Chapter 7 - Fuel handling systems

Abstract

This chapter examines the different methods of fuel handling that are incorporated in industrial combustion systems. For gas, usually provided under pressure at the factory gate, the fuel handling system consists of pipes and one or more valve train assemblies. For oil, the system is more complicated and requires storage tanks, normally with heaters, pumping and heating units, pipework and valve train assemblies. Coal handling and firing systems are much more complex than either oil or gas handling systems and require a great deal of mechanical handling plant. To handle gaseous fuels, gas valve trains are installed in most industrial systems. Fuel oil is an emulsion and it is stored at the lowest practical pumping temperature to prevent it deteriorating. The heaviest oils require continual circulation by pumping to prevent them from solidifying in the pipework. The oil is therefore pumped from the tank to the burner(s) around a lagged and trace heated ring main. Since coal is generally cheaper than either oil or gas it becomes the economically preferred fuel where the ash and trace chemicals can be accommodated by the process. However, a pulverized coal firing system is both more complex, and more hazardous, than other fuel systems. Often the waste is used as a supplementary fuel, and thus only represents a proportion of the total heat input. In these circumstances only limited capital is normally available for the waste fuel handling system. Most of the fuel handling techniques is fraught with dangers and flaws and yet it is one of the most important aspects of industrial systems.