What is barometric leg?
A barometric leg is basically a condensate drain. In a vacuum system that is used to condense steam and condensable vapors through heat exchangers or condensers, the condensate is normally dropped into a receiver tank that is often vented to atmosphere or a low-pressure vent system.
What does barometric height mean?
n. 1 an instrument for measuring atmospheric pressure, usually to determine altitude or weather changes. 2 anything that shows change or impending change.
How do you use the barometric formula?
M = kg/mol. Note that the model calculation assumes a uniform temperature, and is therefore not a realistic model of the atmosphere. The temperature tends to decrease with height, so the model calculation will overestimate the pressure at a given height.
How do you measure the height of a barometric leg?
As an example, let’s assume the maximum barometric pressure at a plant is 30″ HgA and that the condenser is operating at 4″ HgA, then the minimum required height of the barometric leg is a liquid column equating to 26″ Hg. As 1″ of Hg equals 1.133 feet of water, a minimum barometric leg of 29.5 feet is required.
How do you calculate barometric legs?
Just locate the Condenser a suitable distance above the Receiver, and the water will flow downhill against the pressure difference. The calculation of what constitutes a “suitable distance” is what you call “calculate barometric leg”, since the piping between the Condenser and the Receiver is called the barometric leg.
What is the purpose of the barometric height formula?
The barometric formula, sometimes called the exponential atmosphere or isothermal atmosphere, is a formula used to model how the pressure (or density) of the air changes with altitude. The pressure drops approximately by 11.3 pascals per meter in first 1000 meters above sea level.
How do you derive the barometer equation?
Derivation of the barometric formula at constant temperature 3 is used again for the pressure and mass density at sea level: M/RT = ρ0/p0. The value of scale height H is between 4 and 8 km depending on the temperature.