Applications30

WORLD PUMPS September 2013

www.worldpumps.com

Multi-diaphragm seal-

less pumps for HPLC

Chemical handling

The company saw that the Hydra-Cell concept

is based on a combination of features relevant

to the demands of HPLC but not off ered in

alternative pump designs. Multiple hydrauli-

cally-balanced diaphragms, operating stress-

free throughout the pump’s wide pressure

range, are incorporated in a single head; they

fl ex in sequence to provide the pumping

action, giving virtually pulse-free fl ow. This

arrangement also reduces physical bulk, weight

and footprint and can help reduce overall

system cost.

With no dynamic seals or packings in the pump,

there is no seal wear, avoiding consequential

leaks and sustaining performance at a

consistent level. Other distinctive features

include Wanner’s Kel-Cell diaphragm position

control system which protects the diaphragms

under abnormal inlet conditions, allowing the

pump to run dry indefi nitely without damage.

Two Hydra-Cell models are off ered as standard

equipment in Separlab HPCL systems: the G03

(max fl ow 11.3 l/min at 70 bar) and the G10 (up

to 29 l/min at the same pressure). G10 pumps

are also employed on mobile phase delivery,

with further expansion of the Separlab product

range. Their higher fl ow is needed for columns

of more than 500mm ID.

The company’s high-pressure industrial-scale

separation units are usually built to bespoke

design. The schematic (Figure 1) shows a typical

installed system with Hydra-Cell G10 and G03

pumps.

www.hydra-cell.eu

www.separlab.eu

Separlab Ltd., a Czech Republic specialist

in high-performance liquid chromatog-

raphy (HPLC), has standardised on Wanner

seal-less Hydra-Cell multi-diaphragm pumps

in its industrial-scale systems, using them for

delivering ‘mobile phase’ solvents and injecting

sample mixtures. Hydra-Cell has been preferred

to single-diaphragm and piston-plunger

pumps on these applications.

The Prague-based company processes, designs,

builds and supplies individual products and

complete systems for home and export. It

serves two main market sectors: laboratories

and production plants. In both these areas it

concentrates on preparative and process chro-

matography, rather than analytical. A common

application is purifi cation of a compound in

suffi cient volume for further work, for example

quantitative analysis or use in a process.

Pump specification and performance can

be critical factors in this process. Alongside

high-pressure pumping capability, essential

features include corrosion resistance, a pump’s

ability to produce precise fl ow with no pulsa-

tion and consistency. For HPLC on a larger

industrial scale fl ow rates are higher, but fl ow

must still be pulse-free. Pressure requirements

remain high, while ease and accuracy of pump

control, reliability and easy maintenance are

also important. It was to match and reconcile

these potentially confl icting needs that Sepa-

rlab turned to Hydra-Cell pumps.

Hydra-Cell multi-diaphragm pumps have become the preferred option for Separlab Ltd., a Czech

Republic specialist in high-performance liquid chromatography (HPLC). The company is using

them for delivering ‘mobile phase’ solvents and injecting sample mixture. The company saw that

the Hydra-Cell concept is based on a combination of features relevant to the demands of HPLC

but not off ered in alternative pump designs.

Figure 1. Typical Separlab system for industrial preparatory chromatography

WOPU0813_App_HydraCell 30 31-07-13 10:30:43