A Study on Evacuation Performance of Siphon-Type Water Closets

摘要

Many designs of sit-type water closets have been in the market. Different design uses different mechanism to bring down the waste. One of these many designs utilizes siphon effect to flush, therefore is called siphon type. This type of water closet has simple structure and is very widely used at home. To obtain good flush effect, water volume for each flush is crucial. However, it is limited to no more than 6 liters by government regulation in many countries. It is a common sense that the water passage in the closet affects the flush effect. This research uses 3 different passages, a commercial existed one and two others to compare how the flush effect varies at different water volume and different passages. Tests were used to examine the evacuation effect and flow velocities of water in passages were also measured by particle tracking technique. Observations indicate air is always trapped in the passage. The passage creates better evacuation effect contains fewer air trap and completes a flush process at less time span. A correlation based on non-dimensional parameters based on water volume and flush time and geometry dimensions is also constructed. A diagram established according to these non-dimensional parameters depicts different regions for good and poor flush performance.