US1911836A - Method for flash distillation of oils - Google Patents

Description

May 30, 1933. N. E. LOOMIS METHOD FOR FLASH DISTILLATION OF OILS Filed Jan. 22, 1929 E mag l Patented May 30, 1933 UNITED STATES PATENT OFFICE iurmmm. 11. rooms, or wnsrrrann, aw mnsmr, assmnon. ro sranman on.

DEVELOPMENT company, a coaroaarron or nnnawaaa METHOD FOR FLASH DISTHJLATION F OILS Application filed January 22, 1989. Serial No. 884,153.

This invention relates to the art of heat treating hydrocarbon material, more= particularly to the distillation or cracking of mineral oils, and will be fully understood from the following description, read in conjunction with the accompanying drawing, in

Y which I i Fig. 1 is a vertical section of a preferred form of apparatus for carnying out my inp evaporator 15. The drum 15 may be anordinary shell stillprovid'ed at each end with V removable manheads 16 and vapor draw off line 17. A slightly lower ressure, not substantially above atmospheric andpreferably a partial-vacuum is maintained in the drum 15 whereby the hydrocarbon materiahheated to its va orization point in the coil, tends to immedlately flash into vapor form as it is discharged from the nozzle 14. Vapors pass off from the drum 15 thru a vaporline 17 to a condenser 18 whence the condensate passes by pipe 20 providedwith a valve 19 to a receiver 21 provided with a condensate draw-off connection 210. and a. valved pipe 21?) leading to a source of suction.

In flashing heavy residuum to coke, difliculty is experienced in securing a product sufliciently free of oil to be cleaned readily 40 from the evaporator or to be pulverized for powdered fuel. This is due to the difliculty of maintaining-a sufliciently high temperature in the evaporator to completely vaporize all of the volatile matter. Some heat may applied externally to the evaporator, but this is generall undesirable because it makes the coke har to remove.

In In improved method, I correct the heat de ciency by introducing a relativel small amount of air into the evaporator 13;

whereby a partial combustion of. the hydrocarbon material is eifected and the temperature in the evaporator is increased suflicient' 5y to produce a substantially oil-free coke eposlt.

n the referred construction of my apparatus, I have shown the air introduced thru pipe 22 which discharges into the atomizing nozzle 14 preferably at a point such that little or no contact between the hydrocarbon material and the air is effected in the nozzle itself. I may, however, introduce the air near the bottom of'the evaporator 15 by means of a perforated pipe or thru a false bottom provided with suitable perforations. Other modifications may suggest themselves for this purpose and I contemplate any means of securing intimate con-, tact between an oxygen containing gas and the heated hydrocarbon material in a flash chamber as coming within the scope of myinvention.

My invention is particularly applicable to. the treatment'of tar residue from cracking operations. Referring to Fig. 2, I have shown my invention as used in conjunction with a cracking apparatus of the tube and tank type.

Stock to be cracked, for instance, gas oil, is pumped by pump 2 from a source of supply A to a cracking coil 1, from which the eated products are discharged by a pipe 3 into the soaking drum or dlgester 4 where, due to the greatl reduced velocity of flow thru the drum, t e greater portion of the cracking occurs. The cracked roducts are withdrawn from the soaking rum 4 by a pipe 5 preferably provided with a valve 5a,

and discharged into a separating chamber '6. A lower. pressure may be maintained in the separator 6 than is maintained in the soaking drum 4, whereby light fractions are vaporized and drawn off thru vapor line'7 to a suitable condenser 8, the condensate passing thru line 9 provided with valve 90 a to a receiving drum 10.

Unvaporized products separated in the chamber 6 are withdrawn thru a line 11 providedwith a: throttle valve 13a and gassed thru heating coil 12 whence they are ischarged by pipe 13 terminating in a nozzle 14, into an evaporator 15. Light fractions are vaporized in the evaporator 15, which is maintained under a slightly lower pressure not substantially greater than atmospheric and preferably a partial vacuum, and are withdrawn thru vapor line 17 to a suitable condenser 18. Condensate passes from the condenser 18 thru pipe 20 provided with a valve 19 toa receiving drum 21.

The evaporator 15 is provided with removable manheads 16 to render the drum accessible for cleaning out. Air is-supplied to the nozzle 14 thru a line 22, as described above, or. by any other means so as to insure intimate contact with the hot liquid entering the drum, whereby sufiicient heat is generated to completely vaporize all the volatile products and leave a dry coke residue.

I may, if desired, provide a lining of refractor material in the flash chamber, altho this is not usually necessary if the amount of air admitted be carefully regulated.

It will be understood that a pump, not shown, may be interposed between the separator 6 and the heating coil 12 in case the ressure'in the separator is not sufiicient to orce the tarry residue thru the coil.

The following example is illustrative of my invention.

Tar residue from a crackin rocess having a viscosity of about sec. Furol at 210. F., and boiling at substantially above 500 F., is drawn from a storage tank, or preferably without cooling from the vapor separator -6 of a cracking 21133311113113, as shown in Fig. 2, and is passe thru a heating coil 12 in which it is heated to 7 50800 F.

i In this heating stage I may maintain con- 'siderable pressure upon the material being treated, say 150'pounds per square inch or more, but preferably I maintain only such pressure as is necessary to force the material ,thru the coil andv deliver the heated material to the evaporator. The evaporator is maintained. at atmospheric or slightly .reduced pressure. The heated material is discharged in atomized form into the vapor s ace of the evaporator thru an injector nozz e of which different types are well known, together with a small amount of air. I prefer toint-roduce the air at or near the int 'at which the heated material is introduced, but if this method is used, care must be taken to insure that combustion does not occur within the injector nozzle itself as the tem eratures produced may result in injury or estruction of the nozzle.

The 'gamount of air introduced is carefull regulated to maintain a temperature in t e evaporator of approximately 850 F. At this temperature all vaporizable constituents are volatilized and. withdrawn in the form of vapors. 'The coke-forming bodies in the tar are precipitated as a hard, dry coky residue which may be easily removed at suitable intervals and which is well adapted to be pulverized for use as powdered fuel, in the manufacture of briquettes, or for other purposes.

It will be understood that while I have described only two forms in which my invention may be used, other forms and modifications are contemplated which come within the spirit and scope of the invention.

I claim: I 1. The method of distilling heavy hydrocarbon material containing coke forming bodies, which comprises passing the material in a restrictedstream through afheating zone, reducing the pressure, atomizing the material into a vaporizing zone, injectin suflicient oxidizing gas into the atomize material in concurrent flow therewith, to efifect the partial combustion necessary for volatilization of substantially all volatile components, and withdrawing the vaporized products, whereby substantially oil-free coke residue is obtained in the said vaporizing zone.

2. The method of distilling heavy hydrocarbon-material containing coke forming bodies, which comprises passing the mate rial in a restricted stream through a heating zone, reducing the pressure, atomizing the material into a vaporizing zone, injecting air into the atomized material in concurrent flow therewith, to efiect the artial combustion necessary for volatilization of substantially all volatile components and withdrawing the vaporized products, where-- by substantially oil-free cokeresidue is obtained in the said vaporizing zone. v

3. The process of recovering oil-free coke from heav cracking o a hydrocarbon oil, which comprises passing the residuum in a restricted stream through a heating zone, reducing the pressure, atomizing the residuum into a vaporizing zone, in ecting sufiicient air into the atomized residuum in concurrent flow therewith, to effect the partial combustion necessary for volatilization of substantially all volatile components, and withdrawing the vaporized products, whereb substantially oil-free coke residue is o tained in the said vaporizing zone.

NATHANIEL E. LOOMIS.

residuum resulting from the I

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