Vapor Mass Flow Meter

Though not a networking topic, the development of “smart instruments” as a result of the associated digital connectivity was a contributing factor. While at the ISA Calgary Exhibition last week and during my day there had a chance to wander the floor for about an hour – between my time at the ISA Edmonton Section booth and when visiting the Honeywell booth once again saw their Versaflow meter not getting the attention it deserves.Vortex meters are often used for vapor flows. The formula m= (MW*P*V)/(RT) allows for the direct calculation of mass of a gas stream with constant composition from volume flow, pressure and temperature measurements.where:m = massMW = Molecular Weight of gasn= number of moles of gasP = PressureV= VolumeT = Temperaturer = “universal” gas constant, which is a function of the units for P, V, and T.Until recently calculating gas mass flow required multiple sensors however there are now two manufacturers (Krohne http://www.krohne.com/OPTISWIRL_4070C_Vortex_Durchflussmessgeraet_en.11250.0.html and Honeywell http://hpsweb.honeywell.com/Cultures/en-US/Products/Instrumentation/flow/VersaFlowVortex/default.htm ) who have integrated pressure and temperature compensated vortex meters so you can calculate mass flow for vapours/gases with a single meter. Several other manufacturers also have this calculation capability but require an external pressure signal to be connected to the vortex meter. The preferred way to measure steam flow is in kg/hr and fortunately, because the composition of steam does not change, the calculation of steam flow with a temperature and pressure compensated vortex flow meter is relatively straightforward.I cannot understand why these companies do not aggressively market this unique ability to measure vapor mass flow but hopefully this post at least raise the awareness for you should you have need to make this measurement.