Abstract: A method of operating a fluidized bed deposition reactor to provide top removal of granular material, including production product is set forth. The vertical generally cylindrical reactor has at least one gas inlet at the lower end, at least one gas and solids outlet at the upper end and a gas/granular product separator connected to the gas and solids outlet. A heated reaction zone located in the lower portion of the reactor includes a fluidized bed; the bed being fluidized to establish a bubbling fluidized bed with a defined stable height. A disengaging space is provided above the stable bed height. A reaction gas is added to the bottom of the reactor, the reaction gas depositing a reaction product coating on the granular particles, the coating being abraded off the granules. The combined flow rate of the fluidizing gas and the reaction gas is adjusted so that a majority of the granular particles are retained in the reactor while maintaining bubbling.

Abstract: A gas-solids contactor modification is described which provides for starting or restarting the gas flow to the gas-solids contactor when it is filled with solid particles while preventing the solids from entering and blocking one or more gas inlets which have diameters greater than the solid particle diameters. The apparatus modification comprises a gas plenum and one or more chambers within the gas plenum located between the contactor inlet and the gas inlet. The wall of the chamber has multiple passageways therethrough that are smaller in diameter than the majority of the bed particles. Gas feed to the plenum must pass through the passageways in the chamber walls before entering the contactor. In one embodiment the total open area of the passageways is at least as large as the cross-sectional area of the gas inlet and the inlet to the contactor.

Abstract: A dual wall axial flow electric heater for leak sensitive applications provides an improved corrosion and leak resistant assembly and includes protective tubes over electrical heater rods, double tubesheets spaced apart by a plenum and leak detectors positioned to sensor leaks through the walls of the protective tubes. The design includes the option of two or more tube bundles with each inserted into opposite ends of a shell surrounding the tube sheets and heaters. The design provides ease of maintenance since each heater rod can be replaced independently while the unit is in service. Variable heat flux is provided from standard single flux heater rods by providing protective tubes of varying diameters. A built-in thermowell is provided to allow the rod temperatures to be monitored directly. Hot spots are avoided by the use of turning baffles and vibration is avoided by use of spider baffles to support the tubes.

Abstract: A process of hydrogenation of a silicon tetrahalide and silicon to a trihalosilane comprising: providing a vessel with at least one inlet and one outlet with a plurality of silicon particles located in a bed inside the vessel and feeding a mixture of gases consisting primarily of a silicon tetrahalide and hydrogen. A calculational procedure is provided where the flow rate of the gases and the incoming size of the silicon particulates are chosen so that at least 90% of the volume of the bed is free of bubbles after allowance for decrease in particle size due to the reaction and attrition resulting in a higher yield of the trihalosilane.

Abstract: A reactor for hydrogenation of a silicon tetrahalide and metallurgical grade silicon to trihalosilane includes a bed of metallurgical silicon particles, one or more gas entry ports, one or more solids entry ports, one or more solids drains and one or more ports for removing the trihalosilane from the reactor. Fresh surfaces are generated on the bed particles by internal grinding and abrasion as a result of entraining feed silicon particles in a silicon tetrahalide/hydrogen feed stream entering the reactor and impinging that stream on the bed of silicon particles. This has the advantages of higher yield of the trihalosilane, higher burnup rate of the MGS, removal of spent MGS as a fine dust carryover in the trihalosilane effluent leaving the reactor and longer times between shutdowns for bed removal.

Abstract: A gas-solids contactor modification is described which provides for starting or restarting the gas flow to the gas-solids contactor when it is filled with solid particles while preventing the solids from entering and blocking one or more gas inlets which have diameters greater than the solid particle diameters. The apparatus modification comprises a gas plenum and one or more chambers within the gas plenum located between the contactor inlet and the gas inlet. The wall of the chamber has multiple passageways therethrough that are smaller in diameter than the majority of the bed particles. Gas feed to the plenum must pass through the passageways in the chamber walls before entering the contactor. In one embodiment the total open area of the passageways is at least as large as the cross-sectional area of the gas inlet and the inlet to the contactor.

Abstract: A dual wall axial flow electric heater for leak sensitive applications provides an improved corrosion and leak resistant assembly and includes protective tubes over electrical heater rods, double tubesheets spaced apart by a plenum and leak detectors positioned to sensor leaks through the walls of the protective tubes. The design includes the option of two or more tube bundles with each inserted into opposite ends of a shell surrounding the tube sheets and heaters. The design provides ease of maintenance since each heater rod can be replaced independently while the unit is in service. Variable heat flux is provided from standard single flux heater rods by providing protective tubes of varying diameters. A built-in thermowell is provided to allow the rod temperatures to be monitored directly. Hot spots are avoided by the use of turning baffles and vibration is avoided by use of spider baffles to support the tubes.

Abstract: Two low cost processes for removing boron, phosphorus, carbon and titanium during the process of converting metallurgical grade silicon to electronic grade silicon are described. A first process removes boron and titanium by using one or more high temperature solids removal devices for the removal of solid titanium diboride from a halosilane reactor effluent stream where the high temperature is greater than about 200° C. A second process removes carbon as methane and phosphorus as phosphine by means of a membrane separator which processes all or part of a hydrogen recycle stream to recover hydrogen while rejecting methane and phosphine.

Abstract: A process for removing aluminum and other metal chlorides from liquid chlorosilanes with the steps of: introducing a source of seed into a source of impure liquid chlorosilanes, initiating the crystallization of aluminum and other metal chlorides on the seed from the liquid chlorosilanes in a first agitated vessel, passing the resulting mixture of liquid and solids through a cooler into a second agitated vessel for additional crystallization, transferring the resulting mixture of liquid and solids into a solids removal device, transferring the liquid with reduced solids content to a further process or vessel and transferring the liquid with high solids content into a waste concentration device, passing the resulting liquid with reduced solids content to a further process or vessel and passing the resultant liquid with very high solids content to a waste storage vessel with agitation.

Abstract: A reactor for hydrogenation of a silicon tetrahalide and metallurgical grade silicon to trihalosilane includes a bed of metallurgical silicon particles, one or more gas entry ports, one or more solids entry ports, one or more solids drains and one or more ports for removing the trihalosilane from the reactor. Fresh surfaces are generated on the bed particles by internal grinding and abrasion as a result of entraining feed silicon particles in a silicon tetrahalide/hydrogen feed stream entering the reactor and impinging that stream on the bed of silicon particles. This has the advantages of higher yield of the trihalosilane, higher burnup rate of the MGS, removal of spent MGS as a fine dust carryover in the trihalosilane effluent leaving the reactor and longer times between shutdowns for bed removal.

Abstract: A method of operating a fluidized bed deposition reactor to provide top removal of granular material, including production product is set forth. The vertical generally cylindrical reactor has at least one gas inlet at the lower end, at least one gas and solids outlet at the upper end and a gas/granular product separator connected to the gas and solids outlet. A heated reaction zone located in the lower portion of the reactor includes a fluidized bed; the bed being fluidized to establish a bubbling fluidized bed with a defined stable height. A disengaging space is provided above the stable bed height. A reaction gas is added to the bottom of the reactor, the reaction gas depositing a reaction product coating on the granular particles, the coating being abraded off the granules. The combined flow rate of the fluidizing gas and the reaction gas is adjusted so that a majority of the granular particles are retained in the reactor while maintaining bubbling.

Abstract: A process for high temperature hydrolysis of halosilanes and halides with the steps of: providing a bed of fluidized particulate material heated to at least 300° C., injecting steam and an excess of reactants into the reactor, removing solid waste from a bottom outlet, removing the effluent gases through a solids removal device such as a cyclone, condensing and separating some of the unreacted waste from the effluent gas in a distillation column and sending the effluent gases containing hydrogen and hydrogen chloride to a compressor. In a preferred embodiment the reactants contain at least one water reactive halide, selected from the group halosilane, organohalosilane, aluminum halide, titanium halide, boron halide, manganese halide, copper halide, iron halide, chromium halide, nickel halide, indium halide, gallium halide and phosphorus halide and where the halide content is selected from chlorine, bromine and iodine.

Abstract: A process for removing aluminum and other metal chlorides from liquid chlorosilanes with the steps of: introducing a source of seed into a source of impure liquid chlorosilanes, initiating the crystallization of aluminum and other metal chlorides on the seed from the liquid chlorosilanes in a first agitated vessel, passing the resulting mixture of liquid and solids through a cooler into a second agitated vessel for additional crystallization, transferring the resulting mixture of liquid and solids into a solids removal device, transferring the liquid with reduced solids content to a further process or vessel and transferring the liquid with high solids content into a waste concentration device, passing the resulting liquid with reduced solids content to a further process or vessel and passing the resultant liquid with very high solids content to a waste storage vessel with agitation.

Abstract: Removal of the product from the top of the reactor enables a decreased disengaging height and provides a passive means of controlling the bed level despite deposition increasing the weight and height of the bed. The savings from reducing the disengaging height allow use of a taller fluidized bed in a shorter overall reactor length and thus provides increased production with reduced reactor cost. The separation of the gas inlet from the product outlet allows the gas inlet area to be cooler than the product outlet. The separation of the product grinding, caused by the inlet gas, from the product outlet reduces the loss of seed in the product and produces a more uniform product. Removing the hot product and the hot gas at the same place allows energy recovery from both in a single step.

Abstract: A method for safely handling unstable hydrides, such as germane, in an enclosure which has one or more openings, by partitioning the enclosure into smaller but interconnected volumes and providing heat storage and transfer within the enclosure to rapidly remove heat from any incipient hot spot before it can reach a temperature where it could rapidly propagate to the rest of the enclosure. A preferred embodiment includes where the partitioning material comprises part or all of the means to store the heat and has a large surface area to rapidly adsorb heat from the gases in the smaller volume. An even more preferred embodiment is where the partitioning material comprises materials that can be poured into the enclosure. The use of sensible heat, phase change or chemical reactions are feasible ways to store the heat.