This application used a 2604 to reduce CO (Carbon monoxide) emissions from foundries in and around Agra in India.
The CO emissions were spoiling the beauty of the nearby Taj Mahal and The Pollution Control Board instructed the local foundry owners to implement better combustion control.
The 2604 was chosen because of its maths capability. It proved very successful at reducing CO emissions within the limits prescribed by the Pollution control authorities. The molten metal produced was also of a high quality. This business was won against a competitor as their controllers failed to produce the required improvement.
The furnaces produce molten metal from Pig Iron. Three burners with gas and air flow ratio control create the required temperature. The arrangement is illustrated below.
The pressure and temperature corrected airflow was implemented using the
formula given below.
Q=A* √ (H*P/T )
A = constant
H = air flow
P = constant (Pressure)
The Air flow is controlled using the ratio derived from the Gas flow rate. If the temperature compensated Gas/Air flow ratio is not maintained, then the exhaust will contain excess CO and the oxide will be mixed in the molten metal. This gives a poor quality of molten metal, which will not form proper castings.
The air flow rate is derived from differential pressure across an orifice plate.