Sparging and Mass Transfer from Gases to Liquids
In bioreactor and fermentor systems, optimal mass transfer
of gases like oxygen or carbon dioxide is perhaps the most
difficult task to accomplish. Oxygen, in particular, is poorly
soluble in water - and even less in cell culture and fermentation
broths. Oxygen transfer is aided by agitation used to
mix nutrients and to keep the cell culture or fermentation
homogeneous. There are limits to agitation speed due to
high power consumption as well as damage to organisms
resulting from excessive tip speed. Agitation alone does not
provide adequate mass transfer.
Using a Mott porous metal sparger greatly increases
mass transfer rates in bioreactors and fermentors. The
introduction of gases into stirred or unstirred reactor vessels
via millions of tiny bubbles increases the gas-to-liquid
contact areas allowing for optimal mass transfer rates. In-tank
applications, with sparging elements located inside the tank,
can be batch or continuous flow, with or without agitation.
Quick Change Spargers* Provide Fast
and Easy Installation and Validation
In the past Mott porous metal sparger elements, or "frits"
as they are sometimes called, were welded to the end
of sparger assemblies. This fixed method of attachment
required either a cut and re-weld method of replacement
or a clean out-of-place method for the entire sparger
assembly to meet GMP validation methods.
Today, Mott offers a Quick Change Sparger that reduces the
time and effort to replace the porous metal sparger element.
With the Quick Change Sparger system (see figure 2), the
porous metal element can be removed and replaced after
each use. Eliminating the need to re-weld the tip or clean
the entire assembly. After each batch, a new tip can be
installed on the end of the assembly and is ready for steam
in place operation. Or the sparger tip can be cleaned out of
place utilizing a number of methods including ultrasonic
cleaning or detergent and water flush.
Either way, the Quick Change Sparger can help make
sparger change out simple and easy. Changing to new
clean sparger tips after each batch provides an excellent
method of maintaining GMP process validation methods.
* Patent Pending