| OCR Text |
Show »=1 where L m is the limit of the fuel mixture (% by volume), L, is the corresponding limit of any fuel component T, and 'yi' is the molar (volumetric) fraction of the fuel component T in the fuel mixture. ii. Flammability limit data for the individual components of any fuel mixture need to be obtained for the same conditions and mode of flame propagation. W h e n no such data are available, then any needed limit values can be estimated, using procedures such those outlined previously, from whatever data that may be available for the particular fuel component in question, (such as the limit of a fuel component may be known only for a certain temperature while the corresponding data for the remaining components are known at other temperatures). iii. Generally, the Rule applies well to the determination of the lean limit but less reliably for the rich limit. There are notable exceptions in relation to some of the fuel combinations where it does not apply either because some chemical interaction may take place between the fuel components themselves or the presence of the component no longer permits another component to behave obliviously of the presence of others. This is especially the case for the rich limit when hydrogen or saturated hydrocarbon fuels are mixed with unsaturated or oxygenated fuels, such as H 2 + C 2H4 or C H 4 + C H 2 0 mixtures. iv. If a fuel mixture that follows the Rule well is mixed with another also obeying the Rule then its application leads to a good estimation of the limit of the resulting mixture. But the mixing of a fuel mixture that does not obey the Rule with another fuel, then the Rule can yield useful approximate results when the measured value of the limit of the non-complying "fuel mixture" is used. v. For a fuel mixture that contains in addition to the fuel components some diluents, the Rule can be used while assuming the diluent to be associated with one of the fuel components or distributed among more than one component. These resulting assumed diluted fuels can be treated as individual fuels, having their measured or calculated limits in association with the diluents. Acknowledgements The financial assistance of the Canadian Natural Sciences and Engineering Council (N. S. E. R. C.) is acknowledged. The contributions to this paper of former associates and students of the authors Messers Bade Shrestha, K. Harris, H. Cheng and S. B o o n are appreciated. |
