Abstract: This raw material supply device supplies a raw material for producing glass fine particle deposits, to a burner and includes a raw material tank; a liquid raw material pipe having one end thereof connected to the raw material tank; a liquid raw material pressure feed pump that pumps siloxane, being a liquid raw material, from the raw material tank via the liquid raw material pipe; a pressure adjustment valve provided on a secondary side of the liquid raw material pressure feed pump in the liquid raw material pipe; an MFC for liquid, connected to the other end of the liquid raw material pipe; and an aeration device that is connected to the secondary side of the MFC for liquid and aerates the liquid raw material. The pipe on the secondary side of the pressure adjustment valve is connected to a location having lower pressure than the primary side pressure.

Abstract: A glass rod manufacturing device includes: a holding portion configured to hold one end of a starting rod; a heating portion configured to heat a bent portion; and a centering jig configured to apply a force in a first direction intersecting an axis to a part of the starting rod that whirls between the bent portion and another end of the starting rod due to rotation of the starting rod about an axis. The centering jig includes: an abutment portion configured to abut against the part; an elastic displacement portion configured to elastically displace the abutment portion in the first direction according to a run-out deviation of whirl of the part; and a slide portion configured to slide the abutment portion in a second direction intersecting the axis and the first direction according to the run-out deviation of whirl of the part.

Abstract: Provided is a device for producing a fine glass particle deposited body by depositing fine glass particles on a starting rod disposed within a reaction vessel, the device being provided with: a burner for synthesizing fine glass particles by jetting out a source gas; a transfer mechanism to which the burner is disposed and which causes the burner to move backward in association with an increase in the diameter of a fine glass particle deposited body; a vaporizer which is disposed to the transfer mechanism so as to be moved backward integrally with the burner and which converts a liquid siloxane into a source gas through vaporization; piping through which the source gas is fed from the vaporizer to the burner; and a heating mechanism which heats up the piping with a heating temperature of at least 230° C.

Abstract: This raw material supply device supplies a raw material for producing glass fine particle deposits, to a burner and includes a raw material tank; a liquid raw material pipe having one end thereof connected to the raw material tank; a liquid raw material pressure feed pump that pumps siloxane, being a liquid raw material, from the raw material tank via the liquid raw material pipe; a pressure adjustment valve provided on a secondary side of the liquid raw material pressure feed pump in the liquid raw material pipe; an MFC for liquid, connected to the other end of the liquid raw material pipe; and an aeration device that is connected to the secondary side of the MFC for liquid and aerates the liquid raw material. The pipe on the secondary side of the pressure adjustment valve is connected to a location having lower pressure than the primary side pressure.

Abstract: This burner for producing a fine glass particle deposited body is provided with a metallic gas-feed pipe that forms a burner body, and a cover for covering the gas-feed pipe, wherein: the gas-feed pipe and the cover are integrally formed; the gas-feed pipe has connected thereto a piping through which material gas, oxyhydrogen gas, and seal gas are supplied; and the cover covers, in the axial direction of the burner over a prescribed length and in a given constant outer diameter, the gas-feed pipe and a connection part of the piping connected to a lateral surface of the gas-feed pipe.

Abstract: A method for producing a glass particulate deposit, said method comprising using siloxane as a raw material for glass, discharging the siloxane gasified in a vaporizer and a combustion gas from a burner and combusting, and thus forming a glass particulate deposit in a reaction vessel, wherein: after producing a good section of the glass particulate deposit, the supply of the siloxane that is the raw material for glass to the burner is ceased while continuously supplying the combustion gas to the burner; then the glass particulate deposit is taken out from the reaction vessel; a raw material gas port from the vaporizer to the burner is purged by flowing an inert gas therethrough; and, when a color derived from the combustion of the siloxane gas is not observed any more in the flame of the burner, then the supply of the combustion gas is ceased.

Abstract: A water treatment device includes a filter that is rotatable so that a filtering surface moves in a circumferential direction; an untreated-water outflow unit that allows untreated water to flow out from an outside of the filter toward the filtering surface; a filtered-water flow path for leading, from an inside of the filter, filtered water that has permeated through the filter; and a control unit that switches between a filtration operation in which, in a state where the filter rotates, the untreated water is allowed to flow out toward the filtering surface by the untreated-water outflow unit, and the filtered water is led through the filtered-water flow path, and a cleaning operation, in which, in a state where the filter rotates and the filtered-water flow path is closed, the untreated water is allowed to flow out toward the filtering surface by the untreated-water outflow unit.

Abstract: The sealing component 1 of the invention is provided with a metallic housing 19 that comprises a base part 19a, a side wall 19b connected to the base part 19a and an opening portion 19c facing to the base part 19a, and a metallic lid 20 to cover the opening portion 19c, wherein a melted portion 24 is formed around the boundary between the lid 20 and the upper edge 19b1, the melted portion 24 is formed to reach the corner 19b3 of the side wall 19b, and the melted portion 24 has a convexly-curved outward form 24a from the top face of the lid 20 to the corner 19b3 in the longitudinal cross-sectional view of the sealing component 1.

Abstract: The sealing component 1 of the invention is provided with a metallic housing 19 that comprises a base part 19a, a side wall 19b connected to the base part 19a and an opening portion 19c facing to the base part 19a, and a metallic lid 20 to cover the opening portion 19c, wherein a melted portion 24 is formed around the boundary between the lid 20 and the upper edge 19b1, the melted portion 24 is formed to reach the corner 19b3 of the side wall 19b, and the melted portion 24 has a convexly-curved outward form 24a from the top face of the lid 20 to the corner 19b3 in the longitudinal cross-sectional view of the sealing component 1.

Abstract: A molding die 1 is constituted by an upper die 1a and a lower die 1b which are made of a material transparent to an ultraviolet light, and has a cavity 3 constituted by grooves 2c, 2d, whereas a resin injection gate 4 and a resin exit gate 7 are provided so as to communicate with the cavity 3. A junction of an optical fiber 10 is inserted into the cavity 3. A UV-curable resin is injected into the cavity 3 surrounding an exposing portion of the glass optical fiber 11 from the resin injection gate 4 positioned at one of coating ends of the optical fiber 10, whereas a part thereof is discharged from the resin exit gate 7 positioned at the other coating end. The ultraviolet light is emitted through the lower die 1b so as to cure the resin, thereby forming a reinforcement resin coating. As a consequence, bubbles can be prevented from occurring due to the residual air within the reinforcement resin coating in the junction of the optical fiber 10.

Abstract: Provide are safe equipment and method, in which gas leakage through junction part between a furnace muffle tube and a lid can be restrained, for manufacturing a high quality glass preform. The equipment for manufacturing a glass preform comprises (1) a furnace muffle tube in which a soot glass deposit body is placed, (2) a lid for sealing up an inlet-outlet opening of the furnace muffle tube, and (3) a heater for heating the soot glass deposit body. The method of producing a soot glass deposit body comprises steps of (1) placing a soot glass deposit body into a furnace muffle tube, (2) sealing up the inlet-outlet opening of the furnace muffle tube with a lid, (3) heating the soot glass deposit body so as to vitrify it into a transparent glass body. In these equipment and the method, the surface roughness in the respective junction surfaces of the furnace muffle tube and the lid is 1.

Abstract: Stress exerted on an inner or outer circumferential side of a glass tube 6 is controlled when a glass material 3 is heated and softened by a heating element 41 provided around the glass material 3 and a piercing plug 31 is relatively pressed into a softened region of the glass material 3 to thereby form the glass material 3 into the glass tube 6 gradually. For example, the control of the stress can be carried out by controlling an internal or external pressure of the glass tube 6. As a result, the deformation of the glass tube 6 just after piercing is prevented so that the glass tube 6 can be obtained with high quality. It is also possible to solve the problem that cracks may occur easily at the time of reheating because of residual stress distribution after cooling.

Abstract: A method for handling a fusion-spliced optical fiber and a transferring jig for transporting the optical fiber are provided. The jig is capable of holding the fusion-spliced optical fiber in a state in which a given tension is applied at the spliced portion, and stopping the application of such tension if needed. The jig is easy to transport and set to each of separate processing processes. In the method, a fusion-spliced optical fiber is clamped at coated portions thereof on both sides of the fusion-spliced portion by a pair of clamps of the jig and transported by the jig holding the optical fiber in a state wherein a given tension is applied thereto through the clamps.

Abstract: An object is to provide an optical fiber fusion splicing method in which splice loss can be reduced, and also to provide an arc-heating unit used for heating the fusion spliced part of an optical fiber. The method comprises a process of fusion-splicing together the end faces of two optical fibers and a process of continuously heating the fusion spliced part by arc while moving one pair of electrodes provided opposite to each other across the fusion spliced part. The arc heating process is performed with the operation for decreasing arc temperature.

Abstract: An object of the present invention is to provide a method of highly purifying a glass body, which enables high purification of the glass body while decreasing deformation of the glass body at a high degree, to provide a highly purified glass body, and to provide a method and an apparatus for manufacturing a glass tube, which can obtain a highly purified glass tube. A method of highly purifying a glass body according to the present invention is to apply a voltage between electrodes 1 and 2, which make contact with the glass pipe 11, in a nearly radial direction of the glass pipe 11 while heating the glass pipe 11 to a temperature within a range less than 1300° C.

Abstract: A method of fusion-splicing optical fibers having different mode field diameters or small mode field diameters is provided, which method is advantageous in that the splicing loss is smaller. The method comprises a fusion splicing process in which fusion splicing is performed by butting end faces of two optical fibers together and a heat treatment process in which the fusion spliced part of the optical fibers and the vicinity thereof are heated. The heat treatment process is performed by moving an arc heating unit in a direction other than the Y-axis direction (a direction perpendicular to the Z-axis direction and the opposing direction of arc electrodes) and Z-axis direction (the axial direction of the optical fiber), via the fusion spliced part in a Y-Z plane formed by the Y-axis direction and Z-axis direction.

Abstract: Stress exerted on an inner or outer circumferential side of a glass tube 6 is controlled when a glass material 3 is heated and softened by a heating element 41 provided around the glass material 3 and a piercing plug 31 is relatively pressed into a softened region of the glass material 3 to thereby form the glass material 3 into the glass tube 6 gradually. For example, the control of the stress can be carried out by controlling an internal or external pressure of the glass tube 6. As a result, the deformation of the glass tube 6 just after piercing is prevented so that the glass tube 6 can be obtained with high quality. It is also possible to solve the problem that cracks may occur easily at the time of reheating because of residual stress distribution after cooling.

Abstract: A method of producing with the collapsing process an optical fiber preform capable of forming an optical fiber in which an increment in transmission loss due to OH absorption is reduced, and an optical fiber preform and an optical fiber produced with the method. The method comprises reducing the amount of hydrogen atom-containing substances in a glass pipe, sealing one end of the glass pipe, and collapsing the glass pipe to obtain a solid body. One aspect of the method comprises heating the glass pipe at 550° C. or below, sealing one end of the glass pipe, and collapsing the glass pipe to obtain a solid body. The preform produced with the method has a feature in that its portion formed by the interface portion at the time of the collapsing contains OH groups at a concentration of 100 wt. ppb or below. The optical fiber produced by drawing the preform has a feature in that its OH-originated loss is less than 0.5 dB/km at a wavelength of 1.38 &mgr;m.

Abstract: The present invention relates to a method of making a glass tube. In the method, a diameter expanding member is inserted through a hole in a tubular glass blank so as to expand the diameter of the hole while the temperature of the glass blank is controlled to be more than or equal to the softening point. The tubular glass blank may be a purchased product or a self-made product. In the above-mentioned method of making a glass tube, the diameter of the hole in the glass blank may be expanded while at least the rear end of the diameter expanding member is supported. The diameter of the hole in the glass blank may be expanded while both ends of the diameter-expanding member are supported. The present invention also relates to an apparatus for manufacturing a glass tube.

Abstract: A method for handling a fusion-spliced optical fiber and a transferring jig for transporting the optical fiber are provided. The jig is capable of holding the fusion-spliced optical fiber in a state in which a given tension is applied at the spliced portion, and stopping the application of such tension if needed. The jig is easy to transport and set to each of separate processing processes. In the method, a fusion-spliced optical fiber is clamped at coated portions thereof on both sides of the fusion-spliced portion by a pair of clamps of the jig and transported by the jig holding the optical fiber in a state wherein a given tension is applied thereto through the clamps.