Stirring fan melting

[Frederic_Lapierre]

Hey, I had an issue in our last experiment; some parts of the the stirring fan seems to have melted a little. It still works but I want to make sure what could have caused this.

For us, it is really important to check the stirring regularly, so we removed parts of the casing, so we could get a look into the bioreactor. However, I wanted to ask if this could have resulted in the temperature regulation not working well, as the temperature sensor then would not measure valid temperature levels inside the reactor, resulting in an overheating of the heating system.

Or maybe some other issue could have caused this?

The reactor did not overflow!

Thank you very much for your help! 🙂

[harrison]

Hi Frederic,

That is a little worrying.
The temperature sensor shouldn’t perturbed by this.
What CAN cause this is if you run the reactor without the glass test tube (with liquid in it) fully touching the heat plate at the bottom. In that case there are few ways for the heat to be conducted out and the heat plate gets very hot -> Can melt the fan.
I would therefore be cautious to ensure you ALWAYS ensure you push it righ to the bottom (should be able to hear a little clink when glass touches metal).
Note some poeple have made custom lids in the past which broke this feature – i.e. the “arms” on the lid pushed up against the screws on the top side of the reactor before the glass reached the bottom. Consequently there was always an air gap there and these heating problems happened. So, make sure your lid isn’t causing it (e.g. by pushing it all the way down with the lid arms not aligned/on the screws and see that it goes down the same distance as when they are on the screws.
Hope this makes sense
Harrison

[Frederic_Lapierre]

Hi Harrison,

thank you very much for the reply!

We did in fact had to make some adaptions to the lid so it’s indeed very likely that this was the issue! We don’t hear this clink sound anymore with this system. I will check if this is the issue.

Best regards,

Frédéric

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