Eventos Anais de eventos
COBEF 2017
Congresso Brasileiro de Engenharia de Fabricação
Viability study of production of enclosed impellers for centrifugal pumps by investment casting process
Submission Author:
Gustavo Augusto Massaro , SP
Co-Authors:
Eugênio Zoqui, Davi Benati
Presenter: Gustavo Augusto Massaro
doi://10.26678/ABCM.COBEF2017.COF2017-0543
Abstract
Centrifugal pumps are used to transport fluids and can operate continuously for long periods. Thereby, the increase of efficiency can generate significant reduction in energy consumption. The motivation of this work was the development of better alternatives (manufacturing processes, design and materials) for the production of hydraulic centrifugal pumps aiming to increase the hydraulic efficiency and reduce the operation costs due to the improvement of the standard quality of its components. This work describes the design, production and testing of enclosed impellers manufactured by investment casting process from ASTM A216 Grade WCB steel and a comparison concerning quality, efficiency and costs with enclosed impellers manufactured by conventional sand casting process from ASTM A48 CL30 gray cast iron. To establish benchmarks, the following tests were performed: roughness, weighing, dynamic balancing, centrifugal pump performance, chemical composition, micrograph, wear and hardness. Investment casting process could allow the development of a new enclosed impeller design with small fluid passages and the switch to higher mechanical properties materials (i.e., steel versus cast iron) that supported the structural changes imposed by the new design. Impellers manufactured by investment casting presented better surface finishing, more microstructure homogeneity, less initial imbalance and higher hydraulic performance when compared to impellers made by conventional casting. Despite the higher production operating costs, the impellers manufactured by investment casting presented final manufacturing costs practically equals that of conventional casting when the finishing operations are considered. Thus, the increasing of hydraulic pump efficiency and consequently the savings in pump power consumption during operation demonstrated the viability, in terms of costbenefit, of production of enclosed impellers for centrifugal pumps manufactured by investment casting process from ASTM A216 Grade WCB steel.
Keywords
impeller, centrifugal pump, precision casting, investment casting, lost-wax casting, hydraulic efficiency
