glue-itcom
Well-Known Member
- Joined
- Apr 10, 2013
- Messages
- 216
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With the tiny vertical boiler I made I managed to estimate the thermal conductivity of the multi-layer insulation:
This insulation had a reasonable thickness of around 4mm, hence the overall insulation was rather good.
With the miniature traction engine I'm making I need to shrink this insulation down to ~1.5mm in thickness. The multi-layer insulators that were originally design to keep liquid hydrogen cold are interesting as the thermal conductivity is several orders of magnitude better than this. However, you still need enough space to isolate the layers.
So I have made a new boiler thermal test object to try some different approaches.
I have just tested:
I'm thinking of trying perforated paper and hence add air pockets and reflective foil. Also, I need to try a thin sheet of silicon.
However, I would be interested in ideas for testing.
- Teflon sheet – a thin baking sheet wrap
- Medium weight paper wrap
- Polythene – this was a thick clear polythene bag
- Medium weight paper wrap
- Air gap – created using thin wood veneer strips
- Bog oak outer layer
This insulation had a reasonable thickness of around 4mm, hence the overall insulation was rather good.
With the miniature traction engine I'm making I need to shrink this insulation down to ~1.5mm in thickness. The multi-layer insulators that were originally design to keep liquid hydrogen cold are interesting as the thermal conductivity is several orders of magnitude better than this. However, you still need enough space to isolate the layers.
So I have made a new boiler thermal test object to try some different approaches.
I have just tested:
- Teflon
- paper
- aluminium foil
- paper
- aluminium foil
- paper
- Brass outer wrap
I'm thinking of trying perforated paper and hence add air pockets and reflective foil. Also, I need to try a thin sheet of silicon.
However, I would be interested in ideas for testing.