Posted on 12/23/2022 10:19:59 PM PST by Paul R.
Can supercooled running water freeze due to a pressure change?
Thursday I spent almost all day prepping for our "Arctic blast" that rolled in late in the afternoon. (Most impressive!) Among many other things, I checked to make sure the small thermostatically controlled heating element under our water tank was plugged in. (The wellhouse is part of but outside our house proper.) I ended up getting to sleep around 2 am -- exhausted & filthy I just crashed out on the carpet in the LR. (With all my warm clothes on it was quite comfy.)
I woke up ~8 am: Restroom!! Water (drip) running? Great! Outside temp on our back porch? -9 F, and still windy. Check the chicken house -- those birds may be dumb, but they are still all inside... Plenty of food still in feeders. I should be inside too and take my own advice...
Really should clean up! Fire up the in-wall heater in the bathroom (tends to get chilly in there overnight). Accelerate process by starting shower on "hot". Brush teeth. I'm almost done with the tooth brushing - water running @ sink too, total GPM probably ~ 2-2.5 gpm, and... the water slows and dies. What???!!!
Put dirty clothes back on, go investigate. Well pump gauge shows 38 lbs. pressure. (It kicks on around 35 psi or so. Pump has power. The pipes seem intact, but the electrical warming wrap feels cold - must have failed. The heating element under the tank is warm, but tank is still darn cool.
I get a small fan type space heater & set it up to blow warm air on the pipes. 10(?) minutes later, we have running water again, pipes are all ok. WHEW!
Take that shower / bath and warm my cold bones!
Best I can figure is that the water in the well (pressure) tank was nearly(?) supercooled and at ~45 psi (where it'd top out when refilling). Exiting the tank, the pipes would have been even colder, and there'd be some pressure decrease down the length of pipe (plus tank pressure was falling). Somehow, significant flow (as opposed to the drip) triggered an abrupt freeze-up. Could the pressure drop do that?
Yes, but, then the groundwater energy (plus a bit of heat from the pump) cools in the tank overnight and between pump runs. Apparently the resistance element fell behind — I do not recall a combination of wind and low temperatures like this since 2004, and, then we had a very heavy snow blanket to help insulate things. (Plus the heat tape, which is on about an 11’ run of pipe snaking around B4 it enters the house, failed this time.)
The resistance heating element under the tank, to be specific.
You are correct, this is the primary cause. I didn't think CO2 depressed the freezing point much, but it turns out club soda has a freezing point of -10C.
In one coop, I have a heater I built myself, using the steel housing from a gutted 4’ fluorescent light as a reflector, to which is mounted a small industrial quartz heater “block” (element). (The “block” is about .8” tall x 2.3” wide x 12” long with nice 1/4” threaded studs in the back.) The lead out wires are ceramic “beads” insulated. The element is rated at 230 or 240 volts usage: Run at 120v it barely glows, but still puts out a little over 300 watts, IIRC. I can switch in a series 15A diode (way overkill) to drop it to around 125 watts (measured current x rms voltage.) Even at 300+ watts it should last, well, a lot longer than I will! The weak point is probably the thermostat mounted on the side of the coop, but it should last a good while (rated for 1500 watts, is switching 300+ watts.) If I want to improve THAT, the thermostat can control a mercury wetted relay.
I “could” make up a variant of this for the wellhouse, as I have several elements left, and plenty of old / dead ballast fluorescent fixtures to cannibalize.
That’s fairly impressive!
I’ve even seen that effect using municipal water in ice cube trays. ;-)
This happened last evening to a bottle of wine my daughter brought over. She left it in the car for an hour and the cork popped!
The wine was like a slushy! But none of it spilled.
It was a very nice German Reissling.
Thanks to all the physicists and other scientists for all the explanations.
I thought alcohol couldn’t freeze.
But, then, I flunked High School Physics. 🙀
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