Manufacture of porcelain insulators from locally available materials

Abstract

This study discusses the local production, electrical characteristics and performance in service of porcelain insulators for outdoor low-voltage apparatus. Concern was given to the identification, beneficiation, characterization and utilization of locally available raw materials in Nigeria for the production of electrical porcelain insulators, taking benefits of the availability of these raw materials. The process control presents figures, tables, simulations. The basic raw materials were separately prepared using a 200-µm sieve. The composition of the triaxial constituents was varied to produce samples for testing. Altering the percentage content of silica and the alumina recorded a change in the mechanical strength and the sintering temperature; this was handled by adding fluxes suitable for improving tensile strength without increasing sintering temperature of the paste. Porcelain slab samples of different triaxial composition were formed. Tests on mechanical resistance, porosity and water absorption were carried out. Sample A, with specific percentage composition of 38% feldspar, 18% quartz, 32% kaolin and 12% ball clay, was used to produce porcelain suitable for the 480 V pin insulators. The produced sample possess an electrical dielectric constant of 9.80, a dissipating factor of 0.060, flashover voltage of above 5 kV all at 50 Hz of supply voltage frequency and a mechanical load support of 13.85 kN.