Frozen Conduits

Status
Not open for further replies.

sparkyrick

Senior Member
Location
Appleton, Wi
I had to thaw some UG a few years ago. I attached a small hose to a fishtape and pushed them down to the ice. Then using a small fountain pump, I pumped hot water through the hose, the returning water was collected in a bucket, reheated with an immersion heater and pumped down to the ice again. I let this contraption run for awhile and advanced the fishtape every few minutes. I was able to melt through a LOT of ice and open the conduit.

IMAG0380.jpg

One more...

IMAG0381.jpg
 

sparkyrick

Senior Member
Location
Appleton, Wi
As you can see, I had to extend the conduit through the trough with some smurf and a PVC adapter to the bucket to make the recirculating concept work.
 

kwired

Electron manager
Location
NE Nebraska
Introduce a high current does not need to be ridiculously high but, likely needs to be at least 150 - 200% of conductor "normal" ampacity or it will seemingly take forever to thaw, on any installed conductors. Maybe plug ends of raceway as well to help hold in what heat is produced during the process.
 

tom baker

First Chief Moderator
Staff member
I had to thaw some UG a few years ago. I attached a small hose to a fishtape and pushed them down to the ice. Then using a small fountain pump, I pumped hot water through the hose, the returning water was collected in a bucket, reheated with an immersion heater and pumped down to the ice again. I let this contraption run for awhile and advanced the fishtape every few minutes. I was able to melt through a LOT of ice and open the conduit.

View attachment 12156

One more...

View attachment 12157

Very clever!
 

480sparky

Senior Member
Location
Iowegia
I buy a sackful of gas line anti freeze and pour a couple in the pipe, go drink a cup of coffee, come back and tug on the wires, repeat if necessary.

Please explain the thermodynamics that cause the anti-freeze to create the heat necessary to melt ice. Last time I sent to science class, anti-freeze could only prevent water from freezing (hence it's name), not thaw ice.
 
Please explain the thermodynamics that cause the anti-freeze to create the heat necessary to melt ice. Last time I sent to science class, anti-freeze could only prevent water from freezing (hence it's name), not thaw ice.

Kind of like putting rock salt or calcium chloride pellets on ice, I'd guess. That and the AF is likely to be warmer than the ice, which will melt some if it anyway and prevent it from refreezing. (z goes to look up the chemistry involved...)
 

ActionDave

Chief Moderator
Staff member
Location
Durango, CO, 10 h 20 min from the winged horses.
Occupation
Licensed Electrician
Please explain the thermodynamics that cause the anti-freeze to create the heat necessary to melt ice. Last time I sent to science class, anti-freeze could only prevent water from freezing (hence it's name), not thaw ice.
Kind of like Zbang say. It's not thermodynamics it's chemistry. Methonal and water want to be together more than horny teenagers so the methonal works its way into the ice.
 

480sparky

Senior Member
Location
Iowegia
So it works it's way into the ice. How does it create the heat needed to bring the ice above 32*F to melt it?

Sure, if the methanol is above 32, it will begin to melt it. But once it surrenders its heat and drops below 32, it quits melting the oce.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
So it works it's way into the ice. How does it create the heat needed to bring the ice above 32*F to melt it?

Sure, if the methanol is above 32, it will begin to melt it. But once it surrenders its heat and drops below 32, it quits melting the oce.
Let's say the freezing point of a 50-50 methanol/water mixture is 0F.
If you add an equal volume of methanol to a container with ice right at 32F you will not magically raise the temperature above 32F.
But you will start to dissolve ice in the methanol and cause the temperature to drop below 32.
Depending on the latent heat and heat capacity, you will either end up with all liquid at something above 0F or you will have a mixture of liquid and remaining ice at a temperature near or below 0F.
The analogy of adding salt to melt ice is perfect. Adding the salt does not heat the ice, it produces liquid/slush at a temperature below 32F.
 

Cow

Senior Member
Location
Eastern Oregon
Occupation
Electrician
Introduce a high current does not need to be ridiculously high but, likely needs to be at least 150 - 200% of conductor "normal" ampacity or it will seemingly take forever to thaw, on any installed conductors. Maybe plug ends of raceway as well to help hold in what heat is produced during the process.

I like this idea. Hopefully, I never have to use it though!
 

ActionDave

Chief Moderator
Staff member
Location
Durango, CO, 10 h 20 min from the winged horses.
Occupation
Licensed Electrician
So it works it's way into the ice. How does it create the heat needed to bring the ice above 32*F to melt it?

Sure, if the methanol is above 32, it will begin to melt it. But once it surrenders its heat and drops below 32, it quits melting the oce.
It's not the same thing as pouring hot water in.
There's no heat added or given up, there's a mixing of alcohol and water that has a lower freezing point.
 
Please explain the thermodynamics that cause the anti-freeze to create the heat necessary to melt ice. Last time I sent to science class, anti-freeze could only prevent water from freezing (hence it's name), not thaw ice.

The key is that temperature is the AVERAGE kinetic energy of something - some molecules are moving faster and some slower. Thus even below freezing, there are microscopic amounts of ice turning into water and back to ice all the time. The same phenomenon explains why water evaporates. So the salt or whatever sits there like a predator and once a bit of water appears it dissolves some of itself into the water and bam! it cant freeze anymore. Repeat. Kinda like a horror movie isnt it?
 

kwired

Electron manager
Location
NE Nebraska
So it works it's way into the ice. How does it create the heat needed to bring the ice above 32*F to melt it?

Sure, if the methanol is above 32, it will begin to melt it. But once it surrenders its heat and drops below 32, it quits melting the oce.
That is where the "repeat" portion of the process comes in - not enough was added to get the whole thing "thawed" continue below...

The key is that temperature is the AVERAGE kinetic energy of something - some molecules are moving faster and some slower. Thus even below freezing, there are microscopic amounts of ice turning into water and back to ice all the time. The same phenomenon explains why water evaporates. So the salt or whatever sits there like a predator and once a bit of water appears it dissolves some of itself into the water and bam! it cant freeze anymore. Repeat. Kinda like a horror movie isnt it?

You are not really "thawing" the (frozen) water, you are lowering the "freezing point.

Pure water freezing point is 32F (and I believe at sea level, or at similar atmosphere pressure typical at seal level).

Add any such component like we are talking about here to already frozen water and you will get some "thawing", but how much depends on many factors such as actual temperature, actual initial freezing point of the water before mixing, mass of water compared to mixed in "anti-freeze", pressure, and maybe some other things not mentioned.

If you only add enough to lower freezing point a couple degrees but actual temp is 20 degrees lower - you may get some local "thawing" for a little while until the "antifreeze" becomes more diluted in the water - but it will end up freezing again.


A good way to experiment some of these principals is to play around a little with your chilling mix when making homemade ice cream.
 

480sparky

Senior Member
Location
Iowegia
.....You are not really "thawing" the (frozen) water, you are lowering the "freezing point. ......


But the problem is... the water is already frozen. If you add enough anti-freeze that's above 32?F, yeah, you're adding enough thermal mass to thaw the ice. You could do the same with just about any liquid.... including plain tap water.

In order to physically thaw the water (ie, convert it from a solid to a liquid), you need to increase it's temperature.
 
Status
Not open for further replies.
Top