US1220504A - Apparatus for dehydrating hydrocarbon-oils. - Google Patents

Description

. E. I. DYER.

APPARATUS FOR DEHYDRATING HYDROCARBON OILS.

APPLICATION FILED MAR. 5. 191a.

1,2g0,5@%n Patented Mar. 27, 1917.

2 SHEETS-SHEET l- E. I. DYER. APPARATUS FOR DEHYDRATING HYDROCARBON OILS.

APPLICATION FILED MAR. 5. l9l3.

' ATTORNEY Patented Mar. 27, 1917.

2 SHEETS-SHEET 2.

ra amas PATENT carton ERNEST i. lover, or oa xmnn, camronma.

arrarm'rus roa DEHYDRATING HYDROCARBON-OILS.

To all whomrz't mayconoern: i Be it known that I, ERNEST I. DYER, a citizen of the United States, residing at Oakland, in the county of Alamedatand State of California, have invented certain new and useful Improvements in Apparatus for Dehydrating Hydrocarbon-Oils, of which the following is a specification.-

While the hereinafter described apparatus is applicable to the treatment of hydrocarbon oils generally, the same is more particularly adapted to those Californian petroleu-ms which contain considerable quantities of water in an emulsified form, which cannot be readily and economically separated from the oil by settling, moderate heating, blowin with air, or by the application of other wel known means usually resorted to for such purpose. These oils are usually dehydrated by evaporation of the water by raising the mixture of oil and water to such a temperature at sensibly'atmospheric pressureas will cause ebullition, driving ofi' the water and the more volatile constituents of the oil simultaneously, in the form of a mixed vapor which is subsequently condensed and the liquid components separated by allowing the water to settle.

The objects of the present invention are to increase the yield of the lighter distillates over that obtained by the means at present resorted to for dehydrating and refining the hydrocarbon oils without danger of breaking down the lighter fractions, 'or formation of unsaturated hydrocarbons or other bodies of an objectionable character to such an extent as to involve more expensive chemical after treatment; to permit the utilization of the latent heat of :evaporation of the mixed vapors produced on heating the oil under treatment, in such a manner that they shall themselves assist in doing the W013]; of evaporation; to remove any des red vproportion of the emulsified water in the crude oil,

and provide against the production of an emulsion of water and light distillatesgto',

successfully treat such petroleums as, when subjected to ordinary cracking processes to;

increase the yield of light distillates, yield an'excessive amount of so-called fixed gases and unsaturated hydrocarbons, resulting in no material gain, through breaking down of Specification of Letters Patent.

Application filed March 5, 1913. Serial No. 752,092. A

Patented Mar.27,1l91'?.

the molecules of the lighterhydrocarbons as well as those of the heavier; to provide against subjecting the lighter and more valuable distillates to any cracking effect, confining such effect to the less valuableconstituents of the crude oil; to provide for a simpler, less expensive, and more economical working of the-hydrocarbon oils than is at present effected in connection with the dehydration and refining of such oils.

Qwing to the high latent heat of evaporation of water as compared with the latent heat of evaporation ofthe constituents of petroleum, all of the usual evaporative systems require excessive expenditure of fuel; and, owing to the v-iolen't'ebullition of mix tures of oil and water when certain more or less definite temperatures are reached, under ordinary conditions of operation violent priming of the stills is experienced, resultthe vapor pipe, finally settling to the bottom of the-receiving tank usually employed and being usually thrown away, under the assumption that is not only a material with- -o .ut value, but that in addition, being composed of sand and mineral matter, it needs to be removed from the oil so that the final residuum may meet the requirements of customers who use it as a fuel. under my observation for some months, this {emulsion (which was thrown away) was actually produced by the plant at the rate of 1000 to 1500 barrels per day. Yet it contained, by analysis, material which was demonstrated to have a market value sufficient to bring man income of several hundred dollars per day, which loss is saved by'the use of the hereinafter described apparatus for treating the hydrocarbon oils.

In the use of my apparatus, the oil to be treated is subjected in a vessel closed except In one plant for its inlet and outlet, to a temperature which at normal pressure will drive off the lighter and more tender distillates without injury, after which they are removed from possible harm in further stages of the process, where higher pressures and temperatures are used. The oil being thus treated is immediately and Without cooling, passed to a second similar vessel where it is subjected to higher temperature and such pressures above the normal atmospheric pressure as experience indicates to be suitable. In this second vessel, conditions of temperature and pressure may be such as to encourage a moderate decomposition of some of the hydrocarbons still left in the oil.

The oil is introduced into both vessels and caused to circulate in a circuitous path in such a way as to cause its temperature to be raised gradually, while its surface, which partakes of practically the same temperature as that of the body of the oil at any given point, is in contact with the vapor in the upper part of the vessel, this vapor being normally of a temperature somewhat higher than that of the entering oil and somewhat lower than that of the outgoing oil. The contact of the vapor in the vessel with the relatively cool oil surface results in a certain amount of condensation of the vapor on the surface of the oil, the condensate being carried by the motion of the oil into regions of highertemperature where reevaporation takes place, producing results analogous to those given by dephlegmators, or column stills. This action tends to promote sharper fractionation and a yield of lighter distillate greater than that obtained by ordinary refining processes without dephlegmators.

By means of the circuitous travel of the oil in the vessels mentioned, the incoming oil and the outgoing oil are kept widely separated, and of as different composition as can be possible when confined in the same vessel. In this way. the outgoing oil carries off fewer of the low-boilingpoint fractions than it would if the circulation were of a fortuitous character.

To comprehend the invention reference should be had to the accompanying sheets of drawings, wherein Figure 1 is a diagrammatic view of a side elevation of a plant adapted to carry out the process, employing steam as the primary heating medium, and an emulsified oil as raw material to be dehydrated and par tially refined. said view disclosing one of the heating vessels, partly broken away, and the companion vessel, the interchanger and the condenser in vertical section.

Fig. 2 is an irregular horizontal sectional plan view of one of the heating vessels for the flowing oil.

Fig. 3 is a detail view of one of the vertical baflie plates removed from one of the heating vessels.

Fig. 4 is an enlarged detail sectional View of one of the headers taken on the line 44 of Fig. 2. x

Fig. 5 is a detail view, on an enlarged scale, of one of the traps, and

Fig, 6 is an enlarged detail elevation of one of the headers.

In the drawings, the letters A and B are used to designate what will be termed heating vessels or cylinders of similar construction, the upper one of which is shown in vertical section. Each vessel is provided adjacent to its bottom with a nest of horizontally disposed circulating tubes or pipes through which the heating mediumsteam, vapor, or any other substance, may pass and circulate.

These vessels may also be heated externally by any other suitable means, butas one or both may be operated under pressure, I prefer the method shown, for the sake of safety; but do not limit myself to it alone. The heating tubes A of the vessel A and the tubes B of the vessel B are arranged as shown in the horizontal section in Fig. 2, in this instance being in the form of U-tubes, since this is a convenient form for allowing .for expansion and contraction,

although I do not confine myself to it exclusively, and are connected respectively to the headers C and C, the inlet of the heating agent being indicated at ti and the outletat d. Tubes to any desired extent of heating surface are introduced and divided by a system of vertical longitudinal baflies D, and vertical cross baffles D, in such a way that the oil which is caused to enter at the opening a, (see plan-Fig. 2 of the drawings), shall be constrained to follow a tortuous path, as indicated by arrows, in a direction in general parallel to the tubes, up to the point of exit I). The cross baffles D are arranged with openings a9, through which the tubes pass and in which they are supported. These openings are of sufficient size to permit of a reasonably free passage of the oil circulating within the heating vessels Or the horizontal tubes therein. All bafiies within either heating vessel are carried up to about the mid-section of the vessel or to such a height as will prevent the foam which forms on the surface of the oil from short-circuiting to the outlet without having been compelled to either traverse the same course as the oil itself or else be dissipated before reaching the outlet. The oil level is "maintained so as just to cover the tubes, so that the oil shall be present in the vessel in relatively small quantities, and its level shall be so low as to preventits reaching the vapor outletin case of violent frothing. In this way the oil is divided up into very small masses and brought intithrough the conduits n, E.

mately into contact with the heated surfaces of the tubes about which the oil circulates, and as it is further caused to flow continuously in a direction parallel to that of the tubes and counter to the direction of flow of the heating medium, conditions for rapid and efficient heat transfer and free liberation of vapor are provided. Under each set of U-tubes I may introduce a perforated agitating pipe f, through which steam is ejected into the vessels to promote still more eflicient heat transfer by agitating the oil contained. therein, and also to assist in the liberation of the vapors and to keep heating surfaces free from scale-forming elements, the steam'being conveyed from a suitable source of supply to said agitating pipes The vessels A and B are "proportioned so as to have large liberating surface and ample liberating space above the surface of the liquid admitted therein, and as the bills also introduced gradually and in relatively small quantities it is not all in the same "state of ebullition at any given instant, withthe result that violent. priming is prevented. Further protection is given against violent priming by causing part of the work of evaporation to be done in each vessel, and

by the fact that evaporation takes place under pressure in the hotter vessel, it being 2 well known that evaporation of liquid under pressure can be accomplished more rapidly without priming than when pressure is, absent. e

As stated, the vessel B is exactly similar in construction to that of vessel A, but the heating medium in itstubes B consists of the mixed vapor from the vessel A under pressure. The vapor from vessel A is entirely condensed in the tubes of vessel B, vessel A being operated under pressure in order that there shall be sufficient temperature head in vessel B'to permit of complete transfer of the latent heat of the vapor from vessel Ato the liquid contents of vessel B. By this means, the heating medium introduced in the tubes A and vessel A, in this case steam, not only evaporates a quantity of liquid in the said vessel A proportional to the amount of steam supplied from some out side source, but by means .of the arrange- V ment described, eva'perates almost an equal additional amountinthevessel B. So that with the arrangement shown, neglecting loss of heat by radiation, etc, the original heating medium does, roughly, about twice the work it would do under ordinary conditions. This results inia great saving of fuel. I wish to lay particular stress on the fact that with an 011 containing a considerable quantity of water in emulsion complete utilization of the latent heat in the vapors" from A cannot be obtained unless the interior of vessel A is maintained at a higher pressure than the interior-of vessel B, a higher pressure being maintained in the vessel A by maintaining a higher temperature therein, the means for this purpose, in the present instance, being steam introduced from an out side source into the heating coils A of the vessel A. Operation under varying stages of pressure on this character of oil is therefore necessary to effect high heat efficiency and low fuel cost.

In the particular construction illustrated in the drawing, the hydrocarbon, to be treated, first enters the apparatus through apipe L leading into'an interchanger K from which it passes through the outlet pipe M, the inlet connection E of the vessel B,

and into said vessel B, in which it is partially distilled by heat derived from the vaporsfrom vessel A said vapors from the supply of heat from outside sources.

Pressure is maintained in vessel A by causing the vapors which condense in the tubes B of vessel B to discharge "through the piping B connecting with an automatic trap F of any approved type or other suitable means which allows only liquid to pass therethrough.

The particular construction of trap shown comprises a vessel provided with an inlet R and an outlet pipe R, the inlet R being connected with the pipe connection B, and the outlet R with the pipe J. In the interior of the vessel is a pot P pivotally mounted as at A". adapted to cooperate with a valve seat C said valve being carried at the upper end of a rod B, which is pivoted at its lower end to the pot B The operation of the trap is as follows: Mixed liquid and vapor en ter through the inlet R, the liquid causing the pot in the interior to float keeping the valve in closed position until such time as the accumulation of liquid in the trap has become so great that it overflows into the interior of the pot. When this occurs, the pot fills and sinks, the valve C being opened with the downward movement of the pot P and the pressure of the steam or vapor, as the case'may be, forces. the contents of the potout through the outlet R. With the removal of the liquid from the pot the same is lightened and the pot floats, again closing the valve. By a proper relative proportioning of' the heating surfaces in the two vessels, the relative amounts of evaporation in the said vessels may be distributed as desired, so that any bodies contained in C designates a valve Ill@ the raw crude oil which'might be injured by the pressure of temperatures obtaining in vessel A will be removed in vessel B. In this arrangement of flow, the relatively light crude oil is first subjected to the lowest temperature and ressure of the process and the relatively eavy partially dried oil is subjected to the highest pressure and temperature of the process, not only for the reason that the light fractions are more liable to damage by the effect of relatively high pressure and temperature than the heavy portions, but for the additional reason that the heavy portions normally boiling at higher temperature than the light portions require the application of a higher temperature heating medium to extract their less volatile constituents. J

While this direction of flow is the correct one for relatively light oils containing water in an-emulsified form, it is not necessarily the only correct one for heavy emulsified oils containing little volatile matter, and I do not wish to restrict myself to this direction of flow, choosing on occasion with suit able character of oil to reverse the direction.

This arrangement may be extended indefinitely and the vapor discharged from the vessel B may be used to heat a third vessel, and so on, each succeeding vessel being operated at lower pressure and temperature than the vessel immediately preceding. In the present case, the vapor generated in vessel B is withdrawn through the perforated pipe G extended therein and" conveyed thereby to a condenser G", Fig. 1 of the drawings, which condenser may be of ordinary construction and which may use water or oil as a cooling medium, according to circumstances The vapor passing through the pipe G discharges eventually into a header to the condenser G. In the drawing it is shown as first passing through a dephlegmator H which is interposed in the pipe connection- G, although the use of the dephle mator is not essential except where sharp ractionation is required. The header G is divided by a horizontal wall 9 into an upper chamber g and a lower chamber k, and the vapor discharged into the upper chamber 9" escapes therefrom through the U-shaped tubes H located within the condenser and connected with the said chambers g and h, and flows through the said tubes H- until finally discharged as a condensate from said tubes into the lower chamber h, from which chamber the distillate and water discharge through the outlet pipe h and are run to suitable tanks (not shown) where the water is drawn ofl. The water or oil used as a cooling medium enters the a condenser through the supply pipe H, circulates within the condenser surrounding the tubes H 2 and escapestherefrom through the outlet pipe I, the flow of the cooling mecuum being directed by the horizontal baflie J within the condenser. The operation of dephlegmators in connectionwith the treatment of the hydrocarbon oils being well known and understood, a description of the working thereof and the advantages flowing therefrom is needless in the resent case.

The heavy distlllates flowing from the interior of the heating tubes of the vessel B into the interior of 'the header C pass through the outlet d through the pipe B to the trap F.. From the trap F, by closing the valve K and opening the valve y, the distillates may be discharged into the condenser G through the pipe connection J, the latter connecting at its upper end with the pipe G; or by closing the valve j and opening the valve K the distillates may be led ofl through a pipe connection to any other point desired.

Where fuel is relatively expensive, instead of condensing the vapors from the vessel B, by means of Water or crude oil, I may use them or any of the other vapors for redistilling the crude naphtha or distillate-produced by the plant, thus delivering gasolene or similar merchantable refined materials by continuous operation direct from the crude oil. I may also use a part of these vapors where under pressure, for the generation of power in pumps, engines, or auxiliary apparatus of the plant; and where exhaust steam is available from engines, pumps, or other steam using appliances, I may also introduce it at suitable points into-the heating tubes of the vessels described, there utilizing it for heating purposes; or I may use it in the agitating ipes.

The vapors w ich condense in the tubes of the various vessels may be run to ordinary coolers, or may be caused to give up their heat at any point where temperature conditions render an interchange of heat possible or desirable. Where steam is used as heating medium in the first vessel A, I return the drips by means of a pipe E to a trap Eor suitable automatic pump and re ceiver, direct to the steam boilers, not shown; The trap E, in the present instance, is of the same construction as the trap F. A supply conduit d for the heating medium connects with theinlet d of the header 0 of the vessel.

After the oil leaves vessel A, I customarily pass it through the interchanger K, where it assists in preheating the incoming crude oil for the plant.

In this case, the crude oil is forced into the interchanger through the supply pipe L and circulating around and flowing over the heated surfaces of the nest of horizontally disposed U-shaped pipes L receives an initial heating, leaving the interchanger through the outlet pipe M, which connects 13o the lighter portions as may pass ofi as vapor during the preliminary heating escape through the outlet M of the interchanger and are conveyed to a suitable place of deposit. The heated oil or residuum from the vessel A discharges through the outlet S into a pipe S leading to the upper chamber Z of the header n of the interchanger, escaping therefrom through the upper run of the pipes L and circulating therethrough discharges into the lower chamber Z of the said header, finally escaping through the residuum outlet N. The flow of this hot oil through the tubes L heats the same to such an extent as to givean initial heating of the infiowing crude oil and by so doing permits all heat units to be thoroughly utilized, the

baffle on within the interchange! K causing the inflowing'crude oil to flow in an opposite direction to the fiow of the heated oil from the vessel A.

The utilization of the interchanger with many oils will perform part of the work of evaporation, and under certain conditions may be employed for redistilling the distillates produced by the various vessels.

The apparatus herein described has been subjected to the practical test of dehydration and refining hydrocarbon oils for commercial use and on a large scale in connection with the oils obtained from the fields of Santa Barbara county, California. The oil used during this period contained 15% to 30% of water in an emulsified form of a particularly refractory character. The plant was installed with the expectation that if it should prove successful it would re lace the existing plant, which distilled ofi t e water from the crude oil together with the light hydrocarbons by means of steam stills operating under atmospheric pressure. The old plant and the new plant were operated simultaneously on exactly similar oil, and the present apparatus proved successful and.

created a material gainover the old plant then in use. The described apparatus may be installed and operated in two or three stages of pressure and temperature, but so far it has been operated in two stages. During this time it has successfully handled severalmillions of barrels of oil, removing over a million barrels of water from the emulsion in the oil using about one-third of the fuel required by the old plant and similar evaporative plants, and its production of distillate from the same quantity and quality of oil as that used by the old plant has been greater, a series of laboratory tests showing theyield of distillate from the plant to be considerably greater than that obtained in the laboratory by ordinary laboratory methods. Comparison of the yield of distillate produced by the old plant above referred to with the yield produced by the plant incontained, the proportion of low boiling point fractions, etc.; it is possible under certain conditions to dispense entirely with water as a cooling medium-a feature of extremevalue in many oil fields located in arid regions.

Having thus described my invention what I claim as new and desire to protect by Letters Patent is 1. An apparatus for treating hydrocarbon oils for the described purpose, the same comprising a plurality of closed vessels, means for each of said vessels for causing the oil to flow in relatively small streams in a tortuous path therethrough, said means including a plurality of closely associated vertical longitudinal bafies in the vessel, a series of heat circulating tubes in each vessel, the circulatingtubes being arranged so that some of the tubes extend between adjacent baffles, means for delivering oil for treatment into one of said vessels, devices for forcing a heating medium from an outside source of supply through the heat circulating tubes of the companion vessel, means for conveying the vapors generated from the oil in said vessel into and through the heat circulating tubes of the first mentioned vessel'for the heating ofthe oil contained therein, devices for leading the oil from said vessel and forcing the same into and through the second vessel, and means for removing the vapors flowing from the use from the first mentioned vessel to a suitable place of deposit a 2. An apparatus for treating hydrocarbon oils for the described purpose, the same comprising a plurality of closed vessels, a series of heat circulating tubes arranged in each of said vessels, means for each of said vessels for causing the oil to flow in relatively small streams in a tortuous path therethrough, said means including a plurality of vertical longitudinal baffles within the vessel, and a plurality of transverse vertical bafies, means for delivering oil for treatment into one of said vessels,devices for forcing a heating medium from an outside source of supply through the heat circulating tubes of the companion vessel, means for conveying the vapors generated from the oil in said vessel into .and through the heat circulating tubes of the first mentioned vessel for the heating of the oil contained thereinydevices for leading the oil from said'vessel and forcin the vessel, and means for removing the vapors from the first mentioned vessel to a suitable place of deposit. 7

3. An apparatus for treating hydrocarbon oils for'the described purpose, the same comprising a plurality of closed vessels, a series of heat circulating tubes in each of said vessels, means for each ofsaid vessels for causing oil delivered thereto to flow in relatively small streams in a tortuous path therethrough, said last mentioned means including a plurality of closely associated vertical longitudinal baflles within the vessels extending upwardly from the bottom thereof to a 1 point substantially midway of the height of the vessels, and transverse vertical baflies provided with openings therethrough located below the tops of the longitudinal baifles, means for delivering oil for treatment into one of said vessels, means for supplying a heating medium to the heat circulating tubes of the companion vessel, means for conveying the vapors generated from the oil in said vessel into and through the heat circulating tubes of the first mentioned vessel for the heating of the oil contained therein, devices for leading the oil from said vessel and forcing the same into and through the second mentioned vessel, and means for removing the vapors of the first mentioned vessel to a suitable place of deposit.

4. An apparatus for treating hydrocarbon oils for the described purpose, the same comprising a plurality of closed vessels, and

means for each of said vessels for causing the oil delivered thereto to flow in relatively small streams in a tortuous path therethrough, said means including a plurality of closely associated vertical longitudinal bafflcs in the vessels, and transverse baflles provided with openings forming passages through the same for oil, a series of heat circulating tubes in each of said vessels, said heat circulating tubes being arranged so that some of the tubes extend between adjacent longitudinal battles and through the openings in the transverse baffles, said tubes being of a size in cross section less than the cross sectional area of the openings, means for supplying a heatingmedium to the heat circulating tubes of the companion vessel, means for conveying the vapors generated from the oil in said vessel into and through the heat circulating tubes of the first mentioned vessel for the heating of the oil contained therein, devices for leading the oil from said vessel and forcing the same into and through the second mentioned vessel, and means for removing the vapors from the first mentioned vessel to a suitable place of deposit.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ERNEST I. DYER.

, Witnesses:

N. A. AcKER, D. B. RICHARDS.

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