US1794542A - Distilling hydrocarbons - Google Patents

Description

March 3, 1931. E. PIRON- l y 1,794,542

DISTILLING HYDRocARBoNs Filed Jan. 20, 1927 @3nd, f

Patented Mar. 3, 1931 'EMIL PIRON, OF NEW YORK, N. Y.

DISTILLING HYDROCARBONS v Application filed January 20, 1927. Serial No. 162,224.

This invention relates to the process of distilling solid or liquid hydrocarbons, or both,

and forming coke as a residue, as Well as re-' covering valuable volatile products. y

In carrying out this invention, metal blocks or the like, preferably in a series in the form of a chain or conveyor, are heated `to suitable temperatures and passed through a distillaltion zone where the hydrocarbons are applied thereto in thin layers and distilled. The heat stored in the blocks distills the hydrocarbons and forms a residue or coke, which is later removed from the blocks and the volatile products obtained by the distillation may be recovered and used. Heretofore, in carrying out distillation processes in this manner, it has been found that with certain hydrocarbons and with temperatures to which the metal blocks have been heated, objectionable over-cracking ofthe volatile products sometimes takes place, due to the fact that'the temperature to which the metal blocks must be heated to produce coke of suiicient dryness causes the volatile products to contact with surfaces that are so hot as to injuriously effect the same by cracking to an undesirable extent.

By the present'invention this objection is overcome and aV residue of coke of the desired degree of dryness can be obtained without .causing an appreciable amount of cracking of the volatile hydrocarbons. In carrying out thisinvention the metal blocks are heated to temperatures sufficiently high to cause the desired result when the hydrocarbons are contacted with the surfaces thereof, and at the same time the heat that is stored in lthe interior portions of the metal becomes available for bringin the residue from the distillation up t`o the esired temperature. The metal blocks are removed from the distillation zone before the volatile constituents have been permitted to become overheated by contactwith the hot metallic surfaces for an appreciable length of time. The invention may be practiced by contacting the hydrocarbons with the hot metal surfaces whose temperature becomes quickly lowered while the hydrocarbons are being distilled and a residue formed, and after this irst layer of hydrocarbons has been brought into contact with the hot surface and the distillation process has cooled the same and then the interior heat has again increased the temperature of the residue, another thin layer of hydrocarbons may be applied to the residue and become distilled vleaving more residue, thus'preventing contact of metallic surfaces of too high temperatures with the Volatile constituents. Following the last application of hydrocarbons and the distillation thereof, the blocks are removed from the distillation zone as the temperature of the residue approaches the danger point so far as over-cracking of the distillates is concerned.

In the accompanying drawings is illustrated somewhat diagrammatically, an arrangement of apparatus by which the invention. can be carried out. In the drawings, Fi. 1 is a vertical section through the device, an Fig. 2 is a section along the line 2 2 of Fig. 1. Reference character 5 indicates the housing within which'the apparatus is enclosed. Sprocket rollers 6 and 7 are mounted on shafts 8 and 9 in the housing, and one or both isy driven in any convenient manner so as to revolve in the direction of the arrows. A conveyor or chain made up of a series of flat metal blocks 10 pivoted together as indicated at 11, passes around the sprocket rollers 6 and 7, and is driven by the sprocket teeth 12 pro- 'jecting into notches or openings 13 in the blocks 10.

A series of thick Walls or partitions 15 are provided in the lower part of the housing and gas jets or hot products of combustion may be introriluced into the spaces between the walls l5 to heat the blocks 10. A spout or inlet 16 is provided above the sprocket 6 for feedingr hydrocarbons onto the conveyor or heated blocks. This spout may be provided with a damper 17, or other means to regulate the rate of feed of the hydrocarbons, or the lower end thereof may be spaced the desired distance from the upper Surface of the blocks 10 to cause a layer of the proper thickness to be fed to the blocks. One ormore inlets 18 providedwith -valves 19 may be provided between the sprockets 6 and 7 from the lower cross pipe 20 of which hydrocarbons may be fed to the conveyor. An outlet 21 is provided in the housing through which the volatile products may be withdrawn and then condensed or used. A scraper 22 is provided as y indicated to remove the major portion of the residue from the blocks 10 and the remainder of the residue may be scraped or worn off by the blocks sliding along the top surfaces of the walls 15. A support 23 may be provided between the sprocket rollers 6 and 7 beneath the upper run of the conveyor, upon which support the blocks may slide while the distillation of the hydrocarbons takes place.

Either solid hydrocarbons, such as coal, or liquid hydrocarbons, such as petroleum, tar, etc., may be distilled, or a thin layer of either one may first be' applied to the blocks and a residue formed, after which a subsequent layer or layers ofeither solid or liquid hydrocarbons may be applied further along in the distillation zone at one or morepoints, to absorb the temperature of the residual layer and prevent it passing a temperature capable of over-cracking the freed volatile products in the distillation zone. Y l

It has been found that it is desirable'to have `the residue or coke to contain not more than about 20% of volatile matter, and in order to do this it is necessary to heat the metal blocks between about 1050o and 13500 F., in which case the vapors of distillation will have temperatures from about 800 to 10000 F. when petroleum oil is being distilled. It has been found that under these conditions, the metal blocks can be passed through the combustion chamber at a sufliciently rapid rate to prevent their surfaces from reaching such high temperatures after the distillation has taken place as to injure the vapors to an appreciable extent by cracking the same to an undesirable extent. I

As will beunderstood', the general cycle of operation of the process is as follows :A

At the time when the first layer is brought into contact with the surface'. of thesupporting plate, the latter is at its maximum temperature whilethe hydrocarbon is at its low temperature, thusvproducing the conditions of a maximum temperature differential between the plate and layer.- Under these conditions, there is a rapid heat exchange action from the plate to the layer, resulting in an incidental'loss of heat at the plate surface,

and a gradual decrease in the temperature 'differential between the. layer and surface,

thus setting up the temperature conditions in the layer for lproducing the various distillation results, and at the same time providing a layer of residue which is in direct contact with the plate surface. If these conditions were permitted to continueuntil the differential was eliminated, the temperature of the layer would be raised to a degree which would tend to produce over-cracking of the distillates, since the stored heat of t e plate would tend to constantly restore the plate surface to heat equality with the body of the plate, the continued decrease in differential permitting this condition to develop until the layer and plate were of approximately. equal temperatures.

However, at an intermediate point in the progress of this differential decrease, the second layer isadded to that of the first, thus bringing the colder layer into direct contact with the first layer, with the result thatv the temperature differential decrease between the plate and the first layer is checked, and setting up the conditions of a composite layer inv which the superposed part acts as a. deterrent against a too rapid lde-velopmentof the differential between the plate and the first layer,'while the heat exchange between the first and second layers is active in producing the distilling effect upon the second layer. As a result the development of the differentialdecrease between the second layer and the plate is accomplished at a slower rate and without subjecting the first layer to excessive temperature Iconditions such as would affect over-cracking conditi/ons of the distillates of thel first layer. Since y'the rate of differential decrease is thus made slower, itis possible to readily control the time when the composite layer is taken from the plate, and thus enable such removal or addition of another thin layer to take place prior to the time when the differential decrease might reach a point Where overcracking would ensue.

The process thus provides a rapid development of distillation during-early stages of the action on the first layer, and then a chan e in the conditions of that layer which chec s the development of the later stages of distillation of that layer, and at the same time provides for a gradual development of .the distillation stages of the second layer, with the composite layer kept from producing the conditions of over-cracking.l Since the more highly volatile components of the first layer have left the latter before the second layer is added, it will be understood that the distillation products remaining in the first layer posite layer or the addition of further layers and then removal, it will be understood that over-cracking conditions are substantially eliminated.

And since there is a layer of residue 'in contact with the plate itself, it can be readily seen that over-cracking of distillates through contact with the'plate itself is prevented.

I claim: 1. The process of distilling hydrocarbons which consists in applying a layer of hydrocarbons toa moving surface, 1n conducting /said surface through a distlllation zone ducting said surface with said layer through a Izone for collecting the distillate resulting from 4the heat exchange between said surface and said layer, in positivelyv checking the distillation of Said layer by adding a further layer after a predetermined period of time in said zone, and in then removing said surface with the residue of both layers from said zone.

3. The process of distilling hydrocarbons which consists in applying a layer of hydrocarbons to a heated moving surface, in conducting said surface with said layer through a zone for collecting the distillate resulting from the heat exchange between said surface and said layer, in positively checking the heat exchange between the residue of said layer and the distillate in said zone after a predetermined time interval of said surface and said layer in said zone by adding a further layer whereby the distillate in said zone will not be cracked, and in then removing said surface and said residue from said zone.

4. The process of distilling hydrocarbons which consists inapplying a layer of hydrocarbons to a heated moving surface, in conducting said surface with said layer through a zone for collecting the distillate resulting from the heat exchange between said surface and said layer, in blanketing the residue of said layer with a heat absorbing means comprising a further layer whereby the distillation of the residue of said layer ceases pending attainment of a temperature in the heat absorbing means equal to that of said residue and whereby heat exchange between said residue and said distillate is likewise suspended pending reattainment of maximum temperature-by the residue of both layers and in removing the composite residue from the distillation zone upon attainment of the maximum temperature.

5. The'process of distilling liquid hydrocarbons which consists in spraying such a thin layer of hydrocarbons on a hot plate that the distillation begins at a temperature approaching the temperature of the plate whereby intermediate distillation products are avoided, in allowing the products of distillation to escape until the residue on said plate has attained a predetermined temperature and constituency, in adding a, further layer of hydrocarbons to said residue before the maximum temperature attained by the residue. has contacted the products of distillation beyond an infinitesimal period of time, in allowing the products of distillation resulting in heat exchange between the residue and the second layer to escape and in removing thc residue of both layers prior to prolonged exposition of the distillate of the second layer to the residue after the attainment of maximum temperature thereby.

y 6. The process of distilling liquid hydrocarbons which consists4 in spraying a thin layer of hydrocarbons on a metallic surface heated to a temperature between 11000 and 1200o F. whereby the heat exchange between the plate and the layer as a whole will be so rapid as to substantially begin distillation of the layer at approximately`800o l". thereby substantially eliminating the classes of distillate occuring below 800 F., in allowing distillate and fractions to esca-pe until the residue of the layer attains a ternperature substantially equal to that of the plate, in adding another thin layer of hydrocarbons to the residue of the first layer prior to prolonged exposition of the distillate to the radiated heat from the maximum temperature of the residue, and in removing the composite residue of both layers prior to prolonged exposition of the distillate from the second layer to the maximum temperature attainable by the residue therefrom.

7. The process of distilling hydrocarbons which consists in bringing a thin layer of the hydrocarbon into contact with the surface of a heated support when the temperatures of hydrocarbon and support are at maximumV temperature differential to thereby obtain rapid heat exchange action from the support surface to thelayer and effect distillation activity of the'layer to produce distillation products and a residue layer, then applying a second layer of hydrocarbon on to the -residue layer when the temperature diiferential of the first layer and support has been decreased approximately to a predetermined value, and then subJecting the composite layer to the heat action of the support for a predetermined period, whereby the later applied layer will check reduction of the te-mperature differential of the first layer and prevent over-cracking of distillates of that layer, and the continued heat application will complete the distillation of the composite layer.

8. A process as in claim 7 wherein he support is of heat-storage characteristic and movable to permit continuous repetitions of the process cycle with the residue of the composite layer removed from the support prior to a decrease in' temperature differential loe-'- the progression of the tween support and composite layer suiicient to produce over-cracking of the distillates.

9. The process of distilling hydrocarbons which comprises applying a thin layer of said hydrocarbons to a moving surface heated to effect the freeing of Volatile products from said hydrocarbons whereby a residue is left y on said surface, and adding to said residue `further hydrocarbons when the volatile prod- -ucts have been freed to a substantially predetermined extent.

10. The process of distilling hydrocarbons which comprises applying a thm layer of said hydrocarbons to a heated moving surface and retaining said` layer of hydrocarbons in distillation zone subject to the heat of said surface until the resulting residual layer ap-l proaches a temperature capable of overcracking the freed volatile products, and then i applying to said residual layer further hydrocarbons to absorb the temperature of said residual layer.

11. The process of distilling hydrocarbons which comprises applying a thin layer of said hydrocarbons to a heated surface to effect the freeing of volatile products from said hydrocarbons whereby a residue is left on said surface, adding to said residue further hydrocarbons when the volatile products have been freed to a substantially predetermined extent, and subsequently removing said surface from the distillation zone ,before its tem erature approaches that capable of over-crac ing the freed volatile products.

12. The process of distilling hydrocarbons which comprises applying a thin layer of said hydrocarbons to a heated moving surface permitting volatile products to escape and leave a residue and applying another layer of hydrocarbons to said residue at another point of travel of said surface in the distillation zone.

13. The process of distilling hydrocarbons which comprises applying a thin layer of said hydrocarbons to aheated moving metal surface permitting volatile products to escape and leave a residue, and applyin another layer of hydrocarbons to said resi ue at another point of travel of said surface in the distillation zone after the temperature of said residue has been increased by heat that had been stored in the metal below the surface thereof and before that increase of temperature has injuriously affected the distillation products.

EMIL PIRON.

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