The National Academies Press

Currently Skimming:

Pages 16-16

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.

From page 16... ... 244 F I R E R E S E A R C H The discharges between electrodes of certain low-boiling-point metals are known to be capable of igmting flammable gases at much lower levels of arc energy than wi th other metals, and i t has been observed that during the course of the discharge these low-boihng-pomt metals emit relatively large amounts of metal vapor and metal particles This current investigation was carried out in order to determine whether or not the small quantities of metal vapor or particles which are ejected into the surrounding gas during a discharge are capable of causing an igmtion I n one group of experiments, metal wires were exploded by discharging a capacitor bank through them and some of the explosion products were allowed to pass through a small hole into a chamber contaimng a flammable mixture of methane and air The results showed that all but the metals w i th the lower boihng pomts readily caused ignitions Schlieren photographs of the development of the igmtions indicated that, whereas individual particles of aluminum readily caused igmtions, individual particles of the other metals examined (Cd, Cu, Fe, Pb, Sn, W, and Zn) did not I n another group of experiments, small quantities of vapor and particles were produced by focussing the output of a ruby laser onto the flat surface of samples of both metals and nonmetals The amount of laser energy necessary to produce sufficient vapor to igmte a number of flammable atmospheres was determined for these matenals, and i t was found that this amount increased considerably as the boiling point of the material decreased I t was concluded that the ease with which arc discharges between low-boihng-point metals cause igmtions was not due to the ignition of the flammable atmosphere by the metal vapor and particles emitted during the discharge Weinberg, F . Read the entire page →

From page 16...

... 244 F I R E R E S E A R C H The discharges between electrodes of certain low-boiling-point metals are known to be capable of igmting flammable gases at much lower levels of arc energy than wi th other metals, and i t has been observed that during the course of the discharge these low-boihng-pomt metals emit relatively large amounts of metal vapor and metal particles This current investigation was carried out in order to determine whether or not the small quantities of metal vapor or particles which are ejected into the surrounding gas during a discharge are capable of causing an igmtion I n one group of experiments, metal wires were exploded by discharging a capacitor bank through them and some of the explosion products were allowed to pass through a small hole into a chamber contaimng a flammable mixture of methane and air The results showed that all but the metals w i th the lower boihng pomts readily caused ignitions Schlieren photographs of the development of the igmtions indicated that, whereas individual particles of aluminum readily caused igmtions, individual particles of the other metals examined (Cd, Cu, Fe, Pb, Sn, W, and Zn) did not I n another group of experiments, small quantities of vapor and particles were produced by focussing the output of a ruby laser onto the flat surface of samples of both metals and nonmetals The amount of laser energy necessary to produce sufficient vapor to igmte a number of flammable atmospheres was determined for these matenals, and i t was found that this amount increased considerably as the boiling point of the material decreased I t was concluded that the ease with which arc discharges between low-boihng-point metals cause igmtions was not due to the ignition of the flammable atmosphere by the metal vapor and particles emitted during the discharge Weinberg, F .

Read the entire page →

Key Terms

← Previous Chapter Skim

Next Chapter Skim →

This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More information on Chapter Skim is available.