US1703419A - Method and apparatus for distillation - Google Patents

Description

Feb. 26, i929,

T. A. w. DWYER METHOD AND APPARATUS Fon DIs'rILLATIou Filed Jan. 20, 1926 2 Sheets-Sheet Snom/toa @Hoz/nc Febv 26, 1929. 1,703,419

T. A. W. DWYER METHOD AND APPARATUS FOR DISTILLATION Filed Jan. 20. 1926 2 Sheets-Sheet 2 Patented Feb. 26, 1929.

UNITED STATES THOMAS A. W. DWYER, OF PASSAIC, NEW JERSEY, ASSIGNOR OF SEVEN-SIXTEENTHS TO HANS 0. SCHUNDLER, 0F MADISON, NEW JERSEY, TWO-SIXTEENTHS T0 WILLIS H, BOTSFORD, 0F NEW YORK, N. Y., AND ONE-SIXTEENTH TO ARCHIMEDES J.

JAMES, OF NEW YORK, N. Y.

PATENT OFFICE.

METHOD AND APPARATUS FOR DISTILLATION.

Application. led January 20, 1926. Serial No. 82,440.

The invention relates to the distillation of volatile carrying materials, such as oil shale, coal, wood, etc., and has for its primary object to enable fractionated vapors to be produced in stratified formation in a still chamber, and drawn off therefrom in such condition.

Another object of the invent-ion is to react upon the vapors while contained within the still chamber as aforesaid, in such a way as to obtain a direct yield of compounds which heretofore have only been obtained by processes carried out separately subsequent to distillation.

Further objects and advantages of the invention will be in part obvious and in part specifically pointed out in the description hereinafter contained, which disclosure, however, is to be considered merely as illustrative of the principles of the invention. In the drawings- Fig. l is a longitudinal sectional view of a still constructed in accordance with the invention.

Fig. 2 is a transverse section taken along line 2-2 of Fig. 1.

Fig. 3 is a diagrammatic view showing several stages of distillation, such as will ordinarily be employed in practicing the invention.

The general type of still employed in practicing the present invention is similar to the one disclosed in my prior application, Serial Number 7 32,17 7 filed August 15, 1924, and entitled Rotary still.

The still employed is of the horizontal type and is rotatably mounted within a suitable oven 1 as by means of a suitable number of roller bearings 2 and 3, engaging rings 4 and 5 respectively located near the entrance and delivery ends of the still casing 6. The still is rotated in any suitable manner, as by means of a gear 7, at its entrance end near the ring 4, and engaging a pinion (not shown).

The material to be distilled is suitably fed into the still casing, for example, by a hopper 8 communicating through a conduit 9 at its lower end with the entrance end of the still, the material being pushed forward through conduit 9 by some such device as a reciprocable piston 10 mounted therein.

I have found that by the use of a still casmg 1n the form of the frustum of a pyramid, the vapors glven olf may be caused to assume a stratified formation in the upper portion of the still easing, the rotar motion of the still causlng the materials to e progressively fed through the casing and turned over in such manner as to be uniformly heated. The still casing 6 1s rotated at slow speed, for example, two or three revolutions per minute, and the material fed in through conduit 9 falls to the bottom side of the casing into a pile of the shape shown in F 1g. l. As the still rotates, owing to its polygonal cross section, the mater1al remains substantially stationary with regard to the side Walls until the bottom side wall has turned upward to an angle greater than the angle of repose of the material being treated; at this point the material shifts quite suddenly with respect to the walls of the still, with the result that such material is well turned over, the parts of the material which prevlously were innermost, falling downwardly into contact with the then bottom side of the still, and the arts of material which previously had been 1n contact with the side walls and therefore subjected to the most intense heat, dropping down on top of the body of the material. Thus the rotary motion of the still produces constant shifting or turning over of the material, which insures uniform heating thereof, and prevents the burning of portions of such material against the side walls of the still, such as would occur, for example, in a circular or conical still, where the body of material being treated would tend always to slip down the curved walls of the still without the different parts of the material shifting'to any substantial extent with regard to each other. The continual shifting of the material which is brought about by the form of still above described also produces dependable and sharply defined fractionation, and the vapors it has been found stratify evenly in the upper part of the still, from whence they may be withdrawn as they are formed in such condition as to promote their separation.

The forward feed of the material through the still is brought about merely by the natural forward movement caused by the rotation of the still, the piston being operated only at sufficient speed to replace the material in the conduit 9 as it gradually falls oft into the casing 6.

The material passes along the casing 6 in the manner above described to its delivery end, from whence it may be educted as b a suitable conduit 11 in a fixed housing 12. he fractionated vapors may be drawn off through a suitable pipe 13 connected to housing 12 at the deliveryend of the still, from whence the vapors may bey led to suitable separating apparatus, or subjected to other desired treatment which need not be described herein.

For most purposes I have found the hexagonal shape illustrated to be advantageous, the use of a still in the shape of a many-sided polygon approaching too nearly circular cross section to adequately shift and turn over the material for best results, while the use of a three or four-sided pyrainidal shape for some purposes tends to' create too much dust within the still, although it will serve to mix the materials thoroughly for uses where the dust is not objectionable.

The temperature within the still casing 6 is controlled by a pyrometer 25 inserted through an opening 26 in the housing 12, into the fractionated vapors, the amount of heat supplied by the oven being regulated in any suitable manner (not illustrated) from the pyrometer.

According to the speed of rotation of the still, the rate of passage therethrough of the material may be adjusted as desired, which in combination with the temperature control above mentioned, makes the apparatus properly adjustable to variable conditions of operation. The material will be subjected to heat treatment for about thirty minutes, for example, in passing through a still casing twenty feet long, tapering from a diameter of three feet at its entrance end up to five feet at its delivery end, with the casing rotated at a speed of two revolutions per minute.

For most purposes the entrance end of the still will be suiciently sealed as regards the hopper 8 and conduit 9, by the material being fed through. The entrance end of the still casing may also be suitably sealed to provide a fluid-tight joint, as by means of an end plate 14 which is fixed on the walls of the conduit 9 and carries a gland 15 holding packing material such as asbestos contained within member 14. As shown, a ring 17 is mounted on the entrance end of casing 6 to support the members 4 and 7 above described as well as to turn truly within the gland 15 and packing material 16. At its delivery end the still may be sealed by packing 19 and the water seal indicated diagrammatically at 18 for the conduit 11.

I have also found that the process is improved bythe introduction of nitrogen in measured quantities into the distilled vapors, it being unnecessary to employ pure nitrogen for this purpose; the amount of nitrogen contained in air is suiicient to enable air to be used, the air being admitted in a proportion of about 30% by volume (at ordinary temperatures and under pressure of about 25 lbs. per sq. in.) of the material to be distilled, although the percentage of air employed of course will vary with the leanness or richness of the material being treated. As shown in Figure 1, for example, compressed air may be admitted through a pipe 27 leading into the entrance end of the still casing. As will be noted from Fig. 1, the air or nitrogen admitted through pipe 27 diffuses throughout the voids between the particles of material being treated, and hence does` not have such velocity as to disturb the vapors subsequently educted from the material being treated; furthermore, although the air or nitrogen is preferably admitted through pipe 27 under some pressure to insure its positive injection into the material being treated, the amount of air or nitrogen admitted is so controlled as not to raise the pressure within the still above the proper operating value. In other words,

even if air or nitrogen be admitted, the vapors, nevertheless, are still drawn o' from the upper part of the still casing, maintaining a negative pressure within the still. The nitrogen combines with the vapors to some extent forminoP nitrogenous values such as pyridine, memers of the aniline and quinoline series, which heretofore have been isolated only by separate processes carried out subsequent to fractionation.

As illustrated in Figure 3, ordinary materials, such as shale or coal, will usually be distilled in three stages, the temperature of the still casing within the first stage running up to about 750o F., the temperature of the second stage up to about 900O F. and that of the third stage up to about 1250o F. The construction of the still employed is the same as above described in connection with Figure 1, exceptthat the housing 12a at the delivery end of the still of the first stage delivers the` material to the conduit 9b of the second stage instead of to a water seal, while the housing '12b of the second stage delivers the material to the conduit 9c of the third stage. ln the distillation of oil shale, for example, as abovel described, olenes will be driven olf in the first. stage, and will stratify in the upper part of the still casing.

The vapors driven out during the second stage, will contain admixed na hthenes, polymetylenes and other compoun s, the nitrogen of the injected air reacting with the vapors to form compounds such as hexamethylene, amines and other amido groups of these naphthenes and polymethylenes, which compounds heretofore have been isolated only by separate processes carried out subsequent to distillation.

In the third stage, compounds of the aromatic series, such as pyridine and different members of the aniline and quinoline series, will be obtained, which compounds I believe not to have been heretofore obtained as the direct yield of a distillation process.

Fig. l is intended to illustrate in al rough way the travel of the stratified vapors through the still casing, the lighter vapors coming oil' first traveling upwardly toward the top of the casin in a path inclined to Ward the outlet con uit and the heavier vapors being driven otl successively at points along t-he path of travel. of the material through the casing.

lVhile a specific example of the practice of the invention has been describedl` it will be obvious that many changes may be made therein without departing from its principles as set forth in the appended claims.

I claim:

1. The process of distillation in a heated still of the horizontal type which comprises feeding carbonaceous material containing substances which will give off a plurality of volatiles of different densities when heated to successively hi her temperatures, through the still, while shifting the material about to heat it so uniformly as to distill ofl different volatiles successively at points spaced along the length of the still, and maintaining such undisturbed conditions in the upper part of the still as to produce stratified vapors in the upper part of the still.

2. v-The process of distillation in a heated still of the horizontal type which comprises feeding carbonaceoiis material containing substances which will give off a plurality of volatiles of different densities when heated to successively higher temperatures into t-lie still, rotating said still to advance the material along the still and continuously turn over the material by such rotary motion to heat it so uniformly as to distill off different volatiles successively at points spaced along the length of the still, and maintaining such undisturbed conditions in the upper part of the still as to produce stratified vapors in the upper part of the still.

3. The process of distillation in a polygoiial heated still of the horizontal type which comprises heating carbonaceous material containing substances which will give off a plurality'of volatiles of different densities when heated to successively higher temperatures into the still, rotating the still to advance the material therethrough and heat the same so uniformly as to distill off' different volatiles successively at points spaced along the length of the still, and maintaining such undisturbed conditions in the upper part of the still as to produce stratified vapors in the upper part of the still.

4. The process of distillation in a heated still ,of the horizontal type which comprises feeding carbonaceous material containing substances which will give off a plurality of volatilesof different densities when heated to successively higher temperatures, through the still, while shifting the material about to heat it so uniforiiil as to distill off different volatiles successively at points spaced along the length ot' the still, and maintaining` sucli undisturbed conditions in the upper part of the still as to produce stratified vapors in the upper part of the still and introducing a substantial proportion of nitrogen into said still.

5. The process of distillation in aheated still of the horizontal type which comprises feeding carbonaceous material containing substances which will give off a plurality of volatiles of different densities when heated to successively higher temperatures into the still, rotating said still to advance the material along the still and continuously turn over the material by such rotary motion to heat it so uniformly as to distill off different volatiles successively at points spaced along the length of the still, and maintaining such undisturbed conditions in the upper part of the still as to produce stratified vapors in the upper part of the still and introducing a substantial proportion of nitrogen into the still adjacent its entrance end.

6. The process of distillation in a heated still of the horizontal type which comprises feeding carbonaceous material containing substances which will give off a plurality of volatiles of different densities when heated to successively higher temperatures, through the still, while shifting the material about to heat it so uniformly as to distill off different volatiles successively at points spaced alon the length of the still, and maintaining suc undisturbed conditions in the upper part of the still as to produce stratified vapors in the upper part of the still and introducing additional gas into the still to react with vapors contained therein.

7. A distillation apparatus comprising a polygonal rotary still casing of the horizontal type, means for feeding carbonaceous materials containin substances which will give off a plurality ofg volatiles of different densities when heated to successively higher temperatures, into said casing, means for rotating said casing to advance the material therethrough and heat the same so uniformly as to distill ofll different volatiles successively at points spaced along the length of the still, and produce stratified vapors in the up er part of the still casing, means for introdhcing a substantial proportion of additional gas into said casing, and a conduit associated with said casing adapted to draw off vapors from the upper part of the delivery end of said casings.

8. A distillation apparatus comprising a polygonal rotary still casing of the horizontal type, means for feeding carbonaceous ma.- terials containing substances which will give oilI a plurality of volatiles of different densities when heated to successively higher ternperatures, into said casing, means for rotating said casing to advance the material therethrough and heat the same so uniformly as to distill off different volatiles successively at points spaced along the length of the still, and produce stratified vapors in the upper part of the still casing, means for introducing a substantial proportion of additional gas into the entrance end of said casing, and a conduit associated with said casing adapted to draw off vapors from the upper part of the delivery end of said casing.

9. A distillation apparatus comprising a rotary still casing of the horizontal type and in the shape of a frustrum of a pyramid, means for feeding carbonaceous material containing substances which will give off a plurality of volatiles of diHerent densities when heated to successively higher temperatures, into the smaller end of, said casing, means for rotating said casingto advance the material therethrough While shifting the material about to heat it so uniformly as to distill off different volatiles successively atpoints spaced along the length of the still, to produce fractionated vapors in the upper part of the still casing, means for introducing a substantial proportion of additional gas into the entrance end of said casing, and a conduit associated With said casing adapted to draw ofi' vapors from the upper part of the delivery end of said casing.

In testimony that I claim the foregoing. I have hereunto set my hand this 8th day of January, 1926.

THOMAS A. IV. DWYER

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