaft 25 carried by the bearing 23 is supported at its upper 39 x end by bearing 26 rigidly supported from the cover 20 by means of arms 21. To retain shaft 25 in proper vertical adjustment, safety collars 28 are provided thereon both above and below the bearing 26. Keyed to the upper end of shaft 25 is a drive pulley 29, driven from any suitable source of power. Secured to the lower end of the shaft is a horizontally rotating conical sprayhead 3|) forming a cup into which the return pipe 1- deiivers the returned distillate. The 40 sprayhead may be in the form of a ilat plate or solid cone instead of the cup or inverted cone shown in the drawing. In operation the particles of liquid discharged from the rapidly rotating sprayhead 30 will impinge against the inner cylindrical surface of the column head |I at points above the edges of baille members 3|. As sprayhead 30 delivers an equal quantity of distillate in all directions the quantity delivered to each compartment and hence to each tube is equal.

In the embodiment of the invention shown, the top of tube plate I8 is divided into five equal compartments for dividing the reux uniformly into or scrubbing liquid uniformly in predetermined unequal portions to the packedtubes, the radial baies are so disposed that the angles therebetween are proportional to the desired divisions of liquid.

The chamber in the tube section I between the tubes I may contain air which dissipates the heat, or, if desired, it may be equipped with a suitable inlet 32 and outlet 33 for circulating any fluid in heat exchange relation with the tubes I5, if such is desirable for the particular material being fractionated, or it may be filled with a suitable packing material, for example, infusorial earth, glass, Wool asbestos, to decrease radiation.

In operation, material is introduced into still 3 in any suitable manner and is heated to drive vapors upwardly into the fractionating column I. The system may be run under reduced pressure applied to the receiver if desired. Vapors rising in the column I enter the tubes I5 where they are fractionated by their passage countercurrent to the reflux. The vapors after partial condensation due to fractionation enter the co1- umn head I I which they leave by way of the pipe 4, by which they are conducted to the condenser 5. The condensate therefrom is delivered to the ow box 6 from which a portion is returned to the head I I and the remainder is delivered to the receiver 8. 'I'he portion of the condensate admitted to column head II by means of pipe I is allowed to ilow continuously upon the upper surface of the revolving cup 30, the centrifugal force exerted by the rotating cup causing discharge of the liquid in the form of a. substantially continuous liquid sheet or curtain of spray. The discharged condensate strikes the innerv cylindrical surface of the column head II and is evenly distributed thereover. It then flows downwardly, and the edges of the baffle members 3| effect a subdivision of the liquid into a plurality of equal portions each of which collects in an appropriate sectional compartment formed by adjacent baille members. The liquid portion thus collected in each compartment flows into the tube opening located therein. As the tubes are of equal diameter and are so packed that they offer substantially equal resistance to fluid flow, and the reux to each tube is equal, the fractionation obtained in the various tubes is equal, thereby maintaining the efficiency of the unit. Thus, a unit containing a multiplicity of tubes three inches or less in diameter, packed to a height of eight feet with or 1A inch Raschig rings, has an eiliciency equal that of a thirty to thirty-five plate column of the bubble cap type. A

In the preferredembodiment of the invention disclosed, the various tubes are of equal diameter and the baffles 3| are equally spaced. However, the invention is not limited thereto but includes the use of tubes of different sizes in conjunction with radialballes spaced according to the cross sectional area ofthe tubes. In either case the liquid is uniformly distributed to the tubes in the ratio set by the spacing of the radial bailies.l

Moreover, if desired, the bailes may be spaced to distribute the liquid uniformly in either equal or unequal predetermined portions regardless of the sizes of the tubes to which the portions of liquid are delivered.

While the apparatus of the present invention in a preferred aspect is adapted to use in a proc- .fess of fractionation, in its broader aspect it is adapted to use in processes generally wherein eilicient contact-of liquid and gas is desired. For

example, in gas absorbing and scrubbing towers the gas inlet would be at the bottom of pipe I, and the wash fluid would be delivered to the upper ends of tubes I5 by the pipe I and sprayer I9.

It should be understood that the term gas as used in the appended claims refers to the physical state, regardless of whether or not the gas is condensable to a liquid at the operating temperature by pressure alone.

As various changes may be made in the specific embodiment without departing from the invention, it will be understood that the invention is not limited thereto.

I claim:

l. A fractionating column of the packed tube type, comprising a multiplicity of vertical tubes, a header plate into which said tubes extend, means on said header plate forming a plurality of compartments with each of which the upper end of one of said tubes communicates said column having an outlet located above said compartments for removal of fractionated vapors from said column, and means for introducing and distributing liquid among said compartments.

2. A gas-liquid contact column comprising a multiplicity of tubes of equal cross-sectional area, means for introducing a gas into the lower ends of said tubes, means joining the upper ends of the tubes into a head, a plurality of compartments in said head with each 'of which one of said tubes communicates, said column having an outlet located above said compartments for removal of said gas from said column, means for introducing a stream of liquid into said head and means in said head to distribute the said stream of liquid uniformly among said compartments.

3. A fractionating column of the packed tube type, comprising a multiplicity of vertical tubes of equal cross-sectional area, means joining the upper ends of said tubes into a head, bailles dividing the upper surface of said means into a plurality of compartments in each of which one of said tubes terminates, said column having an outlet located above said bailles for removal of fractionated vapors, means for introducing reflux into said head and a sprayer for distributing said reflux uniformly among said compartments.

4. A fractionating column of the packed tube type, comprising a multiplicity of vertical tubes, means joining the upper ends of said tubes into a head, radial baiiles dividing the upper surface of said means into a plurality of radial compartments in each of which one of said tubes terminates, said column having an outlet located above said bailles for removal of fractionated vapors, means for introducing reflux into said head and a horizontally rotating spraying disc upon which the introduced reilux is delivered for distributing said reilux uniformly among said compartments.

5. A fractionating column of the packed tube type, comprising a multiplicity of vertical tubes, a tube sheet joining the upper ends of said tubes into a. head, radial bailles dividing the upper surface of said tube sheet into a plurality of radial compartments in each of which one of said tubes terminates, said column having an outlet located above said bailies for removal of fractionated vapors, means for introducing reflux into said head and a horizontally rotating sprayer for distributing said reflux uniformly among said compartments.

6. A fractionating column comprising a multiplicity of packed spaced tubes joined at their respective ends by tube plates, means for delivering vaporous distillate to the lower ends of said tubes, an opening in said column above the upper end of said tube plates through whichvaporous distillate may leave said column, and means for Idistributing a portion of said distillate which leaves said column after having been condensed uniformly in equal portions among said tubes,`

said means comprising upstanding radial baffles dividing said upper tube plate into a plurality of equal radial compartments in each of which one of said tubes terminates, and a horizontally rotatable sprayer onto which said portion of distillate is delivered whereby it is distributed equally among said compartments and henc among said tubes.

'7. In a fractionating system of the type having a fractionating column and means for condensing distillate removed from the column and returning a portion of the condensed distillate to the column, a fractionating column of the packed tube type, comprising a multiplicity of tubes spaced from each otherl and having packing material therein, means for introducing vapors into the lower ends of said tubes, means joining the upper ends of the tubes into a head, means to Withdraw fractionated vapors from said head, baies on said means joining the upper ends forming a plurality of compartments within each of which one of said ,tubes terminates, and means in said head to distribute the returned portion of condensate uniformly among said compartments.

8. A fractionating column comprising in combination a vertical hollow shell, vertically spaced tube plates .located within said shell, a plurality of spaced vertical packed tubes extending between and secured to said tube plates, all of said tubes being of uniform cross sectional area, said tube plates and shell defining a header located above said upper tube plate and a header located below the lower tube plate, said rst named header having an outlet for removal of gas from said column, means within said rst named header forming a plurality of compartments with each of which the upper end of one of said packed tubes communicates, means for introducing liquid into said upper header, a horizontally rotating sprayer for continuously distributing liquid among said compartments, said compartments being of substantially uniform size whereby said liquid is substantially uniformly distributed simultaneously into all of said packed tubes, and means for introducing vapors to be fractionated into said lower header.

CAROLUS S. WOODWELL.

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