Announcement

Collapse
No announcement yet.

Burner and combustion woes...

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Burner and combustion woes...

    Howdy. I have a 10hl HLT with an Economite EC300 and a 10hl kettle with an Economite RE4400DS, both burning propane. We've completed installation and fired both burners up last week. Since then, we've been troubleshooting. Argh. For starters, both tanks were seeing super high flue temps and very high CO levels. Both burners were set to full on nuke power so we switched out orifices and adjusted air intake. We were able to reduce flue temps on the HLT to safe levels but in order to do that we had to back the EC300 from it's max 300k btu's down to a dismal 100K. The kettle is still giving us grief too. We've back it down from 400k btu's to barely over 100k and are still getting super high flue temps and CO levels that are off the charts. We've adjusted everything we can think of and are totally stumped. At the EC300's current setting, I'll have to start heating the strike water on Monday for a Wednesday brew session. So, all that to say...is there anybody out there that could possibly give us some advice? Please?
    Marc Bru
    Square Timber Brewing Company
    Pembroke, Ontario, Canada

  • #2
    Burner Setup

    When you say high Stack Temperature do you mean over 500F?
    The Burner MFG. in all cases is supposed to give you Technical instructions on how to set up their unit. It should be clear and stepwise.
    If you are having problems out of the gate, you need someone who works on combustion systems all the time, like an Industrial Boiler Tech.
    Changing orifices raises red flags. That should not be necessary if the burner was specified for the fuel being used and the altitude you are at.
    The Flue has to be sized correctly, the available combustion air has to be correct and you cannot have anything inducing negative pressure into the burner room.
    Something in the design or install is off.
    Warren Turner
    Industrial Engineering Technician
    HVACR-Electrical Systems Specialist
    Moab Brewery
    The Thought Police are Attempting to Suppress Free Speech and Sugar coat everything. This is both Cowardice and Treason given to their own kind.

    Comment


    • #3
      Originally posted by Starcat View Post
      When you say high Stack Temperature do you mean over 500F?
      The Burner MFG. in all cases is supposed to give you Technical instructions on how to set up their unit. It should be clear and stepwise.
      If you are having problems out of the gate, you need someone who works on combustion systems all the time, like an Industrial Boiler Tech.
      Changing orifices raises red flags. That should not be necessary if the burner was specified for the fuel being used and the altitude you are at.
      The Flue has to be sized correctly, the available combustion air has to be correct and you cannot have anything inducing negative pressure into the burner room.
      Something in the design or install is off.
      Yes, the stack temps go past 500F about 15 seconds after start-up so we have to shut it down. We've spoken with burner mfg a few times (they guided us on the changing of orifices) and they basically said as long as the burner is firing they're not responsible for any further support. The flue is 6" single wall SS for the first 6 feet and then goes to 8" double wall. I'm sure you're right in that something in the design or install is off but the key is which one, or both, and how to fix it.
      Marc Bru
      Square Timber Brewing Company
      Pembroke, Ontario, Canada

      Comment


      • #4
        500F does not seem that high to me.

        Is your flue a natural draft type? In that it sucks room air into the flue along with combustion gases to generate flue draft?
        Perhaps you're starving the flue, or the flue is undersized.

        If your equipment supplier (the brewhouse manufacturer, that is) says it should work at 400k btu then THEY should be the ones supporting you.

        Comment


        • #5
          The vent is only rated to 475F. There is a barometric vent damper about 3/4 of the way up the stack. The ceilings are 13 feet so it would be about 10 feet off the floor. Unfortunately, the brewhouse manufacturer designed the tanks for mid-range burner settings. They have suggested some options but partially blocking the flue at the exit of the tank doesn't seem to be the safest way to go :-/
          Marc Bru
          Square Timber Brewing Company
          Pembroke, Ontario, Canada

          Comment


          • #6
            High CO levels should be a red flag. You are starving the burners for air. Have you opened your air mixture vents all the way?

            You should get a qualified combustion tech in there.

            Comment


            • #7
              Originally posted by Baldrick View Post
              High CO levels should be a red flag. You are starving the burners for air. Have you opened your air mixture vents all the way?

              You should get a qualified combustion tech in there.

              We had to restrict the air mixture vents on the burner in order to lower the stack temps and I'm pretty sure you're right and that's what's causing the elevated CO readings. Changing one things certainly adversely affects the other :-/
              Marc Bru
              Square Timber Brewing Company
              Pembroke, Ontario, Canada

              Comment


              • #8
                Originally posted by cleave View Post
                We had to restrict the air mixture vents on the burner in order to lower the stack temps and I'm pretty sure you're right and that's what's causing the elevated CO readings. Changing one things certainly adversely affects the other :-/
                Perhaps you might have an undersized barometric damper. Is it opening fully during combustion?

                Also, have you checked if you are feeding excess air to the burner?
                You may be operating at 0% excess air to have such high flue temps. Can you increase the excess air to 20% and see how that lowers the flue temperature?

                Comment


                • #9
                  Originally posted by Baldrick View Post
                  Perhaps you might have an undersized barometric damper. Is it opening fully during combustion?

                  Also, have you checked if you are feeding excess air to the burner?
                  You may be operating at 0% excess air to have such high flue temps. Can you increase the excess air to 20% and see how that lowers the flue temperature?
                  First, thanks for the replies. Any help we can get is greatly appreciated.

                  The barometric damper is in the 8" section of the flue and is fully open during combustion. As soon as we increase excess air the temps go even higher. There are no baffles in the combustion chamber and I'm wondering if it would help in any way...
                  Marc Bru
                  Square Timber Brewing Company
                  Pembroke, Ontario, Canada

                  Comment


                  • #10
                    So theoretically you are increasing the combustion efficiency with increases in combustion air.
                    I'm guessing that you might be spooking yourself hitting the high combustion efficiency mark and overheating the flue. But that's still zero percent excess air.
                    Once you start to dilute the flame a little with excess air you will probably see a lowering of the flue temperatures. You might lose some burner efficiency, yes, but you need to put more air into the flue to get the temperatures down.

                    You should do some controlled tests with this.

                    Comment


                    • #11
                      Originally posted by Baldrick View Post
                      So theoretically you are increasing the combustion efficiency with increases in combustion air.
                      I'm guessing that you might be spooking yourself hitting the high combustion efficiency mark and overheating the flue. But that's still zero percent excess air.
                      Once you start to dilute the flame a little with excess air you will probably see a lowering of the flue temperatures. You might lose some burner efficiency, yes, but you need to put more air into the flue to get the temperatures down.

                      You should do some controlled tests with this.
                      We're going to try firing up again tomorrow. I spoke with an engineer today and he didn't seem to be able to put his finger on the main problem. Thanks again for you advice.
                      Marc Bru
                      Square Timber Brewing Company
                      Pembroke, Ontario, Canada

                      Comment


                      • #12
                        Originally posted by cleave View Post
                        We're going to try firing up again tomorrow. I spoke with an engineer today and he didn't seem to be able to put his finger on the main problem. Thanks again for you advice.
                        Presumably there's a shutoff valve on the propane line near the unit right? Try cracking it halfway. We run ours full blast while filling the kettle, then choke it off during the boil.
                        Russell Everett
                        Co-Founder / Head Brewer
                        Bainbridge Island Brewing
                        Bainbridge Island, WA

                        Comment


                        • #13
                          Originally posted by Bainbridge View Post
                          Presumably there's a shutoff valve on the propane line near the unit right? Try cracking it halfway. We run ours full blast while filling the kettle, then choke it off during the boil.
                          yes, hard piped on the wall behind tanks. We're going to fire up again tomorrow and we'll add that to our list of variables to play around with. I mean...adjust.
                          Marc Bru
                          Square Timber Brewing Company
                          Pembroke, Ontario, Canada

                          Comment


                          • #14
                            Did you resolve the issue?

                            We are in the process of having our kettles welded with skirts and we will be putting 300K to 400K burners under the kettle and 300K under the HLT. We are working on vent sizing now.
                            Bill Walden
                            Oddball Brewing Co.
                            Suncook, NH

                            Comment


                            • #15
                              High flue temps=Lean mixture or too high of firing rate for the kettle

                              If you want to lower the temps, fatten up the mix, or reduce the BTU's until the kettle is absorbing more heat.

                              Comment

                              Working...
                              X