saturated steam
saturated steam
(OP)
Dear ALL:
I have saturated steam line using in distillation unit with pressure 5.3 so the expected temperature is about 160 C , but actually the temperature is 140 C
what is the possibles causes for this case? can any body help me ???
I have saturated steam line using in distillation unit with pressure 5.3 so the expected temperature is about 160 C , but actually the temperature is 140 C
what is the possibles causes for this case? can any body help me ???





RE: saturated steam
If you are measuring both parameters at the same point then there are 3 possibilities:
1. Your pressure gauge is faulty
2. Your temperature gauge is faulty
3. Your fluid is hot water
Katmar Software - AioFlo Pipe Hydraulics
http://katmarsoftware.com
"An undefined problem has an infinite number of solutions"
RE: saturated steam
I've measured at the same point
your assumption is correct it is bar gauge.
I've calibrated the pressure and temperature gauges and its working correct.
for more explanation:
the line is filled with purified water and its heated by industrial steam (heat exchanger)
the industrial steam temperature is 175 C and about 8 bar
it is possible that the line is pressurized and thus the Boiling point increase , so it still hot water ???
RE: saturated steam
RE: saturated steam
Katmar Software - AioFlo Pipe Hydraulics
http://katmarsoftware.com
"An undefined problem has an infinite number of solutions"
RE: saturated steam
I check that there is a steam raised from the output of the line
I still searching for the exact reason !!!!
RE: saturated steam
What you have described is impossible, so you need to give a more accurate and complete description. One of the joys of science is that Nature's laws are always obeyed. Unlike human laws.
Katmar Software - AioFlo Pipe Hydraulics
http://katmarsoftware.com
"An undefined problem has an infinite number of solutions"
RE: saturated steam
Please explain how you determined that there is steam under pressure?.
If you did this properly you would have drilled a probe hole for the pressure and temperature gauges measured near the pipe center you would have NO way of visually knowing whether there was steam inside the pipe.
Obviously,if you see steam escaping it is under ambient conditions and it is flash over.
Bottom line, if you accurately measured the temperature and pressure (you posted) inside a closed pipe, there is NO doubt that you have pure water, no steam.
RE: saturated steam
RE: saturated steam
RE: saturated steam
you will note that the position of temp and pressure gauges
not the inlet purified water (PW) temperature (70 C)
RE: saturated steam
RE: saturated steam
I cannot understand whether this situation has been noticed before or weather this is the first time you have those readings for temperature and pressure gauges.
What you can be sure of, as stated by others above, with those readings you have only hot water.
RE: saturated steam
RE: saturated steam
If only hot water enters this tank (as we all think) you should be getting very little steam output.
And why is this suddenly a problem? Or is this a startup facility
RE: saturated steam
RE: saturated steam
RE: saturated steam
RE: saturated steam
RE: saturated steam
rmw
RE: saturated steam
each vessel have demister at upper portion ,
zekeman : our major problem that the output steam from the last vessel is too low as you thought,the problem encountered when increase the demand on the output , and the machine designed to produce more output
note that the industrial steam enter only the first vessel and then return to back line
RE: saturated steam
rmw
RE: saturated steam
RE: saturated steam
Or... the 'purified' water is loaded with air or some other dissolved gas so that as was stated much earlier in this thread, there is a partial pressure relationship going on between the steam vapor present and the noncondensable gasses present.
rmw
RE: saturated steam
This has been going on too long
By now you (we) should have figured out your problem.
The speculation on entrained gases vs pure hot water could be resolved as follows
You need to find out what is entering tank 1 and then do an energy balance to help resolve the issue.I propose the following crucial steps to get started:
1 get the temp, pressure and flow rate of the steam entering tank 1
2 get the temperature, pressure and flow rate of the water entering tank1
3 do a heat balance as follows
[(Uhw*w' +Usteam*w"]/(w'+w")= k1*Uwater2+k2*Usteam2-thermal heat transfer losses per lb of fluid per unit time
Uhw=internal energy of water (70 deg)
Usteam= internal energy high pressure steam
w' flow rate of incoming water
w" flow rate of incoming steam
k1 fraction of incoming fluids that is water
k2 fraction that is steam in tank
U water2 internal energy of assumed saturated water
Usteam2
This left hand side gives the average internal energy of the mixture in 2.
Now based on your measurements you should be able to get k1 and k2 the fractions of that energy that might be allocated ( first assume adiabatic
ignoring thermal losses from the tank)
Post you results and we can further assist.