Search results
Results from the WOW.Com Content Network
Stokes' law is the basis of the falling-sphere viscometer, in which the fluid is stationary in a vertical glass tube. A sphere of known size and density is allowed to descend through the liquid. If correctly selected, it reaches terminal velocity, which can be measured by the time it takes to pass two marks on the tube.
In an ideal rectangular sedimentation tank, in the settling zone, the critical particle enters at the top of the settling zone, and the settle velocity would be the smallest value to reach the sludge zone, and at the end of outlet zone, the velocity component of this critical particle are the settling velocity in vertical direction (v s) and in ...
where w is the settling velocity, ρ is density (the subscripts p and f indicate particle and fluid respectively), g is the acceleration due to gravity, r is the radius of the particle and μ is the dynamic viscosity of the fluid. Stokes' law applies when the Reynolds number, Re, of the particle is less than 0.1.
The retention time is the average time that a particulate remains in the clarifier. The turbidity is a measure of cloudiness. Higher values for turbidity removal efficiency correspond to less particulates remaining in the clarified stream. The settling velocity of a particulate can also be determined by using Stokes' law. [17]
The API separator is a gravity separation device designed using Stokes' law principles that define the rise velocity of oil droplets based on their density, size and water properties. The design of the separator is based on the specific gravity difference between the oil and the wastewater because that difference is much smaller than the ...
where is the gravitational constant; is the density of the sediment; is the density of water; is the sediment particle diameter (commonly assumed to be the median particle diameter, often referred to as in field studies); and is the molecular viscosity of water. The Stokes settling velocity can be thought of as the terminal velocity resulting ...
According to Stokes' law, the settling rate increases proportionally with the square of the drop diameter. By promoting coalescence of small water droplets, the settling rate can be greatly increased. The water content is normally reduced to less than 0.5 vol% if this is the final treatment stage before the crude oil is exported.
The particle Reynolds number is important in determining the fall velocity of a particle. When the particle Reynolds number indicates laminar flow, Stokes' law can be used to calculate its fall velocity or settling velocity. When the particle Reynolds number indicates turbulent flow, a turbulent drag law must be constructed to model the ...