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flash evaporators how do I build one?
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Hi I have read and read and still dont ubderstant how to build one.
does any one has pictures?
also how to I build one?
 
Location: UK | Registered: March 03, 2011Reply With QuoteReport This Post
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There is a really long thread on the topic here.

It has pictures and detailed descriptions if you look for them

Rick
 
Location: Cowboy Country | Registered: December 06, 2004Reply With QuoteReport This Post
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I had a read but I could not find any picture of flash evaporator or how to make it and most of the links donnt open
 
Location: UK | Registered: March 03, 2011Reply With QuoteReport This Post
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I just checked the FE discussion and all the pictures I put up are still there, a quick count showed 35, you have to click the link at the bottom of the individual posts to see the pictures. I did not have a camera to begin with so the pics don't start til page 5 of the discussion, the early ones are pretty poor as they are frame grabs from video clips, the ones on the last couple pages are a bit better but not much.

The info needed to build a FE is basically there but there is no STEP1 - STEP 2 type instructions, there are MANY ways to build a FE out of what can be scrounged locally, basically you apply heat (250 to 350 deg f) and pressure (150 pounds) to the oil/water mix and squirt this hot liquid oil/water out of a tiny pinhole where the pressure drop flashes the superheated liquid water into steam so it separates from the still liquid hot oil.

there were a few pics of units others had built using various tanks and heater assemblies but I don't see them now.. (this is why I prefer to post the pics to THIS SITE rather than in some other website, they stay available here)

The discussions for the links that are now dead that refer to past discussions on this forum should mostly be found in the "archives" section of this website but it will take you some time to search them out, if the link went off this forum it probably really is dead if it does not work now.
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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Hi Tim,

Are you still using this equipment to dry your oil? The response to dinobio's same question on another forum indicated you may have moved on to something else. What gives?

Rick
 
Location: Cowboy Country | Registered: December 06, 2004Reply With QuoteReport This Post
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Originally posted by RickDaTech:
Hi Tim,

Are you still using this equipment to dry your oil? The response to dinobio's same question on another forum indicated you may have moved on to something else. What gives?

Rick

This is for demand the biodiesel before wash, to take all methanol off before wash in my dry wash.
 
Location: UK | Registered: March 03, 2011Reply With QuoteReport This Post



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dinobio,

There are no open source designs for flash evaporators specifically to remove methanol. When you get yours built and working properly, please share your designs with us. Don't forget to include step by step instructions and lots of pictures

Graham's Eco System Processor may be a vialable alternative to a flash evaporator. He has really good instructions on how to build a everything you need, and uses materials commonly found in the UK. Oh and lots of pictures.

Biopowered.co.uk is another good source of information for the UK biodiesel brewer.

If you need face to face training, the guys at vegetableoildiesel.co.uk are based in the UK and would be your best bet.


Rick
 
Location: Cowboy Country | Registered: December 06, 2004Reply With QuoteReport This Post
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Flash Evaporators, along with lots of other useful designs for the biodiesel brewer, can also be found in Chemical Engineering text books. Your nearest University Library would be a good place to start. In this Internet age, it's easy to forget the body of knowledge that still resides in print. All of the systems used by homebrewers and profesional manufacturers are described in those books, but don't expect step-by-step construction details. Think of them as sources of inspiration.
Cheers,
JohnO
 
Location: Moses Lake, WA, USA | Registered: August 15, 2001Reply With QuoteReport This Post
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dinobio - I never even considered using a FE to flash off alcohol, should work but alcohol vapor is just a bit more flammable than water vapor so be VERY VERY careful doing this, not sure weather it would be safer containing the flash-off inside a sealed tank or in some sort of an open setup that would still be able to collect the heated alcohol vapor, a sealed container sounds a lot like a bomb but maybe not, would be the same as a sealed pot still I guess, an open one would be a huge fire hazard. I don't think I would try it but if you do you do not need to run the temperature anywhere near as hot as is needed for water. I never looked up the vapor pressure tables for methanol to see how much pressure you need to keep it liquid at superheated (for alcohol) temps?

One possible problem I see using a FE for biodiesel is that if you run the temp too high you will also flash off a fair amount of the lighter biodiesel components along with the alcohol. I saw this a bit with my oil drying unit when ruining at 350 deg, I would get a constant drip of light oil out of the bottom of the vapor cooling dome that I was using to condense the water/oil vapor back to liquid so the oil vapor would not float all over the neighborhood, it would condense out on any cool surface, especially windshields, where it would cause oil-created "rainbows" the next time you used the wipers.

RickDaTech - I have stopped using the FE for a few reasons. To get totally dry oil in one pass I needed to run the temp up around the 350 deg f point but at this temperature you create a lot of polymerization on the inside surface of the heater pipe and the plumbing going to the orifice, bits of this plasticized material would break off and plug up the tiny orifice opening, I got tired of burning the begeses out of my fingers unscrewing and cleaning the hot pipe plug orifice. The polymerization goes away if you run the temp down around 250 deg f but you then have to recycle the oil through the unit several times to insure it is dry, either way it takes a good bit of electricity to do the extra heating, this was adding about $5.00 to the cost of each 50 gallon barrel of cleaned oil, the extra 10 cents/gallon is just something I would rather not have to pay.

Somewhere on the biodiesel side of the forum I read of a setup being used for drying biodiesel by injecting a high speed stream of the biodiesel back into the top of the open topped dryer tank such that the stream was directed directly down into the top of the biodiesel, this high speed stream draws a LOT of air with it by venturie action as the stream impacts and drives through the surface of the bulk fluid, the air then spreads out under the surface of the oil and rises as bubbles that break on the surface and release the water vapor. This required passing the oil through more than once but so did the FE when run at the lower temp. I heat my settling and filtering barrels to 100 deg f and re-circulate the oil continuously through the filters for 48-72 hours anyway so by adding some plumbing I was able to do this same "venturie" thing with the oil out of the last filter, this has worked fine for the last couple years even in the more humid Illinois weather, it works GREAT in the less than 10% Arizona humidity. I do have to change filters a bit more often than before adding the venturie to keep the flow through the filters high enough to produce a high speed stream out of the 1/4 inch hose barb that I have screwed onto the end of the 1/2 inch pipe plumbing. The 1/4 inch hose barb restriction has an internal diameter of 3/16 inch and works to increase the stream velocity high enough to draw plenty of air down under the surface of the oil. With the heated oil I can actually see the water vapor rising out of the top of the open topped barrel for the first several hours, or up to a day, after that enough water has been removed that the vapor is no longer visible, I just let the setup circulate the warm oil unattended for the total cleaning/drying period of 2-3 days, this eliminates the added electricity cost, and the burnt fingers, and I still end up with nice clean dry oil.
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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Thanks Tim,

On the biodiesel side, the most common way to dry oil seems to be heat and settle. But as you know, that doesn't get the oil dry enough to use as a fuel.

Drying wet biodiesel bone dry is a lot easier than drying oil bone dry.
 
Location: Cowboy Country | Registered: December 06, 2004Reply With QuoteReport This Post
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