US3172922A

US3172922A - Kehse deodorizing apparatus

Info

Publication number: US3172922A
Authority: US
Publication date: 1965-03-09
Anticipated expiration: 1982-03-09

Description

w. KEHSE DEODORIZING APPARATUS March 9, 1965 5 Sheets-Sheet 1 Filed 001,. 31, 1960 March 9, 1965 w. KEHSE DEODORIZING APPARATUS 3 Sheets-Sheet 2 Filed Oct. 31. 1960 IN VEN TOR.

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March 9, 1965 w. KEHSE 3,172,922

DEODORIZING APPARATUS Filed Oct. 31, 1960 3 Sheets-Sheet 3 A f/6H7 or 1/00/47 LA new VACl/l/M United States atent G 3,172,922 DEODQRIZING APPARATUS Wolfgang Kehse, Beriin-Zehlendorf, Germany, assignor to Pintsch-Bamag A.G., Berlin, Germany Filed Oct. 31, 1960, Ser. No. 66,265 Claims priority, application Germany, Get. 39, 1959, P 23,798 5 Claims. (Cl. 261-20) The present invention relates to a deodorizing apparatus, and more particularly, the present invention is concerned with deodorizing fats and oils with steam.

Such deodorization has been carried out by passing oil over a plurality of superposed perforated bottoms, in countercurrent flow with steam, the oil passing in downward direction and the steam upwardly, so that fresh steam will come in contact with oil which previously has been contacted by steam and crude oil will be contacted with steam which previously has passed through the oil layers on the perforated bottoms further below. In order to carry out this process, a pressure diiierential must exist between the pressure at which steam is introduced into the device and the pressure at which steam is withdrawn therefrom. By using an arrangement as described above, wherein the steam passes successively through a plurality of perforated bottoms each carrying a layer of oil, the pressure differential or partial vacuum in each individual contact area between oil and steam, and particularly on top of the lowermost bottom where substantially pure oil is to be freed from residual odoriferous constituents is relatively small. The residual pressure or partial vacuum at the lowermost perforated bottom will be substantially equal to the total pressure difference between the steam pressure and the reduced pressure at which spent steam is withdrawn above the uppermost perforated bottom, minus the reduction in pressure which will occur above all of the individual perforated bottoms with the exception of the lowermost one. Thus, these prior art methods and devices possess certain shortcomings particularly with respect to substantially complete deodorization of the raw material.

It is therefore an object of the present invention to overcome the above discussed disadvantages of prior art devices and methods.

It is another object of the present invention to provide an apparatus for effectively deodorizing materials such as organic, fats and oils in an efiicient, simple and economical manner.

Other objects and advantages of the present invention will become apparent from a further reading of the description and of the appended claims.

With the above and other objects in view, the present invention contemplates in an apparatus for the continuous deodorization of fats, oil and the like, in combination, a tower, a plurality of transverse foraminous walls arranged in the tower one above the other, means for guiding material to be treated downwardly from one foraminous wall to the next lower foraminous wall, means cooperating with the underside of each foraminous wall and defining a steam chamber therewith so that steam in several chambers will pass upwardly through the foraminous walls to the material being treated, means for introducing steam under pressure into said steam chambers, respectively, and steam withdrawal means maintained at a lesser pressure and communicating with the Space between each foraminous wall and the steam chamber thereover for removing spent steam from the space and out of the tower, the withdrawal means preventing communication between the spent steam of any one space with any other space.

In a preferred embodiment of the apparatus of the present invention, the same comprises, in combination, an upright tower, a plurality of transverse foraminous walls formed of sintered metal arranged in the tower one above the other, means for guiding material to be treated downwardly from one foraminous wall to the next lower foraminous wall and for constraining the material to flow along a predetermined path over each foraminous wall, means cooperating with the underside of each foraminous wall and defining a steam chamber therewith so that steam in several chambers will pass upwardly through the foraminous walls to the material being treated, means for introducing steam under pressure into the steam chambers, respectively, and steam withdrawal means including a plurality of superposed tubular members extending coaxially with the tower, the cross sectional dimensions of the upper end portions of each of the tubular members being greater than the cross sectional dimensions of the lower end portions thereof and the lower end portions of all but the lowermost of the tubular members being inserted into the upper end portions of the next lower tubular member so as to form an annular chamber therebetween communicating with the space between each foraminous wall and the steam chamber thereover for removing spent steam from the space and out of the tower, conduit means passing through the foraminous walls, respectively, and extending from a point in the lowermost portion of the respective steam chamber to the upper face of the foraminous wall thereof, whereby material to be treated and located in the steam chamber will be forced by the steam under pressure to pass through the conduit means to the upper face of the foraminous wall, the withdrawal means preventing communication between the spent steam of any one space with any other space.

Thus, the apparatus of the present invention permit continuous deodorization of vegetable and animal fats and oils by contacting the same with subdivided steam in such a manner as to overcome the difficulties heretofore experienced in this field.

It is essential according to the present invention that steam passes from a steam chamber through a Wall thereof which is foraminous and preferably contains a very large number of very small conduits for passing of steam therethrough. The outer face of the foraminous wall of the steam chamber forms the bottom of a treating chamber. Along this bottom, a stream of oil is flowing, preferably along a tortuous path, so that the steam in finely subdivided form will penetrate and pass through the stream of oil transverse to the direction of flow thereof. The steam emanating from the upper surface of the oil or the like which is to be treated will contain volatile odoriferous substances thereof and the thus spent steam will then be withdrawn without subsequently coming in contact with additional oil or the like. The oil is preferably forced to pass along the upper surface of the perforated wall in tortuous or meandering, for instance spiral, channels so that the oil along a relatively long path while flowing along the upper face of the perforamed wall will be contacted with finely subdivided uncontaminated steam.

The steam chamber, furthermore, includes a device for the removal of oil which, for instance during interruption of the process or upon lowering of steam pressure might have passed through the foraminous wall into the steam chamber. Removal of oil is automatically accomplished by arranging in the steam chamber one or more tubular members of relatively small diameter which extend from points in the lower portion of the steam chamber upwardly to the upper face of the foraminous v'all. Upon introducing steam of sufiicient pres sure into the steam chamber, the steam will force any serving as treating chamber.

oil that might have collected in the lower portion of the steam chamber through such tubular member to the upper face of the foraminous wall where the thus-returned oil will join the flow of oil described further above.

Several steam chambers may be arranged superposed upon each other, each having a foraminous top wall which at the same time forms the bottom wall of the treating chamber along which the stream of oil flows successively from the uppermost towards the lowermost treating chamber. The height of the flowing oil in each of the treating chambers, i.e., the flow along the upper faces of the foraminous walls, is controlled by overflow conduits which withdraw oil from the upper treating chamber and pass it into the next lower treating chamher.

The spent steam of each of the individual treating hers is sucked into a centrally arranged steam withdrawal conduit formed with openings communicating, respectively, with each of the treating chambers above the level of the oil therein. These openings are preferably in the form of annular channels so arranged that any condensate formed therein will not drop back into the treating chamber but will be guided downwardly towards the lower end of the withdrawal conduit. Due to the fact that all of the treating chambers communicate with one and the same withdrawal conduit, the same pressure or partial vacuum will be maintained in all of the treating chambers, or, in other words, the pressure diiferential between communicating steam chambers and treating chambers will be the same throughout the entire apparatus.

The oil is preferably guided along the foraminous bottoms of the individual treating chambers in such a manner that the direction of flow of the oil is substantially opposite to the direction of flow of spent steam towards the central withdrawal means. This can be accomplished for instance by guiding the oil in the treating chamber along a spiral path so that the oil is introduced substantially in the center area of the treating chamber and is withdrawn from a point in the peripheral area of the treating chamber, from there flowing through the overflow conduit to the central portion of the next lower treating chamber, thus moving towards the periphery of the treating chamber, while the spent steam is sucked into the withdrawal conduit in the center portion of the chamber thus moving from the periphery towards the center of the treating chamber. In this manner, it is accomplished that any oil droplets which might be carried along by the spent steam and then drop back into the flowing oil, will not be dropped back into an area in which the flowing oil has been further deodorized than in the area in which the oil was carried away by the steam.

While, generally, the device of the present invention will consist of a plurality of superposed steam and treating chambers, each unit having a foraminous wall separating the steam chamber from the superposed treating chamber, it is also possible to use only one steam and treating chamber respectively which in such case will be made correspondingly larger. For instance, a horizontal cylinder of preferably oval cross section may be divided by a horizontally extending toraminous wall into a lower portion serving as steam chamber and an upper portion In such cases means must be provided for forcing oil to flow on the upper face of the foraminous wall or insert in a tortuous path from one end of the cylinder to the other.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing, in which:

FIG. 1 is an elevational view in cross section of a device according to the present invention which coniprises a plurality of superposed steam and treating chamber units;

FIG. 2 is a cross sectional view along line A- B of FIG. 1;

FIG. 3 is a schematic perspective view further illustrating certain essential features of the devices of FIGS. 1 to 2;

FIG. 4 is a graphic representation of the cooling of an oil layer depending on the height of the same;

FIG. 5 illustrates additional considerations affecting the optimum height of the oil layer;

FIGS. 6 and 7 are schematic and graphic representa tions of the influence of variations in the cross-sectional shape of the oil with respect to the deodorization thereof;

FIG. 8 is a graphic illustration of the influence of the height of the oil layer on the effectiveness of the steam used for deodorizing the oil; and

FIG. 9 is a flow sheet of an oil deodorization installation embodying the present invention.

Referring now to the drawing and particularly to FIG- URES l and 2, it will be seen that the entire apparatus is closed at its top by cap 2 formed with a central opening 3 through which the spent steam vapors are sucked off preferably at lower than atmospheric pressure which is provided by conventional means not illustrated in the drawing. Several steam chambers 4 are arranged superposed upon each other each formed with an upper foraminous wall 5. Fresh steam is introduced into each of the steam chambers through correlated conduit 6 and passes upwardly through foraminous wall 5 into the coordinated superposed treating chamber which extends upwardly to the lower wall of the next superposed steam chamber 4. The steam passes through foraminous wall 5 into the flowing layer of oil '7. In order to achieve the desired fine distribution of the steam entering into all layer 7, foraminous wall 5 is made of sinter metal or of finely perforated sheet metal. Oil is introduced into the uppermost treating chamber through conduit 8 and is forced along a tortuous path on the surface of foraminous walls 5, by vertical sheet metal walls 9, forming together with portions of foraminous wall 5 channels for the passage of oil therethrough. As can be seen in FIGURE 2, these channels may be arranged concentrically about the withdrawal conduit 11 arranged coaxially with the tower formed by the entire device. Gaps in the channel walls allow passage of the oil from one concentric path to the next one in outward direction as indicated by the arrows in FIGURE 2. The steam, after passing through oil layer 7 will flow through the upper portion 10 of the respective treating chamber wherein oil droplets carried along by the steam will separate from the same and fall down wardly into the flowing oil 7. Thereafter, the steam will be sucked into the annular channels 12a leading into central withdrawal conduit 11. The annular conduits 11a are preferably formed by inserting the lowermost portions of individual segments of withdrawal conduit 11 into uppermost portions of the next lower segments, which uppermost portions are of increased diameter so that a channel 11a will be formed between the walls of the end portions of successive segments of withdrawal conduit 11. The last described arrangement has the advantage that any condensate formed upon sucking steam into annular conduit 11a will not be returned into treating chamber 10 but will run downwardly on the inner wall of withdrawal conduit 11 towards the lower end portion thereof where the condensate which contains a considerable amount of the odoriferous substances removed from the oil or the like can be withdrawn from pipe 14-. The oil which has been introduced into the uppermost treating chamber through conduit 8 will pass into the next lower treating chamber through overflow conduit 12 and in the same manner through subsequent treating chambers so that the entire material which is to be treated will pass through all of the channels formed in all of the treating chambers until the deodorized material is finally withdrawn through conduit 12 of the lowermost treating chamber. Conduits l2 serve also to maintain the upper level of the flowing oil or tLe like at the desired height in all of the treating chambers. When for any reason the steam supply through conduits i3 is shut off or steam pressure is considerably reduced while the channels are filled with oil, it might happen that portions of the oil pass downwardly through the foraminous walls into the corresponding steam chambers. Any appreciable accumulation of oil in the steam chambers could cause difficulties upon subsequent restarting of the operation and it is therefore desirable to remove automatically any such oil accumulation. This is accomplished by providing conduits 13 which extend from the upper face of foraminous wall 5 into the lower portion of steam chamber 4. Any oil collecting in the lower portion of steam chamber 4 will then be pushed upwardly through conduit 13 by pressurized steam entering steam chamber 4 through conduit 6. In other words, during operation of the device, the pressure in steam chamber will be higher than on the upper face of foraminous wall 5. This pressure differential is required in order to force steam through foraminous wall 5 and to overcome the hydraulic pressure of the layer of oil or the like.

Furthermore, in order to cover heat losses in the apparatus and in order to keep the flowing layer of oil or the like at a desired temperature, heating means such as conduits 15 of semi-circular cross section are welded onto the outer walls of the tower adjacent to the flowing oil layer, and a suitable heating medium such as steam is passed through the heating conduits 15. For instance, when it is desired to carry out a high temperature deodorization, steam at hi h pressures such as 150 atmospheres and a corresponding temperature may be passed through conduits 15.

The principal component of a continuous deodorizer is shown in FIG. 3, in the form of a canal or duct which is horizontally subdivided into three zones. Through the center zone flows the oil; the bottom zone is supplied with distilling steam. The partition Wall between these two zones is penetrable, so that steam will bubble through the total surface of the oil. The resulting vapors are withdrawn above the oil level, in counterfiow to the oil flow. It is essential that the vapors flow in counterflow to the oil, in order to prevent, as far as possible, entrained drops, if any, from falling back into a zone which is already further deodorized. It is moreover essential to distribute the steam as finely as possible in the oil and, therefore, the surface of the steam chamber is either porous or is provided with a uniform fine-perforation.

The capacity of the deodorizer depends on the required retention period which is determined by the cross sectional dimension of the oil duct, its length, and the speed of oil flow.

The operating temperature depends on the kind of oil to be treated and may reach a maximum of about 240 C. However, maximum allowable working temperatures for deodo-rization differ in various countries.

The vacuum will be approximately in the order of magnitude of 5 mm. All the following considerations are based on this degree of vacuum. A very essential factor of the operating cost is the steam quantity applied per kg. of oil, as this factor appears twice in the cost calculation, on the one hand directly with the steam cost and on the other hand indirectly, because increased steam supply requirements raise the costs and the operating expenses of the vacuum equipment quite considerably. If the operating cost is to be kept as low as possible, the consumption of steam is to be looked at with particular attention. Therefore it is important to consider which cross sectional shape of the oil flow will give optimum results with regard to steam consumption, whether, with equal cross sections, a wide surface would be preferable to a narrow, high shape of the flow canal.

The steam fed into the apparatus is to carry out two different tasks. On the one hand, the steam is supposed to reduce the distilling pressure of the odoriferous matters and on the other hand, by increasing the outer surface by the total surface of all steam bubbles, the useful distillation surface is increased. The steam leaving the liquid layer at bottom is expanding on. its way up. It is not precisely known which laws are followed by this expansion, but it is surely not an adiabatethe isotherm may be much closer to the actual conditions. This expansion process which is hardly a factor in a standard distilling column with bubble cap or perforated trays, is of much more importance in the present process, because the static pressure of the liquid layer amounts easily to a multiple of the operating vacuum, thus causing an expansion ratio, the consequences of which, contrary to the conventional distillation arrangementscan no longer be neglected.

Considering an isothermic process, the amount of heat absorbed by the steam during its expansion can be easily calculated. This heat quantity must be transferred from the oil to the steam and cools the oil down. It is encountered in the form of the stirring action which the steam performs on account of its expansion. How big this cooling is, is represented in FIG. 4 which shows the cooling of the oil layers of varying weight at a fed steam quantity of 5%. As this is far from the boiling point, the steam is calculated as ideal gas. In this connection, the following is to be considered: The cooling values shown in this curve are relative to the entire oil volume. It is necessary, however, to transfer the heat quantity at the inner surface of the bubble from the oil to the steam; without this heat transfer, with an adiabatic expansion, the steam would cool down very intensely. For example: Taking a liquid level of about 1 m. and a vacuum of 5 mm., it would cool from 230 C. to 0 C. In other words: The temperature of the internal bubble surface will be much lower than the average temperature values shown in the picture. This, of course is in itself an undesirable situation: Exactly the surface through which the fatty acid remainders and odoriferous matters are to be distilled and which actually should be heated, is cooled down, and, moreover, the higher the liquid level the more intense the cooling.

Another dependency which gives a very well defined indication for an optimum height of oil layer is illustrated in FIG. 5.

A steam bubble supposed to be spherical leaves the nozzle at bottom. At this point it is affected by the steam pressure p which is the degree of the vacuum or residual pressure-plus Ppr-WhlCh is the pressure corresponding to the static liquid level. When the bubble has risen by the distance 11, its diameter has grown to D because the pressure has been reduced to the amount p +p When the bubble has reached the surface it is affected only by the pressure p and the diameter has increased to D On condition of the isothermal expansionp V =p V there is a relation between the two diameters, as below:

X n (f u+pol h (P(Hh +P Assuming at the level of h, an arrangement of such a number n of bubbles with a diameter D that their volume in consideration of the specific gravity under the pressure at the level it will just contain 1 kg. steam, it will be possible to find from the surface of these :1 bubbles the surface per kg. of steam in any liquid height. This relationwithout making reference to the intermediate relationreads:

It is composed of:

One indiscernable constant which, however, seems to be immaterial as only proportionality factors are considered.

The reciprocal value of the bubble diameter at which the individual bubbles are issued from the nozzle. This bubble diameter depends essentially on the bore of nozzle only, in other words: the finer the nozzle, the larger the surface per kg. of steam.

A term which is constant at any height of layer and which contains the vacuum and the liquid level.

And a term with broken exponents which varies with the actual bubble levels.

7 The evaluation of this function is represented in FIG. 6. It shows arrangements with uniform oil cross sections, but with the liquid levels at l m., V2 m. and 20 cm. In the arrangement with the highest level, the surface per kg. steam varies between about 0.75 and 4.5. In the arrangement with the level at about 500 mm, the surface varies from approximately 1.2 to 5.5, and in the arrangement with the level at about 200 mm., between about 3.2 and 7. Effective for the distillation is the medium surface per kg. of steam, which the bubbles form on their way through the liquid. This can be easily determined by means of graphic integration through the height of layer. The dependency of this medium, effective surface of the layer height is shown in FIG. 7. In a layer having a height of 2 m. a value of 1.6 is obtained, and in a layer having a height of 20 cm. the value 8.9 is obtained. The medium surface per kg. of steam, consequently, increases very much with decreasing layer height. In order to obtain a clear picture of which height of the layer offers optimum utilization of steam, the following has to be taken into account:

(1) Distillation should occur from the inner surface of the steam bubble; therefore, for the present purpose, as said above, the applicable measuring value is the medium inner surface per kg. of steam.

(2) The quantity of fatty acid and/ or odoriferous matters which, at a constant temperature, is distilled through this surface, is surely depending on the absolute pressure which acts within the steam bubble. This absolute pressure-disregarding the capillary pressure-depends on the vacuum and on the height at which the steam bubble is actually in the layer. Effective is thus the pressure in the middle of height of the layer.

(3) The third factor taking effect during the distillation is the period of time during which a steam bubble is Within the liquid. The rising speeds of these steam bubbles have been investigated many a time. Accordingly, it probably will not be a great mistake to consider them more or less as constant, so that the retention period will be about proportional to the height of the layer.

By combining these three influences a value of effectiveness of the distilling steam may be defined and, in FIG. 8 will be found this value of effectiveness above the layer height. This function shows now an explicit maximum at layer heights from 200 mm. to 300 mm. and gives a useful indication with regard to the design of the apparatus.

To recapitulate the assumption made herein for finding this value of effectiveness:

(1) That isothermal conditions are prevailing in all parts. Actually the expansion is not strictly isothermal but it proceeds in accordance with apolytropic reaction, however, which inclines rather to the isothermal than to the adiabatic side. But this can only strengthen the concept of the optimum liquid level for, due to the cooling of steam with strong expansion, the medium surface will decrease more at higher layers than at lower layers.

(2) An almost spherical shape of the bubbles has been presumed. If the form of the bubbles is substantially different from the spherical shape, this can change the absolute measure of surface per kg. of steam, but surely not so much the variation of this surface with the height of layer, unless the steam quantity would so much increased, that no individual bubbles would be formed, but

that, at times at least, a steam jet would force its way upwardly through the liquid. In this case, the above c0n templations no longer would be applicable.

(3) It is further assumed that the steam bubbles issued from the nozzle have a more or less equal diameter, independent of the thickness of the oil layer.

(4) A vacuum or residual pressure of 5 mm. was assumed. If the vacuum is even higher, the optimum height of the layer would be still smaller, just as, on the other hand, a lesser vacuum would increase the optimum height of the layer.

It is encouraging that the optimum height of the layer height appears to be so low that the above conditions of cooling do not yet play an important part and that the steam utilization with the optimum height of layer is thrice as high as at a considerably larger height of the layer.

In order now to develop from the above discussed canal-like unit a practical design, it must be folded, because a tube-type design would necessitate too great a length. It was found desirable to spiral-up the unit and arrange it in several layers one above the other. FIGS. 1 and 2 represent an apparatus which is designed in accordance with the present invention. The oil enters into the canal arrangement from within and flows towards the periphery and from there downwardly into the next stage. Below the oil is a steam chamber to distribute the steam plane along the lower face of the stream of oil. In the event of oil penetrating into the steam chamber in consequence of shut-down of operation, this chamber is provided with facilities to discharge the oil automatically. For this purpose, small tubes are arranged between the surface of the steam chamber and its deepest space, which tubes have a fine boring that opens in the upper surface. On account of the overpressure which the steam has in the chamber and which acts also on the surface of the oil layer, such oil is forced back to the surface. It is impossible therefore that any residues, which may be spoiled by too long exposure to steam treatament, be left in the chamber. The vapors are exhausted through a central stack which has its entrance slot in each individual chamber. These slots are so arranged that condensate drops which run down inside the vapor tube, cannot fall back into the chamber. As for the above reasons, With the specified low layer, the heat requirements are very low, it is sufficient to cover the radiation losses of the equipment by outside welded-on tubes, through which passes steam at a suitable temperature.

In FIG. 9 a complete plant is schematically illustrated. The oil flows through a heat exchanger, preheated, into a degasifier and then into a second heat exchanger stage. From there through a high pressure heated preheater into the top chamber of the deodorizer. After having passed through all chambers of the deodorizer, the oil is drawn off at bottom and, on its way to the finished oil tank, it passes through the heat exchangers in reverse direction. The flue gases of the furnace in which the high pressure steam is generated, are utilized to preheat the distillation steam. It is important that the possibly high preheating temperature be exactly regulated; to enable this, special control facilities known per se are provided. In order to prevent, as far as possible, entrainment of fatty acid traces in the vacuum equipment, the vapors are washed with circulating cool fatty acid. The condensating portion is drawn off at an overflow.

It will be understood that each of the elements described above or two or more together, may also find a useful ap plication in other types of deodorizing apparatus differing from the types described above.

While the invention has been illustrated and described as embodied in a steam deodorizing apparatus, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed and desired to be secured by Letters Patent is:

1. In an apparatus for deodorizing liquid material such as fats, oils and the like, in combination, chamber means; a substantially horizontal foraminous wall extending transversely through said chamber means and dividing the same into an upper treating chamber and a lower steam chamber; first feeding means for feeding material to be deodorized into said upper treating chamber so that the material forms a liquid bath above said foraminous wall; second feeding means for feeding steam at a predetermined pressure into said steam chamber so that the steam will pass through said foraminous wall and in finely divided form through said bath thereabove to deodorize the material forming the bath; and conduit means of small cross section extending from the upper surface of said foraminous wall to a lowermost portion of said steam chamber so that any liquid material passing in the absence of steam pressure in said steam chamber downwardly through said foraminous wall will be forced back through said conduit means into said upper treating chamber upon restoration of steam pressure in said steam chamber.

2. An apparatus for deodorizing liquid material such as fats, oils and the like comprising, in combination, a tower; a plurality of foraminous walls extending spaced from each other in longitudinal direction of said tower transversely therethrough; means cooperating with the underside of each foraminous wall and forming a steam chamber therewith; first feeding means for feeding the material to be treated into the space above the uppermost of said foraminous walls and from there downwardly and successively into the spaces above the consecutively following lower foraminous Walls so that the consecutively following lower foraminous walls so that the material to be treated will form a liquid bath above each foraminous wall while flowing in downward direction from the space above one foraminous wall to the space above the next lower foraminous wall; second feeding means for feeding steam at predetermined pressure into each steam chamber so that the steam will pass upwardly through each of said foraminous walls and in finely divided form through the liquid bath above each foraminous wall; steam withdrawal means maintained at a pressure smaller than said predetermined pressure and communicating with the space above each of said foraminous walls and above the level of the liquid bath formed above each foraminous wall for removing spent steam from said spaces and out of said tower, said withdrawal means pre venting flow of spent steam from any one of said spaces into any other space; and conduit means of small cross section extending from the upper surface of each of said foraminous walls to a lowermost portion of the steam chamber located beneath the respective foraminous wall so that any liquid material passing in the absence of steam pressure in said steam chambers downwardly through said foraminous walls will be forced through said conduit means out of the respective steam chamber into the space above the respective foraminous wall upon restoration of steam pressure in said steam chambers.

3. An apparatus for deodorizing liquid material such as fats, oils and the like comprising, in combination, a tower; a plurality of foraminous walls extending spaced from each other in longitudinal direction of said tower transversely therethrough; means cooperating with the underside of each foraminous wall and forming a steam chamber therewith; first feeding means for feeding the material to be treated into the space above the uppermost of said foraminous walls and from there downwardly and successively into the spaces above the consecutively following lower foraminous walls so that the material to be treated will form a liquid bath above each foraminous wall while flowing in downward direction from the space above one foraminous wall to the space above the next lower foraminous wall; second feeding means for feeding steam at predetermined pressure into each steam chamber so that the steam will pass upwardly through each of said foraminous walls and in finely divided form through the liquid bath above each foraminous wall; and steam withdrawal means including a plurality of superposed tubular members extending coaxially with said tower through the latter and each having an upper end portion of a cross section greater than the lower end portion thereof and the lower end portion of all but the lowermost of said tubular members being inserted into the upper end portion of the next lower tubular member so as to form an annular channel therewith respectively communicating with the spaces above the liquid bath forming above each of said foraminous walls for removing spent steam from said spaces and out of said tower, said withdrawal means being maintained at a pressure lower than said predetermined pressure and preventing flow of spent steam from any one of said spaces into any other space.

4. An apparatus for deodorizing liquid material such as fats, oils and the like comprising, in combination, a tower; a plurality of foraminous walls extending spaced from each other in longitudinal direction of said tower transversely therethrough; means cooperating with the underside of each foraminous wall and forming a steam chamber therewith; inlet means for feeding liquid material to be treated into a substantially central region of the space above the uppermost of said foraminous walls; a plurality of conduits each having an upper open end above one foraminous wall adjacent the outer periphery thereof and a lower open end closely adjacent the next lower foraminous wall and adjacent a central portion thereof so that the liquid material will flow from a peripheral region above one foraminous wall to a central region above the next lower foraminous wall while forming a liquid bath above each foraminous wall; an outlet conduit having an upper open end above and at a peripheral region of the lowermost of said foraminous walls and a lower end for feeding the liquid material after being deodorized out of said tower; feeding means for feeding steam at predetermined pressure into each steam chamber so that the steam will pass upwardly through each of said foraminous walls and in finely divided form through the liquid bath above each foraminous Wall; and steam withdrawal means including a plurality of superposed tubular members extending coaxially with said tower through the latter and each having an upper end portion of a cross section greater than the lower end portion thereof and the lower end portion of all but the lowermost of said tubular members being inserted into the upper end portion of the next lower tubular member so as to form an annular channel therewith respectively communicating with the spaces above the liquid bath forming above each of said foraminous walls for removing spent steam from said spaces and out of said tower, said withdrawal means being maintained at a pressure lower than said predetermined pressure and preventing flow of spent steam from any one of said spaces into any other space.

5. An apparatus for deodorizing liquid material such as fats, oils and the like comprising, in combination, a tower; a plurality of foraminous walls extending spaced from each other in longitudinal direction of said tower transversely therethrough; means cooperating with the underside of each foraminous wall and forming a steam chamber therewith; inlet means for feeding liquid material to be treated into a substantially central region of 1 l the space above the uppermost of said foraminous walls; a plurality of conduits each having an upper open end above one foraminous wall adjacent the outer periphery thereof and a lower open end closely adjacent the next lower foraminous wall and adjacent a central portion thereof so that the liquid material will flow from 21 peripheral region above one foraminous wall to a central region above the next lower foraminous wall while forming a liquid bath above each foraminous wall; an outlet conduit having an upper open end above and at a peripheral region of the lowermost of said foraminou-s walls and a lower end for feeding the liquid material after being deodorized out of said tower; guide wall means extending upwardly from each of said forarninous walls for guiding the liquid material entering the space above each foraminous wall at a central region thereof along a substantially spiral path toward the upper end of the conduit above said foraminous wall; feeding means for feeding steam at predetermined pressure into each steam chamber so that the steam will pass upwardly through each of said foraminous walls and in finely divided form through the liquid bath above each foraminous wall; and steam withdrawal means including a plurality of superposed tubular members extending coaxially with said tower through the latter and each having an upper end portion of a cross section greater than the lower end portion thereof and the lower end portion of all but the lowermost of said tubular members being inserted into the upper end portion of the next lower tubular member so as to form an annular channel therewith respectively communicating with the spaces above the liquid 12 bath forming above each of said foraminous walls for removing spent steam from said spaces and out of said tower, said withdrawal means being maintained at a pressure lower than said predetermined pressure and preventing flow of spent steam from any one of said spaces into any other space.

References Cited by the Examiner UNITED STATES PATENTS 803,394 10/05 Bogoiavlensky et a1. 261-114 1,328,259 1/20 Barbet 261-148 X 1,620,593 3/27 Brown 261-114 1,858,158 5/32 Laird. 2,500,934 3/50 Dean 261-114 2,619,336 11/52 Schilling 261-113 2,621,197 12/52 Thurman 260-428 2,662,756 12/53 McIlvaine 261-23 2,674,609 4/54 Beal et al. 260-428 2,722,505 11/55 Faulkner 202-46 2,743,915 5/56 Miller et al. 261-121 2,845,444 7/58 Thomson 260-428 FOREIGN PATENTS 406,429 11/43 Italy. 476,913 6/ 15 France.

GEORGE D. MITCHELL, Primary Examiner.

ARTHUR WINKELSTEIN, HEBERT L. MARTIN,

Examiners.

Claims

3. AN APPARATUS FOR DEODORIZING LIQUID MATERIAL SUCH AS FATS, OILS AND THE LIKE COMPRISING, IN COMBINATION, A TOWER; A PLURALITY OF FORAMINOUS WALLS EXTENDING SPACED FROM EACH OTHER IN LONGITUDINAL DIRECTION OF SAID TOWER TRANSVERSELY THERETHROUGH; MEANS COOPERATING WITH THE UNDERSIDE OF EACH FORAMINOUS WALL AND FORMING A STEAM CHAMBER THEREWITH; FIRST FEEDING MEANS FOR FEEDING THE MATERIAL TO BE TREATED INTO THE SPACE ABOVE THE UPPERMOST