hot pan test issues

Collecting, filtering and dewatering of WVO SVO vegetable oil. For Biodiesel producers too.

Moderators: SunWizard, coachgeo

hot pan test issues

Postby ecojetta » Sun Mar 23, 2008 9:54 am

new post started for some confusion I was having on the HPT:

The oil appears to pass the hot pan test, BUT I have an issue with the test that is confusing me. After the pan is smoking, and I pour in the sample, I see upwelling with no bubbles, but then I start to see some small bubbles forming near the sides of the pan at the oil/pan interface. They stick to the pan and look weird. This did not happen when I did the test with an iron skillet on my gas grill running wide open. I wonder if it has to do with the no stick pan. In fact, I cannot even get a smear of oil to not coalesce into droplets in this particular pan.

I got this oil from an experienced veggie guy who said it was a good dry source. I have repeated the dewatering process several times using the rig shown at
Single Barrel Filtration/Dewatering Rig - design details

I tried pure veggie oil out of the Wesson bottle and this did not happen.

I added a small amount of water on purpose to my oil sample and got normal looking bubbles immediately. thanks for that idea.

I did add a solvent to the WVO (it was a diesel fuelinjector cleaner / biocide/algecide) I wonder if this is what is causing the strange result.

I think it is time to try the weight/heat/weigh method.
120k
04 Jetta TDI with Greasecar 2 tank kit
ecojetta
 
Posts: 20
Joined: Wed Mar 12, 2008 9:46 am
Location: New Kent, Virginia

Postby SunWizard » Sun Mar 23, 2008 10:51 am

Thanks for starting a new topic, what good forum manners you have.

I think its the solvent. Easy fix, don't add that before a HPT. :)
YVORMV - Your veg. oil results may vary.
95 Dodge Cummins 4x4 SVO WVO conversion.
81 Mercedes 300D- stock and happy on V80/D20 blend.
Low fossil net zero house- 100% solar power and heat.
SunWizard
Site Admin
 
Posts: 1723
Joined: Mon Dec 11, 2006 2:53 pm
Location: N. Colorado

Postby John Galt » Sun Mar 23, 2008 11:41 am

I agree it's the solvent, not the pan. It's always important to 'calibrate' one's HPT observations with fresh store bought oil.
John Galt
 
Posts: 526
Joined: Tue Mar 04, 2008 9:17 pm
Location: Coldest North America

Postby SkySkiJason » Mon Mar 24, 2008 11:31 am

CONFIRMED!! Bio-d, diesel, other flammable additives give false indications in the hot pan test. This is for the same reason we got a 'false' reading with the flashpoint test I did Saturay. The lighter, flammable components evaporate at temps below the 350*F we are shooting for in the HPT.
2001 F-350, DRW, 4x4, XLT Crew Cab, flat bed, 7.3, 6 spd, Dipricol Optix gauges, DP tunes - Single-Shot injectors! Vegistroke-style WVO conversion, 55,000 VO miles so far - 190 deg VO before the heads
SkySkiJason
 
Posts: 57
Joined: Wed Mar 19, 2008 2:06 pm

hpt in teflon pan

Postby wvoalaska » Mon May 05, 2008 4:21 pm

Just a note: I wouldn't use a teflon coated pan for the hot pan test. At higher temperatures, teflon releases some nasty gasses. I know somebody whose birds died as a result of overheating teflon with butter in it.
wvoalaska
 
Posts: 4
Joined: Wed Mar 05, 2008 3:33 pm
Location: Alaska

Small Particles Dancing

Postby newtoveggie » Sat May 10, 2008 8:58 pm

I have an interesting occurrence happening with my Hot Pan Test after CF run. The Iron skillet is brought to 400 degrees, the sample is poured in and small specs start dancing around in a zig zag pattern. They remind me of proton and electrons moving around each other. Any ideas? Do bubbles look shiny? I have a Dewalt light aimed at the pan.
How can you tell the difference between air bubbles and water bubbles? The CF does a pretty good job mixing air into the oil right? Another sample I put in a mason jar had a ton of little bubbles that went to the surface after an hour or so and now no more bubbles. Is that air?
newtoveggie
 
Posts: 20
Joined: Fri May 09, 2008 11:07 pm
Location: Andover, MA

Re: Small Particles Dancing

Postby SunWizard » Sat May 10, 2008 9:45 pm

newtoveggie wrote:I have an interesting occurrence happening with my Hot Pan Test after CF run. The Iron skillet is brought to 400 degrees, the sample is poured in and small specs start dancing around in a zig zag pattern. They remind me of proton and electrons moving around each other. Any ideas?

Sounds like its too hot, did you smear a thin layer on the pan and pour VO in when it started to smoke?
Do bubbles look shiny? I have a Dewalt light aimed at the pan.
How can you tell the difference between air bubbles and water bubbles? The CF does a pretty good job mixing air into the oil right? Another sample I put in a mason jar had a ton of little bubbles that went to the surface after an hour or so and now no more bubbles. Is that air?

In warm >140F VO the air bubbles go out quickly, <2 minutes. The water which turns to steam on the pan surface are much bigger bubbles than air. Did you try a hot pan test on the VO before CF? Try some nasty bottom of the barrel VO (with no free water) to see what the bubbles look like in a pan test.
YVORMV - Your veg. oil results may vary.
95 Dodge Cummins 4x4 SVO WVO conversion.
81 Mercedes 300D- stock and happy on V80/D20 blend.
Low fossil net zero house- 100% solar power and heat.
SunWizard
Site Admin
 
Posts: 1723
Joined: Mon Dec 11, 2006 2:53 pm
Location: N. Colorado

See Hot Pan Test Confusion

Postby newtoveggie » Sun May 11, 2008 9:02 am

It just so happens the smear of oil from a previous HPT smokes when the heat gun measuring device reaches 400 degrees when aim at the cast iron skillet.
I did try a HPT prior to CF. Clearly there is cracking occurring and the shiny particles are more numerous.

I started a new thread on this topic "Hot Pan Test Confusion".
newtoveggie
 
Posts: 20
Joined: Fri May 09, 2008 11:07 pm
Location: Andover, MA


Return to Vegetable oil Collecting, Filtering and Dewatering

Who is online

Users browsing this forum: No registered users and 0 guests

cron