(107a) Online Purging Assistance Toeliminate Risk of Explosion in GCP Area of Blast Furnace

In Tata steel, various types of hazardous gases are produced as a by-product and these gases are further used as fuel in many processes. In order to maintain the integrity of gas lines, regular inspection and maintenance are required. For any maintenance activity in a gas line, purging is necessary to ensure the system is free of toxic and flammable gases.

Challenges in the previous purging process :

1) There are chances of insufficient purging of the gas line due to manual interventions like nitrogen valve opening activity and manual measurement of gas through vents . Additionally, the skill, knowledge, and experience of the operator play a vital role in ensuring the quality of purging.

2) Conventionally, the purging process takes a long time for volume replacement in the entire gasline. The line is then monitored manually for zero ppm gas at the vent exhaust point at different locations. Purging continues during this monitoring, resulting in excess consumption of the purge gas and requiring more downtime for purging, which leads to delayed shutdown as well as startup of plant.

Purpose:

A need was felt to track real-time updates of the purging process. Tata Steel’s innovative approach on new purging assistance model was developed to overcome the earlier systemic challenges. Under this model, few set of remote operated valves have been installed at strategic locations along with provision of gas analyser at vents. Accordingly, logic and interlocks have been developed, enabling the operator to purge the whole gas line from the control room.

Unique features:

Online purging assistance is a unique concept and first of its kind in the steel industry making use of online purging assistance. Some of unique features are:

1. Real-time alert and confirmation of purging process.
2. Operational Excellence by shutdown duration reduction with enhanced safety.
3. Elimination of process incident due to inadequate purging.
4. Enhanced communication and collaboration among various stakeholders