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CIATION ACHERS
WETTING AGENTS IN THE FIRE-FIGHTING INDUSTRY1 WILLIAM W. PARKER Arnold, Hoffman and Company, Inc., Providence, N o d e Island
SINCE WATER is the most universally used extinguishing agent for solid combustibles and is being recognized as an important agent for certain flammable liquids, the history of the fire-protection industry largely traces the development of equipment and techniques forits application. Water has had an important place in the extinguishment of fires for three major reasons. First, i t is a common material and is available practically anywhere, without cost. Second, it has great heat absorption capacity, enabling it to cool burning solids rapidly b e low their ignition temperatures. Third, and equally important, water is an efficient liquid. A liquid-extinguishing agent has important advantages in comparison with solid or gaseous types, not only in transportation and handling operations, but also in the actual extinguishment of solid combustibles. Fires occurring in solid combustibles are invariably in three dimensions and the extinguishing mediumwater--can normally be directed to a single plane. It has been emphasized repeatedly that water to cool and extinguish burning materials must reach the seat of combustion. If water were not a liquid, .capable of flowing and spreading around fire conflagrations to reach the seat of combustion, it would be a comparatively inefficient extinguishing agent. Another important function of water in practical fire fighting is its use to delay or prevent the ignition of combustibles. This function of water invariably is concurrent with actual extinguishment. For example, water used in extinguishing forest fires is partly applied to the burning material and partly applied to the unburned portion of the fire line. Water may also be utilized solely for this purpose for protecting exposures--for example, nearby houses. The same basic reasons outlined under extinguishment-namely, availability, cooling capacity, and liquid character'
isticsalso are valid when water is employed to delay or prevent ignition. The importance of the liquid characteristics of water in fire fighting had not been emphasized until wetting agents came into use. It has been demonstrated under practical fire conditions that water will not extinguish fires occurring in such materials as coal piles, stored grain, and baled textile fibers. In fact, one of the most serious problems in the control of forest fires is not the extinguishment of the spectacular surface lire, but the complete extinguishment of the ground fire. I n both deciduous and coniferous areas where there are sizable amounts of ground litter, water has not proved to be effective in completely extinguishing a iire line. Water under these conditions will rarely completely saturate and penetrate through the ground litter to mineral soil. The basic repsons for this failure may be found by analyzing the liquid and wetting properties of water. Therefore, standard operating procedures for forest fires, as outlined by the U. S. Forest Service and other organizations, have been to remove the combustible materhls and expose mineral soil by trenching. This procedure is both tedious and expensive. In many areas, because of personnel problems, it is virtually impossible to put this technique into practical use. Fundamentally, wetting and surface-active agents are empolyed to alter the liquid properties of water and enable it to flow more rapidly and efficiently and penetrate into combustible materials. Water so treated can also flow more readily around surfaces to protect exposures and penetrate more rapidly combustibles to prevent or delay their ignition. A one per cent aqueous solution of a good wetting agent will penetrate loose cottop batting 300 times as fast as un-treated water. Recent work also indicates that water treated with a properly formulated wetting agent will boil away from a surface more rapidly. It follows that if water boils away more rapidly it cools the surface faster and consequently speeds extinguishment.
Presented st the Ninth Summer Conference of the N.E.A.C.T., Wellesley College, Wellesley, Massachusetts, Aug. 21, 1947. 615
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JOURNAL OF CHEMICAL EDUCATION
Although the fundamental principles involved in the use of wetting agents in the fire protection industry are simple, practical problems involving equipment and techniques are nwherous. Although many surface-active and wetting agents' are commercially available, an e5cient formulation for this industry should have the following ehrtracteristics. I t should be readily soluble in water over a wide temperature range. It should form a water solution which has long-term stability and e5ciency. It should perform with all naturally occurring water supplies, and such water supplies may be acidic or alkaline or may contain high concentrations of inorganic salts. It should produce little change in nozzle or pump characteristics. It should be noncorrosive to the metals used in fire extinguishing equipment. It should incorporate a rust inhibitor to control the acceleration in the rate of rusting where premixed solutions are stored in ferrous tanks such as the booster tanks of fire trucks. Another major problem is the development of proper proportionating equipment in order that wetting agents may be introduced into line discharges with economy and accuracy. Comparable equipment has been developed for the introduction of mechanical foams. Normally, mechanical foam is used a t concentrations of 6 per cent by volume. Wetting agents are normally employed for fire extinguishment in concentratious ranging from 0.25 to 2 per cent by volume. The energy requirements for wetting agent proportionators, consequently, are lower than those for use with mechanical foams, and pressure drops across e5ciently designed proportionating equipment will be less. Finally, proposed wetting-agent formulations should be subjected to both laboratory firetestprograms and field-test programs under practical fire-fighting conditions. There is a critical need for an accurate fire test procedure for solid combuptibles. Controlled laboratory fire conditions have been attempted by the Danish investigator, F. Folke, as well as by T. R. Truax of the Forest Products Laboratory, U. S. Department of Agriculture, Madison, Wisconsin. Details of Mr. Truax's test procedure are reported in the October, 1939, issue of Fire Cmtrol Notes, U . S. Department of Agriculture. These tests used a small crib-type setup of wood. Important variables which must be controlled me: average moisture content of the fuel, fuel homogeneity, draft conditions, ignition source, and rate and method of extinguishing-agent application. In the tests conducted by Mr. Truax, the extingnishing agent, water, was applied manually through a small glass nozzle. This introduced a sizable humanerror factor. In both the tests conducted by the Factory M u t d Laboratories in Boston and by our organization much larger crib setup%were used. These cribs consisted of two-by-fours, 4 ft. in length, 4 pieces to a tier and from 8 to 11 tiers in height. The cribs weighed appcoximately 245 lb. To eliminate the human error in water application a 6xed spray nozzle system was employed. Even by meticulous attention to other details, it was only with
great d i c u l t y that reproducible results were obtained. The &st major investigations of the use of wetting agents for the extinguishment of solid combustibles and flammable liquids were conducted by the Factory Mutual Laboratories and by Arnold, Hoffman & Co., Inc. Fire tests were conducted by both organizat~ons with properly formulated wetting agents in concentrations varying from 0.5 to 2 per cent by volume. Some of these solutions extinguished the burning cribs three t i as fast as plain water. In other tests with kerosene extinguishment with water spray nozzles was effected in one-half the time and with one-half the nozzle pressure required for plain water. Rasults, however, with more volatile liquids whose h h points were less than 100°F. were of no practical value. Concurrently, with cooperation from fire department and forestry personnel, our company initiated a a major field testing program with a wetting agent formulation termed "Drench." After 18 months of field experienbe with fires of most types, including frame building and forest fires, the general theory and laboratory results had been substantiilly validated. In the Rhode Island area alone over 40 brush and forest fires have been extinguished with "Drench." It is the considered ,opinion of the operating personnel, including rangers of the Rhode Island Division of Forests & Parks, that the use of "Drench" on these fires bas resulted in faster fire-line extinguishment and completely eliminated the necessity for tedious overhaul, patrol, and trenching of the fire lines. "Drench" has been used in the booster tanks of the Providence Fire Department for several months with spectacular results. Chimney, partition, and upholstery fires bave been speedily extinguished with small quantities of treated water. Formerly, it was necesmry, because of lack of water penetration under such fire conditions, to use much larger quantities of water or to remove physically the combustible material. This.ageut ha8 also been widely used in rural fire fighting where water supplies are extremely limited. Such departments rely almost entirely in the initial stages of fire fighting upon tank water supplies. By treating a water supply with the wetting agent and by skillful application with modem fog nozzle equipment, they bave greatly increased the extinguishing capacity of their equipment. Other organizations have actively investigated this new field of fireprotection and additional products are available at the present time. , Although much test and field data are available which definitely indicate that the proper utilization of wetting and surface-active agents will greatly increase the extinguishing efficiency of water, additional research and development are needed both in the laboratory and in the field. More accurate laboratory test procedures should be devised. Reliable proportionating equipment must be developed and fire protection personnel trained in the theory, application techniques, and limitations of wetting agents to capitahe fully on this development.
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DECEMBER, 1947 0
Official B w i n e u
242nd Meeting, October 18, 1947. Laconia High School, Laconia, New Hampshire. The following program was given a t the 242nd meeting of the N.E.A.C.T.: Gree.tings, Rhoden B. Eddy, Superintendent of Schools, Laconia, New Hampshire; "Cobalt in a Nutritional Deficiency in Cattle,".Gordon P. Percival, University of New Hampshire; "Application Research in Industry," Frederic L. Matthews, Associate Director of Research, Merrimac Division, Monsanto Chemical Company; "Antibioticea review," John E. Little, University of Vermont. A short business meeting followed the luncheon. President Eldin V. Lynn has announced the appointment of the following committees:
Mr. Holden graduated Phi Beta Kappa from Bowdoin College in 1883. He served as sub-master of the Portland (Maine) High School from 1 W to 1886. For twenty-one years he taught in the Charlestown (Mass.) High School and for fifteen years at the High School of Commerce in Boston. He retired in 1923 and was eighty-nine years old a t the t i e of his death. Surviving are a wife, Mary, a son, Edward W. Holden of Concord, New Hapshire, and two daughters, Mrs. Francis Dow of Livermore Falls, Maine, and Mrs. Hector MacDonald of M e h e , Mass. C h a i m n , Necrology Committee. S. W ~ E HOYT, R
New Ildrmbers Robert C. Ericson, Mary Brooks Junior College, Bath, Maine g h School, Sprin&eld, Chemical Education Committee: Evelyn Murdock, Carroll C. Hall, Springfield k Illinois Chairman, Ralph E. Keirstead, Amasa F. W i s ton, Paul F. Stockwell, Benjamin R. Graves, Clarence D. L. Ropp, University of Bridgeport;Bridge port, Connecticut Harry Wiley, and David L. Davidson. Necrology Committee: S. Walter Hoyt, Chairman, Edna H. Shaver, Russell Sage College, Troy, New York Rev. Bernard A. Fiekers S. J., and Raymond S. 0 Schedule of Meeting, 1947-48 Tobey. December 13 : Haward University, Cambridge, MassaTenth Summer Conference Committee. As has been chusetts (Joint meeting with the Eastern Association announced previously, John A. Timm has been apof Physics Teachers and the New England Biology pointed C h a i m n . Carl P. Swinnerton has been a p Teachers Association) pointed Co-chairman. Those who already have been February 14: Rhode Island State College, Kingston, appointed are Ralph E. Keirstead, Elbert C. Weaver, Rhode Island Donald C. Gregg, Leallyn B. Glapp, and John C. Hogg. April 3: St. Thomas Seminttry, Bloomfield, ConnectiPlans are going forward to issue in 1948 a special cut booklet to commemorate the fiftieth anniversary of the May 8: Malden High School, Malden, Massachusetts foundiig of the Association. (Annual Meeting) 0
Necrology
Edward F. Holden, a charter member of the New England Association of Chemistry Teachers, died on March 5, a t his home, 32 Lake Avenue, Melrose, M w chusetts. In his passing the Association has undoubtedly lost the last of those who participated in the organization of this Association in 1898. A perusal of our old reports shows that Mr. Holden sewed as Treasurer from 1899 to 1906, then as Vice President for two years, 1907-08. He is listed as an Honorary Member in the Manual of 1910. After a decade of active participation in Association work, he became inactive due to a shift in his teaching program. He was also a noted authority on ornithology.
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Officen for 1947-48
Eldin V. Lynn, P r e d m t , Massachusetts College of Pharmacy, Boston 15, Massachusetts; Dorothy W. Giord, Secretary, Lincoln School, Providenee 6, Rhode Island; Lawrence H. Amundsen, Editor of the Report, University of Connecticut, Storrs, Connecticut; Millard W. Bosworth, Immediate Past President; John R. Suydam, Vice-President; C q o l l B. Gustafson, Treasurer; Leallyn B. Clapp, Southern Division Chaiman; Helen Crawley, Central Division Chairman; Jean V. Johnston, Western Division Chairman; Donald C. Chairman; Ralph E. KeirGregg, Northern %n stead, Curator; Elbert C. Weaver, Chairman Endowmend Fund; S. Walter Hoyt, Auditor.
