Filed March 22, 1922 Sept. 7 1926.

EEE'EEE Patented Sept. 7, 1926.

UNITED sr'isrrlssv "PATENT OFFICE'.

'CARL 1I. PAGE, 0F GENEVA., ILLINOIS, ASSIGNOR TO GEORGE FABYAN, OF GENEVA,

ILLINOIS.

APAJRATUS FOR QRACKING OIL.

i Applicationyfllledlarclg 22, 1922. Serial No. 545,766.

It is an object of this invention to produce an auxiliary heati'ng device for use within a still.

It is a further object of this invention to provide for gradually heating the oil vapors from a temperature just below that o f cracking to the. cracking point and permitting the cracked vapors to coolagain to a temperature slightly below the cracking point.

It is a further object of this invention to control the flow of vapors past the heating device in such a way that a sudden expansion of the vapors shall occur just after the point of maximuxnheating is` passed.

It is a further object ofthis invention to provide an auxiliary heating device for an` oil stillvwith means leading from outside the still for supplying the heat.

Other and further important objects of this invention will be apparent from the disclosures in the specification and the accompanying drawings.

The invention (in a preferred form) is illustrated in the drawingsand hereinafter more fully described.

On the drawings:

Figure 1 is a view, partly in section, of a still with this invention applied thereto.

Fi re 2 is a vertical section through the auxiliary heating device.

Figure 3 is a section upon the line 3 3 of Fire 2. l

s shown on the drawings The still includes the usual boiler-sha ed receptacle 1 set over a furnace 2 which as the usual stackl. The still has the usual outlet pipe 4. In the top of the still are a number of domes or caps 5 which serve to support the auxiliary heating devices which constitute the subject of this invention. As illustrated, there are two such caps shown and two such auxiliary heaters use but an upon t e size of the still and the rapidity with which it is worked.

The caps 5 serve to support the auxiliary heaters inany desired fashion. As illustrated, the top'of each cap is a plate 6 which supports a sleeve 7 surrounding the stack 8 which leads away from the auxiliary heater. The stack is su ported from the sleeve in any desired fashion and the sleeve serves to hold the lower endof the stack in the proper position. Entering each stack at a The the cylinder 13 and pla s against the curved projection 24, the upper end number may be used, depending- -a pipe 9 for supplying air. Airis driven through. this pipe from any desired source of supply, such as a blower.- Anoil pipe .10 enters through the wall of the pipe 9 and continues inside the pipe 9 to the point 11 where the pipe 9 is joined-to at funnelshaped mouth 12 which is continued by a cylindrical chamber 13. The pipes 9 and 10 are controlled by suitable valves to regulate the flow of oil and air. The .stack 8 is continued by a Haring end 14 which joins the c lindrical wall 15 that constitutes the outsi e of the combustion chamber.

Oil'emerging from the end of the ipe 10 at the point 11 mingles with. air rom the pipe' 9 and is ignited 1n any desired way. ame emerges from the lower end of surface 16 of a body o refractory material, which closes the lower end of the combustion chamber. The material used should be a poor conductor of heat. Fire clay or some similar substance may be used. This body 17 is held in place by a plate 18 integral with the walls 15 and closing the lower end of the cylinder, A similar-'body of fire clay 19 fills the space between the cylindrical wall l5 andthe conical wall 14. This body is covered over by a top plate 2O which may also-be secured to the walls 15.

The funnel 12 and the cylinder 13 are'secured in position by bolts or rivets 21. The bolts 21 pass through spacing blocks 22 which serve to separate the cylinder 15 from the outer wall 23 of the auxiliary heater. The bolts 21 also serve to support this outer wall. The passage. between the cylindrical wall 15 and the wall 23 is constricted near the lower end of the wall 23 by an oblique of which is shown in thedrawing as coming opposite the lower end of the cylinder 13. The proper position of the, upper end of this obstruction depends upon the conditions met in any particular still. It should be located opposite the point at which the wall 15 is heated to the highest temperature. The upper end` of the obstruction 24 is an annular flange 25 so vthat the assage 30 between the walls 15 and 23 is iist gradually narrowed and then abruptly widened to its full width.

In the operation of this device, the oil in the still 1 is heated by the re in the furnace 2 until it reaches nearly the cracking point. The vapors arising from the `heated oil Ibefore this pointI is passed, pass o f through the outlet 4. As the cracking point is neared, the valves in the pipes 9 and 10 are opened andY the oil mingled with the air in the chamberf12-13 is lighted so that the space above the body 17 -is lled with flame.

The mixture of oil and air passes down the4 The result is that the Walls gradually increase in temperature from the point where the surface 16 meets the Walls, to a point a little higher above, and then slowly and gradually decrease in temperature to the beginning of the funnel 14. Part- .of lthe heat due to the burning will be reflected back into the combustion chamber and the funnel 14 thus protects the upper portion of the walls lfrom the full force of such heat. The fireclay 19 aifords additional protection to the upper part of the walls 15; consequently, from the point at the beginning of the funnel 14 to the upper end of the walls 15 the decrease in temperature is more rapid. Such heat as remains in the products of combustion when theyenter the stack 8 serves to partly vaporize the oilin the part of pipe 10 inside of the stack so that the iiame is readily maintained.

Oil vapors in the still l" are drawn into vthe passage 3@ between the walls 15 and 23 1 by convection, they pass up the narrowing passage between the obstruction 24 and the walls 15, and are heated as they pass, so that at the moment of their highest temperan ture they are at the narrowest part of the passage. ln the proper operation of the device, this is the cracking. temperature. The vapors debouch fromv the narrow part of this passage into the full sized passage and are thus enabled to expand abruptly. .This sudden expansion cornes while they are at the cracking temperature, with the result that it assists materially inproducing the cracking. The cracked vapors passing up the remainder oit the passage are cooled not suddenly but gradually, with the result that the reactions can go on -for a time ater the point of maximum temperature is passed. This assists materially in the production oit a compound closelyresembling sweet gasoline, and the unsaturated compounds have ample opportunity to become changed duringthe gradual cooling. rllhis action is materially assisted by ma ring thesurface of the Wall 15 of catalytic'rnaterial. lron is itself a good catalyst for this purpose, but for cernsaid walls whereby said tain oils the wall 15 may be of aluminum or may be covered with aluminum oxide t0 advto the point of condensation are finally delivered at the outlet4.

It should be remembered that although heating andcooling are spoken lof in describing the 'passage of the vapors between,

the walls 15 and 23, the total change in temperature during this passage is small h' l`his is because 4the vapors enter this passage at nearly the cracking temperature. The heating done during this passage is to a point only slightly, if any, above the cracking temp'erature, and the cooling is to a point corresponding to the temperature of the still as a whole, which is slightly below the cracking temperature. The whole difference of temperature between the lower and upper ends of the passage through the auxiliary heater should be only just suliicient to maintain a convection current therethrough. This need not be as great as would otherwise be necessary since the cracking itself I produces changes in the s eciic gravity of the vapors.

l am aware t at numerous detailsof construction may be varied through a wide range without departing from the principles 'of this invention, and I therefore do not purpose limiting the patent granted otherwise than necessitated by the prior art.

I claim as my invention:

,1. in a heatin -device for thevapor space ot' an oil still, two walls constituting a passage, an obstruction narrowing said passage relativel to other vparts of said passage, means or locally heating one of said walls whereby said assa e is at a higher temperature at a point a jacent said obstruction.y l

42. ln a heating device for the vapor space of an oil still, two walls constitutin a passage, an obstruction narrowing sai passage, means for locally heating one of assage is at a higher temperature at a olnt adjacent said obstruction, the area o. said passage diminishing from the entrance thereof to the point of greatest obstruction and then abruptly enlarging -to the full area of the passage.

3. In a heatin device for the vapor space of an oil stil, two walls constituting apassage, an obstruction narrowingV said passage, means for locally heating one of said walls whereby said. assafe is at a higher temperature at a pomt adjacent said obstruction, the area of said passage diminishing from the entrance thereof to the point of greatest obstruction and then abruptly enlarging to the full area of the passage, and the heated wall having a surface of catalytic material.

4. In an auxiliar heater for an oil still, a combustion cham er, an air pi' e leadin to said chamber, Aan oil pipe within sai air pipe and also leading to said chamber, a pipe for the products of combustion leading away from-said chamber, heat insulating means for conning the heat of combustion to a portion of the walls of said chamber, and a vapor conducting means surrounding said chamber.

5. In aheating device for the vapor Space of an oil still, an air ipe, an enlar ment at the end of sai pipe means r admitting combustible material into said enlargement, a chamber surrounding said enlargement, a jacket surrounding said chamber means extending through the walls of said chamber for supporting said enlargement, said means also sup orting said jacket. l 6. In a heating device or the vapor space of-an oil still, a cylindrical chamber, means within said chamber for heating the same, an external cylinder surrounding said cylindrical chamber, a conical obstruction on the interiorof said external cylinder, whereby an annular constricted opening exists in the passage between the said concentric cylinders.

CARL M. PAGE.