VARIABLE TEMPERATURE GRADIENT HEAT PIPE FURNACE ELEMENT

BEGINNING IN THE 1970S NUMEROUS EXPERIMENTAL STUDIES WERE CONDUCTED IN SPACE IN NEAR-ZERO-G ENVIRONMENTS TO STUDY THE EFFECTS OF CRYSTAL GROWTH IN THE ABSENCE OF GRAVITY. THESE TESTS WERE CONDUCTED ABOARD SKYLAB AND DURING THE APOLLO-SOYUZ TEST PROJECT. EVEN THOUGH THE RESULTS PROVED THE ADVANTAGES OF MATERIALS PROCESSING IN SPACE, LIMITATIONSIN THE EQUIPMENT, SUCH AS THE PROCESSING FURNACE, WERE REALIZED. A MORE VERSATILE, HIGHER-TEMPERATURE, VARIABLE-GRADIENT FURNACE IS REQUIRED FOR FUTURE SPACE VENTURES. THE CRYSTAL-GROWING FURNACE MUST HAVE A UNIFORM TEMPERATURE PROFILE WITHIN THE WORK AREA. THE PROFILE MUST BE VARIABLE WITHOUT PHYSICALLY ALTERING THE FURNACE SYSTEM. THE GOAL OF THIS PROJECT IS TO DESIGN AND DEMONSTRATE A VARIABLE-TEMPERATURE-GRADIENT HEAT PIPE TO BE USED IN A MICROGRAVITY ENVIRONMENT. THE VARIABLE-TEMPERATURE PROFILE WILL BE CREATED BY THE DIFFUSION OF THE HEAT-PIPE WORKING FLUID INTO A NON-CONDENSIBLE GAS. THIS CONCEPT WILL PROVIDEA WIDE RANGE OF UNIFORM TEMPERATURE PROFILES AND, AT THE SAME TIME, MINIMIZE MASS AND POWER CONSUMPTION. THE PHASE IWORK EFFORT WILL INCLUDE THE DESIGN, FABRICATION, AND TESTING OF A DEMONSTRATION-MODEL FURNACE ELEMENT TO PROVE FEASIBILITY. PHASE II WOULD INCLUDE THE FABRICATION AND EXTENSIVE TESTING OF A FULL-SCALE MODEL. BEGINNING IN THE 1970S NUMEROUS EXPERIMENTAL STUDIES WERE CONDUCTED IN SPACE IN NEAR-ZERO-G ENVIRONMENTS TO STUDY THE EFFECTS OF CRYSTAL GROWTH IN THE ABSENCE OF GRAVITY. THESE TESTS WERE CONDUCTED ABOARD SKYLAB AND DURING THE APOLLO-SOYUZ TEST PROJECT. EVEN THOUGH THE RESULTS PROVED THE ADVANTAGES OF MATERIALS PROCESSING IN SPACE, LIMITATIONSIN THE EQUIPMENT, SUCH AS THE PROCESSING FURNACE, WERE REALIZED. A MORE VERSATILE, HIGHER-TEMPERATURE, VARIABLE-GRADIENT FURNACE IS REQUIRED FOR FUTURE SPACE VENTURES. THE CRYSTAL-GROWING FURNACE MUST HAVE A UNIFORM TEMPERATURE PROFILE WITHIN THE WORK AREA. THE PROFILE MUST BE VARIABLE WITHOUT PHYSICALLY ALTERING THE FURNACE SYSTEM. THE GOAL OF THIS PROJECT IS TO DESIGN AND DEMONSTRATE A VARIABLE-TEMPERATURE-GRADIENT HEAT PIPE TO BE USED IN A MICROGRAVITY ENVIRONMENT. THE VARIABLE-TEMPERATURE PROFILE WILL BE CREATED BY THE DIFFUSION OF THE HEAT-PIPE WORKING FLUID INTO A NON-CONDENSIBLE GAS. THIS CONCEPT WILL PROVIDEA WIDE RANGE OF UNIFORM TEMPERATURE PROFILES AND, AT THE SAME TIME, MINIMIZE MASS AND POWER CONSUMPTION. THE PHASE IWORK EFFORT WILL INCLUDE THE DESIGN, FABRICATION, AND TESTING OF A DEMONSTRATION-MODEL FURNACE ELEMENT TO PROVE FEASIBILITY. PHASE II WOULD INCLUDE THE FABRICATION AND EXTENSIVE TESTING OF A FULL-SCALE MODEL.