Hypervelocity heat transfer studies in simulated planetary atmospheres final report

Hypervelocity heat transfer studies in simulated planetary atmosphere

A Wear Minimization Design Investigation of Feedline Splitters, Turning Sections, and Feed Nozzles of a Pneumatic Conveyed Solids System

The adverse effects of wear has continually plagued the operation of the TVA 20 MW Atmospheric Fluidized Bed Combustion Pilot Plant. Wear has caused serious problems in all aspects of the pneumatically fed below-bed coal feed system. This has given rise to the development of high wear resistant designs of feedline splitters, turning sections, and feed nozzles. Wear testing of PVC feedline system components was conducted at The University of Tennessee to determine the wear characteristics of different designs. PVC was chosen for the feedline system component material to accelerate the wear testing results. A series of similar tests were conducted to determine the merit of the wear resistant designs. While the testing was limited in scope due to size, material, and operating constraints, the general wear characteristic test results have proven to be valuable in assessing new wear resistant designs. For long radius PVC bend wear testing, the wear rate was found to be proportional to the cube of the transport velocity. A change in solids mass now rate also had a significant effect on the wear rate of the bends, about one half the effect of a change in transport velocity. Wear testing of a standard 45 degree PVC wye showed that a 50 fold increase in the life of the wye compared to a long radius bend can be expected. Two PVC floating valve caps with different recess depths were subjected to similar wear tests. It was found that a recess depth increase from 0.25 to 0.43 inches improved the wear resistance of the valve cap by a factor of six to seven. Testing of a new 1:3 PVC feedline splitter design showed that the new splitter design was very resistant to wear. Testing also showed there was a relationship between the splitter\u27s exit feedline lengths and the split equality. With equal exit feedline lengths, the split equality can be expected to be within ± 5 percent. Two new steel feedline splitters were designed for replacement of the feedline splitters currently used at the TVA Pilot Plant: a 1:3 splitter design for compartments A-D, and a 1:6 splitter design for the modified recycle system. The 1:6 recycle splitter design was installed in the recycle system, and after 486 hours of operation, it has shown great promise. The 1:6 recycle splitter has not plugged, and more significantly, has not shown any observable signs of wear

Mechanical properties of several nickel alloys in hydrogen at elevated temperatures

Tests were performed to determine low cycle fatigue and crack growth rate properties of one iron-base and two forms of one cast nickel-base alloy. The alloys were tested in various forms and/or heat-treat conditions that are proposed for use in a high-pressure hydrogen or a hydrogen-water vapor environment. Some general conclusions can be made comparing the results of tests in a hydrogen environment with those in a hydrogen-water vapor environment. The hydrogen-water vapor environment caused a 50 percent average reduction in fatigue life, indicating extreme degradation when compared with tests conducted in air, for Incoloy 903 at 1033 K (1400 F). Crack growth rates increased significantly for all materials with increasing test temperature. A very significant increase (three orders of magnitude) in crack growth rate occurred for Incoloy 903 tested in the hydrogen-water vapor environment when compared with testing done in hydrogen along at 922 K (1200 F)

Mineral and Fuel Resources Map of Kentucky

The production of minerals and fuels in Kentucky is a multibillion dollar industry. Historically, coal, oil, natural gas, limestone, sand and gravel, clay, fluorite, barite, lead, iron, phosphate, zinc, and brines have been produced in the State. These resources have greatly influenced the development of Kentucky by providing raw materials for the early settlers who settled the State and for current industrial and economic development. Electrical power for homes, businesses, and factories; materials for constructing houses, buildings, automobiles, and roads; and products we consume in everyday life come from the earth\u27s mineral and fuel resources