- #1
Dennis C
- 44
- 2
Upstream Conditions: Saturated steam, 230 PSI, 399 degree F.
Downstream conditions: 170 PSI
Assume 98% quality steam
We throttle steam to our distribution system for use by hospitals for sterilization, heating and autoclaves.
I have a theory of what is happening after throttling and would like to know if this is correct.
After flow through the pressure reducing valve, any moisture in the steam will "flash" because its temperature is greater than its corresponding saturation temperature at that reduced pressure (170 PSI). Then it is possible that the temperature drop may stop before getting to saturation of 170 psi because all of the moisture has flashed to steam. (assume mass flow rates of 100 mlb/hr)
A lot of people (coworkers) are under the assumption that the steam temperature after the valve will be saturation temp of 170 PSI because it is at 170 PSI, but I disagree for the previous stated reason. I ask them where did the energy go besides losses due to noise and velocity changes, they don't have much of an answer. that's why I am here.
I understand we can measure the temp diff across the valve, but I would like to understand why.
Thank you
Dennis
Downstream conditions: 170 PSI
Assume 98% quality steam
We throttle steam to our distribution system for use by hospitals for sterilization, heating and autoclaves.
I have a theory of what is happening after throttling and would like to know if this is correct.
After flow through the pressure reducing valve, any moisture in the steam will "flash" because its temperature is greater than its corresponding saturation temperature at that reduced pressure (170 PSI). Then it is possible that the temperature drop may stop before getting to saturation of 170 psi because all of the moisture has flashed to steam. (assume mass flow rates of 100 mlb/hr)
A lot of people (coworkers) are under the assumption that the steam temperature after the valve will be saturation temp of 170 PSI because it is at 170 PSI, but I disagree for the previous stated reason. I ask them where did the energy go besides losses due to noise and velocity changes, they don't have much of an answer. that's why I am here.
I understand we can measure the temp diff across the valve, but I would like to understand why.
Thank you
Dennis