بررسی ساختار بار درون آسیاهای گردان برای شکل‌های مختلف ذرات با روش اجزای گسسته

بی باک, زهرا; بنیسی, صمد

doi:10.30479/jmre.2021.14442.1461

بررسی ساختار بار درون آسیاهای گردان برای شکل‌های مختلف ذرات با روش اجزای گسسته

نوع مقاله : علمی-پژوهشی

نویسندگان

¹ دانشجوی دکترا، گروه مهندسی معدن، دانشگاه شهید باهنر کرمان، کرمان

² استاد، گروه مهندسی معدن، دانشگاه شهید باهنر کرمان، کرمان

10.30479/jmre.2021.14442.1461

چکیده

روش اجزای گسسته (راگ) با فرض شکل کروی برای ذرات، تاکنون به طور گسترده‌ای برای بررسی حرکت بار در آسیاهای گردان، استفاده شده است. اگرچه فرض کرویت به دلیل پیچیدگی ارایه شکل ذرات غیرکروی و تاثیر بارز آن بر سرعت محاسبات و پیچیدگی تشخیص برخورد بین ذرات است، شبیه‌سازی ذرات با شکل واقعی، به در نظر گرفتن رفتار مکانیکی آن‌ها کمک می‌کند. در این تحقیق، از نرم‌افزار ^©KMPC_DEM، برای شبیه‌سازی حرکت بار استفاده شد. کالیبراسیون پارامترهای ورودی شبیه‌سازی با استفاده از آسیای آزمایشگاهی (با قطر 100 و طول 8_/10 سانتی‌متر) انجام شد. آزمایش‌های کالیبراسیون با گلوله‌های فلزی و مکعب‌های چوبی انجام شدند. پس از کالیبراسیون، شبیه‌سازی‌هایی با شکل‌های مختلف ذرات (کروی، مکعبی و چهاروجهی) برای مطالعه تاثیر شکل ذرات بر ساختار بار انجام شد. مقایسه نتایج شبیه‌سازی با آزمایشگاهی نشان داد که تفاوت بین مقادیر اندازه‌گیری و پیش‌بینی‌ شده برای نقطه برخورد، شانه و پاشنه بار به‌ ترتیب 3، 4 و 5 درجه بود. به دلیل قفل‌شدگی بیشتر ذرات غیرکروی، تفاوت معناداری (17%) بین میزان بار در پرواز ذرات کروی و غیرکروی وجود داشت. نتایج نشان داد که کشیدگی بار با در نظر گرفتن شکل غیرکروی، حدود 5 درجه بیشتر بود. با تغییر شکل ذرات از کروی به غیرکروی، زمان انجام محاسبات برای 20 ثانیه شبیه‌سازی، 35 برابر افزایش یافت.

کلیدواژه‌ها

20.1001.1.25385143.1401.7.2.8.5

عنوان مقاله [English]

An Investigation of Various Particle Shapes Load Structure in Tumbling Mills by DEM Method

نویسندگان [English]

Z. Bibak ¹
S. Banisi ²

¹ P.h.D Student, Kashigar Mineral Processing Research Center, Shahid Bahonar University of Kerman, Kerman, Iran

² Professor, Dept. of Mining Engineering, Shahid Bahonar University of Kerman, Kerman, Iran

چکیده [English]

Load movement in tumbling mills involving spherical particles has been extensively studied with the discrete element method (DEM) in the past. This assumption is legitimized by the added complexity of non-spherical shape representation, contact detection and computational cost. Simulation of particles with realistic shape helps to capture the essential aspects of mechanical behavior of the particulate material. In this research, an in-house developed DEM software called KMPCDEM© was used to simulate the charge movement with spherical and non-spherical particles. At the first to calibrate the model parameters, a model tumbling mill (100 cm diameter and 10.8 cm length) with one transparent end was used. The tests were performed with steel balls and wood cubes. After calibration, a number of mill simulations were performed with the different shape of particles (spherical, cubical, and tetrahedron) to study the effect of particle shape. Comparison of the simulation and experimental results showed that the difference between the measured and predicted impact toe, shoulder angle and bulk toe angles were within 3˚-5˚ of the measured values in the model mill. The amount of in-flight of charge when using spherical and non-spherical particles was significantly different (17%). The marked difference was attributed to higher interlocking of non-spherical particles in comparison to spherical balls. The results showed that the elongation of charge was increased (5o) by considering the non-spherical shape of particles. The simulation computation time increased by 35 times when the shape of particles changed from spherical to cubical.

کلیدواژه‌ها [English]

Discrete element method (DEM)
Tumbling mills
Simulation
Particle shape
Non-spherical particles

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