US2196767A - Pyrolysis apparatus - Google Patents

Description

R. HASCHE PYROLYSIS APPARATUS Filed July 10, 1937- April 9,

s Sheets-Sheet 1 SE m Wm mm fi N W S Q Q 7 Rudolph LeonardHasche I INVENTQR.

April 9, 1940. RQL. HASCHE 2,196,767

" PYROLYSIS APPARATUS .Filed Jill 10, 1937 3 She ets-Sheet 3 A; TO 5 7746/1 I36 Rudolph Leandra Hasche INVENTOR.

I A ORNEYS Patented Ap 1940 UNITED S-TATES;..;PATENT OFFICE 2,190,167 rrnonrsrs arramrus Rudolph Leonard Hasche, Kingflport, 'lenn., as-

signor to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey Application July 10, 1937, Serial No. 153,045

11 Claims. (01. 23-277) cracking industry various apparatus has been constructed for pyrolysis of oils to various other materials. However, it will be noted that such q ipment in most instances is constructed entirely of metal thereby evidencing that the temperature of operation is low when compared with the temperatures with which my novel apparatus is adapted to withstand. In such prior art processes the temperatures have in many instances not exceeded 700 0., whereas my novel apparatus is suitable for operation at temperatures above twice this magnitude.

While some prior art apparatus has been constructed of refractory materials to withstand high temperatures, such apparatus has in many instances only been constructed on a small scale more or less suitable for laboratory uses. In other instances where refractory construction has been employed, since construction was not gastight, it would be unsuitable for the hydrocarbon materials because of various hazards, as well as the possibility of losses and contaminations due to leakages.

I have found that an apparatus may be con-- structed in accordance with the several novel features set forth herein which apparatus is capable of satisfactorily withstanding excessively high temperatures. My apparatus produces particularly satisfactory heating and conversion of the materials treated therein.

This invention has for one object to provide apparatus capable of use at high temperatures. Still another object is to provide pyrolysis apparatus satisfactory forthe high temperature. conversion of saturated hydrocarbons to unsatu-'v A still further object is to covering products produced therein. A still furtherobject is to provide pyrolysis apparatus having in combination thereinmeans for cooling, re-

cycling or otherwise treating products or byproducts produced therein. A still further object is to provide apparatus for use in high temperature pyrolysis processes, that is particularly adapted to continuous operation. Other objects will appear hereinafter.

For a more complete understanding of my invention, reference is madeto the accompanying drawings.

Fig. 1 is a diagrammatic side elevation view showing one form of general arrangement of high temperature apparatus in accordance with my invention.

Fig. '2 is a semi-diagrammatic side elevation I view on a larger scale, with certain parts broken away and in section for clarity, showing in more detail one of the high temperature units of my apparatus.

Figs. 4 and 6 are additional views of a type similar to Fig. 2, showing in further detail certain parts which may be employedin the construction of my apparatus.

Figs. 3 and 5 are end views of the parts shown in Figs. 4 and 6.

. Fig. '7 is a semi-diagrammatic side elevation view 'of a type similar to Fig. 2 showing an enlarged furnace unit which might be employed in my apparatus.

- Fig. 8 is a semi-diagrammatic side elevation view of the type shown in Fig. l of a modified horizontal apparatus arrangement in accordance with my invention.

Fig. 9 is a detailed view showing manner of fastening tubes.

' In high temperature apparatus the parts which are subjected to high temperatures for heating num silicate, zirconium silicate, fire clay, alumina and various fused. compositions, Such materials are more or less inflexible and if rigidly Joined to metal or cemented into other refractories, subsequent heating and the distortion produced thereby, produce the breaking of joints, the forming of cracks or other openings in various parts of the apparatus. In my apparatus I have found a construction whereby such defects may be avoided and at the same time refractory materials employed in the construction of my apparatus which will resist high-heating.

may be comprised. of various refractories and ceramic materials such as silicon carbide, alumi- "For a more complete understanding of my inin apparatus set-up, reference is made to Fig. 1.

In Fig. 1, the stock to be pyrolyzed may be supplied from the container I. Any force required for putting it in flow may be available from the natural pressure of stock in the container I, or from superposed gaseous pressure above the liquid therein, or by any other suitable means (not shown), such as by introducing a pump into the line 2. In the line 2 may be a valve 3 for regulating the rate of flow. Following valve 3 may be a fiow meter 4, followed in turn by a heater 1. The said heater is preferably put in use if the stock tends to condense, solidify or otherwise exert resistance to flow. The heater 1 may operate in the conventional manner by admitting a heating medium around the tube 6. At the pipe juncture II the stock may join with another material such as diluent furnished under pressure through the pipe l2 if it is desired to add such material. Valve l3 serves for adjusting the rate of flow of this other material, and I4 is a flow meter in the line. A pipe 60 may also make communication with the point of juncture II for admitting further material in a manner to be described hereinafter.

The various materials to be pyrolyzed thereby become intimately mixed in the pipe l5 which may carry the feed to a preheater 16. This preheater comprises a housing ,38 and a heating coil l1 that receives the feed from pipe IS. The heating medium for the feed in coil l1 may be flue gas in countercurrent, coming from the furnace 42 operating in conjunction. Flue gases forming in the combustion chamber 53 of the said furnace, pass into a duct 65, and may be divided into two streams by manipulation of the two dampers 3| and 40, which construction therefore serves as means for controlling the degree of preheat for the feed in coil l1. From the coil l1 the feed passes into the pipe-l9, in which there may be a chamber as at 65. If a chamber is not desired, the pipe l9 may lead directly to the trap 20. The purpose of this trap is to catch residues such as oils, resins, tars and the like that may form from thefeed at times due to the action of the preheater I6. Any accumulation in trap 20 may be drained at will through valve 2|.

Material that is not removed in the trap 20, continues through pipe 22, and enters the main pyrolysis tube 24 through a fitting 23. The tube 24 is heated by one or more burners as at 25, supplied with fuel and air, respectively, through valves 26 and 21 for regulating the degree of temperature in the said pyrolysis tube. Prefer ably there are at least two such burners, disposed to give a more or less uniform heating of the said tube. Pyrolyzed mixture leaves the tube' 24, passes-through a fitting 29, and enters pipes 30, 14, and 15 which may convey it to. a cooler, quencher or other device 43, which itvfenters at a point 32. The said pipes 30, 14,, and 15 are preferably water-jacketed .or otherwise cooled,

and preferably both fittings 23 and 29 are of indication of such instruments in Fig. 1 has merely been for the purposes of illustration and is not to be construed as limiting my invention.

The means 43 is according to the embodiment shown, preferably a tower fitted with water connections such as 34, 35, and 33, each of these having a valve as indicated for adjustment, and a spray device 64 within the tower in operating relation to the said water connection and valve. I

The pyrolyzed materials cooled by the pipe 30, on entering tower 43, at 32, maybe suddenly chilled by the water sprays within. At the same time any diluent, if of boiling point substantially higher than that of the final gas temperature in the tower, will for the most part be condensed. Together with such diluent, will be removed from the cracked mixture, the greater part of any high boiling materials such as oil, asphalt or tar vapors, particles of solid organic matter, and par ticles of carbon that the said products may contain as a result of the pyrolysis operation in tube 24. Such material removed by the liquid spray will generally be in a fluid condition, making possible its removal from the tower at will, as through the liquid seal 44.

- Cooled pyrolyzed materials make exit from tower 43 at a point 33, containing perhaps residues also of liquid and solid by-products. Pyrolyzed gas. will be so termed herein till reaching the point 41 of the unit 43, regardless of intermediate changes in its character. Filters 31' and 31, are provided where there are removed particles of oil and asphalt fog, and particles of solid organic matter and carbon. Deposit in the filters may be removed by steaming, hence filtration is carried out in onefllter while steaming the other. Steam connections are not shown, nor will alternate operation of the filters be detailed. An oil scrubber 36 may be provided which removes from the materials traces of the same kinds of deposits caught by the filters 31. The said scrubber is not detailed, but circulates an oil that makes intimate contact with the gas in a conventional manner and takes to itself further heavy impurities in the gas.

Beyond the oil scrubber l6 and connected therewith is the suction end of the pump 69,

whose full function is to be explained later. 1| is a valve for by-passing part of the discharge of pump 69. The said valve 1|. is operated by pressures in chambers 23 and 63 communicating through pipes 12 and 13, respectively. The purpose of this valve 1| is to maintain a desired ratio between the pressures in the chambers 23 and 63. From the exit end of the pump 63, the materials may be passed through a meter 46, a gas holder 85, and then preferably through a dryer 6! for removing traces of any liquids for the most part condensed in the quencher 43.

In combination with my apparatus may be one or more units 48, for treating the products produced in the pyrolysis apparatus. These units which may comprise scrubbing towers, absorbers and the like, may be connected with one another, and with the remainder of the system by conduits 41, 53 and 83. Conduits 83 and 53 may lead back to the pyrolysis apparatus as shown for recycling materials to the quencher 43 or other units. For example. the liquid used in treating the products produced might also be satisfactory as a cooling medium to supply to the quencher 43. By my apparatus arrangement such a liquid might be used in 43, conducted to 43 and further used.

Such an arrangement assists in eliminating losses.

It should be repeated that Fig. 1 does not show each of the units of the process in its exact form, but diagrammatically. More particularly is this points at which I would prefer to apply apparatus to accomplish 'separations,'purification, or other treatment desired.

As indicated, I have provided apparatus to circulate some orall of products-produced, allowing them to pass through valve 51 and the meter 56, so that they may enter pipe 60 which communicates with the point of juncture where is fed the original stock. In the case of such recirculation, then, necessarily the raw material to be pyrolyzed consists of. mixed stock in the proportion as indicated on the meters 4, 56 and 59. It is clear that each of the said stocks at the flue gases issuing from the preheater l6 and the by-pass 39. In the first case of course, the burners 25 should be in gas-tight relation to the furnace 42, while the said furnace in turn must be made to withstand the slight internal pressure needed to force the flue gases through the tunnel 65 as desired. In the second case the housing 38 of the preheater l6, and the stack (not shown) which receives flue gas from the by-pass 39, must be designed to deliver to a source of suction the gases passing through them. At the same time the furnace and connected chambershandling flue gas, must be sufliciently strong to withstand the suction applied, as is well known to those skilled in the art. A

In the precedingparagraphs I have described in detail a complete assembly for my high temperature apparatus together with its associated parts such as feeding mechanism thereto, a preheater and means for controlling or otherwise treating the materials produced in the pyrolysis tube. As indicated above, one feature in the high temperature apparatus under description which requires particular consideration is my provision for assembling the heating conduit,

with other conduits, the furnace wall and associated parts in order to obtain a gas-tight relationship, yet provide a construction which under heating to extremely high temperatures does not break, crack or otherwise fail. For a more complete understanding of this feature of my invention, reference is made in particular to Fig. 2.

Fig. 2 shows in considerable detail a tube unit such as might be employed in Fig. 1, as at 23, 24, 29 and the manner in which these are assembled for accomplishing to best advantage the purposes of the said parts, separately and in conjunction.

, The said tube is shown connected to fittings bottom and top for receiving and delivering the material being processed. At 204 is shown the baseplate of the furnace, in which may be built a refractory housing'as indicated at 205. The region 206 then forms the combustion space encircling the tube 203 and corresponds therefore with the space 63 of the furnace 42 of Fig. 1.

In Fig. 2 again, the tube 203 at its lower end is preferably spherically ground to fit a seat of spherical shape 2l8,and the said tube rests thereon in such a way that if it is-tilted slightly from the vertical, there results but a slight sliding of two substantially concentric spherical areas that maintain snug contact, as is of course desaid cooperating surfaces, a gasket such'as of tionship as well as to facilitate the sliding of the surfaces. flanged fitting 2 I 5 which is made fast to a flanged hollow ring 252 by means of a plurality of capscrews 2l6. The seat may beintegral with the water-cooled casting, if desired. The annular chamber 2l3 carries water for water-cooling.

turn has a flange 2 l0 which is made fast to a flange 2| I through the agency of a plurality of shouldered studs 214 co- The said hollow ring 252 in operating with nut 253. Flange 2 becomes part of the furnace base-plate 204 by virtue of the The said seat 2l8 is formed in a collar 254 which is integral with both. The said they are in operating relationship, the upper faces of the base-plate 204 and the hollow ring 252 substantially coincide. At the same time, water conection from the ring 252 to the outside is made through nipples 2I2 and 2H threaded into the said ring. The said nipples pass preferably through holes formed in the collar 254, to be threaded into the hollow ring 252 as shown, in water-tight relationship. 4

At 201 is a housing made fast to the studs 214 through the agency of nuts that draw up the flange 209 of the housing 201 against the flange 210 of the hollow ring252, in' gas-tight operating relationship, as preferably with a gasket between them.- At 208 is a nipple integral with the housing 201 that connects with conduit 22 from the preheater IG- of Fig. 1.

Referring again to Fig. 2, the flanged fitting of diameter for fitting within the hole in the flanged fitting 2l5, and adapted. to rest squarelyon the shoulder 222 of the fitting. The thimble 255 at its upper end is approximately spherical,

but contains perforations .251 for making communication from the housing 201 to the annular chamber 248 between the corebuster 2 I9 and the tube 203. The said thimble with its perforations thus may form a sort of spider that can support at its top the weight of the corebuster, while at the same time giving passage to materials from the inside of housing 201 to thean'nular chamber 240.

The corebuster indicated at 2l9 can be of any of a number of different shapes, but is here shown cylindrical, and concentrically placed in the tube .203 by virtue of lugs 241 integral'with each corebuster section. However, as will be pointed out hereinafter, there will be a definite area relationship in the unit. There may be a hole 224 in the corebuster. axially concentric therewith, for the purpose of admitting a thermocouple or other devices therein.

In Fig. 2 again, the upper end of the tube 203 abuts a shoulder 258 integral with atube-portion rugated flexible tube 240. The said flexible tube 240 ,in turn is made gas-tightat its far end, to

the flange 24I' which in turn serves for making connections to piping, as for instancethe pipe of Fig. 1. Thus as in Fig. 1 the materials may be carried from the pyrolysis-tube 24 tothe quencher 43 as described above. I I Q 243 is also substantially concentric with th corebuster 2l9 within the. tube 203, and thus serves for a means of introducing a thermocouple or other device within the corebuster as already referred to.

Gas-tight relationship between the cracking tube 203 and the tube-portion 225 is made through the gland 228 surrounding the said tube 203 and surrounded by a cylindrical wall 226 which is integral with the shoulder 258. Between the tube 203 and the wall 226 is a suitable packing 221, preferably of asbestos, which effects gastight cooperation between tube 203 and the tubeportion 225 by virtue of pressure exerted on said packing by the gland 226.

The wall 226 is integral with a flange 266 which in turn is integral with a cylindrical wall 229 of substantially larger diameter than that of the wall 226, and surrounding it so as to form an annular space 250. The said wall 229 also extends beyond the upper end of said wall 226, and is integral with an internal flange 260. The

said flange 260 has a hole of diameter appreciably larger than the outside diameter of tubeportion 225, and concentric therewith, so that the'said tube-portion may extend through the said flange without touching it, and in fact with the benefit of considerable clearance for reasons to be set out.

Coaxially integral with the internal flange 266 are two concentric tube- portions 230 and 23! the former having an internal diameter preferably that of the hole in the said flange 260, and the latter having an internal diameter approximately midway of those of the said tube-portion 230 and the cylindrical wall 229. Thus there is formed between the two tube- portions 230 and 238, an annular trough to serve as a seal in cooperation with-a vertical tube 231 of diameter suitable for fitting loosely therein. The said tube 231 extends upwardly where a tube 238 of preferably the same diameter as tube 231, communicates therewith in a convention pipe-T relationship. The said tube 238 is further located at a point to be concentric with the flexible tube 240, and at its free end makes integral connection with the flange 24l. With this spatial relationship,'the vertical tube 231 extends well down into the trough 232, not so far as to touch the bottom of it, but in fact allowing considerable clearance, again for reasons to be made clear.

The flange 260, towards its outen edge, that is, beyond the tube-portion 23! offers a shoulder to receive a flange 236 loosely thereon. The said flange 236 has an external diameter considerably greater than that of the tube-wall 229, and approximately that of the flange 249 of the packing-gland 223. While the said gland flange 249 has a plurality of studs 234 integral therewith and extending upwardly and spaced approximately equally in a circle about the wall 229, the flange 236 has a circle of holes toward its outer edge consecutively coaxial with the said studs 234 so as to engage them. The upper threaded ends 263 of the said studs 234 pass through the said holes in the flange 236, so as to cooperate with nuts 235 that draw them upward. Thus is'the gland 223 upwardly thrust against the packing 221 as desired.

The foregoing description of the fitting 'made fast to the upper end of tube 203, makes it clear that there is free communication between the from the upper end of the tube 203 tothe flange 24!. To make the said jacket function, nipple 246, is supplied for making communication with the chamber 250 for admitting water, while nipple 242, communicating with chamber 265, serves as an overflow for exit water, and mercury or other seal 233 in the trough 232, completes the requirements. Water entering through nipple 246 fills chambers 250, 264, and 265 in order, and rises in tube 231 to the level 245 maintained by the overflow nipple 242. Mercury in the trough 232 acts as a seal and prevents water from escaping at that point. In this manner it is obvious that all the piping handling pyrolyzed mixture delivered by the upper end of the tube 203 is efiectively kept from burning, melting or otherwise depreciating. Particularly is this of advantage in the service of the corrugated tube 240, which necessarily is frail, butnevertheless important in assuring satisfactory service from the tube 203.

For it is to be expected that in the course of life of the tube 203, and particularly in beginning operations, there will be endwise expansion, and contraction, as well as bending and twisting according to the fortuitous demands of possible non-uniformity in'the tube material, and irregularity in firing of the furnace. It is herein considered to be obvious from the description of the assembly as shown in Fig. 2, in view of the detail presented in the said figure, how the tube 203, while being held in perfectly suitable gastight relationship with its lower and upper cooperating fittings, is yet free to follow any thermal motions to which it may be subject. For with the spherical seat 2I6 it is clear that the upper end of the tube 203 without difficulty may remain substantially concentric with the tube 231 at some point between their opposed ends. Consequently, my apparatus is suitable for carrying out processes requiring temperatures substantially greater than 1006 C.

Thus though the tube 203 at its upper end may be tilted due to bending, ample clearance is provided between tubes 225 and 231 so as to obviate binding between them, while obviously the end of the flexible tube 240 aifixed to the tube 256, follows the movements thereof. Twisting of tube 203 likewise is tolerated by the said flexible tube 260.

If desired, the assembly consisting of tubes 231 and 238, together with flange 248, may be counterweighted at a point indicated by the eye-bolt 266 integral with pipe 238. And if it is desired to relieve the weight resting on the tube 203 as described, this may be accomplished by counterweighting the assembly concerned at a point indicated by the eye 261 integral withthe thermocouple nipple 243.

Thus, in short, the combination of parts shown in- Fig. 2 and described, and cooperating as described, eliminate substantially all strain on the tube 203, with the one exception of compression at its upper end due to gland and packing. The value of this accomplishment will be clear when it is appreciated that heat resisting refractory ware such as may be used for tube 203, while in the service of being heated to 1000 C. or higher there is a severe temperature gradient not only through the Wall of the tube, but also axially along the wall.

It may be pointed out also that at the bottom till of tube! cooling may be limited to what is necessary for keeping the. gasketon the seat H8 in good condition. At the top of the tube, con- -versely, it may be desirable to perform asmuch cooling as possible, toassist in cooling and recovering .the desirable products. Fig. 2 is developed in sum'cient detail to make it obvious that wherein ratio of surface to volume will be expressed in square feet per cubic foot. For instance, in a preheater tube of 1.75 inches internal diameter, without corebuster, the said ratio might be If a corebuster is present, the sum of the internal areas exposed to the materials being pyrolyzed, is divided by-the net volume bounded by said areas.

' If the corebuster-is cylindrical, the-volume is then annular. If the outer surface of the corebuster has a special shape, the area of that surface is measured or estimated for use as above.

Ratio of area to volume, hereinafter to be termed area ratio, in the preheater tube may range from as much as 250 to as little as 5. I have found that the range permissible here may be varied, since it may be compensated not only with temperature, but also with residence period. For. the higher the area ratio, themore rapidly the sflswill absorb heat, the less severe the temperature need be, or the less the period of heating. Wide fluctuation of area ratio brings wide fluctuation of residence period, but not such a great variation of temperature. Hence, the temperature range remains nevertheless rather well fixed.

While discussingthe construction of my preheater, it is desired to point but that the preheater may be constructed of metal because it is not required to withstand such high temperatures as the pyrolysis tube. It is also apparent that the preheater is traversed by feed materials which are at a lower. temperature than the-products flowing in the pyrolysis tube, hence may be cooled somewhat by such feed. The preheater may be constructed of any of various tals of which may be mentioned chromesteels ontaining for example, between 15-40% chrome, chrome-aluminum steels containing from about 8-18% chromium, and a few per cent aluminum or-various other steels such as chrome-molybdenum, chrome tungsten or the like. It is also possible-to use chrome-nickel steels, and'other heat-resisting alloys'but the aforementioned types of materials are preferred.

Reference is now made to the interrelationships of variables in the apparatus shown in Fig. 2, for example.

Although any dense refractory of good heat conductivity and resistance to spalling may be.

' used as wall material for the tubes 203, I prefer superior mechanical condition. Whatever the material of the corebuster, it should not be such as not to slag down with the tube material.

I find that I can use tubes of any diameter, so long as I hold to a proper proportion of length to diameter, and to a reasonably light wall. The cgrebuster, if cylindrical, must be such as to maintain a reasonable range of clearance between corebuster and tube wall, r'egardles of tube diameter. If the corebuster is not cylindrical, as in Fig.5, it should be such as to p' "sent a similar range of path section as the said cylindrical corebuster. a

For example, a tube of 2-inch internal diameter may conveniently have a heated length of. 36 inches, and a wall thickness of A; inch, while the corebuster may be of from 1.0 to 1.80 inches diameter. A tube of 4 inches internal diameter may have a length of 6 feet exposed to the combustion chamber, a wall thickness of inch, and a corebuster of from 2.0 to 3.70 inches. Again, a tube of 8-inchinternal diameter may have an exposed length of 12 feet, a wall thickness of 1 inches, and a corebuster of from 4.0 to 7.60 inches.

The area ratios resulting from these assembly dimensions are, for the 2-inch tube, 48 to 240,

for the 4-inch tube 24 to 160, and for the 8-inch tube 12 to 120. Fairly large values of ratios are preferred. With the large tubes, itis preferred to employ the cylindrical corebuster, one of increased contact area such as shown in Fig. 4.

Particularly is this true in the hottest part of the tube. Thus for illustration, in a 4-inch internal diameter tube of V inch wall thickness, a. very suitfactorily and has considerable capacity. As

pointed out, by my type of construction, it is possible to employ tubes of a considerably larger pyrolysis apparatus on an enlarged scale, the unit llll may be of a circular type containing a plu- Referring now to Fig. 7 which represents my rality of vertical ceramic tubes. These tubesmay be the same construction as those described with respect to Fig. 2 and contain a corebuster. As

already indicated, one of the important features for consideration is my novel arrangement for supporting the tubes so as to assure tightness yet freedom of movement to providefor expansion.

It will be noted that in this unit, tubes maybe ground to fit a. water-cooled metal seat at I03, as described under Fig. 2. The top is connected in a non-rigid manner as at mil.

After the tubes have been inserted through holes I06, the roof may be placed in position and connections maile through the water-cooled packing gland I04 to which may be integrally connected water jacketed pipe III! which extends space.

up' to flange I08. This double walled cooled conduit is made flexible and free to move by the bellows construction I09. Cooling as shown serves several purposes. It makes possible a simple bellows construction for taking up movement of the tube. Also it providesa means for controlling the temperature of the products withfor distributing combustion air and another conduit H3 is provided for distributing fuel.

The shape of the chamber surrounding the tubes has been arranged to produce rapid combustion and great heat liberation. The velocity of flow of the heating gases is increased and heating improved by means of the radiant reflectors II6 which forms the reflected annular passageway immediately below the combustion The slots III and passageway H8 are provided for conducting the combustion gases from the unit to the various preheating equipment already shown and described in Fig. 1.

The head cqnstruction of this unit may be composed of a number of suspended refractory parts designated I2I. -A removable section I22 may be provided for inspection of the inside of the unit and, also may be opened to prevent explosion.

The bottom of the unit is provided with the inlet conduits I 23 which may be connected with conduit 22 of Fig. 1.

While in the preceding description vertical furnaces containing one or more pyrolysis tubes have been described, my invention has wider applications. The form of construction shown in Figs. 1-7 are preferred because it is possible, to

obtain better joint construction, weight distribu- I tion, freedom from sagging and other advantages. However, my invention may be carried. out in a horizontal type of furnace in accordance with the following description with respect to Fig. 8.

In Fig. 8, ISI represents furnace construction within which may be positioned one or gnore pyrolysis tubes or units I32. These tubes are of the same construction as those designated 3, 24 and I02 in Figs. 1, 2 and 7. They are positioned within the furnace wall in a firm but non-rigid manner similar to that already described. That i up movement, due to thermal distortion. Since this type of construction has already been. described to some extent and will be further described with respect to Fig. 9, added description at this point appears unnecessary. A plurality of conduits I 26 and III are provided for feeding the other end of the pyrolysis unit as at I44 is a chamber from which the products produced in the apparatus may be withdrawn through a cooled conduit I45. The connection of this conduit with the apparatus may be rendered movable in a manner already described with respect to previous connections. This conduit is connected with a quencher or scrubber I41 of a construction similar'todevice 43 of Fig. 1. This quencher I41 may be connected through conduit I48 with one or more scrubbers or other devices I49 for further treating the materials produced. Conduit I5I is provided for conducting the materials away from the last of these units. As in Fig. 1, the heating chamber I is interconnected by means of the line I52 to a pressure balancing device I53 which in turn is interconnected with the pyrolysis chamber by means of line I54. A pressure-regulating device is interconnected by means of line I55 with a by-pass mechanism I51, I58.

The functioning of this by-passing arrangement is the same as the parts 60, II, 16, 23, and 63 of Fig. 1, that is, as a further aid to providing apparatus in which the destruction thereof by high heating conditions is minimized. I have provided arrangement whereby the pressure inside of the pyrolysis unit may be equalized or maintained at some predetermined relationship with the pressure in the heating chamber. It is apparent that due to different temperature gradients there will also be different pressures developed within the apparatus at different points.

Referring to Fig. l, by my construction the pyrolyzed materials produced in the apparatus leaving the device 86 are picked up by pump 69 and may be ejected through the valve'80, which is open when starting the operation. The proper adjustment. is then made on stud IQ of the bypass valves II so as to hold the pressure within chamber 23 the same (or at any desired relationship) with respect to the combustion zone 53. Valve II, of course, performs this function by relieving suction on the pump 69 through the by-passing line through which it'operates. A similar function of the apparatus arrangement shown in Fig. 8 takes place.

Reference is now made to Fig. 9 wherein more detail is shown means for firmly yet non-rigidly connecting the pyrolysis unit into the furnace. I22 represents the tubes upon the end of which may be shrunk a steel sleeve IBI. of this steel sleeve flanges I and I64 may be welded or otherwise securely attached. To the end flanges a bellows construction I66 and I5! may be brazed or otherwise securely attached.

These bellows are also fastened to alarge central flange I" which encircles the pyrolysis unit as do the bellows and other members. This flange may be bolted to a tube sheet I'BSor other construction forming a part of the furnace wall. In this manner the tubes may be firmly attached to the furnace but at the same time be free to move suflicient for taking up expansion or other a distortion due to extreme heating. Conduit means Ill and I12 are provided for circulatin cooling fluid in the construction. a From a consideration of the various forms 0 my invention which have been shown, it will be.

observed that my novel apparatus possesses a number of advantages, a few of which are summarized below. In the constructions which I have shown, it will'be observed that the pyrolysis chamber is firmly positioned in the heating or combustion chamber,-'yet by virtue of my novel non-rigid construction is free to move sub- At either end stantially all planes. By this construction, extreme heating of the pyrolysis tube does not cause breakage thereof, pulling away from furnace walls, leakage and other defects encountered in prior art constructions. By my construction it is possible to employ pyrolysis tubes .of several inches in diameteras contrasted to the use of very small sized equipment in prior art constructions. Although as indicated, a single large tube construction functions satisfactorily. my invention may be employed on a larger scale and a number of pyrolysis units positioned within the heating chamber.

As a further aid to the maintenance of conditions wherein gas leakage, strains and other destructive influences on the apparatus may be minimized, I have provided the aforementioned pressure-regulating mechanism between the pyrolysis tubes and heating chamber.

M It is apparent, that in apparatus constructed for use at temperatures in excess of 800 C., the question of heat transfer and heating of the materials to be pyrolyzed is of considerable importance. As already pointed out, I have found certain important "area ratios for obtaining maximum efllciency. In my furnace construction I have provided means for obtaining such area ratios as well as means whereby the area ratios may be changed or varied.-

While the feature of preheating by means of flue gases is applied in a number of apparatuses, it will be noted that I have provided a construction wherein the preheateris out of radiative contact with the pyrolysis unit. I have found this to be'a desirable feature in apparatus operating at extremely high temperatures; otherwise the preheater might tend to cool the pyrolysis unit. 4

The functioning of my apparatus is more or less apparentfrom the preceding description. However, brief reference is made to'Flg. l for a consideration of the example which is set forth merely for the purposes of illustration and is not to be construed as a limitation of my invention. 4 Materials to be treated may be fed in through the several conduits shown, all joining at H and entering. the preheater through conduit lb. Among the materials which may be treated are the various hydrocarbons such as methane, ethane, propane, butane,,pentane, and the like. These materials may be mixed with steam, halogen or various other agents and may contain recycled materials supplied through 60. Materials fed in may include unsaturated compounds such as ethylene, propylene, and the like. The

feed is preheated in the preheater and from, the

preheater pass through conduit 22 into the inain pyrolysis chamber. It is, of course, apparent thata higher preheat, for example, in the neighborhood of 800-l000 C. alleviates to some ex,- tent the degree of heating necessary'in the pyrolysis unit. Pyrolysis unit 24 may be heated by means of a burner 28 to a temperature in excess of 1000 C., say, for example, in the neighborhood of 1400 C. :Such heating together with control of residence period in the pyrolysis unit will bring about various chemical changes depending upon the particular process being carried out and'the exit products leaving the apparatus through conduit M may contain one' or more'of the materials, acetylene, benzene, naphthalene, oleflnes such as ethylene.) propylene and the like. The

material or various materials produced may be cooled, separated or otherwise processed in thevarious units 43 and 40. Certain of the residual components may be recirculated as already indicated.

While my apparatus is particularly suitable for converting saturated hydroearbons'to unsaturat-' ed compounds, it is apparent from the preceding l that my invention has a number of other uses. hence, I do not wish to be restricted, except insofar as may be necessitated by the prior art and the spirit of the appended claims.

What I claim is: 10 1. Apparatus for the continuous treatment ofmaterials at temperatures in excess of 800 C., which comprises a furnace having a heating chamber with at least one exit passage there-- from, a preheater in an exit passage connected 15 through a trap with at least one refractory pyrolysis tube of a diameter greater than one inch in the heating chamber, the preheater and pyrolysis unit being positioned out of substantial radiative contact with one another, means asso- Q ciated with the pyrolysis tube for fastening it to the furnace and to other elements in a gas-tight, non-rigid manner whereby temperatures in excess of 1100 C.' may be applied thereto, said means including a double wall construction "hav- 28 ing a flexible bellows therein, thereby forming a chamber in which cooling fluid may be circulated,

, conduits leadingv to a plurality of units for treating the products produced in the apparatus, and

return conduits leading to the apparatus from at 80 least some of these treating units.

) 2. Apparatus for heating materials to high.

temperatures, which comprises a furnace having a heating chamber, a pyrolysis tubehaving'a diameter greater than two inches, extending with the apparatus for maintaining the pressure within the pyrolysis chamber at a predetermined relationship, with the pressure exterior thereof.

'3. Apparatus for the thermal treatment of. materials to temperatures in excess of 800 0., which comprises a furnace having heating chamber with exit passages therefrom, a preheater having an area-ratio between 27-600, in an exit passage connected with at least one refractory pyrolysis unit having an area-ratio between 48-400, in 85 theheating chamber, the preheater and pyrolysis unit being positioned out of substantially radiative contact with one another, means associated 'with the pyrolysis unit for fastening it to the furnace and-to,other conduits in a gas-tight, W non-rigid manner whereby temperatures in excess of 800 C. may be applied thereto, said means comprising a double wall construction having a flexible bellows therein in which cooling fluid maybe circulated; aplurality of units for treat- 05 ing' the products produced in the apparatus, and

return conduits leading to the apparatus from at least some of these treating units.

4. Apparatus for the thermal treatment of gaseous hydrocarbon-containing materials to temperatures in excess of 800 0., which comprises a furnace having heatingchamber with exit passages therefrom, a preheater having an area-ratio between 25-100, in an exit passage connected through a trap with at least one re- 1' fractory pyrolysis unit having an area-ratio between 100400, in said heating chamber, means associated with the pyrolysis unit for fastening it to the furnace and toother conduits in a gastight, non-rigid manner whereby temperatures in excess of 800 C. may be applied thereto, said means comprising a double wallconstruction having a flexible bellows therein to form a chamber in which cooling fluid may be circulated.

5. Apparatus for carrying out a thermal treatment at temperatures in excess of 800 C., which comprises a. furnace having a heating chamber with at least one exit passage'therefrom, a preheater in an exit passage connected with at least one refractory pyrolysis unit in the heating chamber, means associated with the pyrolysis unit for fastening it to the furnace and to other conduits in a gas-tight, non-rigid manner whereby temperatures in excess of 800 C. may be applied thereto, said means comprising a spherical seat receiving one end of the pyrolysis unit, a hollow ring adapted for circulation of cooling fluid encircling the jointure, means on the hollow ring for the connection thereof with the seat, furnace and other parts, a metal conduit which terminates'in a shoulder and flange, said shoulder and flangev abutting and embracing the other end of the pyrolysis unit, a gland containing packing between the pyrolysis unit and flange, concentric collar means for exerting pressure on the packing and firmly connecting the unit with the furnace, a double wall construction having a flexible bellows therein, comprising at least a portion of the metal conduit to form a chamber-in which cooling fluid may be circulated, and an outlet conduit leading from the apparatus.

6. Apparatus for heating materials to temperatures greater than 1000 C.; which comprises a furnace having a heating chamber, a pyrolysis tube having a diameter greater than one inch and having an area-ratio between about -400; extending through the chamber and at least partiallythrough the furnace walls, -means associated with both the furnace and tube for holding the tube in a firm but non-rigid manner so that high heat may be applied to the tube without material dislodgment thereof from attachment to the walls, said means including a double wall construction having a bellows therein and inlet and outlet conduits leading to the apparatus.

7. Apparatus for heating materials to high temperatures, which comprises a furnace having a heating chamber, a vertical-refractory pyrolysis tube extending through the chamber and at least partially through the furnace -walls, means associated with both the furnace and tube for holding the tube in a firm but non-rigid manner, said means including a double wall con-- struction having a flexible bellows in the inside wall and a metal seal on the outside wall.

8. Apparatus for thermal treatment at ternperatures in excess of 800 C., which comprises a furnace having a heating chamber with exit passages therefrom, a preheater in an exit passage connected through a trap with atleastone vertically extending refractory pyrolysis unit having a diameter greater than two inches in said heating chamber, the preheater and pyrolysis unit being positioned out of substantially radiative contact with one another, means associated with the pyrolysis unit for fastening it to the furnace and to other conduits in a gas-tight, non-rigid manner whereby temperatures in excess of 1000 C. may be applied thereto, said means comprising a cooled spherical seat and a double wall construction having a flexible member therein.

9. Apparatus which comprises a furnace having heating chamber with exit passages therefrom, a preheater in an exit passage connected with at least one vertically-extending refractory pyrolysis unit in said heating chamber, a plurality of feed conduits connected to the preheater, means associated with the pyrolysis unit for fastening it to the furnace and to other conduits I 'with the hollow ring for the connection thereof with the seat and furnace, a metal conduit which terminates in a shoulder and flange, said shoulder and flange abutting and embracing the upper end of the pyrolysis unit, a gland containing packing between the pyrolysis unit and flange, concentric collar means for exerting pressure on the packing and connecting the unit with a furnace, said conduit comprising a chamber in which cooling fluid may be circulated, another metal conduit connecting the first-mentioned metal conduit and leading to a quencher unit for treating the products produced in the apparatus, and at least one return conduit leading to the feed conduits.

10. 'Apparatus for high temperature use, which comprises a furnace having a heating chamber with at least one exit passage therefrom, a preheater in an exit passage, connected with at least one horizontally extending refractory pyrolysis tube in the heating chamber, means associated with thepyrolysis tube for fastening it to the furnace and to other elementsin'asul; stantially gas-tight, non-rigid manner, said means including a flexible double wall construction attached. to the tube, thereby forming a chamber in which cooling water may be'.circulated, which construction is free to move with respect to the furnace, conduits associated with said construction for supplying the water, and

conduits leading to a plurality of units for treating the products produced in the apparatus.

11. Apparatus for 'heating' materials to high temperatures, which comprises a vertical furnace having a heating chamber, a vertical pyrolysis 0 tube extending through the chamber, a spider member positioned in the lower portion of said tube, the pyrolysis tube including a refractory corebuster having protrusions thereon for positioning the corebuster in spaced relation from the chamber supported on the spider, means associated' with both the furnace and pyrolysis chamber for holding it in a firm but non-rigid manner so that high heat may be applied thereto, said means including a non-rigid double wall construction in which fluid may be circulated and conduits connected therewith for supplying and withdrawing said fluid.

. RUDOLPH LEONARD HASCHE.

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