International Journal of Academic and Applied Research (IJAAR)   Year: 2022 | Volume: 6 | Issue: 5 | Page No.: 196-200 Application of Decision Matrix for the Selection of the Best Conceptual Design for a Small Scale Solid Waste Fired Steam Boiler Download PDF Olisa Yemi, Kotingo Kelvin and Fadayini Oluwafemi Abstract: The evaluation and selection of the best conceptual design for any machine or equipment based on some decision criteria, often present some difficulties to engineering designers. This work presents the application of decision matrix for the selection of the best conceptual design for a small scale solid waste fired steam boiler. Applying the concept of decision matrix enables engineering designers and students to provide more accurate decision about problems involving conceptual design according to some given criteria. Different conceptual designs of the boiler were generated vis-a-viz: fixed grate with circular tube, fixed grate with stepped tube, moving grate, rotating grate, step grate and modular boiler. The criteria used for selecting the best small scale solid waste fired steam boiler, using the weighted decision matrix, were based on the following: waste treatment, energy recovery efficiency, manufacturability, feasibility, cost (planning, materials and construction), safety (environmental and direct health risk) and operational cost. The result reveals that the best conceptual design was the stepped grate which had a weighted score of 930 followed by the moving grate, fixed grate with stepped tube and fixed grate with circular tube having weighted scores of 830, 790 and 780 respectively.