Verfahren zur Bestimmung der in einer Zweiphasenströmung mit gasförmigem Trägermedium enthaltenen Menge festen und/oder flüssigen Materials

摘要

The invention relates to a method for determining the quantity of solid and/or liquid material contained in a two-phase current with a gaseous carrier medium. A preferred area of application of the invention is the determination of the quantity of coal dust pneumatically transported in the burner pipes of a coal-burning power plant and the detection of streaks. According to the invention, whether a two-phase current is loaded with solid and/or liquid particles is determined on the basis of the frequency shift of an almost linear area of the damping curve below the limit frequency determining the spread of electromagnetic waves. This linear area, which is similar to a step function, is largely stable in terms of its shape but increasingly shifts towards lower frequencies as the particle load increases. According to the invention this frequency shift is detected by means of electric alternating fields and the load calculated therefrom. Any streaks present can be detected by determining the load in different azimuthal directions of the stimulated electric alternating field.