Difficult to achive boiling on a 500lt kettle

[henryg]

Hello fellows i'm testing my brewpub equipment for boiilng times and i having some issues.
This are my burners:
2 STAINLESS STEEL GAS BURNERS 26 kW (high power) diameter 560 mm
1 STAINLESS STEEL GAS BURNER 35 kW (high power) diameter 740 mm

This are my kettles:
Mash / diameter: 930 mm – height 800 mm
boil / diameter: 930 mm – height 800 mm
sparge / diameter 720mm – high 800mm

I'm using the small gas burner to achive boil, is this wrong ? should i use the big burner for boiling and small boiler for mashing? I had to tune the small boiler by replacing internal parts of the gas valve to achive more flame.
i'm using the small one since when i bought the equipment in the factory they had it mount it like that. Big burner for the mash, and small burners to sparge and boil. I emailed the factory but no response yet.

it took :

Also i took a picture from below, i had to put some woods to bring up the burner, should the flame be touching the kettle?

Waiting for you response, this is kind of urgent since i will making the first batch this weekend.
Thanks

 

[bionut]

4 hours to get to a boil seems lile a lot. With proper mashtun isolation you wouldn't need to have a burner under it, so use the bigger burner for boiling and the the little one for mashing, if necesary. Please post some pics with your kettles and brewery. 500 l is a little more than we used to see around here.
I think the burner is ok where it is, no need for the visible flame to touch the kettle. If you still have problems getting to boilling temperature after switching the burner you may try to make some kind of shield around the kettle to restrain the rezidual heat around the kettle's wall, or even use both the burners under a single kettle.
That's why bigger that homebrew level breweries use electric or steam heating afterall.

 

[day_trippr]

26kw is pathetically undergunned for the task...

 

[henryg]

4 hours to get to a boil seems lile a lot. With proper mashtun isolation you wouldn't need to have a burner under it, so use the bigger burner for boiling and the the little one for mashing, if necesary. Please post some pics with your kettles and brewery. 500 l is a little more than we used to see around here.
I think the burner is ok where it is, no need for the visible flame to touch the kettle. If you still have problems getting to boilling temperature after switching the burner you may try to make some kind of shield around the kettle to restrain the rezidual heat around the kettle's wall, or even use both the burners under a single kettle.
That's why bigger that homebrew level breweries use electric or steam heating afterall.

this is the brewhouse. Direct fire, i have connected it to the gas line.
I will post pictures of the brewery soon, i have a little mess going around the place still, finishing this finishing that.

I will try with the big burner today for the boil kettle.
What do you mean i won't need a burner under it for the mash tun? It is a direct fire system.
I tested yesterday the amount of heat that is being loss by the sides of the burner and it's huge, i definetly will make some walls as you said so i don't loose the huge amount of heat. And then ift's necessary insulate.
Thanks!

 

[henryg]

26kw is pathetically undergunned for the task...

What about the 35kw?
Do you have some recommendation pf kw for each kettle?
Thanks

 

[henryg]

quick update. It seams to retain the heat better but although with the 35kw heater it doesn't go up that fast. What do you recommend ? Mod the 35kw to don't loose heat or buy another burner?
When i mean mod the burner i mean this

Adding an inner metal wall to it.

 

[day_trippr]

35kw is ~120kbtus per hour. That's roughly my peak power level - for 10 gallon batches on a rig using 20 gallon kettles.

I'm not saying the power needs to scale linearly, but I have to believe you need a lot more power to keep the batch time reasonable...

Cheers!

 

[Lax coach]

Definitely seems way small. 26kw is about 89kbtu, or four times the output of the "big" burner on a modern stove. Those would realistically be expected to boil 4-5 gallons of water. Here you're talking about boiling 132 gallons. Some quick Googling suggests that 200+ kbtus is necessary.

Simple math says that a burner that is 100% efficient requires about 1200btu to boil one gallon of water in one hour. Therefore in a perfect world, you would need a 160kbtu (47kw) burner minimum for your pot. However, burners are typically never anywhere even remotely close to perfect efficiency--often it's closer to 50%--so that's where the 200k-320k recommendations come from.

For a real-world example, MoreBeer sells this 100kbtu burner:

https://www.morebeer.com/products/b...l?a_aid=winninghomebrew?a_aid=winninghomebrew

Which they claim can support a kettle of up to 25 gallons. Again, your pot is 5x this amount.

 

[henryg]

Finally when i was about to make a hole new propane gas installation i discovered some backstop fittings that were put in my natural gas installation, they were also reducing the gas flow.
Now gas flow 3 times power than before!
in the future i might change the burners but for now they are ok!
THank you all for the answers