3B SVO fuel temperatures.......

[magnus_heydoc]

Hey guys,
So I've been trying to get higher temperatures with my SVO rig. I run two tanks, the details are here:
http://forum.ih8mud.com/alternative-...-up-my-3b.html

The problem is I'm only getting anywhere from 120-150F depending on the aimbient temp.
I recently changed thermostats as mine was about 5 years old and the temps are the same.

I may simply have to insulate to the nth power. Temp definitely drops when I'm in the wind.

Can anyone running a 3B shed some light on this? I'd rather not re-invent the wheel eh?
(holla if you hear me; usual suspects.......Gault, Frank James etc.)

[John Galt]

What is the coolant temperature entering the FPHE?

Is the FPHE connected in series with the other coolant heated loads like the filter and fuel pick-up?

That's the usual cause of insufficient heat. The FPHE should have it's own coolant loop in parallel with the other heaters in series forming another parallel loop.

[magnus_heydoc]

The coolant temp imediately exhiting the FPHE is 180F+ at operating temp. The probe in the 'common lines' just downstream from my valve gets to 150F at it's very hottest and is mainly b/t 125-145F.

The only probe I have prior to the FPHE is way back in the veggie tank. Back there with a HFPU and a heat pad (250w) underneath it gets to somewhere b/t 100-115F. Back there that's ok to me as all it has to do it become fluid enough to begin moving well into the aux. HOH bundle.

I'm convinced the FPHE is simply to far 'upstream' from my valve. If I was to do it again I'd put the exchanger imediately prior to the valve.

So here's the latest (no laughing)..............................

We're going to buid a section of stainless into the exhaust and loop a hard fuel line coil around it. If a 800-1000F addition doesn't get me enough heat I'm not sure what will. It's time to get some serious heat!

[magnus_heydoc]

The Smoke Point

Actually, Ol' Francisco and I were talking and he said we could do a couple tests on a hard coil line of water say. Water boils at 212F. We could see how many coils around the exhaust it takes to get boiling h2o. When it gets really crisp here in NB it might be good to shoot for about 250F and let it cool a bit in the line and by the time it gets to the common lines it'll be 180F. How much can veggie take before it cokes up? Here's some info on smoke points. It appears cranking things up to 375F would be fine as that's what most fryers operate at.

"Knowing the smoke point can also save you money, because each time you deep-fry, you lower its smoke point irreversibly. If your oil's smoke point is just above 190 degrees C (375 degrees F), which is the normal deep-frying temperature, chances are its smoke point will drop below 190 degrees C (375 degrees F) after its first use, rendering it useless. If you want to save money by reusing an oil as many times as possible, select one with a high smoke point."

Smoke Points
Safflower 265 degrees C
Sunflower 246 degrees C
Soybean 241 degrees C
Canola 238 degrees C
Corn 236 degrees C
Peanut 231 degrees C
Sesame 215 degrees C
Olive 190 degrees C
Lards 183 to 205 degrees C

[John Galt]

I'm convinced the FPHE is simply to far 'upstream' from my valve. If I was to do it again I'd put the exchanger imediately prior to the valve.

Can the valve stand the heat?

It might be easiest to simply insulate the fuel lines from the FPHE to the injectors.

Everyone who has tried exhaust heat for oil has found it caused a lot of problems. But hey, maybe you will be the first one to make it work. The exhaust heat is too high, quite variable, and causes the oil to polymerize then burn, clogging the tube. Be sure to have a filter downstream to catch the burned crud that flakes off the inside of the heated tubing.

Hundreds if not thousands of people use FPHEs successfully, are you sure it's installed correctly? Is it mounted vertically? Is the fluid flowing in the correct crossflow directions, i.e. is the oil output beside the coolant input?

I suggest getting a simple inexpensive automotive inside/outside thermometer, and attaching the remote probe to the OIL output line from the FPHE. Wrap the probe with some insulation so it reads the fuel line temp accurately. Then monitor the temperature as you drive at speed.

[magnus_heydoc]

JG,
I'm pretty sure the temp is accurate and the FPHE works just fine. If you look at some of the pics you can see the probe placement. My HE is mounted horizontally but the probe (ina compression fitting directly in the fuel stream) reads 180F --------perfect BUT by the time fuel gets downstream to the valve it cools to 140F or so. It seems if my FPHE was really close to the valve there would not be enough surface area to disappate the heat and then I'd stay closer to 180F. I'm hesitating tearing the whole thing appart and moving the HE more downstream and that's why I'm considering an additional heat source. If I could somehow regulate the heat garnered by exhaust.................
Yeah it's insulated like a mofo now. The valve is a GC 6way. I'll check and see what it can take.
What can the oil take generally? 275F?
tha experiment continues.........

Aaron

[magnus_heydoc]

So for all those tuned in out there in internet mud land FPHE's work extremely well; the key appears to be make sure they are very handy to the switching valve. That way by the time the oil is into the common lines (2 tank systems), it'll still be wicked hot.

[John Galt]

Sounds like you solved your problem.

[magnus_heydoc]

Yes ideally I think that will solve it but I'd rather not tear appart my system. I'm gonna try to add some heat somehow. Although it's another expense I may just add another exchanger.
We'll see.
One things for sure it'a a continual experiemnt.

[magnus_heydoc]

OK so here's one flaw in my set-up hopefully all the rest of y'all can avoid.

Previously, the SVO came from the tank and then in this order:
1)FPHE
2)Filter; Parker/Racor
3) through some stainless hard lines
4) GC valve.

This got me to 140F or so at highway speed

So now the new set-up is:
1)Filter
2)FPHE
3)Hard lines
GC valve

This gets me tp 160-170F at highway speed.
Clearly, the HFPU heats the oil to 112F or so which seems to be enough to filter ok. The deal is that the filter holds a litre or so and it lets things cool off far too much. The FPHE should be the very last step before the valve.
For what it's worth.................