Provided are an apparatus for producing inorganic powder, and a method of producing inorganic powder by using such. The apparatus includes a vaporization part where a condensed-phase precursor is vaporized to obtain a gas-phase precursor, a partial precipitation part where the gas-phase precursor obtained in the vaporization part is partially precipitated to a condensed phase, and a reaction part where the gas-phase precursor remaining after being partially precipitated to a condensed phase in the partial precipitation part reacts with a reaction gas to obtain inorganic powder. An equilibrium vapor pressure of the gas-phase precursor in the partial precipitation part is lower than a vapor pressure of the gas-phase precursor obtained in the vaporization part, and an equilibrium vapor pressure of the precursor in the reaction part is equal to or higher than a vapor pressure of the gas-phase precursor partially precipitated to a condensed phase in the partial precipitation part.

Provided are an apparatus for producing inorganic powder, and a method of producing inorganic powder by using such. The apparatus includes a vaporization part where a condensed-phase precursor is vaporized to obtain a gas-phase precursor, a partial precipitation part where the gas-phase precursor obtained in the vaporization part is partially precipitated to a condensed phase, and a reaction part where the gas-phase precursor remaining after being partially precipitated to a condensed phase in the partial precipitation part reacts with a reaction gas to obtain inorganic powder. An equilibrium vapor pressure of the gas-phase precursor in the partial precipitation part is lower than a vapor pressure of the gas-phase precursor obtained in the vaporization part, and an equilibrium vapor pressure of the precursor in the reaction part is equal to or higher than a vapor pressure of the gas-phase precursor partially precipitated to a condensed phase in the partial precipitation part.

Deposition on a sightglass in a reactor for CVD deposition of silicon is reduced by conducting a first purge gas stream substantially parallel to the reactor end surface of the sightglass, and conducting a second purge gas stream within the sightglass tube at an angle from the sightglass surface toward the interior of the reactor.

An apparatus and method for manufacturing solid particles based on inert gas evaporation. The method includes forming a continuous gaseous feed flow, and injecting the continuous gaseous feed flow through an inlet into a free-space region of a reactor chamber in the form of a feed jet flow, and forming at least one continuous jet flow of a cooling fluid and injecting the at least one jet flow of cooling fluid into the reaction chamber. The feed jet flow is made by passing the feed flow at a pressure above the reactor chamber pressure in the range from 0.01.Math.10.sup.5 to 20.Math.10.sup.5 Pa through an injection nozzle. The jet flow of cooling fluid is made by passing the cooling fluid through an injection nozzle which directs the jet flow of cooling fluid such that it intersects the feed jet flow with an intersection angle between 30 and 150°.

An apparatus and method for manufacturing solid particles based on inert gas evaporation. The method includes forming a continuous gaseous feed flow, and injecting the continuous gaseous feed flow through an inlet into a free-space region of a reactor chamber in the form of a feed jet flow, and forming at least one continuous jet flow of a cooling fluid and injecting the at least one jet flow of cooling fluid into the reaction chamber. The feed jet flow is made by passing the feed flow at a pressure above the reactor chamber pressure in the range from 0.01.Math.10.sup.5 to 20.Math.10.sup.5 Pa through an injection nozzle. The jet flow of cooling fluid is made by passing the cooling fluid through an injection nozzle which directs the jet flow of cooling fluid such that it intersects the feed jet flow with an intersection angle between 30 and 150°.

According to the present invention, there is provided a polysilicon production apparatus including: a horizontal reaction tube having an inlet port through which gaseous raw materials including reactant gases and a reducing gas are supplied, an outlet port through which residual gases exit, a reaction surface with which the gaseous raw materials come into contact, and bottom openings through which molten polysilicon produced by the reactions of the gaseous raw materials is discharged; and first heating means adapted to heat the reaction surface of the horizontal reaction tube. The horizontal reaction tube includes reaction regions consisting of first reaction regions where polysilicon is deposited and second reaction regions where reaction by-products are converted to the reactant gases. The first reaction regions are connected in series with the second reaction regions. Also provided is a polysilicon production method using the polysilicon production apparatus.

A method for converting uranium hexafluoride to uranium dioxide includes steps of hydrolysis of UF.sub.6 to uranium oxyfluoride (UO.sub.2F.sub.2) in a hydrolysis reactor (4) by reaction between gaseous UF.sub.6 and dry water vapour injected into the reactor (4), and pyrohydrolysis of UO.sub.2F.sub.2 to UO.sub.2 in a pyrohydrolysis furnace (6) by reaction of UO.sub.2F.sub.2 with dry water vapour and hydrogen gas (H.sub.2) injected into the furnace (6). The hourly mass flowrate of gaseous UF.sub.6 supplied to the reactor (4) is between 75 and 130 kg/h, the hourly mass flowrate of dry water vapour supplied to the reactor (4) for hydrolysis is between 15 and 30 kg/h, and the temperature inside the reactor (4) is between 150 and 250° C.

A method for converting uranium hexafluoride to uranium dioxide includes steps of hydrolysis of UF.sub.6 to uranium oxyfluoride (UO.sub.2F.sub.2) in a hydrolysis reactor (4) by reaction between gaseous UF.sub.6 and dry water vapour injected into the reactor (4), and pyrohydrolysis of UO.sub.2F.sub.2 to UO.sub.2 in a pyrohydrolysis furnace (6) by reaction of UO.sub.2F.sub.2 with dry water vapour and hydrogen gas (H.sub.2) injected into the furnace (6). The hourly mass flowrate of gaseous UF.sub.6 supplied to the reactor (4) is between 75 and 130 kg/h, the hourly mass flowrate of dry water vapour supplied to the reactor (4) for hydrolysis is between 15 and 30 kg/h, and the temperature inside the reactor (4) is between 150 and 250° C.

A nuclear fuel powder production plant comprises a conversion installation (2) for the conversion of uranium hexafluoride (UF.sub.6) into uranium dioxide (UO.sub.2) having a hydrolysis reactor (4) for the conversion of UF.sub.6 into uranium oxyfluoride powder (UO.sub.2F.sub.2) and a pyrohydrolysis furnace (6) for converting the UO.sub.2F.sub.2 powder into UO.sub.2 powder. The nuclear fuel powder production plant also includes a packaging unit (20) for the UO.sub.2 powder comprising a filling station (22) having a chamber (26) for receiving a container (24) to be filled, a filling duct (28) supplied from the furnace (6) and a suction system (32) comprising a suction ring (34) disposed at the outlet (30) of the filling duct (28) for sucking an annular air flow (A) around a stream (P) of UO.sub.2 powder falling from the outlet (30) from the filling duct (28) into the container (24).

A pressure-control temperature-control hypergravity experimental device includes a high pressure reactor, a hydraulic oil station, a manifold board, a hypergravity water pressure control module, a hypergravity mining control module, a kettle body temperature control module, and a data collection box. The hydraulic oil station is connected to the manifold board and then two paths are formed. The two paths are respectively connected to the high pressure reactor via the hypergravity water pressure control module and the hypergravity mining control module. The kettle body temperature control module is connected to the high pressure reactor. The high pressure reactor, the manifold board, the data collection box, the hypergravity water pressure control module and the hypergravity mining control module are disposed on a hypergravity centrifuge air-conditioning chamber. The hydraulic oil station, a computer and the kettle body temperature control module are disposed outside the hypergravity centrifuge air-conditioning chamber.