Feedback on fermenter design for our upgrades

[grnis]

I have not liked the standard specs from our suppliers, so this is what I have specified. I would like some feedback, and perhaps there is something I have missed


Volume total: 185 hl for one, two or three brews of 50 hl

Height: 6 meters. Plus 1,2 meters extra length of the legs to ease pipe installation and working with the tanks.

Cone Angle: 70 degrees

Yeast outlet: 3 inch

Filtration outlet: 1,5 inch

Cooling jackets: four: one for cone and one for 50, 100 and 150 hl

Supply pipes: Two, one for CIP and one for gas

Level meassurement: Differential pressure. One in bottom. One in gas supply pipe. Both connected via variline fittings Can't stand level pipes. They tend to clog and sooner or later they will break.

CIP inside tank: 1 inch, rotary jet heat

Glycol supply for each jacket: 1,5 inch.

Manway: In the top. Too much hassle removing the cylinder manway to clean the gasket. Also, we have had incidents where they have leaked.
Vaccum breaker: 4 inch on the top. Better safe than sorry.


Same thing with the BBT, except 165 hl, dished bottom and only one cooling jacket in the bottom.

[dick murton]

You don't give vessel ID or cone height, to be able to work out wettage volume etc. but I reckon you need 40 to 50 mm ID sprayball supply pipe to cope with the wettage requirement - I guesstimate 65 hl / hr - too much for 25 mm, but OK for 40 mm (but that is for a sprayball, not a high pressure rotary jet). Best checking with Alfa Laval or GEA specs - they are available on the web, but you also need to take into account the height, so I would go to a reputable supplier for confirmation. And why two separate pipes for CO2 and CIP - one works perfectly well providing there is a switchable valve for CIP - and you will need that for this size tank whether manual or auto, though auto will be far more reliable.

1.5 inch outlet seems small - particularly if you have to upgrade the sprayball. How fast do you want to transfer?

Better off with top pressure sensor in top dish as not prone to changes due to venture effect when venting / pressurising.

Vacuum - check with suppliers - what is the tank material rated at in terms of negative pressure (water gauge commonly quoted) and what flow rate are you running out at.

Location of temperature probes - you may want more than one depending on temperatures and volumes. Don't forget the temperature inversion at about 4 C.

Glycol - depends on glycol flow rate, glycol pressure, glycol in and out temperature and any special cooling requirements

This is specialist stuff - you need to talk to specialists

[grnis]

You don't give vessel ID or cone height, to be able to work out wettage volume etc. but I reckon you need 40 to 50 mm ID sprayball supply pipe to cope with the wettage requirement - I guesstimate 65 hl / hr - too much for 25 mm, but OK for 40 mm (but that is for a sprayball, not a high pressure rotary jet). Best checking with Alfa Laval or GEA specs - they are available on the web, but you also need to take into account the height, so I would go to a reputable supplier for confirmation. And why two separate pipes for CO2 and CIP - one works perfectly well providing there is a switchable valve for CIP - and you will need that for this size tank whether manual or auto, though auto will be far more reliable.

1.5 inch outlet seems small - particularly if you have to upgrade the sprayball. How fast do you want to transfer?

Better off with top pressure sensor in top dish as not prone to changes due to venture effect when venting / pressurising.

Vacuum - check with suppliers - what is the tank material rated at in terms of negative pressure (water gauge commonly quoted) and what flow rate are you running out at.

Location of temperature probes - you may want more than one depending on temperatures and volumes. Don't forget the temperature inversion at about 4 C.

Glycol - depends on glycol flow rate, glycol pressure, glycol in and out temperature and any special cooling requirements

This is specialist stuff - you need to talk to specialists

1,5 inch outlet seems fine. We will filter with a flow rate of 50 hl/h, so it's fine.
The rotary jet head can handle much larger tanks and one of the advantages is that you only need a one inch CIP supply pipe. But you are correct that there is no need for one gas and one CIP pipe.

One inch for glycol seems better to me.

And pressure sensor on top of the tank, you are correct. Thank you!

[dick murton]

1.5 inch outlet is fine for these filter flow rates

my cooling capacity calculators give the following values for 150 hl beer cooling by 1 deg C/ hr - 17.25, 17.68 and 18.87 kw and for 50 hl - 5.9. 5.75 and 6.3 kw. I picked these up from reputable consultancy firms, so the results should be there, or thereabouts.

Re glycol, one of these has a glycol flow calculator, and according to that, if your glycol inlet temperature is -3, the outlet temperature zero, then you need a flow rate of about 1.5 metres / sec through 25 mm ID pipe to meet the demand for 50 hl, but 5 metres / sec through a single supply pipe of this diameter to cool the 150 hl brews - which is not realistic.

So I think you should all the date etc. check with your fridge / glycol system installer

[grnis]

Our glycol temperature is -7.5. And there will be four glycol jackets each with it's own inlet and outlet.

[dick murton]

Minus 7.5 is way too cold to circulate through the cooling jackets. It will over-cool fermenting wort, and will cause layers of ice to build up on the cooling jackets, which will then cause poor cooling, and concentrate the wort, and if ice forms before completion of fermentation, you will then have unfermented wort. Even at minus 4 you are highly likely to get those problems. I know they were bigger vessels, but we have had lollipops fall down as the vessels were emptied and strip off the temperature probes - not good news.

Minus 4, or better, minus three or even minus 2. Keep it as warm as you can, with the outlet temperature as high as you can (as long as it is a couple of degrees below the actual wort temperature, it is doing its job) and still keep the fermentations under control and the desired rate of cooling. You will also save energy as the compressors will not have to work so hard.