Abstract: The ammonia synthesis system of the present invention includes an ammonia synthesis reaction unit (10) that synthesizes ammonia from nitrogen and hydrogen; an ammonia cooler (20) that cools an ammonia-containing gas discharged from the ammonia synthesis reaction unit (10); a gas-liquid separator (30) that separates ammonia liquefied by the ammonia cooler (20) from a circulated gas; and an ammonia synthesizing gas supplying unit (40) that supplies nitrogen gas and hydrogen gas, the circulated gas being supplied to the ammonia synthesis reaction unit, the circulated gas supplied to the ammonia synthesis unit having an ammonia gas concentration of 3% by volume or more. The method for producing ammonia of the present invention includes reacting nitrogen and hydrogen using a circulated gas having an ammonia gas concentration of 3% by volume or more and using an ammonia synthesis catalyst under a condition of a reaction pressure of 10 MPa or less to produce ammonia.

Abstract: The present invention relates to a method of examining an aperture diameter of a disk substrate having a circular aperture in the central portion thereof, the method including: attempting to pass a standard sphere for the aperture diameter through the aperture; and inspecting the aperture diameter of the disk substrate, based on whether the sphere passes through the aperture or not. Furthermore, the present invention relates to an examination apparatus thereof.

Abstract: The present invention relates to a method of examining an aperture diameter of a disk substrate having a circular aperture in the central portion thereof, the method including: attempting to pass a standard sphere for the aperture diameter through the aperture; and inspecting the aperture diameter of the disk substrate, based on whether the sphere passes through the aperture or not. Furthermore, the present invention relates to an examination apparatus thereof.

Abstract: A shell-and-tube apparatus, more specifically, a shell-and-tube reactor, which includes a vessel, at least one intermediate tube plate sectioning the interior of the vessel into at least two compartments having different temperatures, a number of heat transferring tubes penetrating the intermediate tube plate or plates, and a fluid passing through the tubes which is heated or cooled by a heat transfer medium surrounding the tubes. At least one insulation plate or plates are provided on one or both sides of the intermediate tube plate so that the space between the intermediate tube plate or plates and, if two or more insulation plates are used, the space or spaces between the insulation plates may be utilized as a stagnation zone for the heat transfer medium, so as to make the temperature gradient through the intermediate tube plate or plates gentle and relax the thermal stress occurring in the body wall.

Abstract: A laser-light shield including a metallic substrate having uneven surface and a flame-sprayed film formed on the uneven surface and essentially consisting of metal oxide. The shield is useful for shielding a human body from laser light.

Abstract: A process for converting solid wastes to gases suitable for use as a town gas comprising the steps of (1) pyrolyzing solid wastes at 550.degree. C. or higher in a pyrolyzing furnace to produce pyrolysis gases containing hydrogen, carbon monoxide and dioxide, methane and other hydrocarbons as well as chlorine-containing compounds, sulphur-containing compounds and other impurities, (2) washing the pyrolysis gases with an aqueous alkaline solution or the like, (3) refining the washed pyrolysis gases with the hydrogen contained in the pyrolysis gases, (4) reforming the refined pyrolysis gases by steam reforming, CO conversion and/or methanation and (5) separating the excess steam and carbonic acid gas from the reformed gases. In one embodiment, the washing (2) and refining (3) may be substituted by the high-temperature steam reforming of the pyrolysis gases in hot state supplied directly from the pyrolyzing furnace.

Abstract: Terephthalic acid produced by oxidizing paraxylene can be obtained in the form of dried powder from the slurry containing terephthalic acid and acetic acid and/or water by using combination of a tubular type heater having at least one heating tube and a separation chamber in which the heating tube(s) open(s) at one end(s) thereof.Critical slurry concentrations for smooth operation are given.

Abstract: Reaction mother liquor of terephthalic acid production is treated to separate volatile component mainly composed of acetic acid and solid components composed of used catalyst or heavy metal salt(s), residual terephthalic acid and reaction by-products by using combination of a tubular type heater having at least one heating tube of a relatively small diameter and a separation chamber in which the heating tube(s) open(s) at one end thereof.