PuK - Process Technology & Components 2024

Pumps and Systems
Diaphragm metering pumps
Fig. 2: The inline dilution systems use multihead
diaphragm metering pumps specially
designed for pharmaceutical applications.
(Source: LEWA)
luted to achieve the desired working
concentration. The choice of solution
depends on the subsequent steps in
the downstream process. After the
actual chemical synthesis, in which
the nucleotides are added one after
the other to a growing chain, the
synthesized products undergo what
is known as deprotection and purification
steps to remove unwanted
by-products. Accompanying process
and quality control, e. g. in the form
of mass spectrometry, ensures that
the end product is within the defined
specification window.
Continuous flow regulation
and keep the fluid quantity constant
by controlling the speed of the metering
pumps precisely. Pressure control
valves with integrated electronically
controlled pneumatic damping installed
in the output-side manifold
maintain low fluctuation and keep
the mixing flow almost constant. This
also applies to the pressure: Fluctuations
are undesirable for the built-in
measuring chains and interfere with
the separation processes in the chromatography
columns. Gas phase
components and any temperature increase
also have to be prevented.
After the mixing result is combined
in the manifold, the ratio is analyzed
using appropriate measurement
technology, e. g. via the pH
value and electrical conductivity. After
programming the stored target
values in the higher-level control system,
these are available as different
methods for system control. The recorded
measured values are determined
at a high sampling rate and
continuously evaluated centrally. The
pumps used must be corrosion-resistant,
hygienic and have a robust design
for continuous use. LEWA has detailed
knowledge and many years of
experience in high-precision metering
and mixing thanks to its de cades in
the field of pump supply for the process
chromatography of major OEMs.
And this has also benefited the design
of correspon ding mixing and metering
systems for oligo synthesis customers
for some years now.
Fig. 4: Pressure control valve with damping
properties equipped with an electronic pilot
valve for automatic control.
(Source: EQUILIBAR)
Package units for individual
dilution tasks
The dilution systems designed and
described are not standard systems,
but customized inline metering and
dilution systems that are designed
and constructed as package units
(PU) for the respective downstream
process. A system of this type can
have up to five process inlets and
outlets – sometimes more – as well
as various other connections, for example
for flushing or waste water, to
ensure flexible and continuous fluid
transport. A cycle of chemical reactions
is initiated by feeding in the
respective synthesis fluids. Individual
nucleotides are coupled and the
desired modified chain sequence is
In order to meet increased demand
by expanding production capacities,
precise and continuously operating
inline dilution systems must be provided.
One of the biggest challenges
here is maintaining a consistently reproducible
quality of the required
buffer within the narrow window for
permissible concentration deviations.
Among other things, continuous
monitoring of the flow rates and the
resulting dilution ratios is essential
for this. Therefore, inline dilution systems
typically consist of several channels
with valves, where each channel
is equipped with a multi-head
diaphragm pump and a Coriolis flow
meter. They measure the mass flow
Fig. 3: Pressure control valves with integrated electronically controlled pneumatic damping
installed in the output-side manifold maintain low fluctuation and keep the mixing flow almost
constant. (Source: LEWA)
PROCESS TECHNOLOGY & COMPONENTS 2024
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