Method of applying a free flowing insulating fill material

Claim 1

AN IMPROVED METHOD OF APPLYING PARTICULATE INSULATING FILL MATERIALS HAVING LOW BULK DENSITITES AND FLUIDLIKE FLOW CHARACTERISTICS TO THE INTEIOR CAVITY OF AN IMPERVIOUS RETAINING CASING AND CONTROLLING THE APPLIED DENSITY OF THE PARTICULATE INSULATING FILL MATERIAL; THE IMPROVED METHOD COMPRISING THE STEPS OF: (A) COMBINING PARTICULATE SOLID INSULATING FILL MATERIALS OF AT LEAST ONE MEMBER SELECTED FROM THE GROUP CONSISTING OF SILICA AEROGEL AND PYROGENIC COLLOIDAL SILICA HAVING INITIAL DRY BULK DENSITIES LESS THAN ABOUT 10 LBS./CU. FT., FLUID-LIKE FLOW CHARACTERISTICS AND AN ULTIMATE STRUCTURAL UNIT HAVING AN AVERAGE EFFECTIVE PORE SPACE BETWEEN THE SMALLEST OF SAID STRUCTURAL UNITS OF THE SAME ORDER OF MAGNITUDE AS THE MEAN FREE PATH OF THE MOLECULES COMPRISING AIR AT 150*F. AND ATMOSPHERIC PRESSURE, WITH NON-POLAR LIQUID HYDROCARBON HAVING A BOILING POINT OF AT LEAST APPROXIMATELY 75*F. AND THEREBY PROVIDING COHESIVE PARTICULATE SOLIDS, SAID PARTICULATE SOLID INSULATING FILL BEING COMBINED IN AMOUNT APPROXIMATELY SUFFICIENT TO PROVIDE THE SOLIDS DENSITY DESIRED IN THE DRY INSULATING FILL AND SAID NON-POLAR LIQUID HYDROCARBON BEING COMBINED IN AMOUNT OF AN APPROXIMATELY EQUIVALENT VOLUME OF THE CAVITY OF THE RETAINING CASING LESS THE APPROXIMATE ACTUAL SOLIDS VOLUME OF THE INSULATING FILL MATERIALS; (B) THEN INTRODUCING THE COHESIVE PARTICULATE SOLIDS COMPRISING THE COMBINED LOW DENSITY PARTICULATE SOLID INSULATING FILL MATERIALS AND NON-POLAR LIQUID HYDROCARBON INTO THE CAVITY FORMED BY THE CASING; AND, (C) REMOVING THE NON-POLAR LIQUID HYDROCARBON BY EVAPORATION.