Accession Number : AD0282936

Title :   AN EVALUATION OF CERTAIN ASPECTS OF MULTIPURPOSE POWDER FIRE EXTINGUISHING AGENTS

Descriptive Note : Interim rept.

Corporate Author : NAVAL RESEARCH LAB WASHINGTON D C

Personal Author(s) : NEILL,R.R. ; TUVE,R.L.

Report Date : 16 JUL 1962

Pagination or Media Count : 18

Abstract : Class A fires of the wooden crib type were modeled on a small scale and correlated with Underwriters' Laboratories tests of multipurpose dry-chemical fire extinguishing powders. Satisfactory agreement was obtained compared with water extinguishment on the same models. Woodfire extinguishment efficiency of two of the products closely approached that of water. Multipurpose powders applied with proper technique, are effective in the extinguishment of rubbertire fires, but a solution of wetting agent in water shows measurable advantages in efficiency on this type of fire. Class B fires of the tankconfined gasoline fuel type bicarbonate dry chemical powders show a 30% weight efficiency superiority in the same tests. Low-temperature (-40 F) operation of the various candidate devices with their powders shows efficient discharge. Fully satisfactory extinguishment can be expected on Class A, Class B, or mixed-classsing a piped dry chemical system are extinguished with equal amounts of both sodium bicarbonate type powders and multipurpose powders. Potassium bicarbonate dry chemical powders show a 30% weight efficiency superiority in the same tests. Low-temperature (-40 F) operation of the various candidate devices with their powders shows efficient discharge. Fully satisfactory extinguishment can be expected on Class A, Class B, or mixed-class fires at these temperatures provided there is no leakage of extinguisher pressure. Since Class C fires may be considered as mixed-class types, with the added hazard of possible energized electrical circuits, this class of fire was not modeled. (Author)

Descriptors :   *FIRE EXTINGUISHERS, *FIRES, *POWDERS, AMMONIUM COMPOUNDS, CARBONATES, COMBUSTION, FOAM, MOBILE, MODEL TESTS, PHOSPHATES, POTASSIUM COMPOUNDS, SODIUM COMPOUNDS, TIRES, WOOD

Distribution Statement : APPROVED FOR PUBLIC RELEASE