Environment
An effective pollution control device
Published
8 years agoon
By
admin
Over a period of time, baghouse has overtaken ESP in pollution control. In many cement plants, ESPs are getting replaced with a baghouse. Let us see the advantages of baghouse.
A baghouse, which uses ‘filter bags’, is an air pollution control device that removes particulates out of air or gas released from chemical processes or combustion for electricity generation. Cement and power plants, steel mills, pharmaceutical producers, food manufacturers, chemical producers and other industrial companies often use baghouses to control emission of air pollutants. Baghouses came into widespread use in the late 1970s after the invention of high-temperature fabrics to be used as filter media capable of withstanding temperatures over 3000 C.
Functioning of baghouses typically has a particulate collection efficiency of 99 per cent or better, irrespective of particle size. However in case of electrostatic precipitators, the performance may vary significantly depending on process and electrical conditions.Operation
Most baghouses use long, cylindrical bags or tubes made of woven or felted fabric as a filter medium placed in a very big chamber. (For applications where there is relatively low dust loading and gas temperatures are 120?C or less, pleated, nonwoven cartridges are sometimes used as filtering media instead of bags. Typically dust-laden gas or air enters the baghouse through hoppers large funnel-shaped containers used for storing and dispensing particulate and is directed into the baghouse compartment. The gas is drawn through the bags, either on the inside or the outside depending on cleaning method, and a layer of dust accumulates on the filter media surface until air can no longer move through it. When sufficient pressure drop (delta P) occurs, the cleaning process begins. Cleaning can take place while the baghouse is online (filtering) or is offline (in isolation). When the compartment is clean, normal filtering resumes.
Baghouses are very efficient particulate collectors because of the dust cake formed on the surface of the bags. A combination of these mechanisms results in formation of the dust cake on the filter, which eventually increases the resistance to gas flow. The filter must be cleaned periodically.Baghouse types – Cleaning methods: Baghouses are classified by the cleaning method used. The three most common types of baghouses are mechanical shakers, reverse gas, and pulse jet.Performance of a baghouse
Baghouse performance is contingent upon inlet and outlet gas temperature, pressure drop, opacity, and gas velocity. The chemical composition, moisture, acid dew point, and particle loading and size distribution of the gas stream are essential factors as well.Gas temperature: Fabrics are designed to operate within a certain range of temperature. Fluctuation outside of these limits even for a small period of time,can weaken, damage the bags.Pressure drop: Baghouses operate most effectively within a certain pressure drop range. This spectrum is based on a specific gas volumetric flow rate.Opacity: Opacity measures the quantity of light scattering that occurs as a result of the particles in a gas stream. Opacity is not an exact measurement of the concentration of particles; however, it is a good indicator of the amount of dust leaving the baghouse.Gas volumetric flow rate: Baghouses are created to accommodate a range of gas flows. An increase in gas flow rates causes an increase in operating pressure drop and air-to-cloth ratio. These increases require the baghouse to work more strenuously, resulting in more frequent cleanings and high particle velocity, two factors that shorten bag life.Fabric and filter bag
Fabric filter bags are either oval or round tubes, typically 15-30 feet and 5 to 12 inches in diameter, made of woven or felted material. Depending on chemical and/or moisture content of the gas stream, its temperature, and other conditions, bags may be constructed out of cotton, nylon, polyester, fibreglass or other materials.
Nonwoven materials are either felted or membrane. Nonwoven materials are attached to a woven backing (scrim). Felted filters contain randomly placed fibres supported by a woven backing material (scrim). In a membrane filter, a thin, porous membrane is bound to the scrim. High energy cleaning techniques such as pulse jet require felted fabrics.
Woven filters have a definite repeated pattern. Low energy cleaning methods such as shaking or reverse air allow for woven filters. Various weaving patterns such as plain weave, twill weave, or sateen weave, increase or decrease the amount of space between individual fibres. The size of the space affects the strength and permeability of the fabric. A tighter weave corresponds with low permeability and, therefore, more efficient capture of fine particles.
Reverse air bags have anti-collapse rings sewn into them to prevent pancaking when cleaning energy is applied. Pulse jet filter bags are supported by a metal cage, which keeps the fabric taut. To extend the life of filter bags, a thin layer of PTFE (teflon) membrane may be adhered to the filtering side of the fabric, keeping dust particles from becoming embedded in the filter media fibres. Some baghouses use pleated cartridge filters, similar to what is found in home air filtration systems.Reverse Air Bag House (RABH): The typical RABH is modular in construction, with four or more independent modules – the modules being set in pairs, when the gas flows are on the higher side. The sealed air gap between the modules, adds to the insulation to increase operating economy. The extra space created by the hoppers provides a large passageway between rows down the middle of the system. This passageway is divided into three sections horizontally to make the inlet plenum, outlet plenum, and the reverse-air plenum.Reverse Gas Flow: Each module is periodically and automatically shut-down for a brief reverse-air cleaning as per the system logic. Clean hot gas is drawn from the outlet plenum by the reverse-air fan into the reverse-air plenum during cleaning. During the process, the outlet damper is closed and the reverse-air damper is opened, letting in the reverse air in the opposite direction from the normal dusty gas flows. This action slowly collapses the bags breaking up the dust cake on the inner bag surfaces allowing the dust to get discharged to the hopper.
Several Industrial units – cement, steel and power plants – had installed electrostatic precipitators (ESPs) for emission control. These ESPs were designed for earlier emission norms of about 150 mg/Nm3 now the revised norms for Pollution Control Boards are at stringent level of about 30 mg/Nm3. In addition industries also have to deal with changes in process inputs, inferior quality coal and increase in capacity which causes higher pollution. Installing a new ESP is costly and in most of the cases unfeasible due to limited space in the plant. Add to these the costs of long shutdowns and production loss. These old ESPs can be retrofitted to fabric filter by combining the functions of an ESP and a bag filter. Dust emission is reduced to about 10 mg/Nm3. For industries like cement, the product achieves futuristic environment norms and product recovery.Challenges
Emissions control is a hot topic in the cement industry. Cement plants are generally driven by production numbers, but if they fail to comply with the new NESHAP (National Emission Standards for Hazardous Air Pollutants) regulations, production could be stopped immediately, introducing a slew of cost factors that affect plants’ bottom line.
What’s more challenging for cement plants is how compliance is calculated, with the MACT (Maximum Achievable Control Technology) approach, which sets compliance limits in line with the top 12 per cent of plants. Plant compliance is calculated not at a given moment, but on a 30-day rolling average.
Prior to NESHAP, plants had to prove their compliance based on annual tests. The MACT approach to setting the new limit at the average of the best 12 per cent is a significant change. What makes the change even more challenging are plants having to now prove their compliance on a continuous 30-day rolling average.
As industry and baghouse needs have evolved, Gore has introduced new developments in filtration technology that deliver industry-leading performance and reliability. To meet the requirements of the industry are brought in by the manufacturers e.g. products include our GORE Low Emission Filter Bags, which are seam-taped to block emissions, ensuring cement plants meet NESHAP and other regulations.
DeNOx Catalytic Filter Bags are designed to destroy NOx and NH3 at levels similar to an SRC tower, but at a much lower investment cost. GORE Low Drag Filter Bags are proven to increase throughput by promoting greater airflow. The same manufacturer has Mercury Control System (GMCS) is a unique fixed sorbent system for capturing elemental and oxidised gas phase mercury from flue gas streams and reduces SO2 concentrations. One would normally expect not to have any process changes in the running plant.Three factors
Baghouse operators purchase filter bags primarily for particulate collection. This is a primary filtration factor. As the particulate is collected, the resistance to flow, differential pressure, increases, causing higher fan energy costs. This is a secondary filtration factor. When the filters have holes so they are no longer as efficient at particulate capture as they need to be or when the differential pressure of the filter bags is too high, the filter bag life is over. Although life is usually one of the major factors considered during a filter selection, it is defined by the primary and secondary factors. Gore provides the optimal balance of extremely high filtration efficiency very low resistance to flow and extremely long filter life. Typically, filter bags will provide five-year effective filter bag life in a pulse jet cement kiln baghouse.
Gore recently introduced GORE Low Drag Filter Bags – a step change in industrial dry filtration. An entirely new class of membranes developed by Gore acts as a true surface filter in fume and fine powder applications. The low drag technology, "Drag" is defined as the resistance of a filtration material to airflow. The new materials are inherently less resistant to airflow and are therefore more efficient with respect to the amount of energy required to drive air through them during filtration. The key is improved cleanability, without sacrificing durability or particle capture efficiency.The dust collection on fabric filters through the following four mechanisms:
- Inertial collection: Dust particles strike the fibres placed perpendicular to the gas-flow direction instead of changing direction with the gas stream.
- Interception: Particles that do not cross the fluid streamlines come in contact with fibres because of the fibre size.
- Brownian movement: Submicrometre particles are diffused, increasing the probability of contact between the particles and collecting surfaces.
- Electrostatic forces: The presence of an electrostatic charge on the particles and the filter can increase dust capture.
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Concrete
We engineer smarter systems to reduce waste
Published
2 months agoon
December 12, 2025By
admin
Naveen Kumar Sharma, AVP – Sales and Marketing, Toshniwal Industries, talks about redefining instrumentation with customised, digitally enabled solutions engineered for harsh plant environments.
For over six decades, Toshniwal Industries has played a pioneering role in advancing process instrumentation for Indian manufacturing. In this exclusive conversation with Kanika Mathur, Naveen Kumar Sharma, AVP – Sales & Marketing, explains how the company designs kiln and grinding plant solutions tailored to the unique demands of the cement industry. As plants transition to higher AFR use and smarter automation, Toshniwal’s technologies offer greater reliability, accuracy and predictive insight.
Tell us how are your process instruments and condition monitoring system customised for cement kilns and grinding plant operations?
Toshniwal is a company with a legacy of over 65 years, and our experience has taught us that cement kilns and grinding units are fundamentally different in their operational demands. As an Indian company, we understand the unique requirements of Indian cement manufacturers. We work closely with our customers, engage deeply with their technical teams, and study operational challenges in real-time.
Based on these insights, we customise our solutions for both kiln and grinding applications. This tailoring is not just at a product level, but at a solution level—engineering design, instrumentation logic, and process optimisation. Our primary objective, for both the industry and our customers, is to reduce yield loss. Every customisation we implement is driven by this goal. We engineer smarter systems to reduce waste, improve consistency and increase plant reliability.
Ultimately, our solutions are built on an understanding that cement manufacturers require robust, practical and maintainable instruments. We design with this mindset so plants can operate more efficiently, with better control and higher profitability.
With the rising use of AFR, how do your solutions support thermal zone reliability and process time?
Our solutions are built around four core parameters: energy efficiency, yield loss reduction, product quality and environmental responsibility. These pillars drive our engineering decisions and define how our technologies support cement plants, especially as they adopt alternative fuels and raw materials (AFR).
We strongly believe in energy conservation. Every product we offer—whether for thermal monitoring, kiln control or flame optimisation—is engineered to improve energy performance. Reducing yield loss is another principle deeply embedded in our solutions, because production interruptions and material losses directly affect plant profitability and clinker quality.
We are also highly conscious of the end-product quality delivered by our customers to their markets. Consistency in burning, heat transfer, and thermal profiling directly influences clinker characteristics, and our instruments help maintain this stability.
Lastly, and most importantly, we care about the environment. We want to leave a greener world for the next generation. This mindset aligns with India’s digitalisation movement, advocated by our Prime Minister. Digital technologies are crucial for optimising AFR use, process stability, emissions and kiln efficiency. We are proud to contribute to this transition.
By optimising flame patterns, energy use, and pollution, our solutions deliver direct and indirect savings. Plants benefit from lower operational losses, reduced maintenance, and improved reliability, especially in pyroprocessing zones.
Tell us how do you address harsh environment challenges in cement plants, say dust, temperature, etc. with your sensor and monitoring?
This is a very important question because cement plants, steel plants, and power plants operate in extremely harsh environments. There are two major categories of specifications that we must respect while designing solutions: technical specifications and environmental specifications. Technical specifications relate to performance accuracy, measurement integrity, responsiveness and process safety. Environmental specifications, on the other hand, relate to high temperatures, heavy dust, humidity, vibrations and corrosive atmospheres. Our solutions are engineered to withstand both. We customise sensors, housings, mounting mechanisms and protective systems so that our instruments operate at 100 per cent functionality in harsh conditions. We ensure that the plant experiences minimal downtime from our systems. That is our engineering philosophy—solutions must work reliably in real-world environments, not just in ideal laboratory conditions.
What retrofit pathways do you offer for older cement lines to upgrade measurement and monitoring systems and how is the Indian market responding?
Every solution we provide is scalable and digitally adaptable. Technology evolves rapidly, and our offerings evolve with it. When we upgrade instruments or monitoring systems, we design them to integrate with existing plant infrastructure, so customers do not have to rebuild everything from scratch. Once our solution is installed, software upgrades or performance improvements can often be deployed without major cost. This ensures that customers continue to benefit from ongoing technological advancements. The Indian market has responded positively to this approach. Plant operators appreciate solutions that are future-ready and dynamic rather than static. Scalability helps them maintain competitiveness, extend asset life, and move toward smart manufacturing with confidence.
So how is your organisation leveraging digital technologies in your instrumentation portfolio for cement plants?
Digitalisation is at the core of every product we manufacture. We stand firmly behind the digital movement, not only because it represents efficiency, but because it is the direction in which the Indian industrial ecosystem is evolving. We deploy machine-vision technologies, advanced inline monitoring systems, and solutions capable of visualising the
inside of the furnace. These systems help reduce downtime, enable predictive asset management and provide actionable analytics to customers. All our technologies communicate seamlessly with Level 1, Level 2, and Level 3 automation. This allows integration across SCADA, DCS, ERP, and cloud ecosystems. Digitalisation for us is not an add-on—it is foundational to how our instrumentation is built.
What are your key innovation priorities to help Indian cement plant producers hit harder, higher substitution rates, lower emissions and smarter processing?
Sustainability is a national priority, and we are committed to supporting it. Our current portfolio already helps improve efficiency, reduce emissions, and support alternative fuel integration. But our innovation roadmap goes further. We are now developing specialised productivity-oriented software modules that will provide proactive alerts—not just alarms triggered after a fault has occurred. These modules will leverage artificial intelligence and machine learning to detect patterns early. The intention is to help plant teams take corrective actions ahead of time, reducing yield loss and environmental impact. Instead of informing the plant that a disruption has happened, the system will indicate that a disruption will happen, giving operators time to prevent it. We believe that within the next 12 to 18 months, we will launch these predictive solutions in combination with our instrumentation. When implemented, they will significantly improve decision-making, process stability and environmental performance across the Indian cement sector.
– Kanika Mathur
Concrete
India donates 225t of cement for Myanmar earthquake relief
Published
8 months agoon
June 17, 2025By
admin
On 23 May 2025, the Indian Navy ship UMS Myitkyina arrived at Thilawa (MITT) port carrying 225 tonnes of cement provided by the Indian government to aid post-earthquake rebuilding efforts in Myanmar. As reported by the Global Light of Myanmar, a formal handover of 4500 50kg cement bags took place that afternoon. The Yangon Region authorities managed the loading of the cement onto trucks for distribution to the earthquake-affected zones.
Concrete
Reclamation of Used Oil for a Greener Future
Published
8 months agoon
June 16, 2025By
admin
In this insightful article, KB Mathur, Founder and Director, Global Technical Services, explores how reclaiming used lubricants through advanced filtration and on-site testing can drive cost savings, enhance productivity, and support a greener industrial future. Read on to discover how oil regeneration is revolutionising sustainability in cement and core industries.
The core principle of the circular economy is to redefine the life cycle of materials and products. Unlike traditional linear models where waste from industrial production is dumped/discarded into the environment causing immense harm to the environment;the circular model seeks to keep materials literally in continuous circulation. This is achievedthrough processes cycle of reduction, regeneration, validating (testing) and reuse. Product once
validated as fit, this model ensures that products and materials are reintroduced into the production system, minimising waste. The result? Cleaner and greener manufacturing that fosters a more sustainable planet for future generations.
The current landscape of lubricants
Modern lubricants, typically derived from refined hydrocarbons, made from highly refined petroleum base stocks from crude oil. These play a critical role in maintaining the performance of machinery by reducing friction, enabling smooth operation, preventing damage and wear. However, most of these lubricants; derived from finite petroleum resources pose an environmental challenge once used and disposed of. As industries become increasingly conscious of their environmental impact, the paramount importance or focus is shifting towards reducing the carbon footprint and maximising the lifespan of lubricants; not just for environmental reasons but also to optimise operational costs.
During operations, lubricants often lose their efficacy and performance due to contamination and depletion of additives. When these oils reach their rejection limits (as they will now offer poor or bad lubrication) determined through laboratory testing, they are typically discarded contributing to environmental contamination and pollution.
But here lies an opportunity: Used lubricants can be regenerated and recharged, restoring them to their original performance level. This not only mitigates environmental pollution but also supports a circular economy by reducing waste and conserving resources.
Circular economy in lubricants
In the world of industrial machinery, lubricating oils while essential; are often misunderstood in terms of their life cycle. When oils are used in machinery, they don’t simply ‘DIE’. Instead, they become contaminated with moisture (water) and solid contaminants like dust, dirt, and wear debris. These contaminants degrade the oil’s effectiveness but do not render it completely unusable. Used lubricants can be regenerated via advanced filtration processes/systems and recharged with the use of performance enhancing additives hence restoring them. These oils are brought back to ‘As-New’ levels. This new fresher lubricating oil is formulated to carry out its specific job providing heightened lubrication and reliable performance of the assets with a view of improved machine condition. Hence, contributing to not just cost savings but leading to magnified productivity, and diminished environmental stress.
Save oil, save environment
At Global Technical Services (GTS), we specialise in the regeneration of hydraulic oils and gear oils used in plant operations. While we don’t recommend the regeneration of engine oils due to the complexity of contaminants and additives, our process ensures the continued utility of oils in other applications, offering both cost-saving and environmental benefits.
Regeneration process
Our regeneration plant employs state-of-the-art advanced contamination removal systems including fine and depth filters designed to remove dirt, wear particles, sludge, varnish, and water. Once contaminants are removed, the oil undergoes comprehensive testing to assess its physico-chemical properties and contamination levels. The test results indicate the status of the regenerated oil as compared to the fresh oil.
Depending upon the status the oil is further supplemented with high performance additives to bring it back to the desired specifications, under the guidance of an experienced lubrication technologist.
Contamination Removal ? Testing ? Additive Addition
(to be determined after testing in oil test laboratory)
The steps involved in this process are as follows:
1. Contamination removal: Using advanced filtration techniques to remove contaminants.
2. Testing: Assessing the oil’s properties to determine if it meets the required performance standards.
3. Additive addition: Based on testing results, performance-enhancing additives are added to restore the oil’s original characteristics.
On-site oil testing laboratories
The used oil from the machine passes through 5th generation fine filtration to be reclaimed as ‘New Oil’ and fit to use as per stringent industry standards.
To effectively implement circular economy principles in oil reclamation from used oil, establishing an on-site oil testing laboratory is crucial at any large plants or sites. Scientific testing methods ensure that regenerated oil meets the specifications required for optimal machine performance, making it suitable for reuse as ‘New Oil’ (within specified tolerances). Hence, it can be reused safely by reintroducing it in the machines.
The key parameters to be tested for regenerated hydraulic, gear and transmission oils (except Engine oils) include both physical and chemical characteristics of the lubricant:
- Kinematic Viscosity
- Flash Point
- Total Acid Number
- Moisture / Water Content
- Oil Cleanliness
- Elemental Analysis (Particulates, Additives and Contaminants)
- Insoluble
The presence of an on-site laboratory is essential for making quick decisions; ensuring that test reports are available within 36 to 48 hours and this prevents potential mechanical issues/ failures from arising due to poor lubrication. This symbiotic and cyclic process helps not only reduce waste and conserve oil, but also contributes in achieving cost savings and playing a big role in green economy.
Conclusion
The future of industrial operations depends on sustainability, and reclaiming used lubricating oils plays a critical role in this transformation. Through 5th Generation Filtration processes, lubricants can be regenerated and restored to their original levels, contributing to both environmental preservation and economic efficiency.
What would happen if we didn’t recycle our lubricants? Let’s review the quadruple impacts as mentioned below:
1. Oil Conservation and Environmental Impact: Used lubricating oils after usage are normally burnt or sold to a vendor which can be misused leading to pollution. Regenerating oils rather than discarding prevents unnecessary waste and reduces the environmental footprint of the industry. It helps save invaluable resources, aligning with the principles of sustainability and the circular economy. All lubricating oils (except engine oils) can be regenerated and brought to the level of ‘As New Oils’.
2. Cost Reduction Impact: By extending the life of lubricants, industries can significantly cut down on operating costs associated with frequent oil changes, leading to considerable savings over time. Lubricating oils are expensive and saving of lubricants by the process of regeneration will overall be a game changer and highly economical to the core industries.
3. Timely Decisions Impact: Having an oil testing laboratory at site is of prime importance for getting test reports within 36 to 48 hours enabling quick decisions in critical matters that may
lead to complete shutdown of the invaluable asset/equipment.
4. Green Economy Impact: Oil Regeneration is a fundamental part of the green economy. Supporting industries in their efforts to reduce waste, conserve resources, and minimise pollution is ‘The Need of Our Times’.
About the author:
KB Mathur, Founder & Director, Global Technical Services, is a seasoned mechanical engineer with 56 years of experience in India’s oil industry and industrial reliability. He pioneered ‘Total Lubrication Management’ and has been serving the mining and cement sectors since 1999.
Refractory demands in our kiln have changed
Digital supply chain visibility is critical
Redefining Efficiency with Digitalisation
Cement Additives for Improved Grinding Efficiency
Digital Pathways for Sustainable Manufacturing
Refractory demands in our kiln have changed
Digital supply chain visibility is critical
Redefining Efficiency with Digitalisation
Cement Additives for Improved Grinding Efficiency
Digital Pathways for Sustainable Manufacturing
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