Mk-i

[WPStrassburg]

Can you get a 3/4" or 7/8" od rod/blanked off tube to go inside the 4 tubes inside the MK-I? That would minimize the wort volume inside the tubes and should create a higher velocity.

 

[leboeuf]

I've been lurking through this project and have to applaud the fab work!
Honestly I think your boil looks more vigorous with the copper coils because you're causing a more widespread state change from liquid to gas due to the increased surface area of the boiler (as in you can see it ).
The calandria focuses the heat on a much smaller volume of liquid.
It wouldn't surprise me if you're getting the same amount of heat transfer with the two techniques but you can only see it happening with the copper coils.

Based on your current results if you really want to cause the wort in the calandria test to move around you will need to increase the length of calandria to gain more temperature differential between the top and bottom (thus increasing fluid flow) or make the heat exchanger tubes smaller in diameter. (There's probably a trade-off in total amount of these smaller tubes )
My seat of the pants intuition tells me that your ratio of heat exchanger diameter to length is too high.

 

[klyph]

What's the typical length to width ratio of commercial caladrias and the boil vessel that contains them?

 

[GreenMonti]

Can you get a 3/4" or 7/8" od rod/blanked off tube to go inside the 4 tubes inside the MK-I? That would minimize the wort volume inside the tubes and should create a higher velocity.

Yes, I can. The tubes the MK-I is made from is 1". They're re-purposed dip tubes. I believe the ID of them is .970".

I've been lurking through this project and have to applaud the fab work!
Honestly I think your boil looks more vigorous with the copper coils because you're causing a more widespread state change from liquid to gas due to the increased surface area of the boiler (as in you can see it ).
The calandria focuses the heat on a much smaller volume of liquid.
It wouldn't surprise me if you're getting the same amount of heat transfer with the two techniques but you can only see it happening with the copper coils.

Based on your current results if you really want to cause the wort in the calandria test to move around you will need to increase the length of calandria to gain more temperature differential between the top and bottom (thus increasing fluid flow) or make the heat exchanger tubes smaller in diameter. (There's probably a trade-off in total amount of these smaller tubes )
My seat of the pants intuition tells me that your ratio of heat exchanger diameter to length is too high.

I would agree with the length issue. As Kladue has mentioned eairler, we are at a disadvantage with the use of a half barrel keg. In a sense we are just creating an air lift pump. Since I am not willing to increase the danger level and run the boiler at an increased pressure, I believe the wort spreader is out. Or at least this one. Maybe one of a different design could be implemented.
When comparing the MK-I to the copper coils, The MK-I has 20% less total surface area. That's if I count everything. The outside, the inner tubes, and the end plates since they are in contact with the liquid.
I don't know what to call it or maybe I am not relating what everyone is saying too it. I believe the MK-I has too much flow through it. The contact time is much too short. The only way I know of to dis-prove this is to run the coils again without the cylinder. This would prove that it was the heated input water and not the restricted flow the caused the difference in heating ability. I think it is flow due to the fact that the water tanks temp was low for quite a while.

What's the typical length to width ratio of commercial caladrias and the boil vessel that contains them?

That's a question for Kladue.


Thank you for the input guys.

 

[GreenMonti]

If I know the PSI that the propane is running at, and I know the diameter of the gas orifice. Can I tell just how much gas I am burning? I would like to know just how good or bad I am doing on the gas usage with my setup.

Kladue has brought up a really good point and a wonderful idea. I will be building a CFC and using it in reverse. It will go directly on the kettles out feed and I will then run the boiler feed water through it. This way I will see almost instant efficiency in the feed water to the boiler. No lag time waiting for the water tank to heat up.

I also wonder about water storage. I am willing to make RO/DI water for my boiler. However, I would like to only have to make it once or twice a year. Does anyone see a problem with me storing the boiler water in my tank if I make it a closed tank after operation?

 

[Mista_Sparkle]

If I know the PSI that the propane is running at, and I know the diameter of the gas orifice. Can I tell just how much gas I am burning? I would like to know just how good or bad I am doing on the gas usage with my setup.

Well, you would be able to if the valves were literally all the way open, otherwise you have some unknown amount of restriction so you will get a flow rate that depends on more than just the gas orifice and the psi of the tank

 

[kladue]

It should not be that hard to come up with a table for pressure vs. flow for a #56 drill orifice gas jet. Once I have the range I can check and see what size flow meter would be usefull to monitor gas flow.

 

[LooyvilleLarry]

Can't you just weigh the cylinder?

 

[Mista_Sparkle]

It should not be that hard to come up with a table for pressure vs. flow for a #56 drill orifice gas jet. Once I have the range I can check and see what size flow meter would be usefull to monitor gas flow.

flow meters are cheating

 

[kladue]

That is the low tech way, if water and fuel are metered then a better picture of capacity and efficiency can be had. I am interested in fuel flow to see if will be within the 20 SLM capacity of a mass flow controller.

 

[kladue]

There are a couple low range flowmeters in the northbound box, I have not done the calcs yet but should have the flow conversion information ready by the time they get there.

 

[MadWeezel]

If you are achieving the desired temps in the boil and are just concerned with flow through it, You could just use a march pump increase the flow...
(i have kept up with most of this thread, but i am lazy and havent read everything since page 11 so if this has been covered my bad.

 

[GreenMonti]

What I was hoping to do, was place a T fitting in line and check the gas pressure at the orifice. I haven't looked at it all yet, so I am not quite sure that will work. The idea was to measure the pressure at or close to the gas orifice so I would be able to tell what the actual pressure was running through it, regardless of where the regulator was set.

 

[kladue]

I have taken a look at an orifice chart for high pressure and after a couple calculations I figured out the BTU output and LP flow rates for various pressures. It looks like the flowmeters sent are a bit too small so I will look into aquiring correct size units for testing.

5 PSI LP......53614 BTU's...21.45 CFH...10.12 LPM
10 PSI LP....75822 BTU's...30.33 CFH...14.31 LPM
15 PSI LP....92863 BTU's...37.15 CFH...17.53 LPM
20 PSI LP..107229 BTU's...42.89 CFH...20.24 LPM
25 PSI LP..119886 BTU's...47.95 CFH...22.63 LPM
Flow was based on 2500 BTU/CF LP gas
PSI/BTU's were derived from #56 sized orifice chart
I hope this helps with input heat calculations for boiler

 

[GreenMonti]

I have taken a look at an orifice chart for high pressure and after a couple calculations I figured out the BTU output and LP flow rates for various pressures. It looks like the flowmeters sent are a bit too small so I will look into aquiring correct size units for testing.

5 PSI LP......53614 BTU's...21.45 CFH...10.12 LPM
10 PSI LP....75822 BTU's...30.33 CFH...14.31 LPM
15 PSI LP....92863 BTU's...37.15 CFH...17.53 LPM
20 PSI LP..107229 BTU's...42.89 CFH...20.24 LPM
25 PSI LP..119886 BTU's...47.95 CFH...22.63 LPM
Flow was based on 2500 BTU/CF LP gas
PSI/BTU's were derived from #56 sized orifice chart
I hope this helps with input heat calculations for boiler

I don't know what to do with any of that? LOL.

Can you tell me how many liters are in a 5 lb tank of LP? In its compressed form its liquid right? So, what does that turn into in a gas form?
What size hole will a #56 orifice have?
If I am able to get a pressure gauge at or near the orifice, will this give a more accurate reading on the gas usage?

 

[kladue]

The #56 orifice is the one sold with the 4" burners, with a pressure gauge in the gas line to the burner you can use the chart to see how much heat you are throwing at the boiler. 5 gallons of propane should be roughly 200 cubic feet of low pressure gas / 500K BTU's.

 

[GreenMonti]

The #56 orifice is the one sold with the 4" burners, with a pressure gauge in the gas line to the burner you can use the chart to see how much heat you are throwing at the boiler. 5 gallons of propane should be roughly 200 cubic feet of low pressure gas / 500K BTU's.

So running things at max fire i should be able to run the boiler for about 3 hours. If things are as I hope, then that would mean that I can run for 6 hours. Meaning I can brew for 2 ish bucks per session, running a 14 gallon boil. I wonder where the electric folks would fall in on this? IIRC the pol stated something like a 1.62 per run. However he was running 5-6 gallons batches.

 

[kladue]

A comparison of 5 gallons propane/electricity/NG
5 Gallons propane = 500,000 BTU's / 146 KWH
5 Gallons propane ~5 Therms NG /478 Cu Ft.

146 KWH @ $.06/KWH = $8.76
146 KWH @ $.08/KWH = $11.68
146 KWH @ $.10/KWH = $14.60

5 Gallons propane @$2.50/gallon = $12.50

5 Therms NG @ $.85 = $4.25

 

[diatonic]

A comparison of 5 gallons propane/electricity/NG
5 Gallons propane = 500,000 BTU's / 146 KWH
5 Gallons propane ~5 Therms NG /478 Cu Ft.

146 KWH @ $.06/KWH = $8.76
146 KWH @ $.08/KWH = $11.68
146 KWH @ $.10/KWH = $14.60

5 Gallons propane @$2.50/gallon = $12.50

5 Therms NG @ $.85 = $4.25

Yes, but typically with electric, the energy transfer is much more efficient than with propane or NG. My electric elements transfer most of those BTUs to the liquid they are heating, which I can't say about my propane.

 

[GreenMonti]

Yes, but typically with electric, the energy transfer is much more efficient than with propane or NG. My electric elements transfer most of those BTUs to the liquid they are heating, which I can't say about my propane.

How many watts are you using?
How big of batches do you do?
How fast do you hit a boil?

 

[Mista_Sparkle]

average heat transfer from a gas burner runs around 30-40%, in the boiler you may be at 60%. If its a traditional turkey fryer setup, you might only be at 20% so thats something to keep in mind. An electric element will probably transfer more than 95% into the wort, the rest being resistive losses elsewhere. So although a unit of energy in the form of propane or natural gas may be cheaper, the amount that you can use is much less. plus, as the water or steam heats up, the amount of useful energy decreases with nat gas or propane, whereas with electric, you can essentially get it as hot as you want untill the material properties of your element limit you.

 

[BrewBeemer]

A comparison of 5 gallons propane/electricity/NG
5 Gallons propane = 500,000 BTU's / 146 KWH
5 Gallons propane ~5 Therms NG /478 Cu Ft.

146 KWH @ $.06/KWH = $8.76
146 KWH @ $.08/KWH = $11.68
146 KWH @ $.10/KWH = $14.60

5 Gallons propane @$2.50/gallon = $12.50

5 Therms NG @ $.85 = $4.25

Where can you get 5 gallons of propane with those new filling valves with a fill limit shutoff float for only 3 1/2 gallon fills unless your refilling a larger tank?

Those KWH numbers posted;
That's cheap they're charging us $.21/KWH and i'm just one state below you, kind of sucks to be paying 70% more than the rest of the nation.
Adding insult to injury they're adding those "Smart Meters" around other surrounding cities with people complaining about their bills going instantly tripple or quadruple. Big investigation starting with the Feds on this.

 

[kladue]

Ah but we live with the curse of Bonnevile Power Administration in the northwest (single source cheap Hydro power), and the Portland G***** Electric utility company which serves my area, with less than desirable response to outages (3-5 days).
While electric systems are nice the practical limits on KW's available in residential service panels usually sets the 5.5 KW limit available by plugging into dryer outlets. Those that go up to a 50 amp source only reach the 9 KW range, still a major effort to get a heat source. A 5.5KW element should yield about 18,000 BTU's into the liquid, and the 9KW element should yield about 29,200 BTU's into the liquid.
With the calandria and condensate heat recovery the efficiency projection is about 80%+ on the boiler pending metered testing. With a nominal 100,000 Btu input there should be about 80,000 delivered to the liquid with the calandria. This seems to be a method that when set up correctly should be a high output single heat source for strike, sparge, step mash, and boiling functions in brewing like the large scale breweries do. Further refinement of the boiler and ancillary devices is ongoing, with a manually controlled system design coming first, then integration of the improved boiler and calandria into an automated system next.

 

[GreenMonti]

I ran the setup again today with the heat recovery in place. Still falling on the 40 min mark for the boil. That is starting again from 50*. I was able to run the boiler at 1 gallon/min and only have the fire at 1 full turn. The lower flame came after the water tank was at 200*. I also ran the MK-I today with out any mods, just straight up as it was built. I had a good solid boil. No need to change anything with the boil I had today. The spreader worked slightly for a while until the evap got down a little low. I will say that the spreader is very nice for keeping the boil in the kettle. The last few runs without it I was splashing the boil out of the kettle.

With the water tank in place for the recirculation of the waste water, I may or may not do the mods to the MK-I. It did very well today. All the surface area of the copper coils I didn't see any difference in the two methods. The boil and the fuel usage was the same.

How can one say that the efficiency of my boiler is around 30-40% or maybe 60%? I did scavenge my parts from a turkey fryer. I am far from a 20% though. Unless I did the math wrong or I just don't understand, I figure I am getting near perfect heat transfer. 12 gallons should need about 113,000 BTUs to get to boiling from 50*. After that you have about 97,000 BTUs for the boil. My burner is only rated by Brinkman to be 170,000 BTUs. If I understand things right this is all based on a BTU/Hour ratio. I am getting far more then the possible 60%. The nice thing about math is also works backwards. Look at my flow rate. Not the recent one of 1g/min but before when I was running 48oz/min with a 50* input.

 

[Mista_Sparkle]

well, 60% is just a guess. If you are getting perfect heat transfer, the hit exhaust gas from your boiler would be at the steam temp. You get a finite amount of heat available to transfer based on your mass flow rates of your working fluid, your propane, and any air that is also convected through your burner. Really I shouldn't even have said 60% unless were talking about second law efficiencies in which case the Btu's that are available to heat you water are also a variable based on your steam temps.

I think the best way to actually measure how "efficient" your setup is would be to measure the mass of gas used at a constant flow rate. That way you wouldn't need gas orifice sizes. If you are trying to calculate flow rates, most likely you are going to have other differences because of pipe constrictions as well. A flow meter would do the job, but measuring the mass of propane would seem to be much more accurate.

 

[GreenMonti]

So, 48oz/min is 2.66 gallons or 3.13lbs. Total heat per pound of water/steam at 5 psi is 1156.3 BTUs. That comes too 3619.21 BTUs/min.
12 gallons needs 113,456.5 BTUs from a cold start of 50* to boil.
At 3lbs/min it would take 31.34 mins to reach a boil in a perfect world.
I reach a light boil in 38mins and a hard boil in 42mins with the copper coils.
I reach a light boil in 35mins and a hard boil in 40mins with the MK-I.

Lets look at the long side of things at 42mins...that's 74.6% efficiency? Depending on when you start the clock...the 38mins gets me 82.4% efficiency?
The 35min mark gets me 89.5% efficiency.

I don't think this is bad considering I don't have an insulated steam line, or insulated vessels. If you don't use the 5 PSI from the start, since I don't build pressure for some time during the heating process. It bumps the time to boil to 31.5 mins. Which bumps the efficiency up from 75% to 90% depending on which one of the three boil times you want to use. Unless I am missing something here?

Until the actual flow rate of gas is figured out, this looks like a very good way to make beer. Far better then direct firing. IMO, also better then electric, due to the lack of the need for power or a trunk line running to your rig. My adjustable reg turns a half turn before the fire will even light....I ran a solid boil with the un-modified MK-I today with not even a full turn past the half. I was not even 1.5 turns on the regulator. I had bubbles, rolling liquid, the whole nine.

I am not looking to argue with anyone here, its just my first time with any of this stuff and I want to make sure I understand it. I have learned a ton about this. I want to learn more, but I want to learn it right.

 

[GreenMonti]

well, 60% is just a guess. If you are getting perfect heat transfer, the hit exhaust gas from your boiler would be at the steam temp. You get a finite amount of heat available to transfer based on your mass flow rates of your working fluid, your propane, and any air that is also convected through your burner. Really I shouldn't even have said 60% unless were talking about second law efficiencies in which case the Btu's that are available to heat you water are also a variable based on your steam temps.

I think the best way to actually measure how "efficient" your setup is would be to measure the mass of gas used at a constant flow rate. That way you wouldn't need gas orifice sizes. If you are trying to calculate flow rates, most likely you are going to have other differences because of pipe constrictions as well. A flow meter would do the job, but measuring the mass of propane would seem to be much more accurate.

So what do you suggest, Should I weigh the tank before and after a run?

 

[diatonic]

How many watts are you using?
How big of batches do you do?
How fast do you hit a boil?

I should have some hard numbers in about 2 weeks. Finishing up my hybrid propane/electric rig. I'm going to do the first brew on it firing the HLT with a banjo burner @ 10-15psi. I'll gather hard data on how long it takes to heat. The next batch will be heating the HLT with a 240v/5500w element. I should be pushing it with 220V which I think will give me 4622W... which should be 15,770 BTU. Will see how it compares.

EDIT: My previous statement about my electric being more efficient was based on my old rig.

 

[Mista_Sparkle]

Yeah, I would think that the best way to determine your actual gas usage would be to weigh the tank before and after your burn, if you could throw it on a scale and take measurements every 10 minutes or so, you could get a better picture of your usage as the tank cools and therefore your flow rate changes.

I am not saying that this is a bad rig at all, compared to standard methods, this is great. It really isn't fair to compare to electric because of the different qualities of each heat source.

If you do weigh the tank, you will need a somewhat accurate scale, probably with a resolution of less than an ounce, but if you have something around to do this with, you will have far fewer variables to account for in a flow calculation.

If you want to talk about efficiencies in terms of cost, that's a very valid measure, so are thermal efficiencies, there are a couple other measures of efficiency as well.

If you want to talk about efficiencies, keep in mind that most good power plants have 1st law efficiencies of around 40% and second law efficiencies of around 90%. Where second law efficiencies are based on possible heat transfer as opposed to total energy transfer.

 

[kladue]

After looking at the test run results and doing some calculations it appears that the heat transfered with the steam system is nearly 10 times the expected output of the 4 KW electric element. While this heating system approach is not for everyone it appears to be a viable way for a DIY'er to build a system with a single heat source that will give results that are beyond the reach of the current electric systems. With a bit of engineering and design work this could be integrated into a brew system to handle strike water heating, step mashing, sparge water heating, and finally boiling. Scalability of this boiler and calandria design would make it a viable heating system for the 55 gallon drum systems that need more heat than direct fire burners can easily provide. With the ability to heat water to strike at 2.5+ GPM with current design, and deliver 156.9K BTU's/hr to the water for boiling it almost is overkill on 1/2 barrel systems.

 

[BrewBeemer]

After looking at the test run results and doing some calculations it appears that the heat transfered with the steam system is nearly 10 times the expected output of the 4 KW electric element. While this heating system approach is not for everyone it appears to be a viable way for a DIY'er to build a system with a single heat source that will give results that are beyond the reach of the current electric systems. With a bit of engineering and design work this could be integrated into a brew system to handle strike water heating, step mashing, sparge water heating, and finally boiling. Scalability of this boiler and calandria design would make it a viable heating system for the 55 gallon drum systems that need more heat than direct fire burners can easily provide. With the ability to heat water to strike at 2.5+ GPM with current design, and deliver 156.9K BTU's/hr to the water for boiling it almost is overkill on 1/2 barrel systems.

But perfect for a 1 barrel brewing system, why not expand?
What a great thread to follow keep those replies coming.

 

[kladue]

This is GreenMonti's wort heating creation, scalability of both boiler and calandria style wort heater to fit larger applications will not be a big factor if he decides to head that direction. It looks like I will be switching from SS coils to copper coils in the automated system to improve on the dismal 25% heat transfer with SS tube boiler after last live testing run data was calculated.
Not sure why you would want to make 30-50 gallons of the same beer at a time, I would rather make 6-10 different beers with same amount of ingredients and less effort. With a brother inlaw that makes SS tanks, scaling up tankage and plumbing is not a challenge, just have not seen a need to build larger, would rather make it more like a Rube Goldberg automated machine.

 

[BrewBeemer]

This is GreenMonti's wort heating creation, scalability of both boiler and calandria style wort heater to fit larger applications will not be a big factor if he decides to head that direction. It looks like I will be switching from SS coils to copper coils in the automated system to improve on the dismal 25% heat transfer with SS tube boiler after last live testing run data was calculated.
Not sure why you would want to make 30-50 gallons of the same beer at a time, I would rather make 6-10 different beers with same amount of ingredients and less effort. With a brother inlaw that makes SS tanks, scaling up tankage and plumbing is not a challenge, just have not seen a need to build larger, would rather make it more like a Rube Goldberg automated machine.

And I know you will. Once I get hooked on a bier I like I do not get tired of drinking it besides the friends that help me so large batches go rather quickly.

Did I mention the ELS-950 level sensor in a PM that's rated at 40 mA sink up to 30 VDC for only $65 plus up to 230*F? Have a great week plus be safe. Carl.

 

[kladue]

I think that the washing machine level switch would be a slick way to get adjustable level control with a line voltage set of contacts, cheap and wet connected.

 

[sativen]

So, 48oz/min is 2.66 gallons or 3.13lbs. Total heat per pound of water/steam at 5 psi is 1156.3 BTUs. That comes too 3619.21 BTUs/min.
12 gallons needs 113,456.5 BTUs from a cold start of 50* to boil.
At 3lbs/min it would take 31.34 mins to reach a boil in a perfect world.
I reach a light boil in 38mins and a hard boil in 42mins with the copper coils.
I reach a light boil in 35mins and a hard boil in 40mins with the MK-I.
.............

Someone correct me if I'm wrong here, but I think your numbers are off.

Shouldn't it take 16135.2 BTUs from a start of 50 degrees?
(12 gal * 8.3 lb/gal * 162 degrees) = 16135.2 BTU.

Or is my formula wrong?

 

[kladue]

Your formula is correct for the heating of water to 212 degrees, it is the additional 970 Btu's/Lb to reach a boil that you overlooked. Most times the number used for water is 8.45 Lbs/Gallon for cold water, 8.3 is close enough for this application. Heating the water to 212 usually takes 15% of the total energy needed, the other 85% is needed to make it boil.

 

[Mista_Sparkle]

Someone correct me if I'm wrong here, but I think your numbers are off.

Shouldn't it take 16135.2 BTUs from a start of 50 degrees?
(12 gal * 8.3 lb/gal * 162 degrees) = 16135.2 BTU.

Or is my formula wrong?

your formula is "right" but it doesnt account for any external heat transfer or evaporation. If it was perfectly insulated, thats is about what you would get.

However, i have the feeling that this rig dumps a quite a bit of heat throughout.

 

[sativen]

Your formula is correct for the heating of water to 212 degrees, it is the additional 970 Btu's/Lb to reach a boil that you overlooked. Most times the number used for water is 8.45 Lbs/Gallon for cold water, 8.3 is close enough for this application. Heating the water to 212 usually takes 15% of the total energy needed, the other 85% is needed to make it boil.

I understand about heat losses, efficiency, etc, but help me out with the rest of the BTUs per lb.

Isn't the remaining 970 BTU/lb only if you were boiling all that water off into steam? Or are you saying that going from a 212 degree standing water to a 212 degree rolling boil takes the additional 970 BTU/lb?

Thanks.

 

[diatonic]

I understand about heat losses, efficiency, etc, but help me out with the rest of the BTUs per lb.

Isn't the remaining 970 BTU/lb only if you were boiling all that water off into steam? Or are you saying that going from a 212 degree standing water to a 212 degree rolling boil takes the additional 970 BTU/lb?

Thanks.

The latent heat of vaporization for water at the boiling point is 2260 kJ/kg.

convert 2260 kJ/kg (kilojoules per kilogram) to British thermal units per pound.. 971.6 BTU/lb (British thermal units per pound).

So, the latent heat required to get water at the boiling temperature to steam, without an increase in the temperature, is 971.6 BTU/lb of water.

I think

EDIT: There is some good info on Wikipedia about latent heat.

 

[kladue]

The 970 Btu's /Lb gets the water to a point where additional energy applied trys to escape as steam causing the boiling effect. With the larger volumes of liquid in the kettles the heat applied tends to spread out, that is one of the reasons it takes the time to reach a boil when you have to apply 970 btu's/Lb to all of the liquid before steam bubbles start to form. The bubbles that start to show at lower temperatures are the dissolved gasses in the liquid forming bubbles as the solubility of gasses in water drops with increasing temperature.