Adapting my previous designs for the large and small cryocoolers to be made in the new stirling facility took eighteen days. Then, while I had the goblins making the cryocoolers and stirling engines to power them, I started building the new facility. I started with the underground part of the facility, since it would also provide me with the stone to build the above ground portion of the facility. I decided that ultimately, I want a five foot thick roof on the underground portion, along with a few small vents to let extra air out from any evaporating materials.
After taking nearly thirty days, I'd excavated the underground portion and had finished work on the dewar style tanks for storing the cryogenic fluids. Each tank is equipped with two outlet valves, a pressure relief valve, a small cryocooler to keep the contents liquefied and an emergency failure patch of thinner material that should fail before the rest of the tank. The underground room also vents to atmosphere in case of an accidental spill or a more catastrophic failure.
The first tank was a ten foot in diameter by twenty feet long monster of a tank that I embedded partially in one wall. If the atmosphere is something like 75% nitrogen, then this tank should take about four years to fill up with liquid nitrogen. The second tank was eight feet in diameter and ten feet long. Using the same heuristic pattern, this one should hold about four years worth of liquid oxygen. The third tank was four feet tall and three feet in diameter, and should hold four years of argon.
I also installed two more tanks that were identical in size to the argon tank. One is for holding liquid air before it goes into distillation, and the other is for holding the argon rich oxygen portions until they can go into a separate distillation column. I haven't started on the columns yet, but I've decided on making two fifty gallon columns, and two ten gallon columns. The larger columns are for separating liquid air, while the smaller ones are for processing the argon. Since we're doing batches, I want to have two columns for each, so that we would have redundancy during maintenance times.
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Unfortunately, designing the columns actually requires that we have access to liquefied air so that I can do the necessary tests to determine column efficiency. However, I did learn quite a bit from the last column design, so I could get most of the columns' components built before I actually started fine tuning. All in all, after twenty-four days I'd finished getting the columns mostly assembled and the casting teams had made all the large cryocoolers. Well, they'd made the shells. I still needed to take the time to charge them with hydrogen.
So, next, using the stone from excavating the underground portion, I first rebuilt the roof over top the pit where I'd been working, to make a basement. I then installed some of our fluorite crystal lights on the ceiling in the basement to keep things visible. Then, over the course of another twenty-six days I had the surface building built. Once again, I went with a double layered design, meant to help keep the inside of the building more insulated. Ultimately, I designed it to be a long hallway with fifteen cryocoolers on either side. Their hot ends extend out of the hallway and are exposed straight to air for now.
At the other facility, they have flowing water to cool their hot end's down enough to allow cryogenic temperatures. Here, I've gone with a slightly different approach, and we'll see if it will work. The hot ends have very large copper heatsinks installed on them with a fan blowing air rapidly over each individual heatsink's surface. The fans are angled upwards toward the sky to hopefully direct the heat up and away from any air intake. The issue with attempting this before would have been the amount of mechanical power necessary to actually power an active cooling system in addition to the cryocoolers. Now, with the fluorite powered stirling engines, I'm less concerned with not having enough power.
I've gone through a lot of trouble to attempt to design this place to ensure that the air inlets into the cryogenic building are isolated from all the rejected heat that we're producing. Along the roof of the facility is where the five largest stirling engines will sit to power the cryocoolers. At the far end of the building, there will sit two more engines of the second largest size, each driving the fans for the heat sinks on their respective side of the building. The air intakes into the building go through desiccant, and then their own moderately sized freezer chamber designed to freeze any remaining water, and potentially some of the CO2, out of the air before it reaches the main room. Each of those freezer chambers also has it's own stirling engine power source, though it's being mechanically powered through a long axle to keep the engine further away from the air inlets.
A case of literary theft: this tale is not rightfully on Amazon; if you see it, report the violation.
Ultimately, it's very similar to the other cryogenics facility, however, due to the size of it, many items were scaled up. I have about twenty days worth of changes and adjustments to make before I actually start turning things on by fetching the crystal plates to plug in to the bottoms of the main stirling engines.
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The first thing I needed to do was generate enough hydrogen to charge the cryocoolers. The hydrogen facility seemed to work, at least for the time being. I didn't need that much hydrogen either, so perhaps in the future if it runs for a very long period of time, it might end up showing signs that I need to make changes. Ultimately, I brought the hydrogen generating plates up from storage down in the crystal facility for a few days to make the hydrogen I needed, then put them back down there. If the hydrogen plant starts running full time in the future, I'll want to keep an eye on it for a bit to see if I notice any dangerous defects occurring.
After the cryocoolers were charged, I went through a manual check of all the connections and devices to make sure that nothing was experiencing any sort of mechanical issues that would potentially cause mechanical failures that would require rebuilding things. Once everything seemed to be good, I was two days ahead of my estimate, and so I tried to turn the facility on by installing the fluorite heat crystals.
At first, everything seemed to be working as I expected, which had me feeling quite good. However, as I brought more crystals up, and started turning on more of the cryocoolers, I started to notice an issue. With each new power stirling engine I turned on by bringing up a new crystal, the more all of them seemed to struggle. By the time the last engine was turned on, I could tell that they were all struggling to actually power the number of devices they were attached to.
If I hadn't already designed the air system going down to the crystal growing area, I'd probably be more stumped on what was happening. Today, however, there is almost no wind, and while I know that mana can flow against the direction of airflow, I know that it more readily flows with the direction of airflow. We've got a total of six massive stirling engines powered by our largest crystal plates, and four of the next largest size, all concentrated within this one area.
So, I did a small test, and sure enough, my mana regen on the roof of the building was about half of that just over fifty feet away where it was normal. So, first I shut down all the engines so that they wouldn't degrade, and moved their heat crystals back underground to preserve them. Then, I got to work on what I hoped would be a working solution.
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If mana flow is helped by airflow, then it's somewhat reasonable that we just need a bigger natural airflow over these engines. On a windy day, they might run fine on their own, but I don't want to wait for a windy day. So instead, on either end of the roof of the long, hallway like building, I installed two massive fans pointed from the front to the back. Each fan has a ten foot radius with six blades, and it rotates about 10 times per second.
Building them took six additional days of time, and I used a single of the second largest stirling engines to power both of them. There was a significant amount of airflow over the roof now. I then took a day getting all the stirling engines turned back on. This time, only the very last engine seemed to be struggling a small amount to keep up, while the first engine was actually working overtime.
I could already envision a much better system, using individualized air intakes that would flow directly over closed cavities over top the crystals for each stirling engine, but implementing them would take additional weeks of time. Instead, I took an extra two days, and installed two smaller fans angled in on that side of the building pointed at the last engine, and that seemed to do the trick.
Thankfully, it's the middle of winter now, meaning I can easily go and move the goblins who worked at the old facility, and bring them to work at this one. I'll need more intermediate dewar flasks for transporting and collecting all the cryogenic fluid we'll be making while I fine tune the new distillation columns. So for now, I'll shut the facility down again for a few days while I get the goblins up to speed.