Terminology
Sinter plant
An operation processing iron ore which is along with coal the basic raw material for steel making. The iron ore is being clinkered into sinter.
BAT
Best Available Techniques
Benzo(a)pyren
Polycyclic aromatic hydrocarbon with five benzo(a)pyren circles. It is generated by insufficient burning at temperatures between 300 - 600 °C.
Dioxins
Organic compounds with chlorine content. They are products of insufficient chlorine substance burning. They can originate during natural processes too e.g. fires or eruptions. Dioxins are part of waste generated at blast furnaces and steel plant. We hand it over to a company authorized to handle this kind of waste.
Emissions
Polluting matters which are discharged from certain sources (exhaust pipes or factory’s and household chimneys) into the air. They are measured directly at the source.
Emission limit
The highest acceptable amount of polluting matters discharged from a certain source into the air. This limit is set in the Air protection act.
Emission ceiling
The highest acceptable total amount of polluting matter emission at a given spot over certain period of time. The emission ceiling is set in the integrated permit issued by the Regional Authority.
Power supply
AMEO (Liberty Energy Ostrava) – power plant and heating plant at the steel mill.
Pollutants
General quality of the air at a certain place which besides all other pollution sources is also impacted by disperse conditions or a geographical location. The amount of polluters which accumulate in the environment. Pollutants are consequences of emissions. Their concentration is lower and stable.
Pollutant limit
The highest acceptable level of pollution expressed in pollutant weight units per air volume unit during a normal air pressure and temperature.
Integrated permit
A document specifying emission limits for individual operations of industrial companies (it replaces several separate permits). It is issued by the Regional Authorities.
Coke plant
One part of a steel mill producing coke out of coal which along with the processed iron ore (see sinter plant) represents the basis of a blast furnace charge where pig iron is produced.
Best available techniques (BAT)
The most effective and advanced stage of technology development and asset operation which are suitable for prevention or emission reduction and their environmental footprint. These techniques are required by the European Union legislation which are effective since 2016.
Steel plant
It’s a part of a steel mill where the final production of steel from pig iron take place.
Sulfur dioxide
A colourless gas produced especially during sulfur burning. In nature it appears in volcano gases.
Dust particles PM 1, PM 2,5 and PM 10
Solid dust particles. They differ in size (fraction) – PM 10 are particles whose aerodynamic diameter does not exceed 10 µm etc.
Medium section mill
It’s a plant producing medium and fine steel section intended especially for buildings and constructions.
Bag filter
The best available technique for dedusting which collects even the smaller solid particles. They go through long fabric tubes which capture them. The tubes are shaken off on a regular basis and the particles are transferred into a silo. The bag filter represents BAT for dedusting.
Blast furnaces
It’s an operation where pig iron is produced. Then it goes on to steel plant where steel is made.
Blowing
The power plant boiler cleaning which follows major technological boiler adjustments e. g. after an environmental investment. Generated steam is used for cleaning the boiler through blowing. Throughout the blowing process the pressurized hot steam is discharged through interim pipelines into the air and pushes dirt out of the boiler e.g. remnants after welding.
All about blowing or when power plant cleans up its boiler
Why blowings are done?
The blowings or the boiler cleanings are always carried out in accordance with national standards after a major boiler adjustment. Operationally it is a very important part of the boiler launch – before commissioning it cleans up to a maximum level thanks to the blowings. The boiler needs to be clean before launch so that it does not blow impurities into the turbine. The mechanical impurities e.g. welding remnants, could make irreversible harm to the turbine and stop the whole energy production.
We carry out the blowings at the steel industry power plant because we successfully draw near to three boiler commissioning which are newly equipped with an environmental technology to reduce NOx emissions. How is such a blowing done?
The boiler cleaning is carried in two phases – first the boiler is cleaned by a chemical flush then comes the mechanical cleaning done by pressurized hot steam so called blowing. The boiler is set on full power, the generated steam is summoned and heated up then it is discharged through pipelines into the air. The blowing itself takes about 30-60 minutes and it releases up to 200 tons of steam! The steam represents clean water which takes the remaining impurities out of the boiler – e.g. welding remnants. The heat-up phase before the blowing itself takes about two hours and the cooling phase about an hour.
How many blowings have to be made?
The number of blowings is determined by the cleaning efficiency, at least three of them have to be made. In each blowing the size and number of mechanical impurities is detected. When the boiler is considered clean the blowings come to an end.