Sept 9, 1947­ H. G. HCSRNBACHER Er AL. 2,427,142 STILL HEAD CONDENSER Filed ual-cn 2. 1943

Mrßsenr Q ¿6mm/musk' Jnhmtnta mvp ¿rows L' ¿Larp Patented Sept. 9, 1947 2,427,142

UNITED vSTATES PATENT OFFICE

STILL HEAD coNDENsEn Herbert G. Hornbacher, Essexville, and Lewis E. ­ Lloyd, Midland, Mich.,` assignors tovCorning ­Glass Works, Corning, N. Y., a corporation of l New York Application March 2, 1943, Serial No. 477,736 3 Claims. (Cl. 257-34) . l. ' 2 . The present invention relates todistilling ap Fig. 1 ls a plan view offa still head; paratus but more particularly to improved forms Fig. 2 is a sectional view taken along line =2­­­­2 of still heads. " ' ' s s of F18’. 1; `In the last two decades, laboratory distillation Fig. 3 is a sectional View taken on line 3--3 of technique and equipment has been substantially 5 Fig. 2; ~ improved. A considerable number of references Fig. 4 is a view similar to that of Fig. 2, but have appeared in the literature for laboratory of a modified form of the invention; . still heads alone. Several earlier publications on Fig. 5 is a View taken on line f5­­`5 of Fig. 4. ‘ still heads have suggested various types of de The still heads shown are based on a, principle, phlegmators. In the past ten years most of the 10 so far as applicants are aware, heretofore un suggested heads have been of the total condenser known. The basic principle of these new heads type. The majority of these heads have the prod consists in having a plurality‘of condensing sur uct take-off rate controlled by using a stopcock faces in parallel, one or more surfaces giving `as a variable orifice. The reflux ratio in these product while one or more others give reflux. heads is a function 0f both the rate of product 1lir These types of heads on laboratory stills have take-olf and the rate of distillation and is gen made possible much better distillation with con erally determined by counting the drops of re siderably less operator attention and many other flux and product. SuchV heads show several op advantages over previously suggested laboratory erating difûculties and undesirable characteristics still heads. ' i. such as uncertainty' and variability of the reflux 20 As heretofore stated, the basic principle of our ratio or` other major operating difûculties such as new still head is the use of a plurality of con vdroplets of water sealing the capillaries and super densing surfaces in parallel; the condensate from ycooling of the product?" Some of these heads are y one or more surfaces being taken as product While lalso so complicated and fragile as to render them that from the remaining surface or surfaces re y unsuitable for routine distillation work. Further 2,5 turns as reflux. Since the condensing surfaces ï’mcre, ­_the conventional still head is almost use are in parallel,­ the ratio of their condensates is lessf'for steam fractional distillations. One of the a function only of the geometry of the head and organic liquids being distilled is usually lighter is independent of the vertical fraction of` the than the other and the heavier settles to the bot condenser which is necessary to condense the `tom of the take-on? duct and comes out through 30 vapors at any given distillation rate. Of course, ' the partly closed stopcock while a disproportionate ` the ratio of the amounts condensed on different amount of the lighter liquid-which maybe the surfaces is proportional to the areas only if the desired product-_returns as reflux. , heat transfer is similar for the two >areas- and if The primary object of the present invention the vapors have similar paths to the several con is an improved form of still head. 35 densing surfaces. Another Objectis a constant reflux ratio still The multi-ratio glass still head designs illus

head. » ' ‘ ` ‘ trated in Figs. 1-5 have been found most suitable A further object is a constant reflux ratio still for laboratory application. ' head which may be readily adjusted to operate In the head shown in Figs. 1-3 the inner sur at any of a plurality of selected ratios. ' 40A face of the tubular condensing wall 30 is divided A still further object is an adjustable constant into segregated vertical strips, each of which . reflux ratio'still head'suitable for use on large serves as a separate condensing surface, by “guide capacity chemical apparatus. ` ‘ lines” ‘3| which may comprise glass rods fused lAnother object is a constant redux ratio "still to the condenser Wall. The bottom end of the ' head suitable for steam distillations. y ‘ ‘ 45 wall 3U is formed in saw-tooth fashion with the d Other objects of the invention will become ap‘ edges thickened by the glass rods and by beads parent' from a further perusal of the specification otherwise formed thereon so that the condensate taken in connection ¿with 'the accompanying collecting on the strips between guide lines 3l drawings.v w \ " l drains to collecting points of restricted width at In the' drawings 50 the bottom end of the wall 30. Thus, the con 2,427,142

. . 3 4 densate from a surface between any pair of guide at its upper end, has a seat into which the upper lines 3| may be kept from mixing with the re end of wall 50 fits. The use of reboiler 6| en flux, and can be delivered as product as will be ables one to accurately determine the equilibrium more fully brought out later. ' temperature between the boiling condensate The wall 30 is surrounded by a tubular Water and its vapor. The fitting 60 is of double-wall jacket 33 tapered and ground at the bottom to construction with lthe space between its walls fit into `the ground socket of a fitting 40 and evacuated to reduce heat loss therethrough. has a water intake tube 34 arranged tangent to The vent tube 56 passes through the double wall the condenser wall 30 so that the water Will take of fitting 60 and then projects upward outside a spiral course through the jacket on its way to 10 of tlâe wall 50 as most clearly brought out in an outlet tube 35. This swirling action of the ~ Fig. . cooling iiuid. gives uniform heat transfer con The reboiler 6| is supplied with fluid from a ditions all around wall 30 which is a prerequisite section of wall 50 by rod- 55 and reboiling accom for the correct operation of the head assembly. plished by introduction of an electric heating The head supporting fitting 40 may be built element in a tubular cavity 62 extending into for use of either a thermometer or a thermo the reboiler. A second thin walled tubular en couple for temperature indication. The well 4| try-way 63 enables introduction of a thermo is provided to accommodate a thermometer or couple into the reboiler. thermocouple and is protected from exposure to Attention, is directed to the fact that in the ' super-cooled reflux by a device 42 which defiects 20 structures of Figs. 2 and 4 the glass connections the super-cooled reflux draining over the well 4| between the fitting 40 and wall 33 and between to one side thereof. To gather product the fit fitting 60 and wall 50 are water cooled, thereby ting 40 has a product receiving line 43 having preventing thermal distribution. of lubricants an inlet opening 44 so located within the fitting usually employed in such connections. that the drip point between any pair of the con As will be readily understood, when using the verging guide lines 3| can be aligned thereover structures of Figs. 2 and 4 the product-redux in accordance with the ratio of product to reflux ratio is determined -by the fraction of the con desired. Liquid seal or trap 45 in the product densing area between the particular guide lines line 43 is provided to keep condensing condi at the time converging over opening 44. For ex tions constant. A vent tube 46 extends from 30 ample, the spacing of the relatively closely spaced the delivery end of line 43 through the wall of pairs of guide lines 3| is such that ratios 10:1, fitting 40 and thence projects well up into the 20:1 and 30:1 are available. Obviously, many interior of the tubular wall 30. As soon as the more guide lines may be provided if a greater trap 45 becomes sealed with liquid, vent tube number of ratio selections are desired. 46 furnishes an outlet `whereby uncondensed low Although in the examples of the invention illus boiling vapors may be exhausted from the still trated the variations of ratio are somewhat lim without fluctuations in pressure within the still lted, it will be readily understood that the inven being caused by the bubbling of such vapors tion contemplates division of the condensing sur through the trap, or without breaking the seal faces to obtain any desired ratios and that such in the trap and so allowing uncondensed vhigher variation in structure as well as others may be boiling vapors to pass out through the trap into made without departing from the spirit and scope the product line. of the invention. . We claim: steam distillation 1. In a still head assembly, a support, a con Steam distillation may be carried out in the denser mounted on said support and axially rotat same manner as dry distillation, the Water and able with respect thereto and having a condens organic liquid which condenses in a tube or be ing surface thereon, vertically extending ridges ‘ tween guide lines over a product receiving fun dividing said condensing, surface into a series nel being delivered as product while the water of parallel areas of different width, and collecting and organic liquid condensed on‘the remainder means mounted on said support in alignment of the condenser surfaces is returned as reflux. with an area of .said surface depending upon the rotary position of said still head with respect to Dístz'llatton of low boiling materials said support for the receipt of condensate there The modified form of head illustrated in Figs. from. , 4 and 5 has‘been designed for use in separating 2. In a still head assembly, a condenser unit or purifying -by distillation materials which start comprising a double-walled tubular body having to decompose below their boiling points. In this inlet and outlet conduits in communication with structure the guide lines 5| are arranged on the th‘e space between the inner and outer walls of outer surface of the tubular condenser wall 56. said unit, guide lines dividing the inner surface Cooling fluid enters the interior of Wall 50 60 of the inner wall into a plurality of condensing through a tube 52 and leaves through a tube surfaces parallel to the axis of'the unit, a sup 53 after having thoroughly washed the inner port for holding said unit in a vertical position surface of wall 50. A saw-tooth skirt 54 is fused and having a passage therethrough for placing to and forms a continuation of the bottom end the condensing surfaces in communication with of wall 50 and is arranged to function in the same 65 vapors to be condensed, and a product line pass . fashion as the corresponding part of Fig. 2 ing through a Wall of said support and having a structure. The product line 64, however, dif condensate receiving opening arranged to receive fers slightly from product line 43 of Fig. 2 in the condensate from one of said surfaces. that the trap or liquid seal 65 is arranged within 3. In a joint for use between a vaporizing ap the fitting. This prevents boiling of liquid in 70 paratus and a distilling head, a socket­ portion ` the trap and consequent breaking of the seal. for receipt of the distilling head and a hollow In addition to skirt 54, a rod 55 extends from apertured plug for 'establishing communication the wall 50 with its free end brought into the between the head and the vaporizing apparatus, a axial center of the assemblyand over a reboiler conduit arranged to capture part of the conden 6| arranged integral with a fitting 60, which, 75 sate from the head, a second conduit affording a 2,427,142 ' , 6 passage into the joint available for introduction of temperature measuring apparatus, and a de- l Nugàläeëzs A , Name Date fleeting device within the joint preventing con- 667’522 Pattison '______Jan. 5, 1897 densate from the distilling head from traversing 881’176 Hiller ______T- Feb. 5, 1901 Claude `______.__ Mar. 10, 1908 the passage afforded by said second conduit. 1 408’242 Armstrong ..-___-..-_ Feb. 28, 1922 HERBERT G. HORNBACHER. ’ 66’243 LEWIS E. LLOYD. ’ Morñt ______July 2, 1867 FOREIGN PATENTS REFERENCES CITED Number Country Date The following references are of record in them' 490,822 Germany ...... __ Feb. 4, 1930 file of this patent: ` . 22,826 Austria _'...... _.. Aug. 15, 1905 UNITED STATES PA 507360 Germany ______- Sept. 16, 1930 Number Name Date 1,673,373 Peters ______June 12, 1929 1s 626,780 Baker -_....-__--..___.. June 13, 1899