Mattia, you can also measure the steam quality by measuring the speed of sound in steam. This is correlated with amount of liquid water droplets in steam suspension. Therefore you do not need to condense steam in order to find it's quality.
In close to room pressure it is really not necessary to condense the steam, but it is enough to measure steam quality and separate hot water and steam with water trap. This gives the mass flow of steam and thus we can calculate the total enthalpy from humidity sensor readings. Usually water boilers are designed thus that there is build in water trap so that only steam escapes. With tube boiler this is however the case due to percolator effect. Of course it would be easier and more reliable to condense the steam by sparging it into the water bucket and measure the change of water temperature. Then we would not need to worry about the amount of overflown water. —Jouni On Sep 22, 2011 6:21 PM, "Mattia Rizzi" <[email protected]> wrote: > It’s the manufacter that say the readings are useless, not me. > If you don’t trust the manufacter, then provide a single reference from the literature that say that it’s possibile to measure the entalphy/steam quality/ecc from a RH reading. I challenge you. Nobody do it. ISO standard is to condensate the steam. > From: Jouni Valkonen > Sent: Thursday, September 22, 2011 4:45 PM > To: [email protected] > Subject: Re: [Vo]:About measurement of steam with Galantini probe > > Peter, in order to measure the enthalpy you need to know the mass flow of steam. This is not known therefore humidity sensor gives only the amount of liquid water in suspension with steam. That was measured 1.2% and thus steam quality was 98.8%. > > Problem is that critics such as Mattia Rizzi and Krivit has wrong definition for steam quality. Measuring steam quality is irrelevant because it is always 99-98%. Instead what would have been necessary to measure, was the mass flow of steam. This was not measured, therefore steam quality reading is useless. It tells only that 98.8% of steam mass flow was vapor and 1.2% was liquid water droplets in suspension. But indeed this does not tell us how much liquid water was overflown that was not in suspension with water vapor. > > I wonder how long people will repeat this Krivit's silly misconception! > > —Jouni > > On Sep 22, 2011 5:25 PM, <[email protected]> wrote: >> >> >> >> ----- Original Nachricht ---- >> Von: Jed Rothwell <[email protected]> >> An: [email protected] >> Datum: 22.09.2011 15:53 >> Betreff: Re: Aw: [Vo]:About measurement of steam with Galantini probe >> >>> [email protected] wrote: >>> >>> > Now what happens, when an inventor without deep knowledge and experience >>> constructs a steam device, makes it unaccessible and then lets unexperienced >>> scientist measure the steam? >>> > Most scientists expect that devices that they use are properly constructed >>> and work as designed because they know nothing else. >>> >>> Some questions for you and other self-appointed experts here: >>> >>> How much deep knowledge and experience do you have? How many steam >>> devices have you constructed? Have you done calorimetry on this scale? >>> What do you know about Galantini's background and his previous work? >>> >>> You are presumptuous. >>> >> >> I do repair professional devices and had contact with many professors and doctors in chemical labors using our products. >> I have experiences with chromatography devices (with the electronic sensors,and computers, not with the chemistry), and with microparticel measurement devices and with continuous flow devices. >> All these dont only need calibration, fresh calibration is sometimes needed before each measurement. >> I have no experience with steam measurements, but was reading a lot in the last time and I learned that this are heavily nonlinear problems with many variable known and unknown parameters and it is too easy to make mistakes and too easy to fool others with such measurements. >> >> >>
