US 3365860 A
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Jan. 30, 19 68 JEAN-MATHIEU BORIS METHOD AND APPARATUS FOR TREATING LIQUIDS WITH GASES Filed Feb. 3, 1966 3 Sheets-Sheet l Jan. 30, 1968 JEAN-MATHIEU BORIS METHOD AND APPARATUS FOR TREATING LIQUIDS WITH GASES Filed Feb. 5, 1966 3 Sheets-Shed 2 Fig.6
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26w Zflfiku BORi 5 m you: i QM Hamlin E75 United States Patent 3,365,866 METHGD AND APPARATUS FOR TREATHNG LIQUIDS WITH GASES Eean-Mathieu Itoris, Paris, France, assignor to Gleostin, Paris, France, a French company Filed Feb. 3, 1966, Ser. No. 529,963 Claims priority, application Luxembourg, Feb. 6, 1965,
4 Claims. ici. ss-s4 AESTRAQT OF THE DISCLGSURE The present invention relates primarily to an apparatus intended for improving gas-liquid contacts and notably deodorizing oils by the socalled steam stripping process or the hydrogenization of fatty substances.
The steam-stripping oil deodorizing process consists essentially in eliminating the odorous components in a steam current by distillation under reduced pressure and at a relatively high temperature.
In known apparatus of this character which operate continuously, semi-continuously or batchwise, the quantity of steam implemented ranges as a rule from 175 to 225 cu. ft. of steam per pound of oil to be treated. The higher the vacuum, the shorter the distillation time, and modern apparatus operate generally under vacuum values ranging from 2 mm. Hg to 6 mm. Hg.
In existing apparatus steam is blown into the oil mass at the bottom of the vat and the pressure prevailing at the injection point is equal to the pressure prevailing at the liquid surface in the vat, plus the pressure corresponding to the liquid column overlying said injection point. Thus, in the case of a vat containing about ten feet of oil subjected to a 2-mm. Hg vacuum the pressure at the injection point is of the order of 200 mm. Hg. As a matter of fact, in this vat a pressure lower than the value consistent with a satisfactory distillation (about 25 mm. Hg) is found only in the top layer, about twelve inches deep, of the oil mass. In certain apparatus steam is injected into the base of a duct emerging above the oil level, and this steam bubbles upwards and entrains the oil; however, this current is not attended by a corresponding pressure reduction at the base of the duct.
It is the essential object of the present invention to provide an apparatus designed for improving gas-liquid contacts, notably for deodorizing oils by means of steam, of the type comprising a vat for receiving the liquid to be treated, a duct open at its base and top which is mounted in said vat, and means for injecting gas into said duct. This apparatus is remarkable notably in that throttling means are provided in the lower portion of said duct for controlling the rate of feed of the oil in troduced into it, whereby the density of the emulsion column produced in said duct can be kept at a relatively low value, preferably below one-tenth of that of the treated liquid.
According to this invention a very fine emulsion of steam and oil in controlled proportions is created at the base of said duct, the oil input being adjusted by said throttling means, and the steam input by other means disposed for example externally of the vat.
3,365,860 Patented Jan. 30, 1968 ICC It will be noted that as the oil circulation in said duct is induced by the pressure dilferential created between the oil column and the emulsion column, it is possible according to this invention to obtain an emulsion having the desired density and to control the rate of upward flow of said emulsion in said duct by adjusting the oil feed rate and the corresponding steam feed rate. With this arrangement, emulsions having a density lower than .08 and even as low as .001 have been obtained in practice. It may also be noted that in the case of a vat filled with ten feet of oil, the density being .08 and the vacuum value constantly maintained at 2 mm. Hg, the pressure obtaining at the injection point is of the order of 25 mm. Hg, that is, consistent with the requirements of a satisfactory distillation, these conditions being maintained throughout the time in which the steam contacts the liquid to the top of said duct. With a density of .001 the pressure at the injection point is of the order of 5 mm.I-Ig.
In an apparatus constructed according to the teachings of the present invention it has been possible to deodorize oil by consuming steam at the rate of 32 cu. ft. per pound of oil, the treatment time being reduced to less than 10 minutes, the corresponding treatment time being at least one hour in known apparatus.
In addition, by reducing the injected steam feed rate it has been possible to load the apparatus up to about 14 inches from the commencing vacuum without any risk of producing untimely entrainments.
Other features and advantages of this invention Will appear as the following description proceeds with reference to the accompanying drawings, in which:
FIGURE 1 illustrates diagrammatically in fragmentary axial section an oil deodorizing apparatus constructed according to the teachings of this invention;
FIGURE 2 is a cross-section taken upon the line IIII of FIGURE 1;
FIGURE 3 is another-fragmentary axial section showing on a larger scale the lower portion of one of the ducts incorporated in the apparatus of FIGURE 1, ac cording to a first form of embodiment;
FIGURE 4 illustrates in axial section the lower portion of one of the ducts of the apparatus of FIGURE 1 but according to a modified form of embodiment;
FIGURE 5 illustrates in axial section the lower portion of one of the ducts of the apparatus of FIGURE 1 but according to a third form of embodiment;
FIGURE 6 illustrates in axial section an apparatus comprising a non-rectilinear duct according to a modified construction;
FIGURE 7 illustrates in longitudinal vertical section a deodorizing apparatus designed for continuous operation, according to this invention;
FIGURE 8 is a horizontal section taken upon the line VIII-VIII of FIGURE 7.
Referring firstly to FIGURES l and 2 of the d awings, an apparatus according to this invention for improving the gas-liquid contacts comprises a vat it of which the upper portion broken away in the drawing is connected to a vacuum pump or like suction unit. The chain-dotted line 12 designates the oil level in the vast- It). This oil is introduced into the vat 1d through a bent pipe 14 and heated by a coil system comprising two coaxial series of turns 16 and 13, this heater being adapted to heat the oil at a temperature of the order of 300 to 390 F. to 200 C.)
Mounted at spaced intervals in. this vat 1d are four cylindrical ducts or chimneys 20 open at their lower and upper ends, and provided with baffle means 22 overlying their upper ends. These ducts 20 are retained in position at their lower and upper ends by a strip-iron and tie-rod system (not shown) co-acting with the lateral walls and the bottom of the vat.
As already explained hereinabove, the oil is deodorized by causing it to contact steam injected into the lower portion of the ducts 29 to create a fine emulsion therein. The steam is introduced into each duct through the branch pipes 24 of a vertical feed line 26 disposed centrally of the vat.
The means for injecting steam into the ducts 28 will now be described .with reference to the various forms of embodiment illustrated in FIGURES 3-5.
FIGURE 3 shows in axial section the lower portion of one of the ducts of FIGURE 1. In the specific form of embodiment illustrated in FIGURE 3 there is mounted within the lower portion of each duct 20 a sleeve-like body of revolution 28 constituting a lower convergent 30 connected through an intermediate throttling 34 to an upper divergent 32. Slightly upstream of this throttling 34 is the outlet nozzle 36 formed by the upper end of the steam feed line 24. Preferably and as shown the convergent 30 has a relatively wide vertex angle and the divergent 32 has a relatively small vertex angle, in order to improve the power recovery.
FIGURE 4 illustrates in axial section the lower portion of one of the ducts of FIGURE 1, according to a modified form of embodiment. In this alternate form of embodiment the lower portion of duct 20 is closed by a transverse plate 46: in which a central orifice 42 is formed. The means used for injecting steam into the device consists of a relatively thick assembly comprising two annular coaxial stacked plates 46 and 48, the former or lower plate 46 comprising an annular groove 50 constituting a steam header for distributing the steam to a series of radial grooves 52 opening into the central aperture of the annular assembly -46, 48, these grooves being covered by the lid-forming upper plate 48. The annular groove 50 is connected through a branch pipe 54 to the steam feed line 24 which, in this example, is passed through the lateral wall of duct 20. Overlying, and spaced from, the annular assembly 46, 4-8 is a perforated plate or grid 56 through which the emulsion is caused to how upwardly during the operation of the apparatus.
FIGURE 5 shows another form of embodiment of this invention wherein the duct 250 closed at its bottom by a plate 58 formed with a central orifice 69 comprises an injection system consisting of a substantially cylindrical box-like assembly 62 disposed coaxially to the inner space of said duct and provided with a lid 5'4 crimped or otherwise secured to the lateral walls of said box-like assembly 62; this lid 64 consists of a porous material adapted to divide the steam into very fine bubbles in order to produce a perfect emulsion. The box-like assembly 62 is supplied with steam through a pipe 66 mounted in this example through the lower portion of the lateral wall of duct 20.
Of course, it would not constitute a departure from the scope of the invention to substitute adjustable throttling means such as valves or the like for the plate 46 of FIG- URE 4, and 58 of FIGURE 5.
FIGURE -6 illustrates another form of embodiment of an emulsionduct wherein this duct is of sinuous configuration in order to increase the length of the path followed by the emulsion up the duct. The apparatus shown in FIGURE 6 comprises a vat 70 heated by a coil system 72 and conected through a pipe 74 to suction means (not shown). Oil is fed thereto through a pipe 76. A duct 78 provided at its top with a suitable bafi'le member 8d has the shape of a long-pitched spiral. Fastening means (not shown) are provided at the top and bottom of the duct. Steam is injected through injection means of the type set forth hereinabove with reference to FIGURES 3 to 5 into the duct 78.
Of course, the turns of the duct shown in FIGURE 6 may have any other suitable configuration in lieu of the spiral shape illustrated. Thus, the turns may be coplanar.
In certain cases the emulsion path through the duct may be increased by inclining a straight duct mounted in the vat.
In the various apparatus described hereinabove the dimensions of the throttling means, (i.e. neck 34 of convergent-divergent unit 28, orifices 42 or "66 of plates 40 and 58, respectively) may be so calculated that, considering the steam input injected into the duct, the oil input supplied through said throttling will permit of maintaining an emulsion column of relatively and sufiiciently low density, preferably less than one-tenth of the density f the treated liquid.
FIGURES 7 and 8 illustrate a continuous oil treatment plant or apparatus comprising emulsion ducts of the type described with reference to FIGURES 3 to 5 of the drawings and disposed in series.
in these figures the reference numeral 9t) designates the treatment vat and 92a, 9211, 20 9211 are a series of substantially vertical ducts aligned in said vat 9t) and held in position by suitable fastening means (such as tierods), not shown in the drawing. These ducts fizz, 92b, 92c 9211 are separated from one another by vertical Water-tight partitions 94a, 94b, 94c 9411 and include at their tops baffle members 96a, S tb, 6c 96:2
r having frustoeonical lower portions or bases 93a, 9812,
vac 9311 and fitted on the tops of the corresponding ducts, in this example.
These battle members 96a, 9&1), Q60 9611 have in plan view an elongated shape and extend partly beyond the relevant partitions 94a, 9411, $40 9411, respectively.
The oil to be treated is introduced into the vat by means of a pipe line 10% opening into a first compartment bounded by the lateral wall of the vat and by the first partition 94a. The treated oil is discharged from the last compartment of the apparatus by means of a drain pipe 164, this last compartment being bounded by the lateral wall of the vat and by the last inner partition 9411. Steam is introduced through a manifold pipe 1% passing in a fluid-tight manner through the wall of said vat 9t and through each inner partition 94a, 94b, 94c 412 and leading to injection nozzles litia, 111911, Title 11%.
In this example the steam injection nozzles have their outlet orifices disposed slightly upstream of the corresponding throttling of the diver ent-convergent system 1% mounted in the lower portion of the ducts, but it would not constitute a departure from the spirit and scope of the invention to resort to other means, for example those illustrated in FIGURES 4 and 5.
Of course, adequate heating and possibly cooling means (not shown) are associated with the vat 9b, and the top of this vat is connected to a suction or vacuum unit (not shown).
This apparatus operates as follows:
The oil introduced through the pipe 130 into the first compartment of the vat penetrates into the duct 92a as shown by the arrow. The very low-density emulsion created at the outlet of the convergent-divergent 166 as a consequence of the injection of steam through the injection nozzle a rises in the duct 92:: and falls into the second compartment formed between partitions 94a and 94b. The emulsion guided by the bathe member -Sa is thus prevented from falling back into the first com partinent. Thus, the oil to be treated passes in succession through the different ducts 92a, 92b, 92c 92a and then into the last compartment from which it is discharged through the drain pipe 31M.
The various apparatus constituting the subject-matter of the present invention may also advantageously be used for hydrogenizing various substances, notably fatty substances.
In fact, it is known that the use of a continuous foamy condition in hydrogenization processes permits of reducing the reaction temperature, improving the quality of the hydrogenization products, reducing the formation of solid iso-oleic acids and increasing yields due to the reduction of the acid number of the hydrogenated fatty substance.
The continuous apparatus according to this invention may be used as a hydrogenizer under foamy conditions and in this case it will provide contact times 4 to 20 times shorter than those required with known continuous apparatus for a same coefiicient of selectivity.
What is claimed is:
1. Method for deodorizing an alimentary oil with steam comprising introducing oil into an enclosed tank, said tank containing at least one substantially vertical open ended duct spaced from the top and bottom of said tank and a bathe member overlying the top of said duct with a convergent-divergent unit housed in the lower portion of said duct having a relatively narrow intermediate throttling, said convergent-divergent unit having a pressure steam injection nozzle opening axially thereinto slightly upstream of said throttling, filling said tank with said oil to a sufiicient height for the surface of said oil to be above the top of said duct and spaced from the top of said tank, creating a vacuum within said tank, introducing steam into the open end of the base of said duct to form an emulsion of said oil and said steam, controlling the input of said steam and the flow of said oil into said duct to provide said emulsion with a density less than one-tenth that of said oil and an injection pressure of said steam no greater than 25 mm. Hg thereby creating an upward stream flow of said emulsion through said duct and steam-oil treating contacts throughout the length of the duct.
2. The method of claim 1 wherein said vacuum has a value in the range of 2 to 6 mm. Hg.
3. The method of claim 2 wherein said oil height is ten feet, said emulsion density is 0.08, said vacuum has a value of 2 mm. Hg and said steam injection pressure is 25 mm. Hg.
4. The method of claim 2 wherein said oil height is ten feet, said emulsion density is 0.001, said vacuum has a value of 2 mm. Hg and said steam injection pressure is 5 mm. Hg.
References Cited UNITED STATES PATENTS 2,163,303 6/1939 Bonotto 203-96 2,273,852 2/1942 Ferreira 261--l24 X 2,715,521 8/1955 Tatibana 261l23 X 2,919,232 12/1959 Stingley 26l-123 X 3,054,602 9/1962 Proudman 26 l122 X 3,129,076 4/1964 De Smet 5554 SA'MIH N. ZAHARNA, Primary Examiner.
REUBEN FRIEDMAN, Examiner.
R. W. BURKS, Assistant Examiner.