ASSESSMENT OF HEAT TRANSFER EFFECTIVENESS - APPLICATION TO SHELL BITUMEN PLANT, TAKORADI, GHANA

摘要

At Shell Bitumen Plant, Takoradi, Beverley Thermal Fluid Heater (BTFH) generates heat energy to heat thermal fluid (Thermia B) which flows through heat exchanger and then heats bitumen which is to be maintained at temperature range of 140 °C to 160 °C before it is discharged. High rate of heat losses have been observed and in order to maintain the temperature range of bitumen at (140 °C to 160 °C), a lot of heat energy is needed to be generated which means higher fuel consumption for BTFH. Industrial fuel oil is used to fuel the BTFH. This paper assesses the existing insulation system on the plant and seeks to improve on it so as to cut down heat losses. Consequently, the work looked at the estimation of heat losses, selection of materials for heat transfer and lagging purposes. In this wise, the existing laggings were modified by introducing fibreglass between the asbestos and masonry and thus reducing the current heat lost by 78 %. Heat from the exhaust gas which would have otherwise, gone wasted, was utilised by redesigning the chimney and this yielded 0.868 kW of heat energy to aid the heating of the bitumen. In the face of rising cost of fuel and taking cognizance of the fact that cheaper natural gas and liquefied petroleum gas could be produced in Ghana, it is recommended that the heater should be fueled by either of these gases.