The subject gives the students the knowledge of working of individual mechanical operations and their significance in chemical industries. With this information, students will be able to control the operation of equipment and regulate production.
1. Characterization of Solid Particles (08 hrs)
Particle shape, particle size, mixed particle sizes and size analysis, expressions for specific surface of mixture, average particle size, number of particles in mixture (expression and meaning of terms only, no derivation)
2. Size Reduction (14 hrs)
i) Energy and power requirements in crushing, mechanical efficiency, expression for power required by machine
ii) Crushing laws: Rittinger’s law, Bond’s law and Kick’s law
iii) Size reduction equipment: classification and names; study of machines: Blake crusher, Jaw crusher, Dodge crusher, Grinding rolls, Single roll toothed crusher, Impact or Attrition mill, Ball mill, Fluid energy mill, Colloid mill, Rotary knife cutter, Flow sheet for closed circuit grinding
3. Mechanical Separation (18 hrs)
i) Screen analysis, Tyler standard screen series, screen effectiveness, Types of screening equipment i.e. gyrating screens, stationary screens and vibrating screens
ii) Filtrations: Classification of filtrations, filter media, filter aids, mechanisms of filtrations, discontinuous Pressure filters, Filter press, Continuous: Vacuum filters, Rotary drum filters, Centrifugal filters; Suspended batch centrifuges.
iii) Separation based on the motion of particles through fluids, Gravity classifiers, Sorting classifiers, Thickeners, Batch sedimentation, rate of sedimentation, centrifugal settling process, Tubular centrifuge, Disk centrifuge.
4. Mixing of Solids: Types of mixers, Ribbon blenders, Double Conemixer, Twin- shell blender. (8 hrs)
LIST OF PRACTICALS
1. To find the sieve analysis of a given sample of solid particles by sieve shaker
2. To determine the grind ability of solids by ball-mill
3. To determine the crushing efficiency by a roll crusher using a sample of solid particles
4. To find the rate of filtration with the help of filter press
5. To perform an experiment on rotary vacuum filter and find rate of filtration
6. To perform an experiment on a cyclone separator and find collection efficiency
7. To perform an experiment on mixer for solid-liquid mixing and find rate of mixing
Mechanical operations has significant importance in the area of chemical engineering. Adequate competency needs to be developed by giving sufficient practical knowledge to mechanical operation (characterization of solid particles, size reduction, energy requirement and mechanical separation). A field visit may be conducted to expose the working of various conveyers and filtration equipment in industries.