Thermosyphon loop cooler.
This apparatus is used in industrial applications for advective transport of heat from source to sink with a circulating liquid without employing a mechanical pump. Heat is added to the left leg and removed from the right leg. The density in the hot leg (ρH) is lower than in the cold leg (ρC), so the liquid level in the hot leg (ZH) must be higher than in the cold leg (ZC) to maintain the force balance between the two legs. The resulting difference in level (Zdif) causes the flow to circulate. The apparatus is self-regulating because an increase in heat input increases the temperature of the hot liquid, which decreases its density, increases the difference in level between the two legs, increases the flow rate, and thus increases the rate of heat removal. The thermosyphon loop cooler behaves in basically the same way as the AMOC.