Compressed Nitrogen Application

Reckon you need to incorporate a heat exchanger to warm up the nitrogen. As Del says, the expansion as it comes from the cylinder will cool it (a lot!) - so you've got to lose some of the coldness (good physics, that!).

Next problem is - if it's used as a backup when your compressor goes off-line, there's a good chance you'll have lost your mains power, so you need something to get the heat from (i.e. to lose the cold to ).

Maybe a big tank of (?ambient temperature) water? Don't know where you're from, so no idea what "ambient temperature" is. You'd also have to do the sums for how much heat you needed to provide to warm up the gas, so you could work out the volume of your "cold sink" (AKA heat source) for the worst-case scenario. May have to keep the heat bath pre-heated while the power is on.

Just a thought ...

If you are pumping something, it is heating up at the exact time that you are expanding the nitrogen. Use the product being pumped to warm the nitrogen being used. I think the best benefit will be to use the heat exchanger just before the nitrogen enters the pump.

Try putting a multiple stage orifice in line with the nitrogen bottle to take many small pressure drops before the air motor regulator instead of one big one.

Contact your compressed gas provider they have several gases that you can use instead of using antifreeze and dealing with the polluation problems related to that.

what is use of air for pmup operation?and also specify at which condition is operating means tempature, pressure.i may be help u if you tell me more about the operation and operating condition deatails.

pankaj

Google the Joule-Thompson expansion effect, and see what happens.

Hello,

We did a similar attempt when liquid CO2 was obstructing our expected system success.

We introduced a CO2 absorber/converter in the system and Problem Solved.

From that logic, compressed Nirogen converting in to Nitrates must be giving you the process difficulties. To avoid Nitrate Formation or dissolving thereof, I suggest you Place a Small Dose of Nano CATALYST, new discovery by one of the inventors, we know, which is non perishable and effective to Handle Nitrates.

Catalyst Cost is INR 10000 for a small dose of 100mg good for one CuM. I am open to arrange supply and call back at 50% cost refund if it fails to meet your needs. Same Catalyst could be used to remove Nitrates from Waste Water say Sewage waste Water Or Drinking water infested with dissolved Nitrates making it non potable.

This is only a thought and you may advise the Dimmensions of your Holding of Nitrogen in flow to suggest a sutable Insert of Catalyst in Device form.

Pl. get back to me on kishorekaikini@gmail.com kishorekaikini@yahoo.co.in

Best Of Luck;

Kishore

<...compressed Nirogen converting in to Nitrates must be giving you the process difficulties. To avoid Nitrate Formation or dissolving thereof...>

This is incorrect. No chemical changes are taking place in this system. All the changes are due to the physical properties of nitrogen at different temperatures and pressures, which are similar to the properties of air.

The reason the nitrogen becomes cold is that it cools on expansion due to Joules Thompson effect. Helium and hydrogen warm when expanded at room temperature, but helium is too expensive and hydrogen is too dangerous to use in your application.

There are only three solutions to this problem that do not call for adding something to the gas stream: reduce the nitrogen pressure in the backup supply storage tank to the point that the cooling does not cause freeze up, or warm the nitrogen before it is expanded, or some of both. In the first case the nitrogen will still cool, but not enough to freeze the air motor.

You need some type of heat exhanger or gas warmer between the regulator and the pump. I have seen finned tubes installed on large compressed gas tank delivery lines that are only exposed to ambient temperature. These may form ice on the fins, but the gas is sufficiently warmed for plant use.

Ask your gas supplier for a source of these heat exchangers.

Google "ambient air vaporizers" and you should get around 9,000 posts similar to this product.

http://www.chart-ind.com/litfiles/11640222.pdf

Install between the regulator and the pump. Best of all, it has no moving parts and after purchase and installation will use no energy.

PV=NRT, Work up the temp drop for your self. Simple.

I have also seen this problem with both pipeline and vaporized nitrogen (and compressed dry air) on the discharge of air diaphragm pumps. In our case the expanding nitrogen left the exhaust ports very cold. The N2 was very dry. Lots of ice accumulates on the exhaust port and restricts the flow. We concluded that the moisture in the ambient air was condensing and freezing on the very cold parts. The first solution was a vendor supplied antifreeze that is aspirated to the inlet gas supply. That gets expensive.

We evaluated warning the incoming gas, it was not cost effective. The ultimate solution was to run the exhaust gas through a pipe and larger "muffler" away from the pump discharge. The Exhaust area was increased to a very large pipe that could warm up as it is exhausted reducing the temperature drop. Freezing sometimes continued but away from the mechanical plenum and pump parts.