طراحی الکتروسایکلون به کمک مدلسازی عددی به منظور جداسازی میکروذرات در محدوده اندازه معین

نوع مقاله : مقاله پژوهشی

نویسندگان

دانشکده مهندسی مکانیک، دانشگاه بین‌المللی امام خمینی، قزوین، ایران

چکیده

سایکلون‌‌ها برای جداسازی ذرات بزرگتر از جریان سیال مورد استفاده قرار می‌گیرند. در پژوهش پیش رو با اعمال میدان الکتریکی در فاصله بین استوانه داخلی و خارجی سایکلون، امکان استفاده از آن برای جداسازی ذرات با جرم مشخص به صورت عددی مورد بررسی قرار گرفته است. همچنین تأثیر هندسه و شدت میدان الکتریکی اعمال شده بر راندمان جداسازی و قطر ذرات جدا شده از جریان هواپخش ورودی به صورت کمّی ارائه شده‌اند. نتایج نشان داد که تغییر قطر استوانه‌های داخلی و خارجی سایکلون تأثیر کمی بر روی راندمان جداسازی ذرات خواهد داشت. این در حالی است که افزایش طول سایکلون، به خصوص طول استوانه داخلی تأثیر بسیار زیادی بر عملکرد الکتروسایکلون نشان می‌دهد که این پدیده می‌تواند ناشی از افزایش زمان اعمال نیروی الکتریکی به ذرات در داخل سایکلون باشد. با توجه به فاکتور انحراف معیار هندسی در توزیع اندازه ذرات، نتایج نشان داد که دو برابر کردن طول استوانه داخلی سایکلون می‌تواند راندمان جداسازی ذرات را 6% تا 17% افزایش دهد. همچنین با تغییر دبی حجمی هواپخش ورودی به سایکلون و یا تغییر شدت میدان الکتریکی اعمال شده در داخل سایکلون، می‌توان اندازه‌های متفاوتی از ذرات را به وسیله الکترسایکلون از هواپخش جداسازی نمود.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Numerical Simulation of an Electro-Cyclone for Classification of Micron-Sized Particles

نویسندگان [English]

  • Armin Darabi
  • Ali Momenimovahed
Department of Mechanical Engineering, Imam Khomeini International University, Qazvin, Iran.
چکیده [English]

Cyclones are normally used to separate relatively larger particles from the aerosol. In this article, the feasibility of using a cyclone to classify particles in a specific mass range by applying an electric field between the outer cylinder and the vortex finder is studied. Moreover, the effect of cyclone geometry and electric field intensity on the cyclone efficiency and the classified particle diameter is quantified. The finite element method was used for the simulations of 3D, steady, and two-phase flow. It should be noted that the Reynolds number of inlet flow ranged between 4,000 to10,000. The results reveal that the diameters of the inner and outer cylinders have negligible effects on cyclone efficiency. However, an increase in the length of the cyclone specifically the length of the vortex finder can significantly affect the cyclone performance which can be attributed to the higher particle residence time within the cyclone. For cyclones with twice larger cylinders, the classification efficiency is 6% to17% higher based on the geometric standard deviation of the particle size distribution. It was also shown that different particle masses can be classified by adjusting the flow rate of the inlet aerosol or the magnitude of the electric field applied to the charged particles.

کلیدواژه‌ها [English]

  • Electrocyclone
  • Micron-size particles
  • Soot
  • Particle classification
  • Mass
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