Linde GmbH

Barometric scale factor The effective ambiant pressure (barometric reading) is used for a multitude of glass calculations. If this effective ambiant pressure is unknown, this formula assists to calculate the theoretical ambiant pressure.

Height above sea level m

Standard and operating conditions Often, volumina have to be converted into standard or operation conditions. Standard volumina are to be used to compare volumina with each other; operation volumina are to be used for dimensioning of machines, determination of speeds etc.

Standard cubic meter [Vo] Nm³ or operation cubic meter [V] Bm³ Effective or theoretical ambiant pressure [B] mbar Gas temperature [T] C° Gas pressure [p] mmWS

Oxygen supply In order to compare corrosive gas parts, they have to refer to a determined oxygen content. For all glass melting lines glass (except for purely electrically heated furnaces) applies a fixed O2 supply of 8 Vol.-%, whereas 11 Vol.-% are applicable regarding power plant technology,

Measured corrosive gas part (impurities) mg Measured oxygen content Vol-% Chosen resp. applicable oxygen content Vol-%

Leak air In any melting process, there is leak air entering the system by which energy is consumed unnecessarily. This volume of leak air (and thus the quality of the process) can be calculated on the basis of the varying oxygen concentrations that are measured within the melting aggregate.

Exhaust gas volume (waste) m³/h Oxygen content after entry of leak air Vol-% Oxygen content before entry of leak air or by combustion (l) Vol-%

Diagram humidity/HX By means of the relative air humidity which can for example be determined by a hygrometer, you can calculate the content of water vapour of air. This steam content, although having only minor influence on the characteristics of air, plays a mayor role, as this water has to be heated up and be evaporated with additional energy.

Theoretical or effective ambiant pressure mbar Air temperature C° Relative humidity %