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View Full Version : Mixing methoxide with a pump???


jejackson
07-30-2008, 02:58 PM
I have done a search, but the I did not find a good answer.

Does anyone mix with an air driven pump, like the one sold at UtahBD. I know there are some cheap versions of this type of pump out there, but does anyone know where?

Several of the processors on ebay etc. are mixing in a cone botton Poly tank with a small cheap blue air driven pump. Anyone got some info as to what type of pump this is and where to get one?

jejackson
07-30-2008, 02:58 PM
I have done a search, but the I did not find a good answer.

Does anyone mix with an air driven pump, like the one sold at UtahBD. I know there are some cheap versions of this type of pump out there, but does anyone know where?

Several of the processors on ebay etc. are mixing in a cone botton Poly tank with a small cheap blue air driven pump. Anyone got some info as to what type of pump this is and where to get one?

girl mark
07-30-2008, 05:43 PM
You can't ground a poly tank, so please don't use one with a pump for mixing methoxide. Pump mixing can cause static buildup. Realistically, we haven't had problems with this as fas as I know, but it seems like a really stupid idea when metal works just as well. Pump or stirrer mixed methoxide reactors work so well that you don't have to see into the reactor to know that the 'stuff' is all mixed, and metal is a lot safer and gives you more options for where to attach ports, sight tubes and sight glasses, etc.

I've messed around wth pump-mixed methoxide a little bit (I actually use a stirred system when not using passive carboy mixing) and I recommend reversing the location of where the pump input and output enters the tank (ie pump pulls from higher than where it dumps liquid into the tank) to prevent clogging of the pump with KOH or NaOH. Put the circulation line 'pickup' a foot above the level of where the KOH pile is likely to lie, and set up the pump 'return' line where the methoxide pumps into the tank, such that it points right at the pile or pumps up through it. That way you don't get KOH pieces into your pump, which may make some not-quite-compatible pump materials fail, and all you're circulating is dilute KOH-methanol mixture.

Suggestions for metal tanks:
beer kegs are stainless
old propane tanks
air compressor tanks turned on end
drums of various sizes

suggestions for getting lye into them:
2 12" or 3" pipe welded to the top as a port. You can also use a tank flange from mcmaster.com so as to have a female-thread port
large cam-lock fittings that allow you to easily open the 'port' but are fume-tight after you close them (such as a male adaptor and a 'cap' or a female adaptor and a plug). You don't need viton seals for these, viton is not methanol-resistant but Buna-N (nitrile) is, which is what's standard on these. Northern Tool has them cheap, as does Gopher INdustrial.

jejackson
07-30-2008, 06:42 PM
(Not being a jerk. I respect your knowledge)

How can mixing with a pump build up static charge? With an air powered pump the aggitation would not be much different than manual mixing in a carboy. These air driven diaphragm pumps can be turned down to very slow movement.

Is it the movement through the tubing that creates the static or the aggitation? Just curious.
I have a poly mixing tank already and don't plan on building a metal one, but I am intriqued by the added versatility.

Rick K
07-30-2008, 09:10 PM
I use an air pump and a poly tank that is in fact grounded to the electrical system via a wire that is screwed into the poly tank. I've used this method for over 2 years with no issues what so ever.

girl mark
07-30-2008, 09:25 PM
It's a well-known thing in methanol/gasoline safety, actually (it's one of the reasons that gas stations use gas hose with metal wire through it that grounds both the car/operator and the gas pump) . We ignore it when we use carboys that deliver methanol through plastic tubing, though. One of the reasons we ignore that issue is that the static buildup is related to flow rate through the plastic pipe, and gravity flow through carboys is generally very slow , similar to filling up your lawnmower from a gas can. It's still safer to not have ungrounded plastic in the system, but it;s less dangerous than rapid pumping used to mix methanol/lye.

Here's a brief summary of ways that static builds up in fuel storage/pumping situations:

http://www.purgit.com/static.html

and here are a few things from the report (summary)- they're talking about very rapid pumping of large volumes of flammables and sometimes of operations taking place inside of an explosive atmosphere inside of cargo tankers' partly empty tanks , so this isn't completely relevant, but you get some numbers on conductivity here:

"Hoses, wands, pipes, etc. Equipment introduced into cargo tanks for routine operations, most often, hoses, wands, and other piping components, has been blamed for several accidents. Static charge can accumulate on non-conducting material such as plastics or on insulated conducting material.

Polyvinyl chloride (PVC) wands used for overhead stripping of tank barges were blamed for a barge explosion which killed two men [12]. The plastic or polyethylene sleeves used for gas freeing can accumulate charge. Such a sleeve was partly to blame for the explosion on the AMERICAN EAGLE [10].

Fixed plastic pipe in cargo tanks has also been found to be potentially hazardous, since charge can build up outside the pipe during tank cleaning or inert gas operations or inside when fluid is flowing through the pipe [14]. "


"5.2.3 Non-accumulating piping wands, etc. Several accidents have focussed attention on the static accumulating properties of nonmetallic piping materials. The Coast Guard has recommended that all pipes, hoses, and fittings be conductive, electrically continuous, and bonded to ship's structure [19]. The following precautions have been adopted for stripping and cleaning "wands":

· Wands must be non-corrosive, nonmagnetic, non-sparking, and conductive. Dixie uses stainless steel wands.
· Aluminum wands with brass tips may be used. AWSC
· The Coast Guard has recommended against wands made of certain conductive materials such as aluminum -and magnesium since they can spark in contact with rusty hull steel.

Electrical continuity (bonding) of this equipment is critical; this is discussed in a subsequent portion of the report.

The recommended use of conductive materials for fixed piping also addresses this problem. The Coast Guard has specified that plastic pipes (such as post-chlorinated polyvinyl chloride (CPVC) ) in tanks containing combustible and flammable fluids have a maximum resistance to ground of 1 megohm (106 ohms). 200 kilohms is specified in tanks which are adjacent to pump rooms and which contain static accumulating cargoes (conductivity > 100 pS/m) [20].

The International Maritime Organization (IMO) is considering a similar standard: the resistance of plastic piping would not exceed 100 kilohms/meter, and nowhere should exceed 106 ohms [21]. "



Better info:

Here's another report on solvent safety, which covers a few things about static:
http://www.esig.org/uploads/documents/87-4-bpg4_final_def2.pdf

It really explains the hazards and where they come from well (ie pumping through components generates static, it can dissipate on it's own if given enough time, you can't ground plastic tanks under most conditions, the fire hazard is due to a combination of
-the possibility of having a static charge on the equipment and
-some way for it to be discharged in the form of a spark (such as the operator being at a different electrical potential and touching the equipment that had a static buildup)
-AND the presence of an explosive atmosphere so that the static discharge actually had something to set off, which is exactly what we normally avoid in a biodiesel 'plant' unless we've had a bad spill.

They do mention alcohol as a high-conductivity, which makes it safer to transport in plastic IBC's from a static perspective only. This may or may not be the same thing as 'it's safe to have ungrounded plastic mixing equipment'.

However, I have repeatedly heard from racing fuels suppliers that pumping of methanol can cause static to build up and that this can cause fires. It seems safer to not use it.

there are other issues with fire safety and flammable plastic containers.

Plastic carboys or other containers which have a one-time flow of methanol into the reactor are probably somewhat of a POSSIBLE hazard for static buildup, but from what I've read in a few reports, the buildup of static is directly related to fluid flow through the pipe- it's a concern if you're pumping too rapidly for what's called 'relaxation time' of the material, that is, the time it takes for the material to lose a static charge.


I think of gravity-fed passive-mixed carboys as a safety compromise similar to filling up a lawnmower on a hot day from a gas can full of gasoline, but I think that the slow gravity flow from a carboy through a piece of tubing doesn't create the same amount of static as rapid circulation through an ungrounded container.

I think we have exactly zero accidents in homebrewing that are caused by this whole issue, though.

There was one massive accident in commercial biodiesel that was attributed to static discharge, the fire that destroyed the Green Star Products biodiesel plant in Southern California a couple of years ago, but it's hard to tell if that's actually what happened since they had an IBC full of methanol fall off of a running (I think) forklift, and might have been just guessing at the cause of ignition.

producer
07-30-2008, 09:31 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by jejackson:

How can mixing with a pump build up static charge? </div></BLOCKQUOTE>


The friction caused by the liquid moving inside the pipes and pump housing can build a static charge just like walking across a wool rug on a dry day.

You know what happens next. You grab the door knob. ZAP!! A huge blue spark jumps from you to the knob. It generally kicks like hell.

Plastic piping and pumps do NOT conduct electricity. The electrical charge just keeps building and building until the voltage potential gets so great that the electrons jump to any grounded surface.

Metal piping and pumps conduct electricity. The electrical charge does not build up on the metal parts. It just quietly flows to ground.

Therefore, all tanks and piping should be bonded and grounded around methanol.

girl mark
07-30-2008, 09:32 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Rick K:
I use an air pump and a poly tank that is in fact grounded to the electrical system via a wire that is screwed into the poly tank. I've used this method for over 2 years with no issues what so ever. </div></BLOCKQUOTE>
How do you know it's actually grounded? I've heard that you have to have the metal ground rod buried deep into the liquid to actually conduct the static away.

Again, I think people have done lots of unsafe things with grounding of methoxide mixers and reactors and we don't really see accidents with it, mostly because to have an accident you have to have BOTH static discharge AND a big methanol spill AND a small enough space for the methanol spill to cause an explosive concentration of methanol vapor to oxygen at the same time. How many big methanol spills have you had during that time- probably none?

girl mark
07-30-2008, 09:53 PM
Here's another good 'static 101' article about flammables which discusses dropping a grounding rod all the way into your tank (grounding the frame of a plastic tank won't dissipate static, I've been told) :
http://www.fiberglasstankandpipe.com/handlingpetrol.htm

Like the other paper I referenced, they're concerned with splashing of liquid through the air , which gives my suggestion of 'reverse the pump flow in a pump-mixed methoxide mixer' another advantage I didn't know about.

Also, as described below: don't let your methanol vendor fill your methanol carboy while on your truck (I've been told by my methanol vendor and some of his customers that this causes lots of fires in the auto racing world, and that conversation happened while one of the vendor's employees attempted to fill my tanks exactly that way, with experienced racers in line behind me freaking out at the misbehavior. Again, not directly related to pump-mixed methoxide, just some info on static risks that's useful to know.)



"Single metal containers should be filled with metal spouts that are held in contact with the container or a funnel throughout the filling operation to prevent static accumulation and discharge. However, when transferring into or out of open top (i.e., not spout equipped) containers, the filling stream is broken and splashing occurs. In these operations (e. g., filling an open pail from a drum), a bonding wire should be used to connect the two containers.

Plastic containers are not conductive to a metal filling spout or funnel and can accumulate a static charge on the liquid surface. This may cause a discharge to the spout as the liquid level rises. When large plastic containers are filled, a grounding rod (i. e., connected to a bonding wire) should be inserted to the bottom of the container before filling. A recent survey documented 27 gasoline fires involving the filling of both metal and plastic containers on a plastic truck bed or carpeted car trunk. However, small plastic containers (e. g., one gallon) are less of a problem if the filling velocity is slow and the container is placed on the ground surface."

producer
07-30-2008, 10:17 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by girl mark:
. . . don't let your methanol vendor fill your methanol carboy while on your truck. . . . </div></BLOCKQUOTE>

Good advice. I have always removed my gas cans from my vehicle and set them on the ground when filling up at the local gas station.

Static electricity is a real danger.

UFO
07-30-2008, 10:22 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Rick K:
I use an air pump and a poly tank that is in fact grounded to the electrical system via a wire that is screwed into the poly tank. I've used this method for over 2 years with no issues what so ever. </div></BLOCKQUOTE>Poly tanks do not conduct, so you can put that wire anywhere you want, the tank will NOT be "grounded".

Raften
07-30-2008, 11:14 PM
Question, I have to transfer from a metal drum in the bed of my truck to smaller poly drums that I can lift out of the bed and onto the ground. Should I be grounding the drum to my truck while pumping with a poly hand pump?

UFO
07-31-2008, 12:32 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Raften:
Question, I have to transfer from a metal drum in the bed of my truck to smaller poly drums that I can lift out of the bed and onto the ground. Should I be grounding the drum to my truck while pumping with a poly hand pump? </div></BLOCKQUOTE>Yes, ground your metal drum to the truck and fill the poly drums in the bed. Seal them before you move them out.

Rick K
07-31-2008, 01:03 AM
Wow some great information here guys...

I had assumed incorrectly that I was grounded.

I guess the best thing for me to do is to put a rod that will contact the methoxide and that go to ground. I also have a metal fitting in the bottom of the poly tank that is grounded, that might be one reason I have not had an issue. The flow rate on my pump is actuall quite slow, less that 5 gallons per minute.

But now I have some concern because I am now going to be using a large diaphram pump and a larger tank.

Girl: Do you think if there were a rod as you mentioned inside the methoxide going to ground that would make my setup more safe?

brentsbg
07-31-2008, 02:51 PM
I want to build a methoxide mixer out of a 15 gallon poly cone bottom tank. The mixing would occur with a hand crank that would spin a propeller. Have the propeller so it actually pulls the liquid from the bottom so nothing builds up and stays there. I think it would work well and be rather quick. Any thoughts on this?

paulb3
07-31-2008, 09:32 PM
Sounds good to me as long as you are able to ground the mixer/drum while you are mixing it.

Big Mike
07-31-2008, 09:51 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by girl mark:

Suggestions for metal tanks:
beer kegs are stainless
</div></BLOCKQUOTE>

Beer Kegs are aluminum.

I thought they were stainless too, but I found otherwise when I had two made into a hot liquor tank and a mash lauder tun for home beer brewing.

(Haven' made any beer yet)

Mike...

UFO
07-31-2008, 10:31 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Big Mike:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by girl mark:

Suggestions for metal tanks:
beer kegs are stainless
</div></BLOCKQUOTE>

Beer Kegs are aluminum.

I thought they were stainless too, but I found otherwise when I had two made into a hot liquor tank and a mash lauder tun for home beer brewing.

(Haven' made any beer yet)

Mike... </div></BLOCKQUOTE>Some are, some aren't. Aluminum will give flavor to beer, so only the cheap stuff is probably packaged in it.

Donnie MacNeil
08-06-2008, 01:32 PM
Would grounding to the truck as suggested earlier provide the path to ground that you are trying to achieve? 4 rubber tires insulate the vehicle from the ground, unless your equipped with static straps.

Donnie

producer
08-06-2008, 02:11 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Donnie MacNeil:
Would grounding to the truck as suggested earlier provide the path to ground that you are trying to achieve? 4 rubber tires insulate the vehicle from the ground, unless your equipped with static straps.

Donnie </div></BLOCKQUOTE>

Bonding occurs when two containers are connected to each other with a conducting wire.

If you connected the fuel can in the bed of the truck to the metal truck bed, then you will have BONDED the can to the truck.

The truck would still need to be GROUNDED by connection to some external conductor that will transfer the electrons to ground.

canolafunola
08-06-2008, 03:05 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">and metal is a lot safer and gives you more options for where to attach ports, sight tubes and sight glasses, etc. </div></BLOCKQUOTE>

I have seen pics of poly bio processors melt down in a fire. If you use a metal tank, but have a sight tube of glass or clear PVC, the sight tube will melt or shatter in a fire and the contents will spill and feed the fire. What's the difference between a poly or metal processor if you have a sight tube that can fail?

producer
08-06-2008, 03:27 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by canolafunola:
. . . if you have a sight tube that can fail? </div></BLOCKQUOTE>

Keep the sight tube isolation valves closed when not in use.

You did install isolation valves, didn't you?

canolafunola
08-07-2008, 12:17 AM
I don't make bio. I suppose an isolation valve will help if you remember to shut it off. I think a temperature actuated isolation valve is better as you don't have to rely on your memory.