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Registered Member #2431
Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639
hen918 wrote ...
Patrick wrote ...
I think the pump was an oversight on my part.
....
Aluminum, copper, unknown steel and plastic, sigh.
i think its on to the peristaltic pump type.
it looks like a little gear pump to me. A peristaltic pump has one continuous flexible tube (sometimes the same tube that supplies it), a cam flattens the tube turns, forcing the liquid through the pump. A peristaltic pump would be better for lower contaminants, but would probably have a lower flow.
yes its a tiny gear pump. Ill use a peristolic without fittings just super-soft silicone RC engine tubing. Im looking at the flow requirements too.
the real issue is equal flow trough out the paralleled flow channels. I dont want to put in artificial restrictions in as we would with resistors.
EDIT:
I measured the dry resistance of the 4mg^2 Pl/B side. It was 2.6 ohms per 0.95 inches. the 4mg^2 Pl/Ru side is so close as to be the same i think.
this tells me that the carbon cloth really controls absolute resistance. But i measured across almost an inch. so reducing resistance means more contact area with out blocking surface area. Thinness of the carbon layer also matters. A single side of the cell is 0.03".
Registered Member #2431
Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639
This is a great PDF, i cant find many like it do to pay-walls, and i can get e-books and research materials from chico at the moment since im not an active student.
i dont know if it needs to be restrained or not ? or if the Naifion can be epoxied to or not.
Registered Member #65
Joined: Thu Feb 09 2006, 06:43AM
Location:
Posts: 1155
This covers the general idea of a pile, but does not include documentation about coolant manifolds.
The stack up is usually made of many cells bolted together into a single block to get the low cell voltages up to usable levels. Local units that were tested on buses (later converted back to diesel due to operational costs) used relatively thin H2 fuel distribution manifolds that looked similar to water-jet cut stencils.
Also, recall most stainless includes different percentages of nickel (a catalyst itself under some conditions), and often 316L is more corrosion resistant than the common 304 style grades (that can get rust spots more easily if the oxide layer is damaged, or galvanic corrosion occurs with other contacted metals). I don't think it should pose a problem for your set-up, but it should be documented somewhere if these are going to be used long term.
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Direct Methanol Fuel Cell Project.
