Views:3 Author:Site Editor Publish Time: 2019-10-29 Origin:Site
Determination of combustion properties in cone calorimeter
A plurality of performance parameters of the combustion debris can be obtained using a cone calorimeter, such as heat release rate, mass loss rate, smoke generation rate, effective heat of combustion, ignition time, and toxicity and corrosivity concerning combustion gases. These performance parameters are determined under stable, real, and controllable conditions, and can be repeated at different times and locations. Therefore, it can be used as a reference for literature reference data to provide literature data for more research materials.
1. Heat release rate (HRR.)
HRR is the rate of heat release per unit area after the material is ignited at a preset incident heat flux intensity.
HRR is a more important performance parameter for characterizing fire intensity, the unit is kW/m2. The larger value of HRR is peak of HRR (pkHRR), and the size of pkHRR characterizes the degree of heat release during burning of materials. If the larger the HRR and the pkHRR, the greater the heat release form the combustion of the material,the greater the risk of fire.
2. Total Heat Release (THR)
THR is the sum of the heat released by the material from ignition to flame extinction at a preset incident heat flux intensity. The unit is MJ/m2.
Combining HRR with THR can better evaluate the flammability and flame retardancy of materials, and has a more objective and comprehensive guidance for fire research.
3. Mass Loss Rate (MLR)
MLR refers to the rate of change of mass of a combustion sample over time during combustion. It reflects the degree of thermal cracking, volatilization and combustion of the material at a certain fire intensity.
The MLR value is calculated from a 5-point numerical differential equation. The unit of MLR is g/s.
In addition to the mass loss rate, the COONE can also obtain a mass loss curve to obtain the residue quality at different times, which is convenient for visual analysis of the cracking behavior of the combustion sample.
4. Smoke Produce Rate (SPR)
SPR is defined as the ratio of the extinction area to the mass loss rate in m2/s, ie, SEA is the specific extinction area, and SEA is the smoke produced by the material of the volatilization unit mass. It is not directly It indicates the amount of smoke, which is only a conversion factor for calculating the amount of smoke, in m2/kg.
Similarly, the Total Smoke Rate can be obtained by integration, TSR = ∫SPR, and TSR is the total amount of accumulated smoke when the unit sample area is burned, and the unit is m2/m2.
5. Effective Heat Combustion (EHC)
EHC indicates the ratio of the measured heat release rate to the mass loss rate at a certain time t. It reflects the degree of combustion of volatile gases in the gas phase flame and is useful for analyzing the flame retardant mechanism. The unit of EHC is MJkg-1.
6. Time to Ignition (TTI)
TTI is an important parameter (unit: s) for evaluating the fire resistance of a material. It refers to the time it takes for the surface to heat up from the surface of the material to the surface under the preset incident heat flow intensity. TTI can be used to evaluate and compare the fire resistance of materials.
7. Toxicity determination
When the material burns, it emits a variety of gases, including toxic gases such as CO, HCN, SO2, HCl, H2S, etc. The toxic gas has great harm to the human body, and its composition and percentage can be added by the cone calorimeter. Equipment collection analysis.