Why Don't We Melt Snow?

I understand that Peter Jackson faced a similar problem with TTT. Frodo, Sam, and Gollum walking by a stream on a warm spring day. And Gollum wriggling his way after a fish in the stream.

Andy Sirkis deserves an Oscar for even trying that.

You can still get those:

Granted, it’s from Harbor Freight, so it just as likely may burn your face off as melt any ice.

I don’t think you kids are getting the whole idea.

Ducati’s Clean & Clear Snow Removal Unit (patent pending) would drive down the street, pulling snow in like a snowblower. The snow is fed to a hopper that’s already boiling or hot. Propane or CNG heats the water to steam, which is exhausted into the air. We’re not putting water back on the street to freeze. Then the jet exhaust (or whatever 300 to 500 degree air we can make) is blown down to heat & evaporate any remaining ice & moisture left behind.

Or perhaps two jets…
One to blow the road dry and one pointed up; feed the snow into the exhaust stream and it will be evaporated immediately. No hopper needed. This is a work in progress…

It wasn’t my idea to dump snow in the river. It’s theseguys. **My **idea avoids that.
Try paying attention.

And right-now travel is pretty important. Look at the billions in revenue lost from employees not getting to work, the danger in doctors, nurses, etc. not making it to the hospital for days on end, firefighters & paramedics stranded. How about all the cancelled flights when they shut down ORD, JFK, LGA, BOS and more?

A big snowstorm like the NE has this week is costing each state billions of dollars.
I’m thinking a system that gets traffic flowing quicker has some value…

You kids want to get in on the ground floor here, I’ll consider taking on some investors! :smiley:

I don’t think you are getting the whole energy cost of what you are proposing, nor the scale of the problem. It’s much cheaper for the people who need to travel to buy snow tires and 4WD, and for everyone else to stay home.

But you can’t really avoid putting the water back onto the street to freeze.
After you exhaust the steam into the air, it’s going to cool. Eventually it will cool down to the dew point, upon which it will then condense onto stuff (typically the ground or street). Now you’ve got ice. Maybe not right where you removed it from, but somewhere downwind of where you’re exhausting it.

HUGE energy input required. HUGE costs. WAY more expensive than the present day alternatives. Impossible? No. Too expensive? Yes.

Yeah. You know that whole equal and opposite reaction thing? It’s kinda the same concept here. For every degree that the boiler system brings into the mix to elevate the snow to water to steam, you have an equal fight on the other side of snow trying to lower the temperature of the boiler system. With a constant influx of new snow into the system, you’re going to require constant energy to keep that heat up to the level you want. Energy = gas = money.

Here’s a small scale example of this.
Get a pot of water and put it on a burner. You see how much energy it takes to bring that pot of water to a boil? Now is it nice and boiling? OK, drop an ice cube in it and watch the whole system collapse below boiling while it takes care of the ice cube and tries to push back up to boiling again.

Or skip the water. Get that pot really good and hot. Now throw in an ice cube and watch it sputter and splatter as it instantly turns to water and then boils.
Now throw in an entire bucket of ice cubes. Probably half of them will melt instantly and start boiling but the other half, even inside a pot that was really hot a moment ago, will just sit there as ice until the pot’s hot enough again to melt it.

Why don’t we just dump the snow into volcanoes?

Oi, now you’re suggesting we take it through another phase change? The energy costs just went through the roof, there. It already takes a pretty hefty amount of energy to get from solid below freezing temperature, to solid at freezing temperature, then significantly more than that to get from solid at freezing temperature to liquid at freezing temperature. But now you also want to add enough more energy to get it from freezing temperature to boiling temperature, and then you also want to go through the incredibly energy-hungry liquid-to-gas phase transition, too? You’d need more gasoline than the amount of snow you’re clearing.

Oh, and from the OP:

Considering, nothing. Every single northern city that has a major waterway already does this.

Even if you do not directly dump the snow in the water, the runoff when it melts will go there via storm trains in most cities with surface water. Here in Minneapolis, they have painted signs near some of the drains that indicate which body of water they are connected to, so people are discouraged from dumping paint and other waste down them.

I don’t understand these machines. Cities already load dump trucks up with snow to move it place to place, so why don’t they just bring the loads of snow inside? Surely there are garages to store public works machinery. The building would be far cheaper to heat than to buy and run a snow melter, and once the ice melts, you have water 1/12th the volume of the snow to deal with. But as far as I know, no one melts snow in the way I suggest.

The Russians don’t mess around when it comes to snow and ice removal:

http://www.automotto.org/entry/in-russia-jet-engines-go-to-work-as-snow-blowers/

Are you aware that it uses the same amount of heat to raise 1 unit of water 1 degree, whether it is “inside,” “outside,” or in a pot, aren’t you?

Exceptions…caves (and volcanoes), where you aren’t paying for fuel to provide heat.

In other words, you’d be paying to melt the snow via the fuel spent in heating the building, versus the fuel spent in running the snow melting machine. You can’t cheat the laws of thermodynamics. If you ask, “but the building’s already warm, how does it cost more?”, the answer is that, in the process of melting the snow brought into the building, the interior of the building itself will cool down, and will need to be heated back up by the furnace (or whatever is being used to heat the building).

Hell, let’s do the math. One mile of residential street, 25 feet wide, with an inch of snow on it, will have about 300 cubic meters of snow on it. If snow is about one-tenth as dense as water, then its density is about 100 kg per cubic metre. So you’ve got about 30 metric tons of frozen water on the street. Melting this amount of water requires about 10 billion joules; heating it to 100°C requires 13 billion joules; and turning it to steam requires another 70 billion. The energy content of a U.S. gallon of gasoline is approximately 130 million joules, so we’re talking a grand total of 80 gallons of gasoline to melt all that snow, 100 gallons to warm it to boiling, and and another 500 gallons (!) or so to turn it into steam.

So the grand total for your plan requires the energy equivalent of almost 700 gallons of gasoline — multiplied by the number of miles of streets you have and the number of inches of snow that have fallen. (Remember, the calculation above assumed one mile of road with one inch of snow on it.) If, as recently happened, Chicago got a foot of snow, you’d need nearly half a billion gallons of gasoline (or energy equivalent) to melt all the snow. At that rate, it’d probably be more energy-efficient to give everyone in the USA a four-wheel drive SUV and not bother plowing the streets at all.

Actually the EPA has made it illegal to just plow snowbanks into a body of water …

Which made it absolutely hysterical in the Portsmouth Naval Shipyard when mrAru was duty stationed there. They could not plow the roads off the edge into the river, but they could plow the snow into a drydock and open the gates to let the water in to melt the snow … :confused::dubious::rolleyes::smack::smiley:

Honestly, those morons decided that ‘the snow would melt and dillute the brackish water’ despite the snow would naturally melt and run off into the river if left alone piled up on the ground by the river, or plowed into the drydock and flushed … so WTF.

On the plus side, though, this did give me a good problem to assign on the next homework in my thermodynamics class. So some good came out of it.

Because all you’d have is a building full of snow and dump trucks full of snow lined up outside with no place to put it. The energy cost and logistics are well beyond what you are thinking. The building would basically have to be a power plant doing nothing but melting snow, and it still probably couldn’t keep up.

As mentioned below, not any more they don’t.

In addition to the amount of energy needed to melt the snow, the other problem is that there isn’t enough room in the public works garages to store all of those dump trucks indoors.