Thickness of ice

[deangardner]

If I had a cold trap cylinder that had a internal surface area of 1 meter squared, the trap material was stainless steel that was 10mm thick. The chiller was -60 degrees c on the outside of the trap. For argument sake, the material entering the trap is water vapor. How do I calculate the thickness of solid that would form? The thickness would be from -60 (or whatever the conductivity of stainless steel at 10mm is) to the thickness where the ice changes state? Static, regardless of time?

 

[zdas04]

At that temperature, the thickness of the ice is a function of the mass flow rate of water vapor (look at a psychometric chart). Eventually the vessel will be full of ice.

David Simpson, PE
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. —Galileo Galilei, Italian Physicist

 

[racookpe1978]

What is the geometry of the cold trap?

No sketch or no geometry, AND no flow rates of the incoming vapor, AND no relative humidity or saturated vapor mix or cteam/condensate conditions = no solution to this (textbook ?) problem.

 

[bimr]

If you are manually changing the trap when it ices, the thickness will be whatever you desire.

You can assume all of the water vapor is deposited as ice. The thickness of the ice can be determined by the density of ice. The density of ice is about 90 percent that of water, but that can vary because ice may contain air.

 

[zdas04]

91.7% at the freezing temperature at atmospheric pressure. At lower temps it is higher (-180C is 93.4%). The volume of liquid water only increases about 4% on freezing, so I thought the density should go down about 4% so I looked it up. A lot of different values on the Interwebz, I found four with the same value from places with .edu in their URL. The .com answers are all over the map (depending on the author's agenda apparently).

David Simpson, PE
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. —Galileo Galilei, Italian Physicist

 

[chicopee]

I have issues with the OP which are: 1) the initial conditions such as temperature and pressure of the water vapor are not provided because if provided then we can determine if we are in the sublimation zone or not 2) Is the initial temperature of the cylinder at the same temperature as the chiller 3) how big is the trap because the heat transfer between the cylinder and the vapor may or may not include convection 4)is the cold trap cylinder an enclosed system in which the water vapor is depleted by changing state to ice. Without such information, we can be all over the place in trying to formulate an equation.