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column size and run time?

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I'm looking for run times according to column size. 100gal boiler running a 4 inch column would run x time slower than a 100 gal with an 8 inch column?

Ballpark figures works for me.

Thanks

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I'd say that your heat input is going to be the biggest factor. Your heat input is proportional to your run time, your column needs to be sized to handle the vapor produced by the given heat input.

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agree with Ursa Major: rule of thumb (ballpark figures): If your condenser has equivalent cooling capacity as your heat source, at the beginning of a run you can get about 1gph per inch of column diameter. 4" run hard can gen 4gph at start, 8" column 8gph......but no one runs their stills at the higher temps to get this kind of flow rates for 2 reasons: affects taste (mad liquor), and most condensers are too small for the columns. So realisticly most columns with their undersized condensers will produce maybe half the above. Paul-CSA

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actually double the diameter can handle 4x the throughput. there is an art in balancing boiler size and column diameter. too small a column and its the choke point, too large and the volume needed to fill the plates is a significant portion of the alcohol in your wash.

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Also the fact that the amount of cooling water will be less (like saying your heat exchanger is too small) going through the smaller column.

The relationship to the amount of plates inside the column matters as well.

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OK, looking for the ratio mentioned above: Never considered this before, what is the still size in gallons vs maximum column diameter optimal ratio? Ex. 100g/4"=25:1, 100g/6"=16.7:1 Paul-CSA

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If a typical still is sized correctly, a run time of 3-6hrs would be ideal IMHO. Too fast, and you may loose the ability to properly define cuts. Throwing more heat at a small column will make it run faster, but that's not a good thing. An undersized column will dramatically increase run time due to lower output rate.

Perhaps a better question would be "what is the typical output rate of a given sized column?" This would allow one to estimate the run time and size the boiler/column proportionate to one another.

A 4" column can do 2-3LPH+, and a 12" can do closer to 20-25LPH+. On a correctly sized boiler, both would yield a 4-5hr run (not including heatup time). There's no point putting a 4" column on a 300 gallon boiler, just as there's little point putting a 16" column on a 30 gallon boiler.

Heat up time is simply a factor of the heat exchange limits of the heating system (electric or steam) and amount of heat available (BTU/watts). More heat=faster heat up time.

Just because you have enough BTU's to bring the boiler up to temp in a short period of time does NOT mean that you can run your column at this BTU rate however, this can overpower the separation capabilities of the system resulting in a very poor product.

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We have an 8" on a 60g. We think the boiler could have been double the size, and it would have been fine. Our condenser is a 6" tube-in-shell, which we thought was overkill, but when running a strip at full, if not careful, we can still swamp it.

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actually double the diameter can handle 4x the throughput. there is an art in balancing boiler size and column diameter. too small a column and its the choke point, too large and the volume needed to fill the plates is a significant portion of the alcohol in your wash.

So what size boiler min/max would you suggest for and 8" column?

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we have a 8" on our 60 gallon system and a 12" on our 150. both are ideally sized in my opinion.

And the run times would be?

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as a straight comparison, lets say grain mash at 8% to finished spirit at 75%

60 gallon run time is about 4 1/2 hours including heat up

150 is about the same.

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What's the typical power input and gph on the 60 & 150?

Re: 75% finished spirit, going through how many plates?

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It is a lot more than just the size of the column and the heat been input into the boiler. To me the size of the condenser is a Irrelevant because that's a matter of just thermal transfer. If your condenser cannot keep up with your output increase the condenser it's just that simple. Or just add another condenser on.

1. surface area of the boiler

2. heat input

3. Diameter of the column

4. How many bubbler caps

5. How many downturns.

For example if you had a 30 gallon boiler that I had 50 ft.² a service area it would overtake a four-inch column. With that being said the same thing with a 12 inch column and one bubbler And one turn down it would overtake that also.

I know this example is a little bit off topic but think of it also like this they small 20 pound LP cylinder only produces so much flow Per minute by a giant farm cylinder weighing down inside produces far more flow per minute. The big farm cylinders are laying on the side so during the cold winter months with the massive surface area so they can still produce the required flowrate.

I hope this helps.

Joseph Dehner

515-559-4879

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Wow, my head is spinning after reading all this, there are too many variables to give a simple answer. It is my experience that your heat control is the most important element to consider. Throw too much heat on your wash thinking that will speed things up is the wrong way to look at it. If you are running a cloudy or dirty wash, and try to push your heat to increase output will scorch your wash and ruin taste.

If you are looking for 80 to 85% product you can run at a much higher output than trying to get a 95% product. We are running a neutral spirit and being careful with heat have found that we can comfortably get approxmimately:

1.15 gph from an 4" column

2.1 gph from an 6" column

3.35 gph from an 8" column

I wish it were that simple, but it depends on your wash, your heat, and what you are looking for coming out of the condenser. We have topped out with an 8" column on a 100 gallon boiler with an 80 gallon charge. We are using direct submersion electric heat, and have found that is just about all the wash our electric heat should handle. I just had to put my 2 cents in (that may be all it is worth). Good Luck!!

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We are using direct submersion electric heat, and have found that is just about all the wash our electric heat should handle.

this is why we limit our electric systems to 60 gallon charge, much larger then that and it just not economical.

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I don't agree. Electric power is in most cases cheaper. And with the element submerged in the liquid the heat transfer rate is far superior to that of steam jackets, And the cost of natural gas or LP. I would say electric is okay up to somewhere around 300 gallons. 100-150 no problem. The electric set up is quick and easy and cheap, whereas installing a steam boiler is very expensive itself just for the unit. Let alone the install.

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