US2743915A - Equipment for use in treating oil by steam stripping - Google Patents

Description

May 1; 1956 B. DE H. MILLER ETAL EQUIPMENT vFOR USE 1N TREATING oIL- ABY STM STRIPPING Filed June 15. 1952 I @Sheets-Sheet l` Filed Junels.' 1952 May 1,*1956 3. DE H. MILLER ETAL 2,743,915

EQUIPMENT FOR USE 1N TREATENG OILEBY STEAM STEIPPING 4 Sheets-'Sheet 2Y May 1, 1956 l B. D H, M lLLl-:R ErAx. 2743,915

EQUIPMENT FOR USE IN TREATING OIL BY STEAM STRIPPING Filed June 15, 1952 4 Sheets-Sheet 3 A TAIVE YS Malyv 1, 1956 B. DE H. MILLER ErAL vEQUIPMENT FOR USE 1N TREATING OIL BY'STEAM STRIPPING Filed June 1s, 1952 4 sheets-sheet 4 /f/vE/vraRs MMA WW MNM ArrdR/YEYS EQUIPMENT FOR USE IN TREATING OIL BY STEAM STRIPPING yBruce De Haven Miller and Charles E. McMichael, Louisville, Ky., assignors, by mesne assignments, to National Cylinder Gas Company, Chicago, Ill., a corporation of Delaware Application June 13, 1952, Serial No. 293,461

3 Claims. (Cl. 261 121) This invention relates to equipment for use in treating oil by steam stripping. The invention is particularly concerned with improvements in the splash plate type of equipment for this general purpose, i. e., the type of equipment in which the oil to be treated is projected in space against a splash or splatter plate by means of the stripping steam, so as to splatter the oil or break it up to increase surface area exposure to the stripping steam and thereby enhance the stripping action of the steam.

Briefly described, such an oil treatment equipment includes a receptacle or tray having bottom and side walls and adapted to receive oil up to a level only partially lling the tray. The splash plate is arranged toward the top of the tray well above the level of the oil therein. The splash plate covers the central region of the oil in the tray but has its edges terminated short of the side walls, to provide for exit of the stripping steam and 4the vapors or other constituents stripped from the oil by the steam and carried therewith. A steam inlet, usually comprising a perforated steam inlet pipe is disposed in the body of the oil well below the surface thereof. The operation is ordinarily carried out under high vacuum.

Introduction of the stripping steam into the body of the oil well below the surface causes the oil to be projected or splashed upwardly against the splash plate. In this operation there is a tendency for masses of the oil to be raised from the body in the tray upwardly along the side walls of the tray and into the steam exit passage between the edge of the splash plate and the side walls of the tray. This action sometimes tends to carry oil out of the tray through the steam exit passage.

One of the primary objects of the present invention is to prevent the oil from surging up the side Walls of the tray and into the steam exit passage around the edges of the splash plate. This is accomplished by the employment of a deilector projecting inwardly from the side walls of the tray at an elevation well below the splash plate and preferably below the normal level of the oil in the tray. The deector projects from the side walls of the tray only for a fraction of the total width of the tray, so as to leave a large central opening through which the oil may be projected upwardly against the splash plate.

According to the foregoing, the deector substantially eliminates surges of the oil upwardly at the side wallsV and thereby substantially eliminates danger of masses of the oil being projected into the steam exit passage around the edges of the splash plate.

Other objects and features of the invention will appear more fully hereinafter following a description of a preferred embodiment of the invention. In considering the embodiment illustrated in the drawings, it is here rst mentioned that the steam stripping equipment of the present invention is of general applicability to oil or even other liquid treatments requiring a high degree of efficiency of steam stripping. In connection with the use of the expression stripping steam herein, it is to be understood that any sparging operation is contemplated, such las stripping of some constituent from the oil or the-re.-

moval of air therefrom, or the introduction of steam as an aid to distillation or merely for the purpose of agitating the body of oil. As illustrativeV of a typical use of the equipment, reference is made to a plant for effecting de-r odorization of vegetable oils and the invention is illustrated in the accompanying drawings as applied to that particular use.

In the drawings: Figure l is a somewhat diagrammatic or outline view of the major components of an oil treatment plant such'A as employed for the deodorization of vegetable oils.

Figure 2 is an enlarged vertical sectional view through a portion of the oil treatment column of Figure l, showing the application of the equipment of the present invention in such a column. Certain of the heater elements and piping shown in Figure l are omitted from Figure 2 for.' the sake of clarity. Figure 2 is taken as indicated by thev section line 2 2 on Figure 3.

Figure 3 is a horizontal sectional view taken as indicated by the section line 3 3 on Figure 2.

Figure 4 is a fragmentary view taken substantially as indicated by the section'line 4 4 of Figure 3, illustrating certain portions of the deector and its supporting elements on an enlarged scale as compared with Figure 3.

Figures 5 and 6 are enlarged views of certain details taken as indicated by the lines 5 5 and 6 6 on Figure 3.

Figure? is a partial top plan view of the hood or urnbrella which is arranged aboveeach of the oil treatment trays as shown in Figure 2. f

Figure 8 is a partial plan view of the splash plate ernployed in each of the trays as shown in Figure 2.

In the layout of Figure l, the oil treatment column A is supplied with oil from an oil supply B through' a measuring tank C. The column is provided with a plurality of treatment zones, there being a series oftve` such zones in the particular illustration of Figure l, as i's` indicated by the numerals 1 to 5 inclusive applied tothe column with brackets. Treatments of different kinds are Each zone is desirably; deined by an oil treatment tray arranged within thel carried out in different zones.

column, the ve zones and trays'being serially superimposed. The nature of the trays and of certain parts thereof is described in detailhereinafter with reference to Figures 2 to 8 inclusive, but it is here noted that as shown in Figure 1 the several trays are provided with certain heater elements and steam inlets, as follows: f

In Zone l heating coils 9 are provided, and these may be supplied with steam or other heating medium. Zone'l also is provided with a perforated steam inlet pipe 10 which is supplied from the steam line 11.

In zone 2 heater elements 12 are provided and these may be supplied with a heating medium, for instance Dowtherm vapor generated by the unit D. Steam is introduced into zone 2 through a perforated pipe 13.

Zone 3 as shown in the particular layout of Figure l is not provided with a heater coil but is provided with a stripping steam inlet 14.

Zone 4, in the particular illustration of Figure l, is shown as provided with a heater 15 also supplied from the generator D, as well as a perforated stripping steam inlet plication of Alton E. Bailey, erial No. 54,967, filed October 16, 1948, now Patent No. 2,691,665, issued Oct. 12,1954, and assigned to the assignee of the present ap plicaton.

It may be mentioned briefly that as disclosed in said copending application the type of column illustrated in Figure 1 provides for successive batch-wise treatment of oil, a measured quantity being introduced from the tank C into the tray defining zone 1 and treated therein for a given interval of time, after which this batch is dropped into the tray defining the next zone, and a new batch is introduced into the first zone. Each period of treatment is carried on for the same length of time and each batch of oil is successively dropped into the next lower zone until each batch is subjected to treatment for the given time interval in each of the five zones, following which it is dumped into the receiving tank E below the column. ln such a column the first two trays serve to raise the oil to effective deodorization temperature and in these trays a relatively small amount of steam is introduced, primarily for the purposes of agitating the oil and removing air therefrom. Deodorization takes place in the trays of zones 3 and 4 so that here the steam is being used for stripping. The steam in the tray of zone 5 serves again for agitation.

Advantageously the entire operation carried out within the column is effected under high vacuum and for this purpose a vacuum connection 19 is provided near the upper end of the column, the vacuum being drawn by equipment indicated in outline at F.

With the foregoing in mind as representative of an oil treatment system of the kind in which the steam stripping equipment of the invention may be utilized, attention is now directed to the disclosure of Figures 2 to 8 inclusive.

In Figures 2 and 3 the shell of the treatment column is indicated at 20. Within the shell are the superimposed oil receiving trays which serve to define the several zones of treatment referred to above in connection with Figure 1. Thus, in Figure 2 several of the treatment trays are shown. Each tray has a bottom wall 2l and side walls 22. The uppermost tray shown in Figure 2 only fragmentarily may, for the purpose of this discussion, be assumed to be the tray defining zone 2 in Figure l; and the tray in the central portion of Figure 2 may be assumed to be that defining zone 3`in Figure l. Similarly, the lowermost tray of Figure 2 may be assumed to be that defining zone 4.

It will be observed that the heater coils and stripping steam inlet pipes have been omitted from tie illustration of Figure 2 for the sake of clarity, but it will be understood that these elements are disposed in the lower portions of the trays well below the oil level therein. Such oil level is illustrated in Figure 2 at L. it is also mentioned that the equipment of the invention may be used whether or not heating or cooling coils are present in the treatment trays.

Although the trays or treating vessels may be of any desired shape, from inspection of Figure 3 it will be noted that the trays in this particular illustration are of square horizontal section, leaving open shell space substantially completely surrounding the trays through which the stripping steam and vapors are withdrawn from the several trays independently of each other for ultimate discharge out of the vacuum offtake i9.

Figures 2 and 3 also show the dump pipes 23 through which the oil, after treatment in one tray, is delivered to the next subjacent tray.

As hereinabove mentioned, the equipment of this invention utilizes a splash plate, this being shown at 24 in Figures 2 and 8. As best seen in Figure 8, the splash plate is of generally square shape, although it is cut out appropriately in the region of the dump pipe 23; and the edges of the splash plate are terminated short of the upright side walls of the tray so as to leave a steam exit passage. It will be understood that the plan shape of the splash plate will substantially conform with the plan shape of the particular tray or vessel in which it is used. As clearly appears in FigureZ each splash plate is located at a level well above the level of the oil in the tray, so that when the stripping steam is admitted toward the bottom of the body of oil n the tray, the oil is projected upwardly against the under side of the splash plate in a surging or geyser-like manner thereby causing the oil to splatter and break up into small masses, so as to increase the exposed surface area for contact with the stripping steam.

Above the level of the splash plate a deflector ring 25 is provided, this ring projecting inwardly from the side walls of the tray and overlying the space between the edges of the splash plate and the side walls of the tray, thereby causing the rising steam to converge inwardly from all sides toward the central portion of the superimposed umbrella or hood 26. The marginal edges of this hood are located above and project somewhat beyond the upright side walls 22 of the tray and are supported by spaced brackets 27 so that the steam may escape under the edge of the hood into the shell space. The hood prevents dripping of oil into the tray from surfaces lying above.

Brackets 28 projecting inwardly from the tray walls serve to support the splash plate 24 in the manner explained hereinafter.

ln considering one of the important features of the present invention it is here pointed out that the action of the stripping steam admitted toward the bottom of the body of oil in the treatment tray not only results in projection of masses of the oil upwardly against the splash plate, but also has been found to promote rather high surging of the oil up the side Walls of the tray. This is apparently due to the fact that the stripping steam rapidly expands in the heated oil, thereby displacing oil. When this occurs in the central region of the tray the expansion of the steam and displacement of the oil may take place laterally as well as upwardly; but in the region adjacent a side wall of the tray the lateral displacement of the oil is somewhat restricted, by the very pres ence of the side wall, in consequence of which the oil tends to surge upwardly along the side wall and thus into the steam exit passage around the edges of the splash plate.

According to the invention this surging up the side Walls is effectively prevented by the employment of a deiiector projecting inwardly from the side walls of the tray, as illustrated at 30. This deflector advantageously comprises an imperforate deflector plate (made up, if desired, of a plurality of plate elements) extending all the way around the side Walls of the tray and located wel! below the level of the splash plate, desirably somewhat below the level of the oil in the tray. In a location such as shown in Figure 2, the deflector plate not only prevents the surging of the oil up the side walls of the tray but also serves to deflect or direct such surging inwardly and upwardly against the central region of the splash plate. This further enhances the splashing and splattering effect, which, in turn, increases the surface contact between the steam and oil and thus also the stripping efficiency.

The deflector 30 may be supported within the tray in any suitable manner, as by horizontal angle members 31 extended across the tray from wall to wall just underneath the deflector. These may be arranged in the form of a cross as clearly appears in Figure 3, or in some other appropriate manner. Additional inclined braces for the deflector 30 may be provided above the deflector, as illustrated for example at 32 in Figures 2, 3 and 4. These latter supporting elements are hung from the brackets 28 on which the splash plate is also supported. Reinforcing angles such as shown at 33 may also be provided on the under side of the deflector 30. The deector 30 is desirably downwardly inclined from the side walls of the tray so as to avoid trapping of oil when the batch is dumped from one tray to another.

As best seen in Figures 2 and 8, the under side of the splash plate 24 is provided with a plurality of tins or ribs 34 and 35 which serve not only to reinforce the plate but also to improve the operation of the equipment in several respects. The elements 34 extend across the under surface of the splash plate between diagonally opposite corners; and the elements 35 are arranged in spaced parallel relation in a manner to provide channels extending from the mid or interior region of the splash plate outwardly toward the marginal edges thereof. The several rib or 1in elements 34 and 35 cooperate in providing a tendency for a surge or mass of oil striking the splash plate to be directed toward localized regions of the marginal edges of the splash plate, i. e., they tend to prevent uniform spread of a surge of oil in all directions on the under surface of the splash plate. This is of advantage since in the case of a particularly large surge of oil a uniform spread thereof toward all edges of the splash plate might tend to unduly restrict the steam exit passage around the edges of the splash plate.

The various tins on the lower side of the splash plate are, of course, wetted with oil, and the ns increase the total wetted surface and thereby also increase the surface area of the oil exposed to the action of the stripping steam.

The provision of tins or ribs on a splash plate, as desig nated by numerals 34 and 35, forms no part of the present invention per se, being described and claimed in copending application of Charles N. Maravell, Serial No. 293,462, tiled concurrently herewith, now abandoned.

Certain of the elements 35 project outwardly beyond the edges of the splash plate and are fastened to the supporting brackets 28 to give support to the splash plate, as is clearly shown in Figures 4 and 8.

It will also be noted from Figures 2 and 7 that the umbrella or hood 26 is provided with certain fins on its under side. These, however, are quite differently arranged as compared with those employed on the splash plate. In the case of the hood 26 iins 36 are located in the central region of the hood in the general form of a cross; and additional ns 37 are arranged in rings paralleling the edges of the hood and spaced inwardly from the skirt 38.

It will be observed that the skirt 38 is of greater height than the tins 37 and lies within the contines of the upright tray walls. This skirt, in cooperation with the deilector 25 and also with the uppermost edge of the side walls of the tray provides a tortuous passage for the steam leaving the tray.

In connection with the functioning of the skirt 38 and the ns 37 it is first mentioned that particles of oil entrained by the steam are deposited on the underside of the hood and tend to run on the surface of the hood to a low point and then drop off. The velocity of the steam passing under the skirt 38 and out of the tray is relatively high, so that if an appreciable amount of oil particles dripped from this skirt there would be a tendency for such drops to be carried out of the tray with the steam. The provision of one or more ns such as indicated at 37 spaced inwardly from the skirt 38 provides for dripping of oil back into the tray in a region where the velocity of the steam is lower.

A 1in or rib 39 depends from the underside of the deector ring 25. This provides for dripping of oil back into the body of oil in the tray justbeyond the outer edge of the splash plate. The drip tin 39 is also located in a region where the velocity of the steam is somewhat lower than at the inner stage of the deliector 25, and this aids in reducing the carrying of oil particles with the steam in its passage out of the tray.

The arrangement of drip fins such as indicated at 37 and 39 forms no part of the present invention per se, being described and claimed in copending application of Louis P. Bornwasser, Serial No. 293,463, tiled concurrently herewith.

The use of the detlector 30 in combination with a splash plate, as provided by the invention, results in highly etective splash plate action, while at the same time preventing surging of any substantial quantities of oil into the steam exit passage around the splash plate, so that eiec tive surface contact between the steam and oil is attained while minimizing carry over and loss of oil.

We claim:

l. Equipment for use in steam stripping treatment of oil comprising a vessel having upright side Walls and adapted to receive oil up to a level providing a body of liquid oil only partially filling the vessel, an inlet for introducing stripping steam into the vessel below said level under conditions promoting expansion of steam in the oil and resultant acceleration of masses of liquid oil in a plurality of directions, a splash plate in the Vessel well above said level for breaking up masses of liquid oil projected from said body by the steam and having an edge spaced from a side wall of the vessel to provide an exit passage for steam and Vaporized oil constituents, and a detiector for preventing surging of liquid oil up said side wall of the vessel in the region of the space between said side wall and said edge of the splash plate, said dellector projecting inwardly from the side wall of the vessel at an elevation below said level.

2. A construction according to claim 1 in which the deector comprises an imperforate plate.

3. A construction according to claim 1 in which the deector projects inwardly from the side wall of the vessel a distance greater than the distance of spacing of the edge of the splash plate from the side wall of the vessel.

References Cited in the le of this patent UNITED STATES PATENTS 920,721 Bradley May 4, 1909 1,170,069 lhrig Feb. 1, 1916 1,214,372 Romberger Ian. 30, 1917 1,683,826 Huff Sept. 11, 1928 1,773,073 Beach Aug. l2, 1930 1,789,004 Krauel Jan. 13, 1931 1,870,193 Grahame Aug. 2, 1932 1,897,766 Primrose Feb. 14, 1933 2,099,802 Ewing Nov. 23, 1937 2,491,645 Clark et al Dec. 20, 1949 2,692,129 Wilson et a1. Oct. 19, 1954

Claims (1)

1. EQUIPTMENT FOR USE IN STEAM STRIPPING TREATMENT OF OIL COMPRISING A VESSEL HAVING UPRIGHT SIDES WALLS AND ADAPTED TO RECEIVE OIL UP TO A LEVEL PROVIDING A BODY OF LIQUID OIL ONLY PARTIALLY FILLING THE VESSEL, AN INLET FOR INTRODUCING STRIPPING STEAM INTO THE VESSEL BELOW SAID LEVEL UNDER CONDITIONS PROMOTING EXPANSION OF STEAM IN THE OIL AND RESULTANT ACCELERATION OF MASSES OF LIQUID OIL IN A PLURALITY OF DIRECTIONS, A SPLASH IN THE VESSEL WELL ABOVE SAID LEVEL FOR BREAKING UP MASSES OF LIQUID OIL PROJECTED FROM SAID BODY BY THE STEAM AND HAVING AN EDGE SPACED FROM A SIDE WALL OF THE VESSEL TO PROVIDE AN EXIT PASSAGE FOR STEAM AND VAPORIZED OIL CONSTITUENTS, AND A DEFLECTOR FOR PREVENTING SURGING OF LIQUID OIL UP SIDE WALL OF THE VESSEL IN THE REGION OF THE SPACE BETWEEN SAID SIDE WALL AND SAID EDGE OF THE SPLASH PLATE, SAID DEFLECTOR PROJECTING INWARDLY FROM THE SIDE WALL OF THE VESSEL AT AN ELEVATION BELOW SAID LEVEL.

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