What is significance of dispersion number?
The dispersion number represents the overall extent of axial dispersion in the system under consideration and is the reciprocal of the Peclet number (Pe = unL/Da). In the dispersion number expression, Da is the axial dispersion coefficient, un is the mean velocity and L is the length between the two measurement points.
What is dispersion number of CSTR?
keff = (kkg)1/2.
What is an ideal CSTR?
An ideal CSTR will exhibit well-defined flow behavior that can be characterized by the reactor’s residence time distribution, or exit age distribution. Not all fluid particles will spend the same amount of time within the reactor.
What is dispersion model in CRE?
Dispersion Model. The one parameter to be determined in the dispersion model is the dispersion coefficient, Da. The dispersion model is used most often for non-ideal tubular reactors. The dispersion coefficient can be found by a pulse tracer experiment.
What is dispersion number of reactor?
Vessel dispersion number is defined as: The variance of a continuous distribution measured at a finite number of equidistant locations is given by: (5) Where mean residence time τ is given by: (6) (7)
How is dispersion number calculated?
Add together your differences from the mean and divide by the number of data values you have. In the example, 2.66 plus 0.33 plus 3.33 equals 6.32. Then, 6.32 divided by 3 equals an average deviation of 2.106.
What is the importance of damkohler number?
A Damköhler number (Da) is a useful ratio for determining whether diffusion rates or reaction rates are more ‘important’ for defining a steady-state chemical distribution over the length and time scales of interest.
What are CSTRs used for?
CSTRs are most commonly used in industrial processing, primarily in homogeneous liquid-phase flow reactions where constant agitation is required. However, they are also used in the pharmaceutical industry and for biological processes, such as cell cultures and fermenters.
What is non ideal reactor?
NON-IDEAL REACTORS Definition: reactors do not meet ideal conditions of flow and mixing due. to: Dispersion deviates from ideal plug flow conditions. Short-circuiting and dead spaces deviate from ideal mixing and. plug flow conditions.
What is space velocity in reactor?
In chemical engineering and reactor engineering, space velocity refers to the quotient of the entering volumetric flow rate of the reactants divided by the reactor volume which indicates how many reactor volumes of feed can be treated in a unit time. It is commonly regarded as the reciprocal of the reactor space time.
What is a good coefficient of dispersion?
The International Association of Assessing Officers (2013) states that the performance standard for the coefficient of dispersion is 15% or less for residential properties and 20% or less for commercial properties.