quote:

Originally posted by Graplr:
My Oberdorfer is a N993R. The R indicates that it has its own internal relief valve. I am planning on having a bypass for the extra oil, but do I still need to add a relief valve since the pump has its own?

Yes since the built-in relief valve may not be able to handle bypassing the entire flow in case the jets clogged or you forgot and left your bypass closed.

Thanks for clarifying Sun, that is what I was assuming.

Below are my centrifuge plans. I replicated Sun's design closely. The only real changes are 1 barrel heater and 1 inline heater and the barrel will be pounded down (per Skulptor's design found on p117 of this thread) and put on a reshaped and welded bed frame (per Skulptor and Flyboyd8's design also on p117). If I don't have success pounding the barrel I will tilt it as most do. I don't have any real plans of taking it mobile, but I will be moving sometime in the not too distant future so I don't want have to rebuild it when I move.



My OC20 is scheduled to be here on Thursday and I have a bit of time off then so I hope to get everything completed within a few days after that.

Here is my 'cart' design using a bed frame. I included 3 views. I will have to do a bit of welding. The pump and motor will sit lower than the bottom of the barrel.



Anyone see any issues or possible improvements with my design?
Thanks!

The pounded down bottom will work fine, I have been making bd reactors like that for years. Dig a shallow, dished hole in the ground, round off the corners of a 4x4 and work the bottome into the shape you need. Just drop in a 'death trap' heater and go for it. Or for faster results use a in line heater.

Well, I'm back.

I was limping along okay, but I went out to run another batch and again the same problem. Blocked flow. The CF wouldn't turn. Also this time not enoug pressure.

I started to take it apart again to clean out the black flakes and then just decided to re-plumb the whole thing to make it more similar to Sun's. I got rid of the in-line pressure release valve and put the ball valve going back into the tank. I got rid of the little horizontal heater and did the vertical big heater to minimize black flakes, AND I even put in a strainer after the heater.

I spent all day and just started the motor.

No pressure. No turn.

Even with the ball valve all the way closed, the gauge only reads 40psi, and the motor struggles, stops turning.

Do you think my motor could be worn out?

I just tried quickly, and the oil is still cold. I'll try again tomorrow after running a barrel heater over night.

Ideas?

quote:

Originally posted by veggiecar300:

I just tried quickly, and the oil is still cold. I'll try again tomorrow after running a barrel heater over night.

Ideas?

Sorry, I guess it was a false alarm. I heated the oil and blew some compressed air through everything again and it works. Hopefully the new setup will minimize further blockages. I got a good hot and fast run out of it this morning.

I am right with you all. I have a school bus that I am traveling across the country doing environmental education. I am just beginning the process of switching from filters to a centrifuge. I have a 50 gallon dirty tank and I have a 75 gallon clean tank hooked up to the motor. I am designing a third 30 gallon process tank in between to filter the oil with a centrifuge. I am planning on using a diverse heating approach including an oil cooler plumbed inside the tank with hot coolant running through, a 110 v hot water heater for heating while I am parked, and an inline 12 v fuel heater. I have no idea if this will get me the 160 degrees that I need? I would love to hear other ideas of getting the oil hot while on the go.

I also have to figure out how to get the water out of the process tank because it will start to condense on the top of the tank if I do not vent it properly.

My big question is which centrifuge I should buy the OC-20 or the OC-50 for a mobile application. The pump that I will be using can only get the OC-50 up to 50 psi but it can get the OC-20 up to 90 psi. I guess I am wondering which one will filter the oil faster on the road based on my heating difficulties and my 12 v pump situation.

Also flash evaporation?? what's the good word?

peace
Jonathan

quote:

Originally posted by jonathan dubinsky:
... and an inline 12 v fuel heater. I have no idea if this will get me the 160 degrees that I need? I would love to hear other ideas of getting the oil hot while on the go.

A FPHE with coolant flowing through it is the best, much better than an oil cooler since its more heat exchange area and more flow on both the coolant and VO sides. The 12v heater element may not do much and is probably not worth it, how many watts? Even special high output alternators (you may have on a bus) would have trouble putting out 100amps + other loads continuously which is how much you would need to produce even a slow heating 100amp=1200 watts compared to a FPHE which equals many times that heat with no drain on your electrical system.

quote:

I also have to figure out how to get the water out of the process tank because it will start to condense on the top of the tank if I do not vent it properly.

A fan.

quote:

My big question is which centrifuge I should buy the OC-20 or the OC-50 for a mobile application. The pump that I will be using can only get the OC-50 up to 50 psi but it can get the OC-20 up to 90 psi. I guess I am wondering which one will filter the oil faster on the road based on my heating difficulties and my 12 v pump situation.

Get the OC-20 since 50psi isn't enough for good operation.

quote:

Also flash evaporation?? what's the good word?

Yes FE is good. Try to use it since it speeds up dewatering by about 2x.

Thanks so much for the response it was very helpful. Do you think I will have any trouble with the OC-20 filling up with sediment before I finish cleaning 30 gallons of WVO?

How can I do flash evaporation in a mobile setting? I saw the posts about heating fluid in a pipe up to 300 degrees and then opening a valve at the other end and letting the steam rise out. I am wondering if there is a way to do it with a blow off valve that the steam could whistle out of with out the veggie oil rising out too. Any ideas? That would allow the system to be some what closed.

quote:

Originally posted by jonathan dubinsky:
Do you think I will have any trouble with the OC-20 filling up with sediment before I finish cleaning 30 gallons of WVO?

No.

quote:

How can I do flash evaporation in a mobile setting?

A small fan across the output of the CF. The CF jets cause FE and visible vapor starting at 120F.

Is the output of the CF enclosed? How will a fan be placed in order to blow off water vapor? I canno visualize what you mean.

Another question I am about to but a fphe and I was wondering if I should get a 16, 26, or 30 if my goal is to heat at maximum 30 gallons of WVO to 160 degrees plus. I am guessing bigger is better? Is there a preferred product or brand in this instance? The one that Plant drive sells comes with a mounting bracket and plastic fittings for 138 plus shipping.

Thoughts?

Jonathan

Okay, I got everything put together and am currently running the fuge. I waited until the oil was 120F to start it up. I closed the bypass a bit and the pressure rose. Then I closed it all the way and it rose a bit more...but only to 60 PSI. My first thought was my pump has a relief valve so I tighted it but it is about as far in as it will go. So unless I'm doing something incorrectly, it is not the relief valve.

My two thoughts-
1-My oberdorfer is a 993. Perhaps I need more than a 1/2 HP motor to run it? Doesn't seem like it should but...

2-I have something put together incorrectly on the fuge (oc20). I can hear it spinning and wvo is coming out the bottom.

Help?

Thanks,
Ryan

I have spoken with the pump mfg. If the bypass is closed down and the PSI is only 60 the pumps may be worn past acceptable limits. 1/2 Hp is more than enough.

Was the pump new or used?

Used, but it doesn't look like it was heavy use. It is still shiny.

It looks like I'm having a similar problem. My motor is struggling, and is sometimes throwing sparks when it works too hard. It's a used motor.

How can I tell if the pump is worn or the motor?

Here's pics of my rebuild, to be more similar to Sun's with the vertical heater.




That's about where it sits, just below 80psi, almost completely closed. I had more success yesterday morning, after I had the barrel heater on all night. This morning, I tried it cold and the motor was really struggling and threw sparks. I'll try again after I've had the barrel heater on for a few hours.

The temp of the oil in the tank is around 75.

Another thought. Perhaps I have the pump pumping 'backwards'. In looking at the specs here-
http://www.oberdorfer-pumps.co...eets/N993_series.pdf

I noticed in the pic of the pump with the relief valve on the 2nd page, the in is on the opposite side of mine, but the relief valve is also on the opposite side. So both things are opposite.

Wish I would have put a tank valve BEFORE the pump. Then I could just close it and take the pump off and switch things around.

I have about 20 gallons in there and have run it for about 3-4 hours at 160+F and 55PSI. I stopped (captured the output) and cleaned the rotor. There was a fair amount of crud in it, so even at this low PSI it is still cleaning.

Can it work at PSIs this low?


I'll pump the oil into another container and switch it around and see if that makes any difference.

When it comes to gear pump wear it all gets down the the clearance between the gears in the pump. The factory will be able to measure the parts and advise...I am not sure if you can determine the wear based on just looking at it.

I believe the factory will evaluate the pump at no charge. Repair of a 993 may be $300-$400 but do not hold me to it.

As for used motors I would assume if it is throwing sparks and getting hot it is near death. Motors must be at least 1/3 HP. Less than 1/3 HP is too small. But to be sure we need the motor RPM, HP and complete pump specs.

The open flow is great. It filled a 5 gallon bucket in well under a minute. Can the open flow be to spec but not be able to get PSI?

I just emptied the barrel and now I'm turning things around to the way the pic looks.

Yes it can FLOW lots and create minimum PSI.

Called the pump engineer again to confirm the direction only matters if we are trying to use the internal bypass. It will pump either direction but only bypass in one direction.

quote:

Originally posted by Mr Dieselcraft:
Yes it can FLOW lots and create minimum PSI.

Called the pump engineer again to confirm the direction only matters if we are trying to use the internal bypass. It will pump either direction but only bypass in one direction.

I was hoping the bypass was the problem and switching direction would solve it. But I only can get the motor to run in one direction. So now it flows into the tank.

I realized this motor is a backwards motor (it is labelled that way...duh) which is why the pump was set up backwards. I have a regular motor in my friend's garage. I'm going to get it tomorrow and see if it changes anything.

FYI- when I had everything off, I looked at the gears and they looked real nice...no chips. But like you said that may not mean anything.

quote:

Originally posted by jonathan dubinsky:
Is the output of the CF enclosed?

Its threaded so you do what you want, open or closed.

quote:

How will a fan be placed in order to blow off water vapor? I canno visualize what you mean.

A cross fitting with 2 elbows with pipes going up from it, with a fan blowing through those. Or a fan blowing through 2 fittings in the top of your barrel which isn't as good since you get more condensation. Many more combinations are possible.

quote:

Another question I am about to but a fphe and I was wondering if I should get a 16, 26, or 30 if my goal is to heat at maximum 30 gallons of WVO to 160 degrees plus. I am guessing bigger is better?

Bigger the better for this.

quote:

Is there a preferred product or brand in this instance?

They are all very similar, you can find them on ebay for the least I have seen.