Putting it all together...
Entry posted by Swede
8512 views
This is going to be a boring blog entry... the main purpose is to show that yes, the project is still underway, and progress is being made.
The scope and complexity of this project has really grown. I'm looking at a potential rat's nest of tubes, wires, cables, etc, many of which, if they leak, could be disastrous. I think of myself as an organized guy. My wife would call me obsessed with order, and she's probably right. My chemicals are incredibly tidy, labeled with a Dymo "Letra-tag", and placed in neat rows on my storage shelves, organized by function. I have even gone so far as to print out DOT warning labels, using my inkjet printer, such as the "Oxidizer" and "Explosive", and the appropriate containers carry these homemade tags. Chemicals that are toxic or hazardous have a red "DANGER" label affixed as well. I believe it is good to have chemicals labeled correctly as much for legal and safety reasons as simply being orderly. If (God forbid) I am "raided" for doing something entirely legal, the professional labels will go a long way towards confirming serious research as opposed to dangerous nut job.
Anyway, with that disclaimer out of the way, I decided to obtain and put together a service cart to hold the system. Service carts can be metal or plastic, with the plastic being infinitely more desireable for this process... spills are inevitable. I checked out Harbor Freight first, but struck out. A nearby Northern Tool had just what I was looking for...
Outside, on a beautiful day, I put it together. Typical instructions... all pictographs/heiroglyphs except for the safety page. One entry there caused me to pause:
Damn it! Can't use a plastic cart while on drugs. These carts can be deadly! 
I put my crack pipe aside, and put the cart together. I was impressed. The plastic was exceptionally thick and heavy, and it is well-designed. This is a really solid product. Mark the Friendly Brittany kept me company.
With the cart complete, the next step was to set it up for electrical power. I am expecting no fewer than two devices at 240V (the power supply and the pump) and probably four or five 120V devices. Rather than have a slew of cables running to the cart, I decided I wanted to have just one that would carry all the juice I'll need, and further, I wanted it all to be well-protected. This meant a quality cable carried in waterproof flex conduit, and it needed its own circuit breaker (30A) in my shop service panel.
I started on the "power distribution system" first; just a fancy name for a custom power strip to ride on the cart. To get both 240V and 120V to the system requires a cable with four conductors, two each 120V (added together, they make 240V), a neutral line, and of course, a ground line. Fortunately I have a bit of surplus cable purchased long ago, and didn't have to buy any of this stuff. Cu prices have gone insane.
Be warned: Don't screw around with electricity unless you know what you are doing. I know enough to be safe, not much more. Like pyrotechnics, it is not forgiving of carelessness or ignorance. Here is the assembly before it was secured:
The brown outlet to the right is a correct 240V outlet for the power supply, but my setup here is non-standard in one area... I am using a 120V outlet fixture for a 240V appliance, the pump. The pump control was an oddball purchase from eBay, and lacking a correct power cable, I am going to use one designed for 120V. Thus, the two hot legs (plus ground) go to the three outlets, and the neutral, plus one of the hot legs, is routed to the cannibalized power strip. To make sure no one would accidentally plug a 120V appliance into the 240V outlet, I slapped a few labels on it. The wooden backing was coated heavily with (what else?) nitrocellulose lacquer, my new favorite wood finish... love the smell!
In retrospect, I wish I had primed and painted the galvanized steel with some enamel paint, but I was impatient. That is something that I need to do. Otherwise, those handy-boxes are going to corrode to hell from the fumes. No matter how well-sealed you think a system is, there is always a bit of salt creep, a whiff of chlorine, and either of those is death to most metals.
The new circuit breaker (a two-pole 30A job) was installed, and a length of waterproof flex conduit was routed from the completed power assembly to the service panel. The power assembly was bolted to one rim of the plastic cart with a pair of SS bolts.
It is finally time to populate the cart and get this thing plumbed. Earlier tests with water indicated that I needed the EC (electrode cell) to be positioned well above the CC (collection cell); thus, the CC goes on the lower shelf, and the EC will be positioned on the top. There's plenty of room on the cart, and the power supply that I am going to start with fit perfectly on the rim, at one end. It is fan cooled, so there is no problem to put additional gadgets on top of the power supply. For now, this will include the pump control, the thermocouple meter, and a pair of air pumps for electrolyte agitation.
The tentative layout overall. On the bottom is the CC; to the left is the pump. No plumbing yet, but that's simply a matter of screwing in some PVDF hose barbs, and routing the plastic tubing.
There were still a few "widgets" to make. I needed a pair of thermowells. These devices are immersed in the electrolyte, yet are still sealed and leakproof. Two of these were created from PTFE (Teflon) bar, and look like this:
Nothing more than a PTFE rod, threaded 1/4" NPT, ad with a 1/8" hole drilled not quite through. In use, the type K thermocouple is dropped into the thermowell with perhaps a dab of heat-conducting grease. One will be installed in the CC, the other, into the EC.
For quite a few days, I was wondering exactly how I could monitor the fluid levels in both cells. The EC is easy... since the pump is outputted into the bottom, and flows up, then out, all I need to do is ensure that I am visually seeing flow in the return line, dumping the hot electrolyte back into the CC. But the CC, where I am hoping massive crops of crystals will grow, was not so simple. It is 100% opaque, and with eight studs plus holddown nuts, it is not a simple thing to crack the lid and sneak a peek. Then, while messing around a bit today with all the fittings and tubing that I've gathered for this beast, it hit me... simply use a section of tubing as a "sight glass." The bottom of the sight glass is located fairly low on the body of the cell, and rises upwards, with the top vented back into the cell. The fluid level seen in the sight glass will macth that inside the cell. Now, how to make it?
I tested my 1/4" PTFE tubing, and it was easy to see the level of fluid, but of course, glass would be ideal. I've got literally hundreds of pipettes (eBay again) so I messed around a bit, and came up with a nice system, starting with a 2ml graduated pipette.
The first step was to create a 90 degree bend in the glass. This was easily done with a propane torch. It took a few tries to make it look nice, and in the end, I learned the easiest way to do it was to let the pipette droop under its own weight, encouraged by a propane torch. At the apropriate locations, the tubing was nicked, parted, and the rough edges were flame polished. Finally, the glass was annealed overall with a bit more heat.
I have a small roll of Tygon tubing that will join the modified pipette to a pair of 90-degree PVDF fittings. A picture or two is better than a description, so here it is:
The joint (pipette to PVDF angle fitting) will flex, so the lid can be removed with ease by simply disconnecting the lid joint, flexing the pipette away slightly, and removing the lid..
That's it for now. I need a string of days off for the virgin run, because it will surely require a lot of monitoring and tweaking. The thought of being out of town while this thing runs (at least initially) is scary. Can't do it. The first run is definitely coming up very soon, probably in less than a week.
Thanks for following along so far. I'm having a lot of fun, and learning as I go. Hopefully all the hard work will pay off with mountains of useful oxidizers! 
3 Comments
Recommended Comments