Microwave measuring arrangement for determining the loading of a two-phase flow

Abstract

The invention relates to a microwave measuring arrangement for determining the loading of a two-phase flow with gaseous carrier medium in a tube or channel system (1) with small and extremely small solid and / or liquid particles. To that end, microwaves, preferably having frequencies between 0.95 and 1.05 times the frequency of the waveguide fundamental wave, are coupled into an electrically conductive section of the tube or channel system (1), the section being delimited by field rods (4, 4') and thereby acting as a resonator, and the shift in the resonant frequency of the resonator on accountof the loading of the carrier medium with solid and / or liquid particles is determined. In order to suppress interference resulting from microwaves which are reflected, diffracted and / or superimposedin the tube or channel system (1), two auxiliary field rods (6, 7 and 6', 7', respectively) assigned to each field rod (4, 4') are provided. The auxiliary field rods (6, 7 and 6', 7', respectively) are arranged at a small distance from the relevant field rod (4, 4') in comparison with the wavelength of the waveguide fundamental wave, and two auxiliary field rods (6, 7 and 6', 7', respectively) arearranged in each case at an angle alpha with respect to the field rod (4, 4') of alpha = + 45 degrees + / - 10 degrees and / or alpha = -45 degrees + / - 10 degrees and / or alpha = +135 degrees + / - 10 degrees and / or alpha = -135 degrees + / - 10 degrees, wherein the two auxiliary field rods (6, 7 and 6', 7', respectively) assigned to a field rod (4, 4') form an angle of 90 degrees + / - 20 degrees. The particular advantage of the solution according to the invention consists in a simple and space-saving construction that makes it possible to integrate the measuring arrangement into an existing tube or channel system even in the case of complicated space conditions.

Description

technical field [0001] The invention relates to a microwave measuring device for determining the loading of a two-phase flow of a gaseous carrier medium with small and very small solid and / or liquid particles in pipe or channel systems. A preferred field of application of the present invention is the determination of the loading of gas streams with solid particles in large volume pneumatic solids conveying systems, eg loading of gas streams with pulverized coal in tube or channel systems of coal fired power plants. Background technique [0002] It is known to determine the particle loading of two-phase flows with a gaseous carrier medium in pipe or channel systems by means of microwaves. For this purpose, in quite a number of known solutions, microwaves of a predetermined frequency or a predetermined frequency range are coupled into a conductive section of a tube or channel system prepared as a measurement section and evaluated at the end of the measurement section, Changes...

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Problems solved by technology

However, this has the disadvantage that installing such microwave measuring devices in existing bulk tube or channel systems requires relatively long straight conductive tube or channel segments with constant cross-sectional geometry

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