Making a mark with government project

Introduction:

Clair successfully installedPulse Jet Bag Filter based on Optiwave Long bag Technology in 2021. The scenario included replacing the existing Kiln ESPwith a new bag house for government client located in Telangana. The New Kiln Bag house of 7.2 Lakh m³/hour gas volumes was commissioned by us on EPC basis (including Civil Works). Amidst peak COVID and monsoons in India, this project was delivered in record 5 months from start to commissioning including erection.

After having a site visit, the following was summarised:-

Existing system:

• The existing Kiln of 3,000 TPD capacity had two streams of conventional cyclones on preheater, having two separate preheater fans, the delivery ducts of both the preheater fans were combined and the combined duct was routed to Gas Conditioning Tower
• In GCT, there are 12 water nozzles to bring down the temperature of preheater outlet gases from 380 – 430 °C to 250 -150 °C as per the requirement. GCT outlet common duct is again divided in two parts – one duct to VRM (Vertical Roller Mill) and other directly to ESP when VRM is not in operation
• When VRM is in operation the PH fan out gas temp of 400-430 °C is reduced to 220-250 °C in GCT and then enters into the VRM to dry up wet raw materials
• The outlet temp of the VRM is kept 95- 100°C temp. When VRM is not in operation then the PH fan outlet Temp. comes around 390-430 °C which is reduced in GCT to about 150 °C before entering into the ESP under normal Kiln operating temperature
• The existing ESP is designed for an outlet emission of <100 mg/Nm³. The proposed replacement of existing ESP to bag filter needed to be designed for an outlet emission of ≤ 30 mg/Nm³

Proposed System:

• Bag filter has been designed for an outlet emission of ≤ 30 mg/Nm³
• Ducting from the Kiln GCT inlet (Pre-heater outlet) for direct operation
• Ducting from the Raw Mill vent fan outlet duct for compound operation. Both the ducts merged and joined to the ESP inlet duct at +19mt level
• The inlet duct to the Bag filter tapped near the present ESP inlet and joined to the new Bag filter
• Outlet duct from the Bag filter to the inlet of bag filter ID fan and Outlet duct from the bag filter ID fan to the existing stack
• Collected material from bag filter has been designed to convey the material to the existing conveying system of the VRM circuit

Since the commissioning of the bag filter, the system has been running successfully achieving the desired emission levels, lower pressure drop and compressed air consumption. The operating parameters of the bag filter have been provided in the Table 1.

Data/ Table:

Table 1:Technical specifications of OWPC based long bag filter

Observations:

The challenges we faced:-

• Current ESP designed for <100 mg/Nm³ emission was reduced
• Multiple duct nodes between 2 preheater fans, Kiln GCT, VRM and ESP were optimized
• Only 5 days Kiln shutdown amidst monsoon season and Covid-19 restrictions, all activities to be completed during shutdown
• Project start to commissioning of Bag House completed in record 5 months on EPC basis, including civil works

The Key benefits of post installations:-

• Particulate matter emission was reduced from <100 mg/Nm³ to ≤30 mg/Nm³
• Reduced consumption of compressed air
• Reduced consumption of power
• Only 5 days of Kiln shutdown (hook-up period)

Pictures: