There is huge scope for older plants to modernise and optimise processes
To what extent it helps optimise energy and operational efficiency?
Process optimization can bring down power consumed per unit of cement manufactured and it also can reduce consumption of other resources like water, cooling air, compressed air and manpower. Optimization will improve better use of fuel and power per ton of cement produced and will impact overall operational cost of the plant.
How process optimisation helps bring down negative impact on environment?
In wake of the latest dictum given to cement plants to reduce the emissions of SPM to less than 30 mg/Nm3 by CPCB, it is of great importance that the cement plants optimise their processes and bring down the emissions to as low as possible with the existing plant and equipment. If they are able to do that, they will save a lot of money by way of not having to replace the existing equipment with new ones or go for an altogether new technology. The process optimization or process modification can give a lot of benefit to them and help comply with the new guideline without capex and reduce continuous high power consumption due to changing ESP into a bag filter.
What are the value additions offered by your company?
We can study the process and suggest the changes needed in the existing equipment with minimum modifications to meet the present day challenge of curtailing the emissions to less than 30 mg/Nm3. We have technical knowhow and products which can lower the emissions to less than 30 mg/Nm3 with a very low cost capex in existing equipment. We can give suggestions and work with the process engineers together to develop strategies to optimise or modify the present process in a manner where the existing equipment can be used to achieve the required emission norms.
What is the scope of retrofit in the current scenario?
Retrofits have been taking place on continuous basis in cement plants over last two decades. Same kilns have been upgraded by addition of one or two stages in the pre-heater or addition of calciners to produce some places nearly double the capacity they were originally designed for. Similarly, coolers have been retrofitted with the upgrades to enhance their capacity and match the increased capacity of kiln. Mills have been added or modified.
Air pollution control equipment like ESP have been converted to pulse jet type of bag filter or a hybrid of ESP and bag filter combination to achieve the collection efficiency desired and also to comply with the emission norms. The conventional filter bags have been replaced with EPTFE membrane laminated filter bags to achieve longer life, lesser operating pressure drop and lower emissions in cement kiln, cement mill, raw mill and coal mill bag filters. They have also debottlenecked the process and increased the mill through put.
Better controllers and changing TR sets and better sectionalisation have also helped in improving the performance of the ESPs. Duct conditioning of air and use of dual fluid nozzles in place of spill back nozzles have helped several plants in improving the GCT performance and thereby kiln ESP performance.
Provide us a couple of case studies
We are working with Heidelberg Cement India and Kesoram Industries on kiln as well as cooler ESPs to see that these equipment are upgraded to meet the emission norms prescribed by CPCB within this year. In the past we have converted coal mill ESP to bag filter and several cement mill ESPs to pulse jet type bag filter successfully and brought down the emission levels to less than 25 mg/Nm3.