Drying time is not that important. I just need to have a basis for my design and some confidence that it will work. I don't want to be severely over or under-designing the system. So that's why I was looking for a calculation method to see if I was in the right ballpark.
Regarding...
I agree that airflow is important but I don't see how I can apply velocity over the chute into any determination of drying time. Assuming energy is conserved, then it doesn't matter how I get the 179,000 BTUs into the parachute, so the only way airflow is important is ensuring that I size my...
Ed, the reason I started this thread is because I don't know what formula I should be using. I could use the required heat of vaporization of water at my design temperature 120 F (43000 J/mol). If my 175 lb of water is 4410 mol, then it requires 189626894 J or 179,731 BTU per chute, so given the...
Yes, I used the ASHRAE Humidification DP/MCDB for the humidity ratio of the heated air and used an equation from the Engineering Toolbox which is something like: gh = Θ A (xs - x)
where
gh = amount of evaporated water per hour (kg/hr)
Θ = (25 + 19 v) = evaporation coefficient (kg/m2h)
v =...
My initial thought was also to dehumidify the air (either subcooling or desiccant wheel) then heat it but that is a big waste of money. I think littleinch is on point in the drying time is in the order of 12-48 hours, so the system doesn't need to be overkill, but I can't reliably say that it...
We are working with ParaDry on this project. They design the hoist systems. I spoke with their principal and he said he's seen lots of different system designs for the HVAC systems in drying towers. It doesn't sound like there is a standard design. He wasn't able to given me any names for...
Thanks Littleinch. Given your skydiving background, do you know grizzled old guys that have been doing this? I know some rigging and packing technicians that have been doing this for years but they aren't engineers, so they won't know nothing about enthalpy of vaporization. Plus they are our...
I know the mass of water. A company that manufactures hoists has submerged and weighed the wet/dry parachutes and given me this data.
These parachutes are very large so tumbling is not practical. The design of suspending individual parachutes from hooks on hoists by their canopies and allowing...
Hello,
I'm designing the HVAC system for a parachute drying tower. What equation can I use to estimate drying time? I know the amount of water in the parachute, the temperature and CFM across each parachute, and I can approximate the exposed surface area. I've looked at various equations for...
