In a market characterised by increasing demand, ever-growing quality expectations, and a multitude of environmental protection regulations, metal and steel producers are under huge pressure. In order to be successful in this field, the use of state of the art measurement technology is vital. This is to optimise production processes and ensure uncompromising quality.
In raw iron production
Raw iron is produced by reduction (oxygen withdrawal) of iron ore, either in a blast furnace or by direct reduction. Coke, natural gas, or coal are used as reduction materials. In the blast furnace process the prepared ore (pellets, sinter) and the additives are charged into the blast furnace from the top, together with coke.
Freshly produced steel
A hot blast flows in from below as a further energy carrier. The mixture of the hot blast and reduction gases climbs up in the opposite direction to the sinking raw materials, and is drawn off at the top as stack gas. The liquid raw iron collects on the floor of the furnace together with the slag, and is regularly drawn off and usually transported to a steel works for further processing. The composition of the stack gas during the entire process is a crucial factor, and influences the quality of the combustion in the air heaters.
In coking plants
Coking plants are thermal refinement plants for mineral coal, in which the coal is heated to at least 800 °C in dry distillation under exclusion of air (pyrolysis). The objective of this coking is the production of coke for industrial use, in particular in metallurgy.
Coke is characterized by a very high carbon content (>97 %) and only very few volatile components. During the process, coke oven gas is produced, which is used further. The coal is dry-distilled ("cooked") over approx. 15 hours in a coke oven, and then transferred to a cooling process. Traditionally wet cooling has been common practice but this has now been largely replaced by dry cooling in a slag cooler.
Tapping a blast furnace
This allows the recovery of heat via a heat recovery boiler, and a reduction of pollutant emission. Relevant pollutants which occur in coke production are, in addition to dust, above all SO 2, NOx, CO and organic components. With regards to permitted limit values, the exhaust gases are subject to the stipulations of the TA Luft, and their composition allows important conclusions to be drawn on the monitoring and optimisation of the production process.
The solution: The emission measuring instrument - testo 350
In raw iron production
With the emission measuring instrument testo 350, the components carbon monoxide (CO) and carbon dioxide (CO2) can be determined quickly and easily. The measurement is taken at the stack gas exit after the dust bag, in the blast furnace flue as a command variable for furnace operation, and in the downpipe before the dust bag for the plant balance. The testo 350 can additionally be positioned in order to prevent the danger of fire in the CO dust bag, by use of a measurement.
In coking plants
Within the coke production process, the testo 350 can be used to measure SO2, NOx (the sum of NO and NO2), CO and O2. The emission measuring instrument has six slots, and can hold five gas sensors in addition to O2. Since the CO value in the blast furnace provides information on the combustion efficiency of the furnace, it is one of the most commonly measured parameters.
CO concentrations of 50,000 ppm can be reached here, which can be measured using the testo 350 and the optimally integral dilution. The testo 350 allows you to measure and record all emission parameters easily and securely.
The testo 350 is the perfect instrument to:
Added advantages of the 350 include:
With all measurements of the above applications, you can be confident results will be precise and reliable. In addition to this, it is possible with the emission measuring instrument to visualise load changes on components as a time progression, thus preventing downtime. All in all whether producing steel, metal, or coke, the testo 350 will help to optimise both time and ultimately cost of production.