Patents Assigned to Pedro Buarque De Macedo
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Patent number: 5678236Abstract: In this invention radioactive or hazardous containing materials are vitrified in a melter having two or more chambers. Glass feed materials are added to the primary chamber of the melter and they are heated to a molten glass which is then transported to one or more secondary chambers where hazardous and/or radioactive containing materials are added and are encapsulated and/or melted. In addition, the non-plutonium part of a glass feed can be melted in a non-radioactive environment which permits contact operations and maintenance; no radioactive shielding; and a conventional off gas system-similar to commercial vitrification plants. The hot molten "clean" glass is directed into a radioactive containment such as a "glove box"; shielded "glove box"; or hot cell, or a combination of these. By delivering hot "clean" glass from a melter including non-radioactive materials, 90% of the off gases will be non-radioactive.Type: GrantFiled: January 23, 1996Date of Patent: October 14, 1997Assignees: Pedro Buarque De Macedo, Theodore Aaron LitovitzInventors: Pedro B. Macedo, Ian L. Pegg, Hamid Hojaji, Robert K. Mohr, Marek Brandys
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Patent number: 5405590Abstract: An off-gas quencher and solid recovery scrubber unit includes a wet flue gas scrubber which has the dual responsibilities of lowering the temperature of the inlet hot gas entering through the scrubber and trapping contaminants from the gas stream into the liquid stream. The hot exhaust gases are first cooled by evaporating the liquid scrubber solution. The contaminants of the exhaust gas are neutralized by a suitable reagent such as sodium hydroxide and the product is collected in the scrubbing solution. Since the solution is continuously recycled, the concentration of the scrubbing agent will be diminished as the scrubbing proceeds, while the concentration of the scrubbing product in the solution will rise to the solubility limit of the product. The scrubbing products start to precipitate and are collected at the bottom of the scrubber and are withdrawn. The scrubbing reagents are continuously replenished to the scrubber.Type: GrantFiled: February 5, 1993Date of Patent: April 11, 1995Assignees: Pedro Buarque De Macedo, Theodore Aaron LitovitzInventors: Pedro B. D. Macedo, Hamid Hojaji, Marek Brandys, Robert K. Mohr
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Patent number: 5340372Abstract: Material, such as, for example, sealed double bags of asbestos containing waste or ash from infectious waste or toxic material or radioactive waste, is transferred into a glass melt of a furnace. Gas bubbles released into the melt form a gas curtain which causes enhanced mixing of the material to accelerate the dissolution of the components of the added material. The presence of the gas bubbles reduces the cross-section of the molten glass through which current passes, which in turn increases the electrical resistance of the glass melt and therefore increases power generation of the melt or power density at constant current. A highly oxidizing hot region is produced under the location where the material is introduced into the furnace. Drawn off glass is shaped and quenched into at least two sizes of approximate spheres. The spheres are cooled sufficiently fast to be thermally tempered and have a surface compressive strength level above 5000 psi.Type: GrantFiled: June 29, 1992Date of Patent: August 23, 1994Assignees: Pedro Buarque de Macedo, Theodore Aaron LitovitzInventors: Pedro B. Macedo, Robert K. Mohr
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Patent number: 5188649Abstract: Material, such as, for example, sealed double bags of asbestos containing waste or ash from infectious waste or toxic material or radioactive waste, is transferred into a glass melt of a furnace. Gas bubbles released into the melt form a gas curtain which causes enhanced mixing of the material to accelerate the dissolution of the components of the added material. The presence of the gas bubbles reduces the cross-section of the molten glass through which current passes, which in turn increases the electrical resistance of the glass melt and therefore increases power generation of the melt or power density at constant current. A highly oxidizing hot region is produced under the location where the material is introduced into the furnace. Drawn off glass is shaped and quenched into at least two sizes of approximate spheres. The spheres are cooled sufficiently fast to be thermally tempered and have a surface compressive strength level above 5000 psi.Type: GrantFiled: August 7, 1991Date of Patent: February 23, 1993Assignees: Pedro Buarque de Macedo, Theodore Aaron LitovitzInventors: Pedro B. Macedo, Robert K. Mohr
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Patent number: 4430108Abstract: A method of making foam glass by impregnating diatomaceous earth, fly ash or mixtures thereof, and insoluble modifiers, if any, with at least one water soluble glass former in an amount expressed as its oxide of about 2.5 to 20 weight percent of the impregnated diatomaceous earth, fly ash or mixtures thereof; at least one water soluble flux in an amount expressed as its oxide of about 8 to 20 weight percent of the impregnated diatomaceous earth, fly ash or mixtures thereof; and at least one gas generator. The diatomaceous earth, fly ash or mixtures thereof is impregnated by mixing diatomaceous earth, fly ash or mixtures thereof and an impregnating solution comprising at least one water soluble glass former in an amount expressed as its oxide of about 3 to 14 weight percent; at least one water soluble flux in an amount expressed as its oxide of about 10 to 20 weight percent; at least one gas generator, and water in an amount of about 50 to 80 weight percent.Type: GrantFiled: September 14, 1982Date of Patent: February 7, 1984Assignees: Pedro Buarque de Macedo, Theodore Aaron LitovitzInventors: Hamid Hojaji, Pedro B. de Macedo, Theodore A. Litovitz
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Patent number: 4299608Abstract: A glass composition having at least 85 mole percent of SiO.sub.2, where the improvement comprises at least 7 wt percent of at least one member selected from the group consisting of PbO and Bi.sub.2 O.sub.3 and at least 1.5 mole percent of at least one member selected from the group consisting of K.sub.2 O, Rb.sub.2 O and Cs.sub.2 O.Type: GrantFiled: September 14, 1979Date of Patent: November 10, 1981Assignees: Pedro Buarque de Macedo, Theodore Aaron LitovitsInventors: Pedro B. Macedo, Mrinmay Samanta, Joseph H. Simmons
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Patent number: 4244721Abstract: A method for producing a glass article which comprises melting and forming a preshaped glass article having a composition in the phase separable regions of the alkali-boro-silicate or alkali-boro-germania-silicate systems, inducing the article to phase separate, leaching out a silica-poor phase from the surface layers only to form a structure having porous surface layers surrounding a solid region of substantially the original glass composition, washing this structure with an organic media which dissolves oxides of boron and other leaching reaction products, drying and heating to collapse the outer porous structure to form a glass having a silica-rich surface layer surrounding a solid region having substantially the original glass composition.Type: GrantFiled: January 31, 1979Date of Patent: January 13, 1981Assignees: Pedro Buarque de Macedo, Theodore A. LitovitzInventors: Prabhat K. Gupta, Martin G. Drexhage, Pedro B. de Macedo
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Patent number: 4188198Abstract: A glass article is produced by doping a porous glass matrix with at least one member selected from the group consisting of PbO and Bi.sub.2 O.sub.3 and at least one member selected from the group consisting of K.sub.2 O, Rb.sub.2 O and Cs.sub.2 O, and producing a profile in dopant composition by immersion in a multiple-solvent solution.Type: GrantFiled: November 23, 1977Date of Patent: February 12, 1980Assignees: Pedro Buarque de Macedo, Theodore Aaron LitovitsInventors: Pedro B. Macedo, Joseph H. Simmons, Mrinmay Samanta
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Patent number: 4183620Abstract: A glass composition having at least 85 mole percent of SiO.sub.2, where the improvement comprises at least 7 wt percent of at least one member selected from the group consisting of PbO and Bi.sub.2 O.sub.3 and at least 1.5 mole percent of at least one member selected from the group consisting of K.sub.2 O, Rb.sub.2 O and Cs.sub.2 O.Type: GrantFiled: December 30, 1976Date of Patent: January 15, 1980Assignees: Pedro Buarque De Macedo, Theodore Aaron LitovitsInventors: Pedro B. Macedo, Mrinmay Samanta, Joseph H. Simmons
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Patent number: 4181403Abstract: A glass dielectric fiber waveguide with a composition profile varying radially from the center to the surface, the composition profile causing a surface layer which is in compression, said composition profile being caused by (a) at least one dopant used substantially to create a stress profile wherein the surface is in compression, and (b) at least one dopant used substantially for the purpose of creating an index of refraction profile.Type: GrantFiled: December 30, 1976Date of Patent: January 1, 1980Assignees: Pedro Buarque De Macedo, Theodore Aaron LitovitsInventors: Pedro B. Macedo, Robert K. Mohr, Prabhat K. Gupta