How is kLa measured?

How is kLa measured?

A dynamic method of measuring the volumetric mass transfer coefficient of oxygen, kLa, in gas-liquid reactors is presented which consists in monitoring simultaneously the pressure and oxygen concentration changes. The concentration change due to pressure change is invoked by temporarily closing the gas outlet.

What is kLa in mass transfer?

The kLa (Volumetric Mass Transfer Coefficient) and the OTR (Oxygen Transfer Rate) detail how efficient oxygen is transferred from the gas bubbles into the bioreactor medium, i.e. how much oxygen is available for the cultivated biomass.

What is kLa coefficient?

kLa is a gas transfer coefficient, a measurement of the capacity of the bioreactor to transfer oxygen into the cultures. kLa is influenced by factors such as bioreactor geometry, gas flow, superficial gas velocity, impeller type and speed, and power input for mixing per unit reaction volume.

What is kLa formula?

For 860 mL working volume: KLa (h-1) = 1.5803x liquid speed (cm/sec) Knowing the liquid flow rate as well as the bioreactor type (fixed-bed height, compaction rate, working volume), the liquid flow rate can be easily converted in stirring speed (RPM) using the dedicated application note (Characterization of the liquid …

What is the unit of kLa?

Explanation: In this relation, the volumetric oxygen transfer coefficient, kLa, has the units of mmol, of O2/ml. h. unit concentration gradient. Using the proper concentration units, kLa has the unit of reciprocal of time (i.e., time-1).

What are the units for kLa?

In this relation, the volumetric oxygen transfer coefficient, KLa, has the units of m mol, of O2/ml. h. unit concentration gradient. Using the proper concentration units, KLa has the unit of reciprocal of time (i.e., time-1).

What is the proper concentration unit of kLa?

What is the proper concentration unit of kLa? Explanation: In this relation, the volumetric oxygen transfer coefficient, kLa, has the units of mmol, of O2/ml.

What is unit of kLa?

Does kLa have units?

What is mass transfer process?

Mass transfer is the net movement of mass from one location, usually meaning stream, phase, fraction or component, to another. Mass transfer occurs in many processes, such as absorption, evaporation, drying, precipitation, membrane filtration, and distillation.

What is volumetric mass transfer coefficient?

Volumetric mass transfer coefficient (relative to the unit liquid volume) is one of the most important transport characteristics used in the scale-up, design and performance optimization of mechanically agitated gas-liquid contactors.

What is volumetric mass transfer coefficient (kLa)?

The volumetric mass transfer coefficient (kLa) is a parameter of paramount importance for the design, operation, scale-up and optimization of bioreactors [[1], [2], [3], [4], [5]]. Its reliable calculation has been the subject of extensive studies in the past and a number of different techniques are now available.

What is the mass transfer coefficient of KC?

kc is the mass transfer coefficient [mol/(s·m2)/(mol/m3)], or m/s. n ˙ A {\\displaystyle {\\dot {n}}_{A}} is the mass transfer rate [mol/s] A is the effective mass transfer area [m2] ΔCA is the driving force concentration difference [mol/m3].

What are the units of mass transfer coefficient?

Mass transfer coefficient units. (mol/s)/ (m 2 ·mol/m 3) = m/s. Note, the units will vary based upon which units the driving force is expressed in. The driving force shown here as ‘. Δ c A {\\displaystyle {\\Delta c_ {A}}}.

How do you calculate KLA from dissolved oxygen concentration?

Since the dissolved oxygen concentration, is zero then the KLa may then be calculated from the equation: dCL/ dt = OTR= KLa. C* (i) KLa = OTR/ C* where OTR is the oxygen transfer rate