High-speed particle rotation for coating oil removal by hydrocyclone

Abstract

Hydrocyclone not only realises the centrifugal separation of solids and liquids but also purifies oil-coated particles with their rotational shear flow, resulting in high-speed particle rotation. This study develops a method to detect micro-sphere rotation assisted with microfluidic and high-speed imaging techniques. The method is applied to investigate the intensification mechanism of particle rotation on deoiling oil-coated particles through hydrocyclone. Experimental results show that the highly rotational micro-spheres concentrate in the region approximately 1.5 mm from the side wall and that the strong shear flow near the side wall and particle-wall collision cause the high rotation speed. At experimental conditions, the rotation speed is over 1000 rad/s, which is much larger than that of the isotropic turbulent flow; this speed provides a strong centrifugal force on coating oil. The conical structure of hydrocyclone prevents the axial decrease of tangential velocity, as well as rotation speed, in wall proximity. The magnitude of rotation speed is also significantly affected by inlet flow rate. The deoiling intensification mechanism is attributed to the strong resultant centrifugal force of direction periodically changing that causes by particle rotation and revolution. Experiment on the deoiling of real oil-coated spent catalysts verifies the deoiling intensification of hydrocyclone, that the deoiling efficiency is promoted by at least 12.87% based on stirred hydrothermal tank. This study provides guidance for the design of washing hydrocyclone for oil-coated particles.

Bubble‐separation dynamics in a planar cyclone: Experiments and CFD simulations

“…24 The exposure time was 1/200,000 s. The camera was operated via the Photron FASTCAM Viewer software. 24 The exposure time was 1/200,000 s. The camera was operated via the Photron FASTCAM Viewer software.…”

“…Bubble motion was recorded by a high-speed camera (Photron) fitted with a microlens (AF Micro-Nikkor 60 mm f/2.8D), the same equipment as used in a previous study. 24 The exposure time was 1/200,000 s. The camera was operated via the Photron FASTCAM Viewer software. 25 A white 150-W LED lamp was placed at the back of the planar cyclone.…”

Gas–liquid mass transfer and bubble size distribution in a multi‐Cyclone separator

“…Bubble motion is recorded using a high‐speed camera fitted with a macro lens (AF Nikkor 60 mm f/2.8D Macro), which is same as the one used in the previous study . The exposure time is 5 × 10 −6 s during which the bubbles move less than one pixel.…”

Separação sólido-líquido em hidrociclones otimizados empregando sistemas concentrados e fluido não newtoniano

“…A depender da combinação das dimensões do hidrociclone e das condições operacionais, diferentes empregos são possíveis (SVAROVSKY, 2000). Os hidrociclones podem ser usados para clarificação de líquidos (JANK et al, 2017), espessamento de lamas (GARMSIRI e UNESI, 2018), limpeza de sólidos (HUANG et al, 2017b), classificação por tamanho de partículas (GOLMAEI et al, 2018) et al, (2015) confirmaram os benefícios do uso de hidrociclones em relação a centrífugas na operação de limpeza do óleo de oliva virgem. Além da maior capacidade de operação no novo processo, o produto apresentou qualidade superior tanto em relação à estabilidade do óleo quanto ao nível de antioxidantes e pigmentos presentes.…”

“…No setor petroquímico os hidrociclones são usados em várias etapas: no sistema de controle de sólidos dos fluidos de perfuração (MOGNON et al, 2015), para remoção de óleo em águas de reprocesso (LI e HUANG, 2016) e ainda na limpeza de partículas recobertas com óleo para descarte (HUANG et al, 2017b).…”