[SS-Propellant] Casting Apparatus-- Heating

[Rich Nakka]

Hi Rich,
Thanks for the input...

Rich Hansen wrote:

> Hello,

> They make heating mantles used in chemistry that would do exactly what 
> we need.  I've looked for pricing on models for a 3 liter container 
> (sufficient for a 3kg batch size by my math?)

The heating tanks should have a capacity greater than the mixing drum by 
a factor of at least two. The intent is to replenish them continually 
and heat up the contents while the mixing drum is doing its thing.

> and it appears to vary from ~200 dollars to several thousand.  We 
> would want one that has a hole in the bottom, to facilitate the 
> draining of the liquid-- I'm still checking around on pricing.  We 
> could control the temperature fairly well automatically with a 
> temperature probe tied to a PID loop controlling the power (many 
> models operate on a 4-20 ma signal), or manually with a thermometer 
> and variable power supply, in keeping with the KISS principle.

I wouldn't put too much emphasis on KISS. After all, where safety is 
concerned, "stupidity" has no place.

>  
> Or we could wrap the vessel in nichrome, or resistors, or whatever.  
> We'd need to develop and test a temperature control scheme in this case.
>  
> As far as stirring goes, I think the idea of a motor connected to 
> paddles is good, although I envision a downward facing cone 
> shaped container as the main mixing box, with the motor at the top and 
> a shaft down through the center, with paddles attached, and a drain to 
> the mold on the bottom.  We could shape the paddles so they push the 
> slurry down.  I will draw a sketch tomorrow.

Great, keep the creative juices flowing...

>  
> In any event, if we can find cost-effective heating mantles, I think 
> they are the way to go.  Please comment on the above.  I am assuming 
> our budget is 'as cheaply as is safe'.

I think building the heating tanks, etc.  from scratch would be far more 
cost effective and within our "budget".
By the way, I am working on a specification document for the propellant 
casting  process that will (it is hoped) form a rational basis for 
design of the complete system. The draft should be ready in about a 
week. This weekend I was sidelined working on the experiment related to 
the evaporation method under vacuum. Went quite well...full report 
coming soon.

Richard

Richard

>  
> Thanks,
> Rich Hansen
> rhansen at mc2inc.net <mailto:rhansen at mc2inc.net>
>
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