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  • Neck down steam to vessels?

    About to take possession of a 20bbl brewhouse, and am curious about necking the steam supply down to 1". The vessels come with a 2" NPT fitting for steam, but have seen and been told it is common to run 1" control valves instead. We are powering with a 50 BHP Columbia boiler....

  • #2
    Just fitting a smaller valve should not restrict the flow of steam too much. It will however give you better control when trying to adjust the amount of steam applied, since you're using more range of the valve. What pressure are you running the steam at?
    Unless your boil kettle has a small surface area for the wort to contact the heating surface, or you're running on a really low pressure I think you would be fine.
    We use a valve the same size as the piping, but we never have to open it up more than maybe 1/4.
    Marius Graff,
    Head Brewer, Graff Brygghus
    Tromsø, Norway

    Comment


    • #3
      Originally posted by MariusGraff View Post
      Just fitting a smaller valve should not restrict the flow of steam too much. It will however give you better control when trying to adjust the amount of steam applied, since you're using more range of the valve. What pressure are you running the steam at?
      Unless your boil kettle has a small surface area for the wort to contact the heating surface, or you're running on a really low pressure I think you would be fine.
      We use a valve the same size as the piping, but we never have to open it up more than maybe 1/4.
      I tend to run the boiler at the full 15psi. The manufacturer of the system will only tell me that they designed it for 2 inch but also said it may work, but they couldn't tell me for sure.....

      Comment


      • #4
        With a 2 inch pipe at 15 psi you will have a lot of steam, almost regardless of the size of the valve. Our boil kettle has side jackets and a internal calandria. We only open the valve to the jacket about 1/4 and to the calandria just 1/10. With a smaller valve you will have an easier time making slight adjustments.
        Marius Graff,
        Head Brewer, Graff Brygghus
        Tromsø, Norway

        Comment


        • #5
          it might be smart to hire a boiler mechanic?
          maybe illegal to hook your boiler up without one?
          if the control valve is undersized it may not allow steam to flow fast enough to boil your wort. Here is how you calculate:

          there is a steam fittings company: spirax saarco that have a really comprehensive textbook on setting up steam systems.
          read this:

          Read about the principles of steam engineering and heat transfer and discover our guides to best practice for all aspects of steam and condensate systems.



          anyway, what you need to do is calculate the amount of steam you will need:

          heating wort: Q= Mass x Cp x delta T where Cp is the heat capacity of wort at atmospheric temp (assuming your kettle is vented to the atmosphere)

          boiling Q = Mass of water evaporated x latent heat of vaporization (amount of heat required to boil off the water)

          ie if you want to knock out 20 bbl, and evaporate 10%, you collect 22 bbl and boil off 2 bbl to wind up with 20 afterwards. you need to heat it up from your lauter temperature to boiling temp then add enough energy to evaporate 2 bbl of wort.

          you take the energy you need per hour and then using a steam table calculate how many pounds of steam you need to provide this. (at the steam pressure you operate at, every pound of steam condensed to water gives off a specific amount of heat.)

          when you know how many pounds of steam per hour you need to provide to the jackets and the diameter of the pipe, you can calculate the velocity of the steam in the pipe.


          from spirax saarco:

          As a general rule, a velocity of 25 to 40 m/s is used when saturated steam is the medium.
          40 m/s should be considered a practical limit, as above this, noise and erosion will take place particularly if the steam is wet. Some National standards quote velocities up to 76 m/s for saturated steam. This can only be feasible if; the steam is dry, the pipe is very well insulated, relatively short, straight, horizontal and can supply the required pressure at the point of use.
          Even these velocities can be high in terms of their effect on pressure drop. In longer supply lines, it is often necessary to restrict velocities to 15 m/s to avoid high pressure drops. It is recommended that pipelines over 50 m long are always checked for pressure drop, no matter what the velocity.
          By using Table 10.2.4 as a guide, it is possible to select pipe sizes from known data; steam pressure, velocity and flowrate.​

          Oversized pipework means:
          • Pipes, valves, fittings, etc. will be more expensive than necessary.
          • Higher installation costs will be incurred, including support work, insulation, etc.
          • For steam pipes a greater volume of condensate will be formed due to the greater heat loss. This, in turn, means that either:
          - More steam trapping is required, or
          - Wet steam is delivered to the point of use.


          Undersized pipework means:
          • A lower pressure might be available at the point of use, which may hinder equipment performance.
          • There is a risk of steam starvation due to an excessive pressure drop.
          • There is a greater risk of erosion, waterhammer and noise due to the inherent increase in steam velocity.

          good luck.

          and don't forget to install a vaccuum breaker/ thermal air vent on every jacket. otherwise when you shut off the steam and the tank cools it will either try to suck condensate into your jacket or just create a vaccuum in the jacket until it implodes...

          respect things that can clobber you!
          Read about the principles of steam engineering and heat transfer and discover our guides to best practice for all aspects of steam and condensate systems.
          Last edited by beerme; 11-17-2016, 06:16 PM.

          Comment


          • #6
            Originally posted by beerme View Post
            it might be smart to hire a boiler mechanic?
            maybe illegal to hook your boiler up without one?
            if the control valve is undersized it may not allow steam to flow fast enough to boil your wort. Here is how you calculate:

            there is a steam fittings company: spirax saarco that have a really comprehensive textbook on setting up steam systems.
            read this:

            Read about the principles of steam engineering and heat transfer and discover our guides to best practice for all aspects of steam and condensate systems.



            anyway, what you need to do is calculate the amount of steam you will need:

            heating wort: Q= Mass x Cp x delta T where Cp is the heat capacity of wort at atmospheric temp (assuming your kettle is vented to the atmosphere)

            boiling Q = Mass of water evaporated x latent heat of vaporization (amount of heat required to boil off the water)

            ie if you want to knock out 20 bbl, and evaporate 10%, you collect 22 bbl and boil off 2 bbl to wind up with 20 afterwards. you need to heat it up from your lauter temperature to boiling temp then add enough energy to evaporate 2 bbl of wort.

            you take the energy you need per hour and then using a steam table calculate how many pounds of steam you need to provide this. (at the steam pressure you operate at, every pound of steam condensed to water gives off a specific amount of heat.)

            when you know how many pounds of steam per hour you need to provide to the jackets and the diameter of the pipe, you can calculate the velocity of the steam in the pipe.


            from spirax saarco:

            As a general rule, a velocity of 25 to 40 m/s is used when saturated steam is the medium.
            40 m/s should be considered a practical limit, as above this, noise and erosion will take place particularly if the steam is wet. Some National standards quote velocities up to 76 m/s for saturated steam. This can only be feasible if; the steam is dry, the pipe is very well insulated, relatively short, straight, horizontal and can supply the required pressure at the point of use.
            Even these velocities can be high in terms of their effect on pressure drop. In longer supply lines, it is often necessary to restrict velocities to 15 m/s to avoid high pressure drops. It is recommended that pipelines over 50 m long are always checked for pressure drop, no matter what the velocity.
            By using Table 10.2.4 as a guide, it is possible to select pipe sizes from known data; steam pressure, velocity and flowrate.​

            Oversized pipework means:
            • Pipes, valves, fittings, etc. will be more expensive than necessary.
            • Higher installation costs will be incurred, including support work, insulation, etc.
            • For steam pipes a greater volume of condensate will be formed due to the greater heat loss. This, in turn, means that either:
            - More steam trapping is required, or
            - Wet steam is delivered to the point of use.


            Undersized pipework means:
            • A lower pressure might be available at the point of use, which may hinder equipment performance.
            • There is a risk of steam starvation due to an excessive pressure drop.
            • There is a greater risk of erosion, waterhammer and noise due to the inherent increase in steam velocity.

            good luck.

            and don't forget to install a vaccuum breaker/ thermal air vent on every jacket. otherwise when you shut off the steam and the tank cools it will either try to suck condensate into your jacket or just create a vaccuum in the jacket until it implodes...

            respect things that can clobber you!
            http://www.spiraxsarco.com/Resources...pe-sizing.aspx
            Thank you so much. Yes we are hiring a certified boiler installer, but he thinks we dont need 2". But at the same time he is not a brewer.... I have a few guys around be that are running 15 bbl systems that are necking down, but keeping the 2" seems safe. But obviously the cost goes way up vs necking it down. I am going do dig thought the calcs you gave me this evening. Again, thank you.

            Comment


            • #7
              here is part of a spirax sarco manual describing the functioning and need for an air vent.

              I have a really good steam setup manual on pdf if you want to pm me your email. it is 5mb

              s30_01.pdfs30_02.pdfs30_04.pdfs30_03.pdf

              Comment


              • #8
                Originally posted by beerme View Post
                here is part of a spirax sarco manual describing the functioning and need for an air vent.

                I have a really good steam setup manual on pdf if you want to pm me your email. it is 5mb

                [ATTACH]40534[/ATTACH][ATTACH]40535[/ATTACH][ATTACH]40536[/ATTACH][ATTACH]40537[/ATTACH]
                That would be extremely helpful. Really appreciate anything.. I will p.m. you here soon. Again, extremely appreciative!

                Comment

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