Abstract: Provided is a method for efficiently and continuously producing a cellulose ether containing a reduced amount of indissoluble component. Specifically, the method includes a contact step of bringing pulp into contact with an alkali metal hydroxide solution in the presence of a heat removal solvent to obtain alkali cellulose; a reaction step of subjecting the alkali cellulose to a reaction with an etherifying agent; a partial condensation step, after completion of the reaction, of partially condensing a gas present in a reaction vessel used for the reaction to separate the gas into gas and liquid components for returning some or all of the gas component to the contact step for reuse as some or all of the heat removal solvent; and a step of incinerating the liquid component and, when all of the gas component is not returned to the contact step, the remainder of the gas component.

Abstract: The upper electrode 31 has a hole 35 extending from an upper surface 33 to a lower surface 34, a bolt 36 is inserted from the upper surface 33 of the upper electrode 31 into the hole 35, and secured in a lower electrode 32 by a screw. A gap 51 between an inside of the hole 35 and a straight body portion of the bolt 36 allows the upper electrode 31 to slide in all directions in a placement surface (upper surface of the lower electrode 32 in contact with the lower surface 34 of the upper electrode 31 in FIG. 2) that is a contact surface with an upper surface of the lower electrode 32, thereby providing an effect of preventing occurrence of a crack or a break in a U rod that can be expanded and contracted in all directions during a vapor phase growth process.

Abstract: Provided is a method for efficiently and continuously producing a cellulose ether containing a reduced amount of indissoluble component. Specifically, the method includes a contact step of bringing pulp into contact with an alkali metal hydroxide solution in the presence of a heat removal solvent to obtain alkali cellulose; a reaction step of subjecting the alkali cellulose to a reaction with an etherifying agent; a partial condensation step, after completion of the reaction, of partially condensing a gas present in a reaction vessel used for the reaction to separate the gas into gas and liquid components for returning some or all of the gas component to the contact step for reuse as some or all of the heat removal solvent; and a step of incinerating the liquid component and, when all of the gas component is not returned to the contact step, the remainder of the gas component.

Abstract: A bell jar includes a metallic bell jar (1), and a metallic base plate (2) on which the bell jar (1) is placed, and packing (3) seals an inside of a container. To the base plate (2), a pressure gauge (4), a gas introduction line (5), and a gas discharge line (6) are connected so as to allow monitoring of internal pressure of the bell jar (1) and introduction and discharge of a gas. A vacuum pump (7) is provided in a path of the gas discharge line (6), and the vacuum pump (7) reduces internal pressure of the bell jar so as to be lower than vapor pressure of water. The vacuum pump (7) reduces the internal pressure of the bell jar so as to be lower than vapor pressure of water, thereby efficiently removing moisture, and completing drying of the bell jar in a short time.

Abstract: A bell jar includes a metallic bell jar (1), and a metallic base plate (2) on which the bell jar (1) is placed, and packing (3) seals an inside of a container. To the base plate (2), a pressure gauge (4), a gas introduction line (5), and a gas discharge line (6) are connected so as to allow monitoring of internal pressure of the bell jar (1) and introduction and discharge of a gas. A vacuum pump (7) is provided in a path of the gas discharge line (6), and the vacuum pump (7) reduces internal pressure of the bell jar so as to be lower than vapor pressure of water. The vacuum pump (7) reduces the internal pressure of the bell jar so as to be lower than vapor pressure of water, thereby efficiently removing moisture, and completing drying of the bell jar in a short time.

Abstract: The upper electrode 31 has a hole 35 extending from an upper surface 33 to a lower surface 34, a bolt 36 is inserted from the upper surface 33 of the upper electrode 31 into the hole 35, and secured in a lower electrode 32 by a screw. A gap 51 between an inside of the hole 35 and a straight body portion of the bolt 36 allows the upper electrode 31 to slide in all directions in a placement surface (upper surface of the lower electrode 32 in contact with the lower surface 34 of the upper electrode 31 in FIG. 2) that is a contact surface with an upper surface of the lower electrode 32, thereby providing an effect of preventing occurrence of a crack or a break in a U rod that can be expanded and contracted in all directions during a vapor phase growth process.

Abstract: One end side of a core wire holder 20 is formed into a shape of a truncated cone and has an inclined surface. In the end portion, an opening 22 is provided, and a hollow portion 21 is formed, a silicon core wire 5 being inserted into the hollow portion 21 and held therein. On the surface of the silicon core wire 5, polycrystalline silicon 6 is vapor deposited by the Siemens method to produce a polycrystalline silicon rod. On the inclined surface of the truncated cone portion in the vicinity of the opening 22, as a thermal insulating layer, annular slits 23a to 23c are formed from an outer circumferential surface in the vicinity of the opening toward the hollow portion 21. The annular slit acts as a thermal insulating portion, and suppresses escape of the heat to heat the one end side of the core wire holder 20.

Abstract: A bell jar includes a metallic bell jar (1), and a metallic base plate (2) on which the bell jar (1) is placed, and packing (3) seals an inside of a container. To the base plate (2), a pressure gauge (4), a gas introduction line (5), and a gas discharge line (6) are connected so as to allow monitoring of internal pressure of the bell jar (1) and introduction and discharge of a gas. A vacuum pump (7) is provided in a path of the gas discharge line (6), and the vacuum pump (7) reduces internal pressure of the bell jar so as to be lower than vapor pressure of water. The vacuum pump (7) reduces the internal pressure of the bell jar so as to be lower than vapor pressure of water, thereby efficiently removing moisture, and completing drying of the bell jar in a short time.

Abstract: The present invention is a method of manufacturing polycrystalline silicon rods, wherein silicon is deposited onto a silicon core wire by a chemical vapor deposition (CVD) method such that a silicon member, which is cut out from a single-crystalline silicon ingot at an off-angle range of 5 to 40 degrees relative to a crystal habit line of the ingot, is used as the silicon core wire. The single-crystalline silicon ingot is preferably grown by a Czochralski (CZ) method or floating zone (FZ) method, such that the ingot preferably has an interstitial oxygen concentration of 7 ppma to 20 ppma. Silicon rods produced by this method are less likely to suffer a breakage caused by cleavage during the growth process of polycrystalline silicon during CVD, and exhibit improved FZ method success rates. The polycrystalline silicon rods produced by this method also have low impurity contamination and high single-crystallization efficiency.

Abstract: A water-soluble cellulose ether is separated from its suspension by passing a suspension of water-soluble cellulose ether particles in water through a filter of perforated metallic or ceramic filter medium under pressure, removing the filter cake of water-soluble cellulose ether from the filter medium, and cleaning the filter medium with steam, compressed air or water under pressure. The invention enables to separate a water-soluble cellulose ether, especially having a high dissolution temperature, avoids the filter from being clogged, and extends the operative time of the filter.

Abstract: The upper electrode 31 has a hole 35 extending from an upper surface 33 to a lower surface 34, a bolt 36 is inserted from the upper surface 33 of the upper electrode 31 into the hole 35, and secured in a lower electrode 32 by a screw. A gap 51 between an inside of the hole 35 and a straight body portion of the bolt 36 allows the upper electrode 31 to slide in all directions in a placement surface (upper surface of the lower electrode 32 in contact with the lower surface 34 of the upper electrode 31 in FIG. 2) that is a contact surface with an upper surface of the lower electrode 32, thereby providing an effect of preventing occurrence of a crack or a break in a U rod that can be expanded and contracted in all directions during a vapor phase growth process.

Abstract: One end side of a core wire holder 20 is formed into a shape of a truncated cone and has an inclined surface. In the end portion, an opening 22 is provided, and a hollow portion 21 is formed, a silicon core wire 5 being inserted into the hollow portion 21 and held therein. On the surface of the silicon core wire 5, polycrystalline silicon 6 is vapor deposited by the Siemens method to produce a polycrystalline silicon rod. On the inclined surface of the truncated cone portion in the vicinity of the opening 22, as a thermal insulating layer, annular slits 23a to 23c are formed from an outer circumferential surface in the vicinity of the opening toward the hollow portion 21. The annular slit acts as a thermal insulating portion, and suppresses escape of the heat to heat the one end side of the core wire holder 20.

Abstract: The present invention utilizes a silicon member (single-crystalline silicon rod), which is cut out from a single-crystalline silicon ingot which is grown by a CZ method or FZ method, as the core wire when manufacturing a silicon rod. Specifically, a planar silicon is cut out from a body portion which is obtained by cutting off a shoulder portion and a tail portion from a single-crystalline silicon ingot and is further cut into thin rectangles to obtain a silicon bar. In the case that the crystal growth axis orientation is <100>, there are four crystal habit lines, and the silicon bar is cut out such that the surface forms an off-angle ? in a predetermined range with the crystal habit line. The provided polycrystalline silicon rod has a low impurity contamination and high single-crystallization efficiency.

Abstract: A water-soluble cellulose ether is separated from its suspension by passing a suspension of water-soluble cellulose ether particles in water through a filter of perforated metallic or ceramic filter medium under pressure, removing the filter cake of water-soluble cellulose ether from the filter medium, and cleaning the filter medium with steam, compressed air or water under pressure. The invention enables to separate a water-soluble cellulose ether, especially having a high dissolution temperature, avoids the filter from being clogged, and extends the operative time of the filter.

Abstract: A burner which prevents obstruction by combustion products has a circularly concentric multi-tube construction of three or more tubes, comprising a central tube which emits a liquid containing a chemical element that forms a solid oxide by combustion or flame hydrolysis, a first outer tube disposed concentrically outside the central tube for emitting a combustion-supporting gas and/or a non-combustible gas, a second outer tube disposed concentrically outside the first outer tube for emitting a combustion-supporting gas and/or a non-combustible gas, and optionally, a passage disposed outside the second outer tube for supplying a combustion-supporting gas and/or a non-combustible gas. The liquid emitted from the central tube is atomized and burned by the combustion-supporting gases and/or non-combustible gases supplied from the outer tubes and the optional passage disposed outside thereof.