http://thorconpower.com/wp-content/uploads/2019/03/ColdWallLoopAnnotated2-1024x768.jpg http://thorconpower.com/wp-content/uploads/2019/03/ColdWallL... This one

http://thorconpower.com/wp-content/uploads/2019/03/ColdWallLoopAnnotated2-1024x768.jpg http://thorconpower.com/wp-content/uploads/2019/03/ColdWallL... This one is just a bunch of separate tanks spaced as far away from each other as possible. I've also seen a "Bed of nails" design where the liquid salt would flow over a bunch of moderating spikes, seep down between them and freeze.