Патент USA US2109129код для вставки
Patented Feb. 22, 1938 2,109,129 I UNITED‘ STATES PATENT OFFICE 2,109,129 APPARATUS FOR HIGH VACUUM DISTILLA ' TIONS Eric William Fawcett and John Iiewis McCowen, - Northwich, England, assignors to Imperial Chemical Industries Limited, a corporation of Great Britain Application July 30, 1936, Serial No. 93,338 Inv Great Britain March 7, 1934 8 Claims. _(Cl. 202-205) I This invention relates to improvements in ap paratus for high vacuum distillation; and it com prises an apparatus organization for high vacu horizontal surfaces; um distillation of materials yielding upon dis the apparatus of Fig. 1; section and partly in elevation, of a still having Fig. 2 is a view illustrating a modi?cation of ' Fig. 3 is a diagrammatic view, partly in vertical 5 5 tillation at least one non-?uent component, com prising a chamber adapted to be evacuated, - section and partly in elevation, of ‘a still having ' means providing a hot surface in the chamber, vertical cylindrical surfaces; and _Fig. 4 is a detail view to show the shape of means providing a cool surface in, the chamber ‘and means in the chamber for scraping at least the scrapers in the apparatus of Fig. 3. In the drawing, in which like reference char- 10 '10 one of said surfaces to remove materials there from; all as more fully hereinafter set forth and acters indicate like parts, Fig. 1 shows a hori zontal type Still. It comprises a cylindrical dis v . The invention relates to the distillation under , tillation chamber Hi, the upper inner surface of high vacuum of substances, liquid or solid, which which, indicated at H, forms the cold or con15 yield either a solid (1. e. non-?owing) distillate, densing surface. The chamber has a head l2 on or a solid residue,_or both, and more especially one end. The upper portion of the cylinder is to molecular distillation in which the distilling provided with a jacket I3 de?ning .a chamber [4 and having an inlet l5 and outlet I6 for circula and condensing surfaces are in very close prox imity, namely of the order of the mean free path . tion of cooling liquid. The cylinder is mounted 20 of the distilling molecules at the pressure within for rotation in a stationary head box ii, a suit as claimed. 4 _ 15 able ?anged, vacuum-tight rotary joint being 20 the apparatus’. The principal object of the‘ invention is to . provided as indicated at Ill. The head box has provide a means for overcoming the di?iculty of an outlet I9 adapted to be put in communica removing the solid distillation products from the tion with a high vacuum pump (not shown), and 25 distilling or condensing surfaces, a difficulty an outlet 20, closed by a vacuum-tight valve in- 25 dicated at 2|, for withdrawal of condensate. which has hitherto hindered the commercial ap plication of the technique of high-vacuum dis~ 30 The hot surface takes the form of a shallow tillation to the treatment of solid substances or tray 22 suitably supported adjacent the upper, substances yielding solid products. part of cylinder l 0 as by a bracket 23 and spaced The present invention is 7applicable to the treatment of initial substances whichare solid under the distillation conditions and which yield a solid residue or distillate under these condi tions, i. e., a process which from one aspect may 35 be regarded as "high vacuum sublimation", also to the treatment of substances which initially are liquid or which are introduced to the heating surface or surfaces incorporated with a liquid carrier medium to form a fluent mixture, and 40 yield a solid residue or distillate. . The invention comprises the provision within a vacuum distillation chamber of an intermit from the cold surface li a centimeter or there- 30 abouts. The tray is adapted to contain a thin layer of material to be distilled, indicated at 24. The tray is heated by an electrical heating ele ment indicated diagrammatically at 25 and sup plied with current by wires 30. ' , Material to be distilled is introduced into the tray through a manhole 3| hermetically closable by a cover 32. In ?lling the tray, the manhole is brought to the top by turning cylinder H). In operation, material, e. g. beta-aminoanthra~ 40 quinone or other substance referred to post, is distilled and condenses as a non-?uent crust or tently or continuously operated scraping device the like on surface ll. Means are provided for adapted to traverse the condensing surface (or removing the adhering condensate, comprising a 45 surfaces) on the distilling surface (or surfaces) scraper ring 33 advantageously of the type of an 45 or both, removing by scrapingso'lid material from engine piston ring and making a snug sliding ?t in cylinder Ill. The ring has attached thereto a the said surfaces, and depositing said solid mate spider 34 having a central nut 35. The ring is rial in a suitably disposed receptacle or recep adapted to be moved axially along the length of - tacles from which the solid material can be re 50 moved as desired. In the accompanying drawing is shown, more or less diagrammatically, three examples of spe ci?c embodiments of apparatus within the pur view of the invention. In the drawing, 55 Fig. 1 is a diagrammatic view, partly in vertical the cylinder by means of a threaded shaft 36, 50 engaging the ‘nut and journaled in head l2 as at 31. A reversible motor 38 mounted inside head box I1 is arranged to drive the shaft as shown. Upon operating the motor, the ring is caused to move the length of the chamber I 0 and scrape 58 2 2,109,129 material towards the outlet 2|. In order to pre tioned adjacent the lower portion of the cylinder, vent material scraped off by'the ring from fall as shown, and delivers through an outlet conduit ' ing back into the tray, cylinder It is rotated 60 to an outlet Si in chamber 50, valved as at 62. v This means is for removing undistilled residue. Scraper means are provided, comprising a sharp-edged scraper blade ‘I engaging the sur face of cylinder SI and mounted at top and bot tom on rings as adapted to be supported for re tation in an annular groove 8'! at each end» of manually or otherwise, through a su?lcient angle to prevent such falling back, prior to actuating the scraper. ' . As an example of the use of this still, a typical evaporative distillation operation may take from one to two hours. Distillation is started as de 10 scribed and when a‘ thin layer of condensate forms on surface, II to a predetermined thickness cylinder 5|, as shown. The scraper advantage ously has a cross-section such'as shown in Fig. 4. which may occur every ten or ?fteengminutes, drum II is tilted and the scraper ring set in operation, and is moved the length of the cylin der from left to right and then back again. The drum is then tilted back and distillation is ref Rings 66 are provided with rims 68 having gear teeth. The rings are driven by‘means of two sumed. The time required for the traverse of the scraper may be half a minute or less, so that the scraping time is usually negligible compared with the operating or distilling time. Fig. 2 shows a modi?cation'yin which periodic tilting of the cylinder is done'away with. In this modi?cation, a_ modified ring II is providedcut away at the top, as shown, carried-by a spider ll driven by shaft 36. The spider has a guide pinions 89 mounted on a shaft ‘Ill Journaled as at 1| in brackets 53 and extending out through 15 cylinder ill. The exposed end of the shaft is pro vided with a handle ‘II. A vacuum-tight bearing ‘I3 is \provided to prevent leakage'around the _ shaft. Upon rotating the handle, the scraper is caused tomove over the cold surface and remove material adhering thereto, which falls to. the bottom of chamber 50. If desired, shaft 10 may be operated by an electric motor as in Fig. 1. The apparatus is shown as also having a scraper adapted to remove any material from the‘wall portion 42 cooperating with a rail 43 on the lower . of cylinder 54. This is advantageous where ‘the portion of the tray structure, so as to keep the distillation residue is non-?uent in character. spider from rotating while allowing lengthwise Thus, a scraper bar ‘It is provided engaging cyl motion. In this modi?cation, cylinder II is ar inder 54 and supported from rings it by support ranged-with an outer jacket it completely sur ing members 15 and ‘It as shown. ' t rounding it, so‘that the entire surface is cooled. In operatiomcylinderll is rotated slowly and In operation, the ‘apparatus is put under very high vacuum through. outlet l8. Cylinder 54 is brought to proper temperature and cooling ?uid is circulatedv through chamber I2. Through pipe continuously, as by a belt 45 and pulley 4i driven by suitable slow-speed power means, not shown. Thus condensate is continuously brought to non ‘ 51 is fed the substanceto bedistilled. Fluid mix- _ fouling position and is removed during opera ,ture flows over hot surface I4 ‘and is subject to tion. In thismodi?cation, it is advantageous to ' evaporation in its downward course. vaporizing operate the ring, in the outward (right-to-left) ~ constituents condense on cold sm'face II. From ' direction, at a fairly rapid rate, so that the ring time to time or continuously, handle ‘I! is turned will not force any appreciable amount of con to cause material to drop from the cold surface densate outward. In practice, suitable swivel into the lower portion of chamber SI. Undis conduit connections (not shown) are. provided tillable residue, if any, drops into collector W. for the ?ow of cooling water to permit such cir ' From time to time, undistillable residue is taken culation while the cylinder rotates. ' of! through valve 82 and the distilled product is _ The stills of Figs. 1 and 2 are wellsuited not, only for distilling liquid materials which give. taken oifthroughvalvellk ' These stills- are usually made of steel or stain less steel, and can be made in any other material non-?uent distillates, but also for distilling ma terials in which the raw material, the residue and the distillate are all non-?uent.‘ Powdered solid materials can readily be spread on the tray and any residue scraped or- otherwise removed from the tray after distillation is ?nished. - In a typical process makinguse of the pres 50 having a vacuum outlet is communicating with a high vacuum pump (not shown), and an tion. The '?uent mixture was fed through pipe to suit particular requirements. " ent invention, a quantity of crude beta-aminoan thraquinone to be puri?ed (melting point about 298° C.) was mixed withabout an equal weight of ' Fig, 3Vshows a modification particularly well a petroleum oil which had previously been freed adapted for continuous operation. The apparar by evaporative distillation, of all matter volatile tus comprises a cylindrical distillationwchamber under the conditions of the evaporative distilla 55 outlet 2. with valve 2|, as in Fig. 1. In this ' still, the cold surface takes the form of a double‘ walled cylinder 5| enclosing a chamber Hand an outlet connection I! and outlet It for cold water 5'! of the apparatus of Fig. 3 to the hot surface, ‘ which was maintained at about 120° C.‘ A vac uum was maintained in the'chamber of the order ' of 10-5~ mm. of mercury.'_ The cold surface in this example was 2 cm. from thevhot surface. or other cooling ?uid circulated through the chamber. Thejcylinder is supported from the distillation chamber walls by brackets 53. The Pure beta-aminoanthraquinone ‘(melting point hot surface takes the form of a hollow cylinder the hot surface and were removed through out 65» let ", together with the petroleum oil. The con- _' 54 concentric with and closely adjacent cylinder 51 and having inside it any suitable heating 311° C.) evaporated off and condensed on the cold surface, while the impin'ities remained on means, indicated by way of example as an elec densate was removed by slowly rotating the trical resistance heating coil 55 supplied by wires scrapers. » In carrying out such process in the apparatus 70 70 30. The bottom of cylinder M is closed by a ta pering cap 56 as shown. Material to be distilled of Figs. 1 and 2, the crude solid material can be is fed in ?uent condition through an inlet pipe put directly in the tray. Condensate is removed 51 and is distributed in a thinv ?lm to the outer. by operating the scraping .ring as described. , surface of cylinder I4 with the aid of a conical As examples of distillation operations to which ,16 distributor It. A funnel-like collector I! is posi the present invention may be applied with ad 76 3 mouse vantage, may be mentioned the extraction of caf feineifrom ground dried coffee beans, the extrac tion of quinine from barks containing the same, the puri?cation of crude beta-aminoanth'raqui none, etc., in all which cases a solid distillate is obtained which is removed according to the in vention. In distilling these (solid) materials in - the apparatus of Fig. 3, they are dissolved or suspended in comminuted form in a carrier me the chamber for scraping at least one of said sur faces to remove materials therefrom. ' .4. Apparatus for high vacuum distillation of materials yielding upon distillation a non-?uent‘ distillate, comprisingv a chamber adapted to be evacuated. means providing a hot evaporating surfacewithin the chamber, means providing a cool condensing surface in the chamber closely ‘ spaced'from the hot surface and adapted to re ceive the distillate, and means in the chamber for 10 10 dium of such character as toform a ?uent mix vscrapirig?the cool surface to remove condensed ture under the conditions of distillation; e. g., a linseed stand oil or a petroleum oil which has‘ material" therefrom, so as to expose the cool sur face-for’ reception of distillate. been previously freed of light volatiles by evapo 5. Apparatus for high vacuum distillation of rative distillation. In the apparatus of Fig. I, materials yielding upon distillation a non-?uent 15 15 the materials can be put directly in the tray in distillate, comprising a chamber adapted to be comminuted form. . This case is a continuation-in-part of our prior evacuated, a ?at horizontal member arranged to a hot surface and to retain a body of raw application, Serial No. 9,873, ?led March '7, 1935. provide material to‘ be distilled, closely adjacent means What we claim is: 1. In a ‘molecular distillation apparatus having providing a‘ cool surface for condensing distilled 20 20 material within the chamber, and means in the an element providing a hot surface, the combi chamber ‘for scraping the cool surface to remove nation of scraping means, means providing. a con condensed material therefrom. densing surface closely spaced from the hot sur 6. In a high vacuum distillation apparatus face at a distance of the same order as the mean adapted for distillation of materials yielding a 25 - free path of molecules to be distilled, and means non-‘fluent distillate upon distillation and having so constructed and arranged as to eil'ect relative movement between said scraping means and said means providing a heated surface and a closely cold surface vfor condensation of such ma condensing surface so as to remove distillate spaced terials, the improvement comprising a member from the condensing surface. arranged in contact with the cold surface and 30 2. An apparatus for effecting short path high movable‘ with respect thereto, and means for vacuum distillation comprising means providing moving said member over the cold surface to de-' a cooled condensing surface, an evaporating sur tach condensate therefrom. face substantially parallel to the said condensing '1. Apparatus for distillation of materials hav surface and located a distance therefrom of the ing non-fluent components, comprising means same order as the mean free path of molecules providing a heated surface, means providing a to be distilled, means for distributing material to cooling surface closely spaced therefrom, means for scraping at least one of said surfaces to de be distilled over the evaporating surface, a scrap ing device in sliding contact with the cooled con tach non-?uent materials therefrom and a hous densing surface and adapted ‘to scrape the cooled ing enclosing said surfaces and said scraping means. condensing surface, said evaporating and con 8. In a molecular distillation apparatus having densing surfaces being enclosed so that they can be maintained under high vacuum, and a recep— an element providing a hot surface, the combi tacle for the reception of material scraped from nation of scraping means, means providing, a condensing surface closely spaced from the hot condensing surface. ‘ ' ‘ 45 the3. said Apparatus for high vacuum distillation of surface at a distance of the same order as the materials yielding upon distillation at least one mean free path of molecules to be distilled, and non-?uent component, comprising a chamber means so constructed and arranged as to effect adapted to be evacuated, means providing a hot relative movement between said scraping means and said hot surface so as to remove residue from evaporating surface in the chamber, means pro . .viding a cool condensing surface in the chamber the hot surface. closely spaced from the hot surface and adapted to receive the distilled component, and means in ' , ERIC WILLIAM FAWCE'I'I‘. JOHN L MOCOWEN.