steam performance issues

[dereknobleluke]

Hello all...looking for advice here.

I have a 10 bbl crivellar system we use like a "60 bbl" system. Our "brew day" begins on tuesday morning and we mash 6 consecutive brews through wed night. That way we can filter all together, clean all together, keg all together etc. Very efficient. One thing not so efficient of late is my boiler. The quality of my boil and length of time to get the kettle to boil have changed!
1) Steam trap to kettle (top and bottom jacket) is fine. Inlet side is 230 F outlet is 168.
2) black pipe to side jacket and bottom jacket is 230 F
3) new controller switch and boiler is operating between high and low fire fine and maintaining 12-14 psi
4) installed a drain on bottom of kettle steam side...getting flow, not much "junk" and solids in kettle (if at all...)
5) no "knocking" going on
6) hot water tank has not experienced loss of performance...seems isolated to kettle
7) boil start times have gone from 3.5 hours to 5 hours plus. Boil has lost vigor and has become the dreadful homebrewing "slow rolling boil" rather than the vigorous angry boil I desire.


I have treated my boiler with chemicals religiously for 6 years. Flex tube boiler. Chlorides and alkalinity are fine.

Any suggestions?

[rudge75]

Are you getting Calcium deposits on the inside of your brewkettle?

[dereknobleluke]

brew kettle is CIP'ed after every brew....down to shiny stainless before the next week. There are some sugars that caramelize on the inside wall from the previous batch..but again this recent decrease in performance is something that I have only noticed i nthe last two months.....we have been brewing at capacity for five years...

[The Chief]

Is there any chance that your thermocouple is goofy (i.e. are you setting it to 212-214F, and the controller thinks that kettle contents are hotter than actual)? Long shot, I know, but on our 25 bbl Criveller we just use manual valves to control the amount of steam to the kettle jackets, and we basically have to go full blast right out of the gate to achieve boil simultaneously with kettle fill. Maybe you are already in the same boat, or maybe you can set the solenoid to some outrageously high temp that you'll never obtain?


For what it's worth, I've found that we get more "vigorous, angry boils" when CIP DOES NOT take the kettle quite down to "shiny stainless". The working theory is that although heat transfer may not be as direct as when shiny, there are more nucleation points for the wort to get jumping off of.

[gitchegumee]

Although it seems that this would have happened sooner, something that might be going on is air entrapment. When the jacket is cooling it will suck in air which "blinds" the jacket from seeing full steam. There is an invaluable device known as an air eliminator that may help. Good luck!

[bunnyfeet]

A couple thoughts I had based on some issues we've had on our mash:

Any significant difference in pressure between your supply (header) pressure and the pressure just upstream of each jacket? This might indicate a valve that's stuck partially shut restricting the flow. Such a pressure drop can make it hard for the trap to discharge adequately, since their sizing is partially dependent on pressures.

Do your traps have a test port, so that you can observe their discharge behavior? They should be discharging intermittently and not continuously. Could be related to the above problem, or could be an issue with the trap itself. If there is no test port you might see if there is some other way to observe the discharge.

Our issue turned out to be that some previous piping changes caused too much pressure loss between the header and the jackets, such that the pressure that was left wasn't sufficient to push all the condensate into the return header through the traps sized for a higher jacket-side pressure. In addition, the restrictions reduced the steam flow to below the actual demand of the jackets - opening up the jacket drain upstream of the trap gave no live steam, just condensate, indicating that we were using every bit of steam we were supplying. Thus we were backing up condensate into the jackets as well as starving the jackets, resulting in slow heating.

Hope this helps!
Brandon

[Larry Horwitz]

Number one problem I see here is usually that you've installed to wrong steam valve....usually with too small an orifice. Since you just replaced it, and then the problem started I go to the valve first. Remember that the pipe size of the valve is in no way related to the actual size of the hole in the middle!! We have been buying 2" steam solinoids for years and just came to find out that the hole is only 1.25"....so we've been wasting all that money on 2" steam pipe!!!

good luck

[gitchegumee]

Larry, valve orifices are sized as "reduced", "standard port", and "full port". If you use a standard port, which it sounds like you are, you are not wasting money on 2" piping. The velocity of the flow will increase nominally through the valve, but the pressure should recover nearly completely. The main drag of the system will almost certainly be the (very long) piping, and not a single valve. Just the same, it's good to be aware that valves come with different port sizes and that you can get the full port if you feel it gives you something. Good luck!