RIMS Tube = Pipe bomb?

[horseinmay]

TallDan,

I don't mean steam jacketed, but actually using the pressure in the chamber with the element to inject steam into the wort as it flows through the rims. There is no need for surface area contact, just let the wort recirculate, and the steam will go into that stream and condense, releasing its heat energy. All he would have to do is puncture the pressure chamber and make some minor changes.

 

[sablesurfer]

Thank for your reply PushRod. I was thinking about salvaging my creation with a pressure relief valve. Aside from that I was going to put the silly thing in an enclosure to isolate myself and others from potential harm.

LOL...now I am envisioning the MythBusters trying to brew from behind their blast shield.

(HAHA...now that I have read whole thread, I am not the only one.)

Don't let the doubters get you down, I learned something from this and went, "oh yeah" while I was still trying to figure what you were attempting.

((As for a 'what the hell did I just do?!?!' moment in my life...at a backyard fireworks party with some SERIOUS planners, I put a random bottle rocket into a tube, lit it, launched it. ONLY THEN did I realize I had used a MORTAR tube from the FINALE portion of the night to launch my pissy little moon rocket from....to this day I think..."OMG"

 

[ajwillys]

I personally think this is a pretty decent idea but with a fatal flaw. No need to re-hash, it's been covered. I would just make a "stovepipe" type thing that sticks out vertically and attaches to the inner tube. You could use it to fill/empty the inner reservoir and would allow for the necessary expansion.

This is a HERMS not a RIMS. HERMS exchange the heat, RIMS immerse the heat. I had considered making something not totally different from this except it was more like a paint can with an element and a copper coil wound inside. It was open though, not closed.

 

[Hamaki]

I thought about the open ended idea too; safe but won't heat above 212 F at 1 atm so you'd need the surface area ajwillys describes for adequate heat transfer...essentially a herms design. If the inner chamber were filled with another fluid with an extremely high boiling point, like say mercury, now then you'd have something...probably brain damage or kidney failure.

Rims with ULWD element and a reliable pump should prevent scorched wort. Herms and an unreliable pump would not result in scorched wort. I don't know squat about steam injection but you can search steam infusion mash systems (SIMS) on this forum for more info.

 

[VladOfTrub]

A copper packless K wall, vapor to liquid heat X max working pressure on the shell is 650 pounds at 100F. The transfer side 400 pounds at 100F. In your Rube Goldberg design, the superheated water is sealed inside of a tube, inside another tube. If the inner tube ruptures, the release of energy into the wort side might rip the plastic transfer tubing you may be using, out of the kettle, spewing hot wort. The outer shell won't rupture. The open tubing becomes the relief device for the outer shell. The soft soldered joints or the fusite on the element will blow before the copper. If you used M wall, the copper may fracture, due to expansion/contraction of the thin wall. The element isn't designed to operate at superheated temps and high pressure. Superheat is the temp of a liquid above its boiling point. Water at 213F has one degree superheat. Superheat is part of a pressure thing. When superheated water changes state, kind of what would happen if a rupture occurs. A lot of energy is released. A BTU is 1 lb of water raised 1 degree, until the point of change of state.

You are right, we learn from mistakes. Only, if we survive. If we don't survive, others learn from the mistake.

 

[brew_ny]

You are right, we learn from mistakes. Only, if we survive. If we don't survive, others learn from the mistake.

truth to that

 

[bajaedition]

truth to that

Yeppers sure is

I think we can all look back at stupid mistakes we almost did not survive

but before you are old and wise you had to survive young and dumb

 

[VonRunkel]

Mechanical engineer here:

To mathematically/thermodynamically tell you why this is a bad idea we can assume the water inside the pressure vessel is ideal. And while it isn't exactly the right law to use, it will suffice to use the ideal gas law== PV=RT, with R being the universal gas constant.. essentially you can change any two of the three variables and it will fix the third.

In this case you have a fixed volume with a variable temperature, which will fix your pressure, BUT the temperature is changing so your pressure will change proportionally. This is where you may reach your pressure threshold and cause an explosion.

My solution would be to install a reservoir vented on one side of the pressure chamber and a U vent (to collect condensate) on the other. The trick would be to keep the reservoir full of water and at the same level as the U seal. This way the water level would be in equilibrium (something about fluid hydraulics and Pascal's law) and as the heater boiled off water you would be able to ensure that the heater was still covered.

Other people might have better ideas, but this will reduce the impending explosion probability.

 

[Hamaki]

Mechanical engineer here:

To mathematically/thermodynamically tell you why this is a bad idea we can assume the water inside the pressure vessel is ideal. And while it isn't exactly the right law to use, it will suffice to use the ideal gas law== PV=RT, with R being the universal gas constant.. essentially you can change any two of the three variables and it will fix the third.

In this case you have a fixed volume with a variable temperature, which will fix your pressure, BUT the temperature is changing so your pressure will change proportionally. This is where you may reach your pressure threshold and cause an explosion.

My solution would be to install a reservoir vented on one side of the pressure chamber and a U vent (to collect condensate) on the other. The trick would be to keep the reservoir full of water and at the same level as the U seal. This way the water level would be in equilibrium (something about fluid hydraulics and Pascal's law) and as the heater boiled off water you would be able to ensure that the heater was still covered.

Other people might have better ideas, but this will reduce the impending explosion probability.

As mentioned earlier, this approach would be safe but with water as the heat transfer fluid in the inner chamber temps would reach no more than 212F at one atmosphere. This does not allow much delta T to affect wort temp. For this concept to work safely there would need to be a heat transfer medium with a much higher boiling point at one atmosphere or a safe method of holding a higher pressure on the water to raise boiling temp appreciably. If a pressure release & water are used I would assume that there is some risk of boiling off enough water that part of the element would be exposed. Although I've heard some claims about ULWD elements being able to withstand dry firing, I'm not sure how long or how frequently this can be done without damaging or destroying the element. Though a method might be devised to maintain a high liquid volume in a pressurized inner chamber to keep the element immersed I suspect it would be beyond the means or ambition of most home brewers.

 

[Facinerous]

Thanks for all the responses everyone. You have all help me find a solution to my stupidity. With respect to ambition I would like to toot my own horn by saying there is no lack of. Ajwillys is right in that this is technically a HERMS, not RIMS, concept.

I have been delving into the wonderful world of thermodynamics, and all of its awesome confusing ways. Its actually not to bad, but including time in the equation has got me stumped at the moment. This is mainly to determine temperature change of wort entering the the heat exchanger and heat of wort exiting the heat exchanger with known temperatures.

I agree that using an open vessel would be the safest means of utilizing what I have created. I need to prove that this would be adequate though before I commit to a final design. The temperature difference may not be enough to raise the wort temperature any appreciable amount in order to provide the ability to use a step mash process. I believe that it would be adequate in maintaining temperature though.

This is all with regard to post #18 in this thread in which I explain a design concept to alleviate my original design flaws.

I have a tertiary design worked out in my head which would allow for pressure to be developed within a closed heated system with the appropriate safety features incorporated. Before I decide on which system I ultimately use I need to rough out the math first though.

 

[uatuba]

Here's the thing...it actually IS a RIMS...you're just modifying your heating element to be slightly larger and probably less efficient. The medium between the element and the wort don't really matter--when we're talking about that low of a volume of medium, it's really doing nothing more than extending your heating element. If the medium can get as hot as the element, you're not protecting yourself against scorching any more than direct contact with the element would. If it can't, you're losing efficiency.

I don't want to say that this is a fools errand, but...

 

[Bobby_M]

There really is no hardline distinction between RIMS and HERMS. I think it's a goofy thing to try to define because it's all "heat exchange" and even what people call HERMS system are in fact recirculating infused mashed. What we are really talking about is an inline electric heating system vs. a water bath heat exchange system. I know for sure a bunch of crafty homebrewers can do a lot better naming job than RIMS and HERMS.

 

[Facinerous]

Ha ha. I guess I should make this a hybrid and run it on gas and electric. Couldn't be the first hybrid made out there for this application... Or maybe it would be.

 

[Facinerous]

Well. I finished all the attachments to the little beast. Filled with water and am running preliminary testing. All in all its pretty funny but I like it.

 

[Facinerous]

Well... Testing is complete.

Ran test of this system with no grains, just water. Will maintain mash temperature no problem. Has step mash capability as it will raise temperature within the average listed time. About 15 degrees F in about 15 min. I check the amperage is for the element. Its about 10 amps. So my 1500 watt element is really only about 1200. I may ultimately choose to use a higher wattage element with this system. I have not decided on that yet.

Upon going through this testing I learned something extra as well. I had been looking around everywhere for calculating the heat dissipation I should expect from what I had created. After running the numbers a few different ways I never got what I would have expected as an appropriate answer, so I passed it off as I was incapable of fully understanding the dynamics of what was going on.

After running the test today, I realized that my numbers were actually correct. The heat dissipation of the wort in the outer shell from the inner tube would not have allowed for the tube to become a bomb. The heating element would barely be able to keep up with the dissipation. I could have expected about 25 psi to have developed within the tube, and having a 50 psi Pressure release valve for safety would have sufficed. Although this is what I have found I am only about 99% certain that I am correct in my math.

I still can not recommend my original design to anyone, but the final design works well for my application and reasons for having an isolated heating loop from the wort.

 

[horseinmay]

Interesting what this thing has turned into. It's a HERMS with the heat exchanger on the outside of the reservoir.

 

[sablesurfer]

Ok, missed something, the red cannister is for? Is that the blow off area incase pressure is too high?

 

[Facinerous]

The red canister is just a water reservoir. Its function is to maintain the water level over the heating element, and to circulate the boiling water. It works like a coffee maker.

 

[Stealthcruiser]

The red canister is just a water reservoir. Its function is to maintain the water level over the heating element, and to circulate the boiling water. It works like a coffee maker.

Sounds a might familiar...........

 

[TallDan]

After running the test today, I realized that my numbers were actually correct. The heat dissipation of the wort in the outer shell from the inner tube would not have allowed for the tube to become a bomb. The heating element would barely be able to keep up with the dissipation. I could have expected about 25 psi to have developed within the tube, and having a 50 psi Pressure release valve for safety would have sufficed. Although this is what I have found I am only about 99% certain that I am correct in my math.

That is assuming the wort was still flowing through the tube. If the flow of wort stopped (stuck mash, failed pump, forgot to open the valve) the temperature and pressure would quickly climb and potentially become dangerous.

So, are the tubes going from the fire extinguisher body just open so that if water boils off, the steam with to through the top tube and water will backfill from the bottom?

 

[Facinerous]

Yep. That's it TallDan. The volume of water in the reservoir tank just puts water pressure (the weight of water) on the bottom tube to the heat exchanger. So as the element boils any water in the inner tube of the heat exchanger it is pushed out the top and back into the reservoir. And of course I have to add the reservoir is not sealed

Also your right Dan in that there are plenty of ways my original design could have become over pressurized due to stuck mash, stopped pump, and the like. Ultimately this is much safer. There is actually more I could do with this little project but I think for now I'll just have to leave it as it is.

All I need to do is add the thermocouple and final PID I intend to use into the wort loop and it will be finalized.

I showed one of the guys I work with who also brews my little creation. His response was "What the hell is that?" I thought it was perfect, that exactly the response I was looking for.

@Stealthcruiser : It was kind of funny because I had been running ideas through my head all day when I came up with this little concept. So when I got home I did laugh at the post you put up because it was basically validating my idea to go in the direction I did. Thanks for the input.

To everyone thank you for your input as well. Thanks for helping this thread become productive.

Last note. From what I have completed I would call that phase one. If that phase were not to perform up to what I wanted I did have a phase two in store which would have just added onto what you see in the last picture I posted. I may still act on phase two, but that will be after a few test batches of brew to see how this thing does. I can't help it. I just like geeking out on projects.