SPP packing questions?

[drinkingdog]

Been reading past couple days about SPP packing and I think I want to to to make some to try in a 4 inch column. If I remember right sizing needs to be 1/10 column dia. If my math is correct that would end up 1.016 mm, or .04 inches. If I'm wrong please correct me. Then length I think the post said 15 percent column dia. Are these sizes still good for optimal performance? Most of the info I read is from older posts.

[still_stirrin]

Small packing will hold up the descending condensate longer. With a 4” column, you’re probably pushing up a lot of vapor (4.5-5.5kW, right?) so small, tight packing could create flooding conditions. The dimensions of coils you’ve outlined should work in your column as it’s “open area” will be proportional to the column dimensions, thus giving adequate retention time without plugging the upflow of rising vapors.

Personally, I use 12mm glass marbles in a 2” column. It works good in my instance, allowing me to draw azeotropic product throughout the run with as little as 1.5-1.8kW of input power. But it won’t produce near as fast as your 4”.

I don’t have the tools to make SPP, nor can I justify the cost to buy it when the cheap (somewhat disposable) hobby store glass marbles are available and function so well in my column. But YMMV.
ss

[bluefish_dist]

Volume goes up quickly in a 4". SPP is expensive in a 2", would not want to price it in a 4". Scrubbies work well in a 4". I could hit azeo at 1 gal/hr with 6' and a couple of plates, but it ran better at 1 plate and 8'.

[DAD300]

Dia approx ~1/10th the dia = 10mm]
The length should be ~150% of the dia.
100mm column = 10mm x 15mm spp

Made from .030 wire, will not crush under it's own weight.

24"s of column will take almost a gallon and weigh about 13lbs.

Sounds big compared to the tiny stuff for sale but works fantastic in 4".

[drinkingdog]

Thanks for the reply's everybody. thanks for the correct math DAD and answering one of my next questions about what size of wire would be best. Been using lava rock with good results for a good while and I know there is probably no bad effects or issues from using it. Just wanting to try something else that I know is good in efficiency and for sure without a doubt safe. Of course with a 4" column it will take a good bit of SPP to fill it. Besides not seeing the size I need forsale and the cost of even the smaller stuff I'm going to try to make it myself. Glad to hear that 0.030 size wire is what I need since it is cheaper and I'm glad I didn't already buy the smaller wire. It may be harder to make being stiffer than the smaller dia. wire though. Hopefully it will work out. I had one other question right now with more on the way (probably) once I start to try to make this stuff, but my question for now is what seems to be the most efficient shape. I have read BigSwede's thread on his SPP machine he made and he showed a few different shapes that he made. That thread being over 4 years ago and the fact that I'm filling a 4 inch column I thought it would be nice for the ones that have made, bought, and used SPP to chime in on what would be the correct or best shape. Thanks again.

[seamusm53]

After reading about it here - as an experiment I bought some SPP - the shipping surprisingly was pretty fast. This stuff is teeny tiny wire loops. How do people keep it in the column? and how do you clean it after a run? Sorry to steal your thread, drinking dog.

[Manc]

After reading about it here - as an experiment I bought some SPP - the shipping surprisingly was pretty fast. This stuff is teeny tiny wire loops. How do people keep it in the column? and how do you clean it after a run? Sorry to steal your thread, drinking dog.

Hi seamusm

I've found the best way is to roll up copper mesh to make a tight fit in your tube and use that as a stopper it also puts copper in your vapour path.

Lee

[seamusm53]

After reading about it here - as an experiment I bought some SPP - the shipping surprisingly was pretty fast. This stuff is teeny tiny wire loops. How do people keep it in the column? and how do you clean it after a run? Sorry to steal your thread, drinking dog.

Hi seamusm

I've found the best way is to roll up copper mesh to make a tight fit in your tube and use that as a stopper it also puts copper in your vapour path.

Lee

gratias

[drinkingdog]

You haven't stollen anything. This is a good post to have any question about SPP answered. Ask away.

[DAD300]

Don't get too hung up on the shape. A simple tube is 400% better than scrubbies (mesh). But here's a graph/text on the subject.

Keeping the shape on the mandrel is hard, but once you get that down, cutting it is the drudge work.

Shapes.jpg

SPP geo.jpg

New SPP.jpg

The efficiency between more or less open is tiny but the through put is better with more open.

Most of the changes in shape are just a matter of more or less tension and length of mandrel.

[drinkingdog]

With reference to the graph there are the 2 other graphs beside the HETP graph. Are they the same as the HETP graph meaning the lower the number the better?

[DAD300]

No, the lower the number on each graph is not better, but a rating of a dif quality.

You have to chose a design the achieves your goal.

wirechart.jpg

Or as I did...design #2 is the middle of the road on all three rating, liquid hold up, HETP, through put of vapor.

[drinkingdog]

I could have sworn that one of the posts I read in regards HETP said the lower number was better which kind of didn't sound right but then again I'm not the sharpest tool in the shed. So the higher the numbers on all 3 graphs are better then just to confirm? Thanks again for your help

[drinkingdog]

So by looking at that graph the round helix has the highest HETP efficiency. Which I would think to be the easiest to make? Hope I'm right. I hate to ask so many stupid questions to some people but when I read conflicting comments on a given subject I just want to make sure that my money and time are well spent as well as help others by clarifying info regarding SPP packing

[DAD300]

The design with the lowest HETP (Triangles)has a slow rate of Throughput (output).

#2 is what I believe to be the best compromise and the easiest to make.

If you want Helix tubes, buy some 3/8" stainless tube and cut it into pieces. That's much easier!

[Yummyrum]

I could have sworn that one of the posts I read in regards HETP said the lower number was better which kind of didn't sound right but then again I'm not the sharpest tool in the shed. So the higher the numbers on all 3 graphs are better then just to confirm? Thanks again for your help

drinkingdog . You are correct in your undestanding of HEPT . A lower number is a more efficient packing than a higher one .

I believe Dad is saying that there are trade offs , and that having the most efficient doesn’t mean the best outcome as regards to through put in this case .

[richard1]

So if we are saying that a helical coil is optimum, then the next question to ask is

....... between each coil, say 10mm OD x 10mm long x 0.9mm thick, what is the optimum gap.

The comment here is so that you have good drainage.

[The Baker]

DAD300 said, .... 'If you want Helix tubes, buy some 3/8" stainless tube and cut it into pieces. That's much easier!' ....

Thanks, DAD.

Are you just actually making circles? That would be too small to twist into figure eights? Or do you cut the tube into a spring shape?
Continuous diagonal cut, not all the way through? If you see what I mean? And stretch and cut into sections later?

Geoff

[drinkingdog]

I'm not looking for the easiest. I'm looking for the best in regards to efficiency and productivity. I want the most bang for my buck. Even though I may fall short in making it

[Manc]

Hi Drinking dog

If you are looking at best effiency and output dad3000 has already given you the answer in option 2.

I am also new at this but until you run the spp it can be hard to envisage as I found out. Can I try and explain how I see it.
The most efficient hetp will allow you a smaller coloum height but as you push for more product output it will flood and no longer be viable if that makes sense. (Hope I've got that right)

I've found this out by experience but want to thank you for bringing to my attention the 10% diameter rule although I try and read as much as possible I did not see that and this post has taught me a lot thanks



Lee

[drinkingdog]

Thanks Manc that explanation helps me to understand how SPP works in regards to productivity and quality. Most posts I read a BBC out SPP were older posts and even though somethings don't change over time they can be tweaked. Since SS wire is expensive just trying to cover everything before I spend a lot of time and money trying to make SPP.

[Manc]

Hi Drinkingdog

Would it be ok to ask to keep us informed on how you get on with your spp. I'm currently running 3.5mm (triangle shape) in a 3 inch coloum and although I'm happy with the output at the moment I'm always looking to improve and there doesn't seem to be any suppliers for larger spp the largest I've found is 5mm. I wondered why people were looking for larger spp now I know why.

And I apologize for ASSuming you was a newbie like me.

Regards
Lee

[drinkingdog]

I will keep you informed. It may be a little while though. Working a lot of hours. Just because I have been around for a little while doesn't mean I'm still not a noob. A lot of this stuff goes way over my head. I'm not to bad with my hands. Brain is a lot slower now a days since I became an old man.

[Cu29er]

Been reading past couple days about SPP packing and I think I want to to to make some to try in a 4 inch column. If I remember right sizing needs to be 1/10 column dia. If my math is correct that would end up 1.016 mm, or .04 inches. If I'm wrong please correct me. Then length I think the post said 15 percent column dia. Are these sizes still good for optimal performance? Most of the info I read is from older posts.

Have you tried a column of scrubbies/copper mesh yet? I'd start there. A thread on here did a fairly good job comparing performance of scrubbies, glass marbles, SPP, and straight pipe -- showing that scrubbies were close to the same performance as SPP but wildly cheaper.

One caution... make sure you use a pot still for the first distillation and this system as the second -- if you run this one first you risk plugging the column with fermentation debris and making an uncontrolled pressure cooker out of the device. Then you're in Emergency explaining to both the spouse and the medical people how you got so badly scalded.

.

[drinkingdog]

Is there any difference in SS wire to use in making SPP. Like 304,308, or 316 wire. Also what about the letters behide the numbers on some of the wire. I know you don't want flex coated wire but that is as far as my knowledge goes in regards to SS mig wire.

[zed255]

For stainless the number indicates the composition of the material.

The first digit tells you the 'series' the material belongs to and the rest are just a designation used to distinguish one from another. SS in 304 or 316 are most common for our applications. The 316 has more alloying than 304 and tends to be more expensive and harder to work with but also more resistant to difficult environments. The letter(s) indicate special characteristics, like L means a low carbon content.

Types like 308, 309, 347 and such are rarely seen as base material but are often seen as filler materials used by welders. They often use a different alloy because the welding process alters the material properties and using a different composition for filler can mitigate some of the undesirable effects of welding.

[drinkingdog]

With that info in mind. Would 316LSi wire be ok to use for SPP

[zed255]

Yes. Don't get too hung up on the exact material. The base is 316 and the rest just says it is a low carbon with added trace silicon (not silicone) variant.

If you are using MIG wire it will be very springy and already work hardened, so be aware that it won't want to 'bend' to your will readily. You can also look for stainless 'safety' or 'aviation' wire that will be in an annealed state and very pliant.

[drinkingdog]

Sounds good thanks

[DAD300]

DAD300 said, .... 'If you want Helix tubes, buy some 3/8" stainless tube and cut it into pieces. That's much easier!' ....


Are you just actually making circles? That would be too small to twist into figure eights? Or do you cut the tube into a spring shape?

Geoff

Not making circles, making tubes. I would cut 3/8" dia tube into approx 5/8" length.

I actually did this recently because I got tired of dealing/cleaning copper mesh packing.

So, I made a quart of 3/8" x 5/8" tubes for the bottom of a 4" column. They work fine as packing and are far easier to clean. 5 feet of 3/8" tube was $5usd. For you guys looking for more copper, this might be a lot better than mesh!

Then I bought two quarts of 1/2" dia copper pipe connectors for a larger column. In bulk, they are about $12usd a quart.

I have about two inches in the bottom, just for copper content. They are behind a sight glass and they act as packing, bubbling away. They seem just as efficient as the bubble caps on the plate above them.

copper con.jpg

I have a bunch of beer keg spears. I'm going to cut them into short tubes and twist them to make a packing. It will be more like a Pall Rings or saddles, but the material is free!