Production of fine grain limestone by means of focusing and rounding water jets

通过聚焦和圆化水射流生产细粒石灰石

• 批准号: 05555281
• 负责人: SUGAWARA Katsuhiko
• 金额: $ 7.04万
• 依托单位: Kumamoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Developmental Scientific Research (B)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-05555281/
• 关键词: Water jet; Abrasive jet; Fragmentation; Erosion; Coanda nozzle; Rock cutting; Water jet mill; 石灰石; 超徴粉製造; 高速水噴流; 湿式粉砕機; 重質タンカル

In order to make clear the applicability of water jet and abrasive jet of focusing and/or rounding to the fragmentation of limestone, the experimental study has been performed and the fundamental data have been presented for the future design of water jet mill. The present experimental study on the possibility of water jet mill consists of four parts as follows :1. Estimation of incident velocity of water jets by means of impact force measurement.A practical method to evaluate the structure of water jets impinging onto the rock surface has been presented for the clarification of the fracture mechanism of rock. The impact force that is the resultant force imposed upon a plain-target by water jet impinging normally has been analyzed to estimate the incident velocity and the apparenet density of cylindrical water jets.2. Erosion characteristics of rock by water jet impingement.A theory is presented which is applicable to the analysis of erosion process in fragmentation and cutting of rock by a relatively low speed water jet impinging normally onto a rock surface. Both nontraversing and traversing cases are considered.3. Fragmentation performance of abrasive-water jet.Fine grain rocks have been accelerated by cylindrical water jet and impinged against a solid target. The fragmentation performance of fine grain rocks has been analyzed as well as the erosion profile of solid targets : aluminium, mild steel, hard metal, alumina and zirconium.4. Internal flow of coanda nozzle and effect on dispersion of cohesive powders.Coanda nozzle studied in this work is classified as a jet pump with a shape resembling the Laval nozzle. Three-dimensional mean flow has been measured by a single inclined hot-wire anemometer, and it has been clarified that Reynolds stress plays an important roll in dispersing cohesive powders is much greater than the shear stress.

为了弄清水射流和磨料射流聚焦聚圆对石灰石破碎的适用性，进行了实验研究，为今后水射流磨的设计提供了基础数据。本文对水射流磨的可行性进行了实验研究，主要包括以下四个部分：1.通过冲击力测量估算水射流入射速度。为阐明岩石的破裂机理，提出了一种实用的评价水射流冲击岩石表面结构的方法。分析了水射流法向冲击平面目标所受的合力即冲击力，估算了圆柱形水射流的入射速度和表观密度。提出了一种适用于相对低速水射流垂直冲击岩石表面破碎和切割过程中的冲蚀过程分析的理论。同时考虑了非遍历和遍历两种情况。磨料水射流的破碎性能：圆柱形水射流加速了细粒岩石的破碎，并撞击了固体目标。分析了细粒岩石的破碎性能以及铝、碳钢、硬质合金、氧化铝和锆等固体靶材的侵蚀分布。Coanda喷嘴内部流动及对粘性粉末分散的影响本文研究的Coanda喷嘴是一种喷射泵，其形状类似于拉瓦尔喷嘴。用单倾斜热线风速仪对三维平均流进行了测量，结果表明雷诺应力在粘性粉末的分散中起着重要的作用，比剪切应力大得多。

项目成果

K.Sugawara: Introduction to Rock Mechanics, participate in Chapter 6. Industrial Publishing & Consulting, Inc., 1994

K.Sukawara：岩石力学导论，参与第6章。工业出版

H.Ohba, I.Honda, H.Nakayama, H.Miyamoto, O.Nagaoka and T.Ishikawa: "Internal Flow of Coanda Nozzle and Effect on Dispersion of Cohesive Powders" Trans, JSME (B). Vol.60, No.578. 15-19 (1994)

H.Ohba、I.Honda、H.Nakayama、H.Miyamoto、O.Nagaoka 和 T.Ishikawa：“附壁喷嘴的内部流动及其对粘性粉末分散的影响”Trans，JSME (B)。

Y.Obara, T.Nakayama, M.Akimoto and H.Okamura: "Coupled boundary element-characteristics method and its application to elest-plastic problems." Proc.of Int.Symp.on Assessment and Prevention of Failure Phenomena in Rock Engineering. 927-933 (1993)

Y.Obara、T.Nakayama、M.Akimoto 和 H.Okamura：“耦合边界元特征方法及其在弹性塑性问题中的应用。”

T.Nakayama, K.Imai: "Size Distribution Analysis of Rock Fragmentation with Blasting by means of Image Processing (1st Report)" Journal of Limestone. Vol.271. 39-47 (1994)

T.Nakayama、K.Imai：“通过图像处理进行爆破岩石破碎的尺寸分布分析（第 1 份报告）”《石灰石杂志》。

K.Sugawara and Y.Obara: Comprehensive Rock Engineering, Vol.3, participate in Chapter of In Situ Stress. Pergamon Press, 1993

K.Sukawara 和 Y.Obara：综合岩石工程，Vol.3，参与地应力章节。