US2281906A

US2281906A - Adiabatic fractionating column

Info

Publication number: US2281906A
Application number: US382777A
Authority: US
Inventors: Gale L Adams
Original assignee: Socony Vacuum Oil Co Inc
Current assignee: ExxonMobil Oil Corp
Priority date: 1941-03-11
Filing date: 1941-03-11
Publication date: 1942-05-05
Anticipated expiration: 1959-05-05

Description

G. L. ADAMS ADIABATIC FRACTIONATI'NG COLUMN Filed March -11, 1941 `Maly 5, 1942.

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@ALE L. ADAMS Patented May 5, 1942 1 A 2,281,906` ADIAnA'rrc rrmc'rn)NATING4 COLUMN Gale L. Adams, San Marino,

Socony-Vacuum Oil Company,

New York, N. Y.,

Calif., assignor to Incorporated,

a corporation of New York Application March 11, 1941, Serial No. 382,227

9 Claims.

The object of the invention is to provide means for maintaining a temperature gradient along the exterior walls of a fractionating column equal to the existing gradient within the column.A

The operation of reiluxing fractionating columns is liable to considerable disturbance caused by variations in atmospheric conditions reflected in varying shell temperature. The exterior lagging or insulation commonly used reduces but does not entirely avoid this fluctuation. The means here described does completely avoid fluctuations in shell temperature and also provides for the control of this temperature at a desired level at any point from the base to the top of the column.

Referring to the single drawing, I0 is any fractionating column, illustrated as a bubble plate column provided with bubble caps down-- comers l2, a bottom drainv |3, a vapor inlet pipe i4, a vapor outlet pipe I5, and a reflux condenser lt. This structure is conventional and no 'novelty in it is claimed. Per contra, the invention is not limited to this or any particular type o fractionating column but is equally adapted to columns provided with perforated plates, grids. and packings of coke or Raschig rings.

Outside the shell of the tower I form a tight jacket il which provides a vapor space I8 substantially surrounding the shell. At more or less the. upper end of the jacket the vapor space communicates through a pipe I9 with a condenser 2|), which in turn delivers condensate to the lower end of the vapor space through pipe 2| which may have a control valve 22. The two condensers are supplied with cooling liquid such as water,

from a main 23 and branches 24 and 25, controlled by valves 26 and 21.

In the lower portion of the vapor space a heating element 28 is immersed in a pool 29 of a liquid which has a narrow boiling range approximating that of the light fraction to be taken `from the tower. This heating element is illustrated as a pipe coil supplied with a hot fluid through pipe 30 controlled by a valve 3|.

Thisvalve may y desirably be actuated by a diaphragm regulator 32 responsive to'the pressure within the jacket,

. but may be manually operated if preferred. The

coil may be supplied with steam for relatively low tower temperatures or with preheated heavy oils or solutions of salts for higher temperatures.

The showing of a heating coil is illustrative only and, particularly in apparatusof small size, may be substituted by an electrical resistance element, a suitable rheostat then Jreplacing valve 3|.

The liquid forming pool 29 may. as said, have a boiling range substantially equal to that of the top cut from the tower, or it may have a somewhat lower boiling point at equal pressure and be maintained in the jacket at such advance over tower pressure as to bring its vapors to the desired temperature. In operation this liquid is kept gently boiling so as to bathe the fractionator shell in vapor of the desired temperature, the vapor column passing upward through the jacket and being returned in liquid form by condenser 20. A desired temperature gradient within the jacket may be maintained by regulating valve 22, which controls the amount of liquid circulated andl consequently`of vapor passing through the jacket, while the pressure-responsive valve 3| controls the supply heat to prevent rise in pressure when valve 22 is partially closed and liquid backed up into the condenser. The entire apparatus may well be lagged as indicated at 33.

I claim as my invention:

1. Means for controlling the temperature of the shell of va fractlonating tower, comprising: a jacket forming a vapor space substantially surrounding said tower; a pool of substantially constant boiling liquid in the lower portion of said vapor space; heating means immersed in said pool, and condensing means communicating with both the upper and the lower portions of said vapor space.

2. A device substantially as and for the purpose set forth in claim 1, including valve means between said condenser and said vapor space.

3. A device substantially as and for the purpose set forth in claim l, including means responsive to pressure in said vapor space arranged to control the quantity. of heat supplied by said heating means.

4. Means for controlling the temperature of the shell of a fractionating tower, comprising: a .jacket forming a vapor space' substantially surrounding said tower; a pool of volatilizible ,liquid in the .lower portion of said vapor space; yheating means immersed in said pool, and condensing means communicating with both the upper and the lower portions of said vapor space. 5.Means' for controlling the temperature of the'glsvhell ofvav fractionating tower, comprising:

4 ja Jacket forming a vvapor space substantially surrounding said tower; means for supplying vapor to the lower end of said space; means for withdrawing vapor from the upper end of said space; means for controlling the temperature of the vapor supplied to said space; and means for vregulating the rate of said withdrawal of vapor.

` lating the rate of 6. The method of controlling the temperature of the shell of a fractionating tower which coming said tower, and controlling the temperature gradient within said closed space by regulating the rate of flow of said vapor.

7. The method of controlling the temperature ofthe shell of a fractionatlng tower which comprises: boiling a liquid in the lower end of a closed space i substantially surrounding said tower; removing vapor from the upper end of said closed space; and controlling the temperature gradient Within said closed space by regusaid removal of vapor.

8. The method of controlling the temperature of the shell of a fractionating tower which comprises: boiling a pool of liquid in the lower end of a closed space substantially surrounding said tower; removing vaporfrom the upper end of said closed space; regulating the quantity of heat supplied to said boiling pool to maintain a predetermined pressure thereupon; and controlling the temperature gradient within said closed space by regulating the rate of said removal of vapor.

9. The method of maintaining'adiabatic conditions within a tractionating tower which comprises: boiling, in the lower end of a closed space substantially surrounding said tower, a pool of liquid havingv substantially the same boiling range as that of the overhead fraction to be withdrawn from said tower; removing vapor from the upper end of said closed space; regulating the quantity, of heat supplied to said boiling pool to maintain the vapor temperature immediately over said perature within the adjacent portion of said fractionating tower; ,and regulating the rate of said removal of vapor to equalize the temperature gradient within said closed space to the tem- 20 perature gradient within said fractlonating tower.

GALE L. ADAMS pool equal to the vapor tem-y