V. Shybetskij, V. Povodzinskij

National Technical University of Ukraine

"Kyiv Polytechnic Institute"

 

HYDRODYNAMICS MODELING OF ROLLER FERMENTER FOR CELL CULTURES

 

Cultivation of cell cultures is used in biotechnology for the active pharmaceutical ingredient, a biologically-active substances and in the production of vaccines. Biotechnology of antiviral vaccines almost entirely focused on obtaining full viral antigens using cell lines. In high-volume industrial production cells become damaged by air bubbles and flows of medium.

Creation of fermenters with variable intensity of the culture fluid flows is a critical task of biotechnology.

Roller fermenters often used for cell cultivation. But their design has a number of disadvantages, the main one of which is the low specific capacity (due to the small surface area of immobilization).

To solve this problem, we propose a new fermenter, taking catalytic reactors by the prototype.

          a                           b                          c                          d

Pic. 1. Catalic reactors

a – Berti reactor; b - Robinson-Mahoney reactor with a movable basket;

c - Robinson-Mahoney reactor with a fixed basket; d – Karberry reactor

The fermenter is as follows

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Pic. 2. New Reactor

Its main elements are the body, cassette, process fitting, heat shirt. The head with a large surface area is used for immobilization.

The same conditions as in the Roller must be created in the fermenter for optimal hydrodynamic situation. This is ensured by the speed of rotation and the shear intension. For their determination we should create a mathematical model.

This model based on the Navier-Stokes equation, which is:

                          (1)

                         (2)

After all simplification we have the equation in the canonical form:

                                   (3)

To solve the equation we write the derivative as a difference of velocity values

,             (4)

and rewrite the equation in form:

.               (5)

The value of the shear intension is given by:

.                                           (6)

For numerical values the program was developed in MathCad, and the graphs were drawn.

Pic. 3. Graph of speed

Pic. 4. Graph of shear intension

 

Upon receipt of the limiting values of shear stress, it is possible to realize them on the new fermenter.