Plantoil/diesel conversion basics

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danalinscott

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Registered: 05/30/06
Posts: 924
Posted 08/21/07 at 10:13 AMReply with quote #1 

Here is my original design for the "WVO sucker". 


There are a LOT of variations that have been developed from this simple concept over the years.
Here are links to a few of them...


http://www.pauldrayton.com/uploadfiles/bd/wvosucker.php

http://www.biodieselcommunity.org/oilcollectiontank/

http://i81.photobucket.com/albums/j237/Murphy2000/P5230030copy.jpg



The Tutorial...

Well water pressure tanks (sometimes referred to as captive air pressure tanks) are what is recommended for use as the collection tank. This is mainly because they can often be obtained for free (or scrap value) from plumbers and domestic well drillers/installers in areas not served by a municipal water system. The ones made of steel are also lighter than most of the alternatives yet capable of holding a very high vacuum. Be aware that some fiberglass pressure tanks have been known to delaminate and implode under vacuum. An imploding tank is not dangerous but IS messy.  Nearly any other steel pressure tank will work but thin wall water heaters have been known to crush under vacuum as do common steel or plastic storage drums.

Here are some pictures of well water pressure tanks.

Steel tanks



Fiberglas tanks


The pressure tank is actually used to contain a high vacuum which will then be used to "suck" WVO into the tank. A vacuum can be created in the tank in several ways but the simplest is to draw as high a vacuum as possible in the tank while at "home" where 120vac (house current) is available. This will allow you to use a common refrigerator compressor to create a vacuum of around 27 "inches" (of Hg) in the tank and transport that vacuum to where the wvo is to be collected. A 30 gallon tank with a 27"Hg vacuum in it will draw in 10 gallons very quickly if a large enough hose is used (I like 1.5" "spa" or suction hose) the next 10 gallons will take about twice as long as the first since the vacuum is reduced to around 22"Hg and the lower the vacuum the slower the flow. Given enough time and low enough viscosity VO a 30 gallon tank will eventually fill to about 95%. There are ways to create vacuum while you drive or are collecting wvo as well. Ask if you want to know how.

The basic "wvo sucker" uses a common refrigerator compressor since similar to the well water pressure tank they can usually be found for free or scrap value at places the dispose of refrigerators. Please purchase your compressor from a business that collects and recycles the refrigerant since it is a very destructive gas to release to the atmosphere..and may cause lung damage if you breath it in while trying to remove a compressor from a refrigerator yourself. The same compressors used in refrigerators are also used in freezers, air conditioners, and dehumidifiers as well....so they are plentiful. The easiest way to find one is to call your local garbage collection service or recycling center and ask where you can dispose of an air conditioner or refrigerator. New refrigeration compressors are also sold by some appliance repair shops and occasionally on EBay. But of course the cost will be much higher than if you buy a recycled one.

Once you find a source of recycled compressors I suggest that you buy two. Used compressors may last for years but about 10% of them will seize up within a month. It is nice to have a spare handy if this happens...and you can usually get two for the price of one if you haggle just a little. Select two that have several inches of the inlet and outlet tubing still attached. The small plastic box on the left side of the compressor with the wiring is also important, it contains circuitry to start the pump.  Also make sure that the base still has all four little rubber feet on it. These are vibration isolators and without them the finished unit will make much more noise than it will if you have these.  They tend to drop out during transport..so be careful that you don't lose them on the trip home with your recycled compressors.

Normally there will be a cut 3 wire cord attached. Again select two which have at least a few inches of this cord remaining. It will make connecting a cord with a wall plug much easier.  You can also probably get a cord with three prong power plug thrown in for free here are well since every refrigerator has them.


Here is what refrigerator compressors look like.

And what they look like inside

They are very basic with a electric motor and either very simple (scroll or rotary) compressor inside the sealed outer shell.  Normally there will be several small diameter steel lines exiting that shell but only two will be the ones cut when the compressor was removed from the refrigerator. One of these will be the inlet and the other the outlet.

First you want to splice in the cord w/power plug to the (hopefully) three wires that are sticking out of the plastic electronics box on the compressor. Carefully cut and peel back some of the outer sheathing from the cord to expose the three wires with different colored sheathing inside. They should be the same three colors as the wires sticking out of the plastic electronics box on the compressor.  If they are not ask how to proceed in a post to this tutorial.

If this is the first wiring you have ever done...there are dangers which may exist due to doing it poorly...and you are accepting them all if you proceed on your own. If you have not done any wiring before have someone who has do it for you to be safe. If this is not an option use "wire nuts"   to connect the wires and tightly wrap the connections with several layers of electrical tape to make a lumpy but secure connection.    Once you are sure you have a good wiring connection plug in the power plug to a wall outlet and see if the compressor motor starts up. If it seems to just wiggle around and then "click" and quit unplug it from power and give it a few minutes to reset itself.  Sometimes a compressor that has been sitting empty and unused will get a bit stuck..but clear itself after running for a few minutes. So try at least 5 times if it seems to get a little closer to running smoothly each try. If this does not work try warming the entire compressor to around 70°F and trying the procedure again. If it still won;t run smoothly transfer the power cord to your other compressors and try again. You can usually return/trade back a seized compressor for another spare if you do so within a few days.


Once you have a smooth running compressor make a wooden base for it so you can keep it from "walking" around as it runs. To do this use a square of 3/4" to  2" thick board that is at least 2" wider and longer than the based of the compressor itself. Center the compressor on the board.  Place a washer on top of each rubber foot and then secure the compressor to the wood by running a screw through each of those washers through the foot and into the wood below. The head of the screw should be a little larger than the hole in the washers and the screw should extend into the wood by at least 5/8". If possible snug up the washer to the rubber foot just enough so the washer cannot move around and rattle.

You will probably notice that one of the steel pipes sticking out of the compressor  is spitting out little droplets of oil along with air pressure. Unless you want to add a few drops of light machine oil to the compressor every few hours of operations you will want to add a "re-oiler".   This is simple to make by taking a 1" section of small diameter (usually 1/4" or 5/16"id) rubber hose and sliding it over the end of the pipe that oil spits out of.  Now take a longer section (usually less than 1')  of flexible hose (I like clear hose for this) that has an i.d. that allows it to slip tightly over the 1" section already on the pipe and using a few heavy zip ties or a small hose clamp make that connection leak free. Find a few feet of heavy wire (like coat hanger wire) and drill two small (1/8") holes 1" apart in the wood base near the spot under the outlet pipe. Bend the wire in two and stick the free ends in the two holes. Then secure the 1' section of flexible hose to this wire support with a few zip ties so it points strait up. This will collect most of the oil escaping the compressor while it is running..and allow it to drain back into the compressor while it is idle. If no oil spits out of this pipe add a few drops of light machine oil until you can notice that it is spraying on the inside of the clear oil catcher tube while the compressor is running.  This oil catcher can also be modified to act as a check valve if your compressor allows air to leak backwards when the compressor is off. This may not be needed but just ask if it is and I will add that to the tutorial. This outlet will also be used to push the wvo you collect out of the tank using a small adapter that you add so a small poly line like the one describe later to supply vacuum to the tank.

Finally..we turn to the business end of the vacuum compressor...the remaining pipe sticking out of the compressor. Do not place you finger over this pipe to see if there is vacuum. If there is it can take a nice little "core sample" of flesh from your finger very quickly  if the pipe edge is sharp.  If air is exiting the compressor you can safely assume it is also being sucked in.

To connect the vacuum compressor to the "wvo sucker" tank  use a 3" section of rubber hose that tightly fits over the end of the inlet pipe on the compressor. This is the "connector" and will work surprisingly well for connecting a longer section of small diameter clear plastic poly pipe that is the same diameter as the compressor inlet pipe. This is usually available for under a dine a foot and can connect a tank that is up to 100' away very easily and inexpensively. make a second one and connect it to the compressor outlet so you can later also pressurize the tank just as you do the vacuum line. 

There are many ways to connect your vacuum pump to the vacuum tank. The simplest if you use a well water tank is to simply remove the guts from the shreader valve on top (it looks like a "tire valve") using a tire valve tool and then use short sections of rubber hose to adapt a small valve (either ball valve or needle valve) to fit onto the tube that is left when you "gut" the shreader valve.  Secure  that adapter and the valve with hose clamps and make another slip on adapter the same way for the poly tube vacuum line.   If you use another kind of tank (which doe snot have a schreader valve) you can drill a hole in the tank top and secure a small pipe stub in that hole with epoxy like JB weld or by having it brazed in.

Now you will need to purchase some hose that can take 27" Hg of vacuum without collapsing and a ball valve to fit it. This may be the most expensive part of your wvo sucker. I recommend not using hose smaller than 1" i.d. and (unless you have a very large tank) hose with over 1.5" i.d. will not save much time when filling. There are several type most of which have an inner and outer semi flexible liner with a wire spiral between. Some examples are:
http://www.pumpersupply.com/Hose/Standard_PVC.htm
http://www.pumpersupply.com/Hose/Clear_PVC.htm
and http://www.pumpersupply.com/Hose/Smooth_Rubber.htm

Buy enough suction hose to reach to your wvo collection containers from the truck or trailer that your tank will sit in.

Once you decide on a size of suction hose find a ball valve that will fit it. Be careful to not use a ball valve that has a hole through the "ball" part that is significantly smaller than your suction hose or this will negate the larger diameter hose. Now find a reinforced clear hose that fits the valve and add 4 to 5' of this to the ball valve side opposite the suction hose. This will be the "business end" of the sucker that slides into the wvo and through which it is sucked when you open the valve. I prefer having this hose clear enough that I can see any air or water that is passing through to help determine if the end is too high or low in the wvo collection drum/tank.

All that is left to do now is to create a place for the wvo to be sucked in and pushed out of the tank. The best way to do this is to either have a 1" to 2" (I like to use 1.5") pipe welded in so its interior opening is at the lowest point in the tank.  Some examples:

Often an exhaust shop can do this for you AND supply the pipe that fits your suction hose. If it is slightly larger or smaller than will fit tightly  they also have the equipment to stretch the end larger or smaller to fit tightly. Of course you will also need some large hose clamps to secure your suction and clear line to the tank and ball valve.

Almost ready to go get wvo now.
Only one more thing to do!

To create a vacuum in the tank simply start the vacuum compressor open the valve and slip the vacuum line onto the open valve end.  The refrigerator compressor does not create a full vacuum quickly and if you have a large tank may even overheat and shut down (while it cools off) on occasion. But after a while no more air will be exiting the compressor outlet tube and a full vacuum will be present in the tank.

With a fully evacuated tank you can now take it (in a truck or trailer..or trunk) to your wvo collections tanks/drums and unroll the suction hose till you reach it. Then slip the clear hose end about 6" below the surface of the wvo and slowly..SLOWLY open the ball valve all the way. If you open it too quickly it will tend to sink into the wvo as it gets suddenly heavier.  By collecting only the topmost oil you will avoid any free water or food chunks that may have settled to the bottom. Eventually this will accumulate enough that you may have to make a "crud run" and suck only from the bottom of your collection tanks/drums to get rid of this crud and water. If you are careful not to get much grease you can often dump this crud at a compost or RV (sewer) drain station for a very low fee.

Finally...when you get back home with a full tank of wvo first release any remaining vacuum by opening the small ball valve in the top of the tank. Then hook up your pressure line from the compressor outlet and (after placing the suction hose end in the tank or processor you want the wvo you just collected to drain into) open the large ball valve in the suction hose and turn on the compressor. As the pressure builds up in the tank the wvo will flow out faster and faster. Make sure the suction hose end is well secured since when the wvo is finally emptied from the tank the air pressure behind it will tend to make the hose fly around spraying the last of the wvo everywhere.

Please let me know if you have questions by posting in this tutorial discussion.

 
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Dana danalinscott@yahoo.com
Darwin

Registered: 12/25/07
Posts: 2
Posted 12/25/07 at 09:07 PMReply with quote #2 

The captive air tank I j found has two bullet holes in the bottom and side probably through the bladder thing. Is it still usable?
danalinscott

Moderator
Registered: 05/30/06
Posts: 924
Posted 12/26/07 at 12:49 PMReply with quote #3 
Quote:
Originally Posted by Darwin

The captive air tank I j found has two bullet holes in the bottom and side probably through the bladder thing. Is it still usable?

I don't see why not...if you can patch them.

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Dana danalinscott@yahoo.com
Darwin

Registered: 12/25/07
Posts: 2
Posted 12/26/07 at 02:01 PMReply with quote #4 
Right now it looks like the bladder is in the way. Do I need to cut a space in the bladder to make room for where the WVO will enter the tank and into the bladder? It doesn't look like I can remove the bladder through the 1.5 inch opening. the akward size of the tank, long and narrow, makes it so it would be hard to have a pipe modified and welded into the lowest part of the tank when it it laying on its side.
danalinscott

Moderator
Registered: 05/30/06
Posts: 924
Posted 12/26/07 at 02:55 PMReply with quote #5 

Quote:
Originally Posted by Darwin
Right now it looks like the bladder is in the way. Do I need to cut a space in the bladder to make room for where the WVO will enter the tank and into the bladder? It doesn't look like I can remove the bladder through the 1.5 inch opening. the akward size of the tank, long and narrow, makes it so it would be hard to have a pipe modified and welded into the lowest part of the tank when it it laying on its side.


You don't need to remove the bladder if you can cut or poke enough holes in it so wvo can pass through it easily.

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Dana danalinscott@yahoo.com
silica

Registered: 09/13/08
Posts: 2
Posted 09/13/08 at 10:15 PMReply with quote #6 
Hi,

Thanks for the plan. i am in the process of building this wvo sucker based on Dana's plan. i have the flotec well pressure tank and i have a brand new whirlpool refrigerator compressor 8201555 that i bought in ebay. it says it uses 134a refrigerant. i want to know if the new refrigerator compressors are pre-filled with the 134a refrigerant or not? this is brand new compressor, do i have to take it to the recycle place,  have them remove 134a?  i removed the black color cap on the suction pipe..i heard some hissing sound..as if some gas is coming out. i closed it immediately. any help is greatly appreciated. 
silica

Registered: 09/13/08
Posts: 2
Posted 09/14/08 at 01:16 AMReply with quote #7 
i am trying to find a correct NPT adapter for the schrader valve for my flotec pressure well tank, i couldn't find one. the standard 1/8 npt doesn't seem to fit. i was wondering how to connect compressor suction pipe with schrader valve. do i have to remove the schrader valve assembly completely and weld some other 1/8 NPT pipe adapter.
danalinscott

Moderator
Registered: 05/30/06
Posts: 924
Posted 09/16/08 at 07:29 PMReply with quote #8 
Quote:
i want to know if the new refrigerator compressors are pre-filled with the 134a refrigerant or not? this is brand new compressor, do i have to take it to the recycle place,  have them remove 134a?  i removed the black color cap on the suction pipe..i heard some hissing sound..as if some gas is coming out. i closed it immediately. any help is greatly appreciated. 


I can't say for sure but normally I do not think they come "pre-charged" with refrigerant.  If there was just a cap and no valve then I am  99% sure of this.

Quote:
the standard 1/8 npt doesn't seem to fit. i was wondering how to connect compressor suction pipe with schrader valve. do i have to remove the schrader valve assembly completely and weld some other 1/8 NPT pipe adapter.
 


IN some cases the valve can be removed completely and the port it was screwed into has NPT threads. In other cases the valve is permanently installed.  If you have the second case you can simply remove the "guts" of the Schreader valve (with a tire valve tool) and secure a small length of hose onto the valve end with a hose clamp or zip tie. Then you can secure a needle valve into the free end of that hose and add another short length of hose to the other side of that needle valve.  Now you can simply slip fit a length of cheap semi rigid plastic line(of very small diameter) into the free end of THAT line and using the same type of slip fit connection connect that plastic line to the inlet of the compressor unit (for creating a vacuum in the tank) or outlet (to pressurize it for emptying). 
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Dana danalinscott@yahoo.com
danalinscott

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Registered: 05/30/06
Posts: 924
Posted 02/10/10 at 12:29 AMReply with quote #9 
More images of these units....
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Dana danalinscott@yahoo.com
gyspyjake

Registered: 06/29/10
Posts: 5
Posted 07/19/10 at 11:55 PMReply with quote #10 
About how long does it take to pull a vaccum with a refrigerator compressor?
danalinscott

Moderator
Registered: 05/30/06
Posts: 924
Posted 07/20/10 at 08:32 AMReply with quote #11 
That depends how large your tank is.
An average refrigerator compressor should be able to create as much vacuum in a 30 gallon tank as it can in about 10-15 minutes.
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Dana danalinscott@yahoo.com
gyspyjake

Registered: 06/29/10
Posts: 5
Posted 08/05/10 at 02:39 PMReply with quote #12 
thanks for the answer. I was wondering what other types of tank would work for this. it is going in the back of my van and I only have 20" of depth and need 30 + gallons of sucker.
propane?
air compressor?
any complications with these?
thanks
danalinscott

Moderator
Registered: 05/30/06
Posts: 924
Posted 08/05/10 at 04:41 PMReply with quote #13 

Either will work though the compressor tank will be much lighter.


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Dana danalinscott@yahoo.com
WraunDog

Registered: 05/01/11
Posts: 7
Posted 05/06/11 at 01:53 PMReply with quote #14 
Hey there, this is my first post here.  I've been running veggie oil for about 2 years now.  This vacuum tank idea sounds great.  
I have a 30 gallon pressure tank with me.  I'm on vacation right now and collection is a bit of a problem, so I'm thinking that this vacuum tank idea would be the answer.  It'll probably suck 30 gallons up pretty quick eh?
I haven't had time to read through your posts completely yet so will keep the dumb questions to a minimum until I've done that but now that you're on to the subject of air compressors, I wonder if my air compressor, which is mounted on a 20 gal tank, could be used to create a vacuum in it's own tank and then suck up the oil.

Glad I found this site and you're post.  Thanks

Ron
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danalinscott

Moderator
Registered: 05/30/06
Posts: 924
Posted 05/06/11 at 05:13 PMReply with quote #15 
Quote:
I wonder if my air compressor, which is mounted on a 20 gal tank, could be used to create a vacuum in it's own tank and then suck up the oil.


I blieve it has been done but don't recall how to do it.
I DO recall it seemed a lot simpler to salvage a refrigertor compressor and use it to create a vaccum in the tank than modifying an air compressor though.

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