US2363924A

US2363924A - Purifying waters with stabilized emulsion

Info

Publication number: US2363924A
Application number: US284126A
Authority: US
Inventors: Wayne L Denman
Original assignee: Dearborn Chemical Co
Current assignee: Dearborn Chemical Co
Priority date: 1939-07-12
Filing date: 1939-07-12
Publication date: 1944-11-28
Anticipated expiration: 1961-11-28

Description

Patented Nov. 28, 1944 ascents rune warsits wrrn sranmmn EMULSION Wayne L. Denman, Berwyn, Ill., assignor to Dearborn Qhemical Company, Chicago, 111., a corporation of Illinois No Drawing. Application July 12, 1939, Serial No. 284,126

16 Claims (01. zit-23) The present invention relates to the treatment of waters or aqueous baths having present ingredients inducing foaming.

In the more specific form of the invention, it is I proposed to treat waters of the above character including wayside boiler feed waters with astabiilized substantially permanent anti-foam emuls on.

While it has hitherto been proposed to add an anti-foam composition to the water present in the wayside treater, this procedure has been impossible due to the tendency of the anti-foam composition to separate during the period that the wayside water may stand in the wayside treater prior to it being introduced into the engine. As a result of this dimculty, the following procedure has been in vogue on the railroads up to the present time. When the locomotive leaves the terminal, the engine crew is provided with a certain amount of an anti-foam composition, which is carried in a pail, usually in the cab of the locomotive. When the train stops to take n water, the engineer or the fireman, and usually the latter, takes a certain amount of anti-foam composition, which experience has indicated is the proper amount, introduces the same into a small pail, adds a little water and mixes the anti-foam composition with the water with the aid of a steam hose from the engine. The resultant anti-foam slurry is then thrown into the locomotive tender and is ultimately led to the engine through the injector or through the pump. The above procedure, prior to the present invention, has been the only one possible even in the cases where wayside treaters have been installed for the purpose or feeding totally or partially softened water to the engine.

It is clear from the above, that up tothe present time all of the anti-foam compositions that have been added to the wayside treater havebeen so .unstable as to. allow the ingredients of the composition to separate or precipitate from the composition to such a degree as to render the antifoam composition inefiective.

In accordance with the present invention, the 45 wayside boiler feed water is provided with a stable anti-foam composition which is capable of being" dispersed or suspended therein for a relatively long period of time. Such a stable antiioam dispersion may be termed a substanti permanent dispersion. It is desired to point out that, the anti-foam agent of the composition may be a liquid or a solid. If the anti-foam agent to be dispersed is a liquid. dispersion is eiiected preferably, although not necessarily, at room temperature. On the other hand, if the active antifoam agent is a solid, preferably the dispersion is effected at an elevated temperature, that is, a temperature somewhat above room temperature, which is usually around 70 F. If the solid antifoam agent is dissolved in a suitable solvent or colloidally suspended. in the solvent, so that the suspension approaches, in its characteristics, a solution, then the dispersion may be carried out at room temperatures. In any of the above cases, dispersion at room 9 temperature is desirable, since the resulting emulsion is usually more highly dispersed. The criterion is that that temperature should be used which will give the best dispersion. 7

Since, in the anti-foam composition of the present inventiomthe anti-foam agent is kept permanently dispersed, the composition may be prepared at a central plant, and transported to its point of use, or the composition may be placed in storage and used as desired. From a storage standpoint the present invention is highly advantageous, as it enables the anti-foam composition-to be kept indefinitely without destroying the dispersion of the anti-foam agent. I It has been discovered that if an anti-foam agent is highly dispersed by any or the usual mediums, as, for example, by passage through a colloid mill or a viscolizer, or through a homogeniser, that such dispersion can be maintained by providing a medium functioning to prevent coalescence. A suitable medium for accomplishing the above purpose is formed by mixing a tannin compound or a tannin-containing material, as, for example, a tanning extract, with a boroncontaining material, the latter functioning to se up or stiffen the tanning extract. While the present invention in its broadest iorm is directed to maintaining a permanent disperslon of the active anti-foam agent present in an anti-roam composition, irrespective of the concntration oi the active anti-foam agent, the invention is of particular value in maintaining the anti-foam agent permanently dispersed where the concentration of the anti-foam agent in the antifoam composition is relatively high. For example, in an anti-foam composition having present a castor oil emulsion, the stability of the emulsion decreases rapidly as the oilcontent increases. In other words, with increase of oil concentration in the anti-foam composition, the conditions are favorable for increased oil globule size. The decrease in degree of dispersion with increasing oil content may be ascribed to the fact that theparticles or oil globules collide with one another more frequently at the higher concentrations.

It may be stated that the stability of a dispersion of the character herein set forth depends primarily upon two facts: First, the presence of protective colloids capable of being adsorbed on each of the individual particles or oil globules of the dispersed phase and, secondly, the maintenance of a continuous phase of such viscosity as to substantially prevent or greatly reduce the collisions between the dispersed particles or oil globules. The increased viscosity of the continm ous phase also tends to prevent rising or sinking of the dispersed oil globules and, of course.

a whether the globules rise or sink depends upon the relative densities of the. dispersed and continuous phases respectively. The stifiened or viscous medium of the present invention permits the anti-foam agent, as, for example, 'castor oil globules, globules of chlorinated stearone, or hydrolized chlorinated stearone, or equivalent globules or particles, to be held more or less rigid to thereby prevent coalescence of the globules or particles, while the anti-foam composition is being transported or is in storage.

It has also been discovered that the stifiening or setting of theanti-foam composition may be varied by controlling the amount of boron-containing compound present. While the setting characteristics of the anti-foam composition will vary somewhat with the type of tannin-containing material used and the particular boron-containing material used, as a rule, it is desirable that the amount of boron-containing material present varies between about one-eighth of one per cent to approximately five per cent. For example, when adding to 'an anti-foam material ordinary borax in the amount of two per cent, the composition is sufllciently firm to support a persons weight. Stated difierently, the composition was hard, and when removed from the container in which it was shipped, it was in the form of rather friable pieces. This degree of hardness for most purposes is not desirable in a product which is to be transported in a shipping drum or container, due, first, tothe difficulty in removing the set anti-foam composition from the shipping drum or container and, secondly, because of the difllculty in dissolving the hard set material in water or any. other liquid, at the point of consumption.

escapee fore, includes a tannin-containing material, as,

for example, tannin extract, a colloid having protective action supplemental to the protective colloid action of the tannin extract, a boron-containing material and an active anti-foam agent. The first three ingredients are preterably and usually mutually soluble and form the continuous phase of the anti-foam composition, the dispersed phase being formed by the anti-foam agent, such as castor oil or the equivalents thereof.

While such an anti-foam composition may be used and fair results obtained, it is desired to have present an agent adapted to prevent the clumping together of the particles of the antifoam agent and inhibit the formation of portions of the anti-foam composition devoid of dispersed material. It may be stated that if an anti-foam composition is prepared, as set forth, there will be produced, immediately after treatment'in a viscolizer 0r colloid mill, a highly dispersed composition. However, on standing the individual particles of the anti-foam agent, as, for example, the castor oil globules, exert a tendency to clump together, and, further, the composition displays a tendency towards the formation of a clear layer of extract at the bottom of the container,- said layer being devoid of dispersed materials. While this tendency of the globules to clump together is disadvantageous in some respects, the composition, even without the presence of an anti-clumping agent, gives fair results. Preferably, however, it is desirable that the anti-foam composition contain an anti-clumping agent of the character herein set forth. Various materials may be used to inhibit the tendency of the particles of the anti-foam agent to clump together. discovered that the tendency towards liquidseparation at the bottom of the container and the tendency of the particles or globules of the active anti-foam agent to clump or cluster together can be substantially reduced and practically eliminated by the incorporation in the anti-foam composition of a soluble phosphate. The best results have been obtained by using an alkali phosphate,

I as, for example, trisodium phosphate. The tri- It is exceedingly diflicult to state what consistency orstiflfness should be maintained in the anti-foam-composition. Broadly, the set or the sodium phosphate reduces the acidity of the antifoam composition and tends to form a buffered found that satisfactor results are obtained when the trisodiumphosphate is used in amounts vary- I ing between 10% to 12%, based on the weight of the entire anti-foam composition. While in the table herein set forth, showing suitable examples oi anti-foam compositions embodying the present It has been invention, trisodium phosphate has been set forth as the anti-clumping agent, it is to be understood that equivalent materials may be used and that the amount of anti-clumping. agent can be substantially varied from none at all to a maximum greater than set forth.

It may be stated that the use of about 12% trisodium phosphate in the anti-foam composition increases the pH of the anti-foam material from approximately 4.0 to a pH of 6.9. While an increase of pH is characteristic of the use of trisodium phosphate as the anti-clumping agent, such increase in acidity is not a concomitant of all anti-clumping agents. Instead of using trisodium phosphate a mixture of disodium phosphate and sodium hydroxide, and/or a mixture of monosodium phosphate and sodium hydroxide, and/or a mixture of phosphoric acid and sodium hydroxide may be used. These can be used in approximately the same percentages as the trisodium phosphate. Of course, instead of using a mixture of disodium phosphate and sodium hydroxide there may be used a mixture of disodium phosphate and sodium hydroxide entity and the monosodium phosphate and sodium hydroxide entity. Similarly any one of the anti-clumping mixtures herein set forth may be mixed with one or more of the herein disclosed anti-clumping mixtures.

It may be stated that in the best embodiment of the present invention the diameter of the average globule of the active anti-foam agent of the resent invention will approximate one-half micron. While, as stated, in the best embodiment of the present invention the diameter of the average particle or globule of the active anti-foam agent should approximate one-half micron, the size of the particle or globule may somewhat depart therefrom and still come within the spirit of the present invention. In other words, the active anti-foam agent may be somewhat greater in size than one-half micron. Functionally, the size of the particle or globule should be such as to enable the anti-foam ingredient to remain in suspension in the wayside treater water for a period of at least twenty-four to forty-eight hours.

In accordance with the present invention there is added to the wayside boiler feed water an antifoam composition containing a highly dispersed anti-foam agent. Heretofore, as pointed out, it has been impossible to treat wayside water with an anti-foam composition, because the anti-foam agent separated from the treatment composition, during the period that the wayside water stood in the wayside treater, prior to the water being introduced into the engine. In accordance with the present invention this difliculty has been obviated. The tendency of the anti-foam composition of the present invention to stay in suspension and remain dispersed is primarily due to two facts; first, the extreme fineness of the material as obtained by the use of the colloid mill or equivalent agency, and, second, the presence of protective colloids and peptizing agents that prevent or assist in preventing the coalescence of the extremely finely divided anti-foam particles or globules. While the anti-foam composition of the present invention may be added directly to the wayside treater, the more usual practice is to mix the anti-foam composition in a chemical mixing tank with water prior to'its introduction into the wayside treater.

The following table sets forth anti-foam compositions suitable for carrying out the present invention:

Chlorinated stearone 16. 0 Hydrolized chlorinated steerone l5. 8

16.0 e. 0 6.0 4. 0 British gum.. (i. 0 5. 9 Trlsodium phosphate. 11. 5 11.5 11.5 11. 5 l1. 5 ll. 0 Borax .5 .5 .5 .5 .5 1.0 Tannin extract. 62. 25 57. 25 64. 25 64.25 58. 66. 25 Added Water 1. 8. 1. 50 1. 50 1. 50 1. 50 Fungicide .25 .25 .25 .25 .25 .25 T 100.00 100. 00 100. 00 1100. 00 100. 00 |I100. (B

Table I--Continued Mixture number 7 8 l 9 l0 11 I 12 Castor oil 16.0 4. 0 8. 0 15. 5 I 20. 0 25.0 Corn starch 6.0 Tapioca starch 6. 0 Dextrin 12. 0 12. 0 12.0 12. 0 12. 0 Trlsodium phosphate. 11.87 11. 0 l1. 0 ll. 5 10.0 10. 0 Borax 13 l. 0 l. 0 5 2. 0 5.0 Tannin extract 58 25 70. 25 66. 25 58. 54. 25 46. 25 .50 1. 50 l. 50 1. 50 1. 50 1. 50

The typical compositions set forth in the above table are passed through a colloid mill or equivalent apparatus and the composition is allowed to set.

Referring to the above table, it is to be noted that the amount of the anti-foam agent may vary over quite a large range. The percentages set forth are merely illustrative and the antifoam agent may be present in the composition in amounts less than 4%, or in amounts greater than 25%. It may be stated that any of the prior art anti-foam agents may be used, such as degras, cottonseed oil, sperm oil, or even paraflin, ketones, their substitution products and derivatives; and aliphatic amines, their substitution products and derivatives, including halogen substituted and aromatic substituted amines and ketones and hydroxy substituted ketones, said materials being substantially insoluble in water and containing eleven (11) or more carbon atoms.

The supplementary protective colloid, as, for example, dextrine 0r starch, is preferably present in an amount around 12%, taken on the weight of the anti-foam composition. However, it is to be understood that this is merely the preferred percentage and that the percentage of the supplementary protective colloid may vary and may be as low as 4%, and, in addition, may be considerably greater than 12 In the above illustrative examples, the borax which has been set forth as typical of a boroncontaining compound, may be replaced by boric acid, any water-soluble boron compound, including the water-soluble borates, or any water insoluble or slightly water-soluble boron compound, including the borates. Any material which is capable of producing a borate ion when dissolved in water and functioningin combination with a tannin to produce a set tannin-boron entity may be used to carry out the present invention. More specifically, suitable compounds are the alkali borates, including sodium meta-borate, potassium tetra-borate, lithium borate and the like. The alkali borates, ammonium borate and boric acid are examples of water soluble boron-containing compounds, which function very satisfactorily in carrying out the present invention. The slightly soluble borates also function to produce a set tannin. boron-containing entity. Compositions have been made, using boron trioxide, that is, the anhydride of ortho, meta and tetra borieacid, calcium borate, and magnesium borate. Each of these materials was mixed with a portion of tannin extract, that is usualcommercial tannin extract. These materials were also mixed with a tannin extract which had been neutralized with 12% of trisodrul n phosphate. The pH of the unneutralized tannin extract was 4.2, while the pH of the neutralized tannin extract was 6.7. Each of the above materials, when added to the hen-- tralized and unneutralized tannin extract, produced a stiifening'action. In other words, the mixture of boron-containing material and tannin extract stiffened or set up. The stiffening action was the most pronounced in the case of boric acid and the least pronounced in the case of magnesium borate. The order of stiffness induced in the tannin extract boron-containing entity is as follows: boric acid, boron trioxide, borax, calcium borate and magnesium borate. There was not much difierence between the stiffening effect produced by boric acid, boron trioxide and borax. There was considerable difference in the stiffness induced by calcium borate 'and mognesium borate.

Magnesium borate is insoluble in hot and cold water, while calcium borate is soluble in water to the extent of .4 part in 100 parts of water at both 30' C. and 90 C. (Van Nostrands Chemical Annual 1934). The results obtained indicate that the magnesium borate, which is substantially insoluble in hot and cold water, exerted a, stiffening effect which was considerably greater than that of calcium borate, which is soluble in water to a very minor extent. It is probable that the tannin extract exerts an action on the insoluble borates, causing the borate or borate ion to enter into the solution. Therefore, stated broadly, any boron-containing material may .be-used, whether it is water soluble or substantially water insoluble, provided, in the presence of tannin, some of the borate or the borate ions enter into such a combination as to cause the tannin borate to set. Any of the organic borates may be used having an organic radical which will not deleteriously affect the anti-foam composition. In this connection, it may be pointed out that the important thing is .to providea negative boron or borate ion, the positive ion being unessentlal to the functioning of the invention and, therefore, is referred to by way of illustration, rather than by way of limitation.

The active anti-foam agent, such as castor 011,--

or its equivalent, may be dispersed in any of the above tannin boron-containing entities, with or without a supplementary protective colloid and/ or an anti-clumping agent, and the resulting mixture is'preferably continuously passed through" a colloid mill, or' a homogeniser, and then to the shipping drum or the container. Preferably the time of passage of the anti-foam composition through the mill is-onlya matter of a few sec- .onds. It is desired to pointout that considerable heat may be developed as the anti-foam composition passes through the colloid mill or equivalent apparatus.

leave the mill at'a temperature of F. or F.

The setting action of the anti-foam composition is due to the reaction between the tannin, or tannin-containing compound, of the anti-foam composition and the boron-containing constituent thereof, as, for example, borax. The setting action is a time reaction which is somewhat retarded by the temperature increase in the mill. Usually the set of the anti-foam composition is not complete until approximately twenty-four to forty-eight hours after the composition has left the colloid mill. As stated, the time of setting is a function of the time reaction between the tannin-containing constituent and the boroncontaining constituent. The dissipation of the heat developed in the mill, due to the friction, does play a, minor part in the speed with which the ultimate consistency is attained. It may be pointed out that where sufficient borax is used to produce a fairly hard consistency of the final product, the setting action takes place while the material is quite hot, and the dissipation of the heat plays little part in determining the ultimate consistency of the anti-foam composition. Where the desired consistency is relatively thin, and where the amount of borax to obtain this consistency is correspondingly less, the dissipation of the heat developed in the colloid mill plays a somewhat greater part in determining the consistency of the final product. It is desired to point out that inasmuch as the percentage of borate is relatively small and-the percentageof tannin in the tannin-containing solution is relatively high, and, further, in view of the fact that the anti-foam composition takes usually from twenty-four to forty-eight hours to reach the consistency which is thereafter permanently maintained that substantially all of the boroncontaining compound, as for example the borate, that is capable of reacting with the tannin does react during the setting period. The important point is that the borate and tannin should be present in such proportions as to'produce a stillened anti-foam composition from the initially liquid composition, the stiffened composition in the preferred form of the invention being a paste, although as indicated, other consistencies may be employed as long as the particles or globules of the anti-foam ingredient are prevented from coalescing. It may be pointed out that the consistency which is commercially used is chosen due I cient amount of water to form a pasty product,

but this is. distinctly different from contacting a liquid solution of a boron-containing composition, such as borax with a liquid tannin-containing constituent, such as tannin, and allowing the paste to form in the presence ofan excess of water due to action between the borax and the tannin.

- It is preferred that the composition containing the active anti-foam agent, together with, the

stifiening agent, be passed through the colloid mill, while the material is cold, that is, around room temperature of about 70 F. By the above procedure there is obtained a composition caryear.

with about live to ten gallons of water.

rying an anti-foam agent, such as castor oil, in

a highly dispersed state and the radii of the oil globules is greatly decreased. With a decrease in the radii of the oil globules, the degree of dispersion becomes relatively high and the tannin boron-containing entity keeps the globules or particles of the anti-foam agent in an isolated state and prevents their agglomeration and subsequent settling.

Since the anti-foam composition of the present invention contains a tannin extract, and preferably a carbohydrate protective colloid, there is a tendency for the composition to develop molds and/or fungus growths rather rapidly, said growths tending to form tough skins on the surface of the material. In order to prevent the growth of molds and fungi the composition prefbeen maintained in containers without any noticeable changes under varying conditions of weather. and climate, for a period exceeding one forth may be added to the wayside treater water in dosages of approximately one pound per thousand gallons of feed water to one pound per twenty thousand gallons of feed water. The most common dosage is in the neighborhood of one pound of the present anti-foam composition for four thousand gallons of water to one pound per eightthousand gallons ofwater. The amount which may be added to the wayside treater is strictly illustrative and is not to 'be taken by way of limitation.- Obviously, the amount of anti- Typical anti-foam compositions herein set foam composition which is added to the water in the wayside treater will depend'upon the characteristics of the water, and undoubtedly the character of the active anti-foam agent present in the composition will influence the amount of the composition, which is added to the water present in the wayside treater. A previously pointed out, it is preferable to mix the anti-foam composition with a limited amount of water or other aqueous medium, in a chemical mixing tank, prior to its introduction into the wayside treater. Usually one pound of the anti-foam composition is mixed in the chemical mixing tank The above is merely illustrative and it is not to b taken by way of limitation.

'It is desired to point out that the stabilized anti-foam emulsion may be used for the purpose of treating the wayside water, after the latter iected to an additional anti-foam treatment because of the inconvenience of carrying this material on the locomotive itself. With the present invention, it becomes possible to treat water. with a stabilized permanent anti-foam emulsion following the treatment of the water with lime-soda,

a zeolite, or any other type of external treatment even though the foaming tendency of the water is not very great.

Where it is necessary to treat the wayside water with lime and soda ash, it has been the usual practice to have the lime and soda ash mixed in the chemical treating tank and to pump this mixture from the treating tank into the wayside treater and into the bulk of the water by means of a chemical pump. In accordance with the present invention, in combining the anti-ioam treatment as a finishing treatment for water that has been treated by the soda-lime method, it is preferred that the lime-soda ash be mixed in one tank and that a separate chemical tank be providedin which the anti-foam material of the present invention is diluted with a relatively small amount of water sufllcient to allow the material to be pumped. Thereafter the aqueous suspension of the anti-foam material is pumped simultaneously with or subsequently to th material from the lime-soda chemical tank into the wayside treater. This insures that there is no chemical action between the lime-soda mixture and the anti-foam material.

The present invention is particularly adapted for the treatment of water or aqueous baths containing alkaline compounds. or compounds or constituents inducing alkalinity. It is particularly adapted for the treatment of boiler waters containing "excess alkalinity. By this term, it is intended to define water in which the substances inducing alkalinity in the water are present in excess of that capable of combining with or existing in combination with th calcium and magnesium ions, salts or their chemical equivalents present in the water.

However, the invention is applicable for the treatment of waters of any kind, including boiler feed waters in which the alkalinity is present in a quantity just suflicient to combine with the ca1- cium and magnesium ions, salts or their equivalents contained in the waters, or is insumcient to completely combine with said calcium and magnesium ions. The invention is particularly applicable to waters containing sodium or potassium alkalinity, that is, water in which the sodium or potassium alkalies, or their equivalents, and particularly sodium or potassium hydroxides, carbonates or bicarbonates. exist in excess of calcium and magnesium ions, or are present in suflicient quantity to combine completely with said ingredients.

Excess alkalinity :may exist naturally in the water or may be derived from zeolite treatment of the water or may be derived in other ways. The invention may-be applied to raw waters, either hard or soft, and beneficial results obtained. Waters which have been softened by phosphates, sodium silicates, or other alkaline treatment, may be treated in accordance with the anti-foam composition of the present invention.

The following table sets forth the chemical characteristics 01' a number of feed waters which have been treated in wayside treaters. In said table the chemical compounds present in the water are expressed in grains per United States gallon. The anti-foam composition may be added in the wayside treater to raw water or to water that has been given a preliminary treatment, as, for example, internally treated, zeolite treated, or treated by the lime and soda process. The table shows the chemical characteristics of the raw water and the water which has been given a-prellminary treatment, but before the anti-few composition of the present invention has been added to the wayside treater for the purpose of, preventing foaming of the feed water in the boiler. The term "boiler feed water" as herein used, is intended to cover any water which is used for c the generation of steam.

Table I! Iron and Calcium Treatment alumi- Calcium water used Smca num as carbonate oxides Raw water .44 v 7.73 greeted grater" 3g 04 lg. 32

23W W8 8I A Treated water" l. 12 .40 w Raw water. Internal 79 7.39 Treated water; Lime and .39 .04

- soda ash. Do do .58 .02 2.45 Raw water"... 14 .02 .40 4.46

20 Table II-Continued Cel- Magnewater Treatment cium slum Alkali used sulbicar- Mes sulphates phste bonate Raw water 4.99 8.69 l. 80 Treated water s. as 46 e. 26 Raw water".-. )Zeome 1.21 3.09 1.58 Treated water" l9 6. 60 l. 58 Raw water".-. Internal..- 17.62 ll. 17 7.90 80 Treated waten- Lime and 3.04 1.75 99. 19

- soda ash. 4

Do do l.% 6.28 75. 78 Raw water 1.0!? 1.60 .42

Table Ill-C, ontinued Treat- Alkali Alkali Or- Sus- Water ment chloniganio pended hydroxused rides trates matter matter ides Raw water. Treated we- InternaL.

ten 2.38 Trace- Raw water" 1 92 Tr gated ws- Ze0lite r. Raw water-. InternaL. 7.14 Trace. 1.63 3:60 Treated wa- Lime and 14.96 Trace- .70 1.40

ter. s 8])1 d s as Tigted wsdo 2.38 Trace- 1.05 .43 Raw water .34 Trace- Trace.

While the tannin borate time reaction product has been specifically set forth as an example of the set phase, it is obvious that at least a part of the present invention resides in the broad concept of providing such a set phase for the dispersed particles of the anti-foam agent to prevent the latter from coalescing. Once given this concept, the skilled worker in the art will provide other set mediums,- and, therefore, the invention is not to be considered as limited to a tannin borate set phase which will function as set forth, but is broadly directed to any set phase which will function for the purpose set forth. This aspect of the invention is broadly stated and broadly claimed.

While the tannin extract herein set forth is preferably a blend of chestnut oakand quebracho extracts, along with other forms of tannin, it is obvious that other tannin extracts. or blends thereof may be used in carryingout the present invention. The tannin extract used inthe preparation of the herein disclosed anti-foam.composition contains about 40% solids and of this about 25% to 30% is actually a tannin or a tannin comaqueous tannin extracts may be used. 76

2,sea,e24

The term "continuous phase" is used in the specification and the claims in its customary sense; namely, to denote the dispersion phase. In other words, a continuous phase is a. medium in which the particles of the anti-foam agent are dispersed. When the continuous phase starts to congeal, it begins to set, and by the term set continuous phase" it is intended in the specification and claims .to cover any continuous phase congealed sufliciently to prevent the particles of the anti-f0 agent from coalescing when said composition is stored or shipped.

The expression treating the bath with an antifoam composition is used in some of the-claims in the sense that the anti-foam agent is present in the bath. In some of the claims it has been indicated that the set continuous phase is formed by the time reaction of a plurality of water soluble components. Of course, these components only have to be soluble to a limited degree. As herein-indicated, calcium borate may be used, this having a limited solubility. The expression above used is intended to include components having limited solubility. I

What is claimed is: i

1. LA stable anti-foam composition for treating an aqueous bath to inhibit foaming therein, comprising a set water-soluble continuous phase having colloidally dispersed therethrough particles of an anti-foam agent in a finely divided non-coalesced state, said water-soluble continuous phase preventing the particles of the anti-foam agent from coalescing, said set water-soluble continuous phase including the reaction product formed by a time chemical reaction between a tannin extract. and a boron-containing compound having a water-soluble boron ion in the presence of an excess of aqueous liquid, said reaction product having the property of stiffening in the presence of said excess of aqueous liquid, the time of the reaction in the presence of said aqueous liquid being such as to stifien the reaction product of the tannin extract and the boron-containing compound to at least the state or a paste, and a. protective colloid to assist in preventing the finely divided particles of the anti-foam agent from coalescing when the set continuous phase dissolves in the presence of an aqueous bath.

2. A stable anti-foam composition for treating an aqueous bath to inhibit foaming" therein, comprising a set water-soluble continuous phase having colloidally dispersed therethrough 4 to 25% of an anti-foam agent, the particles thereof being in .a finely divided non-coalesced state, said water-soluble continuous phase preventing the particles of the-anti-foam agent from coalescing, said set water-soluble continuous phase including the reaction product formed by a time chemical reaction between a. tannin extract and a boroncontaining compound having a water-soluble boron ion in the presence of an excess of aqueous liquid, said reaction product having the property of stiifening in the presence of said excess of aqueous liquid, the time of .the reaction in the presence of said aqueous liquid being such as to stiii'en the reaction product of the tannin extract and the boron-containing compound to at least the state of a paste, and a protective colloidto assist in preventing the finely divided particles of the anti-foam agent from coalescing when the set continuous phase dissolves in the presence of an aqueous bath. 7

3. A. stable anti-foam composition in paste form for treating an aqueous bath to inhibit foaming therein, comprising a set water-soluble continuous phase having colloidally dispersed therethrough particles of an anti-foam agent in a finely divided non-coalesced state, said watersoluble set continuous phase which prevents the particles of the anti-foam agent from coalescing including the reaction product formed by a time chemical reaction between a tannin extract and a boron-containing compound having a watersoluble boron ion in the presence of an excess of aqueous liquid, said reaction product having the property of stifiening in the presence of said excess of aqueous liquid, the time of the reaction in the presence of said aqueous liquid being such as to stiffen the reaction product of the tannin extract and the boron-containing compound to at least the state of a paste; and a carbohydrate protective colloid to assist in preventing the finely divided particles of the anti-foam agent from coalescing when the set continuous phase dis solves in the presence of an aqueous bath.

4. A stable anti-foam composition in paste form for treating an aqueous bath to inhibit foaming therein, comprising a set water-soluble continuous phase having colloidally dispersed therethrough particles 01 an anti-foam agent in a finely divided non-coalesced state, said watersoluble set continuous phase which prevents the particles of the anti-foam agent from coalescing including the reaction product formed by a time chemical reaction between a tannin extract and a boron-containing compound having a watersoluble boron ion in the presence of an excess of aqueous liquid, said reaction product having the property of stiffening in the presence of said excess of aqueous liquid, the time of the reaction in the presence of said aqueous liquid being such as to stifien the reaction product of the tannin extract and the boron-containing compound to at least the state of a paste; a protective colloid to assist in preventing the finely divided particles of the anti-foam agent from coalescing when the set continuous phase dissolves in the presence of an aqueous bath, and an agent to prevent the clustering together of the dispersed particles of the anti-foam agent on the addition of the composition to an aqueous bath.

5. A stable anti-foam composition inpaste form for treating an aqueous bath to inhibit foaming therein, comprising a set water-soluble continuous phase having colloidally dispersed therethrough particles of an anti-foam agent in a finely divided non-coalesced state, and watersoluble set continuous phase which prevents the particles of the anti-foam agent from coalescing including the reaction product formed by a time chemical reaction between a tannin extract and a boron-containing compound having a watersoluble boron ion in the presence of an excess of aqueous liquid, said reaction product having the property of stifiening in the presence of said excess of aqueous liquid, the time of the reaction in the presence of said aqueous liquid being such as to stiiTen the reaction product of the tannin extract and the boron-containing compound to set continuous phase dissolves in the presence of an aqueous bath, and a water-soluble phosphate acting to prevent the dispersed particles of the anti-foam agent from clustering together on the addition of the composition to an aqueous bath.

6 A stable anti foam composition for treating an aqueous bath to inhibit foaming therein, comprising a set water-soluble continuous phase having colloidally dispersed therethrough 4 to 25% of an anti-foam agent, the particles thereof being in a finely divided non-coalesced state, said water-soluble set continuous phase which prevents the particles of the anti-foam agent from 0021-- lescing including the reaction product formed by a time chemical reaction between a tannin extract and a small amount of a boron-containing compound having a water-soluble boron ion in the presence of an excess of aqueous liquid, said reaction product having the property of stiifening in the presence of said excess of aqueous liquid, the time of the reaction in the presence of said aqueous liquid being such as to stiffen the reaction product of the tannin extract and the boron-containing compound to at least the state of a paste; and 4 to 12% of a protective colloid to assist in preventing the finely divided particles of the anti-foam agent from coalescing when the set continuous phase dissolves in the presence of an aqueous bath.

'7. The method of inhibiting foaming in an aqueous bath having present ingredients inducing foaming, comprising treating the bath with an anti-foam composition containing the reaction product formed by a time chemical reaction between a tannin extract and a boron-containing compound having a water-soluble boron ion in the presence of an excess of aqueous liquid, said reaction product having the property of stiffening in said excess of aqueous liquid, the time of the reaction in the presence of said aqueous liquid being such as to stiifen the reaction product of the tanning extract and the boron-containing compound to at least the state of a paste, said reaction product functioning as the continuous phase, particles of a colloidally dispersed antiioam agent, and a protective colloid, said set continuous phase preventing the dispersed particles of anti-foam agent from coalescing prior to solution of the former, and the protective colloid assisting in preventing the finely divided particles of anti-foam agent from coalescing when the set continuous phase dissolves in the aqueous bath and liberates the finely divided particles of antifoam agent from their fixed state.

8. The method of inhibiting foaming in boiler feed water having ingredients present inducing foaming comprising treating the water while it is in a wayside treater with an anti-foam composition containing a set water-soluble continuous phase formed by a time reaction product between a tannin extract and a boron-containing compound having a water-soluble boron ,ion in the presence of an excess of aqueous liquid, said reaction product having the property of stifiening in the presence of said excess of aqueous liquid, the time of the reaction in the presence of said aqueous liquid being such as to stifien the reaction pro-duct of the tannin extract and the boroncontaining compound to at least the state of a paste, and having colloidally dispersed therein particles of an anti-foam agent and a protective colloid, said set continuous phase preventing the dispersed particles of anti-foam agent from coalescing prior to solution of the former, and the protective colloid assisting in preventing thefinely divided particles of anti-foam agent from coalescing when the set continuous phase dissolves in the aqueous bath and liberates the finely divided particles of anti-foam agent from their fixed state.

9. The method of inhibiting foaming in way.- side treater boiler feed water having ingredients present inducing foaming comprising introducing into water a relatively small amount of an antifoam composition containing a set water-soluble continuous phase formed by a time reaction product between a tannin extract and a boron-com taming compound having a water-soluble boron ion in the presence of an excess of aqueous liquid,

, said reaction product having the property of stiffening in the presence of said excess of aqueous liquid, the time of the reaction in the presence of said aqueous liquid being such as to stifien the reaction product of the tannin extract and the boron-containing compound to at least the state of a paste, and having colloidally dispersed therein particles of an anti-foam agent, and a protective colloid, said set continuous phase preventing the dispersed particles of anti-foam agent from coalescing prior to the solution of the continuous phase, and the protective colloid assisting in preventing the finely divided particles of anti-foam agent from coalescing when the set continuous phase dissolves insaid small amount of water, and liberates the finely divided particles of anti-foam agent from their fixed state, and treating the, wayside treater water with the resulting product containing said finely divided particles of anti-foam agent.

10. The method of inhibiting foaming in wayside treater boiler feed water having ingredients present inducing foaming comprising introducing into water a relatively small amount of an antifoam composition containing a set water-soluble continuous phase formed by a time reaction product between a tannin extract and a boron-containing compound having a water-soluble boron ion in the presence of an excess of aqueous liquid, said reactidn product having the property of stifiening in the presence of said excess of aqueous liquid, the time of the reaction in the presence of said aqueous liquid being such as to stiffen the reaction product of the tannin extract and the boron-containing compound to at least the state of a paste, and therein particles of an antifoam agent, a protective colloid, and an agent to prevent the clustering together of the dispersed particles of the anti-foam agent when the composition assumes a liquid state, said set continuous phase preventing the dispersed particles of anti-foam agent from coalescing prior to the solution of the continuous phase, and the protective colloid assisting in preventing theflnely divided particles of anti-foam agent from coalescing when the set continuous phase dissolves in said small amount of water, and liberates the finely divided particles of anti-foam agent from their fixed state, and treating the wayside treater water with the resulting product containing said finely divided particles of anti-foam agent.

11. The method of inhibiting foaming in wayside treater boiler feed water having ingredients present inducing foaming, comprising introducing into water a relatively small amount of set watersoluble continuous phase containing the reaction product formed by a time chemical reaction between a tannin extract and a boron-containing compound having a water-soluble boron ion in the presence of an excess of aqueous liquid, said reaction product having the property of stiffening in the presence of said excess of aqueous liquid, the time of the reaction in the presence of said aqueous liquid being such as to stiffen the reaction product of the tannin exract and the boron-containing compound to at least the state of a paste; said set continuous phase having colloidallydispersed therein particles of .an antiioam agent, and a protective colloid, said set said aqueous liquid beingsuch as to stiffen the.

aseaeaa continuous phase preventing the dispersed particles of anti-foam agent from coalescing prior to the solution of the continuous phase, and the protective colloid assisting in preventing the finely divided particles of anti-foam agent from coalescing when the set continuous phase dissolves in said small amount of water, and liberates the finely divided particles of anti-foam agent from their fixed state, and treating the wayside treater water with the resulting product containing said finely divided particles of anti-foam agent.

12. The method of inhibiting foaming in wayside treater boiler feed water having ingredients present inducing foaming comprising introducing into water a relatively small amount of an antiioam composition containing a set water-soluble continuous phase formed by a time reaction product between a tanninextract and a boroncontaining compound having a water-soluble boron ion in the presence of an excess of aqueous liquid, said reaction product having the property of stiffening in the presence of said excess of aqueous liquid, the time of the reaction in the presence of said aqueous liquid being such as to stiflen the reaction product of the tannin extract and the boron-containing compound to at least the state of a paste, and therein particles of an anti-foam agent, a protective colloid including a carbohydrate, said set continuous phase preventing the dispersed particles of anti-foam agent from coalescing prior to the solution of the continuous phase, and the protective colloid assisting in preventing the finely divided particles of anti-foam agent from coalescing when the set continuous phase dissolves in said small amount of water, and liberates the finely divided particles of anti-foam agent from their fixed state, and treating the wayside treater water with the resulting product containing said finely divided particles of anti-foam agent.

13. The method of producing an anti-foam composition comprising oolloidally dispersing an anti-foam agent through a mixture of an aqueous tannin extract and a boron-containing ma terial having a water-soluble boron ion, said' compounds being capable of reactingin the presence of an excess of aqueous liquid to produce a stiffened chemical reaction product, passing the resulting mixture through a colloidal mill to finely divide the anti-foam agent, and setting and stiffening the resulting mass by a time chemical reaction of said water-soluble compounds in the presence of said excess of aqueous liquid, the time of the reaction in the presence of said aqueous liquid being such as to stiffen the chemical reaction product to at least the state of a paste;

whereby the finely divided particles of anti-foam agent are prevented from coalescing.

14. The method of producing an anti-foam composition, comprising oolloidally dispersing an anti-foam agent through a mixture of an aqueous tannin extract and a boron-containing material having a water-soluble boron ion, said compounds being capable of reacting in the presence of an excess of the aqueous liquid to produce a stifiened chemical reaction product, treating the resulting mass to finely divide the oolloidally dispersed particles of the anti-foam agent, and setting and stiflening the resulting mass by a time chemical reaction of said water-soluble compounds in the presence of said excess of aqueous liquid, the time of reaction in the presence of chemical reaction product to at least the state of a paste, whereby the finely divided particles of the anti-foam agent are prevented from coalescing.

15. A stable anti-foam composition for treating an aqueous bath to inhibit foaming therein, comprising a set water-soluble continuous phase having dispersed therethrough particles of an anti-foam agent in a finely divided non-coalesced state, said water-soluble set continuous phase which prevents the particles of the anti-foam agent from coalescing including the stifiened time chemical reaction product formed in the presence of excess aqueous liquid by the chemical re: action between an aqueous solution of a tannin extract, together with about A; of 1% to approximately 5% of a boron-containing compound having a water-soluble boron ion, said reaction product having the property of stiffening in the presence of said excess of aqueous liquid, the time of the reaction in the presence of said aqueous liquid being such as to stiffen the reaction product of the aqueous tannin extract and the boroncontaining compound to at least the state of a paste, and a protective colloid to assist in preventing the flnely divided particles of the antifoam agent from coalescing when the set continuous phase of the anti-foam composition dissolves in the presence of an aqueous bath.

16. A stable anti-foam composition for treating an aqueous bath to inhibit foaming therein, comprising a set water-soluble continuous phase having dispersed therethrough particles of an antifoam agent in a finely divided non-coalesced state, said water-soluble set continuous phase which prevents the particles of the anti-foam agent from coalescing including the stiffened time chemical reaction product formed in the presence of excess aqueous liquid by the chemical reaction between an aqueous solution of a tannin extract, together with about 5% of 1-% to approximately 5% of a boron-containing compound having a water-soluble borate ion, said reaction prodnot having the property of stifiening in the presence of said excess of aqueous liquid, the time of the reaction in the presence of said aqueous liquid being such as to stifien the reaction product of the aqueous tannin extract and the boroncontaining compound to at least the state'of a paste, and a protective colloid to assist in preventing the flnely divided particles of the antifoam agent from coalescing when the set continuous phase of the anti-foam composition dissolves in the presence of an aqueous bath.

' WAYNE L. DENMAN.