VERTICAL ROLLER MILL

• Main Authors: ARIMA KENICHI, SUGA HIROSHI, MATSUMOTO SHINJI, DAIMARU TAKUICHIRO, KUSHIOKA KIYONORI
• Format: Patent
• Language: English; Japanese
• Published: 07.05.2015
• Subjects: CRUSHING, PULVERISING, OR DISINTEGRATING; CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN; PERFORMING OPERATIONS; PREPARATORY TREATMENT OF GRAIN FOR MILLING; TRANSPORTING

PROBLEM TO BE SOLVED: To reduce a ratio of coarse particles in pulverized coal of a product in a vertical roller mill equipped with a fixed classifier.SOLUTION: In a vertical roller mill including a cyclone-type fixed classifier 20A provided in a housing 11 for classifying fine powder small in particle diameter by a centrifugal force and discharging the classified fine powder to an outside, the fixed classifier 20A is configured to introduce a solid-gas two-phase flow into an inside from a fixed blade inlet window 22 opening to a cone 21, and to swirl the solid-gas two-phase flow by fixed blades 23 attached near an inside of the fixed blade inlet window 22 so that the fine powder is discharged to the outside from an upper pulverized coal outlet 16 by way of a lower end portion of an inner cylinder 24 provided in the cone 21, and a surface layer 30 is formed on an outer surface of the inner cylinder 24, the surface layer 30 being higher than a surface of an iron plate in a coefficient of restitution of collided particles. 【課題】固定式分級機を備えた竪型ローラミルにおいて、製品微粉炭中の粗粒割合を低減する。【解決手段】粒径の小さい微粉を遠心力により分級して外部へ流出させるサイクロン型の固定式分級機２０Ａをハウジング１１内に備えている竪型ローラミルにおいて、固定式分級機２０Ａは、コーン２１に開口する固定羽根入口窓２２から固気二相流を内部に導入し、固定羽根入口窓２２の内側近傍に取り付けた固定羽根２３で固気二相流に旋回を与えることにより、微粉がコーン２１の内側に設けた内筒２４の下端部側を通って上部の微粉炭出口１６から外部へ流出するように構成され、内筒２４の外表面に、衝突した粒子の反発係数が鉄板表面より高い表面層３０を形成した。【選択図】図１