I have a 40 gallon biodiesel home brew system. The motor in my unit is rated at 5.5 gpm. I will be adding a filtration system in the next week that uses Eco2Pure as the media. I called the Eco2Pure folks and they recommended a flow rate of between 1.5 and 2.5 gpm. So I need some sort of flow regulator that will reduce my 5.5 gpm output to around 2 gpm.

Any ideas on how I can accomplish this? Haven't had much luck finding anything at my local stores.

Steve

There are a few methods you can use. One being a metering pump (pricey) that you preset to the flow you want. Then there is the flow meter, a gadget that installs inline to control the flow rate
(pricey)but may still require a by pass to handle the back pressure created.
The third, and the one I use (cheapest), is a by pass system using ball valves preset to the disired flow rate.This is not by any means a super acurate method, but I keep mine below the max for added residence time, and it works very well. To set it up you need to have a single line coming from your pump which then breaks into 2 lines;one is to return to the originating tank and the other goes to your filtering media beds. The one going to the filtering beds is controlled twice; once at the outlet for pressure control and the other just before the beds for flow control.
To set up for flow control you simply adjust the ball valve's handle to the open position that gives you the flow you are looking for. Then remove the handle so it doesn't get accidentally bumped. This will give you a steady and controlled flow rate without putting unecessary back pressure on the pump.The line going to the filtration beds should be in front of the return line to the tank.

pump -> outlet ...filtration beds ball valve ->
return line to tank ball valve (in case you need to give the other one a litle push).
The plumbing is simple too; pump,nipple, T fitting with ball valve in the upflow position for the filtration media, nipple, elbow to return line ball valve - a by pass system made easy.
Now to avoid unecessary grunge getting into the media I use a standpipe in my tank and then draw from it rather than the floor drain for the resin beds aftre having partially demethed and settled the biodiesel.

HTH

Legal Eagle,

Thanks so much for your valuable input. It helped me a lot. I do have a few follow-on questions about your setup. Although I read you response a few times, I could not fully understand the need for the second ball valve. It seems as though if you go from the pump output through a T, then through a ball valve, you should be able to set the ball valve to whatever flow rate you want going to the filtration beads, and the remaining fluid goes through the T and back to the reactor tank.

But given your explanation, it does not appear this idea will work and that a second ball valve is necessary.

I have attached a JPEG that has two control options that I am hoping you can chime in on. Option 1 is a facsimile of your set up. I understand from your response that a second ball valve will go after the first one, closer to the filtration tank. Does this mean that the two ball valves connect together with some hose in between? What am I missing here?

Option 2 is using a flow meter. You are right in that the link you sent me to Instrumart is a pricey one, but I have been able to find them much cheaper on-line. For example, there are a couple of Hedland units on Ebay right now. One is a 0 - 10 gpm meter for $12.99. I am thinking of buying that one but want to find out first if you think my option 2 drawing will work. If I understand correctly, I can just set the meter for the flow I want. For example, if I set the meter for 1 gpm, then 1 gpm will come out of the meter, and the other 4.5 gpm will just be pumped through the T back to the reactor tank.

Any further assistance you can provide would be greatly appreciated.

One final unrelated question: I ordered a 33 lb bag of Eco2Pure which should arrive in the next few days. I will be putting it in a 16 gallon water purification unit that I bought off my local Craigslist for $100. I emptied out the carbon and cleaned it out. However, the opening at the top of the tank is only about four inches, so I cannot get any type of mesh in there to elevate the Eco2Pure. As you know, these units work on gravity, so for the first batch at least, I will put 40 gallons in but will not get 40 gallons out. Some of the biodiesel, I am estimating 5 gallons or so, will remain in the tank, saturating the Eco2Pure. I emailed the Eco2Pure folks to ask if this is OK as the Eco2Pure will remain saturated in the solution between filtration cycles, and they said it should be OK. I know Eco2Pure is a new product, but I was just wondering if you had any input on this proposed set up.

Steve

Filtration_Control_Options.jpg (30 KB, 95 downloads) Flow rate control options

Hi Hummerman,
Without the valve on the return pipe you will not be able to get any fluid through the filter as the liquid will take the path of least resistance, and that's not through the filter if it has a wide open pipe. Here is a small writeup by GL for a pump throttle like what LE just described.
Jon

Nice graphic!


Figured I'd post it right in the thread for you..
-Graydon

Jon,

Thanks for the input and especially the attached writeup by GL. After I looked at the graphic the light went on in my head and I understand now what LE was trying to say. Should have been obvious, but hey, that is why I am on this site, to learn from others.

Graydon, thanks for posting my graphic, although I know now that neither option is really a workable configuration because both pictures are missing the return ball valve.

Steve

The second ball valve in my design serves the purpose of shutting the flow to the resin tanks without interupting the set flow rate of the other ball valve.
I use this tank to partially demeth the biodiesel prior to resin purification. I start with the transfer from the original settling tank where the glyerine stays behind by pumping from the StandPipe. I then open teh floor valve of teh seond settling tank/demething tank and allow the accumulated glyerine/soaps to mix with the incoming biodiesel and heat it to 160F or so while circulating it all together. This gets the residual methanol evaporating. I let this go for awhile before turning off teh heat and then switching from the floor drain flow to the standpipe flow and continue circualtion for an hour or so or until the BD has cooled considerably. I then will trun off the pump and let it all settle at least overnight.
Then it is ready to send through the resin by leaving the standpipe valve wide open but opening up the flow valve to the resin beds. The flow is then automatically controlled with the preset valve and after having the biodiesel ow through the lead and lag tanks I final filter using a CAT 2 micron fuel filter.

I cannot use a flow meter with my set up as my maximum flow rate is under the lowest setting for the meters, so I had to come up with a design that would do the job while not putting back pressure on my pump. I do have a small fan going over the pump to keep it from overheating.
The design works very well and didn't break the bank in the process.

Dies this get ALL the residual methanol out ? I'd be very surprised if it did, but what little is left does not in any way influence the cold flow properties of the biodiesel processed this way. I still get -6C before geling begins.

Traditional diesel fuel additives contain methyl alcohol in them so one would think that any residual methanol would affect the gel point or cloud point but not in my case, so how much if any remains ? I've not tested it to see, figuring the percentage is so low as to be a non issue. Of the several thousand litres processed and consumed using this method not one reported problem has surfaced in the many engines that burn it (B100 in 3+ cars, 4 tractors and one greenhouse boiler, and a B20 oil fired furnace).

The principle of heating and settling is based upon Graham Laming's GL design and adopting the principle that once methanol is removed from the biodiesel (absent of glycerine) then any residual glycerine/soaps will nolonger have anything available to keep them in suspension and they will fall out collecting on the floor of the demething tank. That this is happening is witnessed by the draining of glycerine/soaps from the floor drain after several batches being demethed this way. That there are no longer soaps present after resin is witnessed by my 2 micron CAT can not plugging at all this entire year whereas I was going through these like candy at a kid's party all the year previous due to soaps.

The samples I submitted for GC analysis of a flow right before resin and one right after showed that I had a pass before resin even started but got a 30% better rate after resin; from .240 to .161 for total glycerine.

HTH