Analysis of Energy Cost Savings by Insulation of Accumulator Heater in Plastic Blow Moulding Process a Case Study of Kentainers Limited, Embakasi

Abstract

Blow moulding process of plastic tank production makes use of electricity to heat the band heaters to attain optimal temperature for melting the plastic pellets which are the raw materials used in the process. Based on an analysis of the process, the major electricity consumer was found out to be the accumulator. This project investigated how much savings are gained by the insulation of the accumulator in the plastic blow moulding process. Ceramic fibre, cellular glass, calcium silicate and fibre glass were the different insulation materials analysed. Based on the comparison, fibre glass was found out to be the most cost effective, available and easy to handle hence used for this research project. This research was guided by five main objectives, namely: determination of energy consumption for existing system, identify energy losses in the existing accumulator, evaluation of different insulation materials then estimation of energy savings after insulation and finally carry out the economic analysis of the project to determine the viability of the insulation. From the research findings based on the real time data collected and recorded, there was a significant change in energy consumption per kilogram of product manufactured through the process. Estimation of energy savings was based on heat losses from the surface of the accumulator. There was an overall reduction in convective and radiative heat losses returning 4.452 kW representing a heat loss gain of 40.83% hence the insulation was a success. This is evidence to the fact that more energy is lost when the accumulator is not insulated than when insulated. The cost benefit analysis returned a positive net present value of Kes. 900,040.57 and the IRR was calculated to be 110 %. This was an indicator that the change was worth. Again, the simple payback period was 8 months and return on investment was 139.16 %. Using these four methods of capital budgeting, which are, NPV, IRR, Simple payback period and ROI the undertaking was worthwhile venture.