i had this idea a few years ago. MrJohn613 Rocket mass water heater concept

i recently saw a thread that sparked my memory.  im an "idea guy" , i always have at least a dozen ideas ready but never the time and resources to accomplish them all by myself.  here's the idea i had which i recently tried to explain to a member but i think it might be best explained in this concept diagram i made comparing a residential propane hot water tank to an idea of something similar, without the propane.  these tanks have a central heat riser built in, and a pressure relief valve built in.