William J. Parker

The phi meter: A simple, fuel‐independent instrument for monitoring combustion equivalence ratio

An instrument has been developed to monitor the equivalence ratio in combustion systems. It is based on a novel oxygen consumption measuring method. The instrument does not require knowledge of the chemical composition of the process being monitored. Both gaseous and solid (soot) products of incomplete combustion are successfully handled. The device is relatively compact and can be developed for moderate cost and portable use.

8 – Fire Hazard Analysis

This chapter illustrates the upholstered furniture fire problem with respect to fire hazard analysis. The fundamental hazard to life that a person can encounter during the course of a furniture fire is the exposure to a lethal or incapacitating atmosphere. This consists of four elements: high concentrations of toxic gases, high levels of thermal radiation, high temperature air, and smoke obscuration that can interfere with the ability to escape. The relative importance of these hazard elements varies according to the type of fire: well ventilated, propagating fire; under-ventilated propagating fire; non-propagating fire; and smoldering fire. The chapter also discusses therole of other factors such as the distance from the fire, smoke and toxic gases, and toxic potency differences among commercial materials.

Surface Temperature Measurement In A Fire Environment Using An Infrared Pyrometer

If a surface temperature measurement were added to a heat release rate test apparatus like the standard ICAL, the net heat flux could be determined. Then the heat of gasification could be calculated for use in the CFD fire models. This paper describes the measurements of the surface temperature history of specimens in the ICAL using an infrared pyrometer operating in the 8 to 10 micron wavelength band. These temperatures were verified by simultaneous measurements with a bare 0.127 mm diameter type K thermocouple pulled tight against the surface of the specimen. As the burning surface receded during the test, the tension, and therefore the surface contact of the thermocouple, was maintained by weights attached to the thermocouple lead wires which passed through two small holes to the back of the specimen. Because of the strong vibrational bands common to organic polymers, there was very good agreement with the thermocouple for these materials when the spectral emissivity setting of the pyrometer was equal to 1.0. There was essentially no effect of the flames or smoke from the specimens in the ICAL on the temperatures indicated by the pyrometer.

6 – Upholstered Item Design Engineering

This chapter discusses fire safety design, considering the effects of upholstered item construction and materials separately for smoldering (cigarette) and flaming ignition. The chapter presents a table in which it shows the heats of combustion and other thermal properties of fiber materials from which upholstery fabrics are made. The heats of combustion and other thermal properties of fiber materials from which upholstery fabrics are made are also shown in a table. The table shows the fibers that are thermoplastic, that is, melt, and which are char formers. Otherwise, these properties seem to relate only in a few cases to the burning behavior in composite form. The relatively low cigarette ignition resistance of polypropylene (olefin) could be related to its low density (affecting its effectiveness as a heat sink) and melting point (exposing the padding). Similarly, polypropylene and nylon have relatively high heats of combustion which may contribute to their high HRRs found in many test series.

4 – Ignition Sources

Publisher Summary This chapter discusses the technical details of ignition sources that have caused upholstery fires or have been used in fire tests for upholstered items. Paul and Christian, and Murrell published general papers on ignition sources. The first mentioned paper includes 1984 UK statistics for involvement of various ignition sources in fire incidents, and data on the duration, heat of combustion, heat flux, and other parameters of a large number of ignition sources such as matches, lighters, electric light bulbs, arcs and sparks, various arrangements of folded and crumpled newspaper, torches, etc. The paper provides useful background for the three gas flame and four wood crib choices in BS 5852 and detailed comparisons of the characteristics and the effects on a variety of substrates of small butane and propane diffusion flames, methenamine pills, and matches. However, because there were relatively few ignitions with the BS source, no comparative rankings among these ignition sources could be established. The characteristics of many such ignition sources are discussed in the chapter.

Impact of air velocity on ignition in the Intermediate Scale Calorimeter (ICAL)

Higher surface temperatures were required for ignition in the Intermediate Scale Calorimeter than in the Cone Calorimeter. Air velocity measurements were made in front of calcium silicate and particleboard specimens in the Intermediate Scale Calorimeter and temperature measurements were carried out on their exposed surfaces. The higher ignition temperature in the Intermediate Scale Calorimeter was the result of the high induced upward air velocity due to the large specimen size (1.0 m by 1.0 m). This caused the flame to blow off. A higher surface temperature was needed to produce a downward flame spread rate sufficient to overcome the upward air velocity. To counteract this effect, a horizontal projection plate extending 100 mm out from the bottom edge of the specimen was installed. This created an eddy, causing a downward air velocity near the surface at the bottom of the specimen The igniter was a hot wire across the width of the specimen at a height of 100 mm. The flame quickly spread down from the igniter to the bottom edge and attached there. Under these conditions the temperature required for ignition of particleboard in the Intermediate Scale Calorimeter was less than it was in the Cone Calorimeter.