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1. 2. 3. 4. Microwave Measuring System, LB 356-456 Micro-Moist. Moisture Content in Coal is an important parameter: Preparation-Regulate Moisture Content Handling-Dust-Ice Transport-Weight Trading-Weight Calorific Value. 5. Microwave Measuring System, LB 356-456 Micro-Moist.
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Microwave Measuring System, LB 356-456 Micro-Moist Moisture Content in Coal is an important parameter: Preparation-Regulate Moisture Content Handling-Dust-Ice Transport-Weight Trading-Weight Calorific Value 5
Microwave Measuring System, LB 356-456 Micro-Moist • Microwave Transmission Techniques are the most accurate • method of determining moisture content of Coal • Attenuation/Area Weight • Phase Shift/Area Weight • Phase Shift and or/Attenuation 6
Microwave Measuring System, LB 356-456 Micro-Moist Attenuation measurement can provide accuracy up to 1wt% moisture Temperature dependence error Bulk Density dependence error Particle size dependent error Conductivity dependent error 7
Microwave Measuring System, LB 456 Micro-Moist Phase Shift Measurement: or (Combined Attenuation and Phase Shift) Independent of Temperature of Coal Independent of Particle Size variations INTEGRAL Area Weight Compensation Accuracy of 0.2 wt% moisture achievable 8
Microwave Measuring System, LB 356-456 Micro-Moist Principle of Operation 9
Microwave Measuring System, LB 354-356-456 Micro-Moist • The choice of 2.7-3.4 GHz frequency range: • Measurement of bulk, not surface. This provides a representative measurement • The temperature coefficient of free water crosses zero at 3 GHz • Attenuation due to ionic conductivity (salt content,…) is reduced at higher • frequencies • Frequency analysis over the frequency range provides phase measurement greater • than 360 deg with plausibility control 10
Microwave Measuring System, LB 356 Micro-Moist Coal Preparation Plant: 12
Microwave Measuring System, LB 356 Micro-Moist Coal Preparation Plant management reported precision of 0.4% moisture (one sigma RMS) 13
Microwave Measuring System, LB 456 Micro-Moist • Product Improvements: • Reference cable can be replaced by short link if Toconstant • PT-100 Temperature Compensation with direct connection • Detector to Evaluation Unit uses FSK (Frequency Shift Keying) 14