US2423214A - Foam prevention - Google Patents

Description

Patente July 11, 1194? F PREVENTION Sidney D. Wells, Combined Locks, Wis., assignor to The Institute of Paper Chemistry, a corporation of Wisconsin No Drawing. Application March 16, 1944, Serial No. 526,823

1 Claim. l

The invention relates to foam prevention and is of particular value in preventing foam from developing on the surface of stock which is fed to paper-making equipment.

When making various types of paper, for example, printing papers, the stock of which contains a substantial percentage of groundwood, considerable difficulty is encountered by reason of the development of foam on the surface of the stock feed in various parts of the equipment due to conditions of operation which frequently are necessarily inherent in the paper-making process or operation and cannot be conveniently changed in view of practical operating requirements.

The object of the present invention is to provide a treatment or method of operation which may be applied to existing paper-making operations without the necessity of making any material change in the standard make-up or furnish, or in the operating technique.

In general, it may be said that the invention contemplates that there shall be added or fed to the stock or paper-making furnish a relatively small quantity of a water-oil emulsion of special type. Preferably this emulsion is fed to the stock continuously at a point somewhere between the beater and the slice. When a condition develops which will, and does, result in the formation of foam, the feed of anti-foaming agent is commenced until the foam is destroyed, and thereafter, usually the feed of anti-foaming agent may be reduced considerably in view of the fact that it is not necessary to feed as much anti-foaming material to prevent formation of foam as is required to destroy foam which has already developed on the stock.

The anti-foaming agent which has been found to be of value in this connection is an aqueous emulsion comprising a siccative oil, preferably a vegetable oil such as linseed oil, China-wood oil, or other vegetable oil, which oil preferably has been partially oxidized or subjected to a boiling treatment, which siccative oil is diluted with a mobile inert solvent such as kerosene or similar mineral oil which is not too volatile. The emulsion is stabilized by the use of any suitable stabilizing agent known to be of value in stabilizin a water-oil emulsion of the composition above referred to. For example, one stabilizing agent 'Which has been successfully used is a material marketed under the brand name Stanolind No. 250, which material is derived from the acid oil resulting from oil refining. It contains the sulfuric acid compounds of components found in natural petroleum and is called mahogany soap.

In preparing a supply of the de-foaming agent above referred to, the stabilizin agent is preferably first dissolved in the inert solvent, and then the resulting solution is thoroughly mixed with the siccative oil. Then this combined mixture is diluted with about twice the weight of water and thoroughly mixed and emulsified by vigorous agitation with a high speed propeller type mixer, for example a mixer of the type known on the market as a Lightning mixer.

After the emulsion has been formed in the above manner, it may be kept for several days without danger of settling and is of such consistency that it can be fed drop by drop to the stock feed.

Specific example Boiled linseed oil gals 15 Kerosene ls-.. 28 Stanolind No. 250 lbs 48 Water als These materials are all combined according to the practice previously outlined.

In the case of a paper machine making four tons of groundwood base printing paper per hour, the most troublesome foam which develops due to any normal condition can usually be broken by feeding 3 drops of this emulsion per second to the riilies between the fan pump and the screens. After the foam has been broken and has disappeared, the feed of emulsion may be considerably reduced, for example, to 1 drop per second, so that a twenty-four hour run will require only a very few gallons of the emulsion in order to obtain satisfactory results.

The scope of the invention should be determined by reference to the appended claim.

I claim:

An aqueous emulsion the components of which are kerosene, boiled linseed oil, mahogany soap,

3 and Water in the proportions of 28 gallons of kerosene, 15 gallons of boiled linseed oil, 48 pounds of mahogany soap, and 100 gallons of Water, prepared for use as an agent for preventing foam on the stock feed of a paper-making, machine.

SIDNEY D. WELLS.

REFERENCES CITED Number UNITED STATES PATENTS Name Date Bradshaw Nov. 24, 1931 Heckel May 2, 1933 Mathias June 26, 1934 Weik Dec. 10, 1935 Fritz Dec. 8, 1942 Fritz et a1 Apr. 25, 1944 Evans et a1 Apr. 17, 1945 FOREIGN PATENTS Country Date Number Great Britain May 23, 1935