Running a Diesel Engine on compressed Air?

[Norsk]

My old wooden house sits 100m below an old growth forest, should the forest catch alight it will rain embers upon my house most likely setting it allight.

I have thought about installing a mist system to wet under the eves and along the masonary walls where the timber cladding meets the foundation. These are the most likely places for a fire to catch.

I would have 5000 liters of water in tanks uphill of the pump so that would always be primed. However the pump might be starved of air by the draft from the forest fire? Could I conceivably run or at least suppliment a two cylinder diesel engine using compressed air? How much would I need per hour?

 

[hotponyshoes]

You'll need an awful amount of air to feed an engine.
Basically the engine capacity X the rpm

 

[finyuk2005]

Air Flow (CFM) | Widman International SRL

www.widman.biz

that would give you a rough idea,
quite a considerable amount!

 

[hotponyshoes]

If you are planning on feeding it air from an electric compressor why not just use an electric water pump?
Probably not much use unless your electric supply is under ground

 

[hotponyshoes]

A 600cc engine running at 850rpm will need 30600 litres of air an hour.
150 litre 10 bar air receivers are quite common, you'd just need to find 20 of them...

A tank of nitrous might be more practical..

 

[OJCar]

At what rate would the missing system consume the water ?
1000 litre an hour?

 

[awemawson]

Why not install an elevated water tank - pylon sort of arrangement - once it's full no power required

 

[dave h 2]

My old wooden house sits 100m below an old growth forest, should the forest catch alight it will rain embers upon my house most likely setting it allight.

I have thought about installing a mist system to wet under the eves and along the masonary walls where the timber cladding meets the foundation. These are the most likely places for a fire to catch.

I would have 5000 liters of water in tanks uphill of the pump so that would always be primed. However the pump might be starved of air by the draft from the forest fire? Could I conceivably run or at least suppliment a two cylinder diesel engine using compressed air? How much would I need per hour?

metal mesh to stop embers lodging in the gutters would help a lot. A firework lodged in the gutter of our post office and burnt it out.

 

[hotponyshoes]

Do the maths to check but I reckon you'd use a lot less air by using air to blow to the water out of a pressurised tank rather than feed a diesel engine.
Or even use an air powered pump.

 

[addjunkie]

If the fire is above the house in the forest, there should always be air on the ground, in that as the heat from the forest fire lightens the air above it, cold fresh air will be drawn from the sides below, or the fire would go out.

Also as you have static head from your tanks, do you actually need a pump. What height above the risk area is the tank? Water mist systems normallystop and start to 8n effect dampen an area. Stored pressure from cylinders gets the mist

 

[Gareth J]

The air will be moving sure. But there'll still be air around and it'll be air that is moving. An engine will have no issues running. Consider a vehicle that drives at 100mph, it's air supply is not an issue. Much more windspeed than that and you'll have other issues to deal with!

 

[frank horton]

Also the size of the water delivery system to the house needs careful consideration……
when I worked for the fire brigade just one of their pumps on full chat would drain a 4-6 inch pipe of water….

 

[frank horton]

Sorry. For Better info look at what’s required in California…..
loads'a info out there…..

 

[optima21]

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

 

[Norsk]

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.

 

[roofman]

Re-setting the gutters so they are always half full of water would help.

 

[knighty]

a small petrol powered pump should be more than enough for what you need ?

you don't want to use a pump that's too big or you'll drain your 5000 litres and be left dry?

if you setup to catch rain water you could put a sprinkler on your roof, so it wets the roof and over the edges of it... you could start that running early to keep the whole area moist... if you're catching the water that runs down your gutters to use again then non is wasted?

 

[bricol]

. . . looks up non-combustible cladding types . . . ?

 

[8ob]

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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[roofman]

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 in about three hours, enough water to keep a playing field wet for that amount of time.

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