Rims/herms Hybrid Heating Chamber

[rwmingis]

Hi All,

I'm currently building a RIMs system. I chose RIMs as it will be nice and compact (good for a flat) and also so I don't have to deal with an extra container of hot water, etc. I know the advantages of HERMs vs RIMs, etc. What got me thinking was what if I did the best of both worlds, a hybrid RIMs/HERMs so to speak.

What I am thinking of doing is effectively making a HERMs but instead of using water as the filler medium to transfer heat between heating element and coil, use some sort of solid material instead. This would make it have the properties and benefits of a HERMs, but the ease of use and compactness of a RIMs.

Here's a couple sketches:

General Layout of heat exchanger:

Innards showing area to be filled:

The big question is, what to use as the solid filler? My first thought was lead. But that's heavy, and could melt if you had a meltdown. I suppose melting is not a big deal, but if what ever solid you had went to vapour, you'd be looking at a small bomb if you had a sealed container. I suppose I could leave a bit of a riser tube out the top and if the solid melted, it could just expand a few mm up the riser tube.

What ever material I use, it needs these properties:

1. High conduction coefficient (k)
2. Liquid at some point in it's life so that I can form it. Could be meltable like metal or cureable like glue.
3. Won't be too heavy like lead.
4. Definately won't vaporise as I might have a closed container.
5. I think it would be a good idea if it "wetted" to the element so that there is good heat conduction from the element. If it didn't make a good bond to the element, then there's a chance the element could get red hot since the heat would not be conducted away fast enough.

Well that's about it. If you guys have any thoughts for what kind of material to use, i'm all ears. For now, i'll build it as a RIMs system but eventually would like to trade out the heat exchanger to what we see here. I would use the same heating element (as shown)

Cheers!

Rob

 

[raven19]

Molten lead and possible poisioning all point to signs of danger for my 2c...

How about metal ball bearings? easy to pour into the voids... but lots of air gaps still... probably not a winner...?

Sounds like an interesting design though. Love hte 3D rendered piccies too.

 

[Adamt]

Save the fuss and go for water and implement a stirrer for further heat transfer by convection.

If you can get hold of some metal/oxide nanoparticles or some carbon nanotubes and disperse these into your thermal fluid, you can (increase) heat transfer considerably. (EDIT: Of course, be careful handling nanoparticles )

 

[Tim]

Sand is an obvious one

 

[chappo1970]

My 1st thought when reading the OP was if you have too much dense mass that can retain too much heat then you could or rather would have the problem of overshooting temps. You need the HERMS to initially overshoot the wort temp so that ramping times are minimal but not so much that you scorch the wort or denature the enzymes. Example a solid block of metal takes a lot longer to cool compared to a thin piece of sheet metal which I think would be the most challenging part.

I have had a thought about using oil as a medium in my HERMS. Much like the old school oil heater did but haven't done anything more than that sorry.

Lead would be a big no no in my book.

If you can get hold of some metal/oxide nanoparticles or some carbon nanotubes and disperse these into your thermal fluid, you can heat transfer considerably. (EDIT: Of course, be careful handling nanoparticles )

Here I'll reach into my pocket and pull some out for you as nanotubes are soooo easy to come by! h34r:

 

[Adamt]

Sand is an obvious one

Quartz thermal conductivity is only twice that of water, water would easily make up for that with convection effects.

 

[Supra-Jim]

If you can get hold of some metal/oxide nanoparticles or some carbon nanotubes and disperse these into your thermal fluid, you can heat transfer considerably. (EDIT: Of course, be careful handling nanoparticles )

nanotubes seem a good option, but they look expensive, does anyone have instructions for making your own nanotubes at home?

I think Chappo's suggestion of oil might be a good one. Inexpensive and very easy to work with.

Cheers SJ

 

[Adamt]

My 1st thought when reading the OP was if you have too much dense mass that can retain too much heat then you could or rather would have the problem of overshooting temps. You need the HERMS to initially overshoot the wort temp so that ramping times are minimal but not so much that you scorch the wort or denature the enzymes. Example a solid block of metal takes a lot longer to cool compared to a thin piece of sheet metal which I think would be the most challenging part.

I have had a thought about using oil as a medium in my HERMS. Much like the old school oil heater did but haven't done anything more than that sorry.

Lead would be a big no no in my book.



Here I'll reach into my pocket and pull some out for you as nanotubes are soooo easy to come by! h34r:

:lol: Nanotube-fluid suspensions for heat transfer fluids is part of my Masters research, I couldn't not suggest it :E

There's nothing better than water (within reasonable accessibility) as a heat transfer fluid when the temperature range of the system is below boiling point.

 

[Adamt]

nanotubes seem a good option, but they look expensive, does anyone have instructions for making your own nanotubes at home?

I was only being semi-serious! You won't be able to make and isolate them at home.

 

[LethalCorpse]

Mineral oil is commonly used as a heat-transfer fluid, though it has its own problems. Can go rancid over time, and condensation of water vapour can corrode things inside it unless it's completely sealed. Lead melts at 327C and boils at 1749C, so molten/vaporised lead wouldn't be a problem, but that highlights a problem for construction - how are you going to heat it to 350 and pour it in there. Ultimately, it's still dangerous stuff, and I wouldn't want it anywhere near my beer. Besides, Even though lead (or other metals) would have a much higher conduction coefficient than water, water gains an edge when you consider convection, particularly if you can create circulation for forced convection. I suspect you'll find that the RIMS system will perform much better than it ever would with a few layers of lead and copper between the element and the beer.

 

[chappo1970]

I was only being semi-serious! You won't be able to make and isolate them at home.

Pffft! Doesn't look that hard to make :unsure: You just need a really, really, really small pasta noodle maker. :lol:

@Adamt I had a chuckle at your original post.

 

[rwmingis]

Wow, some really good feedback already!

I hadn't even considered using particles like ball bearings or sand. Sand does sound like an option, but it may not 'wet' to the surface of the element well enough. But then again, it would work...

I had thought about oil as well, and it's still an option, but it only conducts heat at 1/4 the rate of water (ignoring convection etc), and it is still a liquid. My main goal is to keep away from something that needs a container as I don't have any room for a water chamber really anyway. I've got a base design (shown below), and really all i want to do on brew day is plug that sucker in and go. Don't want to worry about extra hoses for water bucket and cables to the heating element etc.

Here's my layout below:

I'm not overly worried about lead as the copper tubing will not have any joints inside the chamber, and it will 'wet' to the copper pipe. Not sure about wetting to the Incolloy element?

I don't think the thermal mass of a solid medium will be too much of a problem since most materials have a specific heat less than that of water. In fact, lead would be better than water really, as the same volume of lead will store just 1/4 the heat as water.

Where can I get these, how you say, nanotubes?

 

[Tim]

nanotubes seem a good option, but they look expensive, does anyone have instructions for making your own nanotubes at home?

I think Chappo's suggestion of oil might be a good one. Inexpensive and very easy to work with.

Cheers SJ

You can make your own nanotubes if you have access to apparatus that lets you do arc vapour disposition of graphite in an inert atmosphere. You can also make low quality multiwalled carbon nanotubes from hexachlorobenzene, but I can't tell you how as its a trade secret. I can sell you the know how though ! lol

My advice in regards to your heat exchanger is to not over-engineer your system. I think people get caught up in the shiny stuff and forget that you make good beer with a plastic bucket.

 

[Andyd]

Parrafin wax may be a good choice... although it's likely to scorch in contact with the element....

Nice rendering of your setup - what did you use for that?

Andy

 

[JonnyAnchovy]

You can make your own nanotubes if you have access to apparatus that lets you do arc vapour disposition of graphite in an inert atmosphere. You can also make low quality multiwalled carbon nanotubes from hexachlorobenzene, but I can't tell you how as its a trade secret. I can sell you the know how though ! lol

My advice in regards to your heat exchanger is to not over-engineer your system. I think people get caught up in the shiny stuff and forget that you make good beer with a plastic bucket.

Wrong! You need a flux capacitor!

 

[Thirsty Boy]

I suggest using a straight rims... but if you are interested in other heat transfer media.. then I think lethal corpse's mineral oil suggestion is a good one - or on the particle front, how about nice traditional copper, lots of little bits of it??

But once again - for the cost and trouble... you could get a nice custom low density element made up and do direct RIMS without all the intermediate stuff. I use an element out of a cheap kettle and don't notice all the bad things that are supposed to happen... a bit of cash for a purpose built LD element and I can't see even the possibility of an issue.

 

[MHB]

Have thought about something similar with SS tubes cast into a big block of Aluminium.

For a homemade jobbie Tin would be ideal, or for that matter Pewter, lots of old tankards at St Vinnie's and the like, melts around 200C (from memory), but can be melted in a SS saucepan on a domestic stove (either electric or gas).

If you acid cleaned all the surfaces and fluxed it should wet on really well to.

MHB

Edit
Just spotted the SI data Book, Tin melts at 232, Pewter is a fair bit lower.
M

 

[LethalCorpse]

lots of little bits of it??

Lots of little bits of anything - sand, ball bearings, copper shavings etc - will never be remotely as good as solid material. You just don't get enough heat transfer between the millions of tiny thermal interfaces, with attendant insulating air gaps.

 

[gregs]

What's wrong with air and a small gas flame? And a well insulated chamber.

 

[schooey]

Mineral oil is commonly used as a heat-transfer fluid, though it has its own problems. Can go rancid over time, and condensation of water vapour can corrode things inside it unless it's completely sealed.

Today's heat transfer and transformer oils are pretty well designed against thermal and chemical degradation, and also against sludging issues due to reaction with copper. They also have very good resistance to condensation and it's related problems. The big downer is, not many of them like being heated directly i.e. having an element immersed in them.

If you went with another tube inside the coil and put a ceramic style element in that, with a heat transfer oil in between, it would work very well