Cement, Energy and Environment

31 4.0 Environment: Definition, Concept & Measures Reduced Gaseous Emissions: Emissions are released from cement kilns, coming from the physical and chemical reactions of the raw materials and from the combustion of fuels. The main constituents of the exit gases from a cement kiln are nitrogen from the combustion air, CO2 from the Calciner and combustion, water from the combustion process and the raw materials, and excess oxygen. The exit gases also contains small quantities of dust, chlorides, fluorides, Sulphur dioxides, NOx , carbon monoxide, and still smaller quantities of organic compounds and heavy metals like mercury (Hg).At present norms exist for dust, TOC, HCl, HF, SOx, NOx Hg, Heavy Metals and Dioxin in India which are comparable or better as compared other developing countries. There is a system consisting of equipment to draw, condition and analyze the flue gas sample and provide permanent record of emissions and process parameters continuously at real time basis and is called “Continuous Emission Monitoring System (CEMS).Its of vital importance to install the CEMS system as the source can be controlled after measuring the emissions.However some of the cement manufactures in India have not installed the CEMS in their cement plants. It has to be of collaborative efforts of Cement manufactures, suppliers, consultants and Govt. to achieve the objective of emission control. KHD is trying to ensure that all the plants equipped with KHD technology get CEMS implemented to protect the environment. An example equipment from KHD for reducing the emissions at source is the Low NOx burner (Pyro- Jet® Burner). The most imperative features of the burner are the Low NOx emissions, low primary air & flame (stable & uniform) characteristics. The flame of the PYRO-JET® burner has both an internal recirculation zone and a long external one which results in considerable NOx reduction. Pyroclon®-R LowNOx AF is the special design calciner which attains retention time which is desired for complete burnout of the fuel.Another prominent solution from KHD for reducing the NOX emissions is the PYROREDOX® system where the NOx coming from the kiln get further reduced and formation of Fuel NOx is suppressed. 4.2 Dust Free Circuits: Today most of the plants face the problem of fugitive emissions as well as point source dust spillage .As is well known that the KHD COMFLEX grinding circuits are dust free circuits with no belt conveyors in the grinding and separation group. Also due the compact arrangement The system has less vibration and hence less noise level. Air chutes avoids mechanical conveying in the grinding circuit and can take feed of more than 1000 tons per hour and accepts even coarse and moist fresh feed. The Air- Chute consists of an inlet- and outlet section, each with air lock, the standard sections, the air supply and venting. From its dimensions the housing is similar to an air slide. Wear protection plates are used instead of cloth for low maintenance operation. Simple air-slide fans are used introducing ambient air or hot air, if moist materials are conveyed. 4.3 Low Water Consumption : Water consumption in cement plants is a necessity which plays a role as process water, Recirculation water and potable water. In context of the grinding systems vertical raw mills require additional water for bed stabilization and water sprays into cement mills for temperature control by evaporative cooling. This is not the case in Roller Press as water requirement is very insignificant, max 1 m3/hr in comparison to VRM Requirement of 8-10m3/hr .When a cement plant is located in a desert environment the process have to be specifically designed to have low water consumption. Hence KHD Roller Presses come in picture as the best water conserving machines 5.0 Efficiency: Definition, Concept & Measures Best operating Practices, Efficient & Reliable Equipments and Plant availability are the parameters which define the efficiency of a cement plant. In increasing competitive global cement business environment, opportunities to reduce production costs, emissions without negatively affecting product yield or quality are need of the hour. Successful, cost-effective solutions in energy efficiency & green technologies and practices often include additional benefits such as increasing the overall productivity. Energy efficiency is an effective strategy to work towards the so-called triple bottom line that focuses on the social, economic and environmental aspects of a business. KHD is contributing by integrating the best technology and point approach to supply an efficient plant in long run. Following are some of the areas where KHD technology stands apart in terms of efficiency 5.1 Efficient Cyclones: The top stage twin cyclones as supplied by KHD are designed with highest dust collection efficiency of >96%, low exhaust gas temperatures and low pressure drop. 5.2 New Clinker Cooler Static Inlet & Grate plates: KHD has further developed its Clinker cooler ‘Static Inlet’ with state-of-art features. Latest generation clinker cooler “Static Grate” is designed