Saturday 16 June 2012

New pack testing

Todau I assembled a new catalyst pack with the following composition:

SS = Inert Stainless Steel Mesh
SM = Silver Mesh
AC = Anti-Chanelling ring

THROAT
10 x SS
5 x s
1 x ss

5 x s
1 x ss
5 x s
1 x ss
for i in range (2):
   AC
   1 x ss
   5 x s
   1 x ss
   5 x s
   1 x ss
   5 x s
   1 x ss
   5 x s
   1 x ss
4 x ss
INJECTOR

I tried 2 runs of this new pack today in the stainless engine with a 8.5mm throat. The first one was really just a break in run with 800ml of %90. I started with a really slow flow rate and increased. A few times liquid peroxide squitrted out so I backed off the flow rate. The exhaust of the first pure silver pack was clear at this stage (after 800mL) however the exhaust of this new pack was still quite cloudy so I loaded another 2L and tried again. After some time there was no liquid in the exhaust but it was still really cloudy. I was clear that the pack wasn't completely catalyising so I decided to stop the test as to not waste the rest of the peroxide. The thrust seemed promising, about 7Kg but it was difficult to determine accurately as I was only pulsing the engine and it was bouncing around allot.

It seems like this new pack can handle a much higher flow rate than the pure silver one, although this could just be because it is not catalysing fully. I didn't actually compress the pack as I was assembling it, although it did compress slightly when putting the injector on the engine. Tomorrow I intend on adding another 25 silver layers (interleaved with stainless as above) and compressing firmly before trying again. If I get time I might try a run with just compressing (before adding 25 extra laters) to see what difference that alone makes.

Now that the pack can handle higher flow rates it would be really useful to add a jet/oriface to limit the flow of peroxide; this will help limit flooding of the engine at startup, although hopefully once the pack breaks in this won't be as much of an issue.

I have started just filling up the run tank directly (by taking off the valve/stem) instead of using the vacuum system. It is actually quicker and I believe safer as it reduces the number of handling steps and chance for impurities to get into the system. Also we can fill the tank in the clean area instead of outside.








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