The latest generation of water purification technology from Purite is enabling Siemens Medical Solutions to ensure the quality of the reagents produced for use with its blood gas analysers
The purity of the water used in the reagents is critical to both the functionality of the diagnostic equipment and, more importantly, the safety of the critically ill patients for which the devices have been developed.
Siemens Medical Solutions provides performance-driven diagnostics that assist in the diagnosis, monitoring and management of disease.
Its products and services incorporate the latest in science and technology to provide healthcare professionals with the vital information they need to deliver more effective, personalised healthcare to patients around the globe.
In particular, the company's blood gas analysers are designed to improve patient care through providing medical professionals with laboratory-quality results at the point of use, enabling them to treat critically ill patients extremely quickly and easily.
Steven Farthing, process engineer at Siemens, highlighted the importance of the pure water in the make up of the reagents for use with the devices, saying that: "The quality of the water used to produce the reagents is essential to the performance and safety of our blood analysers.
"We needed a system capable of producing pharmaceutical grade process water of better than 5uS/cm, in order to achieve consistently accurate results.
"In 2000, after encountering problems with a previous system supplier, we looked around for a new, more reliable solution.
"Following a number of consultations with leading technology providers, we chose Purite, as they offered the right combination of product quality, technical know-how and support".
The Purite system that was installed was specifically developed to deliver the volume and quality of water needed, combining softening, activated carbon filtration, and a double pass RO unit.
The double pass reverse osmosis (RO) system removes greater than 98% of dissolved mineral salts and over 99% of micro-organisms from a pre-treated mains water supply efficiently and effectively, by applying the pressurised water feed to a specialised membrane through which purified water passes with virtually all the micro-organisms and mineral salts being rejected.
The water containing the rejected impurities is then run to drain.
As the feedwater had a high level of bicarbonate alkalinity, Purite also fitted an interstage chemical dosing system to neutralise the carbon dioxide that passed through the first stage of the RO unit.
Dissolved carbon dioxide if left untreated would, due to its low molecular weight, pass through both of the membrane stages and subsequently lower the quality of the final treated water.
In order to achieve the 5us/cm specification the dissolved carbon dioxide had to be removed.
By neutralising the dissolved carbon dioxide and converting it to carbonate the second stage of the membrane process is able to remove it.
The permeate from the RO unit is then fed into a ring main where it is further polished using nuclear grade polishing cylinders, before going into the reagent production process.
This bespoke system allows Siemens to achieve pure water a level of 2-3uS/cm, exceeding their initial requirements.
Steven Farthing is impressed with the results that the company has achieved from the system over the last seven years, "The Purite technology has performed consistently well since installing it in 2000".
"The level of support we have received has been excellent, and Purite service the equipment annually to check that the system continues to run at its optimum performance".
"The quality of the solution ensures we are able to constantly achieve the level of pure water required for the reagents; with this element of the process so critical to the success and safety of our diagnostic devices, the Purite technology continues to prove indispensable to us."
