Blast furnace plant (1) and shutdown process for such a blast furnace plant (1). The blast furnace plant comprises a blast furnace (2) and a gas cleaning section (6) for cleaning gas from the blast furnace. Clean gas is released via a clean gas vent line (11) downstream of the gas cleaning section.

According to a certain viewpoint of the present invention, there is provided a blast furnace operation method comprising blowing a high-concentration hydrogen-containing gas containing 80 mol % or more of hydrogen gas from a tuyere under: a condition in which a blowing temperature of the high-concentration hydrogen-containing gas is room temperature or higher and 300° C. or lower and a gas volume of the hydrogen gas in the high-concentration hydrogen-containing gas is 200 Nm.sup.3/t or more and 500 Nm.sup.3/t or less; a condition in which the blowing temperature of the high-concentration hydrogen-containing gas is higher than 300° C. and 600° C. or lower and the gas volume of the hydrogen gas in the high-concentration hydrogen-containing gas is 145 Nm.sup.3/t or more; a condition in which the blowing temperature of the high-concentration hydrogen-containing gas is higher than 600° C. and 900° C. or lower and the gas volume of the high-concentration hydrogen-containing gas is 125 Nm.sup.3/t or more, or the like.

A method for operating a blast furnace with which, even in the case where there is an increase in the powder ratio of coke to be charged into the blast furnace, it is possible to achieve the stabilization of blast furnace operation. The method includes blowing air through a tuyere disposed in a lower part of the blast furnace, successively measuring a particle size distribution of coke transported to the blast furnace, and adjusting at least one of a blast volume and a coke ratio in accordance with an index derived from the particle size distribution.

A gas scrubber cone condition monitoring system has a sealed gas scrubber cone (9) moveably mounted in a gas pipe (1), a collar (5) fixedly mounted radially outward of the cone in the gas pipe and a pressure tap (12) into the sealed cone. The pressure tap is coupled to a condition monitor (17,18) via an input line (16). An output line (14) from the condition monitor is coupled to a gas pipe (15), downstream of the sealed cone. The condition monitor includes at least one of a pressure gauge and a gas flow meter.

The invention relates to a blast furnace plant (1, 1a-1c) with a blast furnace (2) and a charging device (3) for the blast furnace (2). In order to provide an economical way of providing clean gas to the charging device, the invention provides that the blast furnace plant (1, 1a-1c) further comprises: at least one nozzle (6) for introducing a clean gas into said charging device (3); a cleaning device (7) which is connected for receiving gas from the blast furnace (2) and arranged for removing dust from the gas; at least one compressor (9) arranged for receiving gas from the cleaning device (7), compressing the gas and feeding the gas to the at least one nozzle (6); and at least one turbine (8) connected for receiving and being driven by gas from the blast furnace (2), the at least one turbine being mechanically coupled to drive the at least one compressor (9).

A blast furnace fault determination apparatus includes a processor configured to: calculate a fault index indicative of a degree of fault in a blast furnace; calculate a ventilation index of the blast furnace; and determine a fault condition in the blast furnace using the fault index and the ventilation index.

Disclosed are methods useful in applications relating to blast furnace processes. The methods of the present invention provide enhanced deposition inhibition of particulate matter in top-pressure recovery turbines. The methods of the present invention comprise adding nitrogen-containing compounds to a top-pressure recovery turbine, inhibiting deposition of solids formed from blast furnace gas on top-pressure recovery turbine components.

A gas scrubber cone condition monitoring system has a sealed gas scrubber cone (9) moveably mounted in a gas pipe (1), a collar (5) fixedly mounted radially outward of the cone in the gas pipe and a pressure tap (12) into the sealed cone. The pressure tap is coupled to a condition monitor (17, 18) via an input line (16). An output line (14) from the condition monitor is coupled to a gas pipe (15), downstream of the sealed cone. The condition monitor includes at least one of a pressure gauge and a gas flow meter.

Disclosed are methods useful in applications relating to blast furnace processes. The methods of the present invention provide enhanced deposition inhibition of particulate matter in top-pressure recovery turbines. The methods of the present invention comprise adding nitrogen-containing compounds to a top-pressure recovery turbine, inhibiting deposition of solids formed from blast furnace gas on top-pressure recovery turbine components.