Showing papers on "Charring published in 1974"
Patent•
15 May 1974
TL;DR: In this article, a method for converting organic waste materials into inert humus-like materials by charring the organic waste material by heating and drying same in the presence of certain water-soluble inorganic acids, removing residual acid and other watersoluble contaminants by washing the crude char product with water, and utilizing the resulting inert material as a landfill.
Abstract: A method for converting organic waste materials into inert humus-like materials by charring the organic waste materials by heating and drying same in the presence of certain water-soluble inorganic acids, removing residual acid and other water-soluble contaminants by washing the crude char product with water, and utilizing the resulting inert material as a landfill. If desired, the humus-like char products can be reacted with an alkali at elevated temperatures, and the resulting alkali salts of humic-acid-like materials can be mixed with the soil to provide an improved and/or fertilized topsoil.
30 citations
TL;DR: In this paper, two contrasted approaches to ablative thermal protection of Venus entry probes are presented -a typical carbonaceous charring ablator and a dielectric reflective ablator.
Abstract: Two contrasted approaches to ablative thermal protection of Venus entry probes are presented - a typical carbonaceous charring ablator and a dielectric reflective ablator. The interesting observation in this study is that mass loss is not the controlling variable in heat-shield sizing. A heat-soak problem determines the carbon phenolic sizing. For Teflon, the material thickness required to accomplish reflection is the sizing factor. The total heat-shield weight required to handle either steep or shallow entry is computed to be 13% less for a Teflon shield (if at least 3.2 mm are required for reflection) than for a charring ablator shield. If an efficient reflective backing is used with Teflon, the thickness can be reduced 1.0 mm and the computed weight is 31% less for Teflon than for the charring ablator. Such weight reductions may significantly increase the science payload weight of the miniprobes.
25 citations
TL;DR: In this article, the effect of the charring temperature on the final response and to determine at what temperature significant losses were occurring were investigated in three matrices obtained from air pollution studies, and it was found that Pb and Cd were lost in charring above 500°C and 330°C, respectively, and the loss rate differed for the different matrices.
Abstract: A preatomizing (charring) step is customarily used in flameless atomic absorption spectroscopy. Experiments were carried out to investigate the effect of the charring temperature on the final response and to determine at what temperature significant losses were occurring. Four elements of environmental significance (Pb, Cd, Be, V) were investigated in three matrices obtained from air pollution studies. It was found that Pb and Cd were lost in charring above 500°C and 330°C, respectively, and that the loss rate differed for the different matrices. The maximum charring temperatures for Be and V were 900°C and 1280°C, respectively. Preatomization losses were also examined for Co, Ni, Fe and Cu in aqueous solution. Several effects which could be explained by a change in atomization rate were noted at low charring temperatures.
11 citations
01 Jul 1974
TL;DR: In this article, the material thermal response for heat shields of blunt probes entering Saturn and Uranus was investigated and the solutions show that Teflon heat shields are sized by mass loss considerations, other materials (unless entering the Uranus cold-dense atmosphere) by heat soak considerations, steeper entries require less heat shield mass, and sizing requirements vary little about the bodies for heat soak dominated materials, and carbon-phenolic appears superior overall.
Abstract: Solutions are presented for the material thermal response for heat shields of blunt probes entering Saturn and Uranus. Both monolithic and sandwich concepts were considered having exposed charring ablative or reflective materials. The solutions show that (1) Teflon heat shields are sized by mass loss considerations, other materials (unless entering the Uranus cold-dense atmosphere) by heat soak considerations, (2) steeper entries require less heat shield mass, (3) sizing requirements vary little about the bodies for heat soak dominated materials, and (4) carbon-phenolic appears superior overall, but silica is superior for the steeper entries and the high helium content atmospheres.
8 citations
7 citations
15 Jul 1974
6 citations
01 Jun 1974
TL;DR: In this paper, the thermochemical response of Coating 313 when exposed to a fuel fire environment was studied to provide a tool for predicting the reaction time, and the existing Aerotherm Charring Material Thermal Response and Ablation (CMA) computer program was modified to treat swelling materials.
Abstract: The thermochemical response of Coating 313 when exposed to a fuel fire environment was studied to provide a tool for predicting the reaction time. The existing Aerotherm Charring Material Thermal Response and Ablation (CMA) computer program was modified to treat swelling materials. The modified code is now designated Aerotherm Transient Response of Intumescing Materials (TRIM) code. In addition, thermophysical property data for Coating 313 were analyzed and reduced for use in the TRIM code. An input data sensitivity study was performed, and performance tests of Coating 313/steel substrate models were carried out. The end product is a reliable computational model, the TRIM code, which was thoroughly validated for Coating 313. The tasks reported include: generation of input data, development of swell model and implementation in TRIM code, sensitivity study, acquisition of experimental data, comparisons of predictions with data, and predictions with intermediate insulation.
4 citations