Matt I like your idea. Run a large gasifier to fill a gasometer, with nothing being a mere “byproduct”.
How exactly will the gasifier run the gas to the gasometer for storage? A push blower at the air inlet or an inline blower pulling and then pushing? It would need enough power to displace the water.
Or are you going to lift the gasometer with a crane and use the vacuum of the water resisting the bell lifting to provide suction?
Bob suggested using the Amtek blower and at first I didnt think it would work. Low and behold they use them for lifting huge boats!! Yeah those blowers are more than adequate to lift the gasometer drums. This will be fully automated and the gasifier will have self ignition process to recharge each gasometer on demand.
The main difference I see in the absorbtion vs compressor refrigerators is the speed that they cool. It is sort of like the race between the rabbit and the turtle. It takes a long time to cool an absorbtion fridge vs a compressor fridge but once it is cool it takes very little to keep it that way.
No problem Matt, Anthony confirmed what I wanted to know. Mainly, a cheap way to recharge a suspect automotive AC system. Jacob confirmed propane use as well… don’t need a black light or special dye…just recharge with propane, and spray dish soap on the engine…to find the leaks.
You have a Dometic thermostatically operated frig right? It has no pilot light, just fires up when the frig calls for cold? Those are way more efficient than solar powered compressor fridges. Then add homemade gas… sheesh 
.
I did it with a milking vacuum pump
kicking a dead horse here…
One of the many things that went wrong in the fluid bed and the Mk1 pressurized rig was I have no way to keep a handle on changing loads.
Its entirely possible with a fixed load gasifier that you could use the turbo and raise the pressure to operate at a fixed load.
Second problem was leaks…
I thought about this in the years since and A stupid idea hit me recently.
Since this is stationary just put everything into a big steel salvage drum and pressurize that.
Gas inter cooler included.
Now the pressure bearing parts are no longer the heat bearing parts as well.
And this might have a side effect of more effectively insulating and increasing internal temperatures… we are aware of the knock effective of this so I won’t go into detail.
SO…
Scaled correctly the system could once operational and up to pressure and temperature it should be able to power itself and make gas.
another turbo video ( uhg )…
But this one is making flammable gas that’s flaring after the exhaust.
Ya I was able to get gas out of the fluid bed and a lot more of it, but I could not deal with the ash slag issues and leaks caused overheating.
But look this guy has inadvertently made a crude analog of the fluid and he’s not making tar on the turbine side. ( he’s making glass, been there done that… )
How to achieve the right temperature…
Waste gate control is not enough…
I think you need to restrict the exhaust and the intake to make it all work.
I never tried this.
There is a point again when this thing just starts to make gas.
But at 9:21 it fries.
Look at the heat there is so much more potential here to make gas.
But all that heat is wasted not enough fuel inside to make use of whats going on.
Maybe the trick is the pulverized fuel from the fluid bed but somehow get it fed in after the intake on the pressurized side.
I still pick away at this in my mind because I know it can be made to work, I just don;t have deep enough pockets.
I bet 90% if not more of the process heat is lost because of a lack of insulation and too little space in the fuel hopper or maybe too much and it needs to be spoon fed pulverized fuel.
So much to learn and so little resources…
Ah yes I see a wood gas powered rocket in my future. lol
Its not a rocket or jet.
Its a self powered gasifier.
Part of the heat is harnessed to compress and run the machine.
I’m not crazy this can be made to work I just don’t have deep enough pockets or force of will…
Ill tell you something, else…
I had another better idea.
Put the fuel in a hopper and the build the gasifier around the fuel storage…
I need to draw this out and I will and post it…
Just cooking a pot of chicken soup watching the steam rise and it hit me…
Steam injection.
Bugger I solved it I think, to late I can’t spend any more money on parts.
Run with it Matt, if it works call it the Wallace will you Matt?
Who cares of you need to add more steam than normal it will drop out of suspension in the gasometer and your can decant it off the bottom…
I declare all my ideas here in the public domain free of ownership and royalty as of 19 May 2022
Wallace …
Wallace: I have the same thought… the pressure vessel needs to be (1) air tight, (2) strong enough to hold back the pressure, (3) tolerate heat and (4) insulate the heat for efficiency. You can actually solve those things separately.
An inner container can be soft at high temps but air tight. Put that in a bigger, stronger vessel tamping sand/perlite or other “hard” insulation into the gap. You could pressurize that inner gap as well to take force off the inner container and “hard” insulation but not critical. The outer shell will say cool enough and contain a rupture of the inner vessel if it occurs.
Pressure testing is safest if you fill the container to the top with water, then attach the pressurized gas to test for leaks and sufficient strength. Best practice is to use a good bit more pressure in the test than you expect to use in practice. Look for where the water comes out. That way you don’t have a large volume of high pressure gas in a suspect container, quite a dangerous situation in fact.
Hot steel is much weaker than room temp steel. I might use 5 to 10x working pressure in my test. But you do you.
More things need to be addressed.
The thermal runaway problem.
A more clever way to introduce more wood into the thing, and it has to be raw wood because even with wood and a certain moister content I think steam injection or gas re circulation are the only way to prevent meltdowns. ( by gas I mean not exhaust but literal sending gas back through a second time to reduce the incoming amount of oxygen with something that will not increase temperatures… I will add this will probably improve the chances of getting rid of any residual tar or CO2.
Proper heat regeneration to protect the turbo and improve efficiency is a must.
The only way it can work is at a constant load, pressure and fuel flow.
if one of these things change then the system will runaway, make tar or otherwise go haywire and I have consistently proved that you can;t build a small fluid bed gasifier this way.
Fluidbed is effectually a dead end at this scale.
A conventional hearth might work but all the tables are out the window under presure.
Now time to drop the matter because this is Matt’s thread about refridgeration.
(turbo included I destroyed a couple of used turbos and I gave up rather quickly )
Hi Bruce,
I have experience using propane in A/C systems. The R-12 systems used mineral oil for lubricant which is compatible with propane. Propane - or better yet - Butane works in them. Using propane for refrigerant is best done using a full supply tank as the butanes will vaporize first - leaving the lesser quality components in the tank. It is noticeable in the performance of a system if filled from a nearly empty supply tank. However - it is a fire risk and illegal to use in vehicles which were not originally equipped with propane. Mercedes had cars imported to the USA that had propane in them. There are special refrigerant type propanes available.
I’ve used propane in automotive systems to “test” them for function and leaks. Back about 10 years ago I replaced a compressor on my RV with a used one and filled with propane - not even using a vacuum source to evacuate air and moisture just to try it. The compressor was used and ended up having a leaking shaft seal. The seal leaked so badly that the system needed to be refilled within 3 hours. Had I been using R-12 I’d have spent a lot of money refilling it as I eventually emptied a 20lb tank of propane on that system. I came to realize that each time I filled it - the charge would last longer. Within a couple weeks a charge would last weeks. After a year - it didn’t need a recharge again in the next 5 years. It may still be charged today.
My LeSharo RV has a 3 way Dometic 2192 absorption refrigerator. This is a small refrigerator - only a bit over 2 cu/ft. I have used it on propane exclusively several times until it exhausted the propane supply to get an idea how long it would operate. The onboard propane tank is 6.5 gallons. Last year in August I left it on after returning from a weekend trip just to find out how long it would operate on propane. 4.5 weeks plus cooking several meals on the weekend. I had left 4 standard size water bottles in it - under the freezer. The temperature control was set cold enough that they froze solid. I also had a 2 liter bottle of soda inside. I opened the door 3 times to check for operation. This refrigerator has a co-axial type exhaust vent which can be touched with a bare hand to check if it is hot to know if the refrigerator is functioning. I’m attaching some files. One is of Dometic absorption refrigerator BTU and electric requirements followed by a file for the refrigerator I have.
Dometic-Refrigerator-Technical-Data-Chart.pdf (1.6 MB)
Dometic-Refrigerator-Installation-Instructions-RM2192-191442.001.pdf (2.2 MB)
I would like to bring up a recall and fire issue with some Norcold 1200 series fridges.
My Dad had one in his old RV and I replaced it with a DC fridge
It is unfortunate that he had to deal with a recall.
I have used 2 12v compressor refrigerators (one replaced a 110v only 2192 size Dometic) and 2 of the 3 way absorption units. And, one dorm size refrigerator/freezer that was supplied 110v from a 600 watt full sine wave inverter. I would not choose to have a refrigerator that relied solely on 12v. The current draw is so high that battery charge maintenance is a constant concern.
Rolling back the tape here Matt and I should have been more careful with my language about efficiency. The coefficent of performance for compression based systems is very high because a given amount of electrical or mechanical energy can deliver a multiple of that in terms of heat or cooling energy.
So compression systems have COPs greater than one, sometimes much greater. Pure heat driven systems never get that multiplier and so COP is less than one, often .5 or lower. That was my version of being right with a major but…. Here is the but…
If the electricity or motive power to drive the compression system comes from a heat engine then it is fair to compare the “fuel to cooling” efficiency of the compression system with the “fuel to cooling” efficiency of an adsorption system.
A char-gas fueled engine driving a compression cooling setup likely is less efficient than that same fuel driving an adsorption system. But in an RV with a high quality diesel engine? Maybe a belt driven compressor beats the built to price adsorption frig. In any case its close.
All that said… if a char gas fueled small spark engine is driving the compression… adsorption should be more efficient with the same load of fuel and certainly more efficient if adsorption uses waste heat, say from engine exhaust. You could charge batteries from a genset all while cooling a home on the “waste” exhaust of the engine. That’s a version of CHP you rarely hear about and one I am excited about.
efficiency of any technology is irrelevant in my case because Im using re claimed gas from the charcoaling process. This gas can not be used for engines but it can be scrubbed for low volume appliance like this fridge. A gas fridge regardless of efficiency will be more effient than converting the gas to engine shaft power. Any time you run these small engines you just lost 75% of the gas energy potential. Run the gas direct you converting all of it at the appliance minus its lower efficiency values. It will still beat the losses in the engine conversion.
This is very thought provoking. @abreaks prove cop for refrigeration is higher then one pls.
@Matt please reflect on your ideas and reroll your argument. You are picking the trash for pallets not pruning a forest. You can be cocky about efficiency until you have to roll down the road to get wood for your gas producer in your gas fired truck.
Its the same with me. Free oil to burn but I never could grow a soybean. If I had to buy diesel, efficiency would be really important.
What will matter is how much gas that gas-o-meter will hold, so you won’t have to refill it very often.
It will re fill automatically.
Oh boy - I’m not taking a view here at all.
A good mini split is 3 to 3.5 COP. Thats on electrical watts, shaft power will be somewhat less. Single stage adsorption is .5 to .7 COP that is easy heat watts vs hard electrical watts or engine hp. A 15% heat to electricity efficient genset driving a compressor is right in the middle off all that (15% x 3.5 COP ~ .5) It could come out ahead or behind.
A clever person could easily get ahead on the adsorption side of things. Maybe not with retail type RV frig but that is worth a test. And even if less efficient by watts it could be simpler and cheaper. Burning propane is way simpler than combusting it to turn a shaft.
But…. An engine could charge batteries with a genhead, turn a compressor and harvest exhaust heat for an adsorption system all together. For me that is the best version.
Whoops I didn’t mean for you to prove the comparison between absorption chemical refrigerators and vapor-compression cycles.
I was more interested in the proof of why a vapor compression cycle refrigerator has a COP of more than one. This is a very esoteric topic, that most people never get to the bottom of. It involves a lot of entropy. I was simply too tired and lazy to look it up and refresh my memory about it myself. I’m sorry.
The point I was trying to make with both of you, was that efficiency and placement really do matter. If you have a flame burning inside your camp it will heat up the entire camp. If you have a compressor running inside your Camp it will also heat up your entire camp. No matter the efficiency, the waste heat has to be released outside, or this gets ridiculous.