May, 1923
475
INDUSTRIAL A N D ENGINEERING CHEMISTRY
industries, as well as molded articles of many special sizes and shapes.
INDUSTRIES CSING HARD-RUBBER EQUIPMENT A complete list of industries in which hard-rubber equipment is used would be too long to fall within the scope of this paper. A few installations will be briefly described which will serve as a general guide for those who may be interested. Hard rubber is used perhaps most extensively for handling hydrochloric acid of various strengths. Installations of this kind include apparatus for conveying the acid from tank cars to storage tanks. This is done in three ways-first, by blowing with compressed air from the car through hardrubber distributing lines; second, by pumping, using hardrubber pumps and distributing through hard-rubber piping; third, by siphoning through hard-rubber pipes to hard-rubber air lifts, which raise the acid to tanks for distribution. Hard-rubber pumps and piping are also used in connection with hydrochloric acid for the extraction of rare metals from their ores; in the manufacture of galvanized iron wire, and like products; by dye manufacturers, who find hard rubber excellent for conveying acid through various steps in the manufacture of dyes. Special parts, such as dipping baskets, air-agitator systems, solid hard rubber and hard-rubber-lined tanks, are used extensively by metal-etching concerns. This equipment is also suitable for dilute nitric acid, ferric chloride, and other solutions used for etching purposes. Various manufacturers use thousands of feet of hard-rubber pipe for siphon systems on nitric acid absorption towers. These systems are used from the first tower in the series through to the point where the nitric acid concentration exceeds 16” BB. One of the largest single uses of hard-rubber equipment is in the silk-dyeing industry for handling stannic chloride solutions used in weighting silk. Typical installations include mixing tanks for building up the tin content of the spent tin solutions and soaking tanks where the silk is soaked in the solution until the required weight has been taken on. I n the so-called “dynamiting” process, the tin solution in a continuous system is pumped by hard-rubber pumps into a constant level hard-rubber-lined tank, which in turn feeds hard-rubber-lined and covered centrifugal extractors which are filled with silk for weighting purposes. The solution passes through the silk fibers and is discharged into a hardrubber-lined collecting tank, from which it is again pumped t o the constant-level tank. The liquid is fed to the extractors for a definite period of time, this time being calculated t o produce a certain amount of extra weight per pound of raw silk. Hard rubber is used in large quantities in the manufacture of chlorine and hypochlorites by the electrolytic process, as piping for distribution of the chlorine gas from the cells and for collecting the hypochlorite liquor. Concerns engaged i n the manufacture of chlorine often furnish hard-rubber distributing lines with their chlorine containers. These lines convey the gas direct to bleaching processes in various industries, many of which use agitating systems forcing the gas through hard-rubber pipes drilled with small holes and immersed in tanks containing the material to be bleached. Chlorine control apparatus for use with flour and cottonbleaching processes is often of hard-rubber construction. Here hard-rubber towers, float balls, and various forms of special equipment are indispensable. An interesting development in the use of hard rubber is shown in the handling of plating solutions, many of which have a tendency not only to corrode, but also to form deposits on the surfaces of metallic containers. Hard-rubber goosenecks, electrode separators, and tanks are used in gen-
eral plating work, the tanks serving to reduce electrical leakage to a minimum, owing not only to the high insulating properties of hard rubber, but also because there are no pores in which the solution may crystallize as it does, for instance, in the cellular surfaces of wooden tanks. Many installations of hard-rubber equipment have been made in plants devoted to the manufacture of food products, where its resistance to corrosion and its nonporous and nonabsorbent properties make it ideal for handling such material as cider, fruit juices, vinegar, etc. Cider and vinegar plants use hard rubber very extensively, not only as pumps, piping, and fittings, but also in the form of special filtering apparatus, tilting vessels, and special distributors or sparges which are used in every vinegar generator. Condiment manufacturers use hard-rubber pipe, fittings, tanks, and special apparatus throughout their mixing and other processes, and even through to the point where the condiments are bottled. Very interesting results have been obtained recently in connection with experiments in the transportation of hydrochloric acid by means of hard-rubber-lined iron tanks mounted on tank cars. These experiments, while not yet altogether successful, show promise; and it seems probable that they may be carried on to a successful conclusion. Many other uses of hard-rubber equipment might be described, but those mentioned will serve to give a comprehensive idea of the wide range of usefulness of this unique material, and to show that it is worthy of consideration wherever the handling of corrosive substances prevents the use of the more common materials of chemical-equipment construction.
New H a v e n Registration The registration, by states, of those present at the New Haven meeting was as follows : 4 Oklahoma 2 Louisiana Arkansas 7 Maine 1 Omaha California 18 Pennsylvania Colorado 2 Maryland 108 Rhode Island 146 Massachusetts ConnecticLI t 25 Michigan 14 Texas Delaware 5 Vermont District of C,olumbia 6 3 Minnesota 7 Virginia 2 Missouri Georgia 1 Washington Illinois 38 Nebraska 13 West Virginia 7 New Jersey Indiana 265 Wisconsin 1 New York Iowa 4 Foreign 4 North Carolina Kansas 1 Ohio 56 Kentucky Guests 218 TOTAL REGISTRATION 1151
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Committee on Standardization of C u p r a m m o n i u m M e t h o d for Viscosity of Cellulose The AMERICANCHEMICALSOCIETY, through its Cellulose Division, has appointed a committee to standardize the determination of the viscosity of cuprammonium cellulose solutions as a control method. This committee is desirous of obtaining the cooperation of all individuals or firms who are interested in the cuprarnmonium method for viscosity of cellulose. ‘It is generally agreed that the method is of considerable importance in the cellulose industry, and no doubt there is considerable information available from widely scattered sources. The committee is anxious to obtain the assistance of anyone who is willing to cooperate o n this matter. Descriptions of methods now in use, together with comments as to possible means of improvement, or general discussion of the method and the results obtainable by it, will be welcomed by any member of the committee. The members of this committee are: I,. 0. LITTLETON, Massasoit Mfg. Co., Fall River, Mass. E. F. J. PUCKHABER,Stamsocott Co., Hopewell, Va. C. S. VENABLE,Viscose Co., Marcus Hook, Pa. W. 0. MITSCHERLING, 2018 Jefferson St., Wilmington, Del
