Development of the cone calorimeter—A bench-scale heat release rate apparatus based on oxygen consumption

A new bench-scale rate of heat release calorimeter utilizing the oxygen consumption principle has been developed for use in fire testing and research. Specimens may be of uniform or composite construction and may be tested in a horizontal, face-up orientation, or, for those which do not melt, in a vertical orientation. An external irradiance of zero to over 100 kW m^?2 may be imposed by means of a temperature-controlled radiant heater. The rate of heat release is determined by measuring combustion product gas flow and oxygen depletion, while the mass loss is also recorded simultaneously. The instrument has been designed to be capable of higher accuracy than existing instruments and yet to be simple to operate and moderate in construction cost. The instrument is thermed a ‘cone calorimeter’ because of the geometric arrangement of the electric heater.     

A closed-form approximation for post-flashover compartment fire temperatures

A method is developed, suitable for design purposes, which allows approximate post-flashover fire temperatures to be calculated without the use of computer codes. This method may be used for thermoplastic pool fires, wood crib fires, and other fires of known fuel release rate. Both ventilation-limited and fuel rate-limited fires are treated. Results typically agree to within 3% of exact computer code solutions.     

Flame lengths under ceilings

The evaluation of hazards from developing room fires often requires a knowledge of flame lengths developed by burning objects. Procedures for estimating flame lengths have been available only for vertical plume fires, where there is no flame impingement on the room ceiling. Calculational procedures are developed for approximate calculation of flame lengths when part of the flame flow is along the ceiling. Four common geometries are treated: unbounded ceiling, plume near corner, plume in corner and one-directional corridor spread. Ceiling flame lengths are calculated by use of the assumption that the total air entrained up to the flame tip is the same for ceiling flow as for the free fire. Comparison with limited experimental data suggests potential for prediction in full-scale room fires.     

Temperature measurement in fire test furnaces

A study of errors associated with temperature measurement in fire endurance test furnaces has shown that conventionally used thermocouples are subject to large time constant errors in the first 20 minutes of a standard test.     

Standardization of formats and presentation of fire data—the FDMS

Effective exchange of fire test data, even within a single laboratory, has been difficult due to the multiple, and often incompatible, data formats and hardware. This issue has been addressed by a careful study of user needs, leading to the development of a series of standard formats whereby fire test data could easily be exchanged among users. These formats have been made practical by the development of a computer program—the Fire Data Management System (FDMS)—and pertinent hardware standards. The system includes the most commonly used of modern-day fire test methods, but also has provisions for future extension to other tests of interest.     

A simplified characterization of upholstered furniture heat release rates

The technology for measuring uphostered furniture heat release rates was established with the development of the furniture calorimeter. Analysis of a large number of tests in the furniture calorimeter has now demonstrated that for most specimens a good approximation to the rate of heat release as a function of time may take the form of a triangle. Methods of generating such curves, suitable for fire protection engineering hazard assessment purposes, have been developed.     

Concepts for fire protection of passenger rail transportation vehicles: Past,present, and future

Recent advances in passenger rail transportation, fire test methods, and hazard analysis necessitate re-examination of requirements for fire safety. Several studies have indicated nearly random ability of current bench-scale tests to predicts actual fire behavior. Fire safety in any application, including transportation, requires a multi-faceted approach. The effects of vehicle design, material selection, detection and suppression systems, and emergency egress and their interaction, on the overall fire safety of the passenger trains must all be considered. The strengths and weakness of current methods for measuring the fire performance of rail transportation systems are evaluated. A systems approach to fire safety which address typical passenger train fire scenatios is analyzed. A rationale is presented for the direction in which most fire science-oriented organizations in the world are clearly headed – the use of fire hazard and fire risk assessment methods supported by measurement methods based on heat release rate.     

Post-flashover compartment fires—application of a theoretical model

Numerical solutions of the post-flashover fire are considered and a computer program is presented. The solutions are compared with experiment and the sensitivity of the solutions to a number of variables is discussed. It is shown that increasing the ventilation may either increase or decrease fire intensity, and the importasnce of the ventilation controlled phase of the fire is discussed. Application of the model to calculate the expected time-temperature history is illustrated and its significance is discussed. The deterministic approach is compared with a new method for calculating the most severe fire by letting one variable take any value between certain limits. The latter method is called pessimization. The significance for designers is noted.