Effective sustainability practices in a Cimprogetti’s lime regenerative kiln process
In recent decades the lime Industry, like many other industrial sectors, has been exploring alternative solutions to high energy-consuming production processes. This shift is driven by various factors, including the desire to reduce environmental impact, enhance sustainability, and mitigate the industry’s dependence on traditional fossil fuels.
Cimprogetti is recently implementing energy-saving practices after selecting an innovative process air blower technology for the combustion process, and the cooling of quicklime and lances, with the aim to move on a long-term sustainable future.
This article proposes an analysis of the effective sustainability of said innovative Turbo Blower technology, carried out through simulation and with the contribution of the Aerzen company, with which we signed a robust commercial partnership agreement. Cimprogetti and Aerzen have collaborated in the last years on developing an innovative machine tailored specifically for operating in a lime plant facility.
Designing suitable curves for the pressure and operation of a modern regenerative kiln involves careful consideration of various factors, including the kiln’s capacity, efficiency requirements, fuel type, and operating conditions. The project aimed for ambitious targets including energy efficiency, noise reduction, vibration reduction and lower environmental impact.
The profitable collaboration involved mutual technical areas identifying complementary strengths, aligning goals to ensure that the machine’s specifications aligned with the requirements of a modern double shaft kiln process. This likely included considerations such as the varying operating and loading conditions of the plant.
Given the challenging operating conditions, such as dust and high temperatures, the project required the adoption of specific technical solutions that would address these issues both for the machines themselves and for the blower room. These solutions likely involved robust design considerations, specialized materials, and additional filtration or cooling systems to ensure optimal performance and longevity in such environments.
Cimprogetti and Aerzen will the drive lime industry into a future with a lower environment impact by focusing on energy efficiency, operational flexibility, and maximizing efficiency; the innovative solutions developed through this collaboration could contribute significantly to reducing the environmental footprint of lime production processes.
Digitalization era
Although electrical energy is representing a “low-cost” factor in regenerative kiln technology, ranging around 10% of the total production cost, it’ll be a driving factor to contribute to sustainable development and address the growing concerns of climate change and resource depletion.
Industry 4.0 and the digitalization era are teaching that the kiln is no longer just an instrumented carpentry managed by an automation software but is the full integration of equipment, automation, software, able to produce all the necessary services and information to achieve the highest operational efficiency.
The operating graphs of the Turbo machines as well as the operating characteristic performance curves have been specifically designed to operate on double shaft regenerative kilns. Cimprogetti’s control system BOT Platform™ has been updated to integrate all the Turbo compressors data and to guarantee operational flexibility and the maximum level of efficiency. These features provide a comprehensive set of monitoring and control capabilities, ensuring an efficient kiln operation for both local and remote management.
High efficiency
Turbo Blowers are equipped with high-efficiency and energy-saving permanent magnet motors and with latest generation inverters (> 60 HP in double IGBT multilevel execution). The air bearings and the direct coupling of the impeller to the motor shaft avoid any gearboxes, transmissions, lubrication circuits and frictions, resulting in a consumption reduction of an average of 15% compared to standard lobes technologies.
The inverter ensures a wide range of flow regu-lation at different kiln pressure and contributes to “rephasing” the device, allowing a lower load on the customer‘s system power factor corrector and even its elimination. The use of the latest generation inverters, especially those with double IGBT (Insulated Gate Bipolar Transistor) multilevel execution for models exceeding 60 HP, signifies advanced technology adoption. This overall efficiency gain is crucial for lowering operational costs and aligning with sustainability goals.
A simulation conducted on a 400-t-per-day Parallel Flow Regenerative Kiln (PFRK) natural gas-fired emphasizes that the Turbo Blowers consume approximately 100 kW less electricity compared to the Lobe Blowers. This translates to potential electricity annual savings of around € 150000 (computed based on EU pricing).
Minimized footprint
Turbo Blowers exhibit a footprint on the plant layout that is roughly one-third smaller than conventional volumetric technologies or fan blower, despite being already equipped with inverters and acoustic hood. Furthermore, the delivery flange is placed in the upper part of the acoustic, thus avoiding the encumbrance of hot and noisy pipes on the ground.
Our calculations for a Parallel Flow Regenerative Kiln (PFRK) of 400 tpd nominal capacity natural gas-fired determine that the total weight of a turbo blower room and its primary components, including the pumping unit and the inverter, is approximately 40% less when compared to conventional technology. This reduction leads to a corresponding 30-40% decrease in the amount of concrete and steel reinforcement needed for the civil foundation.
Reducing the use of concrete and steel is indeed a crucial aspect of mitigating indirect carbon dioxide (CO2) emissions, as both materials are associated with significant carbon footprints and reducing the investment cost in industrial buildings. The use of simple manual lifters makes it possible to manage any movement without using cranes, forklifts and/or overhead traveling cranes.
Reduced sound pressure level
The emphasis on maintaining a sound pressure level below 70 dB(A) in Turbo Blowers is crucial for ensuring a safe and comfortable working environment. Operators, equipped with suitable Personal Protective Equipment (PPE) and ortho protectors, can perform both ordinary and extra-ordinary maintenance tasks on a single machine, even when the other blowers are in operation, contributing to reducing any potential disruptions.
Maintenance activities that do not require plant shutdowns contribute to high quality materials and do not pose a risk of thermal shock on the lime kiln. In general, compared to standard technologies, Turbo Blowers ensure a lower acoustic impact for the benefit of operators and work environment, ensuring operational flexibility, continuous functionality and minimizing downtime.
Reliability and resistance
Turbo Blowers are equipped with a stainless-steel impeller keyed directly to the motor shaft and are 100% oil-free ensuring reliability and resistance to chemical aggression. The use of the inverter ensures controlled cues in the electrical substation for the benefit of the customer‘s electrical system. Turbo Blowers are designed to operate 24/365 days and are characterized by the almost absence of vibration. No parts are subject to constant friction and maintenance is limited to filters replacement.
Conclusion
The ability to transversely address all environmental, social, and good governance aspects, as well as the ability to react to disruptive events, is a fundamental milestone for the long-term survival of industrial facilities. Cimprogetti supports its customers pursuing innovation and continuous research to improve its technologies and select the most promising solutions available on the market and key players in the lime production industry have already expressed their trust in Cimprogetti‘s advanced technology and its adept approach to inventive solutions.
Replacing traditional Lobe Blowers with Turbo machines for the kiln process air showcases a very efficient and innovative solution for companies that focus on energy efficiency, OPEX reduction, advanced control capabilities, and, last but not least, a safe and comfortable working environment. The adoption of these cutting-edge solutions is in harmony with worldwide endeavours to tackle environmental issues and encourage sustainable practices in various sectors.
From simple queries, Cimprogetti engineers are able to develop predictive analytics tools for plant performance analysis and asset management that aim at the improvement of economic benefits and control performances of the lime plant.
Feel free to reach out to our Technical Department for a plant energy assessment and estimating the operational cost saving with the use of the Turbo Blowers.
