Case Study 7 - Float Glass plant

Waste Heat Recovery from hot gases exhausted by Float Glass Melting Furnace for Power Generation

System Description

Initial situation

• The glass melting furnace melts the glass for production of Float Glass
• Furnace capacity – 700 TPD
• Exhaust Gas from the furnace goes to stack at high temperature, through series of gas cleaning equipments.
• The heat in flue gas was being wasted in the atmosphere

Challenges

• Glass melting Furnace maintains negative pressure of -5 mmwc approx for safe operation. Slight variation in pressure can disturb the process. Heat recovery was to be done without affecting furnace operation.
• Heat recovery was required to be done in specific quantity, as the balance heat was needed for FGD system.
• The exhaust gas was dusty.

Existing Process Schematic

Solution offered

• Heat is recovered from flue gas in the form of superheated steam in Waste Heat Recovery Boiler.
• The superheated steam drives Steam Turbine Generator to produce electric power.
• Pressure drop across waste heat recovery system is exactly matched with the existing & parallel Forced Draft Cooler system.
• Suitable control system is provided to divert the excess quantity of flue gas through modulating divertor valve

Revised Process Schematic

Installation Photograph

Results