Abstract: This disclosure relates to fabrication of quartz hollow cylinder with reduced bubbles using atmospheric control. An example horizontal rotating arc furnace includes a housing, supports, and a rotary union. The housing defines an interior configured to receive silica particles and electrodes that generate a plasma arc and includes a plurality of first ports on an exterior of the housing fluidly connected to the interior and supply pipes fluidly coupled to the first ports. The supports mechanically couple the housing to a drive system to provide rotational motion to the housing. The rotary union is coupled to the housing includes second ports to fluidly connect to a vacuum supply. The second ports are fluidly connected to the first ports via the supply pipes. The horizontal rotating arc furnace is configured to apply a vacuum to the interior of the housing via the first ports when the housing is spinning.

Abstract: Methods for improving the efficiency of infrared (IR) halogen lamps and IR halogen lamps having improved efficiency are disclosed. In a method of aligning a filament in a lamp body, the lamp body having the filament therein is rotated, and tubular end portions are heated and necked down which may assist in positioning the filament within the lamp and reduce end losses. IR halogen lamps formed from glass tubes having an OD less than 5 mm are also disclosed. The reduced diameter of the glass tubing increases the surface area for IR energy reflection and reduces end losses. Spuds or beads may be used to position the filament within the lamp.

Abstract: Methods for improving the efficiency of infrared (IR) halogen lamps and IR halogen lamps having improved efficiency are disclosed. In a method of aligning a filament in a lamp body, the lamp body having the filament therein is rotated, and tubular end portions are heated and necked down which may assist in positioning the filament within the lamp and reduce end losses. IR halogen lamps formed from glass tubes having an OD less than 5 mm are also disclosed. The reduced diameter of the glass tubing increases the surface area for IR energy reflection and reduces end losses. Spuds or beads may be used to position the filament within the lamp.

Abstract: A method for monitoring and/or controlling performance of a selective catalytic reduction (SCR) emission control system includes injecting a quantity of a pollution neutralizing gas into a combustion gas stream containing a pollutant gas. The method also includes passing the stream over a catalyst bed to facilitate a reaction of the pollution neutralizing gas with the pollutant gas to produce an effluent and measuring a ratio of the pollution neutralizing gas to the pollutant gas in the effluent.

Abstract: A crucible for melting a silica for fusion of said silica into a desired shape. The crucible having a main body with inner and outer surfaces comprised of a refractory material. In addition, at least a portion of the inner surface includes a barrier layer comprised of a material selected from rhenium, osmium, iridium, and mixtures thereof. An inlet tube to the crucible being provided to supply an oxidizing gas to a melt zone.

Abstract: A fused quartz article, such as a muffle tube or crucible, with enhanced creep resistance. The enhanced creep resistance is the result of controlled devitrification of the fused quartz article. Controlled devitrification is achieved by coating the article with a colloidal silica slurry doped with metal cations, such as barium, strontium, and calcium. The metal cations in the slurry promote nucleation and growth of cristobalite crystals into the fused quartz at temperatures in the range from about 1000° C. to about 1600° C. The cristobalite has significantly. higher viscosity, and therefore greater creep resistance at elevated temperatures, than fused quartz. Methods for applying a doped coating to a fused quartz article and improving the creep resistance of a fused quartz article are also disclosed.

Abstract: A crucible for melting a silica for fusion of said silica into a desired shape. The crucible having a main body with inner and outer surfaces comprised of a refractory material. In addition, at least a portion of the inner surface includes a barrier layer comprised of a material selected from rhenium, osmium, iridium, and mixtures thereof. An inlet tube to the crucible being provided to supply an oxidizing gas to a melt zone.

Abstract: A silica deposition tube is fused in a deuterium (D2) gas atmosphere and optionally baked in a deuterium (D2) gas atmosphere to substantially reduce the hydrogen content in the tube for decreased fiber attenuation. Alternatively, raw silica material is pre-treated in D2 gas followed by fusing of the raw silica tube in a D2 gas environment.