The Development of High Expansion Foam Systems for the Suppression of Respirable Coal Dust

摘要

The current practice of mining coal underground with continuous mining machines provides levels of coal dust in the immediate area beyond the limits deemed safe for continuing exposure of the operating personnel. Effective control of the respirable portion of the dust has not been possible with the current methods of allaying the dust. The present practice depends on water sprays to minimize the amount of dust generated and face ventilation to remove that which does become airborne. Solutions, therefore, are required which can be applied to the current operations. A number of solutions have been proposed to accomplish this result on existing machinery. Among these, and one with considerable merit, is the use of high expansion foam to blanket the cutting operation, preventing the release of dust into the air. This is not a new system. In almost every instance where foam application was such that the dust was not allowed to become airborne, significant reductions in dust concentrations were noted. In each case, however, there were drawbacks to prevent the use of foam for dust suppression, not the least of which were the economics involved. The failure of detergent foams to achieve practical results in these tests should in no way reflect on its ultimate ability as a method of dust control.