Flash boiler project #2

[ScubaSteve]

I think the act of recirculating while heating will really make a difference. I plan on doing an experiment and seeing if it's quicker to fill slowly directly from the boiler or to just fill the hlt and recirc while the boiler is heated.

I just had a thought.....if you're a guy like me having problems with the deadspace in the center of the coils, what if you stuck something in there? a 3" piece of ducting with a cap pointing down....to redirect the heat to the sides and out if the center? The heat should come more in contact with the coils that way.....and you could probably turn the burner down too.....

 

[Bobby_M]

The heating time would be the same but you'd be able to regulate the temp more easily.

If you're using tap water input, the only way to regulate the output temp is either flame control (hard to do via automation) or flow control (also not the easiest thing to do). If you fill your HLT and recirc through the flash boiler, you could cut both the gas flow and pump as soon as you reach your desired temp with one simple on/off controller.

 

[monty73741]

hmmm.......this could be done also with an old gas grill. just put the coil horizontal...

 

[ScubaSteve]

All very true. In another post, you made the point that inline heating is quicker, i.e. a 0.5 gpm flow rate would heat 5 gals in 10 mins. vs. the 45 mins we see with bulk heating. That seems to make sense to me.

One concern I have is the thermal mass of the water...a small amount of heated water trickling into an unheated keggle is gonna drop in temp quickly. Maybe if you dumped a gallon of hot tap water in first to preheat, you could counteract this.

 

[ScubaSteve]

hmmm.......this could be done also with an old gas grill. just put the coil horizontal...

Probably, but there's something to be said for heat rising all the way past the coil in a vertical fashion...like a CFC but in reverse....

 

[jezter6]

I think, though, that having a flat grill flash heater that sits on an already useful piece of equipment DESIGNED to keep heat and heat all around the area --- it's like an Alton Brown "multi-tasker" - you can turn off the water then cook burgers, then turn the water back on.

 

[ScubaSteve]

That's a good point.....for that matter, you could FSR402's original design with the charcoal chimney starter. Install the coil, fill that sucker to the brim with charcoal, and fire it up! Charcoal briquets get up to 800F in some places.....you could definitely heat 10 gallons of water with a full chimney. You could probably still install ducting at the top to address the venting issue. Charcoal's pretty cheap too....you'd probably get at least 5-10 brews out of a $5 bag of the cheap stuff.

 

[jezter6]

That's a good point.....for that matter, you could FSR402's original design with the charcoal chimney starter. Install the coil, fill that sucker to the brim with charcoal, and fire it up! Charcoal briquets get up to 800F in some places.....you could definitely heat 10 gallons of water with a full chimney. You could probably still install ducting at the top to address the venting issue. Charcoal's pretty cheap too....you'd probably get at least 5-10 brews out of a $5 bag of the cheap stuff.

That or use the propane grill, then you have hot dogs going on the upper rack while water is heating in the lower rack.

 

[ScubaSteve]

You could do that, but my concern is that simply laying a coil on the grate isn't as much focused, intense heat as placing it into a chimney with red hot coals or a burner with direct heat. The burner on a propane grill is probably much lower BTU's than a turkey fryer burner, too...

 

[FSR402]

All very true. In another post, you made the point that inline heating is quicker, i.e. a 0.5 gpm flow rate would heat 5 gals in 10 mins. vs. the 45 mins we see with bulk heating. That seems to make sense to me.

One concern I have is the thermal mass of the water...a small amount of heated water trickling into an unheated keggle is gonna drop in temp quickly. Maybe if you dumped a gallon of hot tap water in first to preheat, you could counteract this.

That's an easy fix, fire up the burner under the Kettle/HLT just enought to over ride the heat loss.

 

[jezter6]

You could do that, but my concern is that simply laying a coil on the grate isn't as much focused, intense heat as placing it into a chimney with red hot coals or a burner with direct heat. The burner on a propane grill is probably much lower BTU's than a turkey fryer burner, too...

True, I guess it depends on what's more important - efficiency of propane or speed. If you're looking to multi-task and cook food at the same time, you can throttle back the water speed and while it will take longer than the chimney column, it's may end up faster than the stove or full pot on the burner and still cook using propane you were using for the food anyways, saving you some $.

if you want super fast super efficient - then yes, I see your point. All depends on what you want out of it.


Since we're comparing this to cooling products, I see potential in a reverse plate chiller. You blast major heat on the many many plates while pushing liquid through, and voila - it sits nice and flat and might be ultra efficient if you encase it in some sort of box maybe?

It would be interesting to at least test if anyone has a plate chiller that is deemed not safe for wort but can still be used as a test device to see how fast water can heat up in it.

 

[FSR402]

True, I guess it depends on what's more important - efficiency of propane or speed. If you're looking to multi-task and cook food at the same time, you can throttle back the water speed and while it will take longer than the chimney column, it's may end up faster than the stove or full pot on the burner and still cook using propane you were using for the food anyways, saving you some $.

if you want super fast super efficient - then yes, I see your point. All depends on what you want out of it.


Since we're comparing this to cooling products, I see potential in a reverse plate chiller. You blast major heat on the many many plates while pushing liquid through, and voila - it sits nice and flat and might be ultra efficient if you encase it in some sort of box maybe?

It would be interesting to at least test if anyone has a plate chiller that is deemed not safe for wort but can still be used as a test device to see how fast water can heat up in it.

With the testing of my FB I have found that it's a fine line from 180 to boiling. With the copper tubbing it does not bother me but will a plate chiller handle that?
I'm sure the inside will but will the outside handle the flame heat?

 

[jezter6]

With the testing of my FB I have found that it's a fine line from 180 to boiling. With the copper tubbing it does not bother me but will a plate chiller handle that?
I'm sure the inside will but will the outside handle the flame heat?

I've only seen plate chillers at the store, never really looked hard at them. Theory could be pretty sound though, which is why I said someone who has a spare/semi-broken one to test one --- I would never advocate screwing with a nice working plate chiller.

If it wouldn't handle the direct flame, what about a "chiller in a box" kind of concept. Something like an iron box that the plate chiller sits inside. The box takes the direct flame but transfers indirect heat and traps it inside a box where the plate chiller would be?

 

[conpewter]

Just go with a cold plate sitting on your grill for an easy way to do this, otherwise I like the idea of charcoal, or even make one of these things to put over your firepit to use free firewood to heat with.

 

[jezter6]

Just go with a cold plate sitting on your grill for an easy way to do this, otherwise I like the idea of charcoal, or even make one of these things to put over your firepit to use free firewood to heat with.

Which brings to mind the charcoal in the chimney idea -- what about a good heap of charcoal on the plate chiller? Sort of like a good ol' dutch oven on the campfire.

 

[Bobby_M]

All very true. In another post, you made the point that inline heating is quicker, i.e. a 0.5 gpm flow rate would heat 5 gals in 10 mins. vs. the 45 mins we see with bulk heating. That seems to make sense to me.

One concern I have is the thermal mass of the water...a small amount of heated water trickling into an unheated keggle is gonna drop in temp quickly. Maybe if you dumped a gallon of hot tap water in first to preheat, you could counteract this.

I look at this flash heating thing whether it's gas fired or electric heating element based as an HLT replacement actually unless you're going to use it as a HERMS exchanger.

If you're using it to heat strike water, I'd use an output temp based on known MLT heat losses from the vessel and grist size/temp just like you would if you were bulk heating in an HLT.

Even though I'm nowhere near ready to build it, I'm still leaning toward electric due to its ease of regulating via PID for more exacting temp output. Again, I could be talking out of my a$$ since I'm not ready to build yet and haven't invested enough time into researching it.

 

[ScubaSteve]

I've only seen plate chillers at the store, never really looked hard at them. Theory could be pretty sound though, which is why I said someone who has a spare/semi-broken one to test one --- I would never advocate screwing with a nice working plate chiller.

If it wouldn't handle the direct flame, what about a "chiller in a box" kind of concept. Something like an iron box that the plate chiller sits inside. The box takes the direct flame but transfers indirect heat and traps it inside a box where the plate chiller would be?

https://www.homebrewtalk.com/f11/plate-chiller-herms-58747/

 

[FSR402]

I think if you were only going to pump clean water thru the coldplate it would work great but pumping wort thru would be bad.

Once I have this thing done and built into the rig I'm going to have to get a pump and use ut also for a HERMS and to help speed up the wort boil.

 

[ScubaSteve]

Yeah, I don't know....I think the cold plate is probably ok at cold temps, but who can say what's inside? There's probably some gaskets/seals that might melt.

Does anyone know the cheapest place to find ss tubing? McMaster seems to be around $55 for 50' of 1/4". Or, would 3/8" be better?

I like the idea of running wort thru as a step mash, but you'd really have to keep the burner down.

 

[talleymonster]

Are you dead set on SS, ScubaSteve? The reason I ask is because 50' of 3/8 copper is only 32.90$ plus shipping @ CopperTubingSales.com :: ICS Indsutries ::

 

[kladue]

With the setup I have the boiler output feeds the mixer then on to the sparge ring in the mash tun. This way it sends strike water to mash tun without circ pump, fire circ pump and mix steam into wort for step heating, switch pump to fill boil kettle and run sparge water through mixer again to clean and fly sparge without changing connections.

 

[ScubaSteve]

With the setup I have the boiler output feeds the mixer then on to the sparge ring in the mash tun. This way it sends strike water to mash tun without circ pump, fire circ pump and mix steam into wort for step heating, switch pump to fill boil kettle and run sparge water through mixer again to clean and fly sparge without changing connections.

I guess i don't understand your use of the term "mixer"....?

 

[ScubaSteve]

Are you dead set on SS, ScubaSteve? The reason I ask is because 50' of 3/8 copper is only 32.90$ plus shipping @ CopperTubingSales.com :: ICS Indsutries ::

Oh Snap! That's a good deal! I wasn't set on SS, but I got tired of putting crimps in the copper because it was so soft. I figured I might be able to get ss and do tighter coils.

SO....I was thinking about simplifying Kladue's design and just doing two interlaced coils...and instead of a 4 way splitter at top/bottom, I'd just use tees. If I had 50', I could cut the coil into two equal pieces. I figure 3/8' copper ought to provide a nice ratio of gpm and heat transfer....

Question....at the tees, what size would be good? Should I stay with 3/8", or should I go up to 1/2" since I'd effectively have 2 lines (the coils) in 3/8"?

 

[kladue]

Here is a picture of the new wort/steam mixer Picasa Web Albums - Kevin - New system st... steam/hot water enters through check valve on right side, wort through center of tee, steam and wort mix in tube and exit through left hand tee. Only have operating information on old system as new system is waiting for software completion to begin operation. Here is a shot of the old system control panel in a max boiler output test Picasa Web Albums - Kevin - Flowmeters wort into mixer 130 deg F, Steam into mixer 292 deg F., mixed wort out temp 166 deg F. at 50 GPH (.8 GPM) wort flow. The mixer has a 2" long 1/4" od SS screen wire diffuser to keep steam bubbles small when they hit liquid so it is fairly quiet in operation, a sizzling sound as steam bubbles collapse is normal at high steam temp/flow.

 

[ScubaSteve]

Wow. That's awesome. Out of my price range, definitely something I would never have thought of myself.....but awesome.

I think it's cool that you CAN step mash wort...but I want to focus on heating the hell out of some water in a quick fashion. I'd like to have my HLT filled with about 8 gallons of 190F water in 15 mins. If I can achieve that in a small package, I think I might have broken the "HLT Barrier" in brewing with my rig. I brew tomorrow....I'll test the properties of the jury-rigged prototype, take pics (beer porn :rockin then next paycheck I'll consider getting new copper, fittings, etc. (if this one sucks) and chop my corny.

I'm convinced 6" is probably gonna be too small for a chimney.

 

[kladue]

All the mixer parts could be made with brass or copper parts from hardware store, the mixer screen could be brass screen, or one could drill a bunch of small holes in the tube to spread steam out . The idea of injecting steam into liquid was a copy of industrial unit for starch cooking in the paper industry, just scaled down to homebrew system size. If one recirculates the wort in the mash tun, the steam injection system offers a way to get much more heat into the wort without carmalization on hot surfaces, and the ability to control temperatures for repeatability. With a 6 gallon batch the old system will raise temp from 130 to 152 deg F. in 10-12 minutes with mixed wort temp of 152 to mash tun. As to the size of the chimney here is a shot of the new boiler with 6" tube, 4-20' coils of 1/4" SS tube, and a 4" hurricane burner underneath.http://picasaweb.google.com/kevin.ladue/NewBoilerAndMixer#5244098716185213058

 

[kladue]

If one has a flash boiler why would you need a HLT any more?, just heat the water as needed.

 

[ScubaSteve]

If one has a flash boiler why would you need a HLT any more?, just heat the water as needed.

Yeah. You got yourself a point.

 

[ScubaSteve]

All the mixer parts could be made with brass or copper parts from hardware store, the mixer screen could be brass screen, or one could drill a bunch of small holes in the tube to spread steam out . The idea of injecting steam into liquid was a copy of industrial unit for starch cooking in the paper industry, just scaled down to homebrew system size. If one recirculates the wort in the mash tun, the steam injection system offers a way to get much more heat into the wort without carmalization on hot surfaces, and the ability to control temperatures for repeatability. With a 6 gallon batch the old system will raise temp from 130 to 152 deg F. in 10-12 minutes with mixed wort temp of 152 to mash tun. As to the size of the chimney here is a shot of the new boiler with 6" tube, 4-20' coils of 1/4" SS tube, and a 4" hurricane burner underneath.Picasa Web Albums - Kevin - New Boiler an...

How long is your chimney? Seriously though. Looks like you curved some ss sheet and welded it. I'd like to be able to keep the height right about that of a sanke. I think they're 24" or so....

 

[FSR402]

If one has a flash boiler why would you need a HLT any more?, just heat the water as needed.

You can but how would you know how much you are heating? I don't have gallon marks in my MLT. Plus it's a little touchy as to what the temp is coming out at. So I want o use my HLT as a holding tank that I can also use to adjust the water temp if needed.
If you are just going right from the FB to the tun and you under shoot the temp, what are you going to do about it?