US2505571A

US2505571A - System for distilling decomposable liquids

Info

Publication number: US2505571A
Application number: US10676A
Authority: US
Inventors: Ormont Bernard
Original assignee: ARTHUR W DRAKE
Current assignee: ARTHUR W DRAKE
Priority date: 1946-02-20
Filing date: 1948-02-25
Publication date: 1950-04-25
Anticipated expiration: 1967-04-25

Description

B. oRMoNT 2,505,571

sysma Fox DISTILLING- nEcomPosABm mquxns Filed Feb. 25. 1948 atented im 25 1950 SYSTEM FOR DISTILLING DECOMPOSABLE LIQUIDS Bernard Ormont. New York, N. Y., assigner to Arthur W. Drake, Short Hills, N. J.

Application February 25, 1948. Serial No. 10,676 In France February 20, 1946 Section l, Public Law 690, August 8, 1946 Patent expires February 20, i966 5 Claims. l

This invention relates to a process of and apparatus for the Vaporization and distillation of liquids in a single phase at temperatures Well below their atmospheric boiling points and without the` use of special mechanical equipment for the production of vacuum. The present art and practice used for vaporization of liquids, With atmospheric boiling points above the cracking or decomposing temperature of said liquids, entails the use of steam and heat in vacuum, the vacuum being established by the use of mechanical equipment designed for that purpose, but this method is not only costly to install but is hazardous in operation and requires highly skilled workers in order to operate the system.

This invention, described below and set forth in detail, provides for a process for the use of high vacuum distillation in the presence of gases and heat, which process is more eicient, less costly, more flexible, and much safer, than any operation heretofore proposed, and embodies all the advantages of high vacuum distillation and also molecular vaporization without the necessity oi employing expensive equipment with the accompanying costs, hazards and disadvantages. With this in View, the present invention resides in the novel details of construction and combinations oi parts constituting the apparatus, as well as in the novel steps and combinations of steps constituting the process, all as will more iully appear hereinafter and be particularly covered by the claims.

Referring to the accompanying drawings forming a part of this specification and in which like numerals designate like parts in all the views, s

Fig. 1 is a diagrammatic illustration partly in section and partly in elevation illustrating one form of apparatus for vaporizing the liquid; and

Fig. 2 is a diagram of a system in which the vaporizer of Fig. 1 is incorporated.

This process and invention is based on welllmown and well-recognized physical laws, among which is that which statesthat the molecular weight in pounds of any substance, when vaporized, Will occupy a Space of 359 cu. ft. For instance, if we take a liquid or substance of a molecular Weight of 20 (such as liquid A for example in the following description), then 20 lbs. of this particular liquid or substance when vaporized will occupy 359 cu. it., or 1 lb. will occupy very close to 18 cu. ft. 1f we take another substance of av molecular weight of 180 (such as liquid B for example in the following description), the molecular weight in pounds would then be 180, and when vaporized would occupy a simi;

lar space of 359 cu. ft.. or 1 lb. would occupy very close to 2 cu. ft. So it will be seen that the ratio of the expansion of these two substances when vaporized is 10 to 1. i

With reference to Fig. 1, wherein there is illustrated one form of apparatus for carrying out this invention, the liquid of low molecular weight is identified by the letter A and the liquid of high molecular weight is identified by the letter B. There is provided a pipe C into one end of which extend two smaller pipes D and E through a suitable closure member. The open end of pipe E is relatively close to the closure member, but pipe D extends well beyond the end oi pipe E and approximately to the farther end of pipe C,

`the end of pipe D also being open. Heat is applied externally to pipe C and the vapors gen- `e-rated therein escape at F. The liquid (A.) ci

low molecular weight will pass from the open end of pipe E on to the inner surface of pipe C and be heated thereby. The small open circles represent the molecules of liquid A as they flow in the direction of the arrow along the bottom oi pipe C, said molecules becoming hotter and hotter until linally they vaporize as at point or area G. We will assume that the temperature at Gr is 300 F. and that liquid A has a molecular Weight of 20 and is completely vaporized at this point, the vapors passing through the remainder ci pipe C and escaping at F.

Let us consider what is happening at point G. In l gallon there are 231 cu. in. and, assuming atmospheric pressure to be present in pipe C, the pressure will be 760 millimeters. We will assume that one gallon of liquid A weighs 8 lbs. lt was pointed out above that one pound of liquid A upon vaporization occupies 18 cu. ft. If we di-u vide 231 cu. in. by 8 We find that l 1b, of liquid A occupies close to 29 cu. in., but the same pound of liquid A when vaporized occupies 18 cu. it. or 31,104 cu. in. Hence there is an expansion in volume of liquid A, in going from the liquid to the vapor state, of close to 1,000 times its original volume. Considering one molecule of liquid A, at 760 millimeters pressure, being converted into a vapor at 300 F., it will be seen that the volume originally occupied by the liquid molecule is increased l,000 times, or stated in other words the pressure in the original molecular volume is reduced to .76 millimeter. This is graphically indicated in Fig. 1 by the dot-and-dash circle within pipe C at area G.

We will now consider liquid B of which, as pointed out above, one pound when vaporized occupies 2 cu. it. and whose characteristics are that it has a boiling point of 900 F., a cracking point of 600 F., and that it vaporizes completely at 300 F. in a vacuum of l1 millimeters. Liquid B is conveyed through pipe D inside of pipe C, thereby being'preheated during said conveyance, and then said liquid passes through the open end of pipe D and on to the inner surface of pipe C, ilowing along said surface in the direction of the arrow toward point or area G. Molecules of liquid B are represented by the series of filled-in or solid circles. Upon reaching area G this liquid will have been heated to 300 F.

As the molecules of liquid B enter the molecular vacuumcreated at area G by the vaporization of liquid A under the pressure system of .76 millimeter and temperature of 300 F., said molecules cannot exist in the liquid phase, and hence they immediately and completely vaporize; the process is continuous as successive molecules (solid circles) of liquid B reach and enter the molecular vacuum created by the continuous opposite flow and vaporization of liquid A at area G.

In this system, contrary to ordinary distillation the fractionation depends not only upon the relation between the vapor pressure of the liquids involved but also upon the differences of their molecular weights. Under a high vacuum the intra molecular spaces are greatly increased and thus offer an open path for molecules to pass between molecules and thus prevent collision which might result in a condensation. This molecular eiect in vacuum on vaporization of liquids is maintained in equilibrium not only by the continuous interilow oi' liquids of high molecular weight into vacuum molecular volumes induced by the vaporization of the low-molecular-weight liquid, but also by the fact that the escape of molecules from the liquid to the vapor phase is much less than the rate at which the molecules in the liquid phase arrive at the surface of the liquid for vaporization.

As an example, let us take the vaporization of a fuel oil of a molecular weight of 200 by a liquid such as methanol having a molecular weight of 32. Methanol has a boiling point oi' 147 F.; 32 lbs. of methanol will occupy 359 cu. ft., wherefore 1 lb. will occupy 11.2 cu. it. or 19,353 cu. in. As the gravity of methanol is 47.1 A. P. I., 1 gallon will weight 6.596 lbs.; therefore 1 lb. of liquid methanol will occupy 35 cu. in., or the expansion oi' liquid volume to vapor volume is 553 times. Therefore the pressure in the molecular volume of liquid methanol will be reduced to very close to` 1.4 millimeters. The liquid fuel oil molecules entering area G, and preheated to a temperature of 450 F., cannot remain in liquid phase under a pressure of 1.4 millimeters, hence they immediately proceed to vaporize as explained above, concomitantly with the vaporization of the methanol molecules.

In the actual operation or commercial application of this new process, we can examine Fig. 2 wherein I is a pipe still, heated externally, in which leg 5 is connected with lower leg 4 by means of a connection 3. The high-molecular- Weight liquid enters leg l through pipe 2, and the low-molecular-weight liquid (which is to be used as a means for vaporization) enters leg 4 through pipe I, and the vapors oi' both liquids escape from still I5 to pipe 'I which is connected to reaction chamber I 0, which chamber is connected with gas heater B through pipe connecion 8.

One or more inert gases enter gas heater 6 through connection 9 and are heated to a temperature higher than the temperature of the vapors entering I0 through still connection l. The vapors from the still commingle and mix intimately with the heated inert gases in the reaction chamber I0. The products of the reaction escape from the upper portion of chamber I0 through connection II and can be subjected to further treatment as desired. Any portion of the vapors entering chamber III through connection I and which are not reacted in said chamber, escape from the bottom of chamber I0 throughconnection I2 where they can either be led to storage through connection I 4 or passed back into still I5 through connection I3 and pipe 2 for further or additional heating.

In operation, still I5 is heated to the proper temperature and then the low-molecular-weight liquid, ilowing through I, enters the near end of leg 4 and vaporizes therein. The area of molecular vacuum having been established by said vaporization in leg-4 at approximately its midpoint, and the entire system having been heated to operating temperatures, the high-molecularweight liquid to be vaporized is introduced into leg 4 through pipe 2 and escapes from the open end of said pipe at the farther end oi leg I. whereupon said liquid ilows back to said molecular volume area Where it is vaporized concomitantly with the low-molecular-weight liquid.

It is essential that the high-molecular-weight liquid be heated above the boiling point of the low-molecular-weight liquid, but to a temperature which is lower than the cracking point of any of the liquid constituentsof said highmolecular-weight liquid. Inert gases are preheated in still 6 to temperatures above that of any of the vapors issuing from still I5. When the vapors from the still meet the heated inert gases in chamber I0, a reaction takes place resulting in the production, in the vapor state, oi' products different from those originally existing in the high and low molecular weight liquids. These products, together with the inert gases, escape from chamber I0 through connection II, and thereafter all inert gases may be separated from said reaction products and recycled back through connection 9 to be preheated again in i for reintroduction into chamber I0 for reuse in reacting upon vapors entering chamber I0 from still I5.

The controlling factor in the application oi.' this new process, and invention, is that there shall be two liquids, the difference in the molecular weights of which shall be appreciable. The liquid having the higher molecular weight (the one to be vaporized and distilled) is preheated to a critical temperature while passing along a substantially horizontal plane in one direction through the channel established by tube C, or the area occupied by the liquid having the lower molecular weight, and then the molecules of this higher-molecular-weight liquid are caused to flow in the opposite direction in said established channel and along substantially the same horizontal plane into the high molecular vacuum area produced by the vaporization of the liquid of low molecular weight at said critical temperature. The character of the liquid to be vaporized, and the products desired to be obtained therefrom, are also controlling factors in the selection of the vaporizing-liquid having the lower molecular weight. For instance, high boiling petroleum oils, vegetable oils, or animal oils,can be completely vaporized in the above manner by means of the vaporization of acetone, methanol, or any;

other liquid havingv a molecular weight which is appreciably lower than the molecular weight of the liquid to be vaporized. In some cases where immiscibility is required, it will be necessary to choose a low-molecular-weight vliquid for the vaporizing medium which will not be soluble in the condensates later produced from the vapors of the high-molecular-weight liquid. In other cases where miscibility is desired, such solubility may take place. The ratio or proportion in the feeding to the still of the two liquids, will closely approach the ratio of their molecular weights. and the liquid of low molecular weight preferably should have the lowest heat of vaporization possible in the interest of economy in conducting the process. It will .be understoodthat after the complete vaporizationof both liquids has taken place at the reduced pressure area G, the combined vapors are lead from said area through the ilue F to any suitable point for cracking and/or fractionation as well as condensation, or any other purpose as desired. Whereas in the foregoing the cracking has been referred to, in the interest of simplicity, as heating the vapors with an inert gas, it is intended that other gases, vapors, means, apparatus, methods, procedures, instrumentalities and/or iniluences are contemplated and may be used as substitutive of the specific inert gas and equipment disclosed herein.

It is obvious that those skilled in the art may vary the details of construction and arrangements of parts constituting the apparatus, as well as vary the steps and combinations of steps constituting the process without departing from the spirit oi this invention, wherefore it is desired not to be limited to the exact foregoing disclosure except as may be required by the claims.

What is claimed is:

l. The method of completely vaporizing a liquid, which comprises flowing a body of a different liquid in a layer in one direction along a substantially horizontal plane in an established channel, said different liquid having a molecular weight which is less than that of the liquid to be vaporized; heating the iiowing layer of the diiferentv liquid to boil the same. said heating being conducted at a pressure above atmospheric; conducting as a stream in the established channel the liquid to be vaporized in the same direction as but beyond the flowing and boiling layer of the diierent liquid; pre-heating said conducted stream by the same source of heat utilized Afor boiling said different liquid; flowing the preheated stream of the liquid to be vaporized in a layer in the opposite direction along substantially the same horizontal plane in the established channel towards the layer of the different liquid; heating the owing layer of the liquid to be vaporized to a temperature which is below that of the decomposing point of any of its components but which is above the boiling point of said different liquid; contacting in the established channel the layer oi' the heated liquid to be vaporized with the layer of the boiling different liquid; maintaining a xed ratio of feed between the quantities of the two liquids; maintaining a free vapor space above the owing liquid layers; and removing vapors from the vapor space.

2. The method of completely vaporizing a liquid,

which comprises flowing a body of a different i i different liquid tc boil the same, said heating being conducted at a pressure above atmospheric; conducting as a stream in the established channel the liquid to bevaporized in the same direc- `tion as but out of contact with and beyond the flowing and boiling layer of the diilerent liquid; pre-heating said conducted stream by the same .source of heat utilized for boiling said different liquid; flowing the pre-heated stream lof the liquid to be vaporized in a layer in the opposite direction along substantially the same horizontal plane in the established channel towards the layer of the different liquid; heating the owinglayer of the liquid to be vaporized to a temperature which is below that of the decomposing point of any of its components but which is above the boiling point of said diilerent liquid; contacting in the established channel the layer of the heated liquid to be vaporized with the layer of the boiling different liquid; maintaining a fixed ratio of feed between the quantities of the two liquids; maintaining a free vapor space above the flowing liquid layers; and removing vapors from the vapor space.

3. The method of completely vaporizing a liquid which comprises flowing a body of a different liquid in a layer in one direction along a substantially horizontal plane in an established channel, said different liquid having :a molecular weight which is less than that of the liquid to be vaporized; heating the flowing layer of the different liquid to boil the same, said heating being conducted at a pressure above atmospheric; conducting as a stream in the established channel the liquid to be vaporized in the same direction as but over, out of contact with, and beyond the owing and boiling layer of the different liquid. pre-heating said conducted stream by the same source of heat utilized for boiling said diierent liquid. flowing the preheated stream of the liquid to be vaporized in a layer in the opposite direction along substantially the same horizontal plane in the established channel towards the layer of the different liquid; heating the flowing layer of the liquid to be vaporized to a temperature which is below that of the decomposing point of any of its components but which is above the boiling point of said different liquid; contacting in the established channel the layer of the heated liquid to be vaporized with the layer of the boiling different liquid; maintaining a iixed ratio of feed between the quantities of the two liquids; maintaining a i'ree vapor space above the flowing liquid layers; and removing vapors from the vapor space.

4. A still for completely vaporizlng a liquid, comprising means for flowing a body of a different liquid in a layer in one direction along a substantially horizontal plane in an established channel, the different liquid having a molecular weight which is less than that of the liquid to be vaporized: means for heating the owing layer of the different liquid to boil the same: means for conducting a stream of the liquid to be vaporized in the same direction as but to a point beyond the flowing and boiling layer of the different liquid, said conducting means being so located that its contained stream will be substantially in the same established channel and will be preheated by the heat oi said heating means, said conducting means adapted to direct its preheated stream into the same substantially hori'fontal plane for flowing as a layer in the opposite direction towards and contacting .the boiling layer of the dinerent liquid; said means for heating including adof relatively large diameter, a pair of liquid conducting pipes entering said tube adjacent one of its ends, said rpair of pipes being each of relatively smaller diameter, one of said pipes for conducting the liquid to be vaporized, the other pipe for conducting a different liquid having a molecular weight which is less than that of the liquid to be vaporized, the ends of said pipes in said tube being open and directed for discharging their contained liquids directly againsty an inner surface of said tube, the pipe for the different liquid terminating closely adjacent its entry into said tube, the pipe for the liquid to be vaporized extending in said tube well beyond the end of its companion pipe, means for heating said tube and its liquid contents, and a vent at the other end of said tube for the discharge of the valpors created in said tube.

` BERNARD ORMONT.

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

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