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.

A method for detecting an air flow distribution in a blast furnace, taking into account a heat exchange between an air flow and a solid material bed and the effect of a distribution of a material layer structure in a radial direction of a blast furnace on the radial air permeability of blast furnace, which affects a mode of air flow distribution, wherein the distribution of the air flow and the radial material layer structure of the blast furnace can be calculated by combining a cross-shaped temperature-measuring gun and other main blast furnace operating parameters. According to the detection method, a blast furnace operator can timely and accurately infer, from a change in a current radial air flow temperature distribution, the direction of change of the distribution of the air flow and the radial material layer structure at a furnace throat portion.

System and method for producing steel is provided that efficiently reduce carbon dioxide emissions. A steel production system includes: a first gas generating section configured to obtain a first gas by converting carbon monoxide, to carbon dioxide, in a gas containing the carbon dioxide and carbon monoxide; a reducing gas supply section 3 configured to supply a reducing gas containing a reducing substance to reduce a reducing agent, the reducing agent containing metal oxide to reduce carbon dioxide and being oxidized by contact with the carbon dioxide; and a reaction section 4 including a plurality of reactors 4a and 4b, respectively connected to at least one of the first gas generating section and the reducing gas supply section 3, and the reducing agent arranged in the reactors 4a and 4b, the reaction section being capable of switching between the first gas and the reducing gas to be supplied to each of the reactors 4a and 4b, wherein a second gas is configured to be supplied to a blast furnace, the second gas being obtained by contacting the first gas supplied to the reactors 4a and 4b with the reducing agent to convert the carbon dioxide to carbon monoxide and the second gas having the carbon monoxide as a main component.

Provided is a blast-furnace operating method including: a first step of adjusting a charging rate of coke while monitoring a furnace-top temperature T.sub.top; a second step of adjusting an injection rate of pulverized coal while monitoring an in-furnace superficial gas velocity u and the furnace-top temperature T.sub.top; a third step of adjusting an oxygen-enrichment ratio of oxygen-enriched air while monitoring a tuyere combustion temperature T.sub.f and the furnace-top temperature T.sub.top; and a fourth step of determining whether an injection rate of the oxygen-enriched air needs to be adjusted, based on a value of the in-furnace superficial gas velocity u.

A method and system for operating a seal gas compressor utilized in a direct reduction process including: monitoring a pH level of a water stream used in the seal gas compressor, wherein the pH level of the water stream is affected by a reformer flue gas stream that comes into contact with the water stream, wherein the monitoring step is carried out one or more of upstream of the seal gas compressor and downstream of the compressor; and adjusting the pH level of the water stream to maintain the pH level of the water stream within a predetermined range based on feedback from the monitoring step. The method includes maintaining the pH level of the water stream upstream of the seal gas compressor in a range between 7.5 and 10 and maintaining the pH level of the water stream downstream of the seal gas compressor in a range between 7.8 and 9.5.

An object is to measure the fine ratio, or the ratio of fines adhering to the surface of lumps of material, in real time with high accuracy.

A fine ratio measuring method includes a step S1 of measuring a distance between a distance measuring device and lumps of material, a step S2 of calculating a feature quantity from distance data obtained in the step S1, and a step S3 of converting the feature quantity calculated in the step S2 to a fine ratio. The feature quantity calculated in the step S2 represents distance variation calculated from the distance data obtained in the step S1. A higher fine ratio in lumps of material means greater microscopic distance variation caused by microscopic irregularities in the surface of the lumps of material in the height direction within a three-dimensional shape. Therefore, by using the distance variation as the feature quantity, the fine ratio in the lumps of material can be measured in real time with high accuracy.

A method for a blast furnace includes pulverizing coal to make pulverized coal, and pulverizing iron ore to make pulverized iron ore, and injecting the pulverized coal and the pulverized iron ore from a tuyere. A loss on ignition of the iron ore is greater than or equal to 9% by mass and less than or equal to 12% by mass, an injection rate of the pulverized coal is greater than or equal to 150 kg/tp, and an injection rate of the pulverized iron ore is greater than or equal to 2.5 kg/tp and less than or equal to 50.0 kg/tp.

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.

A method for operating a blast furnace, including collecting a blast furnace gas from the blast furnace, the blast furnace gas being a CO.sub.2 containing gas, combining the blast furnace gas with a fuel gas to obtain a gas mixture, the fuel gas being a hydrocarbon containing gas, subjecting the gas mixture to a reforming process, thereby producing a synthesis gas containing CO and H.sub.2; and feeding at least a portion of the synthesis gas and an oxygen-rich gas into the blast furnace, where the blast furnace gas is combined with the fuel gas while containing substantially the same amount of CO.sub.2 as when exiting the blast furnace and wherein the blast furnace gas is combined with the fuel gas in an over-stoichiometric ratio, so that the synthesis gas contains a surplus portion of the blast furnace gas.

A method for controlling a hot metal temperature, includes: a first control loop for calculating a target value of pulverized coal ratio such that a hot metal temperature, predicted by a physical model that is able to calculate conditions inside a blast furnace, falls within a preset target range; and a second control loop for calculating pulverized coal flow rate manipulation quantity to compensate for a deviation between the pulverized coal ratio target value and a current pulverized coal ratio actual value.