kerosene in low temps

Any ideas for a faulty flow of usually reliable kerosene for CH boiler.

Reply to
Phil Donnelly
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on 09/01/2010, Phil Donnelly supposed :

Plug of ice in a pipe?

Reply to
Harry Bloomfield

That would have my bet. Oil floats on water so water collects at any low points in the pipework.

Reply to
Dave Liquorice

At Aviemore with deisel engine we used to thin with a small amount of petrol.

Reply to
Stewart

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Stewart" saying something like:

Not thinning it - keeping the waxes dissolved.

Also, mentioning putting petrol into diesel isn't relevant to a heating oil thread. It would be pretty stupid putting petrol into a kerosene tank.

Reply to
Grimly Curmudgeon

Stupid, as in dangerous, ill-advised or just pointless? (Assuming we're only talking a small percentage of petrol). Just curious.

Reply to
Dave Osborne

Pointless. Diesel fuel doesn't "freeze", and it doesn't "freeze in the pipes". What happens is that Summer-grade diesel contains waxes (they're removed for deep-Winter grades), and these waxes freeze, freezing out as fairly large crystals. As the crystals separate from the diesel (i.e. they form "clots"), a little wax can go a long way to stopping an engine that has a small fuel filter (with small pores) or the valves of an injection pump. If you decant a small sample of "waxed up, frozen diesel" you might not even be able to see the difference, yet it's enough to block a filter (try filtering it through cold filter paper though, and see what residue it leaves).

There's a lot that can be done to reduce this effect:

  • Dewatered fuel. Water is generally bad here, but not so you'd notice. A plug of water settling out in the bottom of a pipe bend and freezing solid is more of a problem.
  • Dewaxed fuel. Winter blends, which come in a range of severities.
  • Heating the fuel, usually electrically (wrap band on the filter casing). For mild UK Winters, this is enough. The injection pump is warm enough already to not be a problem.
  • Heating the fuel. Some Eastern European kit has a separate header fuel tank that's heated by the engine (usually oil-heated, as engines designed for this weather are often air-cooled). This tank contains enough fuel to start and warm through the engine, and it has a mains- powered plug-in heater for starting.
  • Redesigning the injection pump, so that valves aren't jammed by wax buildup. Mostly this involves smoothing out ports and paths so that crystals aren't trapped to gradually build up, but are instead continually washed through by the bulk fuel.
  • Moving the fuel filter inside the engine bay. Trucks with chassis- mounted filters suffer much worse than cars.
  • Diluting the fuel with a convenient wax solvent, e.g. petrol. This isn't about "antifreeze for fuels", it's just about dissolving that small proportion of wax in a solvent that doesn't give it up so easily.

In a heating boiler, there's no high-pressure injection system as for a diesel engine, so clearances are bigger. A bit of wax isn't going to stop it anyway.

Reply to
Andy Dingley

Thanks for that Andy. However, GC actually said that putting petrol in a

*kerosene* tank was stupid. I was wandering if this was because it would be pointless (as there is no wax in kerosene) or dangerous (because the boiler might explode)?
Reply to
Dave Osborne

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Dave Osborne saying something like:

I was thinking of the danger aspect. It *should* mix well, but what if it doesn't and a slug of petrol gets drawn into the fuel line? Also, raising the volatility of a kerosene fuel in a domestic burner (or any flame application for that matter) strikes me as foolhardy. Again, who knows what ratio to add, it might take very little to cause a problem.

Lobbing a gallon of petrol into a diesel tank on a truck or other plant is a different thing entirely and is a practice which has been carried out for decades, quite safely.

Reply to
Grimly Curmudgeon

Until about 15 years ago the US and many others in the polar regions used to use a 50-50 kerosine-petrol mix (called JP4 or F40 or AVTAG) precisely because it didn't freeze until about -60 deg C meaning it could often be kept under cover or buried in a snowbank until it was needed. It is a bit of a dodgy fuel though needing very careful handling but it was extensively used for cooking and space heating purposes by almost every one of the Polar bases.

Reply to
Mike

That would be my bet as well. Kerosene attracts water almost as much as a piece of meat hung from a tree attracts bluebottles.

It is a well known problem with jet aircraft and I would suggest a regular check for water from the feed from the tank. Get a small jam jar and get some fuel into it and let it settle. You don't need a full jar, as the water will be the first thing to come out.

Dave

Reply to
Dave

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Mike saying something like:

Military expediency, fine. Domestic - nonono Nanook.

Reply to
Grimly Curmudgeon

I've done a bit of googling because I don't have my oils and fuels books any more. Wouldn't it be AVCAT that was mixed with chemicals that prevent it from freezing?

I've worked with AVTUR, AVTAG and AVCAT and I don't remember any of them smelling of petrol, but the AVCAT did irritate the skin a lot.

Perhaps the addition of petrol was done to allow easier starting in the cold regions of North America. This subject came up some time late last year in this ng.

Dave

Reply to
Dave

JP-4 - the original purpose behind it was for storage on carriers with mixed piston / jet fleets. It's a literal mixture (on demand) of AVGAS from the piston engine tanks and the kerosene component. AFAIR this kerosene was a ship boiler fuel oil.

JP-5 was a raised flashpoint fuel that replaced it, for better safety on carriers.

JP-6, JP-7 & JPTS were the skunk works specials.

JP-8 is the modern replacement. Supposedly cheaper to make, it's also less flammable, less chemically hazardous, and can be used in colder weather. It's standard kit as a non-gasoline Arctic fuel, for everything from helicopters to stoves.

Reply to
Andy Dingley

Claptrap - you obviously haven't had any experience of removing wax from heating boiler fuel lines in cold UK winter weather, nor of clogged burner nozzles!

Reply to
cynic

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