Biopowered - vegetable oil and biodiesel forum
Biodiesel => Biodiesel equipment => Topic started by: Julian on July 27, 2013, 06:48:26 PM
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Is it necessary to have a domed or conical top to a processor and if so why?
Just pondering ideas for a new processor.
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I don't think it would be a problem to not have a domed top. I guess with a dome/cone any methanol condensation runs down the sides rather than drips, but so long as the takeoff faces down then surely not a problem.
Hey don't fancy my 500l steel vessel then Julian, that's domed? :)
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if the drum has a conical top on it, and you're sucking air out to de-meth, it'll stop it sucking in mist/drops of bio :-)
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I don't think it would be a problem to not have a domed top. I guess with a dome/cone any methanol condensation runs down the sides rather than drips, but so long as the takeoff faces down then surely not a problem.
Hey don't fancy my 500l steel vessel then Julian, that's domed? :)
Domed top just seems right ... perhaps guiding vapour towards the outlet don't know ... I was hoping someone would come up with a better reason.
My shed's only 6 foot square. That would just about fill it assuming it would fit through the door.
My quest for several years has been to go square, for the same reasons you highlighted recently.
I bought this over a year ago and it taking up valuable space in the garage.
(http://www.palmergroup.co.uk/Bio/Oil_tank.JPG)
Probably something like three years ago I bought a 400 ltr tank, probably very similar to the one you're using to destroy angle grinders. That too has been getting in the way, so I really need to get on and do something!
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Just had a thought ... we're doing exactly what they do when distilling whisky, so why are all stills this shape or similar?
(http://www.undiscoveredscotland.co.uk/usfeatures/maltwhisky/images/still17-450.jpg)
Something to do with the purity of the spirit?
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What I would add is that I'm currently using an inverted copper cylinder, and consequently that does not have a domed top. It has the vapour takeoff via a pipe that goes in through the side then up to the rim of the base. This works absolutely fine, so there is no reason why it wouldn't with a square vessel.
If you look at the GL push-pull design, he has (stainless?) wire wool in the vapour takeoff to collect any drops of vapour and drip them back into the vessel. For us this isn't really necessary.
My new processor, like KH, will be round, just because that seems right. But for me, that's all about the domed drain-off more than anything else, great for getting the glyc out.
Everything else will be square though, I'm so tired of drums wasting space. I have lots of vertical space so the steel tanks I've acquired are ideal, as they're nearly 600l but with a footprint of just 24 x 30 inches (tall and not wide!)
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Found this ...
Various shapes of stills are used and it is believed that the bulbs and boiling balls etc increase the copper contact at the right spots to produce better spirit. Some distillers use a purifier in the spirit still, which is a pipe reversing some distillate from the lyne arm back to the swan neck producing more reflux.
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What I would add is that I'm currently using an inverted copper cylinder, and consequently that does not have a domed top. It has the vapour takeoff via a pipe that goes in through the side then up to the rim of the base. This works absolutely fine, so there is no reason why it wouldn't with a square vessel.
If you look at the GL push-pull design, he has (stainless?) wire wool in the vapour takeoff to collect any drops of vapour and drip them back into the vessel. For us this isn't really necessary.
My new processor, like KH, will be round, just because that seems right. But for me, that's all about the domed drain-off more than anything else, great for getting the glyc out.
Everything else will be square though, I'm so tired of drums wasting space. I have lots of vertical space so the steel tanks I've acquired are ideal, as they're nearly 600l but with a footprint of just 24 x 30 inches (tall and not wide!)
I've come across the wire wool idea before. In the IG systems I used to work on, the scrubbing tower and deck water seal were fitted with knitted polypropylene demisters to minimise moisture carry over to the cargo tanks. Certainly in the company I worked for, no one seem to know if they ever worked ... we just told the customers that they did ... I always had my doubts though!
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i would say a dome top is the way to go this is just going on things i know and i have no proof if a flat top against a dome there would be a difference, it just seems right as its to do with heat and gases rising i feel a dome helps guide it out the center hole / sucking, a flat surface could create voided areas at a guess round the circumference say looking at the inside a 45 gallon drum.
i guess you dont have a flat throat entering a venturi it would hinder its useage / speed or action
i guess if the thruth be kniown a dome isnt as good as say the still aparatus above pics, it really needs like those a cone like a traffic cone shape or whiches hat shape or venturi throat for a more efficient flow taking all vapour all the time processing quickly...
but again i have no proof just an educated guess... i say cone. dome for ease of build though, flat i would try to avoid.
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I've done a little more reading and it looks like the acute cone and angled lyne, as they call it, are there to produce reflux. As the methanol isn't contaminated when I distill, then reflux isn't necessary.
I think there's merit in the idea of guiding the vapours towards the venturi suction, so on that basis a slightly coned top is probably preferable.
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My processor has a flat top and has never given me any problems but if I made another I would dome it as it seems a better solution as any vapour condensing on it would run back into the bio while on a flat surface it has to build up till it drips.
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That's a good point Dick, at least cones and domes prevent dripping.
If you bubble the bio in an open container afterwards (or if you water wash), I don't suppose it really matters as any remaining Meth will be removed anyway.
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The way I see it is a cone/dome added on the top increases the liquid volume/batch size,
this in it's self is why I added one to my 205 drum from the start.
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I'll be constructing the processor from scratch, so adding volume isn't really an issue, I can make it what ever size I choose ... haven't chosen yet though.
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hmmm what a good question?
what is the ultimate size?
;D
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hmmm what a good question?
what is the ultimate size?
;D
About 2" bigger than pressent.
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hmmm what a good question?
what is the ultimate size?
;D
About 2" bigger than pressent.
i will RAISE that 2" and add 1"
sorry thought we was playing cards again muhahahaaa