Technology
Tackling Corrosion
Published
9 years agoon
By
admin
Dip tubes used in pre-heater cyclones have a perennial problem of shorter life than expected. Chlorine induced high temperature corrosion kinetics in the preheater cyclone reduces the service life of dip tube material.
Portland cement is manufactured in a rotary kiln. The rotation of the kiln causes the raw material to gradually pass along and undergo chemical reaction from where it enters the cooler. The molten clinker gets cooled from -1300-?C to 100-?C in the cooler over a period of time. Before entering into the kiln, the blended raw material enters the pre-heater and pre-calciner, where it is preheated and calcined to around 900-?C at various stages of cyclone and calciner. The preheater and pre-calciner use the hot gases coming from the kiln outlet and through the tertiary air duct. The raw meal fed at the top of the pre-heater tower is passed through a series of cyclone and calciner. Hot gas from the kiln is admitted from bottom to top and in the process heat gets transferred efficiently from hot gas to the raw material according to the counter current principle. A typical flow diagram of preheater cyclone is given in figure 1.
Figure1: Process flow diagram of pre heater cyclone in cement plant.
40-60 per cent of the feed material is calcined at the precalciner before it enters to the rotary kiln. Alternative fuels are fired in the calciner system where it generates deleterious gases such as SOx, NOx, and Chlorides. Dip tubes are used to improve the separation and thermal efficiency of a cyclone and the deleterious gas from the pre-calciner comes in contact with dip tubes causing severe corrosion. Dip tube failures are found occurring in several cement plants and various corrosion resistant alloys have been tried to enhance the service life of the same. The corrosion is caused by Chlorine and Sulphur that are introduced to the pyro-system as impurities in the fuel and the product of reaction formed by alkali, Sulphur and Chlorine creates severe corrosion in the dip tube, thereby reducing the service life.
Figure 2: Failed central tube sample received
from cement plant.
A detailed failure investigation was carried out by collecting samples (refer figure 2) from several cement plants. The relative quantities of element of cast samples were determined by scanning electron microscope (SEM) equipped with Energy dispersed X-ray (EDX) elemental spectrometer. SEM-EDX analysis(refer to figure 3) revealed the presence of high level of Chlorine in the base metal.
Test results showed that Chlorine gas had penetrated through the protective Chromium oxide layer and has lead to the corrosion of base metal. These results were verified with the data collected from the cement plant.
Figure 3: SEM-EDX analysis of failed sample
The concentration limit of HCl in the exhaust gas is 10mg/Nm3 .However the analysis showed the presence of high amount of chlorine in the fuels which was then converted to HCl gas during combustion.
Gas containing Cl2 and HCl will cause direct corrosion by accelerating the oxidation of the metal alloy. When the dip tube is exposed to an oxidising atmosphere at high temperature, the metal will gradually oxidise to the stable oxide and form an oxide scale adjacent to the metal.
Figure 4: HCI in the flue gas
This oxide layer is smooth and dense, providing a barrier for further diffusion of oxygen. But chlorine has the ability to penetrate the protective oxide layer, through pores and cracks to the scale metal interface, where it reacts with the dip tube and creates severe corrosion.
Figure 5: Hydrogen chloride in the flue gas
The FLSmidth R&D centre has carried out intensive research work and is in the process of developing (refer to figure 6) a new corrosion resistant alloy, which offers greater benefits to the customer, in terms of product life and performance.
Figure 6: New corrosion resistant alloy
(This article has been authored by Biju Karakkunnummal, Metallurgist, FLSmidth Pvt. Ltd).
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FORNNAX Technology lays foundation for a 23-acre facility in Gujarat
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FORNNAX Technology, a leading manufacturer of recycling equipment in India, has marked a major milestone with the Groundbreaking (Bhoomi Pujan) ceremony for its expansive 23-acre manufacturing facility in Gujarat. Specialising in high-capacity shredders and granulators, FORNNAX is strategically positioning itself as a global leader in the recycling industry. The new plant aims to produce 250 machinery units annually by 2030, making it one of the largest manufacturing facilities in the world.
The foundation stone for this ambitious project was laid by Jignesh Kundaria, CEO and Director, alongside Kaushik Kundaria, Director. The ceremony was attended by key leadership members and company staff, signifying a new chapter for FORNNAX as it meets the growing demand for reliable recycling solutions. Speaking on the occasion, Jignesh Kundaria stated, “This marks a historic moment for the recycling sector. Our high-quality equipment will address various waste categories, including tyre, municipal solid waste (msw), cables, e-waste, aluminium, and ferrous metals. this facility will strengthen our global presence while contributing to India’s Net Zero emissions goal by 2070.”
FORNNAX is actively expanding its footprint in critical markets such as Australia, Europe and the GCC, forging stronger sales and service partnerships. The facility will house an advanced Production Department to ensure seamless manufacturing.
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Decarbonisation is a focus for our R&D effort
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2 months agoon
February 12, 2025By
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Dyanesh Wanjale, Managing Director, Gebr. Pfeiffer discusses the need to innovate grinding technologies to make the manufacturing process more efficient and less fuel consuming.
Gebr. Pfeiffer stands at the forefront of grinding technology, delivering energy-efficient and customised solutions for cement manufacturers worldwide. From pioneering vertical roller mills to integrating AI-driven optimisation, the company is committed to enhancing efficiency and sustainability. In this interview, we explore how their cutting-edge technology is shaping the future of cement production.
Can you tell us about the grinding technology your company offers and its role in the cement industry?
We are pioneers in grinding technology, with our company being based in Germany and having a rich history of over 160 years, a milestone we will celebrate in 2024. We are widely recognised as one of the most efficient grinding technology suppliers globally. Our MBR mills are designed with energy efficiency at their core, and for the past five years, we have been focused on continuous improvements in power consumption and reducing the CO2 footprint. Innovation is an ongoing process for us, as we strive to enhance efficiency while supporting the cement industry’s sustainability goals. Our technology plays a critical role in helping manufacturers reduce their environmental impact while improving productivity.
The use of alternative fuels and raw materials (AFR) is an ever-evolving area in cement production. How does your technology adapt to these changes?
Our vertical roller mills are specifically designed to adapt to the use of alternative fuels and raw materials. These mills are energy-efficient, which is a key advantage when working with AFR since alternative fuels often generate less energy. By consuming less power, our technology helps bridge this gap effectively. Our solutions ensure that the use of AFR does not compromise the operational efficiency or productivity of cement plants. This adaptability positions our technology as a vital asset in the industry’s journey toward sustainability.
What are some of the challenges your company faces, both in the Indian and global cement industries?
One of the major challenges we face is the demand for expedited deliveries. While customers often take time to decide on placing orders, once the decision is made, they expect quick deliveries. However, our industry deals with heavy and highly customised machinery that cannot be produced off the shelf. Each piece of equipment is made-to-order based on the client’s unique requirements, which inherently requires time for manufacturing.
Another significant challenge comes from competition with Chinese suppliers. While the Indian cement industry traditionally favoured our technology over Chinese alternatives, a few customers have started exploring Chinese vertical roller mills. This is concerning because our German technology offers unmatched quality and longevity. For example, our mills are designed to last over 30 years, providing a long-term solution for customers. In contrast, Chinese equipment often does not offer the same durability or reliability. Despite the cost pressures, we firmly believe that our technology provides superior value in the long run.
You mentioned that your machinery is made-to-order. Can you elaborate on how you customise equipment to meet the specific requirements of different cement plants?
Absolutely. Every piece of machinery we produce is tailored to the specific needs of the customer. While we have standard mill sizes to cater to different capacity requirements, the components and configurations are customised based on the client’s operational parameters and budget. This process ensures that our solutions deliver optimal performance and cost efficiency. Since these are heavy and expensive items, maintaining an inventory of pre-made equipment is neither practical nor economical. By adopting a made-to-order approach, we ensure that our customers receive machinery that precisely meets their needs.
The cement industry is focusing not only on increasing production but also on decarbonising operations. How does your company contribute to this dual objective, and how do you see this evolving in the future?
Decarbonisation is a key focus for our research and development efforts. We are continuously working on innovative solutions to reduce CO2 emissions and improve overall sustainability. For example, we have significantly reduced water consumption in our processes, which was previously used extensively for stabilisation. Additionally, we are leveraging artificial intelligence to optimise mill operations. AI enables us to monitor the process in real-time, analyse feedback, and make adjustments to achieve optimal results within the given parameters.
Our commitment to innovation ensures that we are not only helping the industry decarbonise but also making operations more efficient. As the cement industry moves toward stricter sustainability goals, we are confident that our technology will play a pivotal role in achieving them.
Can you provide more details about the use of digitalisation and artificial intelligence in your processes? How does this improve your operations and benefit your customers?
Digitalisation and AI are integral to our operations, enabling us to offer advanced monitoring and optimisation solutions. We have developed three distinct models that allow customers to monitor mill performance through their computer systems. Additionally, our technology enables real-time feedback from our German headquarters to the customer. This feedback highlights any inefficiencies, such as when a parameter is outside the optimal range,
and provides actionable recommendations to address them.
By continuously monitoring every parameter in real time, our AI-driven systems ensure that mills operate at peak efficiency. This not only enhances production but also minimises downtime. I am proud to say that our mills have the lowest shutdown rates compared to other manufacturers. This reliability, combined with the insights provided by our digital solutions, ensures that customers achieve consistent and efficient operations. It’s a game-changer for reducing costs and enhancing overall productivity.
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Technology is the cornerstone of clinker cooling
Published
4 months agoon
December 24, 2024By
Roshna
Madhusudan Rasiraju, Country Head, IKN India, talks about enhancing cement plant efficiency with energy-saving, reliable, and customised solutions while supporting sustainability through innovations like oxy-fuel plants and AFR adaptability.
Could you explain what IKN Engineering is, what the company specialises in, and share insights about your clinker cooling solutions?
IKN is a Germany-based company that specialises in providing advanced clinker cooling solutions to the cement industry. Our expertise lies in developing and supplying innovative cooling systems that focus on energy efficiency, durability and cost-effectiveness.
The clinker cooling process is a critical stage in cement production, as it significantly influences the energy efficiency of the entire plant. Our coolers are designed with cutting-edge technology to recuperate a substantial amount of heat from the clinker. This recovered heat is redirected back into the cement production process, enabling our customers to reduce their fuel consumption significantly. Moreover, IKN coolers are engineered for reliability. They are built to operate with minimal maintenance, which helps to lower operational costs and reduce downtime. By focusing on high performance and long-term reliability, we ensure that our solutions are both economically and environmentally beneficial.
How does IKN contribute to improving the efficiency of cement plant operations and supporting sustainability goals?
IKN plays a pivotal role in enhancing the operational efficiency of cement plants while aligning with global sustainability objectives. Historically, clinker coolers required frequent maintenance, with intervals as short as five to six months. This led to regular shutdowns, which disrupted operations and increased costs. With IKN’s advanced cooling solutions, cement plants can now operate their coolers for extended periods without significant maintenance. Our coolers are not only more reliable but also consume less power, which directly reduces energy costs. Additionally, the high heat recuperation efficiency of our systems ensures that less fuel is required for the cement-making process, contributing to a lower carbon footprint.
Sustainability is embedded in our solutions. By reducing energy consumption, optimising processes, and minimising maintenance, we help our customers achieve their operational goals while supporting their commitment to environmental stewardship.
What role does technology play in the clinker cooling process, and how does IKN leverage it to provide advanced solutions?
Technology is the cornerstone of clinker cooling and a driving force behind our innovative solutions at IKN. The cement industry’s needs are constantly evolving, and to stay ahead, we ensure our technologies remain dynamic and adaptable. We adopt a customer-centric approach, continuously collecting feedback from our clients to improve our systems. Every clinker cooler we supply is tailored to meet the specific requirements of the plant it serves. For instance, the physical layout, production capacity, and operational challenges of each facility are unique, and we ensure our solutions address these specific needs.
Moreover, our ongoing research and development efforts focus on enhancing reliability, improving heat recovery, and lowering energy consumption. By integrating the latest technological advancements, we make sure our coolers set new benchmarks in performance and sustainability.
Do you offer customised solutions for each cement plant, and how does the increasing use of alternative fuels (AFR) impact your clinker cooling solutions?
Absolutely, customisation is at the core of what we do at IKN. In the case of retrofits, every cooler is custom-designed to fit the specific layout and operational needs of the existing cement plant. For new installations, we collaborate closely with our clients to design coolers that are precisely sized and configured to meet their requirements.
Regarding alternative fuels (AFR), their increasing use in cement plants presents unique challenges. AFR often results in the production of finer clinker, which can be more difficult to handle during the cooling process. To address this, we optimise the operating parameters of our coolers, such as airflow density and cooler speed, to ensure they perform effectively with the type of clinker being produced. This adaptability ensures that our coolers remain efficient and reliable, even in plants using diverse and non-traditional fuels.
What challenges do you face in providing clinker cooling solutions, both from your operations and from the cement industry’s perspective?
Challenges are inevitable in any advanced technological field, and clinker cooling is no exception. One of the primary challenges we face is adapting to the changing demands of our customers. For example, frequent shifts in fuel types or the introduction of AFR can disrupt the cooling process. These changes often result in variations in clinker properties, requiring us to make adjustments to maintain optimal performance. Additionally, the grid surfaces in coolers may face increased wear and tear due to these changes. At IKN, we address such challenges by reinforcing the grid surfaces and fine-tuning our systems to handle these dynamic conditions.
From an industry perspective, there is an increasing emphasis on efficiency, sustainability, and cost reduction. Meeting these expectations while maintaining high performance is challenging, but it is a challenge we embrace through innovation, research, and collaboration with our clients.
What are your views on the net zero mission, and how is IKN contributing toward this goal?
The net zero mission is a vital initiative for energy-intensive industries such as cement, steel, and power. It requires a collective effort across the supply chain to achieve meaningful progress.
At IKN, we are committed to supporting this global goal. One of our key contributions is the development of oxy-fuel plants, which are designed to significantly reduce carbon emissions during production. We are also exploring innovative cooling methods, such as the use of nitrogen or other media, to further enhance sustainability. Currently, we have two oxy-fuel projects underway in Germany. These plants not only demonstrate our commitment to the net zero mission but also serve as examples of how advanced technology can drive sustainability in the cement industry. By focusing on durability, efficiency, and innovation, we help our clients reduce their environmental footprint while maintaining high operational standards.
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