When I introduce methoxide in my Appleseed I tend to have a heck of a time getting it inject.
I have the methoxide introduction plumbed between the drain and pump. My methoxide introduction consists of a ball valve and a one way check valve. I open the ball valve for the methoxide and partially close the drain valve, after the oil is heated to 130F.
Some oil continues through from the drain past the meth intro- to the pump recirculating through the processor with the methoxide being introduced into the stream of oil.
The problem I am running into is I get air sucking in from somewhere, which in turn intermittently stops the flow of oil through the pump.
If I open the drain valve more, the oil continues to flow. When I close it down the meth will inject for a second or two and the the flow tends to 'stall' with more air and then flow resumes for a few seconds, then stall's, and so on.
One thing I've noticed is this will go on until the temperature falls to around 120F, then she injects fast as a wet dream.
I have taken the plumbing apart, used new teflon tape, tightened and re-tightened fitting's and connection's and still am experiencing this problem after one year of using this processor.
At first I thought this may have been a faulty check valve, so I replaced it.
A friend asked where I bought my ball vavles.
They are Harbor Freight valves(inexpensive).
He told me that is the problem cause they are made in China. Poor casting methods allow air leaks. He went with valves made in Taiwan which a plumbing parts supplier recommended were superior.
What do you think? What else might be the problem.
Oh yeah-- that was the short version.

Your air leak is probably around the shaft seal in the pump.

Try lifting your methoxide tank a couple feet (be safe)

How sure are you of the actual temp? Could it be hotter? It might be that the methanol is flashing to vapor at the pump causing it to lose prime.

Tony

quote:

Originally posted by tgomes:
How sure are you of the actual temp? Could it be hotter? It might be that the methanol is flashing to vapor at the pump causing it to lose prime.

Tony

If the oil is wet enough, the same flashing will occur at lower temperatures.

Um, do you have a vent open when introducing the methoxide or is the whole system closed ?

I'll attach a pic of my plumbing including the temp. gauge placement.
Umm as far as the vent goes, I leave it open while introducing the methoxide and close it after the meth is introduced.

BD_thermometer_07_057.jpg (24 KB, 22 downloads)

How long is the probe of the temp gage? If it is not in the flow (protruding into the tee) then it is in a dead leg and will not be as accurate as you might like.

Tony

http://www.utahbiodieselsupply.com/images/Thermometer1.gif
connected to a 45* 1/2" elbow.
The probe length reaches the center of the elbow. It does not touch the inner wall of the elbow.

It needs to be in the flow. Install tee between the current tee and the 4 way tee. In the elbow as it is it is a couple of inches from flowing oil.