biodzldan

Typically, the more you increase the frequency, the quieter it will become. This is for a few reasons: you're hopefully well above the resonant frequencies of anything you're attached to and therefore not exciting them, as well as moving most of the noise above the range where human hearing is most sensitive (2-5kHz). This comes at the cost of lower efficiency - most of the losses in the silicon occur during the switching as opposed to the 'ON' state. If your motor is rated for use with a VFD, I don't think you will experience much trouble by raising the frequency. The voltage transients and internal heating effects should *hopefully* have been anticipated by the manufacturer. I just had to deal with a similar problem on a machine that my company manufactures.

Jon, I live in Vine. We've met before, briefly, and have several mutual friends. The building I'm looking at is about a mile away from you, if the inspectors are in favor of me having an H-3 occupancy there. They've been hard to pin down. Incidentally, I think I managed to point out to them that you guys didn't need an ASME stamp for your still because B31 doesn't kick in until 15 psig (they were hinting they wanted me to get stamps too and I argued). Although obviously that doesn't help you much now. If you end up running any small test batches, something like a sugar wash will give you an indication of whether infection or enzymes are at play.

Jon, Kalamazoo uses gaseous chlorine year-round, meaning simple aeration should allow it to dissipate. The concentration varies throughout the year - more in the summer when the water tower is warm (although to me, it didn't smell like it got as high as other years, possibly because we had a cool summer). The point that Silk City made is worth paying attention to. There is construction near you right now that I believe involves water mains. A quick phone call might prove helpful. Personally, I would not continue to waste resources attempting production-size fermentations unless you're absolutely starved for output. I would consider running a series of experiments in the range of 5 gallons or less. I would say the first question you want to answer is whether an infection is present or not. A microscope and some stain should give you an idea fairly quickly. I think I know a couple people in town that may have something appropriate if you don't have one (I was waiting to purchase one until early next year). If there is an infection, you can start working backward to the cause. Aerate some water to dissipate gaseous chlorine, carbon filter some to remove chlorine, maybe get 5-gallons of RO water from the co-op, you get the idea. If you do all of those with careful attention attention to avoiding an infection, and none of them become infected, they may indicate something in your building.

Have you tried plating it to see if you have anything else growing, or checked cell density?

I had the impression that the problem with keeping a mostly-empty bottle around was not so much with oxidation, but the fact that so much aroma is lost to the headspace.

Agreed.

At best, they could make GNS. Where the heck is it all going to go?

Read through the CFR referenced above and realized that the TTB won't care about how I weigh my fermenters, since that is not where I'm calculating tax. In that application, you frequently have the opportunity to re-zero. It's also helpful that what I really care about is differential weight and not absolute weight, and being within 1-2% of absolute is sufficient. For permanent connections to tanks, you just try use flexible, horizontal connections where possible to reduce reaction forces. I doubt they would account for more than 1% of the total load in my my application.

Do they not allow the tank and load cells to be calibrated as a system? For large tanks and hoppers it is not uncommon to measure an amount of material on a smaller, calibrated scale (say, a tote in our case), and then pump that liquid into the tank being calibrated. Repeat several times. As long as you start with sufficiently accurate calibration weights and are mindful of things like creep, you can maintain a good level of accuracy in the final system. It has the advantage of taking into account reactions forces and deflection that you weren't able to fully prevent. This is how I am planning to calibrate my fermenters.

As a general rule, never distill until dryness. I know it's not likely, but if you had tried that with ether, your equipment might have exploded. It's one of those things like adding acid to water. Do it every time. I referenced the TTB videos as the standard technique I use for experiments.

That's a clever way to safely make a pressurized system. However, I will have pressures ranging from 7psia-15psia, depending on the part of the system so it probably isn't a great fit for my application. My water columns would be clumsily tall and I would run the risk of back siphoning during process upsets and startup conditions.

I am considering that as an option as well. The cost per piece will be a big factor. I will not be using a conventional pot still or kettle. The design I am using will require about a dozen pressure relief points. My main reason for not using rupture disks is the one-time use. During software tuning, I could accidentally overpressure several times. It's not that I am seriously worried about my safety while doing this, the components are more than capable of handling the pressures, but I am planning to stay below 15 psig in operation to avoid ASME B31 compliance and let my building and plumbing inspectors rest easy.

Ok, I had looked at a few other sources for stainless ones, but I'll see what you find. Personally, I am comfortable with a brass valve, knowing that I can locate it properly. My bigger fear was whether an inspector would have a problem with it.

I was specifically referring to the relief valve in isolation, not to any particular still design. Meaning, if the valve was placed in a location where it could lead to condensate collection, I was wondering if it could be a problem.

I was specifically referring to the pressure relief valve. The only risk I could foresee is if there was a drip path that allowed it to drain to the condensate collection.