The invention relates to an optical monitoring system (26) for monitoring operating conditions in a tuyere zone of a blast furnace. This system comprises a light deflecting device (40) with a peep sight (28) arranged in a first face (46) of the light deflecting device (40) and an optical sensor (30) arranged in a second face (48) of the light deflecting device (40). A light deflector (41) is arranged within the light deflecting device (40) for directing incident light from the tuyere zone towards the peep sight (28) and towards the optical sensor (30). The light deflecting device (40) comprises a housing (56) with a spherical body (60) rotatably arranged therein. The spherical body (60) comprises three passages: a first passage (62) which is, when the light deflecting device (40) is connected to the rear portion of the blowpipe (18), facing the tuyere for allowing incident light from the tuyere zone to enter the spherical body (60); a second passage (70) facing the peep sight (28); a third passage (72) facing the optical sensor (30). The first, second and third passages (62, 68, 72) are configured so as to meet each other within the spherical body (60). The light deflector (41) is arranged within the spherical body (60) at the intersection of the first, second and third passages (62, 68, 72). Furthermore, the light deflecting device (40) comprises an opening (76) in a third face (50) of the housing (56) for accessing the spherical body (60) for allowing rotation of the spherical body (60) within the housing (56). The spherical body (60) comprises a socket (78) facing the opening (76) in the third face (50). The opening (76) is a guiding slot (86) whose width is substantially the same as a diameter of the socket (78).

To provide a method for operating a blast furnace with which the combustion efficiency of a solid fuel, such as pulverized coal, is improved, thereby making it possible to improve productivity and reduce CO.sub.2 emissions. Pulverized coal and oxygen are blown from an upstream lance 4 configured by a double tube, and LNG is blown from a downstream lance 6 on the downstream side in a hot air blast direction, so that oxygen to be used for combustion of the LNG is supplied from the upstream lance 4, and the pulverized coal whose temperature has been increased by the combustion of the LNG is combusted along with the supplied oxygen or oxygen in an air blast. When a direction perpendicular to the hot air blast direction is designated as 0, and a downstream direction and an upstream direction therefrom in the hot air blast direction are designated as positive and negative, respectively, a blowing direction of the LNG from the downstream lance 6 with respect to the blast direction ranges from 30 to +45, and a blowing position of the LNG from the downstream lance 6 with reference to a position at which the upstream lance 4 is inserted into a blast pipe 2 ranges from 160 to 200 in terms of a blast pipe circumferential direction angle.

The invention relates to an oxygen lance that has at least three mutually coaxial pipes, each of which delimits at least one annular gap. The outermost pipe is designed to conduct superheated steam and has a steam supply point, the central pipe is designed as an annular gap, and the innermost pipe is designed to conduct oxygen at a temperature of no higher than 180 C. and has an oxygen supply point. A temperature sensor is arranged within the innermost pipe, said temperature sensor extending to just in front of the opening of the innermost pipe. The innermost pipe tapers in the form of a nozzle before opening; the innermost pipe opens into the central pipe; and the opening of the central pipe protrudes farther relative to the opening of the outermost pipe.

An injection regulation and control device includes blast furnace tuyeres for introducing rich oxygen or pure oxygen to form tuyere raceways. Temperature-adjusting injection openings are evenly formed in the circumferential direction of a blast furnace and inject a hydrocarbon component-containing injection object to the blast furnace. The temperature-adjusting injection openings are located, in an axial direction, within a height range where a soft melting dripping zone is located and are not lower than the positions of the blast furnace tuyeres. The hydrocarbon component-containing injection objects are enabled to undergo a thermal cracking reaction by utilizing the temperature in the vicinity of the tuyere raceways to form a hydrocarbon thermal cracking heat absorption area. Gas products generated by the thermal cracking reaction of the hydrocarbon component-containing injection objects increase the blast furnace gas volume. Redundant heat in a lower high-temperature area is carried to the upper part of the blast furnace.

A cupola furnace includes at least one tuyere opening into an interior of the cupola; and at least one oxygen stream and at least one natural gas (NG) stream in fluid communication with said at least one tuyere for providing oxygen and NG to the cupola furnace interior. A related method is also provided for heating a cupola furnace, and includes introducing at least one oxygen stream and at least one NG stream into the cupola furnace for reaction therein.

A method of operating a blast furnace includes two or more lances that inject reducing agents from a tuyere; injecting a solid reducing agent and a flammable reducing agent from different lances; and disposing the lances so that an axial line that extends from an end of the lance that injects the solid reducing agent and is the axial line of the lance that injects the solid reducing agent and an axial line that extends from an end of the lance that injects the flammable reducing agent and is the axial line of the lance that injects the flammable reducing agent cross each other, and so that a main flow of the solid reducing agent injected and a main flow of the flammable reducing agent injected overlap.

A blast furnace blower device includes a body, a flow guidance structure and a cooling module. The body is hollow inside. The body includes an inlet area, an outlet nozzle area, and a fuel nozzle area. The fuel nozzle area is located between the outlet nozzle area and the inlet area, and a channel is formed from the inlet area to the outlet nozzle area. The flow guidance structure is deployed continuously or discontinuously along an inner wall of the body. The flow guidance structure is located between the fuel nozzle area and the outlet nozzle area. The flow guidance structure has a nozzle distance range along an axial direction of the body to the outlet nozzle area. The cooling module is located outside the body.

A method of heating up a furnace bottom and a burner lance used in the method are proposed. The method of heating up the furnace bottom includes a step of opening, in the tap hole, a burner lance insertion hole having a diameter larger than a diameter of the burner lance so as to penetrate into the furnace, a step of installing the burner lance in the opened burner lance insertion hole, a step of filling a gap between the installed burner lance and a furnace exterior side of the tap hole with a refractory, and a step of blowing in gas for heating into the furnace from the burner lance to heat up the furnace bottom.

A blast furnace includes: a blast furnace body; raw material charging means for charging raw material into the blast furnace body; hot air blowing means for blowing hot air into the blast furnace body; a drying apparatus etc. for evaporating moisture in low-grade coal; a dry distillation apparatus etc. for carbonizing dried coal; a cooling apparatus etc. for cooling carbonized coal; a pulverization apparatus etc. for pulverizing the carbonized coal cooled by the cooling apparatus; a storage tank for storing powdered coal; a nitrogen gas supply source, a conveyor line and a cyclone separator etc. for conveying the powdered coal pulverized by the pulverization apparatus to the inside of the storage tank by generating a gas flow with the nitrogen gas; and an injection lance etc. for feeding the powdered coal inside the storage tank to hot air that is blown into the blast furnace body.

An air blast system for melting furnaces includes: a supply unit supplying hot air into a melting furnace; a bustle pipe connected to the supply unit; a tuyere stock connecting the bustle pipe to the melting furnace to supply hot air from the bustle pipe to the melting furnace in a distributed manner; and a temperature management module determining whether the tuyere stock is damaged by comparing a temperature of the tuyere stock with a preset reference temperature.