US1288711A - Method of and apparatus for distilling petroleum and the like. - Google Patents

Description

L. O. SHERMAN. METHOD 0F AND APPARATUS FOR DISTILLING PETROLEUM AND THE LIKE.

' APPLicATIoN EILD :vm/.15, 1917.

1,288,71 1. Patented Dec. 24,` 1918.

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L. 0.'SHERMAN. METHOD 0F AND APPARATUS FDR DISTILLING PETROLEUM AND THEVLIKE.

. APPLICATION FILED NOV. 1'5, 19111 1,288,71 1 Patented De@.24,1918.

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ra 'ca/MENSER" /I/A//ll 83* M'Qywm- TQM I n L. O. SHERMAN. METHOD 0F AND APPARATUS FOR DISTILLING PETROLEUM AND THE LIKE.

APPLICATION FILED NOV. I5, i917.

Patented Dec. 24, 1918.

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LAYTON 0. SHERMAN, F EAST 'QBICAGQ INDIANA.

METHOD OF AND APPARATUS FOR DISTILLING PETROLEUM AND THE LIKE.

' To all idiom t may concern.-

`Be it known that I, LAY'roN O. SHERMAN, .ay citizen of the Unitedv States, residing at East Chicago, in the county of' Lake and State of Indiana, have invented certain new and useful Improvements in Methods of and Apparatus for\Distilling Petroleum and the like, of which the following is a specification.

This invention relates to the distillation of oils for the purpose of obtaining therefrom a maximum amount ofloW-boiling hydrocarbons of the motor-fuel type. I

According to the invention the low-bolling portions are permitted ,to proceed to the condenser as formed while the higher-boiling fractions are separated from the vapors and reheated under such conditions as to effectively crack them.

The present invention is an improvementon those covered in my prior patent No. 968,088, dated Aug. 23, 1910, and my application fled April 24, 1916, Serial No. 93,180.

, -It has been found that very efficient cracking of the higher-boiling portions can be accomplished at a relatively low temperature if the period of heating is correspondingly prolonged. In the operation of my invention, a portion of the body of oil from the still proper and -the higher-boiling fractions separated from the vapors in a return-condenser are passed through a long coil wherein-they are subjected to a temperature eX- ceeding that of the body of the oil in the still and thereby decomposed or cracked.` Dueto the extended duration of this step, however, the cracking temperature can be materially reduced. The vapors generated in this long coil mingle with any vapors evolved from the body of oil in the still and pass to the return-condenser. The lowboil ing portions persist as vapors throughout the course of travel through the return-condenser while the -higher-boiling portions are condensed and conveyed to the coil for furthe!l heating at the increased temperature with a portion of oil from the still.

The apparatus in its preferred form comprises a still of the ordinary cylindrical form having a fused metal false-bottom upon which the oil rests, a coil located in the furnace beneath the still or submerged in the fused false-bottom, so as to be subjected to a greater temperature than the body of oil in the still and open at its upper end to the vapor-space of the still, a separating-tower or return-condenser to which the vapors are Patented Dec. 24, 1918.

Application filed November 15, 1917. Serial No. 202,160'.

conducted from the still and Awherein the higher-boiling portions are condensed and thus separated from the lower-boiling .por-

tions, a conduit for conveying oil from the still to the lower end of the coil and conduits for conveying the condensed higher-boiling portions from various levels of the separating-tower to such lower end of the coil. If the coil is located in the furnace, it is preferably jacketed and the jacket filled with molten material, for instance, fused lead or lead-alloy. Means for'separating out any carbon from the oil is interposed in the path of the oil flowing to the coil.

The invention will be better understood by reference to the accompanying drawings, wherein- Figure 1 shows a vertical longitudinal section of the preferred form of apparatus;

Fig. 2 shows a vertical section along the line II-II of Fig. 1;

Fig. 3 is a sectional View of one of the manifolds and neighboring details;

Fig. 14; is a sectional view of one of the pipe-joints adjacent another manifold;

Fig. 5 is a fore-shortened longitudinal section of a modified form of apparatus; and

, Fig. 6 is a transverse vertical section along the line VI-VI of Fig. 5.

In the form shown in Figs. 1. and 2, the cylindrical still 1 is mounted on a suitable furnace 2 suiiiciently high above the fire-box of the latter to accommodate a coil or series 0f coils 3. Each of these coils comprises e an inner pipe 4 for conveying the products top may beapplicd and the molten material poured in, or the annular chamber may be filled in any other suitable manner.

The coils 3 ext-end preferably from one end of the furnace tothe other, a distance of, say, 30 feet, and thc bends, of which there may be any suitable number per coil,

.may be conveniently supported in pockets '8 provided in the end-walls` of the furnace. l1.) Additional support is desirable at or near the middle pf the length ofthe pipes and for this purpose brick or other supports 9 through openings in which the pipes pass are provided midway the length of the furnace. yThese supports may be carried by a protected steel cross-beam 10.

Except at their ends, the coils 3 are continuous or jointless, all return-portions thereof consisting of smooth bends as shown in Fig. 1. The upper ends of the coils, the

`latter lying preferably but not necessarily upper manifold 13 mounted transversely of the front furnace-wall, and the ends of this manifold are connected by pipes 14, 15 with the vapor-space 16 above the oil 17 in the still.

Adjacent the upper ends of the coils, the jacket is preferably provided with some means for permitting expansion and contraction of the fused metal between the pipes 4, 5. In the form indicated in Fig. 4, such means consists of a stand-pipe 18 welded or otherwise attached to the upper side of pipe 5, in which the molten metal may rise and fall. To prevent oxidation, a follower 19, comprising a disk of asbestos clamped between two disks of steel, floats on the metal in the well 18.

The furnace may be provided with any practicable number o f units of coils 3, twelve thereof being shown in Fig. 2.

The oil in the still 1 preferably lies over a fused false-bottom 2O of lead or lead-alloy or other suitable material. Pyrometers or other temperature-measuring devices 2 1 may be inserted in the oil and fused false-bottom of the still and in the coil 3, at convenient places, and a pressure-gage 22 is provided on the still.

Above the still 1 and connected thereto by a pipe 23 is a return-condenser 24. This 'condenser may be of the type shown and described in my prior patent and application above referred to. It may be of some other type, however, and in'some instances a tower of the well known'dephlegmator form maybe sufficient. It is desirable, however, that the tower be of such form and dimensions 'and offer such resistance to the iow of vapors therethrough that under the particular conditions of temperature, time and pressure of operation all products hav-v .ing boiling-points in excess of those of the low-boiling products desired, Vfor instance,

all which will not distil at or about 400 F.,

zones of condensation in the tower, according t0 their various degrees of volatility and such forms are therefore preferred. In Figs.

1 and 2, two of such towers are shown and they may be operated together in multiple or alternately.

The pipe 23 has two branches 25, 26, Fig. 2, leading to the bottoms of the two condensers 24 through elbows 27, 28. A fillingvalve 29 may be provided the pipe 23 as may also a shut-off valve 30. The passages to the return-condensers may be controlled by suitable valves such. as thatshown at 31. Pipe 32 conveys the uncondensed low-boiling products from the tops of the towers to a suitable condenser, not shown. Connected to the towers 2jr/at diametrically opposite points and at various heights are draw-o pipes 33;.39 for collecting the condensed higher-boiling portions. The number of vthese draw-off pipes will depend upon along the outside of and parallel .to the rear wallfof the furnace opposite the lower ends of the coils 3- and discharges the higherboi1- ing portions into such coils throughjet-pi es 48. These jet-pipes extend a considera le distance into the coils 3 for a purpose presently to be described. A check-valve 49 Fig. 2 is .provided in the manifold 47 between the connections thereof with the return-pipes 40-46 and the first ofthe 4jetpipes 48.

Connected to the still 1 just above the level of the fused-metal false-bottom 20 is an oiloutlet pipe 50 having branches leading to the upper ends of carbonfseparators 51 of which two are represented in the drawings.

-These may be operated in multiple but are preferably used alternately so that one may be cleaned while the other is in use. Suitable valves may be provided in the branch-pipes for this purpose. Forthe purpose of en- 'tirely shutting off the How of oil through of any suitable type, for instance, one with a baiiied interior arrangement, but I pre# fer a separator of the filter type using peb- ^bles or the like supported on trays and varying in 'lneness from coarse to qulte ne. some cases, a fine mineral substance such as fullers earth may be used near the end of travel of the oil through the filter. Oiloutlet pipes 54 are connected to the separators at or near their bottoms and convey the filtered oil to a manifold 55, which for su'bstantially the width of the furnace incloses concentrically the return-condensate manifold 47. Check-valves 56 are provided in the pipes 54. The opposite side of the manifold is connected by suitable welded joints (see Fig. 3) to the lower end of each of the coils 3, thev openings 57 of the manifold passage registering with the openings 58 of the inner pipes 4 of the coils 3. The jetpipes 48 of the inner manifold 47 extend through the passages 57,58 well into''the pipe 4, as indicated in dotted llines in Fig. 1. Oil from the carbon separators. 51 thus enters the coils 3 through the passages 57, (Fig. 8) 58 while the condensate from the return-pipes 40-46 yunder a head of .pressure is forcibly admitted to the coils 3 through the jet-pipes 48.

In case the feeding of the oil from the lcarbon-separator to the coils 3 becomes sluggish, a circulating-pump 59 is cut in. This pump takes in oil from the carbon-separator- 51 through a valved pipe 60 and discharges it through a pipe 61 into the manifold 55. The pipe 61 is provided with a swingingcheck 62 and a pressure-gage 63 is located on the pipe between the valve 62 and the manifold 55. To permit filling of the still and the coil system with oil by means of the pump 59 a valved oil-feed pipe 64 is connected to the intake side of the pump.

In operating, a shallow puddle of the fused material composing the false-bottom 20 is formed in the still l and oil, which may be crude petroleum, crude-oil residue, or a middle-distillate, is supplied to the system either through the valve 29 in the vaporline 23 or by means of the ump 59 through pipes 64 and 61 and mani old 55, until the still is, say, four-fifths full, the vvalves 1n pipes 53 and 60 and the valve 30 being meanwhile closed, of course. The fillingvalve 29 or the valve in the pipe, 64 as the case may be, is then closed and the valve 52 opened. The jackets of the coils 3 are filled with molten lead-alloy or other suitable fused material through the filling-plug 7. The furnace is then gradually heated up, preferably until oil in the still vaporizes. If the material operated upon is a crude-oil, the valves leading to the tower 24 are opened from the outset and the vapors comprising the low-boiling fractions of the oil are allowed to proceed through the tower to the Condenser at once. When the low-boiling fractions have passed oif and the gravity of the distillate drops below that permissible v or desirable, the valve 30 is closed or partly closed to produce pressure in the still 1. In case middle-distillates are being treated, the' Valve 30 is closedA or partly closed at the start so that pressure in the still develops at once as the temperature of the oil 17 rises. Vaporization is effected at as low temperatures as possible, but toward the close of the operation on a batch, it may be necessar to run as high as 750 F.

When the-pressure on the vapors in the still has risen to a suiicientheight, say 25 pounds, the valve 30 in the vapor-pipe 23 is opened a little to enable some of the `my prior application, but -I prefer to operate in-such manner that the pressure is jlust reduced to atmospheric when thevapors reach the main condenser. This can be accomplished by proper' dimensioning and construction of the towers and regulation of lthetemperature of operation and the pressure in the still,--conditions which must be determlned by experiment in each particular case. As the temperature of vaporization of the mass of oil rises, the pressure in` the still must be progressively increased, slightly, to maintain the yield of low-boiling condensate uniform so far as possible both in quantity and gravity.

The higher-boiling fractions, say of less than 50 B. gravity, are condensed in the tower 24 at one level or another, are collected by the draw-olf pipes 33-39, conveyed tothe return-pipes 40-'-46 and pass into the collecting manifold 47 which 'soon fills in the course of operation. This condensate also collects in the vpipes 40-46, which are veritable stand-pipes, until the gravity pressure on the portion in the manifold 47 is sufficient to overcome lthe pressure inthe pipes 4, which pressure' is at' the start the same as that insthe vapor-space 16 of the still into which the pipes 4 open,fwhe1;eupon the check-valve 49 is opened and the condensate flows through the jet-pipes 48 into the pipes 4. The temperature in the pipes 4 is somewhat higher than that of the with considerable force, as jets.

for the materialbeing` treated as the time of cracking is considerably prolonged by the lenlgth of the coils.

he temperature in the cracking-coils 3 increases, of course, as the vaporizing temperature in the still increases. The average range of cracking-temperature is'frorn 675O F. to 750 F. and the first 35 per cent. of a batch of oil should be converted into lowboiling fractions of desired gravity, say 58"-63o B., at temperatures not exceedlng 715 F. The-temperature ofthe body of oil in the still durin this period may run between 650 F. and 00 F.

As the cracking occurs in the coils 3, the pressure therein is considerably increased and the gaseous products are driven out of the upper end of the pipe 14 into the vaporspace 16 of the still where they mingle with the vapors thereof and pass to the returncondenser where the highand low-boiling ortions are separated as before, the former eing collected in the pipes 33-39 and returned to the superheating coils 3, while the low-boiling portions pass on to the main condenser.

When the apparatus is properly adjusted as to temperature and pressure and therefore speed of operation, the vertical portions of pipes 40-46 are progressively f cooler asthey connect with the higher zones of the return-condenser. That is, pipe 46 is hotpipe 45 is not quite so hot as 46, and

so on, pipe 41 being only slightly warm while pipe 40 is cool. Under such conditions it is evident to the operator that the system is now gas-bound vand that the desired products are being-recovered.

In case of suspension ofopera'tion, the valve 52 which controls the passage of oil tothe carbon-separator 51 is closed. Thereby no further oil is fed into the coils 3 although the high-boiling condensate will continue to flow into the coils from the return-condenser for a considerable length of time-,in fact until the still is practically cool. By this means, the inner pipes 4 of the, coils 3 are scoured by the condensate so long as there is any lsubstantial heat in the 'furnace and there is nol chance for formation of coke therein.

In the form of apparatus shown in Figs. 5 and 6, the superheating or cracking-coil is submerged n the fusedfalse-bottom.

The arrangement is in part similar to that shown in my prior application. However, I have found it desirable to connect the pipe or pipes which return the high-boiling condensate to the botg/r of the coil instead of to one of the upperliturns.

As in the case of the form shown in Figs. 1 and 2, oil from the still is introduced into the cracking coil along with the return condensate after being irst subjected to a carbon-separating step. rIhe How of oil through the filter 71 takes place in an upward direction in the form shown, oil entering the separator at or near the bottom through a valved pipe 7 2 and discharging at or near the to into a pipe 7 3 supplied with a check-valve 4 and which leads to a manifold 75 similar in construction to the manifold 55 in Figs. l and 2. The inner concentric manifold which-supplies the returned condensate from the return-pipes 76 to the jet-pipes in the submerged coil is indicated at 77. The jet-pipes, of which there are preferably two, are shown at 78. The pipe `7 9 connecting the manifold 75 with the coil 70 has two branches, one connected with the,

opposite sides of the still and pass into the vapor-space 82 of the still through pipes 83 at the two ends of the coil. As in the rst form of apparatus shown, the jet-pipes 78 extend a considerable distance into the pipe sections 80, 81 for the purpose hereinbefore described.

The operation of this apparatus is substantially the same as that described for the construction shown in Figs. 1 and v2 and further description is not thought necessary.

It will be obvious that many changes in the details of construction and operation may be made without .departing from the spirit and scope of my invention.

' I claim:

l. The method of distilling oil which consists in vaporizing va portion thereof, separating from the vapors the higher-boiling portions, subjecting the latterfmixed with a portion of oil vfrom the still to a prolonged heat at a low cracking temperature whereby the still to a temperature in excess of that.

of the vaporizing temperature of the oil in the still and condensing the low-boiling products.

3. The method of distilling oil to obtain low-boiling products, which comprises heating the oil under pressure to vaporize a portion thereof, condensing the higher-boiling portions of the distillate, heating said condensed higher-boiling portions together with a portion of oil from the still to a temperature above that of the oil and at a pressure above that of initial vaporization and condensing the low-boiling products.

4. The method of distilling oil Which confrom said still to the othereud of said pipe,

and means for conveying the higher-boiling portions from said return-condenser to said other end of the pipe.

6. Apparatus for distilling oil, comprising a still, a coil open at its upper end to the vapor-space of the still, a return-condenser adapted to receive the vapors from said still, means for heating said still and said coil, the latter to a greater temperature than the oil in the still, means for conveying oil from said still to the lower end of said coil, and means for conveying the higherboiling portions from said return-condenser to said lower end of the coil.

7. Apparatus for distilling oil, comprising a still, a furnace beneath said still, a return-condenser adapted to receive the vapors from said still, a coil beneath the still having its 'upper end open to said vapors, means for conveying oil from said still to thelower endof said coil, and means for conveying the higher-boiling portions fromi said return-condenser to said lower end of the coil.

8. Apparatus for dist-illing oil, comprising a still, a return-condenser adapted to receive the vapors from said still, a pipe open at one end to said vapors, means for heatingA said still and said pipe', the latterto a greater temperature than that of the oil in the still,

- a conduit for conveying oil from said still to the other end of said pipe, means interposed in said conduit for separating carbon from the oil as it flows to said pipe, and `means for conveying the higher-boiling portions from said return condenser` to said other end of the pipe.

9. Apparatus for distilling oil, comprising a still, a furnace beneath said Still, a return-condenser adapted to receive the vapors from said still, a coil of pipe beneath the still having its upper end open to said.

vapors, a conduit for conveying oil from said still -to the lower end of said coil, means interposed in said conduit for separating carbon from the oil as it flows to said coil, and means for conveying the higher-boiling portions from said return condenser to saidV lower end of the coil.

10. Apparatus for distilling oil, comprising a still, a fused-metal false-bottom in said still, a pipe open at one end to the vaporspace' of the still, means for heating said still and said pipe,the latter to a greater temperature than the oil in the still, means for separating the higher-boiling portions from the vapors from said still, means for passing oil from the still immediately above the fused false-bottom into the other end of said pipe, and means for conveying the separated higher-boiling portions to said other endof said pipe. y

1l. Apparatus for distillin'g oil, comprisin a still, a return-condenser connected therewith, a furnace beneath said still, a

jacketed coil beneath the still having its upper end open to the vapor-space of the still and the jacket thereof being filled with molten material, means for eonveyingvoil from p said still to the lower-end of said coil), and means for conveying'the higher-'boiling portions from said return-condenser to said lower-end of said coil. 1

12.*Apparatus for distilling oil, comprising a still, 'a return-condenser connected therewith, a-coil open at its upper end to the vapor space of the still', means for heating said still and said coil, the latter to a greater' temperature than the oil in the still, a con` duit for conveying oil from said still tothe lower end of'said coil, a check-valve in said conduit, a conduit for conveying the higherboiling portions from said return-condenser to said lower end of the coil, and a checkvalve in said conduit.

13. Apparatus for distilling oil, comprising a still, a return-condenser connected therewith and having independent draw-off pipes -connected thereto at various zones of condensation, a coil open at its upper end to the vapor-space of the still, means for heating said still and said coil, the latter to a greater temperature than the oil in the still, means for .conveying oil from the still to the lower end of said coil, and a manifold to which said draw-off pipes are connected, said manifold opening into said lower end of said coil. 14.. Apparatus for distilling oil, comprising a still, a furnace beneath said still, a coil beneath said still having its upper-end open to the vapor-space of the still, a returncondenser adapted to receive the vapors from said still and" having independent draw-olf pipes connected thereto at its various zones lyo and a manifold to which said draw-off pipes are connected, said manifold opening into' said lower end of said coil.

15. Apparatus for distilling oil, comprising a still, a furnace beneath said still, a coil beneath said still having its upper end open to the vapor-space of the still, a return-condenser adapted to receive the vapors from said still and having independent draw-off pipes connected thereto at its various zones of condensation, a conduit for conveying oil from said still to the lower end of said coil, a carbon-separator interposed in said conduit, and a manifold to which said draw-off pipes are connected, said manifold opening into said lower end of said coil.

16. Apparatus for distilling oil, comprising a still, a furnace beneath said still, a jacketed coil beneath the still having its upper end open to the vapor-space of the still and the jacket thereof being filled with molten material, a return-condenser adapted t0 receive the vapors from said still and hav ing independent draw-oli:` pipes connected thereto at its various zones of-condensation, means for conveying oil from the still to the lower end of said coil, and a manifold to which said draw-olf pipes are connected, said manifold opening into said lower end of said coil. j

17. Apparatus for distilling oil, comprising a still, a coil open at its upper end to the vapor space of the still, a return condenser adapted to receive the vapor from said still, means for heating said still and said coil, the

-injecting-means for the oil.

18. A pipe for use in distilling oils, coml` prising an inner pipe adapted to c onduct the iuid to be heated, and' an outer Jacket subform a chamber between the two, said chamber being filled with metal fusible at a relativelyA low temperature and means for allowing the` fusible metal to expand.

'stantially concentric with said inner pipe to 19. A heating coil for use in distilling oils,

comprising an inner pipe adapted to conduct the Huid to be heated, and an outer pipe coextensive therewith to define a chamber of annular cross-section, said chamber` being filled with a metal fusible at av relatively low temperature and means for allowing the fusible metal to expand.

20. A heating coil for use in distilling oils, comprising an inner pipe adapted to conduct the luid'to be heated, an outer pipe coextensive therewith to define a chamber of an'- nular cross-section, said chamber being filled with a metal fusible at a relatively low temperature and an expansion chamber to allow l the fusible metal to ex and'. 4

In testimony whereo I aiiix my signature.,-

LAYTON csrmRMAN'.

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