- 1 - ? ? ? ? ?TP ?AResearch of Pulverized Coal Measurement Technique and Its Application in Blast Furnace Coal Injection SystemYang Gang, Wang Yu-tao (School of Information Science and Engineering, Shenyang, 110004 China Abstract: Mass flow rate measuring of pulverized coal in a pneumatic conveying pipeline is a technique problem. Over the past two decades many different methods and devices have been developed for continuously monitoring the mass flow rate of pulverized coal in a pneumatic pipeline, including: electrostatic, microwave, acoustic and capacitive methods. Firstly, the paper introduces the level of the technology development in this aspect and the current state of the related commercial products. Then a design of a flow meter for blast furnace pulverized coal injection (BFPCI) is introduced. The flow meter has a capacitive phaseconcentration transducer with spiral shaped electrodes. The homogeneous error of the sensitivity distribution in the sensing field is less than 5% by using optimum design, which diminishes the effect of phase distribution and flow regime changes on the measurement. In combination with capacitance based velocity transducer, it can be used to measure the mass f low rate of pulverized coal. The coal flow meter has been used in BFPCI and the performance is good. The whole error is less than 5 % comparing with the electronic scale at work site. Key words: Pneumatic conveying; Mass flow rate; Blast furnace pulverized coal injection; Coal flow meter ? ? ? ?1? ? ?1?2?3?2,3? ? ? ? ? ? ? ? ? ? ?- 2 - ?4? ?5,6? ?7-21? ? ? ? ? ?1.1? ? ? ? ? ? ? ? ? ? ?ABB?PCME?TR-Tech?ESKOMD? ?1?SHAPE * MERGEF ?Fig.1 Installations of electrostatic sensors on coal pipes of power plant? ?-? ? ? ? ?1.2? ?- 3 - ? ? 2? 3?22(? 4 ? 5)?Fig.2 Microwave transceiver for particle concentration measurement ?Fig.3 SWR microwave solid flow meter ? ? ? ?Fig.4 Sensing arrangement using microwave transmitters and receivers?-?4?Fig.5 Installation of the Promecon microwave sensors on a coal pipe ? ?23? ? ?1.3 ? ? ? ?45? ? ? ? ?1.4 ?Physel?beta? ?Greenwich?Teesside?gamma?X-?24,25?6?gamma-?- 4 - ?Fig.6 Radiometric sensing head employing parallel gamma-ray beams ?1.5 ? ? ? ? ? ?Ramsey?Ramsey Granucor?SWR?DensFlow?F.BLOCK?Cabloc?1?1?Table 1 Commercial coal dust flow meter based on variable sensing principle ?ABB?PCME?TR-Tech?ESKOM ?Promecon ?SWR?CSIRO?Physel Beta?SWR?Ramsey ?F.Block?7?Ramsey Granucor?Ramsey Granucor ?7?/?7? ? ? ? ? ?/?Fig.7 The Ramsey Granucor solids flow measurement system ? 8 ? 9 ? DensFlow ? Cabloc?DensFlow DN85/80?Fig.8 Installation of DensFlow DN85/80 coal dust flow meter on a coal pipe of a internal steel corporation ?Fig.9 Cabloc capacitive coal dust flow meter - 5 - ? ?1? ?2? ? ? ? ? ? ? ? ? ? ? ?5%? ?DN133 ?2.1 ? ? ? ? ? ?eff? ?s?g? ?eff?effssggVVVV? (1) ? Vs? Vg? V ? V=Vs+Vg?1? ()()sseffsgsgsgsVVVVVVf VVV? (2) ?V Vs (3) ?)()/(?fKVVfKKCseff? (4) ?K?s?g? C ?1? ? ?2? ? ? ?3? ?Fig.11 Structure of helical capacitance electrode - 6 - ?5,6?(SVP)? 10 ? 4 ? s? d? ? g?g? g ?/?R1?R2?R3?/? ? 41 ?4.18%?2.2 ? ? ? ? ?11 ? ?Fig.11 Output signals from upstream and downstream vector sensor? Ta? Tb?L?V?/)/(LTTLVab? ?5?abTT ?2.3 ?12?, ? ? ?3 %? 5 %?1 %? 3 %?5 % ?26?Fig.12 Coal flow meter for PCI based on capacitance measuring principle ?7 ?15 ? 11 ?26 ?810? ? ? 790?5 %, 20? (5 %?8 % )?3? ? ? ? ? ? ? ? ?“?”?X(t)tY(t)t?TT- 7 - ? ?(References): ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?- 8 - ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?