US2112360A - Apparatus for cracking petroleum oil - Google Patents

Description

Match 29, 1938. c. P. DuBBs 2,112,360

APPARATUIS FOR CRACKING PETROLEUM OIL Original Filed July 5l, 1922 wiki "N v l Cear o?? P @H 65 rammed Mar'. 29, 193s 2,112,360

UNITED STATES PATENT. OFFICE carbon r. Dobbs, Newsiead, met, Bermuda, as- Y signor to Universal Oil Products Company,

Chicago, lll., a corporation of Delaware Original application July 31, 1922, Serial No. 578,705. Divided and this application May 21, 1936, Serial No. 81,085

3 Claims. (Cl. 196-107) This application is a division of my co-pending jected to the refluxlng action of the raw oil or application Serial No. 578,705, filed July 31, v1922. returned condensate which is introduced to the This invention relates more particularly to dephlegmator through the manifolds 8, 9 and I0 apparatus for the conversion of higher boilingA petroleum oil into lower boiling point products. Among the salient objects of the invention are to provide apparatus in which the oil vapors generated in an expansion or vaporizing chamber are relieved of their higher boiling point fraczone there is separated from the oil vapors the higher boiling point` fractions undesirable to the production of a low boiling point distillate.

At the bottom of the dephlegmator leg in addition to the draw-off line IB is a second draw- 10 tions in a dephlegmating zone so constructed to offline 21 which is controlled by valve 28 through reduce the superheat of the vapors and-separate which a portion of the condensates separated o ut out the higher boiling point products, and furin the dephlegmator together with quantities of ther controlling the temperatures of dephlegmaraw oil which it may contain, may be drawn tion so that a more uniform andbetter quality from the dephlegmator. This oil directed l5 distillate passes over to the nnal condensing through the line 21 may be passed through a cooler 29, thence through a line 30 regulated by a 4valve 3l to a charging pump 32 from which it is pumped through the line 33 to any one or all of the manifolds 8, 9 and I0 which are connected to the line 33 by secondary connections 34, 35 and 36. The amount of condensate returned in this manner to the separate manifolds may be regulated by the, valves 31, 38 and 39 interposed in the secondary connections. Thus, it is obvius that in addition to the introduction of raw oil to the manifold, the condensate may be also returned and introduced` in regulated quantities with the raw oil so that an accurate l control may be had over the temperature conditions maintained in the dephlegmating column at all times.

The vapors which remain uncondensed in the dephlegmator pass over through the line 40 in which is interposed a valve 4|, to the water condenser coil 42 mounted in the condenser box 43. The discharge end of the -condenser coil is connected by a line 44, regulated by a valve 45, to a distillate receiving tank 46.A The tank. is equipped with pressure relief-valve 41, pressure stage.

In the drawing, the single figure is a diagrammatic side elevational view of the apparatus.

Referring vin detail to the drawing, the oil to be treated is introduced through the line I which has separate connections 2, 3 land 4, controlled by valves 5, 6 and 1', respectively, to manifolds l, 9 and I0. The manifolds 9 and I0 are connected to circular roses or sprays I I and I2, while the discharge end of the manifold 8 extends through the T connection I3 and into the vapor line I4 in the form of a perforated pipe I5.

In introducing the oil to the system, it may be charged into the manifold Ill near the `top of the dephlegmator I 6 or into the manifold 9 which is positioned intermediate of the top and bottom of the reiiuxing column, or it may be charged through the lower manifold and into the vapor line through the perforated pipe I5 where it is charged near the bottom of the dephlegmator directly into the vapor line. l

The oil combined with what condensate it may separate from the vapors in -the dephlegmating stage,'wil1 collect in the dephlegmatorjleg I1 from which it is drawn oif through the line I8, controlled by the valve I9', and directed to the heating coils 25 mounted in the furnace 2|. A connecting pipe Y nishes a means for supplying additional raw oil to the charging line, if desired. After passing through the continuous coil 2li in the furnace, the temperature of the oil has been raised to a cracking heat, and in this condition it is introduced in a fluid state to the vaporiaing chamber 24. In this enlarged chamber the oil is permitted to collect, the vapors evolved .passing oi! through -the vapor line I4 and the liquid unvaporized products being drawn of! through the-line 25 which is regulated by the valve 25. The vapors passing through the dephlegmator Il are sub- 22, controlled by valve 23, fur` gauge 45.' liquid level gauge 49. A liquid drawoif line 50 connected tothe bottom of the tank is controlled by a valve 5I, and is connected to as explained. In the dephlegmating or refiuxing the suction side of a pump 52 by means of which the distillate may be charged back through the line 53 to any of the manifolds 8, 9 or IIl through the separate connections 54, 55 and 56, which are controlled by suitable valves. A line iii' is connected to the draw-off line liqand is controlled by the valve 58 whereby the distillate from 'the receiving tank may be withdrawn from the system instead of recycling it through the dephlegmating stage.

When thevapors from the expansion chamber are discharged into the bottom of the dephlcg mator without preliminary coo, the excess parts of the refluxing stag heat contained therein seriously interferes with the dephlegmating or proper reiluxing of the vapors so that the dephlegmator cannot eiilciently separate or sift out the higher boiling point fractions. Thus, owing to the superheat or excess heat of the vapors from the reacting or vaporizing chamber, a greater part of the dephlegmator is used for extracting this excess heat before a substantial amount of reiux condensation can take place. For this reason, the superheat of the incoming vapors must .be reduced, and this absorption of heat by the reiuxing column exhausts to a great extent the cooling capacity of the dephlegmator, thereby reducing to that extent the yeffectiveness of the apparatus in separating out the higher boiling point vapors. By cooling the vapors suflciently before orv just after they enter the dephlegmator a much more satisfactory separation of the higher boiling point fractions may be obtained,

lit has been found that by controlling the capacity of the dephlegmating stage through the introduction of cool oil in different parts of the dephlegmator a more satisfactory separation is obtained than when an apparatus, dependent upona radiating surface expo'sedto air, for controlling the capacity of the dephlegmating stage,

is used. e

It will be noted that by the pipe arrangement shown, it is' possible to cool or extract the superheat from the vapors in the vapor line prior to their entering the dephlegmator or into the lower part of the dephlegmator. In doing t his the cool oil is introduced through the perforated pipe I5. this oil consisting of the raw oil or combined feed or raw oil, returned condensate, or a combination of the raw oil, reux condensate and pressure distillate from the receiving tank.

Further dephlegmation is obtained by introducing regulated combinations of the oils mentioned to diiferent heights in the dephlegmator.

' It is understood, oi course, that oils differ in respect to their treatment, and the control oi' the dephlegmation will likewise necessarily be altered with the different types 0f oil "treated By proportioning the amount of cooling in the different l a more satisfactory and complete control for sifting of the vapors can be obtained, and allows the capacity of a given size dephlegmator to be substantially varied, for example-assume that the vapors in the vapor line have a temperature of from 800 to 820 F.,

these vapors may be cooled by the introduction l ofa cooling oil near the bottom of the dephlegmator to temperatures ranging from 600 to 700 F., which will condense a large part of the vapors having high boiling point fractions, while the remaining vapors having high boiling point cuts are condensed and thus separated out in the 1. An oil cracking apparatus comprising a heating coil and anenlargedchamber communicating therewith. a fractionator and means for passing vapors fromrthe chamber to the fractionator, a condenser -and receiver communicating with the fractionator, means for removing reilux condensate from the fractiona'tor, and means f for introducing charging oil, condensate from said receiver, and portions of said reflux condensate into contact with said vapors prior to their introduction to the fractionator.

2. An oil cracking apparatus comprising a eating coil and an enlarged chamber communieating therewith. a fractionator and means for passing vapors from thev chamber to the fractionator, a condenser communicating with the fractiona'tor, means for contacting condensate formed in said condenser with said vapors prior to their introduction to the fractionator, and means for returning reflux condensate from the iractionator to said coil.

3. An oil cracking apparatus comprising a heating coil and an enlarged chamber communieating therewith, a fractionator and means forpassing vapors from the chamber to the fractionator, a condenser communicating with the fractionator, means for contacting condensate formed in said condenser with said vapors prior to their introduction to the fractionator, means for introducing additional condensate formed in,r

said condenser into the'fractionator, and means for returning reux condensate from the fractionator to said coil.

' CARBON P. DUBBS.

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