US 1476744 A
Description (OCR text may contain errors)
A. A. 3. n@ 7 Aw 11 S Y E K T A W L TU 2 9 11 COOLING STILL Filed Nov. 22 1921 35u LX y 977 Patented Dec, l, 1923.
THOMAS WATKEYS, 0F PORT ARTHUR, TEXAS, ASSIGNOR TO GULF REFINING COM- PANY, OF PITTSBURGH, PENNSYLVANIA, A. CORPORATION OF TEXAS. 4
COOLING STILL Application led November 22, 1921. Serial No. 517,022.'
To all whom t may cmwem:
Be it known that I, THOMAS L. WATKEYB, a citizen of the United States, residing at Port Arthur, inthe county of Jefferson and State of Texas, have invented certain new and useful Improvements in Cooling Stills, of which the following is a specification.
This invention relates to cooling stills; and it comprises a method of lcooling stills which have been used for the production of gasoline and the like from higher boiling oils with the aid of aluminum chlorid and which contain exhausted aluminum chlorid residues, wherein hot residual oil in the still is displaced by cooler oil and the still is Hooded with cold high boiling oil-'until it is cold or nearly so; all as more fully hereinafter set forth and as claimed.
In the manufacture of gasoline and other low boiling oils from higher boiling oils, one of the processes now in useis to heat the hi h boiling oil with anhydrous aluminum chIorid. In so doing, the high boiling oil, gas oil, for example, enters into ebul ition at a temperature below. its normal boiling point, giving vapors of lower boiling oils, such as gasoline. By the use of proper methods, large yields of gasoline can be made in-this way from various high boiling oils. After a time, the aluminum chlorid loses its activity and becomes converted into a tarry or coky mass. By the use ofvarious expedients, itis possible to remove this residue from the still in greater part, and continue the opera-tion with the addition of fresh aluminum chlorid; but after a time, it is necessary to stop the distillation and cool down the still for cleaning. Sometimes theoperation is intermittent and the still is cooled down after the use of a single charge of chlorid. As these Aoperations are ordinarily carried out in large apparatus units, the cooling down offers considerable difficulty. The expedient in use with coking s'tills and the like of blowing in steam for cooling is not here practical, for the reason that steam instantly produces hydrochloric acid from these resldues. And with a 1000 barrel still, bricked up in the usual way and heat insulated, natural cooling after dlscontinuance of firing may take a weeks time.
It is the object of the present invention to provide a simple and economical way of quickly cooling stills of this ty in the use of aluminum chlorid, distillation As stated, I
is continued until the aluminum chlorid residues have substantially no further converting activity upon oil. Such being the case, it is practicable in cooling one of these stills to produce a flow 'of cold oil through it until the Whole apparatus is cooled to the desired temperature. In practice I first draw ofl' the aluminum chlorid sludge or coky residue and then displace the hot oil in the still with cool oil, so that the temperature ofthe hot oil in the still is gradually lowered, and I remove the oil from the still which is being cooled and sendit advantageously through cooling coils and thence back to the still or to the stock tank. I may deliver cool oil toward the bottom of the still v to be cooled and send the removed oil from vantageously such as is used in the distilla-4 tion of higher boiling hydrocarbons with anhydrous aluminum chlorid for the production of lower boiling hydrocarbons. stills are usually provided with stirring mechanism, the shaft of which is shown at 2, driven vby gear 3., in turn driven b pinion or worm on sha-ft 4, supported by brackets 5, and driven by pulley wheel 6. The chargle of oil, or oil and aluminum chlorid, is a mitted at 7 and residual oil and aluminum chlorid sludge or residue may be removed through pipe 8. The still -is equipped with vapor line 9 leading to the coolers. The still may be fired by fire box 10. This construc-v tion forms no part of my invention.
After operating` the aluminum chlorid process for some time, it is necessary to clean out the stills, or it may be necessary to repair them. Before this can,be done, the stills must be reduced to a temperature sufliciently low to permit entrance of workmen. Assumin that there has been an valuminum chlorid distillation performed in the still, the heavy aluminum chlorid sludge 0r coky residue may be withdrawn through pipe 8. There will then remain in the still.
a considerable portion of hot unconverted Suchv l higher boiling oil. Higher boiling oil from f the oil stock tank 11 may then be sent to the still by means of the pump. 12 by means of the Valved line 13 entering at `a low point in the still and the hot oil in the still is displaced, owing out near the top of the still through valved line 14, either to the cooler 15 through valved line 16 or back to the stock tank through valved line 17. lf the oil is sent to the cooler 15, it may be cooled therein by `means of water or the like flowing in at 18 and out at 19, and may then be sent. to the pump l2 by means of the valved line 201 Or the oil may be sent from the cooler directl to the stock tank 11 b means of Jthe va ved line 21. Or the 011 displaced from the still 1 through the line 14 may be sent directly to the stock tank 11 by means of line 17, more cold oil from the bottom ofthe tank being sent to the still through theiline 13. l
With the arrangement described it is therefore possible to displace the hot oilin the still by cold oil from the stock tank, or
cold oil from thel cooling coil, and to gradually lower the temperature in the still.
With my process l have been able to lowerthe temperature in the still within 12 hours to a point permitting entrance of workmen; whereas, when the still is allowed to cool in the usual way, a coolin period of a week or more is necessary. articularly in the aluminum chlorid stills, it is not lpossible to cool by means of steam, because the aluminum chlorid used in these stills must ge anhydrous and the stills mustbe kept lll mayl constantly feed in some fresh cold oil from the stock tank while leadin in cold oil from the cooling coils. And if esired l may reverse the How, su plying cold oil at the top of the still and withdrawing the hot oil from below.
What l claim is 1. The process of cooling hot stills used in treating oils with a catalytic agent which is rendered ineHicient by contact with water which comprises discontinuing the distillation and displacing the hot residual oil in a still with cooler oil.
2. rEhe process of cooling hotl stills used in treating oils .with a catalytic agent which is rendered ineiiicient by contact with water which comprises discontinuing the distillation anddisplacing the hot residual oil in a still with cooler oil, coolin the displaced oil which has become heate and usin it for cooling the still and displacing the rst used oil.
3. The process of cooling hot stills used 1n treating oils with a catalytic agent which is rendered ineiiicient by contact with water containing hot residual oil which .comprises discontinuing the distillation, adding cooler oil to the still, withdrawing the mixture and sending it back to the still.
. 4. The process of `cooling hot stills used 1n treating oils with a catalytic agent which is rendered inelicient by contact with water containing hot residual oil which comprises discontinuin the distillation, adding cooler oil to the sti l, withdrawing the mixtul-i, cooling it and sending it back to the s 1 y 5. The process of cooling stillsv used in treating o1ls with a catalytic agent which is rendered ineilicient by contact with water containing residual hot oil which comprises discontinuing the distillation, displacing the hot oil in the still by meansofcooler oil, cooling the hot oil in cooling apparatus and returning it to the still.
6. The process of cooling stills used in treating oils with a catalytic agent which is rendered inelicient by contact with water which comprises discontinuing the distillation and displacing hot oil therein by 4constantly circulating cooler oil.
ln testimony whereof, l have hereunto aiixed my signature.
THMAS L. WATKEYS.