I tested different figurations o a time for a day each, with a day of dowo adjust the build iween each test. By the third test, I decided to make a sed stirling cryocooler for testing, so I wouldn't have to take a day of dowo make modifications. By the fifth test's pletion, I had the sed cryocooler to work with. I then decided to make a third one, and run two tests in parallel at a time, since I still had quite a bit of free time while the tests were running.

  After fifteen days, I had three cryocooler tests running at a time, with one down for ges at a time. With three cryocoolers, I was also finding myself having to spend some time each day ht produg the dry hydrogen to recharge the stirling system with, since each time I ged a po, I'd lose the gas during maintenanbsp; Unfortunately by this point, I still hadn't achieved any success with liquifying air across the ten differe runs, and without a thermometer that could reach that low, I really didn't know how effective I was being. I did get some test results that at least led me to some preliminary clusions oter.

  My testing began with three different sizes of steel wool packed into three different sizes eors. None of which yielded any liquid air. I moved on to the prepared metal wool, copper, which again across the ests, didn't produy liquid air. I got the same results for zind lead as well after a total of 36 tests over. However, the copper tests were uo freeze the thermometer in all but o, and zinc shared a simir fate in three tests.

  In the copper wool tests, the only ohat did still freeze the thermometer was the rger regeor with the smallest wool size. In the zinc wool tests, the smallest regeor failed with the rgest and medium sized wool, and the middle size regeor failed with the rgest wool.

  That information, while not perfect, indicates that higher thermal ductivity in the regeor material is a problem, and that the regeht still be undersized. It also seems to indicate that I want higher surface area. As much as I'd like to just use metal shavings to drastically increase surface area, I don't have a good way to keep them in p the regeor, so I'm stuck with metal wools instead.

  Thankfully, lead seems to work well, which means it is in petition with steel wool. Lead is quite soft, which should make it much easier to make a finer grain wool to use as well. So, I've decided that the stages of testing will only involve steel and lead wools alongside new regeor sizes.

  The ests were actually quite iing. The ests included the previous fi metal wools, and two new finer grains, along with rger regeors. With our dies, this is probably the fi steel wool we make, but I think we still make even finer wool from lead. Ultimately, this round of testing was 18 trials long, with three regeors and three wool sizes for the two metals. The rgest of the new regeors packed with the fi wools of both steel and lead also failed to freeze ethanol, however, the rger grained wools still worked in that regeor.

  My hypothesis is that as the wool gets finer grained, it has a higher resistao airflow, causing losses. Despite the fact the rgest regeor with the smaller wools failed, the smallest of the new set eors with the fi grained lead wool produced a miniscule amount of liquid air in the 24 hour period. Or at least, I assume it was liquid air based on it's behavior. That meant to me that I otentially on the right track.

  With that result under my belt, I decided to focus in on improving the lead wool and regeor design in the set of trials. I'll try to push the limit of how fine we make the lead wool to see how effective we make things.

  After a week of testing, we were able to make aremely fine grained lead wool by briefly heating the wire just before pulling it through the die and then catg the shaved pie a pte to prevent the lead's weight from tearing the shaving. It was very bor inteo make this ultra-fine grained wool, but it turned out to be worth it.

  Since I believed we had somewhat dialed in on the correct property of the regeor material, I only used two sizes of lead wools in the ests, though I did use eight different regeor sizes. The third smallest of these regeors loaded with the fi of the wools produced the most liquid air, followed by the sed smallest regeor for total volume produced. So, I made an intermediate size between those two, and found that this intermediate was the new highest producer. I repeated that process of making intermediate sizes two more times before I settled on what I believed to be a fairly optimal size regeor.

  As for the amount of liquid air produced in a 24 hour period, we were still only looking at about a fluid ounbsp; There was a sedary problem that likely reduced the amount produced, however. That problem was buildup of id solid CO2. So I took a few days modifying the building where the crycoolers were housed. The room now has desits inside as well as in the newly installed air vents, to help reduce the total volume of water in the room. I watched the new produ over it's 24 hour period, and periodically scraped off id CO2 that built up, and ultimately, this cryocooler design produced about 3 ounces of liquefied air.

  When we move ter produ, we'll likely o have workers manually scrape material from the cold denser piston occasionally as well. Though, since I have these smaller cryocoolers, I do sort of want to put them to good use in the final facility by installing them in the air intake lio the facility after the desit, to potentially de some of the CO2 before hand while also pre-cooling the air into the facility. It won't be much cooling, but I'd hope that some is better than none.

  With that, I'm fairly fident that I should move on to the rger cryocooler designing stage now. It will also need a signifit amount of testing done, and winter is only a month and a half away. I want to make sure that by spring, I'm ready to do testing.

  The first issue I had with the rger design was that I needed a plete redesign of the hot side heat exger. Because the whole design was much rger than before, I needed a proper heat exger with small tubes to effectively transfer heat from the internal gas to the copper piping I was using. Since I was using small copper pipe, that also increased resistance, meaning I needed more powerful pistons to drive the exger. Due to the size of the whole device, I then o add a pump to a water reservoir that could run water over the heat exger, and the whole desig growing and growing in size. It grew to the point that the only way to properly drive this cryocooler would be to use the dam, as it would be the only thing providing enough sheer horsepower to turn the whole thing.

  I'm thankful that I decided on a batch process, so that downtime happen each year to repair the engine as needed. The copper piping will probably o be repced at least once a year, and new grease will o be applied regurly as well. Hydrogen will o be recharged frequently, and the regeor's internal material will o be repced on occasion to keep efficies high.

  I ended up spending quite a bit of time building the housing facility for the cryocooler. It's a facility built onto the base of the dam, simir to the hydroelectric facility. The main spillway is situated between this facility and the hydroelectrie, meaning I really don't have any more space for facilities powered by this dam if I need one in a future. The hydroelectric facility does at least have extra spaeors and maes though.

  This facility could potentially house a sed rge stirling cryocooler iure, and has space for the eventual distiltion n. The facility has thick, triple yer walls with an air gap between each wall. The way in and out is through two sets of doors, where ideally only o of doors is ope a time to reduce air leakage.

  There are four moderately sized vents to provide airflow into and out of the building, each of which has desit trays, that easily be removed and regeed as needed. On the ihey each also house a box with a stirling cryocooler cold side denser io pre-cool the air being drawn into the facility. A main kshaft from the dam will then power those four smaller coolers, while the rger stirling cryocooler will have it's own power source.

  Ultimately, all the stru and design took until the st month of the year to plete. Even with all that, I still o do testing and resizing of pos on the rge cryocooler to try to optimize it's produ of liquefied air ohe spring rains refill the reservoir.