EXPERIMENTAL ANALYSIS OF EXCHANGER FIN TUBES TO INCREASE FURNACE PERFORMANCE
In many process industries requirement of heating is achieved by most traditional means that is fired heating. Equipment set ups ranging from very small to gigantic are put in place for same. Cracker furnaces are one of them. Main task achieved by cracker furnace is heating process fluid to its cracking point. The equipment consists of various parts mainly furnace and convection modules. Furnace is lower part of the equipment and serves primary purpose of cracking process fluid. On the other hand convection modules are designed to absorb waste heat set free out of furnace after cracking process fluid. Other parts of the furnace are furnace coil and convection module coils which provide enclosed passage for fluid to be heated during heating. Further to this there are components like breaching and stack. These are passages for exit of flue gases at lower temperature to environment. Breaching and stack are designed such that they provide necessary suction for exit of the flue gas. In later stage requirement of preheated air for burners was observed. Burners are used to burn air gas mixture inside the furnace. This project deals with the experimental study and examination of heat transfer from extended pipe surfaces of different shapes. The finned pipes are to be used in an auxiliary unit where ambient air is preheated and supplied to mix with gaseous burner fuel. The process is to be done at lower temperature flue gases and flue gases are again deposited in main exit stream without affecting significantly on suction capacity of stack hence overall performance. There is generic option of designing circular fins on the pipe surface and achieve heat transfer. In this experiment fins of two more geometrical shapes have been designed equivalent in all respect to circular fin (except geometrical shape). The fabricated models are put under same conditions and observed for heat transfer from surface and fins to find out maximum heat transfer. The project investigates different shapes of fins in context of heat transfer considering natural convection. It is observed that the triangular fins have slightly higher tendency to transfer heat to surrounding than other two shapes. Scope of different fin shapes in applications other than auxiliary heat exchanger is discussed in short. Keywords—finned tube, hear transfer, natural convection, furnace, auxiliary heater