[SS-Propellant] [Fwd: Propellant casting schemes]

[Rich Nakka]

dormans wrote:

> ... I think that we need to make the decision based on, in order of 
> importance, 1.Saftey, 2.Quality, and 3. Ease of production.
>
I tend to agree with you. Something else to bear in mind...if we get 
media attention (e.g. some sort of documentary/whatever that had been 
discussed earlier), we should be extra wary of this procedure with 
regard to level of safety & level of sophistication.

> That being said, my vote is that we move forward with the Krech/Nakka 
> method.  My biggest concern with this method is that there seems to be 
> the potential to lose a lot of heat in steps 2 and 3, which could 
> cause us trouble in step 4.
>
You are absolutely right. Step 2 shouldn't be too bad, a good insulation 
system should minimize heat loss. But with step 3, evaporation requires 
energy, and without heating,  a severe temperature loss would result. I 
did the calcs earlier, and found that a 500 watt heater (min.) would be 
needed to maintain a constant temperature of the slurry (2 kg.).

> Not a huge problem. The other thing that scared me about this method 
> was seeing the note that estimates the required time to produce 12 
> segments is 4.75 days. Seeing the number is a bit daunting, but 
> realistically I think that any method that we use will take 
> approximately the same 4 or 5 days to complete 12 high quality segments.
>
Yes, that scared me too. But I believe that a signficant time reduction 
should be possible. For example, increasing the batch size from 2kg to 
3kg should reduce the processing time to roughly 2/3. A good suggestion 
was made to continually replenish the sorbitol & KN/H2O tanks. This I 
think is a great suggestion that'd cut down production time alot. Also, 
I believe we should use 2 processing stations, this could cut the time 
in half  The main reason, however, is for redundancy, in case one 
station should suffer a major (irrepairable) malfunction.

>  
>
> I also still like the Vrbec Method based solely on the fact that it is 
> a method that most of us have experience with.  The potential for a 
> mishap with this method would have to be well addressed though.  
> Perhaps a simple test to see the effect of an unexpected ignition of 
> some quantity of finely milled and well mixed powdered propellant in 
> an open container would give us an idea if this was a method that we 
> wanted to pursue or not.
>
Indeed, this is the method we are drawn toward for reasons of comfort 
(tried & true). Your suggestions about testing the effects of ignition 
of a large batch of powdered propellant  (or hot molten propellant) is 
an excellent one ...I will add this to the document of PDT 
investigations, in fact. That should be a fun experiment =-O ...!

Richard

>  
>
> Randy Dormans
>
>  
>
> ------------------------------------------------------------------------
>
> From: ss-propellant-bounces at exrocketry.net 
> [mailto:ss-propellant-bounces at exrocketry.net] On Behalf Of Rich Nakka
> Sent: Saturday, January 14, 2006 9:40 AM
> To: Propellant Development Team
> Subject: [SS-Propellant] [Fwd: Propellant casting schemes]
>
>  
>
> Greetings, Propellant Development Team members,
>
> There hasn't yet been any feedback from the team as to which 
> propellant productions schemes we should pursue. I expect we should 
> narrow the list down to a couple of schemes, and do whatever followup 
> investigation/testing that is necessary to finalize the choice to a 
> single one. Or perhaps none of the schemes presented is worthwhile? 
> Other ideas?
>
> Once again, the link to the document is here:
> http://www.sugarshot.org/downloads/ssts_propellant-schemes.pdf
>
> Feedback, please...!
> Time is fleeting....!
> Richard
> --------
>
>
> -------- Original Message --------
>
> Subject:
>
> 	
>
> Propellant casting schemes
>
> Date:
>
> 	
>
> Sat, 17 Dec 2005 23:10:17 -0500
>
> From:
>
> 	
>
> Rich Nakka <richnakka at rogers.com> <mailto:richnakka at rogers.com>
>
> To:
>
> 	
>
> Propellant Development Team <ss-propellant at exrocketry.net> 
> <mailto:ss-propellant at exrocketry.net>
>
>  
>
>Greetings, fellow Propellant Development Team (PDT)  members,
>
> 
>
>I am sure you have all been closely following the interesting 
>
>discussions about proposed propellant casting schemes.
>
> 
>
>I've summarized the schemes in the following Word document:
>
>http://sugarshot.org/downloads/ssts_propellant-schemes.doc
>
> 
>
>I would appreciate if each PDT member could read over the document and 
>
>make comments including pro's and con's of the various schemes. Once 
>
>comments  has been compiled, we can then take the next steps in 
>
>assessing the schemes and trying to narrow down one or two that we can 
>
>invest more effort in studying greater detail.
>
> 
>
>Please return marked up docs to me by Wed. Dec.21st evening, at the 
>
>latest. I will be gone on vacation after that and I plan on taking the 
>
>feedback with me, to peruse and summarize, while on holiday.
>
> 
>
>cheers & thanks
>
>Richard
>
> 
>

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