PuK - Process Technology & Components 2024
A technical trade magazine with a history of more than 60 years.
A technical trade magazine with a history of more than 60 years.
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Pumps and Systems<br />
Diaphragm metering pumps<br />
formed by repeating the reactions.<br />
Due to the highly flammable fluids<br />
required, including solvents such as<br />
ethanol, isopropanol, toluene and<br />
acetonitrile, the systems often have<br />
to be designed for use in Ex zone 2 IIB<br />
T3. Inert gas (nitrogen) further protects<br />
the process. The inline dilution<br />
system for aqueous fluid mixtures in<br />
the downstream area provides highaccuracy<br />
buffer solutions for semicontinuous<br />
chromatography after<br />
synthesis. HPLC, ion pairing reversed<br />
phase (IP-RP) and ion exchange (IEX)<br />
chromatography columns are used<br />
for chromatographic purification. 2<br />
Individual dilution tasks can thus<br />
be implemented precisely and flexibly.<br />
Several 1,000 liters of solvent<br />
and aqueous fluids are required per<br />
kilogram of active ingredient. In order<br />
to be able to implement large<br />
adjustment ranges from a few liters<br />
per hour up to 6,000 l/h, it must be<br />
possible to call up an automated<br />
and continuous supply of changing<br />
mixtures for the downstream purification<br />
process via the system control.<br />
Several multi-head diaphragm<br />
metering pumps specially designed<br />
for pharmaceutical applications are<br />
used here. Their phase-shifted drive<br />
charac teristics, typically with three<br />
to five pump heads, enable a lowpulsation<br />
overall flow rate. Thanks<br />
to the back pressure-independent<br />
characteristic curve, the entire metering<br />
and mixing process for oligonucleotide<br />
production is reliably continuous<br />
and absolutely reproducible<br />
at all times. No other type of pump<br />
can achieve stable linear and step<br />
gradients as well as reliable gradient<br />
charac teristics more consistently.<br />
These hermeti cally tight pumps<br />
rule out backflow or plunger packing<br />
problems.<br />
Large adjustment ranges and high<br />
production reliability<br />
Because the production of dilution<br />
solutions sometimes requires very<br />
different flow rates, the systems<br />
must be designed to be flexible. One<br />
practical example required flow rates<br />
of a minimum of 40 l/h and a maximum<br />
of 2,500 l/h. A total of five LEWA<br />
ecodos hygienic diaphragm metering<br />
Fig. 5: Basic flow diagram of a flexible dilution system from concentrates (example). (Source: LEWA)<br />
pumps were integrated into this system<br />
in order to be able to cover this tent, such as the more corrosion-re-<br />
and steels with a higher alloy con-<br />
large adjustment range flexibly. The sistant 1.4529 stainless steel or Hastelloy<br />
for fluids with a high chloride<br />
pump heads are equipped with mechanically<br />
actuated, four-layer sandwich<br />
safety diaphragms. Since the able for metering highly corrosive<br />
content. This makes the pumps suit-<br />
area behind the diaphragm is subject and flammable fluids in oligonucleotide<br />
production over the long term.<br />
to strictly regulated clean room environmental<br />
conditions, contamination The patented four-layer PTFE sandwich<br />
diaphragm also helps here: It<br />
with operating materials or process<br />
fluids cannot occur. Due to the GMP is extremely stable and ensures that<br />
environment, which strives for high operation can be continued safely<br />
even in the event of a diaphragm<br />
integrity with regard to contamination<br />
of any kind, hygienic versions of rupture, thus providing a high level of<br />
the pumps must also be used in this process safety. In an emergency, the<br />
area of downstream processing. This integrated diaphragm rupture signaling<br />
system immediately reports a<br />
goes hand in hand with accep tance<br />
test certificates 3.1 and consis tently corresponding fault during operation<br />
certified construction materials, such without contaminating the rest of the<br />
as FDA, USP or AOF certificates of process line. Only hermetic plunger<br />
conformity. All metal parts in contact diaphragm pumps offer such a high<br />
with the fluid are mechanically and level of production reliability.<br />
additionally electropolished and have<br />
a surface roughness of Ra ≤ 0.5 µm. Precise control and continuous<br />
Thanks to the hygienic design of the monitoring<br />
diaphragm body, which almost completely<br />
eliminates dead spaces, the In terms of control, the use of a servomotor<br />
and an intelligent control sys-<br />
pumps can be cleaned in the CIP process<br />
very easily and without prior dismantling.<br />
requirement profiles to be impletem<br />
enable different customer-side<br />
The EHEDG EL Class 1 certificate<br />
for the ecodos pump type used to be extended up to 1:200. The<br />
mented and the adjustment range<br />
is a decisive proof of quality with regard<br />
to the excellent inline cleanabi-<br />
via the stroke length and the speed<br />
flow rate is traditionally adjusted<br />
lity of the fluid-side pump head. The of the pump motor via the frequency<br />
of an inverter. In newer concepts,<br />
materials used are 1.4435 stainless<br />
steel with a low delta ferrite content the speed of a fanless synchronous<br />
22 PROCESS TECHNOLOGY & COMPONENTS <strong>2024</strong>
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