Prototype Salvage Foaming System.

Polyurethane foam is made by mixing MDI Polymeric diphenylmethane diisocyanate and polyol together with a blowing agent such as freon, carbon dioxide, or nitrogen. This mixture expands, then hardens. Battelle investigated developments in polyurethane foam formulations and emplacement equipment, to determine what technology could be adapted for underwater foaming. These studies concluded that the combination of high pressure impingement mixing technology HPIM and a fast reacting foam formulation would produce an improved foam under water. Based on the information and data gathered during the development of the laboratory model and full-scale prototype foaming machines, including the in-house and at-sea tests, the following conclusions are made 1 Making high quality foam underwater is feasible to depths of at least 100 feet. Foam densities of less than 10 poundscubic feet can be obtained. 2 The full-scale prototype foaming machine performs well and provides the high degree of control necessary for good foam making. The machine, with its automatic features, is safer to operate, requires less labor to operate and has less down time than previous models. 3 In order to increase the efficient use of chemicals and prevent nozzle clogging, more development work is warranted in the gun and nozzle design. Future machines should use flow meters that are not affected by changes in chemical viscositytemperature changes. The heater control system will require further investigation and possibly a re-design, to produce a more stable timetemperature profile.