Abstract: There is provided a denitrification apparatus capable of reducing NOx from a combustion facility and preventing evaporation of a reducing liquid in a lance and an injection nozzle in the combustion facility in operation at a low load by adjusting concentration of a reducing agent, thereby achieving complete evaporation of the reducing liquid in an exhaust gas duct.

Abstract: [Problem] To provide a classification device in which product fine powder little in mixture ratio of coarse particles can be obtained. [Means] for Resolution A classification device characterized in that a setting pitch P between stationary fins 13 and a width L of each stationary fin 13 are combined so that a value of P/L is in a range between 0.042×(??50)+0.64 and 0.019×(??50)+0.22 in 50°???70° when ? is an inclination angle of each stationary fin 13, P is the setting pitch, and L is the width in a direction of circulation of particles.

Abstract: An alloy prepared by reducing the sulfur content of ASTM UNS N06600 (Trademark Inconel Alloy 600) to an extremely small value and adding specified amounts of Nb and N, and an alloy prepared by reducing the oxygen content of Inconel Alloy 600 and adding specified amounts of Nb, N, B and Mg show a mechanical strength equivalent or superior to that of Inconel Alloy 600 and excellent hot workability, and further has intergranular corrosion resistance and integranular stress corrosion cracking resistance which are far more excellent than those of Inconel Alloy 600.

Abstract: A narrow weld-groove welding process, in which a bare welding wire is fed into a weld groove defined between the opposed surfaces of two pieces of metals for producing a metal arc therein for welding. In this process, a welding wire is subjected to a plastic deformation of a wave form, before being fed into a nozzle hole provided in a contact tip, and then the wire is fed into a nozzle hole, while maintaining elasticity tending to cause waving, whereby the tip of a welding wire being fed through a nozzle exit is automatically waved between the opposed surfaces of metals to be joined, with the tip of wire being alternately faced in the opposite directions, in response to the weaving motion thereof, with the feeding of the welding wire and progress of welding. In addition, the apparatus for use in a narrow weld-groove welding process is also disclosed.