US2317915A - Bodying of drying oils - Google Patents

Description

" April 21, 1943. J. D. JEMNS 2,311,915

sonnue OF DRYING OILS Filed April 5, 1940 COOLER Patented Apr. 27, 1943 2,317,915 BODYING F DRYINGOILS John D. Jenkins, Forest Hills, Pa., asslgnor to Pittsburgh Plate Glass Company, Allegheny County, Pa., a corporation of Pennsylvania Application April 5, 1940, Serial No. 327,972

lClaims. ('01. 260407) The present invention relates to a process of heat-treating drying oils, such as are employed in the formulation of paints and varnishes and the like, and it has particular relation to the process of heat-treating such oils for purposes of increasing viscosity, and improving the rate of drying.

One object of the invention is to provide a drying oil which has a substantially faster drying rate than oils bodied by conventional methods.

A second object of the invention is to provide a process of bodying drying oils'which admits of removal and saving of free acids contained in the oil.

A third object of the invention is to provide a process of bodying drying oils by application of which the oil can be easily and quickly bodied to substantially any desired condition with a minimum of apparatus and expense.

A fourth object of the invention is' to provide a process of bodying oils which admits of bodying raw oils without break formation.

These and other objects of the invention will be apparent from consideration of the following specification and claims.

In the paint and varnish industry, oils of the nature of linseed oil, soy-bean oil, tung on and the like are employed as film-forming constituents. Before these oils are added to the paint or varnish composition they are often subjected to a process of heat-treatment termed bodying, which results in a substantial increase in the body or viscosity of the oil and also results in a product which dries more readily than the unbodied oil. The bodying process has heretofore involved the heating of the oil in a suitablekettle to a, temperature of several hundred degrees F.

for a period of several'hours. Such process is ity of the product is not always as great as migh be desired. Furthermore, theoils contained, or produced during the bodying operation, consid erable amounts of free fatty acids which were within themselves ,valuable for many purposes, such as the formation of artificlal'resins, plasticizers and other purposes, but under usual operating conditions,were allowed to waste. g

7 Also, by such process it is practically impossible to body raw oils because of separation of asludge termed breakFwhere the oil reaches atemperature of about 400 or 500 F. V 1

In accordance with the present invention a drying oil ofthe type of linseedoil, soy-bean oil,

or the like eitherin the raw or the refined state is subjectedto what might be termed a continuous bodying operation. involving the continuous feed of astream of. the, oil into a poolof'oil of appropriate size in a bodying kettle and simul-, taneously withdrawing corresponding amounts'of I s the bodied oils: As a fuIther feature the oil in the bodying kettle is continuously blown with an inert gas, such as carbon dioxide or flue gas, ,or

nitrogen in such manner that a proportion of the free fatty. acids contained in the oil are blownout and are recovered by condensation or .by other suitable treatment. 7

For a better understanding of theinvention reference maynow be had to the accompanying drawing in which the single figure is a diagrarn ma'tic'view of an appropriate e nbodimentv of apa paratus suitable for use in-the practice off the i V invention. 7

typically a batch operation and necessitates that.

each batch of oil b'e'carried through a particular cycle of heating and subsequent cooling. The

operation is comparatively slow'and' substantial amounts of apparatus are required. in the bodyfrom batch to batch and as a result the uniform- In .the drawing like numerals refer to like parts throughout. The apparatus, may include as a bodying kettle or container l0 formedof any v sultablemetal. This container'is provided with means pp ying heatthereto, for example;

it may be partially or completely enclosed or surrounded by theelectrical heating'coils-l l .and a ,lagging (not shown) for conserving-heat. Glyc- 7 I 'eride oilsfeither raw or partially; or completely refined are; supplied as feed oilto thepcontainer 10 throughg a conduit '12, whichgas ,shownin the drawing is'so formed at its outlet-extremity as to provide a diagonally downwardly-directed; lip

13 from which the oil continuously runs'as a solid; 1 quiescent stream; that flowsix'itothamainlbody.

. of 011 in the container Hlf vitha minimum "or tu' spl'ashing or turbulence. The container.-is ,'-also,l

' upwardly abouttubes33.

provided with power-driven agitator involving a shaft H having propellor blades i6, which are submerged in the oil.

The kettle or container I is formed with a slightly conical bottom H, which at its apex discharges into an outlet conduit 19 having a control valve 2|. In order accurately to control the level and therefore the quantity of oil in the container, it may be provided with a constant level overflow pipe, including a vertical portion 22, which may be open at its upper end and at as to insure that the oil flowing oil will havev been aflorded a substantial period of time for heat treatment in the'kettle.

As previously stated, substantial amounts of free acids exist in or are liberated in the drying oil as a result of the heat treatment. In order to prevent the ratio of these acids from becoming excessive it is desirable to blanket or to blow the oil with an inert gas, such as carbon dioxide or the like. This is readily accomplished by conducting the gas through a conduit 28 and discharging it adjacent to the bottom of the container. The inert gases escaping upwardly through the oil are dischargedthrough a drum 21, at the top of the container and passing outwardly through conduit 28 to a condenser apparatus comprising ashell' 29 of conventional design, involving drum sections and 32 at the top and bottom thereof respectively, and intermediate or connecting tubes 33' through which the vapors and the condensed oil flow downwardly.

The tubes may be cooled by any desired me-.

dium, but preferably the inert gas for the blowingoperation is used as a cooling medium and is thereby. preheated before introduction into the kettle. For this purpose the conduit 26' is connected at its upper end 36 to the shell 29 below drum'section 3| and receivesgas which is intro-,

duced by conduit 3! having an inlet to shell 23 above drum .32 and which is heated in its passage The cooled carbon dioxide from the drum 32 is dischargedthrough outlet conduit 38 and may be dried and otherwise treated preparatory to recycling to the apparatus. It may also be discharged to the atmosphere or employed for other purposes, if so desired. The free fatty acids con-' densed from the carbon dioxide in the tubes 33 are collected in the drum 32 and are discharged to storage through the'conduit 39.

Apparatus for cooling the bodied oil discharge from the container in and for preheating the oil a for inlet to the container through conduit I2 is indicated at ll. This apparatus includes a water cooler and'a heat exchange unit 43 intercom,

nected attheir'tops by :a conduit 44, whichin tumis-connected to the outlet conduit I! for the bodied oil. Valves and" upon: opposite sides of thelconduit i9 admit of selectively flowing the h'ot'but bodied oil either to the cooler |2or heat exchanger 43-or admits of dividing. the flow of oil to the two units inany desired manner. The

cooler and the heat :exchange unit are ofsub- 'stantially identical constructionv and include shells 48 having upper drums 49 and lowerdrurns- II, which are interconnected by tubes 52 in con-- ventional manner. The space about the tubes in the cooler 42 is filled with cooling medium, such as water, fed thereto through the conduit 53 and discharged at the top of the unit through conduit 54.

The heat exchanger 43 is employed to preheat the feed oil to appropriate temperature, e. g. about 400 to 500 F., which is accomplished by feeding the oil through conduit 59 to the lower portion of the space about the tubes 52, and drawing it off at the top of the same space through outlet El, which constitutes a continuation of the feed conduit [2. The cooled or partially cooled oil is received in the drums 5| and is discharged into the outlet conduit 6 l, which interconnects the drums. Conduits 62 and 63, connected to the conduits 6|, lead to a conduit 84 through which the bodied oil is discharged to storage.

It is'to be noted that by-pass conduits 66 and B1 are connected to conduit 6! intermediate of the unions or connections to the conduits 62 and 63. These by-pass conduits at their upper extremities are Joined to the conduit 44 upon opposite sides of the valves 46 and 41. Valves 68 and 69 are provided in the by-pass conduits and also valves H and 12 are disposed in the conduit 6| respectively between the by-pass conduits, the cooler 32 and the heat exchanger 43. A valve 13 is further disposed in conduit 6i between the two by-pass conduits. Finally valves 14 and 15 are disposed inthe conduits 62 and 63. It will be apparent that by appropriate manipulation of these various valves it is possible to discharge the whole of the bodied oii'either into the heat exchanger or the cooler, or the oil may be divided in any desired manner. Furthermore, the oil may be discharged from the heat exchanger and then passed through the cooler or vice versa,

depending upon operating conditions which it is desired to-obtain. It will be apparent also that.

.if desired, the oil may be by-pas sed through con- ,oil is allowed to stay in the bodying kettle for the requisite length of timerto obtain a satisfactory degree of bodying. This willdepend upon the temperature of the kettle and the nature of the oil itself. However, in general the temperature probably, will be around 600 F. The average time in the kettle will vary with'the degree of of bodying required and probably will be of the order of 1 to 10 hours. Oil introduced into the pool in kettle I0 is brought substantially instantaneously t'o bodying temperature.

The oil maybe drawn off, as it is bodied, through the discharge conduit vi 8 by merely opening the valve 2| to the requisite degree, or if preferred-the valve 2l may be closed and the oil allowed to discharge at the desired rate through throughconduit l9:to the water cooler 42 or the 7 heat exchanger 43 where it iscooled to the.de-

sired degree before 'passing to storage.

The feed of carbon dioxide or other inert gas into the kettle will depend upon theacidity desired in the final product. A certain degree of acidity is perhaps desirable and maybe obtained by increasing or decreasing the flow of inert gas, in order to blow away any excesses of the acids.

The following represent typical operating conditions for the bodying of linseed oil.

TABLE I.Lightly bodied linseed oils NOTE 1.-50 a by weight in acetone. Nora g-GS F., 65% relative humidity. Samples aged 20 hours belore testing.

The oils marked in the table as Refined were subjected to alkali refinement prior to the bodying operation. The oils marked "Raw were typical linseed oils without the alkali refinement treatment. The properties of these bodied oils may be compared with those of a typical alkali refined oil which was bodied by a conventional 7 These properties are tabulated batch process.

It is to be observed that the alkalirefined oil. when continuously bodied by the process herein disclosed, possesses. a substantially more rapid rate of drying than the corresponding oil bodied by conventional methods. For example, it ,will

be observed that infthe case of the conventional product the drying rateswere respectively 9.4 and hours dependent upon the drier which was added thereto. In contradistinction, the alkali refined oil, when bodied by the present process,

dried in periods of 5.7, 3.8, 4.8 and 2.9 hours, dependent upon the catalyst and the degree of bodying. The raw oil dried in periods of 6.7, 4.6, 5.3 and 2.9 hours, likewise dependent upon the catalyst and the degree orbodying to which.

it was subjected.

The oil when continuously bodied in accord ance with the present invention-is. subjected to substantially different conditions than exist in a conventional batch process. In a batch operation the oil is relatively slowly brought to bodying conditions and all of the oil is subjected'simultaneously to the same conditions and there isa tendency for all portions of it to go through the same reactions. The reactions of courseinclude various polymerizations ,in which monomeric glycerides are added together to forrndimers and subsequently dlmersare added-together or' V for equilibrium to be reached, a veryhigh percentage of the oil in the polymerization zone is Feed oil 7 Refined Raw Temperature of operation, F 603 608 Feed rate, gall/hr 10 10 Av. treatment time, hrs 2 2 CO1, wt. percent of feed oil 9. 7 6 F. A. distillate, percent of feed oil 1.3 Ratio wt. Col/wt. distillate 7. 5

Properties of produda Vis., cup at 25 0., sec '11 8 Color, Gardner 2. 5 Greenish Acid number..-.. 6. 7 8. Iodine value 134 136 Refractive index L 1. 4859 1.4852 griitinsohitem (N (rite 3.2).. I 4.0 Below 0 r g t me, rs. o

.3% Pb, 03% Mn 5. 7 6. 7 .0o% 00 3. s 4. 0

TABLE II.-Heam'ly bodied linseed oils Feed oil Refined Raw Temp. 0! operation, F 608 608 Feed rate, gaL/hr 2. 5 2. Ave. treatment time, hrs 8 7. 3 00; wt. percent of feed oil 38 33 F. A. distillate. peroentoi feed 0 8 l0 Ratio Co /distillate 4.8 3.3

Properties ofproducta Vis. M" cup'at 25 0., sec 210 195 Color, Gardner 4 5 Acid number 12.7 13. 9 Iodine value 116 Refractive index l. 4927 l. 4924 Crit. sol. temp, 0 0. (Note 1 39.6 37.7 Drying time, hrs. (Note 2):

3% Pb, .03% Mn 4. 8 5. 3

06% Co 2. 9 2. o

" formation is passed almost instantly and break in the condition of a relatively high polymer. The feed oil, which at any particular time is present in the reaction mass in only a relatively small amount, is ailorded an especially good opportunity for contact and reaction or addition to the higher-polymers and there is but little opportunity for contact of monomer with monomer. Therefore, it isto be expected that relatively small amounts of the dimer will be present in the bodied oil and proportionally there will be a relatively large amount of highly .polymerized material present.

applicants product. a l V Applicants process is'of particular value in the bodylng or raw. or unrefined drying oils, such as I linseed; soya bean, and the like, because'raw oils, when heated to a temperature of about 400 or 500 F. undergo break formation. 'A slime is produced that for most practical purposes can not be removed. However, in applicants process,

ii oil below "break" temperature is run into the I l pool ofbodying oil, the temperatureoi' "break" does not separate. The hotoil can then be bodied? A slightly bodied raw oil can be taken oil from the apparatus and then batch'bo'died,

if so desired. 1 v V The sudden heating seemsto result in fixation of the "break in the oil so that it does not separate during bodying. Presumably 'the'bodied raw oil still contains the break-forming constituents.

It is to be understood that the intermittent or pulsating feed of raw or refined oil into the body- I ing kettle and corresponding withdrawals o! bodied oil is contemplated. Likewise, it may sometimes be desirable to run oil, raw or refined, into a kettle which initially contains'only a small discharge is effected.

The forms of. the invention scop ortne'apn claims.

This perhaps tends to explainthe relatively high vrate of dryingof suificiently bodied,

herein-disclosed and described are to be understood merely.;as, exemplary and it will be'apparent' that numerous" .rnodlflcations may be made therein without de parture from thespirit of; the invention or the l What I claim is: a v

1. A process of bodying without "break formation raw drying oils from a class consisting of linseed and soy-bean oil, but containing breakform constituents, which process comprises continuously feeding unbodled raw drying oil into a pool of oil heated to the bodying temperature, substantially instantaneously admixing the feed oil with the oil of the .pool and correspondingly withdrawing the bodied oil,-the rate of feed and withdrawal of the: oil being so adjusted that the desired degree of bodying is obtained while the oil is in the heated pool, and bubbling into the oil in the pool an inert gaseous medium, in order to-remove free acids therefrom. *2. A process of bodying without break" formation raw drying oils from a class consisting of linseed and soy-bean, oil, which comprises bringingthe oil from a temperature below that of break formation to bodying temperature substantially instantaneously and then maintaining the oil at bodying temperature until a desired degree of bodying has been reached.

3. A process of bodying without break" formation raw, drying, glyceride oils from a class consisting of linseed and soy-bean oil and containing "break-forming constituents, which process comprises feeding the oil as a streaminto a pool of oil heated to 'bodying'temperature whereby to bring the feed oil substantially instantaneously to bodying temperature, and drawing'off bodied v oil as raw oil is fed in.

whereby to heat the feed oil substantially instantaneously to the bodying temperature, and correspondingly drawing oil oil from the pool, the pool being of such size that the oil is incompletely bodied while it is therein, and subsequently completing the bodying operation by further heating the oil in a batch operation.

5. A process of bodying without break formation drying oil from a class consisting of linseed and soy-bean oil and containing break-forming constituents, which process comprises running unbodied oil as a free falling stream into a pool of the oil heated to the bodying temperature, the temperature being maintained during the addition, then drawing ofif the oil after it has been bodied.

6. A process of bodying without "break formation raw drying oils from a class consisting of linseed and soy-bean oil, but containing breakforming constituents, which process comprises flowing the feed oil as a continuous stream into an agitated pool of oil at an elevated temperature under such conditions that the oil becomes substantially instantaneously heated to the temperature of the pool, said temperature being sumciently high to obviate ,break-forming tendencies in the oil, then subsequently bodying the oil.

7. A process of bodying a refined, drying, glyceride oil from a class consisting of linseed and soy-bean oil to obtain a product of drying properties superior to those of the same oil when batch bodied, which process comprises feeding the oil as a stream intoa pool of the oil heated to the bodying temperature" and substantially instantaneously mixing the feed oil with the heated oil in the pool, maintaining the oil in the pool until it is substantially bodied,a nd withdrawing bodied oil at approximately the rate at which it is fed in. V

. JOHN D. JENKINS.

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