Cement Energy and Environment

3.0 Proposed Up gradation 3.1 System Basic Requirement A de-dusting system of following basic specification is the requirement of new venting system: I Description Operating Parameters Air Volume Static Pressure Drop across venting system Operating Temperature Outlet/Stack Emission 3.2 Proposed Options 37000 Nm 3 /hr (54500 m 3 /hr) 120-150 mmWG 100-110 °C $30 mg/Nm 3 Following four number options have been evaluated for the new proposed cement mill venting system: Option 1: Conversion of existing ESP into Bag filter: - In this option , the existing ESP system shall be converted to bag filter to handle entire air volume of 37,000 Nm 3/hr (54,500 m 3/hr) from cement mill outlet. However, modification/ extension of existing ESP casing if required is to be carried out for accommodating the filter bags and accessories for the proposed capacity. A retrofitted bag filter, new bag filter fan and a new bag filter stack are to be installed to meet the required air flow of 54,500 m3fhr. It is to be noted that existing bag filter system will be in operating mode when the proposed retrofitted system is under execution and cement mill may run at around 50% output. Option 2: Installation of full capacity (54,500 m 3/hr) new bag filter system adjacent to the existing ESP: - In this option , a new bag filter shall be installed adjacent to existing ESP to take care of the entire cement mill vent gases of 37,000 Nm 3/hr (54,500 m3/hr). It is to be noted that existing bag filter and ESP will be in operation during the new bag filter system installation hence no production losses is envisaged. Option 3: Conversion of existing ESP into a hybrid filter system: - Hybrid filter is a combination of an ESP and a bag filter in the same casing. As the existing ESP is of lower capacity and can handle 35,000 m 3 /hr as compared to the total gas volume of 54,500 m 3 /hr, the suitability of the extension of existing ESP casing has to be checked to accommodate the bags for the proposed capacity of 37,000 Nm3fhr (54,500 m 3 /hr). A new bag filter fan of suitable capacity and a new stack has to be erected. Option 4: Retention of existing bag filter of 30,000 m3fhr and Installation of adjacent new bag filter of 30,000 m 3 /hr: - In this option, a new bag filter of additional capacity 30,000 m 3/hr will be installed adjacent to existing ESP to take care of additional venting air requirement in addition to existing bag filter of 30 ,000 m3/hr. This 30,000 m 3 /hr bag filter capacity has been selected to keep the inventory at a minimum level for new bag filter.Mill can be operated at full capacity during execution of the project as ESP and existing bag filter both will be in operation till the new bag filter comes into operation. Existing bag filter which is designed for 50mg/Nm3 is already running at dust load of 35-40 mg/Nm3 as per the data received from plant. Hence, further reduction (from 40mg/Nm3 to <30mg/Nm3) may be ach ieved by minor modifications ? -~- I