US1715643A - Apparatus for treating hydrocarbons - Google Patents

Description

vJune 4, 1929. L. DE FLoREz APPARATUS FOR TREATING HYDROCARBONS original Filed J`u1y 8, 1919 Patented June 4, 1929'.

UNITED STATES PAT-ENT oFFlcE.

Luis ne nonna'or romrnnr, CONNECTICUT, Assi-@Non To 'run muxas comm.' I' i or NEW Yoan, N. Y., A oonronarroN or DELAWARE.

APPARATUS FOB TBEATING HYDROC'ABBONS.

Application led July 8, 1919, Serial No. 809,500. Renewed July 6, 1928.

The present invention relates to improvements in apparatus for cracking oils to produce low boiling hydrocarbons from similar material havin relatively high boiling points. One object of the present invention is to produce, in commercial quantities, a distillate of suitable characteristics to be used as fuel in internal combustion engines, in such a manner as to reduce the loss of valuable products commonly resulting in socalld cracking operations as heretofore practice Various methods of cracking or decomposing hydrocarbons by subjecting them to relatively high pressures and temperature, as heretofore generally practiced, have frequently involved material losses in the form of undesirable products produced in too great proportion during the recovery of valuable products. These undesirable products include gas, residue, or heavy boiling material and coke. It is known in connection with socallecl cracking operations, that a certain proportion of material will go to form a gaseous product which retains its identity as a gas at normal temperature and pressure, while the balance will produce liquid products of low boiling and high boiling properties. The proportion in which these products are formed is a relatively constant one, that is to say, with a given method of treatment of a given raw material and assuming no defects in the apparatus, gas and liquid prod. ucts will be formed in virtually uniform proportion. It has been observed that, if during the operation of the cracking process, a portion of the gas resulting from the cracking of a given amount of raw material be withdrawn from the system, a new formation or readj ustment of the relative amounts of gas and liquids will take place and it will be found that an additional amount of gaseous products will be formed, thus increasin the gaseous product at the expense of t e liquid product. To avoid this loss of liquid product where it is desired to withdraw gas for certain useful purposes, I propose to inject a portion of the gas normally formed by operation of the process, or otherwise. provided, into the system along with the oil which is under treatment, so that a balance "between the gaseous compounds and other products will be established to' such an extent' as to minimize the formation of new gas. It

is contemplated that the formation of less gas from ca ch increment of material treated wllltend to increase the proportion of desired liquid products.

One of the chief practicalA difficulties in cracking oils results from the fact that the o1l wlll deposit a certain amount of carbon durlng the process. In certain types of apparatus, the carbon deposit materially interferes with the proper functioning of the apparatus. When cracking in a still or large contalner, the deposition of carbon is commonly allowed to take place on the sides and may conveniently be removed by hand at suitable intervals. However, it will be evident that when the oil cracking rocess takes place in tubes, the deposition o carbon is a morev serious matter and unless controlled effectively, it prevents the uniform flow of oil through the apparatus, thus making it necessary to cease operations and to clean the tubes. This rocedure obviously interferes with economlcal and effective operation of the plant and no tubular apparatus is really a commercial success unless suitable means are provided for readily removing the carbon in operation, or for positively preventing its deposition at critical points. Mechanical means commonly used for removing carbon deposits have not been found practicable since the working parts necessarily operate under unfavorable conditions of temperature. I propose t9 improve tubular processes in partby preventing deposition of carbon in the tubes 1n any practical manner such asty increasing the velocity of the Huid in e tubes, said velocity being controlled by suitable means, as by temperature and variation in the cross sectional area of tube opening, or by either one independently of the other. In practice, satisfactory variation in tube section may be accomplished by the use of pipes of varying standard sizes.Y In addition to this particular means of increasing the speed of velocity of the liquid in the tubes, further increase may be effected by increasing the volume of the fluid by raising its temperature. The effect of carrying the fluid through the pipes at high velocity is twofold. First, it causes a turbulent flow which insures good heat transfer due to 'extensive contact of the fluid with the sides of the pipe and therefore uniform heating of the material passing through. Secondly, high speed of ow entraine-carbon about` tov be deposited along withtheilnidin vapor form to a point where it .may bef'desirable to drop the carbon le such as a change in by any Suits.

- direction of How or a partial cooling of the uuid, or expansion.

One embodiment of my invention vis illustratod in .part diagrammatically in the drawings acoompan ingthe present specilication, and -in whic 2-2of AFigure 1,

2o drocarbon to be ytreated may be drawn from acome the 30 structed in such duced be provided.

being indicated Figure 3, a detail view partly -in vertical section showing connection between-,the oil va or conduit and the gas conduit.

eferring to said drawings, the liquid hysuitable container, such as a running tank 1,

b means of a pump 2 arranged to force theA oil into an expansion chamber or riser 3. The expansion chamber acts as a cushion to overefect of pulsations of the charging pump 2 and to insure the -uniform deliveryl of oil to the converter. From this expansion reason of the pump pressure, passes through a filter 4 cona manner as to remove from said hydrocarbon all sediment and solid materials. The hydrocarbon thus purified iows through a meter 5 either at the pressure substantially as produced by pump 2, or at a reressure eiect'ed by means of a regulating va ve 6 interposed between said meter and the iilter 4. In case it is desired to reduce the chamber, and by the hydrocarbon pressure afterpassage of the hydrocarbon' meter, a regulating valve 7 may After passing through the ineter, the hydrocarbon may beheated'to a predetermined temperature by any suitable means, here shown as a coil 8 enclosed in a steam chest 9.

The apparatus may also include a suitable furnace for heating the hydrocarbon from atmospheric temperature to a suitable oil cracking temperature, such as approximately 610 centigrade,a preferred form of said furnace diagrammatically in the drawings and comprising substantially a combustion chamber and a heating chamber communicating therewith and having a bale 11 interposed in the path of the products of combustionwvhich may be permitted -to escape through a flue 12 and thence to the atmosphere through a chimney 13, if desired. The hydrocarbon coming from the steam heated coil 8 through a feed pipe 10 is carried through the heating chamber of the :furnace through a suitable conduit 44 comprising a series of bends of pipe depending into the heating chamber from a suitable supporting element or top plate -14. The bends 'of pipe comprising through the the conduit supported by the top plate 14, arev connected in series and are of such dimensions discharges the hydrocarbon into conduitp44 at a relatively cool portion of the heating chamber and the temperature o the hydrocarbon `is gradually raised as it passes through convolu- I tions of the conduit depending in increasingly hotter portions of the heating chamber. -A suitable arrangement of4 pipes constituting the conduit for conveyinc` the hydrocarbon through the heating chambber may include a plurality of two inch pipes receiving h drocarbon directly from the feed pipe 10. `rom the two inch pipes, the hydrocarbon'ma be led through a plurality of One and one-'half inch pipes and thence into a plurality of one inch pipes, said one inch pipes being arranged in that portion of the heating. chamber in which the 'maximum or predetermined crackinor temperature is available.

t is contemplated that the hydrocarbon will be entirely vaporized, under normal conditions of operationin a portion of the conduit located in a cooler portion of the heating chamber than that in which the cracking takes place. The vapor thus formed will then pass into pipes located in a relatively hotter portion of the chamber where cracking will be eil'ected, the resulting product being then carried to an expansion chamber 15 in which it is intended that the deposition of carbon and other residualproducts shall take place, such as materials having boiling points ranging from 300 centigrade and upwards, if desired. The expansion chamber 15 may include a receptacle 16 havin@ a baille 17 arranged opposite the opening of expansion chamber 15, said receptacle and baille being adapted to eii'ect a further deposition Vof carbon which may be readily removed from said receptacle through a door 1'8 hinged to the bottom of said receptacle. A condensing chamber 19 encloses a condensing coil 20 carrying the vaporized and cracked hydrocarbon, said coil being arranged to discharge the products of condensation into a receptacle or tank 21 from which the liquid deposit may be withdrawn through a suitable pipe 22 to 'a storage tank 23, said pipe 22 being*j provided with a valve 24. A door 25 may e secured to the bottom of tank 21 for the purpose of removing sedimentary L deposits too heavy to iiow through the pipe 22.,`

and conducted through said conduit to the combustion chamber of the heating umt where the gas may be utilized to produce the heat re uired in the operation of vaporization an cracking the hydrocarbon in conduit 44.

In order. to maintain a predeterminedcracking temperature in said conduit and in the heating chamber of the heating unit, sultable temperature controlling means may be provided including a pyrometer 28 of any suitable construction preferably arranged in a portion of 'the conduit which carries the cracked hydrocarbon. This pyrometer may be operatively connected with an indicator dial 29 arranged in such position that the operator may readily perceive any deviation from the predetermined` temperature and control said temperature by increasing or diminishing the supply of fuel in the combustion chamber. For this purpose a hand operated valve 30 may be provided. Obviously, the adjustment of fuel supply may be made automatic by suitable controlling mechanism interposed between a fuel supply controlling valve andthe pyrometer 28.

Another portion of the gas formed in tank 21 may be drawn therefrom through 'a pipe 31 and into a compressor 32 from which it is forced through a condenser 33 and into a reservoir 34. Any liquid or distillate deposited in this reservoir by reason of the further cooling of the gas may be Withdrawn therefrom through a pipe 35 controlled by a valve 36 into the storage tank 23.

Where it is desired to utilize the gas pumped into tank 34 as described by intro- 4 ducing it into the hydrocarbon at any desired point in the cracking operation, a feed line 37 may be arranged to connect said tank with the liquid hydrocarbon feed pipe 10, or with the conduit 44, or with the expansion chamber 15, valves 38, 39 and 40 being provided to control the flow of gas into the feed pipe 10, the conduit 44, and the expansion chamber 15, respectively, it being contemplated that the pressure at which the gas is admitted tothese various parts may be in part controlled through manipulation of said valves. A

Where it is desired to heat the gas drawn from tank 34, before introducing 1t into the portions hereinabove referred to, the gas may be deflected into a pipe 41 through a valve 42, under which conditions the valves 38, 39 and 40 may be either partially or entirely closed,

as circumstances require. When valve 42 is open, gas may be fed through pipe 41 into a coil 43 located in the heating chamber of/the heating unit and may be admitted into the conduit 44 through a valve 45, or into the expansion chamber 15 through a valve 46. If it is desired to introduce the heated gas into the relatively cool liquid hydrocarbon in the feed pipe 10, a pipe line 47 may be arranged to connect with said feed pipe 10, said line 47 being conveniently controlled by a valve 48.

Under some conditions of use, it is cpntemplated that a supply of any suitable inactive gas may be maintained in a conveniently arranged receptacle 49 from which itA may be pumped into the pipe line 37 by means of a pump 50. A valve 51 interposed in said pipe 37 may be utilized to prevent the forcing of gas from the tank 49 into tank 34.

1n operation, it has been found that a suitable primary operating pressure on the liquid hydrocarbon is approximately 250 pounds, said pressure being developed in pump 2. This primary pressure may be stepped down to provide a suitable feed pressure either by means of the regulating valve 6 or the regulating valve 7 arranged respectivel at either side of the meter 5, it being desirab e to regulate the ow of hydrocarbon so that it may be constant. The initial feed pressure of 125 pounds is substantially maintained throughout the system until the hydrocarbon is vaporized after which the pressure will be reduced until the hydrocarbon reaches the distillate receiving tank 21 in which a pressure of approximately 15 pounds may be maintained. To force the gas from tank 34, or from tank 49, into the circulating system at the points hereinabove mentioned, or others, it Will be found that a pressure approximately equal to or slightly greater than that existing at the particular point of entry may be used.

In practicing the method hereinabove outlined in connection with the apparatus described, it will be understood that one of the objects' of m invention is accomplished by introducing into the hydrocarbon a suitable inactive gas, preferably one which when mixed with the hydrocarbon will not promote combustion, such as a hydrocarbon gas which will combine with the oil under treatment, thus providing such an excess of gas in the cracked and vaporized hydrocarbon that a relatively smaller proportion of gas formation will be found to have taken place under condensation of said vaporized and cracked hydrocarbon than is ordinarily found Where the excess of gas is not so introduced. Thus, by restricting the amount of gas product, I proportionately increase the amount of the desired liquid product thereby effecting a material economy in the operation of a plant of the character described. I

A further object of my invention isy attained in the increasing of the velocity of the hydrocarbon passing through conduit 44 in the heating chamber of the heating unit. By gradually reducing the cross sectional area of the opening of the conduit, I effect a corresponding increase in the speed of the hydrocarbon vapor as it passes through said conduit, said speed being so great that the i tendency of (particles of carbon to deposit is overcome an the carbon iscarr'ied along into the expansion chamberl and-the expansion receptacle 16 where itmay be deposited Without interfering with thev continuous operation "of the plant.. The'speed of -the vaporized hydrocarbon is further increased in the relatively constricted portions'ofthe conduit -by the increased temperature maintained in that portion of the heating chamber in which the more constrcted' portions of the conduit 44: are arranged, the combinationA of addi tional heat and constrictedfv-opening operat ing to produce such a speed that carbon will not be deposited in the conduit. A

I claim as my invention:

1. Vaporizing apparatus for hydrocarbons comprising a4 source of heat, a heating chamber having vaporizing members depending therein, said membersin 'the' hotter zone of the heating chamber 'having a re duced cross sectional area as compared with the cross sectionall area ofA the de ending members in the. cooler zone of the eating chamber, and means for introducing the hydro'carbons to the vaporizlng members of larger area for passage thence to the vaporzing members of reducedl area. '2. Vaporizing apparatus for hydrocar- ,bonscomprising a source of heat, a heating LIS DE FLOREZ.Y

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