05-27-02 20:30
No 314844
The objective is to describe the construction of a multipurpose vessel that can act as both a reaction vessel - with cooling and heating capabilities and which can also act as a distillation setup with simple, vacuum and fractional arrangements.
Below is a graphic illustrating the draft idea.
For the main vessel a large 55 gallon stainless steal drum. The inside to be sanded and polished with an orbital polisher and compound. The top to be cut off and in its place a washer-like ring of stainless steel welded into place that has an internal diameter equal to that of the drum, and an external, several inches greater allowing for a ledge to which a top could be bolted into place. Holes drilled in for bolts.
For the top, a disk of stainless steal equal to the external diameter of the ledge, holes drilled to match the ledge. Two access holes are cut respectively allowing for over head stirring and the larger hole for a condenser or column depending on the setup. Additional bolt-holes drilled around these access holes. Appropriate gaskets to be put in place where necessary.
The condenser, column, connecting joints all to be fabricated from stainless steal parts and some tricky welding.
For cooling and heating of the vessel; An acetylene torch is passed across copper piping to white hot. After piping has cooled it is annealed (temper removed) to allow for forming. Piping is formed half-round and to be welded to the exterior and under part of the vessel in a coil network that would allow for adjusting. Adjustments would allow for where and how high along the outside of the vessel heat is applied (as heat is only needed to the height of the material being heated in the vessel for distillation). Glass insulation is provided around the coiling when heating. The coils are arranged into sections that intersect at in and out line manifolds. Circulating the heating and cooling fluids is a jet pump.
For cooling purposes a large tank of salted ice water could be arranged. Alternately for heating purposes, a 15 gallon stainless steal tank could be constructed to heat cooking oil by propane flame. A thermostat and flame controller could be coupled to the tank from a restaurant style gas powered deep fryer.
Questions:
Is the circulating oil heating scheme viable? Using the coils for circulating cooling fluid is highly desirable. If a sole direct flame heating is desirable - could the heated oil be circulated and additionally - direct flame could be applied under the vessel under the bottom coils? Its the purpose of oil heating to allow for smooth, even heating.
For the over head stirring motor, it is desirable to be able to stir during a vacuumated distillation - does anyone know of a device that would allow for throughput shaft into a highly vacuumated system? This sealed device should also be used when refluxing flammable liquids.
(Moderator)
05-27-02 22:06
No 314876
Some of your ideas are good, but a mere drum isn't going to hold much vacuum
For starters, you might want to study alcohol fuel production, literature should be available in a local libary 
Once you understand that, you'll be more ready for more advanced construction projects
(Hive Bee)
05-27-02 22:39
No 314888
Lugh: Thanks for the post.
but a mere drum isn't going to hold much vacuum
Do you mean it cant maintain a vacuum or physically cant support a vacuum? Appropriate gaskets would be used and the bolts would be of a heavy gauge and could be tightened considerably with long wrenches. Additionally id guess that all seams could be greased over to assure a seal. If the structure couldn't support a high vacuum - well, one that could would be used.
For starters, you might want to study alcohol fuel production, literature should be available in a local library
With intention for starting some informative discussion in this thread can you expand on this? What aspect of fuel production would be helpful to look at when considering a project like this?
(Hive Bee)
05-27-02 22:51
No 314891
Hammer: Ideally this setup would function to distill product oils, that is to say a vacuum of 1 micron(mm/hg) would be lovly.
For a application of this size though, a simple water aspriator or even a nice Welch 1200 vacuum pump wouldnt cut it. Although what vacuum source would fit this monster is for another thread entierly.
My only reservation about using thicker steal in the construction is that the heat transfer would be depleated. This could be solved by using more direct means of heating though.
(Hive Addict)
05-27-02 23:18
No 314901
why are the heating coils on the outside? wouldn't it be better to have them on the inside, and keep the manifolds on the outside? this would require them to be SS, of course.
another idea would be to have a separate set of coils for cooling liquid.
i learned a thing or two from charlie dontcha know.
(Hive Bee)
05-28-02 00:35
No 314931
RoundBottom: That's a great idea to have the coils on the inside! That would certainly solve the heat transfer problem if thicker steal was chosen for the construction material. Is that the a more valid option for heating and cooling?
Affixing total covering coiling to the outside would be a far easier task than doing the same on the inside and it would provide heat/cooling to every surface- however it would be less efficient as its indirect.
It would be difficult to have the entire vessel coiled on the inside - opposite my diagram. However you may not need to weld the coiling to the inner surface as its a direct means of heating/cooling, and simply have the outside of the vessel insulated.
If the coiling was kept on the outside, and additionally a run of coiling was placed inside and the entier vessel was insulated this may perhaps provide a good cooling and heating setup?
What would be the benefits of having coils on the inside and outside? Is there some other heating/cooling scheme that would work?
(Hive Addict)
05-28-02 00:52
No 314938
(Rated as: excellent)
as in ss tubings within the vessel itself are the standard in the industry. KIckass work Alchemy, still absorbing it...
If you can find one, an industrial steam kettle, used in hospitals and military institutions would be something adaptable, though It might not suit this need. I hear Colonel Sanders even deep fries under pressure, those things mentioned just to muse the old designer bent. Nice to see here, very nice.
Instant Karma's gonna get you, gonna knock ya right in the head
(Line Monitor)
05-28-02 02:06
No 314961
Someone knowing i'm a collecter of relics gave me a comercial size pool filter. It's about 1/4" thick S/S with a dommed top convex bottem. The top has a bolted flang. It also is tapped with a PSI gage and some plugs. How would copper tubing bee?
Give me libreum or give me Meth
(Hive Bee)
05-28-02 02:13
No 314968
Just go around to the local ag/dairy/food processing plants in your area and ask if they have any "scrap" stainless or surplus stuff they can liquidate...talk to the yard guy to get you to the foreman to get you to the plant engineer...they always have shit they'd be glad to have you haul away for them.. afof got a complete 30 foot distillation and another reverse osmosis membrane set up for free!
Infinite Radiant Light - THKRA
(Hive Bee)
05-28-02 02:18
No 314971
A used steam kettel might be somthing to consider, what the heck are they and how/what are they used for? They sure lookin interesting!
What is their basic contruction? How would they stand up to high vacuum?
(Hive Bee)
05-28-02 02:28
No 314979
what the heck are they and how/what are they used for? They sure lookin interesting!
________________________________________
Looks like you have found a setup for brewing beer, like the ones used at micro-brewerys. There's a couple of nice ones around here where you can get a good dinner and ripped off of the brew of the week. Oh yeah
Meth, it does a body good
(PVC-Analog Taste-Tester)
05-28-02 15:39
No 315180
What could be used as an inert coating for the inside of the vessel? I can't find anything useful as far as teflon mixures goes, but what about pottery glaze? If it can stand-up to the heat of a kiln, then it'll work fine in any type of chemistry "experiment". I was thinking about making a 5000ml flask from a piece of steel pipe with a huge diameter, sand the inside, then apply the glaze. After the glaze dries, heat the outside of the vessel with something like a propane torch to cure the glaze.....But, the steel might expand too much and shatter the glaze. Ahhhh, fuck it, I wanna learn glass blowing.
Love my country, fear my government.
(Hive Bee)
05-28-02 17:29
No 315212
Bwiti: You definitely cannot glaze the inside of a metal container with pottery glaze. The expansion rate is to different. Additionaly you can't cure pottery glaze with a torch either - a proper kiln has different settings depending on the glaze that is used (red roka, roqu, etc.) and must cool down gradually.
You can however enamel some metals with glass powder. This is done in jewelry making usually on metals that have resistance to oxidation at high temps. Usually on silver, sometimes on copper - even gold, a holding agent is spread on the piece, and glass power is dusted on, the piece is then placed into a furnace at around 1500f until glowing hot and when the molten glass is smooth over the piece. At this temp the holding agent which also acts as an anti-oxidizer burns off and the glass is enameled onto the surface of the metal.
I think you might also reconsider teflon. There are many grades of "Teflon" which is a brand name for a line of coatings produced by DuPont, anyways, in this product line there are like 5 or 6 different formulas with different properties; FEP, PFA, PTFE etc. and are ideal for coating metal and have superb heat and chemical resistance depending on the formula. 3M also manufactures a big line of coatings, off hand Kel-F (PolyChloroTriFluoroEthylene) offers good acid resisitance.
Just a suggesting - if you look up custom "teflon(or whatever) coating" on the internet there are places that will do just that. Its kinda pricey but they will coat anything ya want. SWIM had a pressure tank for car painting ghetto rigged into a pressure reaction vessle coated with teflon, works like a charm.
(Hive Bee)
05-28-02 23:19
No 315307
If 5/32" - 6/32" plate steal was used for the body would there still be need for suport bars or consern over vacuum? I took a stack of computer paper and measured this thickness out just for a visual que. Im working on a revised draft, but im considering that even with steal this thick, a combination of hot-oil/coil heating and direct heating may work.
Also im considering using other metals that conduct heat well for the contruction material - namly copper. Would copper be a more expensive material to work with? Obviously if copper is used the interior would be coated with teflon or like material...
(Title on BackOrder)
05-29-02 00:52
No 315334
as far as a heating source, you can modify a turkey cooker to heat a kettle fairly easily. I've seen a few modern day liquor stills set up utilizing this design.
as far as getting the container to distribute heat evenly, you will probably want to get the tank modified to have coiled tubing running through it that you can run hot oil through. Thick copper tubing would probably work the best.
(Hive Bee)
05-29-02 02:47
No 315382
Regarding vacuume source. Theoretically, in a sealed system, high flow is not required. Once a vacuume has been established, distillation and condensation being equal, what is to be evacuated? In practice, of course, all systems leak and condensation is never perfect. But, your vacuume pump might not need to be as robust as you imagine.
Lugh, is correct, regarding the original drum idea. A 55 gallon drum is not likely to survive even a moderate vacuume. Unless, drums are alot stronger than they used to be; a simple aspirator, at normal temps, can collapse a 55 gallon drum, if given a little time.
(Distinctive Doe)
05-29-02 04:11
No 315427
A used autoclave might bee ideal.
Not sure what modifications would bee necessary for vacuume work.
Those who give up essential liberties for temporary safety deserve neither liberty nor safety
(Hive Bee)
05-29-02 04:40
No 315443
When cooling a vessel of this size, coils have excellent cooling ability as water can be circulated through them very rapidly. A jet pump is desirable for this application.
It is known that as the volume of the material increases, exponentially does the amount of energy needed to bring it to a boil.
In a nearby 15 gallon steel tank (or steam kettle as suggested), oil could be easily heated to 100c-400c from a direct propane flame and circulated rapidly. I believe with some modification a jet pump could be used to circulate the hot oil as well.
In put is needed here; I do not have any experience to draw from when inferring the best heating method. It has been suggested that direct flame heating is needed for something this big. Considering how well forced hot water heats my house, it would be very convenient to use the coiling aforementioned for heating purposes as well. It would also be very easy to integrate a propane burner under the vessel for additional heating.
With a sizable burner under the vessel optimum heating could be achieved, additionally the circulation of hot oil around the vessel would allow for smooth even heating and with insulation material around the entire device - I would think that heating to reflux would be easily obtained.
Below is a graphic illustrating a revised draft incorporating elements suggested in this thread.
Please note i left out the coils in the lower graphic and abridged the coils in the top one simply for easy of drawing, the intended exterior coil configuration is shown in the first post.
The reason for keeping the main coiling on the outside is simply because it would be to difficult to form and affix it to the inside. I think the bottom plate - which has interior coiling and a burner, is the main source of heating/cooling, and the bulk of the exterior coiling just supplies additional heating and cooling value.
Im considering two variations for the bottom - the lower one incorporates a sealed air chamber. You often find air chambers in high end cookware - i think somthing like this would help heat distribution greatly and avoid hot spots if flame heating is to be used. With this scheme there is also heating protection allotted from the copper coiling that is encased in the chamber, this to help absorb and distribute heat into the vessel.
(Distinctive Doe)
05-29-02 19:38
No 315656
the ideal is to heat with high pressure steam,
Do to the thermodynamics of condenseing steam you ca put ALOT more heat into the vessel with it.
Those who give up essential liberties for temporary safety deserve neither liberty nor safety
(Title on BackOrder)
05-29-02 23:42
No 315744
What about a steam jenny, the steam pressure washer devices? They can be had for around $1,000. I've seen a person with 3rd degree burns from one of these devices that malfunctioned on him, so I'm not saying their safe.
is 100C going to be hot enough for your applications? I doubt it will. Oil is probably your best bet if your planning on going homemade.
What are you planning on reacting in this anyway?
(Hive Bee)
05-30-02 00:23
No 315755
goiterjoe: i suspect with the proper equipment steam could be used to heat the contents far above 100, as we know liquid water at ambient pressure will only be 100c, but steam can get far hotter.
As per the usage; its actual intended use is as an alien pod incubation chamber, but im sure it could be used for any type of chemical reaction, and given all its purposed features could also handle subsequent product extraction, seperation and distillation.
(Title on BackOrder)
05-30-02 00:38
No 315757
I was just wondering if you had considered using disposable reaction containers. For example, you could run a Al/Hg reductive amination in an aluminum trash can stacked inside a plastic trashcan. That's if you're looking to reductively aminate something. Or, if you were thinking about running a huge volume oxone reaction, maybe using that same plastic trashcan. Then you could just purchase a 5 liter distillation setup for your distillations. That's if you're planning on making a pod baby that requires reactions along those lines.
I remember this one time I tried to make a pod baby. I was drinking late one night when I noticed these strange lights coming from behind the barn. I went out to see what it was, and saw this huge spaceship. Beside it was the green alien girl stirring this huge kettle with an oar. After getting over my initial shock, I asked her what she was doing. she told me that she was making a baby. In my drunken stupor, I told her that she was on earth and that's not how babies are made. She looked at me with a confused expression on her face, and then asked if I could show her how babies are made on Earth. I proceeded to take her inside the spaceship and fuck her brains out. After about 25 minutes, I rolled over and told her I couldn't go again for another hour.
She looked at me funny, and said "So where's the baby?"
I said "Oh, that takes 9 months."
"So, why'd you stop stirring?"
(Hive Bee)
05-31-02 23:23
No 316416
Who does this kind of custom metal fabrication and how does one approach them? On construction what type of welding should be used?
(Hive Bee)
06-01-02 02:09
No 316466
How would one approach a custom fabricator? I don't have any need for something like a 50 gal. reactor/distiller, but I could use a solid steel block with about 100 holes in it, with two other blocks with steel pegs fitting into the holes in the first block perfectly. I could even use some custon raised engraving on the ends of one set of pegs. But this would be a little obvious to some people, so how would SWIM approach a metal fabricator about such a job?
And as for the 50 gal bohemouth, I don't really think that you would need anything like that unless you were doing something like a 25-50 leukart. Other than that, I can't think of any reaction that you could do that couldn't be done in a disposable container. Large scale oxone runs, as well as performic runs, could be done in a 5 gal PP drum. You can buy them used, and throw them away when you're done, or you can start a collection of them. The cyano, boro, and Al/Hg can be done in them with no prob. If it's the Al/Hg, then when you extract, you can use toluene, pour the toluene off the top, and just leave the nasty Hg waste in the drum. Clean, easy, and you can store these away 'till you got about 10-15, then throw 'em in the back of a pickup(covered up of course), and leave 'em at the nearest hazardous chemical disposal in the middle of the night. Maybe even a little note about the evils of the drug war. And as for distilling, I would just get a 5L distilling setup. If you have to reload it a couple of times, booooohooooooo! Have a little patience!
Do not go gentle into that good night. Rage, Rage, against the dying of the light. --Dylan Thomas
(Hive Bee)
06-01-02 02:21
No 316473
Who does this kind of custom metal fabrication and how does one approach them? On construction what type of welding should be used?
(Hive Addict)
06-01-02 03:54
No 316516
> 5 gal PP drum
what is a PP drum? a portable urinal or something
?i learned a thing or two from charlie dontcha know.
(Hive Bee)
06-01-02 05:24
No 316549
PolyPropylene which is a common plasic used for all sorts of things. it has resonable chem resistance. you'll also see PE polyethylene used alot.
(Hive Bee)
06-02-02 02:27
No 316781
On construction of the stainless steel condenser and fractionating column.
Construction of the condenser and column would be pretty easy. Two lengths of piping are selected, one longer than the other to allow for a drip lip. And two disks of SS larger than the diameter of the wider pipe are cut with appropriate access and bolt holes. The parts are put together as shown.
The basic construction of Condenser and Column are essentially the same. After the main parts are assembled and welded together holes are drilled into the outer pipe and a small length of copper pipe is welded into place over the hole. Two holes for the condenser for water to be circulated, and one for the column where a vacuum pump can be attached and the interior shell chamber can be vacuumated and the access pipe can be crimped and sealed.
Input is needed here, for gasket material I drew in a hand cut sheet of Teflon that would fit between the lid of the vessel and the connecting plate of the condenser (or column). What would have to be done to make these connecting joints as vacuum tight as possible? I think: a gasket of appropriate material (any suggestions?) that is greased with high quality Apiezon Vacuum grease or something similar, along with heavy gauge bolts that would be tightened with considerable force would be enough?
(Title on BackOrder)
06-02-02 03:10
No 316786
For your fractionating column, how about making it using two pieces of pipe, one that fits snugly inside the other, and about 10 washers that fit snugly inside the larger diameter pipe? you can take the small pipe and cut it into 2.5" lengths, and then stack them in the larger pipe, alternating pipe, washer, pipe, washer, etc. To make the washers drip properly, you canpress them into a convex shape before you slide them in. Once you have a column of your desired length, weld the inside pipes firmly in place.
As far as the gasket goes, teflon isn't going to give you the amount of compression you are going to need. I would say buy a sheet of 5/16" rubber gasket material and cut out several O-rings. Replace them periodically. Also, make sure to tighten your bolts down in a criss-cross pattern, or else you will never get a good seal.
Ideally, to get the best seal, one that will seal tighter when you apply vacuum, would be to use a countersunk design like so:
column
| |
| |
\ /
.\ /
to flask:
| |
|\ /|
| \ / |_____
(Master Searcher)
06-02-02 03:16
No 316787
HVAC/refrigeration stores have gasket material and different size gaskets.
http://www.geocities.com/dritte123/PSPF.
The hardest thing to explain is the obvious
(Hive Bee)
06-02-02 03:28
No 316790
goiterjoe: If there is a vacuum jacket around the column it will be a lot more effiecient. It would probably be best to weld a peice of heavy gauge SS screen over the bottom hole so that you could fill the column up with whatever packing material is best. Which brings me to my next question, what packing material would be best for somthing this size?
As for your compression gasket i think it might be to difficult to machine that type of shape into somthing that is being made from skratch, i agree teflon probably isnt the way to go. If a greased rubber gasket was used, same size and shape as the one drawn in, perhaps if the inner hole of the gasket was smaller that the access hole in the lid then it would be forced down into the vessle when the drip tip was pushed into place - fitting snuggly between the drip tip and the side walls of the access hole. And of course the bolts are still to be tighted as much as possible.
(Title on BackOrder)
06-02-02 10:00
No 316816
Taking an undyed ceramic coffee mug and breaking it into small pieces should work well for packing your column.
(Hive Bee)
06-02-02 23:40
No 316916
that metal of any sort would not be the best material to make a fractionating column out of. Metals have too low of specific heats, there would be too much lost heat. I would consider a ceramic one, or some kind of high-temp plastic. But ceramics do have unusally high specific heats.
Do not go gentle into that good night. Rage, Rage, against the dying of the light. --Dylan Thomas
(Distinctive Doe)
06-03-02 01:26
No 316944
you can order rachig rings online
Those who give up essential liberties for temporary safety deserve neither liberty nor safety
(Hive Bee)
06-03-02 06:09
No 317048
Regarding the fractionating column, can someone suggest the best implementation of a ceramic column while still holding to the design requirements?
As shown for the column, two stainless steel pipes are fitted together and welded between two connecting plates and the area around the inner pipe is to be vacuumated for optimum insulation.
The vacuumated shell is desirable and, since the construction of the column will be solely of stainless steal, easy to implement also.
I agree ceramic would be the best material but if the construction of the column will be totally of stainless steal, im not sure if it would be best to integrate a ceramic pipe into it.
Construction wise there would still have to be two pipes - each welded to two connecting plates to facilitate vacuum tight connecting. I think the obvious route would be to have an inner SS pipe with a diameter selected to allow for the fitting of a ceramic column insert.
My main concern for the ceramic column is in the construction. There would be no practical way to make a seal around the ceramic column to seal the main vessel from the area between the outer wall of the ceramic pipe and the inner walls of the inner steel shaft. The natural flow of vapor would be from the hot vessel to mainly the condenser, but also to the walls of the inner steel pipe reducing efficiency. This might not pose much mechanical problem for the distillation and I do counter this argument completely further down.
Input is REALLY needed here. It may be that metal is an acceptable material. Im considering that the inner tube could be of particularly thin metal since the shell around the inner pipe is to be highly vacuumated, the force exerted on the inner pipe would be stabilizing - pulling out in all directions, and not inward (opposite crushing a can by vacuumating it idea). The vacuum in the shell would be perfect, and any vacuum obtained in the main still would likely be less - again that thin metal can be used.
Since it will have a vacuumated jacket I dont suppose the small amount of conducted heat loss between the wall of the inner pipe and the connecting plates would be degrade the efficiency of the fractionating column. It may very well be that the dynamics of a large still like this cant be compared to this, but I would argue against a regular vacuum jacketed glass column. Additionally if this is the case even partially, would there be a considerable enough gain in efficiency to warrant a ceramic column at all?
(Hive Bee)
06-03-02 20:08
No 317212
raching rings AKA raschig rings are the way to go, they are used for home distillation of alcohol and can be gotten at places selling supplies for the such:
(Hive Bee)
06-04-02 00:08
No 317254
I guess you could have a ceramic shop make a ceramic pipe with a little flang at the bottom and top, leaving enough room from the outside of the pipe to the screw holes to fit a SS pipe with a smaller flang over it to fit on the same screw holes. You could use a teflon gasket for the flang, and rubber washers around the screws. Just don't get too excited when you're screwin' it down.
Then you could pull the vacuum from the SS pipe, and you're off. Make sure the ceramic pipe is flanged on both ends, of course, so you can attach the condensor.I don't guess you'd absolutely HAVE to make it ceramic, but if you want to go all out, that's the best way I can think of.
Do not go gentle into that good night. Rage, Rage, against the dying of the light. --Dylan Thomas
(Hive Bee)
06-05-02 18:11
No 317864
Hmmmm this is all sounding a bit familiar. Wasn't it KRZ who was experimenting with Kegs a few years back? Seems like a keg would be a good starting point for your vessel, they're designed to hold a good bit more pressure than a drum. Now as to approaching someone to custom construct something like this my suggestion would be to find a chap building custom motorcycles. There are a couple of cats in Ceps town and they are very talented. They're also used to working with SS, building exhaust etc. Watch one of these bradda beat a gas tank out of two sheet of steal on a shot bag and you'll have a healthy appreciation for the art. If you find a talented bike builder they'll be able to build just about anything you design. Not to mention they're likely not to ask as many "questions".
Bwiti ceramic on ss doesn't sound doable. Wonder how epoxy would work. There are a few epoxy prods used for lining fuel tanks. Very easy to use, and have excellent chemical resistance. Not sure how they'd hold up to heat but something to consider. Cheaper and easier than blowing glass.
"No I'll tell you what insanity is, insanity is majority rules"
(Title on BackOrder)
06-06-02 01:37
No 318009
Kegs are only designed to hold pressure on the inside pushing out. They would crumple just as fast as a drum if vacuum is applied to the outside of them forcing in.
(Hive Bee)
06-06-02 01:46
No 318016
bicepules: Thanks for the post. The best suggestion that has been made to be thus far is to look in a big city phone book for the boiler makers union and contact a few member shops. This union is a large group of master metal workers who's work base is generally all custom, they work with many different materials and union shops are typically the best equipped.
It would be easy to approach a place like this with an explanation of the vessel as a cooling tank of some sort, an alcohol still - or anything creative.
Your epoxy idea sounds doable, obviously if its used in gas tanks it has excellent solvent resistance - something to look into.
I have been considering the ceramic idea more. If a ceramic pipe could be easily gotten it might be something that could be implemented correctly.
If the column section was designed so that the ceramic pipe was removable from the top (for cleaning), and sat on a ledge created by the hole of the lower access plate that had a smaller diameter than the inner SS pipe, you could use some simple gaskets to seal the inner SS pipe walls from the system. The gaskets would not have to be air tight as the whole inner system would be vacuumated, but just in place to keep the vapor flow on the inside of the ceramic pipe. However I still question if anything is even needed.
(Hive Bee)
06-06-02 05:16
No 318088
Yeah, a ceramic pipe wouldn't be an absolute necessity. I'm sure that two SS pipes with a vacuum jacket between them would surely suffice.
Do not go gentle into that good night. Rage, Rage, against the dying of the light. --Dylan Thomas
(Newbee)
06-07-02 00:41
No 318363
quite how you get 30 psi vacuum (pressure differential that occurs for example when outside is 2 bar and inside is 0 bar)but say that you did then the top flat is going to be under a lot of pressure, look at industrial reactors they don't use flat tops for anything more than 1-5 psi differential otherwise the top becomes extremely heavy we're talking 15mm thickness or even more for a 1m dia at 5psi the load on the top is something like 2 1/2 tonnes.
a better still on a smaller scale can be created from a keg, the biggest kegs around here are 90 litres plus.
kegs are guaranteed to withstand 40-60psi internal therefore a differential of up to 25-45 psi is reasonable.
(Hive Bee)
06-07-02 00:42
No 318364
Alright, moving on, i think ill bring this up now, what kinda of vacuum source would be needed to vacuumate something this big to a degree where product oils could be distilled effectivly?
(Newbee)
06-07-02 00:50
No 318366
steam ejectors are used industrially, i think these use hp steam in a venturi to pull a vacuum theyre good for 5 psi vac and anything up to thousands of litres a minute i guess a search on the patent site should throw up some designs. a normal vaccuum pump would be a complete waste of time its capacity would be overwhelmed by volatiles and leaks
(Hive Bee)
06-07-02 02:58
No 318403
I did some searching online and also Lugh provided some good direction to sources of steam driven aspirator setups. I think that somthing that eleborate would be over kill for a setup this small (or large) considering that industrial steam powered aspirators can be 20 feet long or more. http://www.gea-jetpumps.de/produkt/vakuu
Could a heavy duty direct drive vacuum pump be used for a setup like this?
Check out that last mofo, god damn the fucker weighs more than me!
(Hive Bee)
06-07-02 08:17
No 318477
obia: You absolutly correct. I tried to calculate the stress that would be placed on the vessel under vacuum. Considering dimensions of the vessel to be that of a standard 55 drum, 24"x 34" the total surface area would be about 3467 cubic inchs. Given standard pressure at 15 psi, across the whole vessel that would mean a total of:
52,005 lbs of force if a perfect vacuum was obtained
50,664 lbs @ 20mm/Hg (safrole boils at 120)
48,652 lbs @ 50mm/Hg (safrole boils at 140)
45,971 lbs @ 90mm/Hg (safrole boils at 160)
(Stoni's sexual toy)
06-07-02 11:12
No 318523
As I stated in another thread on the newbee board lately you will experience big headaches when vacuum distilling oils with 6L flasks. I can barely imagine the amount of bumping you will experience in a 200L barrel. You need some extremely good stirring and capillaries to introduce small gas bubbles into your hot mixture to achieve a somewhat consistent boiling. This also means you need a big ass vacuum pump due to the intentional leaks you have to introduce.
There is a reason why the industry tries to avoid normal distillation of high boiling stuff like the plague. They prefer crystallisation for purification whenever it's possible.
Besides, it makes no sense to process such big amounts. A continuously running conventionally sized glass-made still can produce several liters of distilled precursor or product every day. And they don't need much attention.
You are not the first bee dreaming of becoming the local Escobar of the Ecstasy trade. Everyone lives through such dreams of grandeur at the beginning of their career. Don't do it.
I'm not fat just horizontally disproportionate.
(Hive Bee)
06-08-02 01:14
No 318669
What would be the largest you could go for the setup described and still have it be pracatically fuctional?
There is a reason why the industry tries to avoid normal distillation of high boiling stuff like the plague. They prefer crystallisation for purification whenever it's possible.
What are industrial methods for purifacation of high boiling oils (that cant be crystalized)?
Besides, it makes no sense to process such big amounts. A continuously running conventionally sized glass-made still can produce several liters of distilled precursor or product every day.
You are not the first bee dreaming of becoming the local Escobar of the Ecstasy trade. Everyone lives through such dreams of grandeur at the beginning of their career.
Not dreaming, just doing my part in the war.
Osmium thanks for the post. No one is trying to kid anyone here, this thread is strickly for informational purposess only.
(Stoni's sexual toy)
06-08-02 01:44
No 318683
> What would be the largest you could go for the setup
> described and still have it be pracatically fuctional?
I don't know, that can't be easily answered. Depends on many factors. Vacuum requirements, vacuum pump size, mode of stirring, if and how you introduce air through capillaries (to avoid bumping) etc.
Work your way up slowly, do not start big!
> What are industrial methods for purifacation of high
> boiling oils (that cant be crystalized)?
They do distill them, but everybody is glad when distillation can be avoided. If they have to distill high boiling stuff then they have all the necessary equipment and experience (which we do not have).
I'm not fat just horizontally disproportionate.
(Hive Bee)
06-08-02 02:15
No 318695
What application range would thoes pumps pictured above be practicall for? They are the best/biggest motorized vacuum solution i can find.
(Newbee)
06-08-02 19:14
No 318892
it really depend on what your distilling and there are load of mechanical variables too.
essential oils in my experience are a real pain with oil pumps the low BP terpenes contaminate the oil very quickly leading to a very poor vacuum, the pump has to be heavily air ballasted and the pump/oil has to run hot in order to wash the contaminants out of the oil.
I would however guess that being able to evacuate two or three time the swept volume in a minute would be ample provided the volatiles could be got rid of and the vacuum connections and lines are short. The leak through a capilliary several capilliaries is small, in fact the finer the stram of bubbles from a capillary the better. Alternatively vigerous stirring during vacuum distillation is very effective at preventing superheating and bumping
A quick looka those pumps.. they look much like backing pumps which work in conjunction with other pumps and cold traps. I've seen similar in large labs providing a ring vacuum, but theyre always used with traps.
if you look around there are surplus reciprocating vacuum pumps around these don't create a very hard vacuum but they handle volatiles well and are a lot cheaper than a vane type pump.
(Hive Bee)
06-08-02 21:39
No 318923
With regard to the coolong/heating coils, would you have two sets of coils, or one? If you only had one set, then you would probably have to have some sort of switching manifold for when you wanted to go from hot to cold. If you had to go from hot to cold quickly, it would present some serious problems. First off, you were talking about using high-pressure steam for the heating coils. The only kind of cooling agent I can think of would be fluid, so that would mean you would have to bleed the line EVERY time you changed. And if you had to go from really hot to really cold quickly, not only would you go through the bitch-ass line bleeding, switch over to what you need, then when you got ready and started up, the rapid temp change could cause some pretty bad warping. And if you had two sets of coils, it would cut out the hassle of bleeding the line every time, but it could still cause warping.
Do not go gentle into that good night. Rage, Rage, against the dying of the light. --Dylan Thomas
(Hive Bee)
06-09-02 04:58
No 319031
if you dont have a copy of Perrys Chemical Engineers' Handbook in's in youre college library (mine's next to my Merck Index).
Nothing but data regarding very big rxns/scaleups - more geard towards the continuous processes (like oil refining) vs the 'batch' processes (like drugs) - but good hard data everywhere.
"Chemists make grams, Chemical engineers take what the chemists did and use it to make tonnes - of product and money - Hence 'Engineers are the pimps of science'" -
Where the FUCK is my medication!
(Hive Bee)
06-09-02 21:05
No 319167
Obia:
it really depend on what your distilling and there are load of mechanical variables too.
essential oils in my experience are a real pain with oil pumps the low BP terpenes contaminate the oil very quickly leading to a very poor vacuum, the pump has to be heavily air ballasted and the pump/oil has to run hot in order to wash the contaminants out of the oil.
I think initial simple distillation up to reasonable temp and maintained there for some time will effectively remove water and low BP volatiles - as is basic lab process anyway to avoid undo bumping for vacuum distillations. Also in an old post of an archived thread Post 107852 (psyloxy: "Re: Info Request - Lost Archives", Methods Discourse) Eleusis gives a method for the solvent extraction of terpenes followed with subsequent vacuum distillation. Also on the topic of terpenes, Masaki Sato, Motonobu Goto and Tsutomu Hirose,"Supercritical Fluid Extraction on Semibatch Mode for the Removal of Terpene in Citrus Oil" Ind. Eng. Chem. Res., 35, 6, 1906-1911, 1996
The leak through a capillary several capillaries is small, in fact the finer the stream of bubbles from a capillary the better. Alternatively vigorous stirring during vacuum distillation is very effective at preventing superheating and bumping
Is vigorous stirring the present industrial method of choice for bumping control? Are capillaries still used on an industrial scale and if so what is the mechanism that is used for the introduction of air and how is it regulated/monitored? As Rhodium stated in Post 253541 (Rhodium: "Re: Sassy distillation problem", Newbee Forum), "the outdated practice of using a fine capillary for the introduction of air".
A quick looka those pumps.. they look much like backing pumps which work in conjunction with other pumps and cold traps. I've seen similar in large labs providing a ring vacuum, but theyre always used with traps.
Can you describe these systems in greater detail? What is a cold trap and what is a ring vacuum?
El_Zorro: Steam heating is the more effective method, but for the purpose of this discussion lets consider oil heating for now as it is more practical. Additionally it probably would not be needed to go from heat to cooling rapidly enough to make use of a second run of coiling. The oil could be evacuated and cooling fluid circulated from an alternate source probably within 15 min.
TMF: Thanks for the reference! I'll have to check that out soon. One can order it online from BN.com for 119.95 or 295.00 on cd-rom! Any other suggestions for books to read that might be helpful?
(Hive Bee)
06-10-02 00:07
No 319210
oil heating would definately cut down on the labor, just try to avoid reactions that need drastic temp changes to happen rapidly.
Do not go gentle into that good night. Rage, Rage, against the dying of the light. --Dylan Thomas
(Hive Bee)
06-10-02 08:58
No 319311
It perhaps would be nearly impossible to design and build a vessel, 50 gal in capacity that which could be vacuumated to the point where product oils could be distilled efficiently for the simple reason that the structure could not be economically built to withstand the atmospheric forces, as sighted above. With an internal pressure of 1 psi, the force on the lid would be 6,328 lbs!
Therefor what design elements would have to be present to function under these conditions?
Its desired that the body material be thin enough so that the coils supply as direct a means of heat/cooling as possible. However it is also key that vacuum distillation be applicable to the design. I came up with these general ideas on solutions, again this isn't my area, and your input would be appreciated:
* Thicker steel - would allow for more stress on the body, while it would mean less efficiency of the coils primarily in the application of heating however flame heating may counter this loss of efficiency.
* Design elements such as stiffening bars as suggested could be used. The most practical placement for these bars I think would be on the inside. Lengths of heavy steel bar could be welded to the inside of the tank at regular intervals, and would allow for more support of the lid.
* Downsizing of the vessel most obviously should be done - while holding to the optimum material thicknesses and the dimensions given, a reduction of size to 20 gallons would mean 60% less stress.