Redesign and construction of a small scale biomass and waste oil hybrid powered incinerator toilet:

Abstract

In response to the reinvent the toilet height challenge, a mobile incinerator toilet has been designed to address the inaccessibility of disabled people in Buwali camp and urban slams to available toilet with their consequences .AS an emergence sanitation mean to avoid open defecation, the designed incinerator toilet is simple, cheap, can be assembled and disassembled, environmentally friendly and efficient for treatment of human faeces. The designed incinerator toile is made up of biomass chamber with a combustion chamber area of 2100mm, seat metallic box, incinerator pot/shelf that carried the fecal matter during incineration, 310mm height chimney, strong pipe used for steam and gas channelling from the incineration pot back to the combustion chamber that increased combustion efficiency, steam reduced emissions of nitrogen oxides significantly with low carbon monoxide when using waste oil and biomass as a heat source. The pressure gauge was installed for pressure regulation to avoid bursting of the incinerator pot during the incineration process, the primary combustion zone operated at an air fuel ration slightly higher than the stoichiometric air-fuel ratio. The method of heat transfer was convection and conduction, the insulation of the biomass chamber with clay reduced heat loss to the environment. The simulation of heat transfer predicted the heat transfer rate by convection through the design prototype up to maximum temperature of 723 when biomass was used and 833k when waste oil was used. The prototype was tested at Busitema University Engineering Workshop and laboratory tests were conducted from National Water and Sewerage Corporation, Tororo Laboratory. The heat reduced the mass of fecal waste by 92.0% when using the biomass chamber for treatment while it reduced by 94.6% when using waste oil and both burners eliminated pathogens concentration with a high efficiency. With an initial investment 1,335,000 UGX, a Net Present Value of 7,320,016.788 UGX can be realized by this project with savings of 243236UGX per year.