Another test with different thresholds

A project log for vapsy

A tiny vapor phase reflow oven

ChristophChristoph 10/08/2015 at 07:130 Comments

Some more threshold temperature checks were implemented (my plan was different but I had an error in the implementation. The power should be higher, and these are the actual values):

This is the result:

It's obvious that the lowered power isn't enough to compensate for losses through the insulation and evaporate more galden. Some more galden is evaporated, but the slowly rising temperature in the chamber indicates that there's still not saturated vapor in there, but an air-vapor mix below 230 °C. If it was saturated vapor it would have the evaporation temperature of 230 °C.

So I changed this a bit:

Things were a bit different now:

Now there's saturated vapor in the chamber at about t = 220 s, and a short while later the chiller outlet temperature jumps to some 90 °C. This jump could be anticipated, because some evaporated galden condensed in the chiller inlet tube, which has a short horizontal section just behind the chamber. A galden drop built up here, basically obstructing the outlet until too much galden evaporated and suddenly a lot of it got into the chiller.

The chiller reacts quickly to the increased galden mass flow, and also shows fast recovery from such a "flush".