DESIGN, CONSTRUCTION AND TESTING OF A LOW FLUSH TOILET

ABSTRACT

Water and sanitation are key agendas for continued and sustainable development of any economy. Water has over time been viewed as an infinite resource, one that is abundant in nature. However, clean water that is safe for human use is a limited resource. Water shortage has become a troubling menace in our cities. Research shows that a flush toilet fixture comparatively consumes the most water in households. Number of flush toilets has increased in homes and hence an increased strain on clean water supply. Our project was dedicated to designing a toilet that consumes 6 or less litres of water per flush, construct a model and test workability of the concept. In our research, we sort to change water flow patterns from the sump by creating an easier path for waste to flow. This was done by removing the trap way. Excluding the trap way from our design necessitated we find a way to maintain the water seal that prevents noxious gases from the sewer line from getting into the house. A valve with its actuation and recovery mechanism for precision was designed.  A butterfly valve was chosen due to its ability to adapt with a circular waste pipe. Its location from the sump was defined such that the volume of water held in the sump created an optimum water spot and provided the water seal. Orientation of the drain pipe was inclined slightly from the horizontal. This provided for an acceleration coefficient for flow of both waste and water from the bowl. We also set to reduce blockage of toilet drain pipe experienced in low flush toilets due to their reduced trap way size and constrictions. This was achieved by using a bigger drain pipe. Flow parameters from the tank were modelled to suit desired flow rates such that the water seal was always maintained. Dimensions of rim slots and their angle of inclination were specified such that cleaning action was optimized. Their number was decided on so as to provided sufficient flow rate to match our calculations. A simplified model was constructed for testing. Performance of the design was tested and results captured. The test proved the working of the concept. Detailed cad drawings of the design are provided to show proposed solution. Its implementation cuts water used for flushing a toilet to 6liters per flush. With automation, it provides for use of even less water per flush. Our design would help reduce water usage in every household and help more people conserve water in order to sustain the entire population in our country.