Running a Diesel Engine on compressed Air?

[8ob]

Thats some turfing project..only a few bits dropped out the fight for life too.

We were called in to rescue the project, a landscaper had laid the whole lot without thinking about the watering of it( there was no water on site at all ), managed to save the whole lot, took about three weeks.

Bob

 

[chunkolini]

This is why I love this forum.
Obscure requests are respected and answered with quality information
often in mnutes

 

[minimutly]

Some great replies. I cannot get the tanks high enough above the house to produce enough head.The power lines run along the forest edge so a lekky pump is not an option.

I think it might be best to pipe a air supply into the pump from from 50 meters down the hill towards the sea.Burry a 4" flexable pipe in a trench.

An old grow forest produces an insane amount of heat and consumes vast amounts of oxygen. Since my house is below the forest thats a big plus, since most of the smoke and heat will go upwards. I would put the engine and pump in a disused concrete tank below ground level.

So you’ve answered your own question. You need a pump/compressor that supplies your engine driven pump with the same amount of air it consumes (+ 10 % assuming your pipe work is big enough).
It needs to be airtight, with a blow off valve.

 

[DAPPH]

older diesel engines used (and still are) started on compressed air, but you many be looking at 250 to 600psi air pressure to turn them over

Air starters on the Meadows 30 KVA Genny's used 120 psi air in the reservoir , the same as all British military wheeled vehicle engine driven air compressors for brakes etc.
What was said about the fire heat rising and fresh air been drawn in at ground level is true stop that supply of oxygen and the fire cannot burn . So long as the air intake to the genny is well away from the building and has several hot ash deflecting screens under a solidly built structure with the rest of the air inlet pipe buried a few feet below the ground I don't feel that oxygen starvation will affect things much
You could even use an air inlet pipe in a big cleaned out vertical cylinder half-full of water , that has the inlet air to the engine at the top of the tank well above the water level . Where the actual inlet air has to be drawn through the cooling water in the lower half of the tank .

Metal piped brass sprinkler heads for your roof line etc are available in all sorts of spray patterns from the flicking on /off over a full circle , to fine almost micro misting in a full continuous 360 diameter over several metres .
Having them raised up on the roof line or above by a metre or two could give a massive cooling wet footprint .

Look for horticultural spray heads or similar .

eBay # 195682429673 miught work in a trial , gravity fed then pumped via a balancing chamber on to your building . There are others that do a continuous 360 rain spray made in brass rather than the pulsed ones but I can't find one at present

This fire sprinker might also be useful in your thinking , it triggers at 93 oC or so would they work inverted ? Are they available without the heat sensitive capsule in them so as soon as the water is pressurised and turned on theyb all breakn out in a spray . What is the water consumption per head & at what pressure.
eBay # 225182075036

 

[Norsk]

Thank you to the many who have replied.

I think the following systen will be the way forward:

Water tanks above the pump.
Pump in a tank below ground
Pump Air supply from 4" pipe with intake 50m below pump
Spray heads under eves and along roofline.

I already have removed all the shrubs and trees from around my house. I will clear all the grass and cover with gravel 1 meter out from the foundations.

 

[hotponyshoes]

Are you going to have some sort of automatic trigger system?
Or just hope you are at home when the trees catch fire?

 

[Norsk]

Are you going to have some sort of automatic trigger system?
Or just hope you are at home when the trees catch fire?

I place my trust in Mystic Meg.

I will come up with a system where I can call to start it. Fire season is only a few months and my neighbours are farmers so if it dosnt start up they or me could do it.

Unless the fire starts directly over the road from me it will burn from one point following the wind and terrain.

 

[GRW]

How much land downhill from your house do you have where you might site kit?
I'm thinking it's easier, cheaper and more robust perhaps to have a backup generator downhill, run armoured cables up and have an electric pump up by the house?
If you got creative & a Remote Start genny - then you could also automate it (something like a heat sensor to trigger a volt-free contact, which starts the genny, with a delay timer* on a contactor* on the genny output (so the genny gets chance to start & stabilise before the contactor closes & feeds juice to the fire pump).

* not a new idea - Lister-Petter used to supply their R-Start T-Series gensets with a timer-contactor box for off-grid duty, so when the set was started it didn't dump a rising voltage & frequency onto the house appliances, while it's a standard feature in auto-backup systems etc.

 

[Norsk]

Heaps of land below the house but above the house is less steep.

 

[8ob]

Heaps of land below the house but above the house is less steep.

Would it be possible to place your reservoir of water uphill and make your system gravity fed? 100 feet of head and adequately sized pipe work to your sprinkler system would be a match for any pumped system , also would not be reliant on an engine or electrical supply to work. Just thoughts

Bob

 

[Norsk]

Would it be possible to place your reservoir of water uphill and make your system gravity fed? 100 feet of head and adequately sized pipe work to your sprinkler system would be a match for any pumped system , also would not be reliant on an engine or electrical supply to work. Just thoughts

Bob

Its not possible unfortunatly. Best I can do is water tanks above the pump.

 

[GRW]

It's a lot easier for a water pump to "push" water up than to "lift" it (hence the popularity of submersible well pumps).....
So would it work for you to have the pump down & away from the house in clean air - then pump the water back up?

 

[mtt.tr]

Our Bedford bowser had a silly little single cylinder diesel pump on the back and that would run six of those wirly gig sprinklers flat out, that would empty a 1500 gallon tank in about three hours, enough water to keep a playing field wet for that amount of time.

• 

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Do you own Tracy island

 

[Morrisman]

Of the diesel engine is starved of air then in the house will too.

older diesel engines used (and still are) started on compressed air, but you many be looking at 250 to 600psi air pressure to turn them over

Most all diesel engines on ships are started by compressed air, normally just shop air too, 100 psi.

 

[Morrisman]

Are you going to have some sort of automatic trigger system?
Or just hope you are at home when the trees catch fire?

If there's not enough air to run a diesel engine I'd hope nobody is in the house at the time of the fire.

However, unless the fire miraculously pulls a near vacuum in the surrounding areas there will always be enough air/oxygen to run the engine. If there weren't, the fire would go out....

As with firestorms, the air pulled in at ground level can be so violent it moves cars etc.

 

[GRW]

Of the diesel engine is starved of air then in the house will too.

Most all diesel engines on ships are started by compressed air, normally just shop air too, 100 psi.

I get to see the odd comp-air start engine (generally a small ship engine used as a big genset prime mover).
In Port Talbot there is 1 (of 2 originally) WH Allen 8-in-line (about 1100Hp @ 750rpm) which has an ingenious cam-timed brass air-valve system which injects compressed air into each cyl at the right time to turn the engine over (if they stick the engine just rocks back& forth).
Near Haverfordwest is a beauty - a 16-cyl (2 x 8's in parallel) Ruston. 2980Hp @ 750rpm, each bank of cyls has a huge Napier Supercharger, and the engine has a permanent steel gantry walkway around it so you can get up to the cylinder heads. Maybe a minnow in shipping terms, but still impressive when you walk through a door and see it.

 

[Robotstar5]

I think they went overboard on fire suppression when they put up the Metro building at Longbridge, electric pump with a back up, if the power went out there was a diesel pump and if all else failed there were two big tanks built into the hillside above the factory that would keep the sprinkler system running by gravity for 20 minutes, from building in the late 70's to demolition in 2008 it was never used.

 

[gaz1]

a few questions here

what land do you own
how far away is your property from the trees
i note you say your on a hill is there trees below you

id advise cutting down anything that can burn within 2 metres of the house not 1 metre

i note your worry of the property, you have to understand no matter how much water you pour onto that property it wont stop it from burning down

prevention is the key here and also where best to build your property

 

[awemawson]

The Bell Common and Holmesdale tunnels on the M25 have huge tanks to receive spillage from tankers in times of accident. The fire suppression system is a large diesel engine whos exhaust is used as the source of inert gas to flood the tanks.

 

[GRW]

I think they went overboard on fire suppression when they put up the Metro building at Longbridge, electric pump with a back up, if the power went out there was a diesel pump and if all else failed there were two big tanks built into the hillside above the factory that would keep the sprinkler system running by gravity for 20 minutes, from building in the late 70's to demolition in 2008 it was never used.

Old Covent Garden Market had similar - a massive water tank, & the pumps were powered by a Rolls-Royce V12 diesel.