Dear all

I am already involved with the Solid-liquid mixing project and needs to determine the Just suspension speed. Many methods can be found through the handbooks and publications to define it but I am going to talk only about observation method through the bottom of the tank equipped by the mirror. There are two way to define the Njs by this method. One is that u need to increase the speed until all solid lift up and then decrease the speed till the point that the particle are still suspending through the tank. On the other method, you can gradually increase the speed, wait for 10 minutes and again increase till all the solids lift up. I have tried both of these methods but the results are very different. It will be highly appreciated if any experienced researcher in solid-liquid suspension can give me some advises to define it in correct way.

Thank you very much , in advance.

Regards

Reza