Hete bron

thermo1945

Is er ergens in de diepzee een plek bekend waar het water kookt ondanks de hoge druk?

Klintersaas

Je vraag doet me denken aan de zgn. black smokers op de oceaanbodem. Het daarbij betrokken water wordt er verhit tot wel 400°C, zonder te koken. Dit verschijnsel staat bekend als kookvertraging.

Jan van de Velde

Voordat snellezers over de relevante info heenlezen:

http://en.wikipedia.org/wiki/Superheated_water

In het Engels lijken die termen nogal op elkaar, verhoging van kookpunt onder hogere druk, of het niet optreden van kookverschijnselen ondanks het overschrijden van het kookpunt bij de heersende druk (door gebrek aan kookkernen)

thermo1945

Is er ergens in de diepzee een plek bekend waar het water kookt ondanks de hoge druk?

Dank heren maar het is nog geen bevestiging. Misschien onderin de black smokers nabij vulkanische activiteit.

Klintersaas

Dank heren maar het is nog geen bevestiging. Misschien onderin de black smokers nabij vulkanische activiteit.

Ik vrees dat er inderdaad geen enkele plaats op de zeebodem is waar water in gasvormige toestand voorkomt:

Deep sea hydrothermal systems are composed of 3 basic zones: the recharge zone, reaction zone, and upwelling zone. The recharge zone, the surface/near-surface area in which water enters the ocean floor, can extend for miles. This zone is nearly the sole source of water for the hydrothermal system. At the vents, there is invariably some magmatic water exiting, but it is an extremely small amount in proportion to the sea water traveling through. The reaction zone is a relatively small (compared to other zones) region within the earth, near the magma chamber, in which the water is heated to the point at which it begins to rise toward the surface. This then turns into the upwelling zone, where water is carried upward by its lower density and the push of water below it. The upwelling zone ends at the surface where the water is expelled from vents of various shapes and sizes. Unlike subaerial hydrothermal fields, water cannot rise diffusely through the surface. Moreover, the fluids will not rise in vaporous form as occurs above sea level. Each of these peculiarities has a specific reason, however.

Water does not rise diffusely through the surface; neither does it enter diffusely through the recharge zone. The reason for this is the high density of the basalt under which the system is located. Basalt (with the exception of flow tops) has almost no pore spaces to store water, and those few that exist are very poorly connected. Basalt, however, is extremely brittle meaning that there are numerous cracks through which water can travel very quickly. As the heated water from the reaction zone rises upward, water from elsewhere is drawn into the empty cracks and so water is constantly being drawn in to the cracks of the recharge zone. Thus a cycle is created, fueled purely by the heat of the magma chamber and transported along the fissure system of the basalt. Neither do we find water vapor at deep sea hydrothermal fields, due to the pressure at these depths. Here water remains a liquid at temperatures of up to 400 degrees C, which can be reached at these vents.

Bron: http://mivo-sys.tripod.com/hydro.html

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