Laboratory method for investigation of smoke suppressant additives for middle distillate fuels

Many studies have been devoted to the investigation of smoke suppressant additives for diesel fuels. Thus far, however, there is no unified opinion on the mechanism through which these additives are effective. Additives have been tested by the use of many different types of engines, operating conditions, and fuels. The effectiveness of smoke suppressants is usually evaluated in engines by means of the procedures of Hartridge or Bosch. Both methods are quite time-consuming. This paper describes a newly developed laboratory unit and a test determinations. One problem in developing any laboratory method for this purpose is the impossibility of simulating the factors that determine the fuel combustion parameters in an engine cylinder. The authors have predicated their development on the assumption that by the use of a large jet (flame) of hot atomized fuel, it will be possible to rate the effectiveness of additives under laboratory conditions according to the amount of soot formation. Results of the extensive test program, in which various smoke-suppresant additives have been evaluated, are presented and discussed. Synergism of various pairs of additives is demonstrated. 3 refs.