UOPS 4 FINALS PART 2 UPDATED TEST
WITH COMPLETE SOLUTION
Applications of settling and sedimentation - ANSWER - removal of solids
from liquid sewage wastes
- settling of crystals from mother liquor
- separation of liquid-liquid mixture from a solvent extraction stage in a
settler
- settling of solid food particles from a liquid food
Sedimentation - ANSWER - the tendency for particles to settle out of the
fluid in which they are entrained and come to rest against a barrier
Factors affecting sedimentation - ANSWER - particle size
- liquid viscosity
- solid and solution density
Types of particles - ANSWER - totally discrete particles
- flocculent particles
, sphericity - ANSWER - surface area of a sphere having the same volume as
the particle per surface area of the particle
Types of sedimentation - ANSWER 1. Free settling
2. Hindered settling
Free settling - ANSWER - when the particle is at a sufficient distance from the
walls of the container and from other particles so that the fall is not affected
by them
Hindered settling - ANSWER - if the motion of the particles is impeded by
other particles, which will happen when the particles are near each other
even though they are not actually colliding
External force - ANSWER - expressed as a product of the mass and the
acceleration of the particle from this force
Forces acting on the body - ANSWER - external force acting downward
- buoyant force acting upward
- resistance or drag force in opposite direction to the particle motion
WITH COMPLETE SOLUTION
Applications of settling and sedimentation - ANSWER - removal of solids
from liquid sewage wastes
- settling of crystals from mother liquor
- separation of liquid-liquid mixture from a solvent extraction stage in a
settler
- settling of solid food particles from a liquid food
Sedimentation - ANSWER - the tendency for particles to settle out of the
fluid in which they are entrained and come to rest against a barrier
Factors affecting sedimentation - ANSWER - particle size
- liquid viscosity
- solid and solution density
Types of particles - ANSWER - totally discrete particles
- flocculent particles
, sphericity - ANSWER - surface area of a sphere having the same volume as
the particle per surface area of the particle
Types of sedimentation - ANSWER 1. Free settling
2. Hindered settling
Free settling - ANSWER - when the particle is at a sufficient distance from the
walls of the container and from other particles so that the fall is not affected
by them
Hindered settling - ANSWER - if the motion of the particles is impeded by
other particles, which will happen when the particles are near each other
even though they are not actually colliding
External force - ANSWER - expressed as a product of the mass and the
acceleration of the particle from this force
Forces acting on the body - ANSWER - external force acting downward
- buoyant force acting upward
- resistance or drag force in opposite direction to the particle motion
