ENERGY SAVING SOLUTIONS
Today, energy and environmental issues are becoming more and more important. Finding ways to reduce fuel consumption, solving corrosion problems related to the increased use of alternative fuels and having longer life time on refractories and equipment are the top priorities nowadays. The use of high-sulphur fuels, together with poor combustion engineering, can lead to a higher sulphate compound volatilization, ring formations and build-ups. A number of factors can cause coating to disappear completely, with a resulting tendency for the brick to become weak and friable due to thermomechanical fatigue.
The challenge is to adopt the right refractory solutions that not only minimize the impact on the environment but also prevents corrosion. Anticipating the increase in prices for fossil fuels, Höganäs Bjuf has developed an energy saving refractory design.
A new refractory design for energy saving and maximum corrosion protection
The new design is based on hot face bricks for acidic atmospheres produced by Höganäs Bjuf and acid-resistant insulating bricks. The design not only saves energy, but also prevents corrosion as the bricks are alkali and chloride resistant. By combining the right material and the right installation techniques for double layer linings, the optimum design allows the brick lining to last longer.
In order to avoid corrosion of the steel shell, there are two different approaches to the design of the refractory and insulating lining:
- Installing the refractory layer requires the placement of the acid dew point temperature inside the insulating lining.
- Alternatively, the acid dew point temperature can be moved outside the steel shell (avoiding the acid gas from condensing inside the construction).
Moving the acid dew point temperature inside the insulating lining sets high demands for the materials used. They should be extremely acid resistant and especially resistant to sulfuric acid, hydrochloric and nitric acid, which are the most typical types of acids.
For more detailed information about our new refractory design, please contact us.
Solving real-life problems in Cement Industry
Top priorities for the cement industry today are to reduce fuel consumption and solve the corrosion problems related to increased usage of alternative fuels. For many cement groups the average share of alternative fuels has risen up to 50-70%. At around 55%, heavy corrosion is common.
Alkali attacks on the refractory lining
Chemical attacks in the form of alkali penetration are unavoidable in cement production. The worst damage occurs in the lower cyclone stages and riser ducts, rotary kiln inlets and even in the calciners. Alkali and acid vapors infiltrate the refractory linings and attack the binding phase at temperatures as low as 600 – 700˚C, thus endangering the lining. When these gases penetrate the insulating lining behind the refractories, the consequences are even more profound.
Chloride and sulfur, combined with condensing steam, form acids that corrode the anchors. At higher temperatures, corrosive vapors can penetrate higher up into the cyclone system, making the use of alkali and chloride-resistant refractories a necessity.
You may view our solutions of energy-saving refractories for protection against corrosion by selecting each process stage of the cement production in the following link.