General Tunnel Pasteurizer questions.....
General Tunnel Pasteurizer questions.....
Asking these question to try and get a kick in the head about trying to optimize our pasteriser. Maybe new technology or tweaking a valve or two, to get a little more out of a little less.
Tunnel pasteurizer; how are you treating pasteurizer water? (Drain and clean, chemical, combination of both, other)
If treating with chemicals, what?
Environmental or pasteurizer issues with the chemical?
What is your target Pasteurization temperature or estimated Pasteurization units?
Different bottle size or product different temperuture?
How many zones do you have? (pre-heating, pre-Pasteurization, Pasteurization, cooling)
Any estimates on water and power consumption?(actual)
Are you recovering water?
Any other comments
Pasteuriser chemicals - suggest you get a reputable chemical supplier such as Ecolab, Sopura, Diversey in to have a chat. They will be in a far better position to advise, based on water turnover, water composition, what you are pasteurising, i.e. cans, bottles, and the types of material, pasteuriser construction materials, local effluent bylaws. I'm sure there are other things to consider as well
PUs - see if you can borrow a Redpost (ideally) or an old fashioned Thermograph off someone, with decent instructions how to set up. Typically the cold spot of cans / bottles is approx midway up the main body, so the temperature probe needs to be in this region. Then get a trend of the temperature in the beer in the package. PUs start accumulating above about 55 deg C, the standard being 1 PU is given by 60 deg C for one minute. Double the time, double the PUs. For every 3 deg C (approx), the PUs double for a given time. The temperature scale / PUs is logarithmic
Typical PU spec is between 5 and 50 PUs, a norm being perhaps nearer 20, but that assumes good quality (KG) filtered beer. Aim to get the temperature up quickly by a series of increasing temperature sprays, at say 35, 45, 65, then the pasteurisation zone around 60, 61 C for 15 to 20 minutes, then rapidly cool. Recycle water from pre to post pasteuriser zones for energy efficiency. Have a look at teh websites for Krones, KHS, SIG Simonazzi, Sander Hansen (part of Krones I think) for examples from their pasteuriser systems
Bigger bottles will need longer times or higher temperatures to achieve the same PU spec
You simply MUST reuse water - it costs too much in water, chemicals, energy and effluent not to
Thanks for a reply!
As far as chemicals, we have talked to the reps and what they offer are chemicals that I donít want the MSDS sheets in the brewery, never-mind the chemicals!(will kill bacteria..... and everything else within a 10km radius!) We are trying to work with the local authorities and have discontinued use of some chemical because of there concerns. Besides the local authorities we are somewhat limited on chemical use in the Pasteuriser, although most parts are stainless steel the pumps are cast iron. As far as chemicals, I am looking at a Hydrogen peroxide based product. Other options are filtration and UV. Has any one used any of these for treating Pasteuriser water?
We are pasteurising only glass bottles at this time, but 7 different sizes from 25cl to 75cl, thus making it a little more difficult to optimise each size.(trying to do one size at a time.)
We do have a data logger and run (try to) it through each batch. It is set up for 33-50cl(probe is centered in the main part of the bottle) and trying to purchase another for the 75cl.
At this time we pasteurise at the high end (45-50 Pus) until we are more confident in the product and Pasteuriser. ( Micro checks, forcing and other QC test)
The Pasteuriser reuses water, cooling water reused for preheating and vise versa.
As far as reusing/recycling waste water I would be interested in seeing or hearing about actual set ups as far as how it is set up and runs.(tanks, piping, pump, etc)
Waste water is from cooling down the cooling water. basically the pasteuriser adds cold water until the temperature is reach, the excess goes into an overflow pipe and down the drain. (Getting more heating then cooling)
Don't forget that UV and filtration might clean up the water going in to the pasteuriser, but will not kill any bugs growing up, as tehy do, in the pasteuriser system, especially in the preheat and ppst pasteuriser sections, so you really need to use a chemical.
Strangely enough I know that hypochlorite is used in some stainless pasteurisers, which goes against everything that is ever said about chlorine & stainless. Not sure what the level is, and what other chemicals are also used.
I think you you use chlorine dioxide, possibly even ozone, but am really not sure, especially about the latter. I know many countries frown on its use where there may be contact with product, as say a plant sterilant rinse, and it decomposes very quickly at high temperatures, so may be totally ineffective.
H2O2 will also decompose very rapidly, too rapidly I suspect to be worth using. Again, I am not sure
Re the actual layout and design, I know the basics from working with them as a bottle / can line managerand from the diagrams from the various suppliers, but not as an engineer
If I get time to dig around and find anything....
There does not seem to be much online relative to the comparison of tunnel and flash pasteurization. There is a case study online at pasteurizers.info for tunnel vs. flash. Not sure how thorough it is but is one of the few "two sided analsysis" and one of the only online studies which seems to be out there. Interesting information...
Last edited by thesteig; 06-03-2009 at 09:33 PM.