MECHANICAL SEPARATIONS - Chemical Engineering …chemicalengineeringdocuments.weebly.co… · PPT...
Transcript of MECHANICAL SEPARATIONS - Chemical Engineering …chemicalengineeringdocuments.weebly.co… · PPT...
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Course Outline
Introduction to Separation Processes Role of Mechanical Separations in Chemical
Engineering Fundamentals of different mechanical separations;
Filtration, Sedimentation, Clarification, Flotation, Centrifugal separations, Jigging, tabling, magnetic and electrostatic separations, Sonic Agglomeration
Different types of mechanical separation equipment
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Introduction to Separation Processes
Separation process is used to transform a mixture of substances into two or more distinct products.
The mixture can be a combination of any two or more states: solid-solid, solid-liquid, solid-gas, liquid-liquid, liquid-gas, gas-gas, solid-liquid-gas mixture, etc.
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How separation is carried out?
In order to affect a separation, separating agents are needed in the form of either:
Energy input (heat, electricity, magnetism,) Withdrawal of energy ( cooling, freezing) Medium (filter, membrane, screens) May be any phase as well as any chemical
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Classification of Separation processes
The classification can be based on the means of separation;1. Mechanical Processes2. Chemical processes
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Why Separations are needed?
Isolating valuable chemicals from mixtures Removing impurities from raw materials Purification of products
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Mechanical Separations
Mechanical Separations are applicable to heterogeneous mixtures, not to homogenous solutions. The techniques are based on the physical differences b/w the particles such as size, shape or density.
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Relatively less Energy Requirements
Ease of Operation
Ease of Maintenance
No special Feed pretreatment required
Not applicable for separating Components in homogeneous phase
Not versatile i.e. in same state may be one element can be separated
and other don’t.
Applicable to low flow rates
Advantages
Disadvantages
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Classification On the basis of characteristics
Depending on the difference in size or shape Depending on the difference in phase density Depending on fluid and particle mechanics Depending on surface, electrical or magnetic properties
On the basis of phases involved S-S L-L G-L L-G S-L L-S S-G
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Our focus will be the…
Solid – Solid Separation Solid – Liquid Separation Solid – Gas Separation
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Objective – to separate the mixture of solids into two or more fractions
Dry basis Screening Electrostatic
magnetic
Wet basis Classification
Solid – Solid Separation
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Objective – to separate the solids and liquid from each other
Filtration
Sedimentation – gravitational settling Centrifugal separators
Solid – Liquid Separation
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Objective – to separate the solids from gas
Filtration
Gravitational settling Centrifugation
Solid – Gas Separation