US1355311A - Apparatus for treating hydrocarbons - Google Patents

Description

J. W. COAST, JR.

APPARATUS FOH'TREATING HYDROCARBONS. APPLICATION'i Ful-ED MAY 5.1917.

1,355,31 1 Patented Oct. 12, 1920.

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TOHN W. COAST, JR., OF TULSA, OKLAHOMA, ASSIGNOR T0 THE PROCESS COMPANY, CORPORATION 0F MARYLAND.

APPARATUS FOR TREATING HYDROCARBONS.

Specication of Letters Patent.

Patented Oct. 12, 1920.

Application led May 5, 1917. Serial No. 166,525.

the following is a full, clear, and vexact de-` scription, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to improvements 1n apparatus for treating hydrocarbons, and more particularly to means for cooling hydrocarbon vapor and at the same time heating a body of liquid. The new apparatus may be used in cracking petroleum hydrocarbons under pressure, to obtain a product known as gasolene, or cracked gasolene. In cracking such hydrocarbons, the vaporized fractions having relatively high boiling points shouldbe condensed and returned to the still for' further treatment, and' the fresh charge of oil should be heated before it reaches the still. One of theobjects of my invention is to provide a simple and efficient means for accomplishing these results.

In the preferred form of the invention, a body of relatively cool liquid is maintained in a heat exchanger, and the hot vapor passing from the. still is discharged into this liquid. The hot vapor is permitted to rise in the forni of bubbles in the relatively cool liquid, thereby heating the liquid and at the same time condensing the previously vaporized fractions having relatively high boiling points. The body of liquid maintained in the heat' exchanger may be formed partly by the high boiling point condensate, and partly by a fresh charge of oil. In this event, the hot condensate will serve as a heating medium for the fresh charge of oil, and the liquid mixture will be constantly subjected to the heat of the vapor which bubbles through the liquid. Some' of the liquid will be converted into vapor and pass to a condenser.v The heated liquid preferably overflows and passes to the still. Some of this overflowing liquid is condensate formed by condensing the high boiling point fractions, and some of it is preferably a fresh charge of oil which has been subjected to the heat of the vapor and condensate.

The drawing is a diagrammatical view of an apparatus embodying the features of my lnvention.

To illustrate the invention, I have shown a crackmg apparatus comprising a pressure still 1 arranged above a heating chamber 2, a vapor pipe 3 leading from the still to a heat exchanger A, a vapor pipe 4 connecting the heat exchanger to an air cooled reflux condenser 5, and a vapor pipe 6 con-v necting said reflux condenser to a water cooled condenser 7, from which the product 1s recovered. A pressure, regulating valve 8, in the vapor pipe 6, may be regulated to maintain a predetermined pressure 1n the refiux condenser, heat exchanger A, and also in the still 1. A perforated discharge member 9, connected to the vapor pipe 3, is submerged in a relatively cool body of hydrocarbon liquid containedin a reservoir 10. These members 9 and 10 form part of the heat exchanger A, and they are so arranged that the cool liquid will form a liquid-seal in the vapor line. An overflow pipe 11, provided with a liquidseal, or trap, 12, leads from the surface of the liquid in the reservoir 10 to the lower portion of the still 1. A pump 13 may be used to force a fresh charge of relatively cool hydrocarbon oil through a pipe 14 and into the reservoir 10 The new apparatus may be used in cracking various heavy hydrocarbon products resulting from the treatment of crude petroleum, particularly such inexpensive hydrocarbons having boiling points higher than 350 F., the most beneficial results being obtained from hydrocarbons having boiling points ranging from 450 F. to 700 F. The valve 8 in the vapor pipe 6is adjusted to obtain the desired pressure in the still, heat exchanger A and reflux condenser 5. The pressure may range from 50 to 150 pounds per square inch, or even higher, but it is preferably maintained atabout 85 pounds per square inch. The contents of the still are preferably subjected to such a high degree of heat that the hydrocarbon liquid will vaporize very rapidly. This tempera'- ture may range from about 600 F. to 800 F., and is preferably about 725 F.

Owing to the intense heat and the rapid vaporization, a large volumel of unconverted, or partially converted, hydrocarbons will flow from the stillv 1 to the heat exchanger Jcondensing the previously vaporized fractions having relatively high boiling points. By bubbling the vapor through a relatively cool liquid, as herein shown, all of the vapor is very effectively subjected to the action of the cool liquid, and the heaviest fractions are condensed and preventedfrom passing to the main condenser. The heat exchanger thereforeY constitutes a highly efficient condenser for the high boiling point fractions.

The hottest portion of the liquid overflows from the heat exchanger a-nd passes through the overflow pipe llto the still l. This overfiowing liquid flows by gravity to the still, the heat exchanger being higher than the still. To prevent the vapor from fiowing through the overflow pipe 11, the discharge end of said pipe is preferably located near the bottom ofthe'still. It will be observed that the body of liquid above the discharge end of pipe 11, is vdeeper than the body of liquid above the vapor discharging member 9.

Thefresh charge of relatively cool oil, fiowing from the pipe 14, commingles with the hot condensate in the heat exchanger A, and is also subjected to the high temperature of the hot vapors bubbling through the` liquidvmixture in the heat exchanger. The fresh charge of oil is thus subjected to a very high temperature, and thoroughly heated, before it overflows at the surface of the liquid body in the heat exchanger.

The reflux condensate,fflowing from the condenser 5, passes through the pipe 4 and commingles with the liquid in the heat exchanger, this condensate being heated before it overfiows to the still.

The desirable low boiling point fractions flow from the reiiuxcondenser \5, through the vapor pipe 6, andl into the main condenser 7, where they are condensed to form the low boiling point product.

It will now be understood that the hot vapor, bubbling through the hydrocarbon liquid in the heat exchanger, is cooled so as to separate the high boiling oint fractions from the lighter ractions; t e hot condensate returns freely to the still; the fresh charge' of oil is thoroughly'heated by the vapor and also by the hot condensate; the

heat exchanger also serves as means for heating the refiux condensate fiowing from the condenser 5, and although the vapor is bubbled through the liquid, it will be apparent that the heat exchanger will perform its several functions while maintained under the high pressure necessary to crack petroleum hydrocarbons.

The method herein disclosed is claimed in an application for pttent filed by me on May 5, 1917, Serial o. 166,524.

I claim:-

1. In an apparatus for treating hydrocar- A bons, a still, a heat exchanger comprising a reservoir wherein a body of hydrocarbon Y a reflux condenser arranged to receive the p vapor bubbling from the surface of said liquid, said reflux condenser bemg positioned to return its condensate to said reservoir,

a main condenser communicating with the reflux condenser, said reservoir being higher than the still, and an overflow conductor whereby heated refiux condensate is permitted to flow, by gravity, from the top of the liquid in said reservoir to the still.

2. In an apparatus for treating hydroi carbons, a still, a heat exchanger compris- Aing a reservoir wherein a body of 'hydrocarbon liquid is maintained and 'a vapor conductor whereby vapor passing from the still is discharged into said body of hydrocarbon liquid, said vapor conductor having a perforated discharge member submerged in said liquid to provide for the discharge of numerous small streams of hot vapor into the liquid, a reflux condenser arranged to receive the vapor bubbling from the surface of said liquid, said reflux condenser being positioned to return its condensate to said reservoir, a main condenser communicating

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