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Boiler Questions


JohninWV

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So I'm trying to figure out some boiler "stuff".

To compare electric versus gas costs, I do this?

Gas Boiler: 700,000 BTU/h or 205 KW (3412 BTU/KW)

Gas is $14.25/MCF here in WV (1 MCF=1.027 Million BTU)

So, theroretically, I'll use .682 MCF/hr or $9.72/hr

Electric is .0578/per kw, so 205 KW equals $11.85/hr

Does that math sound right?

How much do I lose with a gas boiler in efficency?

I will be buying a Christian Carl still and will be using live steam injection on the mash and hot water tank. Who's doing this and how are you keeping the steam clean so you can do this?

I think I have it figured out with an electric boiler by dumping the condensate, but I'm looking for other experiences. I'd like to move the boiler further away, but the electric folks tell me it needs to be within 10 feet.

Thanks,

John

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Why do you want to use direct injection for mash and your hot liquor tank?

And...by mash, do you mean on the wash that's in the CC still? Or do you mean heating grains to break down starch in a mash tun?

Heating the grains in a mash tank and prepping in the hot water tank. My reasons: that's the way Carl designed it and when I used it at Dry Fly Distilling School, it seemed to work fine and work quickly. My guess is that's its more effifcient than a jacketed vessel.

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Heating the grains in a mash tank and prepping in the hot water tank. My reasons: that's the way Carl designed it and when I used it at Dry Fly Distilling School, it seemed to work fine and work quickly. My guess is that's its more effifcient than a jacketed vessel.

Wait, so Carl designed your mash tun? Or just your still?

If Dry Fly used direct steam, then I'd ask them. Personally, I wouldn't recommend direct steam for mash or a HLT. But that's just my opinion.

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John, your math looks about right (without digging into my references). Gas boiler efficiency is 80-85%. Also consider the installation costs between the two boilers.... they could vary greatly depending on manufacturer and type.

Direct steam injection is a far more efficient medium for heating as opposed to jackets. You look like you're on the right path.....

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Direct steam injection is a far more efficient medium for heating as opposed to jackets. You look like you're on the right path.....

If we're talking about sending direct steam into a simple open mash tun, I respectfully disagree.

Are you getting your water from a muni. source, John?

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If we're talking about sending direct steam into a simple open mash tun, I respectfully disagree.

it's as easy as the difference in specific heat of stainless (or copper, or any metal) versus water (and it takes 1/2 to 1/3 of the time for heating depending on jacket design and steam injection technique). I have both and there is a measurable difference.

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Heh. Well, that explains it. You're talking about the efficiency of heat transfer, and I'm talking about energy efficiency.

You are obviously absolutely correct about the speed.

But what I'm talking about is boiler, and therefore energy, efficiency.

There's some problems with direct steam injection; namely:

1. Your make up water is always cold. John is using Muni. water, which means that this is an even bigger problem in the winter. This will drop the amount of steam per hour that his boiler can manufacture.

2. It will also consume much, much more energy than a jacket and condensate return system. In a jacket and condensate return set up, once your return pipe and condensate return tank is filled with hot condensate, Bob's yer uncle. It requires very little gas/electricity to get that very hot water to boil. Taking winter water and bringing it to a boil requires much more BTU's, obviously.

3. You will lose a ton of DP from direct injection. You will denature a bunch of your enzymes. This will affect your yield....unless you use enzymes from a pail, which costs $$.

4. You can also lose yield because of Maillard reactions that will take away available sugars and turn them into unfermentable byproducts.

5. Your salt concentrations (Mg, Ca, etc.) can get out of whack in your mash pretty quick. This can affect your yeast performance.

6. The difference between the temp in your boiler and the temp of your make up water can contribute to metal fatigue, and actually create cracks in your boiler. A condensate return system is a safer method. In fact, many municipalities and States actually require condensate return. I know Colorado does. Check with your steam fitter before proceeding.

All just my opinion, obviously. There are many ways to skin a cat, and direct injection will get yer mash hotter, that's for sure.

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Heh. Well, that explains it. You're talking about the efficiency of heat transfer, and I'm talking about energy efficiency.

http://adiforums.com/style_images/ip.board...es/rte-list.gif

You are obviously absolutely correct about the speed.

But what I'm talking about is boiler, and therefore energy, efficiency.

There's some problems with direct steam injection; namely:

1. Your make up water is always cold. John is using Muni. water, which means that this is an even bigger problem in the winter. This will drop the amount of steam per hour that his boiler can manufacture.

2. It will also consume much, much more energy than a jacket and condensate return system. In a jacket and condensate return set up, once your return pipe and condensate return tank is filled with hot condensate, Bob's yer uncle. It requires very little gas/electricity to get that very hot water to boil. Taking winter water and bringing it to a boil requires much more BTU's, obviously.

3. You will lose a ton of DP from direct injection. You will denature a bunch of your enzymes. This will affect your yield....unless you use enzymes from a pail, which costs $$.

4. You can also lose yield because of Maillard reactions that will take away available sugars and turn them into unfermentable byproducts.

5. Your salt concentrations (Mg, Ca, etc.) can get out of whack in your mash pretty quick. This can affect your yeast performance.

6. The difference between the temp in your boiler and the temp of your make up water can contribute to metal fatigue, and actually create cracks in your boiler. A condensate return system is a safer method. In fact, many municipalities and States actually require condensate return. I know Colorado does. Check with your steam fitter before proceeding.

All just my opinion, obviously. There are many ways to skin a cat, and direct injection will get yer mash hotter, that's for sure.

1. Use tank-less hot water heater(s). It alleviates the cold shock to the boiler.

2. See #1

3. Inject steam before mashing in grains (strike temp) to alleviate DP loss. It takes some experimentation (and math) to get it spot on, but it's achievable, reliable, and repeatable. I get awesome, fast conversions.

4. See #3

5. Treat water pre-boiler.

6. See #1.

I looked at both methods prior to fitting the DI system. Both work wonderfully well when installed in the correct system. But steam injection is easy, fast, and a more efficient means of heat/energy transfer (for my system, anyway). A good boiler guy will get you cookin' in no time.... but most are used to close-loop (condensate return) systems. State/local regs also play a role in this.

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One of things I like about distilling (and brewing) is seeing all the different ways we come up with to get to the same goal.

I use a mash cooler, which is essentially an open tank with an 220v immersion heater that will bump up the warm mash water that comes off the heat exchanger of the previous mash. The tank also has an immersed 1" pipe coil which crash cools the mash from starch conversion temp to pitching temp. So I don't use steam for hot water production, just still operation.

I also just use one temp for mash in, with no other temp. increases. John in WV was talking about injection for his mash tun, so I thought I'd give him the heads up as to why that may be a bad idea. I will say that I like a condensate return set up better. You don't need the hot water set up that you use for your system (which costs money to buy, and you're still spending energy to heat up that make up water), and you don't need to constantly treat your water if the system is balanced correctly.

Good stuff, absaroka. I really need to visit your distillery.

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Same to you, Denver Distiller. I enjoy these technical question/answer/opinion posts.... I think it really adds to this boards' content. Like you said, there are many methods to get the same outcome.... too many variables are at play to pinpoint a be-all end-all solution.

FWIW, I don't use the tank-less h20 heaters for the boiler... they are reserved for heating CIP water etc. I have the cold water input on the drip leg section (custom built by my boiler installer) of the wet steam return. It works very well and, although there IS loss in the system, this setup keeps it minimal for what I'm doing.

John, hopefully this little discussion has helped you out!

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.... too many variables are at play to pinpoint a be-all end-all solution.

Totally agree. It's also why I love hearing about custom fabrication. Anything that makes your methods and spirits different is a great, great thing.

Plus, it's so fun fiddling with your equipment. Cookie cutter approaches suck, IMHO.

Looks like Denver is 9 1/2 hours from Bozeman. Maybe this summer our crew can head up your way?

Cheers.

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Looks like Denver is 9 1/2 hours from Bozeman. Maybe this summer our crew can head up your way?

Cheers.

8 hours if you can dodge the WY highway patrol and deer/jackrabbits/cattle on the road. I recommend coming up through West Yellowstone as the scenery is much better. I'll buy the first round of libations!

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8 hours if you can dodge the WY highway patrol and deer/jackrabbits/cattle on the road. I recommend coming up through West Yellowstone as the scenery is much better. I'll buy the first round of libations!
What if john is making bourbon and is boiling corn meal with steam injection. How would this denature enymes?
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Heh. Well, that explains it. You're talking about the efficiency of heat transfer, and I'm talking about energy efficiency.

You are obviously absolutely correct about the speed.

But what I'm talking about is boiler, and therefore energy, efficiency.

There's some problems with direct steam injection; namely:

1. Your make up water is always cold. John is using Muni. water, which means that this is an even bigger problem in the winter. This will drop the amount of steam per hour that his boiler can manufacture.

2. It will also consume much, much more energy than a jacket and condensate return system. In a jacket and condensate return set up, once your return pipe and condensate return tank is filled with hot condensate, Bob's yer uncle. It requires very little gas/electricity to get that very hot water to boil. Taking winter water and bringing it to a boil requires much more BTU's, obviously.

3. You will lose a ton of DP from direct injection. You will denature a bunch of your enzymes. This will affect your yield....unless you use enzymes from a pail, which costs $$.

4. You can also lose yield because of Maillard reactions that will take away available sugars and turn them into unfermentable byproducts.

5. Your salt concentrations (Mg, Ca, etc.) can get out of whack in your mash pretty quick. This can affect your yeast performance.

6. The difference between the temp in your boiler and the temp of your make up water can contribute to metal fatigue, and actually create cracks in your boiler. A condensate return system is a safer method. In fact, many municipalities and States actually require condensate return. I know Colorado does. Check with your steam fitter before proceeding.

All just my opinion, obviously. There are many ways to skin a cat, and direct injection will get yer mash hotter, that's for sure.

I would like to add a few things that I have done. We are also a Colorado Distillery, west slope while Denver D is on the east slope.

I designed and built my own mash kettle. It is a dual and direct injection by steam. Our water is just about the same temp as Denver. All water lines are in the ground and piped to someplace inside the building. The ground its self will hold a pretty constant temp as water lines are deep enough so as to keep them from freezing. The kettle holds 220 gallons of water with room for all the added grains. During the cooking process which takes only about 1 1\2 hours 30 gallons of water is added to the mash from the steam. That comes to about .33 gallons per min which flows very slowly into the boiler. The feeder line to the boiler is about 10' long and runs just above and across the top of the boiler. The water is plenty warm enough so as not to hurt the cast iron exchanger within the boiler. My mash run times are within minutes of each other, winter summer spring or fall. Our boiler is subject to a yearly inspection by the State of Colorado and they do not care weather you us a condensate return system or not. However some local towns and cities like Denver may have their own requirements.

Now this is in the form of a question. Enzymes, if you cook your mash to a temperature that will cook the starches out of the grain, then would this not kill any active enzymes that may be present?? After we cook and hold temperature long enough to get the starch out we then add water to cool down the mash to a temperature that will support the enzymes with out killing them. We then add fresh malted barley to convert starch to sugar and wa la. At this point we cool down further to transfer and add yeast. This is done through a 1" jacket around the kettle and by using a tank of water which is recycled over and over and over. The 450 gallon tank has had the same water in it for about 9 months. No wasted water and no further expense for cooling the mash.

You said "you will loose a ton of DP from direct injection". What is DP?

Just wondering, Coop, 5.5 hours west of Denver.

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Our boiler is subject to a yearly inspection by the State of Colorado and they do not care weather you us a condensate return system or not.

Heh. Aren't regulators great? Our State inspector wouldn't approve our system without a functioning condensate return system. Nothing like getting two different regulations.

Now this is in the form of a question. Enzymes, if you cook your mash to a temperature that will cook the starches out of the grain, then would this not kill any active enzymes that may be present??

Absolutely. If you have enzymes present in the mash, and you're north of around 170F, you're going to deactivate enzymes. That's why mashing with direct steam is a bad idea if enzymes are present. The steam moves into the mash tun at well over 212, obviously. You will lose DP. Yield can go down as a result.

If they aren't present, like Tom is asking about in the case of mashing corn and rye without distiller's malt present, and you then add your distiller's malt or pail of enzymes when the mash is at saccharification temp, no problemo.

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To all of you that have commented on this...thanks a bunch. It's great to hear all of the different opinions, options, comments, etc.

May just be that for the last 35 years. I have lived here in Cedaredge worked as a General Contractor my wife took her first teaching job here and retired here after 30 years. Small town with a voting population on about 1200. We used all local help to remodel for the distillery and had a local boy who was a student of my wife as was his wife build all our tanks and mash kettle. Nothing beats using locals for everything possible. The town gave us just about whatever we needed. Think local and the rest will come. I feel for all the ones trying to do things with in large municipalities. We even did not have to purchase a liquor license from the town for our tasting room or sales room. Their answer was if the State and the Feds say your ok then so do we. Coop

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  • 1 year later...

Hi folks. I wanted to bump this thread as I've been looking at boilers and am a little confused.

In pricing out steam boilers, I'm finding that there's significant price differences between a home heating steam system rated to the same BTU's as a similarly sized commercial steam boiler. The numbers I'm being told are about $4,000 for a home system in the 150,000 BTU net output range and $10-12K for a 6 BHP commercial boiler (168,000 net BTU/h). The brands I'm seeing are Columbia, Burnham, Fulton. I'm looking for a steam boiler with a net capability of at least 130,000 BTU/h, so that's about 4 BHP, so practically a 6 BHP boiler is needed. All these prices don't include installation.

The prices don't include the return makeup water. Reading the earlier discussion tells me that something like that is really important.

But why the big price difference for the same amount of BTUs?

Another question is ignition: the commercial steam boilers I've looked at so far all seem to have electronic ignition. Some home heating steam boilers can be found that still use a pilot. Is there a specific reason for or against one or the other? Is a lag in the steam boiler in generating steam one of the difference in these systems? A home system can take it's time. An extra minute isn't going to cause the house to get cold. But would an extra minute be a problem in a distilling application?

Suggestions and comments welcome.

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  • 4 months later...

Thanks for the bump.

I got the commercial steam boiler, Columbia, 6 bhp. While a home heating steam system may have nominally the same BTU's the commercial equipment is better made an expects continuous operation, where a home system isn't geared towards that. With a commercial boiler you can control the pressure generated (much as Robert mentions in another thread). Further, you can use the gate valve at the boiler to regulate the flow of steam to your equipment so you're only using the steam you need.

I probably could have gotten by with a 4 bhp system, but am glad of the larger system. Will be able to add equipment without a boiler upgrade, if I ever get rich and famous.

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Glad this thread got bumped. I've been having a bit of issues with my boiler and I think it's time to call my boiler tech. When we are rectifying, I get a big change in flow rate depending on the steam pressure. Our boiler builds pressure until it reaches 11 PSI, then it starts its cycle once the pressure drops below 8 PSI. By the time the fan purges the air and goes through it's start up, the pressure has sometimes dropped to around 5 PSI.

So, I set my gate valve at a certain point but the steam is getting a 6PSI swing. I think I need to tighten up those settings, but I also don't want my boiler to run all day either. Maybe there's a low fire/high fire setting or something they can adjust.

Anyone have this problem before?

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