Scott Weinberg

Robert Ray,

it has been about a week, but don't know if you started any part of the experiment, if so, any hot sand showing up? Enough to heat a room?

Scott

Von Xiong wrote:Scott I don’t even know what all that means!! Why do I need to know fire brick size? I’m gonna do a little research what you given me though, best if I can talk to someone. I will have a 110 feet of bench and in the ground. For the bell I want to make a chamber for ceramic. What’s left right rear exit? My main concern is how do I insulate the pipe under my ground in the greenhouse. Like what materials should I use and how much. Thanks Scott for your time.

Scott Weinberg wrote:

Von Xiong wrote:Hey all! In the next week or so I need to build a 8 inch batch box and I need the design template. Where can I get it?

Von, Looks like you started two different threads searching for the "answers", with Dragon Tech already giving you the dimension basic page.  Depending on the details, you would have much to do, before NEXT WEEK, depending on what you have available.  Along this line would be some questions to be answered only by you.

- fire brick size
- bell brick size, single layer bell or double, with bench or not
- extended batch chamber or not
-  standard batch with riser, sidewinder, or perhaps the latest, the shorty
- right, left or rear exit flue
-raised burning unit or base level
-size of glass on the door or no glass at all

This is not to discourage you, but rather helping you to formulate your game plan as these stoves are rather perminate in nature, and certainly can't be moved once done.  Best of success.

Von, I will touch just a few of the basic's on the "need to know and reasons for them"

1) You stated you wanted to know the layout of a 8" system, But you did not say where you intend to have your flue? So I am trying to figure out, how you interput any layout suggestions to match what you want to do? That was why I said that.  or rather bluntly, have you ever heard of anyone that has done what you intend to do?

2) If you don't know any of the answers, to the various options you can have for a 8" unit, I refer back to number 1, everything is so important, and depending on how you intend to experiment, None are super easy to simply change to something else, if things don't work for you. again, not to discourage you, but have you seen this work? ( what you intend to do ) and to jump in "next week "

3) 110 foot of bench?  Do you understand the basic's of ISA (internal surface area)  and how it relates to the overall operation of the unit? Lets say you really do attempt to have at minimum this 110 of bench, Do you understand what happens to the flow of the hot gases, when cooled beyond 140 degree's?

4) you mention you would like to talk to someone,  if you were to do that, and everyone was honest about it, I am thinking 1 to 3 items would all need to be discussed, thus the reason for my statements in the first place    Just trying to be helpful, in saying there is a lot more to what you want to do than simply understanding how to insulate what I presume is below the 110 foot bench.

5) lastly you mention, a chamber in the bell for ceramic?  Again, I mention, the need to understand  how the forces of hot gases make the system work, ( extraction of BTU's)  while a 8" system can be mighty powerful, if you defy phyics, you will likely come out on the short end.

So where would I start?    The very first thing I would do, is find someone that has even remotely done what you intend to do? There is no shame in replicating  a known system that works. VS having a system that simply will not function.   I hope someone steps forward that has such.

Best of success.

Von Xiong wrote:Hey all! In the next week or so I need to build a 8 inch batch box and I need the design template. Where can I get it?

Von, Looks like you started two different threads searching for the "answers", with Dragon Tech already giving you the dimension basic page.  Depending on the details, you would have much to do, before NEXT WEEK, depending on what you have available.  Along this line would be some questions to be answered only by you.

- fire brick size
- bell brick size, single layer bell or double, with bench or not
- extended batch chamber or not
-  standard batch with riser, sidewinder, or perhaps the latest, the shorty
- right, left or rear exit flue
-raised burning unit or base level
-size of glass on the door or no glass at all

This is not to discourage you, but rather helping you to formulate your game plan as these stoves are rather perminate in nature, and certainly can't be moved once done.  Best of success.

Robert Ray wrote:I don't have a RMH, but I do want to try a sand battery heater in the green house.
My test will be creating a sand battery 2ft x 2ft x 12 ft corrugated sides, to simulate the mass of a RMH Two courses of bricks at the base, the remainder will be filled with sand.
I picked up the bed materials today from Home Depot. Spent some time with Jeff Besos ordering heating elements from Amazon today.
My experiment will be placing the different elements within the central 4 feet of the bed.
The heating elements I ordered consist of a broiler element, a water heating element, an industrial immersion heater, a clothes dryer heating element, an eight inch stove top element, 6 PTC elements. So about 150.00 dollars worth of different heat sources that will be placed within that central 4 feet of the 12 ft bed. .

That is fantastic and sounds like you will have a excellent systematic way of testing the results.  I am sure there are many that will await your results. Please do keep us informed.  Best of success!

I know it has only been a few days, but did anyone decided to heat up their sandbank with excess wattage from there solar panels?

Is your typical panel around 350 Watt with a  typical excess planned for about 3 hours per day?   or about 1050 watts per panel if you have that much excess.

So this is about 3500 btu's gained per panel if you have that much excess or about 3/4 of a pound of wood for heat production per panel

 My engergy coop does not allow for us to install EXCESS production, unless we are off grid.   So we have NO excess that could be harvested per say.   But it sounded like a lot of you, had excess wattage, and figured it would be easyily accebbible,   So I was wondering how the sand was warming, and how warm the sand was getting.  

Would like to see the results.

I am hoping one of the many that support this idea can give the rest of us a report.

Simply take a steel container, a 20-30 gal oil drum seems like it will work for this test.  if your in north east Iowa, I would give you a barrel or three.

Please pick out a location for your resistance wires/rod/element, what ever you want to call it. And please do tell where you put them  in your mass,  And then fill the barrel up with sand.

At this point, plug into your solar panel and let it start charging, (passing voltage to the element)  or if you want, you buy a 110 volt water heating resistant element as many of you stated these are only 10-15 dollars.  Plug it in and let it rip. Make sure you record temp of sand at bottom, middle and top,  And if you like, let us know of which method you used. What size you used and what the dry sand weighs, that way we can easily figure out how many BTUs your bank is storing

Let us know the results after one day, then two days and so on.  Make it scientific, your test could help create world peace.. So this will require nice dry sand as wet sand might be not safe and possibly a bit variable due to temp variations,  sand grade or size would also be nice, so others can duplicate when it works well for you.

And at the end of next week, you should be able to post the results.  I would think sand weight, sand height, and volume will also help.  Keeping it simple as stated on this forume,   would be is very important. No need for switchs, just let the mass storage begin and then report NOT what is thought should happen  but what it really did happen.  

We will wait for the results. and please let us know.

Benjamin Dinkel wrote:I do think Scott has a point here.
Sand is cheap, available and easy to work with.
But it’s also somewhat of an insulator. So apart from the heat capacity (1200 kJ/(m3*K) in sand vs 4200 kJ/(m3*K) in water)the question of how to heat it up is an important one.
I don’t know how the fins took care of that. Maybe pressing air through the sand?
There’s a reason a lot of heat storage happens with water. Not the best conduction either, but when you heat some it rises so your heater can continue heating cooler water. And it has a big capacity.
Is water an option for your case?

Or is your question rather whether anyone ever installed an electric heat source in their RMH mass?

Thanks Benjamin, if I may, I will explain a bit more, where I feel projects go from basics to complex, and maybe I am missing something, but in general, this is often how it goes.

if we consider our base heating system being used  in of the latest stove designs, which heats our mass in as effecient method as we possibly can, and we have proven all over the world that we can do this with NO mechanical means.

From this, we as rocket designers-users-even dreamers, start looking at additional storage methods, thus the name of this thread. Very quickly we note IT CAN BE DONE, but just as quickly find in most cases that it involves, a vast addition of mechanical means.  I bring this up, for one reason only, that being, I was not trying to say it can't be done, but rather if it is attempted, beaware that it can easily approach a level of no return on investment.

All great ideas start somewhere,  I just wish some of these ideas go down the practical path first, then get cleaned up,  Rather than proposing a dream, and spending years to convince others that it just maybe, quite possibly, with greatest of hopes, can work.

Sorta like spending $10K to save $1K, we often see in many simple ideas that have grown into complex ones. Another proof of this is the very often "showed on the internet" technolgies that promise great things, just as soon as they get
1) funding
2) figure out a way to make it work for the masses,
3) more funding,
4) and get technology to let them do what they proposed.  
     This of course is not true in all cases, but is generally par for the course.

Best of success!

Dry sand has proven to be a pretty good insulator, and pretty poor at heat storage,(getting it uniformally heated up) vs brick/stone and other solid material.  Although It can be transportaed and placed fairly easily. that does not make it that versistal for heat storage.  And of wet sand works great up to the boiling point of the "wetness" But that is a whole different can of worms.

Pebble banks, for much of the same reasons. Both have similar claim in that they are easy to build with.