US 2372591 A
Description (OCR text may contain errors)
M r 1945? H. E. LONNGRIYIN 7 2,372,591
METHOD AND MEANS OF CRACKING PETROLEUM O ILS Filed April 3, 1943 'EQRA LD ELONNGREN INVENTOR ATTORNEY carryingfluid.
Patented Mar. 27, 1945 UNITED STATES PATENT OFFICE 7 METHOD AND MEANS OF (IQACKING PETROLEUIVI OILS Claims.
My invention relatesbto methodsv and means tor cracking petroleum oil and has particular reference; to the art ofcracking: in which heat, required for the conversion of hydrocarbons, is transmitted. directly to the treated oils Without the-useiof coiledlpipes andzpipe stills.
One of the serious disadvantages of. ordinar cracking processes is that the treated oil must pass through. relatively long; pipes in order to obtain. more efficient heat exchange. Petroleum I when the production is-limited.
oils, however, when heated under cracking conditions; precipitate coke. and other hard residues andproducts of condensation, which rapidly clog the pipes and prevent efficient operation of the system.
\ generally tangential or oblique direction.
Another object. Of? my invention. is to provide an it arrangement whereby thecracking heat" is communicated tothe oil directly by means of a suitable-gaseousheat carrier, for which purpose the oil-is introduced 111130113116 cracking chamber in ceives its-heat through direct contact with the heatcarrier, without/the: use of intervening or transferring-mediums The material-therefore reseparating; metal walls aslin'ordinary pipe stills.
The heatexchange takes place, therefore, rapidly andeiliciently, due tothe very large surface area of, the. minute particles of oil, each individual particle receivingits share. of. heat directly from immediately surrounding, particles of the heat Another objectofz my invention is to provide means,v to... produce turbulence in the cracking chamberfor. more efiicient interchange. of heat between. the oilparticles and the heat, carrying fluidl. I.pro.vide for this-purpose atomizing and sprayinge nozzles for the chamber which direct thesprays eccentrically. or obliquely to the axis ofithe chamber, thereby creating a'whirling turbulent body ofrthev atomized 01-1., I, also provide meansto. direct the-jets-ofthe inert'fluid in a -t0.maintain the process under 'controlby regulatingthe.relative-amounts of oil and fluid, also theyelocityof their movement" My system hasan importantadvantage in that I the crackingwessel .can be. made. of; any suitable form. and can be mounted. either; vertically, or horizon-tal1y --as.-the spacepermits, since the process does not depend on gravity or other factors, limiting the design andv position of the parts.
Another advanatge of my process is that it can be carried with equal success in large vessels for large production or in relatively small containers Another object of my invention i to provid means to maintain the walls of the cracking vessel free from coke and other hard sediment. I provide for this purpose a jacket around the Vessel with nozzles extending inward from the jacket at an angle to the axisof the vessel in a The nozzles are so arranged that the issuing jets of superheated steam or other fiuidmove along the Walls, blowing off anysediments which may be settled or precipitated thereon. Still another object of; my invention is to provide means to remove any small solid particles from the cracked gases issuing. from the vessel. I provide for this purpose a spray of oil or other suitable liquid in the pass of. the exhaust gases, the liquid being delivered inthe form of a plurality of fine spraysforming acurtain or screen, effectively entraining all the solid-particles from the gases.
My invention in one of its practical embodiments is described more fully in the accompanying specification anddrawing in which:
Fig. 1 is an elevationalview partly in section of my cracking vessel; showing atomizers for the oil to be treated, also' nozzlesfor the hot fluid; coke removing curtain-forming arrangement, and other details.
Fig. 2 is asectional viewtaken on the line 220f Fig; 1.
Fig. 3 is asectional view taken on the'line 33 of Fig. 1. 1
.My cracking apparatus consists of an inner shell lfand an outer shell 2; preferably of cylindrical shape with. closed end portions 3 and 4'. Petroleum oil orother liquid hydrocarbon tobe cracked is introduced into the vessel" through atomizing nozzles -5, 5:
The nozzles may be-of' any ordinary'constr'uction in which aliquid is finely dispersed bythe action of compressed air or steam; The nozzles are fitted in the inner and outer shell andextend in a generally tangential or oblique direction with reference to the inner portionsof the vessel. As a result, the atomizersform a-fine mist inthe vessel, whirling in a plane perpendicular to the axis of thevessel.
A suitable inert heat-carrier such assuper heated steam or other suitable elastic fluid, is in troduced into the'vesselthrough a-cen't'ral pipe 6, supported axially of thev'essel and clos'e'd at the inner end 1, the outer end being connected to a suitable suppIy'pipe-B: The-pipe Grisprov'ided with radial projections 9 having apertures I!) through which steam emergesinaplurality of fine jets. The apertures ID are directed in a substantially tangential direction to the pipe 6, so that the jets form a whirling body in the vessel, rotating, in the same direction as the mist, formed by the nozzles 5. Steam thus is brought into an intimate contact with the minute particles of the oil, surrendering its heat f j 11'8COIl'ibining the molecules of the oil into a cracked product. Because of the minutedimensions of the individual particles and their rapid turbulent motion, the cracking process takes place very rapidly, the resultant cracked vapors and gases escaping through an exhaust pipe H at the end of the vessel.
A certain amount of steam is diverted through openings !2 into a jacket space I3 between the shells :2 and 3 where the hot steam helps to maintain the required temperature in the cracking chamber l4. Steam escapes from the chamber through apertures 15 in the,form of fine jets. These apertures are provided in depressions Hi, the apertured walls extending vin substantially radial direction so that the jets follow approximately the inner surface of the shell 3 a shown in Fig. 2. The innumerable steam jets form a blanket at the surface of the inner shell, preventing formation of coke and other hard deposits, and removing such deposits as may form from time to time. By this arrangement one of the greatest difiiculties in the operation of cracking equipment is eliminated, there being no interruption with my system on account of clogged pipes.
The minute particles of coke and solid products of condensation of cracked hydrocarbons, being unable to settle on the walls of the vessel, will remain suspended in the gases. To remove them, I provide an arrangement shown at the right in Fig. 1 and consisting of a spraying chamber H at the upper port on of the vessel in communication with a pipe l8 through which a suitable liquid is delivered, such as oil, water, etc. The inner wall I9 of the spraying chamber i provided with a large number of minute perforations 20 through which the liquid emerges in the form of fine jets 2|, forming a curtain at'the end of the vessel in front of exhaust pipe H. The perforations or holes are staggered in order more fully to cover the path of the gases so that all impurities and coke particles are washed down with the jets into a collector 22 at the lower side of the vessel. The contaminated liquid 23 is removed through the lower end of the collector by a su table pipe 24 into a filter (not shown) or other purifying agency for removing the solid particles and rendering the liquid suitable for further use.
The main vessel is shown of a cylindrical shape. although. of course, it can be made of any other suitable shape, preferably as a body of revolution to facilitate the whirling effect produced by the various jets. It should be also noted that the body may be placed in any convenient position, not necessarily horizontal, since no part of the cracking process proper depends on gravity, and the jets will be equally effective for any position of the vessel.
Because of rapid and thorough heat exchange in my device, no port on of my apparatus will require any excessive heating, and the cracking reaction will flow very satisfactorily with steam superheated to about 800-1400 F. and at pressllreS from about to about 50 psi.
My system has a particular advantage that t allows the use of h gh cracking temperature since there is no coke formation to interfere with the process. Moreover, the operative temperature and pressure can be easily and quickly changed to suit the particular cracking characteristics of the stock used.
It is understood that my method and means for cracking petroleum'oil may be further modified v without departing from the spirit of the invention, as set forth in the appended claims.
I claim as my invention:
1. An apparatus for cracking petroleum oil comprising a cylindrical vessel; a plurality of nozzles supported at spaced intervals along the cylindrical wall of the vessel and extending inwardly in tangential direction; the nozzles being adapted to admit oil into the vessel; a tube supported axially in the cylinder throughout its length; having a plurality of openings extending into the vessel, the tube being adapted to receive an elastic fluid; and means to exhaust the vaporous mixture of the oil with the elastic fluid at the end of the vessel.
2. An apparatus for cracking petroleum oil comprising a cylindrical vessel; a plurality of nozzles supported at spaced intervals along the cylindrical wall of the vessel and extending inwardly in tangential direction; the nozzles being adapted to admit oil into the vessel; 9. tube supported axially in the cylinder throughout its length; having a plurality of openings extending into the vessel, the tube being adapted to receive an elastic fluid; means to exhaust the vaporous mixture of the oil with theelastic fluid at the end of the vessel; and means to form a curtain of straight parallel streams of a liquid in front of the exhaust means.
3. An apparatus for cracking petroleum oil comprising a cylindrical vessel; a plurality of nozzles supported at spaced intervals along the cylindrical wall of the vessel and extending inwardly in tangential direction; the nozzles being adapted to admit oil into the vessel; a tube supported axially in the cylinder throughout its length; having a plurality of openings extending into the vessel, the tube-being adapted to receive an elastic fluid; means to exhaust the vaporous mixture of the oil with the elastic fluid at the end of the vessel; and a semicircular container in the upper portion of the vessel at the exhaust end having a plurality of perforations for admitting a liquid into the vessel in the form of parallel jets for washing the gaseous product before entering the exhaust opening.
4. An apparatus for cracking petroleum oil comprising a cylindrical vessel; a plurality of nozzles supported at spaced intervals along the cylindrical wall of the vessel and extending inwardly in tangential direction; the nozzles being adapted to admit oil into the vessel; a tube supported at the rear end of the vessel coaxially therewith and extending to the front end thereof, the front end of the tube being closed, the tube being adapted to receive elastic fluid through the rear end, the tube having a plurality of openings along its length for admitting the elastic fluid into the cylinder; and means to exhaust the va-' porous mixture of the oil with the elastic fluid.
5. A method of cracking petroleum oils, cons sting in forming a cylindrical rotating body in a confined space, the body comprising a mix ture of a minutely atomized oil with steam; causing the mixture to move in an axial direction toward one end of the confined space; and
. exhausting the mixture at the end of the confined HARALD E. LONNGREN.