Cereal moisture content online device based on dielectric parameters and measurement method using cereal moisture content online device

Abstract

The invention relates to a cereal moisture content online device based on dielectric parameters and a measurement method using the cereal moisture content online device. The cereal moisture content online device comprises a coaxial column-type dielectric parameter measurement sensor and a measure controller, wherein the coaxial column-type dielectric parameter measurement sensor comprises an inner electrode assembly, an outer electrode, a polytetrafluoroethylene insulating layer, a shielding layer and a polytetrafluoroethylene protecting layer which are sequentially and coaxially mounted in a multilayer nesting manner from inside to outside; and the measurement controller is electrically connected with the coaxial column-type dielectric parameter measurement sensor through a double-layer shielding type coaxial cable. According to the cereal moisture content online device, the moisture content of a flowing cereal in a coaxial column-type electrode accommodating cavity is calculated by measuring the dielectric constant epsilon', the dielectric loss epsilon'' and the temperature T of the cereal, and the measurement error caused by the bulk density fluctuation of the cereal in the electrode accommodating cavity is corrected in an application range by virtue of a bulk density correction formula (shown in the description), so that the measurement precision is improved, and the online real-time measurement of the cereal moisture content is realized.

Description

(1) Technical field [0001] The invention relates to an on-line device for grain moisture content based on a dielectric parameter and a measurement method thereof, belonging to the technical field of on-line measurement of grain moisture. (2) Background technology [0002] Grain moisture content is one of the important indicators for grain quality evaluation, and the detection of grain moisture content is of great significance to grain purchase and processing. If the moisture content of the grain is too high, it is easy to cause heat and mildew of the grain, which is not conducive to storage and circulation. However, if the moisture content of the grain is too low, it will affect the quality of the grain and reduce the germination rate of the grain seeds. On-line detection of grain moisture content is one of the bottleneck problems in optimizing grain drying process control and improving grain drying quality. [0003] The detection methods of grain moisture content can be d...

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Problems solved by technology

[0006] Fluctuations in static grain bulk density during static measurement can be corrected by uniform filling methods (such as fixed volume grain free fall filling) and weighing grain weight, but static measurement has poor real-time performance and online weighing of grain weight is difficult under complex working conditions Larger, it is difficult to achieve real-time online real-time measurement of moisture content; in addition to limiting the fluctuation of the grain volume density in the dynamic measurement by controlling the uniformity and stability of the grain flow in the electrode cavity, it is also difficult to further measure the grain weight in the electrode cavity by real-time measurement. fix

[0007] Grain dielectric parameter measurement electrodes mainly include parallel plate electrodes and planar plate electrodes, etc., among which there is an open electric field between the planar plate electrodes, which is easily disturbed by external electromagnetic fields, so it is not suitable for the actual working conditions of on-line detection of grain moisture content

However, the parallel plate electrode is relatively affected by the edge effect, and the grain flow between the parallel plate electrodes is poor, which limits its application in the online detection of grain moisture content.

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