With a little time yet before I need to start testing the large cryocooler, I needed to catch up on the leveling that Zaka, Zeb, and I agreed to. Ultimately, I decided to not only do the couple of days of catch up, instead I did training until the start of the new year. It was a good break while I contemplated how I could handle the next few stages of work. No matter how many days I work on leveling though, it always feels like I've barely moved the needle anymore, which is too bad. It's even worse relying on fishing. At least on the other island, the large lizards still make a dent.
Level: 69
HP: 3439/3439
MP: 1838/1838
Traits: Mana Affinity, Earth Manipulation, Improved Dexterity, Heat Resistance, Partial Sleep
Magic: Improved Stone Shaping, Tectonic Sense, Improved Earth Spike, Thermal Hands, Pulverize
I did come up an idea to improve how I'm doing testing while I was levelling. For one, while the ethanol thermometers do freeze before they're directly useful, I could cool a metal object down and submerge that in a consistent quantity and temperature of water, and measure the resultant water temperature. That will at least let me compare trial runs to see how cold things are getting in each run. Thanks to thermal hands, I shouldn't have much of an issue with getting the initial temperature set for the water either.
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I had a copper ball made that was three inches in diameter, and I had some larger dewar flasks made, which could fit the new cold-side piston head through their opening. That took a few days of the start of spring to do, along with getting extra testing components made, but the reservoir does still need to build up some more volume before it'll be useful, so I didn't actually waste any testing time. I'm also fairly confident in my choice of lead wool for the regenerator, so that's at least one component of this larger cryocooler that I won't need to test.
I had hoped that I'd be able to do two tests a day with the larger cryocooler by using the metal ball for thermal tests, but I actually have a different limiting factor. I can only produce enough dry hydrogen to charge the larger cooler's internals with once a day, so I'm still limited in my available tests.
I have four main components I want to do testing on, the hot-side heat exchanger, the hot-side piston, the regenerator, and the cold-side piston. Unlike the previous tests with the smaller cryocooler, replacing each of those components is actually a decent chunk of labor from me and the blacksmiths. Each component likely has some degree of effect on the other component's sizing as well, so changing any one will affect the other's performances, making the testing somewhat difficult.
So I've made only two versions of each component for now, designed in the way that I suspect they might perform better. I have sixteen tests planned, using each of the possible combinations of components. From that, I'll try to get better insight into how the components interact at this larger size, and then make another set of components, and repeat the testing cycles through spring.
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The first round of tests were very disappointing. In fact, none of them froze the ethanol thermometer. However, I did get insight into what direction to go for the next set of components. I kept the best combination of the testing components, and then made new components that were more exaggerated in the direction they were going. The hot-side piston became wider with a shorter travel distance, the hot-side heat exchanger tubes became slightly larger with fewer tubes in total, the regenerator became longer and thinner, as did the cold-side cooling piston.
The new components for testing took another five days to make, followed by another sixteen days of testing. After the second round of tests, two of the sixteen tests were able to freeze the ethanol thermometer, and required using the copper ball to start estimating their performance against each other.
It took three more rounds of this style of testing before I started to zero in on the best designs for the components in this configuration, which brought us out of spring and into early summer. I wasn't done yet though. Some of those configurations had started to produce liquid air, but I had only hit near the target. Each of the tests prior to this had involved fairly large step changes in component designs.
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I resigned myself to using all the available dam time this year for testing, and then moving on to working on the separations column next year. I did five more rounds of refining of the design before the reservoir was depleted beyond the point of being able to drive the piston. The last two rounds were very marginal in their improvements as well, so I'm quite content with how this cryocooler works. In fact, the building itself was very chilly despite the season by the end of everything.
The final yield of the large cryocooler came out to be about a third of a gallon. Which might not seem like much, but considering where we are technologically, it actually is quite impressive, I think.
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In the year or so I've worked on this project, I've basically neglected a ton of other projects that were ongoing, so I took the time to examine those in greater detail before I returned to start designing the batch separation column.
First, I checked in on how all the mining was going. The tunnel progress had slowed somewhat as more resources were diverted to looking for mana crystals. They have found some, but the crystals are fairly small, and the deposits are far fewer in number than they were around the cave. They're still expanding out to find more pockets within the layer, but the yields have been abysmal. Though having some crystals are better than having no crystals. They've set up a small storage room just before the crystal bearing layer, and have filled a handful of small crates with mana crystals, so we do have something.
One of the dwarves seems to have gained enough levels that they've gained access to their linear rock scouting ability that Konkur showed me. So they're basically digging tunnels from one pocket to the next, guided by his ability. I let them know that if they run out of pockets, they should just resume digging the tunnel forward, and not to stress over continuing to find mana crystals here.
The next thing I check in on was how all the experiments with Tiberius went between refrigeration and mana isolation. For the most part, things went quite well, and he's developed quite a list of results. While there doesn't seem to be an easy way to determine in advance what storage method will work best for a particular extract, they basically all fall into one of three categories.
The first are extracts that survive being frozen, and are indifferent to being isolated from mana or not. Only a single extract, the fish which throws its spines, seems to fall into this category, but it's conceivable that others will as well. The second type are those that survive being frozen, but do need mana isolation as well. About half of the extracts fall in this category, and seem to basically last indefinitely when frozen. They all experience some amount of effectiveness loss, but that seems to come from defrosting them, as they lose the same amount of effectiveness whether they were thawed either a day or a year later.
The final type are those that benefit from being cold and mana isolated, but break down once frozen. The remaining half fall into this category, including the mana poison type extract from the mountain plants. Unfortunately, everything in this category also seems to break down somewhat quickly, even when refrigerated. The longest lasting extracts lost about a quarter of their potency over the year. The mana poison plants lost about two-thirds of their effectiveness over the same period while being refrigerated. Making refrigeration of the mana poison practically pointless.
We also had the secondary experiment going with cut quartz, which yielded the results in line with what I expected. The larger cut quartz blocks performed better in isolating internal materials from the same thickness of the smaller quartz blocks, but both seemed to perform better than the randomly packed natural crystals. My guess is that the naturally packed crystals still have too many air gaps, so while they provide a decent chunk of isolation, it's not nearly as much as tightly packed crystal blocks.
With those results, I went to the quartz cutting area, and spent ten days adding in some new production lines. First, I added an even larger size block. While very few of those blocks will ever be made, having the option in the future to use them will probably be valuable. Second, for all three lines, I also added a function to the block cutters. The ability to make half blocks in both height and length. I don't want many of those made, but if we have multiple layers of cut quartz, staggering the spaces between them by using half blocks will probably improve the mana isolation efficiency somewhat, and even if it doesn't, it'll improve the resilience a wall made that way against physical collapse.