Using prop glycol to water jacket heat all other vessels

[benjii]

I'd like to design a system that has one boiler that drives the heat of all other vessels (HLT, MLT and Kettle) by pumping hot prop glycol through coils around the pots. Does anyone know of the best/easiest DIY way of achieving good heat transfer? Has anyone tried, or am I just a mad man?

 

[OzPaleAle]

I'd like to design a system that has one boiler that drives the heat of all other vessels (HLT, MLT and Kettle) by pumping hot prop glycol through coils around the pots. Does anyone know of the best/easiest DIY way of achieving good heat transfer? Has anyone tried, or am I just a mad man?

Would probably have to be careful how you heat the boiler vessel, not sure if you have an element in direct contact with prop glycol if you would heat it enough to create a smoke machine.
Smoke machines used in concerts etc use a prop glycol\water mix as the fluid and is heated to something around 200C to vaporise it. Probably not going to get to that temp in your system but worth keeping in mind unless you get some lasers and strobes and do some disco brewing.

 

[SNippets01]

I'd like to design a system that has one boiler that drives the heat of all other vessels (HLT, MLT and Kettle) by pumping hot prop glycol through coils around the pots. Does anyone know of the best/easiest DIY way of achieving good heat transfer? Has anyone tried, or am I just a mad man?

If you have a closed loop for your heating system, why not have them immersed in the fluid? That would be much better for heat transfer (more direct contact).

Having multiple layers between the heating fluid (coil, air space, metal jacket or vessel wall) will add resistance to the heat transfer (and efficiency of heating/cooling). This may also remove the need to use prop glycol and just water instead, but as with any heating medium you need to be careful of what pressures you may expect in your system and design your piping and fittings accordingly.

 

[MHB]

It might sound like a good idea, and it might even be a good idea - but don't go there.
To get enough heat transfer all your vessels are going to need to be jacketed, pressure rated and made to extremely high standards - and come at a gold plated price.
If you were serious about this idea you wouldn't be using Glycol just pressurised hot water - it has much better heat carrying capacity - the problem is that if you get a leak in a high pressure hot water circuit, it would be like taking the lid off a working pressure cooker, you get instant flash boiling and what could easily be a steam explosion, sort of thing I would rather watch from a distance than up close and personal injury...
Low pressure steam would be much safer and more manageable, tho that's not without its risks to, this type of heating is better left for the biger brewers I mean 10HL and above, for smaller plants it isn't worth the investment, maintenance and risk.
Mark

 

[benjii]

If you have a closed loop for your heating system, why not have them immersed in the fluid? That would be much better for heat transfer (more direct contact).

I'd like a closed loop, however to immerse the pot in the liquid i'd have to build a sealed jacket which not sure I'd be able to do easily, especially with fittings etc poking out of each one.

 

[benjii]

It might sound like a good idea, and it might even be a good idea - but don't go there.
To get enough heat transfer all your vessels are going to need to be jacketed, pressure rated and made to extremely high standards - and come at a gold plated price.
If you were serious about this idea you wouldn't be using Glycol just pressurised hot water - it has much better heat carrying capacity - the problem is that if you get a leak in a high pressure hot water circuit, it would be like taking the lid off a working pressure cooker, you get instant flash boiling and what could easily be a steam explosion, sort of thing I would rather watch from a distance than up close and personal injury...
Low pressure steam would be much safer and more manageable, tho that's not without its risks to, this type of heating is better left for the biger brewers I mean 10HL and above, for smaller plants it isn't worth the investment, maintenance and risk.
Mark

I didn't want to go steam for this exact reason. Too dangerous. I'd prefer an unsealed boiler pumping liquid around the place, which is essentially what we do with wort already.

 

[QldKev]

I wish there is an easy way. I've love to have a steam jacketed vessel setup it would make life easier. Listen to Mark's caution about pressurized boiling fluids and flash boiling, my brother has the scars to prove it. I think on our scale the initial cost makes it unfeasible, but hopefully someone has an awesome idea and makes that statement untrue.

I do have a reverse HERMS idea I just chucked up for discussion. This could help.

 

[SNippets01]

I'd like a closed loop, however to immerse the pot in the liquid i'd have to build a sealed jacket which not sure I'd be able to do easily, especially with fittings etc poking out of each one.

Sorry if i wasn't clear before, I was meaning something like a coil immersed into the water/wort/mash. Heat from within rather than from outside.

 

[booargy]

takes a lot of energy. not enough use to give a good feedback yet.
This is a mash tun/boiler I have been working on. a cut off keg is welded to the chime. the tri-clamp ferals are for punkins element enclosures. it is loud and takes a long time to heat. I plan on giving it a run with peanut or olive oil this should give a higher differential temp.

 

[MHB]

No problems using a pumped working liquid for heating the HLT and the mash tun, where you will have a world of hurt is trying to get enough heat into the kettle to achieve a boil, without the working fluid being a lot hotter than 100oC.
Steam achieves this by using the energy involved in the phase change, water systems by using pressure to raise the boiling point, either which way you need to be working with something that is inherently dangerous.
Using a fluid with a higher BP to carry heat is in theory possible but in practice is very hard to achieve - again with in the confines of reasonable expense and while staying fairly safe - most of the liquids like Glycol aren't all that good at carrying heat, there are silicone fluids (expensive) and things like oils but organic oils will break down fairly rapidly and cause a lot of build-up on surfaces that leads to rapid loss of efficiency.

Industry has spent a lot of time and money on this type of idea, Steam and High Pressure Hot Water - with all the known issues - are the simplest and best options available and they are really outside the practical working grasp of a home brewer.
Mark

 

[pk.sax]

That is quite confronting that the industry hasn't found a good working solution besides steam/hp water at their level of interest. I reckon a braumeister or a 1v internal rims-ish setup is the process solution to the the question, i.e., instead of using a fluid that changes phase to transmit the heat, use a solid element that can be directly heated by passing a current through it/element filament. It's the whole, why make the heat flow when you can make the fluid to be heated flow argument.

 

[booargy]

I never thought of the carbon build up from the oil is will act as an insulator. But won't this only happen at the smoke point of the oil? MHB is right about it being no good for a kettle but as a boiler for my use max temp needed is about 90c.