Literature Survey on Materials to Improve Low Temperature Fluidity of Fog Oil

摘要

The liquid mineral oil used as fog oil in smoke generation becomes too viscous tomeet the flow requirements of the M157, M1059, M56, and M58 smoke generator systems at low temperatures. Historically, diesel fuel has been added to the cold mineral oil as a flow enhancer, but this practice introduces an obscurant whose procurement specification does not contain the same controls as the fog oil specification. This study was conducted to identify commercial products with the potential to replace diesel fuel as a low temperature flow enhancer for mineral oil and to maintain the fog oil standard. Several flow enhancement candidates were identified, including a mineral oil and several synthetic products. The kinematic viscosities of these products remain low even at low temperatures, ranging from 8 to 90 cSt at -25 deg C (-13 deg F), compared to 2851 cSt at -25 deg C for mineral oil alone. The flow enhancers identified in this study could reduce the viscosity of mineral oil so that the blend would be pumpable at the lowest required operating temperature. The cost of each of flow enhancer exceeds that of mineral oil, but cost considerations must take into account the comparatively low usage rate of an extreme cold flow enhancer. Another consideration is the product's human toxicity. Most products identified for this study exhibit a low degree of toxicity as oils, but little is known about their potential toxicity as a fog.