Steam Fire and Jet Blast

How do you propose to start the ram jet?

I can not see how that would be a problem? I have never started one, but others sure have.

I would think it would probably before adding water to the apparatus.

Is there something you are aware of that may seem like a problem?

Thanks for your interest.

To quote Wikipedia:

"A ramjet, sometimes referred to as a stovepipe jet, or an athodyd, is a form of jet engine using the engine's forward motion to compress incoming air, without a rotary compressor. Ramjets cannot produce thrust at zero airspeed and thus cannot move an aircraft from a standstill.

Ramjets require considerable forward speed to operate well, and as a class work most efficiently at speeds around Mach 3."

To quote Wikipedia:

"A ramjet, sometimes referred to as a stovepipe jet, or an athodyd, is a form of jet engine using the engine's forward motion to compress incoming air, without a rotary compressor. Ramjets cannot produce thrust at zero airspeed and thus cannot move an aircraft from a standstill.

Ramjets require considerable forward speed to operate well, and as a class work most efficiently at speeds around Mach 3."

He clearly is referring only to a pulsejet, which can operate - albeit not very efficiently - under static conditions. He seems to think that ramjets are the same thing, but of course that's not so.

I'm assuming this will be a valved design, because he wants to use it to drive a secondary flow and a valveless design won't tolerate much backpressure.

One thing you might consider, that blast you are referring to may spread the fire worse. I have seen a CO2 fire extinguisher hit a dust pile and actually make a dust explosion in an open field. Of course all tools do become weapons in the wrong hands.

The steam might not be a good thing either, range would be limited and it would tend to drift with changing air currents.

Well in answer to your thinking, rather than blasting a pile of dust I would just back off and fog it more gently adjusting the water coming into the apparatus to discharge bigger droplets rather than with fine steam.

And as far as wind goes, I have never seen a man that could not light a cigarette with a match in any kind of wind. Where there is a will there is a way.

It takes lots of energy to turn water into steam. This vaporization has a cooling effect on the fire. What you are doing is pre-vaporizing the fluid before it can cool anything.

Having a hundred mile an hour blast of air/steam will produce disaster as farmatt has suggested.

There are others who will expand on this probably, but I'd look for other ways to cool the fire.

I hate to be negative, but that's how I see it.

Well I appreciate your response and interest, but I will not give up as easily as that.

I want to know more about steam and air with its oxygen all ready used up (by the jet) and its ability to first "smother" a fire in order for it to then cool.

If the blast is not helpful, sometimes it will not be I understand, then back off and open the exit port so bigger droplets come out.

But I think the "steam" can be helpful, and advantageously efficient.

The pulse jet and the ram jet are very different animals.

The comments of the posters above are valid and appropriate.

Yes you are correct they are very different, I think I realize most of the differences seeing where either one can be utilized for the same purposes I am trying to sort out.

That is a blast of air without oxygen and the advantage of the smothering effects of steam in combination.

Ether with blast force or gentle fogging. From variable distances and depending upon the need different sizes of jet engines, really big ones on trucks and booms or small hand held ones.

Thank you Tornado, this is what I believe and think makes my idea feasible.

A pulse jet and a ramjet are not the same thing.....

For instance, a pulse-jet is what was mounted on the German V-1 Buzz Bomb of WWII and is of simple design, with very little mechanical parts to make operational.

Ramjets are another animal all together, as you need to be up to a fairly high airspeed to force (compress) enough air into the engine to fire the engine up. Also, they feature no mechanical (moving) parts to operate......geometry of the engine interior is the critical element in order to compress the air to high enough pressure to ignite the injected fuel stream.......ditto with Scram-jets (visit the NASA site to view the latest on the scram-jet test bed and technology.......they're striving to make this unmanned X plane fly in excess of Mach 10!).

I think you had better do a Google or CR4 search first to make sure you know the difference!

Good luck, and have a nice sunny day!

Just my 2 Cents added........

A pulse jet is not a ram jet. A ram jet is basically a stove pipe (no moving parts) that uses the intake air for compression and a continuous combustion.

A pulse jet has a form of gate valve that closes during combustion which is pulse gets its name from. both need airflow that it does not creat on its own, like a turbine does.

p911

15 helpful comments, I thank you all.

My question is best answered by Tornado.

The type of jet I want to or would use is really irrelevant.

All I am wanting to do is have it create a blast with less Oxygen in combination with the creation of steam being added to the blast.

Of course the amount of blast and steam are both variables, "tunable".

Does anyone else see the advantages in doing this?

In the first gulf war when the Iraqis set Kuwaitis oil wells on fire, didn't they use this jet engine concept to to extinguish them.

Yes they did, they put two big fighter jet engines on top of a tank, then fed water into the engine blast through 5 or 6 4 inch pipes. It worked. BIG equipment that just blew the damn things out.

And there are other examples doing the same thing, a coal mine fire in Russia. That did what nothing else could do.

There is a fellow who has a patent on doing some similar thing, but I can not see where he is doing any development with it. All he has is a crude drawing on file of a WWII VI pulse jet injected with water, and he is apparently just sitting on his patent "tying it up". I am thinking there is room for improvement. I want to learn more.

I have ideas over flowing in my head and need feed back to sort through them. Before I spend money on them.

I have been looking at web sites for several years and there are a lot of them all close to what I am thinking but none seem to put all the fire fighting peaces together.

To me it seems very possible and some what revolutionary.

Not rocket science just jet science. In combination with a little fire fighting common sense and ingenuity.

I have had this idea for at least 40 years and I need to get it out of my head so I can move on to others I have.

Steam I know displaces fire or the oxygen it needs to burn, smothering it. The jet blast gets the steam to the source of the fires fuel. There where the water molecules can work there magic.

Here is a link for a fire supression unit you may be interested in similar idea, different methods

http://www.aircommander.com/

All right, very good. This is what I am leaning towards.

Thank you.

I have ideas of fogging hundreds of acres of forest fires for miles around in locations where there is adequate water to feed into a 747 engine, changing the humidity with minuscule particles of water, working with natural wind currents.

One location is in a deep canyon that has a river in it near my home. It burns every year. And its slopes are relatively un assessable. The river and it's close proximity with a major highway would accommodate such a truck mounted jet engine.

But let me still emphasize the point of oxygen depleted airflow from an oxygen consuming glutton of a jet.

And also a very much smaller hand held version.

I envision such a tool blasting a fogging steam flow into a closed apartment complex, through a window. All done from a boom truck reaching up and in. Slowly with deliberation.

Thanks again, I will mark your post as helpful.

Here to like with the web site you pointed me to, I think this type of tool would be extremely useful on military aircraft carriers where equipment fires can or could be blown out. Similar to a WWII B17 diving to extinguish an engine fire. Have you seen that movie?

You keep emphasizing oxygen depletion in the steam plume, but you are mistaken for two reasons. One is the obvious one that the mixture in the pulsejet engine is not stoichiometric - there has to be excess air or the damn' thing will melt. Modern gas turbines use elaborate cooling methods for the first stage turbine blades, but even so they operate with excess air to allow the hot-section parts to survive.

Second point is that the steam plume, once it leaves the nozzle, will induce a large secondary flow of air from the surroundings and carry it TO the flame; this is how the steam-atomizing oil burners work.

Another point of confusion is that some of us are talking about steam and others about a fog of water droplets. They may look the same, but thermodynamically they are very different. Fogging with liquid water mist is sometimes used in fighting specific types of fires where the flame is very diffuse. Steam would be useless, and perhaps even dangerous, in that application.

Now that has possibilities because its probably actually also colder than the environment where it is to be used.......

Good link, thanks.

Sorry, but to repeat myself again (and several others):-

No, I see no plus in this system over other tested systems.....

The effectiveness of any fluid in fighting a fire is proportional to the rate at which it can remove heat from the heart of the fire. Water works well because, in flashing to steam, it absorbs huge quantities of heat at a relatively low temperature, thus interrupting the chemical processes that maintain the flame.

A secondary effect is smothering - simply denying oxygen to the flame.

Spraying steam would definitely reduce the first effect, because the phase-change heat capacity is already used up in generating the steam, so only the sensible heat of the steam could be increased in cooling the flame, and that process - superheating - would occur at a higher temperature.

I would think that smothering would also be decreased, because the steam plume would entrain a great deal of air with it.

There is in fact a type of oil burner in which steam is used to atomize the oil and induce a draft. It's very effective in burning very heavy fractions that are hard to light.

In short, I strongly suspect this is a dead end.