Defending Against Lime Scale with Military Precision

A regular supply of distilled water is essential in all chemistry laboratories, and the Royal Military College -- also known as Cranfield University -- is no exception, with the chemistry lab producing its own distilled water from domestic water using electrically heated 10 litre stills...

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NOTTINGHAM, UK, May 6, 2009 -- The Royal Military College of Science in Shrivenham, also known as CranfieldUniversity, has long been considered a centre of academic excellence, offering the expertise of both academia and officers of the British Armed Forces in the teaching of Defence Management, Science and Technology.

The RoyalMilitaryCollege’s Centre for Defence Chemistry has an extensive range of well-equipped laboratories offering facilities for all aspects of teaching and research into the chemical sciences.

A regular supply of distilled water is essential in all chemistry laboratories, and the RoyalMilitaryCollege is no exception, with the chemistry lab producing its own distilled water from domestic water using electrically heated 10-litre stills. Being in a hard water area, the scientists at the RoyalMilitaryCollege found that lime scale deposits were building up rapidly on the stills, resulting in them becoming less effective.

To combat the lime scale problem, the stills were regularly dismantled, and acid was used to remove the scale from the glass vessels and heating elements. Repeated acid cleaning, however, was causing damage to the outer metal surface of each element, making it less effective and reducing its life.

Pennwell web 150 176Therefore, the scientists at the RoyalMilitaryCollege turned to non-chemical alternatives to treat the hard water, and finding none they had tested to work effectively, the Hydroflow HS38 unit, from Hydroflow Holdings Ltd. in Nottingham, England, was recommended. The Shrivenham team decided to carry out comparative performance tests, so the distillation unit was installed on a lime scale free still and observations made over a six-week period. The still was then cleaned, re-used for a second six-week period without the Hydroflow HS38, and fresh measurements taken.

The tests confirmed that calcium carbonate crystals formed quickly on heating elements as the water contained more dissolved material than could be held, meaning it was at the point of super-saturation. In comparison, when the Hydroflow HS38 was in operation, crystals grew larger and more quickly, but crystallized onto the floating ‘Hydroflow Crystals’ and remained in suspension as opposed to adhering to the heating element or glass. Furthermore, whilst the HS38 was in use, the water was maintained at saturation point.

Hydropath’s HS38 prevents the build up of all lime scale deposits, including calcium carbonate, by emitting randomly varying electric fields throughout the system. The result is the production of nuclei throughout the water system.

When the water is heated, the resulting precipitate that usually deposits on hot surfaces grows in suspension and develops as a crystal on the nuclei, which is then washed away in the flow. The fields treat the water both up and down stream and will be transmitted into the central heating system to treat the primary water. The treated water is normally able to dissolve existing scale in just a few months.

Since the Hydroflow HS38 eliminated the need for acid cleaning and the still no longer needs to be dismantled, it saves a lot of time for the team at the RoyalMilitaryCollege. The units have now been permanently fitted to all their laboratory stills.


For information about Hydropath’s range of water conditioners, contact +44 (0) 115 986 9966 or visit www.hydroflow.com

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