DAY 2 UNIT OPS 1 Flashcards
Transformation of a bed of solid particles to a fluid like state through upward drag force
Fluidization
Before the start of fluidization, the bed of particles is termed as ______
fixed bed
Once the drag force balances the weight of the bed, ________ is achieved
Minimum fluidizing velocity
After reaching the terminal settling velocity, where it continues to flow upward even at constant fluid velocity, the bed will become a ______
moblized bed
The bed is ______ if the minimum fluidizing velocity is not met
Fixed
Between minimum fluidizing velocity and terminal settling velocity, the bed is _______
fluidized
Beyond terminal settling velocity, bed is ______
mobilized
Describes how spherical particles are
sphericity
amount of mass per unit bed volume
bulk density
It is the first term of the ergun equation and it accounts for the viscous losses during fluidization and is dominant during laminar flow
Carman-Kozeny equation
Accounts for kinetic energy losses and is dominant during turbulent flow
Burke-Plummer equation (2nd term in ergun equation)
Terminal settling velocity is counteracted by _______
superficial velocity
Separation of a heterogenous mixture or slurry after allowing it to pass through a filter medium
Flitration
The clear liquid that passed through the filter
Filtrate
Solids accumulated on the filter
Filter cake
Rate of filtrate collection can be described by what equation
Ruth Equation
Operation where the filter cake is allowed to accumulate on the medium causing the cake resistance, consequently increase the pressure drop
Constrant Rate Filtration (CRF)
Operation where solids will rapidly form the cake and constant rate filtration will not be experienced
CPF (Constant pressure filtration)
This type of filter operates by applying a higher pressure at the upstream side than the atmospheric pressure of the downstream side
Pressure driven filter
Operate by applying a lower pressure on the downstream side that the atmospheric pressure of the upstream side
Vacuum driven filter type
Most common pressure filter
Plate and frame
most common vacuum filter
rotary vacuum filter
Composed of several filter leaves arranged inside a horizontal tank
Leaf Filter or Shell-and-Leaf Filter
Type of filter that cancbe operated continuously
rotary vacuum filter
Attached knife that is used to scraped off cake in a rotary vacuum filter
Doctor blade
Rotary vacuum filters work under
A. CPF
B. CRF
CPF
Commonly peratins to separation of solid particles of at most 10micrometer by allowing the feed to pass perpendicularly to a very thin membrane area
Membrane separation
Term used to refer to components that were able to pass through the membrane
Permeate
Refers to the components retained by the membrane
Retentate
Solids deposited on the membrane surface
Membrane fouling
rate of permeate extraction per unit area
Flux
Done to control fouling and restore the high flux by reversing the flow of permeate
Backflushing
Membrane separation that can isolate all proteins
Ultrafiltration
Can selectively separate some minerals from the feed
nanofiltration
Operated through the application of relatively high pressure to force the separation of water molecules accross the semi permeable membrane
Reverse osmosis
Type of membrane modules with cluster of porous tubes usually contained in a stainless steel pipe
Tubular
Designed as a series of annular membrane discs sandwiched together by spacer plates
Flat sheet
These are flat membranes enclosed in a central collection tube
Spiral wound
These modules are compact units of fine fiber bundles that can be used to collect permeate either radially inward or outward
Hollow fiber
Separates an aqueous feed with electrolytes into concentrate and diluate through application of an electric field and use of ion selective membranes
Electrodialysis
Equation used to simplify the theories of both batch and continuous filtration
Hagen-Poiseuille Equation
Three major groups of filters
Cake Filter
Clarifying Filters
Cross flow filters
Term commonly used to describe the filtering medium in filtration
Septum
