Talk:Locally manufactured thermostatic valve for water pasteurization: Difference between revisions

Since this page hasn't been created ill get it started.... If you find a usefull like post it in here so that we can all look at it.

Hey guys! How perfect, I was just about to make this page so I could post an interesting study I found. For whoever was looking into waxes, you can find it through the library website, it's called "Study on Influence Factors of Thermal Hysteresis in Paraffin Actuator". I turns out that waxes expand a lot when they melt. The study is trying to lessen thermal hysteresis which is when a material's properties differ when they heat over a certain temperature range than when they cool over the same range. It's a study that is absolutely applicable to our project, so feel free to check it out. If we were to use melting wax, we would need to use a spring to push the piston back into position, this study looks at different springs effects on paraffin wax's thermal hysteresis. Anyways, that's all I wanted to post. -Sarah

• I found this book on knovel "Engineering with Rubber - How to Design Rubber Components (2nd edition)" In the appendix it talks about the expansion coefficients of different rubbers. Polyisoprene is natural rubber so i think if we did use a rubber it might be that one. Also that wax stuff sounds promising.
• This web site also lists a bunch of thermal expansion constants in 10-6 m/m K. Rubber has 77 10-6 m/m K. Still dont know at what temperatures though.

http://www.engineeringtoolbox.com/linear-expansion-coefficients-d_95.html

• This web site will calculate the linear thermal expansion of something if you know the expansion coefficient. If rubber is 1m at 25C and its heater to 75C then it is 1.004m. Im hoping wax will expand more than that. http://www.engineeringtoolbox.com/linear-thermal-expansion-d_1379.html

Reid