So an up-market commercial hair drier is not really sufficient.What is that hole on the joint ring? The colour looks a bit like something was soldered there, but... I'm colourblind.
Maybe I'm also blind because I don't see the screws saxcop referred to (I assume they meant the joint ring screws like "modern" saxophones have for a removable ring).
Some models had a glued joint in spite of not having a removable ring and I think Vitos made in Japan had those, but a Beaugnier made one is likely to have a soldered joint.
It is possible it was changed at some point though. Usually it's possible to see if this joint is soldered but you need to know what to look for.
If it's glued with epoxy or any similar glue then you can heat it to about 150C. You need it to actually get to that temp, so using a 150C heat source is not really hot enough.
If it's soldered then most soft soldered melt at around the 180C to 220C range. In this case you need to have the entire joint more or less at that temp, so not only you need the hotter heat source as before, you need it significantly hooter to get the entire joint atl east that hot at the same time (before part of it cools too fast while you heat another part).