Measuring Settling Rates and Calculating Thickener Capacity
The required depth of the thickener may be ascertained by computing the capacity of the thickening zone to contain a supply of solids equal to the total capacity of the tank for the number of hours required to thicken the pulp to the density required in the discharge, and to this depth adding an allowance for the lost space due to the pitch of ...
(PDF) Understanding the Thickening Process
particles and the carrier liquid (usually water), enabling the solid particles to settle. As the solids concentration of the slurry increases, the settling rate progressively slows and above a ...
Role of plasticity in the universal scaling of shear-thickening …
A classic example of non-Newtonian flow behavior is the increase in viscosity of dense particulate suspensions under increasing shear stress/shear rate, a phenomenon known as shear thickening (ST) (Barnes 1989; Wagner and Brady 2009).Depending on the particle volume fraction ((phi )), applied stress, and nature of …
Enhancing Gravity Thickener Feedwell Design and
The feeder cup is the main part of the thickener, where the pulp particles are enlarged by the flocculant solution. ... Higher thickener feed flow rate also affected eductor performance, reducing ...
Rake torque versus the feed flow rate.
Separation of particles from liquid in the large gravitational tanks is widely used in mining and industrial wastewater treatment process. Thickener is key unit in the operational processes of ...
Design of a continuous pilot-scale deslime thickener
Thickening is used during two primary mineral processing operations: water removal and desliming. During water removal, the pulp density is increased through the injection of …
Shear thickening in concentrated suspensions
Since most early models for shear thickening were based on hydrodynamics such that the effective viscosity is dominated by the flow in the lubrication gap between particles (Brady and Bossis 1985), it is instructive to highlight a relevant limitation of lubrication models. By relating the lubrication drag force between particles to the size of ...
Shear Thickening of Concentrated Suspensions: Recent …
Shear thickening is the increase of the apparent viscosity as shear rate or shear stress increases. This phenomenon is pronounced in concentrated (dense) suspensions of both colloidal-scale and larger particles, with an abrupt form, known as discontinuous shear thickening, observed as the maximum flowable solid fraction is approached. An …
CFD simulation of tailings slurry thickening in a gravity thickener
The liquid-solid flow in a gravity thickener is modelled by a Two-Fluid Model (TFM). ... It is generally difficult to capture the detailed dynamic behaviors of tailing particles and flow characteristics by a conventional thickening experiment due to the high turbidity of tailings slurry and difficulties in physical measurement ...
(PDF) POPULATION BALANCE
A population balance (PB)-CFD model has been used to describe fluid flow, solids distribution, and aggregation/breakage kinetics of flocculation in gravity thickeners.
Numerical simulation of flocculation and settling behavior of …
Deep cone thickener (DCT) is the key equipment in cemented paste backfill (CPB), so it is essential to study the flocculation settling and thickening characteristics of the whole-tailings in DCT.
EDEM and FLUENT Parameter Finding and Verification Study of Thickener
To improve the concentration performance of the concentrator in the iron ore beneficiation process for iron ore tailings, a coupled simulation analysis of the concentration process was conducted using the discrete element software EDEM (Engineering Discrete Element Method) and the finite element FLUENT software. The volume concentration at …
CFD-PBM modelling of tailings flocculation in a lab-scale gravity thickener
In this investigation, flow visualisation and velocity measurements in a small-scale thickener rake model were undertaken along with computational modelling in order to better understand the flow ...
Normal lubrication force between spherical particles …
In this work, the inverse bi-viscous model [Vázquez-Quesada et al., "Planar channel flow of a discontinuous shear-thickening model fluid: Theory and simulation," Phys. Fluids 29, 103104 (2017)] is used to describe a shear-thickening fluid.An analytical velocity profile in a planar Poiseuille flow is utilized to calculate an approximate solution …
Physics
Seto et al.'s work builds on a relatively new picture in which the dominant force in DST is solid friction between the particles.Three key insights have led to this view. The first is the similarity between DST and the physics of jamming—a phase transition from a liquidlike to a solidlike state that can occur in emulsions, s, and other particle …
Microstructural smoothed particle hydrodynamics model …
Suspensions of both colloidal 1 and non-colloidal 2,3 particles are ubiquitous in industrially relevant flows, 4 and their rich properties have been subject of extensive study. Some dense suspensions of fine non-Brownian particles can exhibit discontinuous shear thickening (DST) behavior, 5 which has been a subject of great interest in the …
(PDF) Flow visualisation and computational prediction in thickener …
In this investigation, flow visualisation and velocity measurements in a small-scale thickener rake model were undertaken along with computational modelling in order to better understand the flow ...
Revealing the frictional transition in shear-thickening …
This situation has improved very recently due to new theoretical and numerical works (7, 8).Because non-Brownian suspensions of hard frictional particles …
Microplastics | Free Full-Text | Separation of Microplastics
Lower flow rates increase the exposure time of particles to the acoustophoretic effects, enhancing particle displacement and separation efficiency. …
Polymers | Free Full-Text | Application of Polymeric CO2 Thickener …
The conventional production technique employed for low-permeability tight reservoirs exhibits limited productivity. To solve the problem, an acetate-type supercritical carbon dioxide (scCO2) thickener, PVE, which contains a large number of microporous structures, was prepared using the atom transfer radical polymerization (ATRP) method. …
THICKENER definition and meaning | Collins English Dictionary
A thickener is a vessel or stage in which gravity brings together suspended solids. A thickener is a piece of equipment in which sedimentation is carried out as a continuous …
Thickening of Mineral Processing Products | SpringerLink
This process mainly consists of clarification of the thickener overflow, thickening of cyclone overflow by the thickener, and centrifugal thickening of thickener bottom flow. For the pulp that has fine particle size or contains large amount of dispersant, pretreatment is needed before thickening, e.g., pH value is adjusted or another additive ...
Thickener
Since the surface area of the thickener is the main variable, the mass flow through the system is considered a flux (the product of concentration and velocity), such as tonnes solids/m 2 /day. Frequently the inverse of this flux is used, called 'unit area', m 2 /tonnes solids/ day. This allows system properties to be described in a general ...
Raking in gravity thickeners
The pilot-scale thickener facility used in this study is a closed loop system and is shown schematically in Fig. 1.A sample of slurry is mixed continuously in a 4.5 m 3 mixing tank, and pumped out of the mixing tank underflow into the pilot thickener. The thickener tank is a 2 m diameter by 2 m high side wall tank with a 14° floor and a small …
Raking in gravity thickeners | Request PDF
In this investigation, flow visualisation and velocity measurements in a small-scale thickener rake model were undertaken along with computational modelling in order to better understand the flow ...
Numerical simulation of shear jamming in a shear thickening …
A shear thickening fluid (STF) is a dense colloidal suspension of submicron particles which exhibits a sudden rise of viscosity by several orders magnitude with an increase in shear rate (Brown and Jaeger 2012; Melrose and Ball 2004; Morris 2009) and achieves a transition from fluid to solid-like behaviour under a strong drive (Fu et al. …
Microstructure of the fluid particles around the rigid body …
In our system, where the rigid bodies were placed in the flow, the velocity distribution of fluid particles located between the two rigid bodies was modified and exhibited fluid–particle ...
Efficiency of raking in gravity thickeners | Semantic Scholar
Semantic Scholar extracted view of "Efficiency of raking in gravity thickeners" by M. Rudman et al. ... In horizontal flow final settling tanks mechanical sludge removal methods are necessary to remove the thickened and stored sludge. ... Science, Chemistry. 1998; A general expression was derived for the shear yield stress of a flocculated ...
Fluid flow in thickener feedwell models
An optically transparent model of a flat-bottomed thickener was constructed to carry out flow visualisation and LDV measurements (shown schematically in Fig. 1). A transparent lid was placed over the thickener model to reduce optical distortion and to support the feedwell and central shaft. ... The gravity thickener, in which particles settle ...
Understanding the Thickening Process
In simple terms, dewatering in a thickener involves gravity acting on the density difference between the solid particles and the carrier liquid (usually water), enabling the solid …