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Safer flame

A three-year EU-funded project to develop safer brazing has not yet led to the commercial breakthrough the refrigeration and air conditioning industry was hoping for, but the dream is not over, says Bob Towse

An EU research project aimed at developing a safer flame from water has produced some significant technical progress, although the commercial availability of the product has taken a little longer than anticipated.

But Rome wasn’t built in a day and Safeflame actually represents an evolution from almost two centuries of research into developing hydrogen fuel cells, which are only now really emerging as commercially viable applications for buildings.

Not that the next iteration in this vital safety technology will take two centuries.

The work, funded by the EU Seventh Framework Programme and managed by the Research Executive Agency, has shown huge promise.

There are, however, still some significant cost obstacles to be overcome.

Safeflame is a hugely important project and has moved us closer to a safer and more cost-effective way of brazing and soldering.

But more investment is needed to make the product work commercially – specifically investment in manufacturing a unit that engineers and contractors can afford.

The search goes on for different materials and components to make it commercially viable and, ultimately, this must succeed because the current approach using highly flammable bottled gases such as acetylene and propane, contained in high pressure cylinders is inherently unsafe.

There are hundreds of accidents linked to this method every year across the EU and the project team estimated there are around 100,000 different commercial or industrial applications using this ‘conventional’ approach – including refrigeration and air conditioning installation.

Explosion risk

In the UK last year, fire services attended more than 100 incidents caused by acetylene cylinders, which have been known to explode, sending deadly pieces of shrapnel over distances beyond 200 metres.

In addition to the fire and explosion hazards, the force of the shrapnel has been known to penetrate masonry and safety walls.

The great majority of operatives in our sector are well-trained and nine times out of ten they will work safely, but even the best trained people will encounter situations outside of their control.

On top of that, we continue to face a serious skills shortage in this country and there are operators out there prepared to cut corners placing their own employees, clients and members of the public in harm’s way. So this work must go on.

The Safeflame technology has three unique features which have the potential to cut the risk of accidents and the cost of insuring operators, buildings and vehicles:

1) it completely removes the need to store bottled gases;

2) the oxygen and hydrogen are generated separately, and their mixture is controlled to deliver a precise stoichiometric, oxidising or reducing flame – particularly efficient for brazing applications;

3) the length of the flame and the heat flux delivered are easily adjustable, thus giving a more flexible and user-friendly solution.

The prototype device developed from the research programme produces hydrogen and oxygen gases using just water and an electrical input.

These gases can be combusted in a brazing torch to produce a flame that is superior, in many ways, to the one produced by oxy-acetylene and oxy-propane.

The heart of the unit is the electrolyser, which is effectively a fuel cell in reverse that uses the electrical energy to split water into the two gases.

The project succeeded in generating hydrogen and oxygen from water with the gases used as a precisely controlled flame.

The result is a very high temperature and precise flame with uniform heat transfer. The burner itself remains cool to the touch and the process produces hardly anything in the way of harmful emissions.

This method is far less prone to overheating or melting the materials around the brazing point, which improves the finish and quality of the pipework join. It is also much quieter than standard methods.

By removing the need for storing gases, Safeflame reduces explosion hazards while also improving the portability of brazing and soldering equipment.

Often accidents are caused by having gas cylinders stored on building sites or in the back of vans.

The small (suitcase-sized) unit produces a high temperature flame with uniform heat transfer powered from a standard 230V electricity supply – meaning it can simply be plugged into the nearest available socket. This makes the system very easy to use, cheap to run and convenient.

The stumbling block in commercial development so far has been the use of platinum in the membrane.

While platinum is an excellent and highly efficient conducting material, it is, as anyone who has purchased platinum jewellery will know, a rare and thus expensive metal.

The scientists working on the project have spent considerable time looking for an alternative material that can be used to reduce the cost of the finished product.

That work is ongoing and it is critical because, currently, the unit cost is too high for it to be adopted widely by the engineering community.

There is a wider argument about affordability, however.

Currently, refrigeration and air conditioning engineers carry separate oxygen and acetylene bottles for soldering and brazing. 

The cost of compressed gases is increasing and the transportation and storage issues are considerable.

With Safeflame all they need is this single unit, access to electricity and a water supply – they don’t have to buy bottled oxygen at all.

There are also very few moving parts and the simplicity of the design means the unit has an operating life of several years so the Safeflame box will meet the longevity criteria required by busy contractors.

Acetylene ban

Even more persuasive is the fact that many project managers and building owners will no longer allow acetylene onto site. As this becomes increasingly common, an alternative will be urgently needed across the industry.  For all of these reasons, we can be confident that Safeflame will be widely adopted in time.

The Safeflame project leaders also see great potential for this technology in the domestic heating market it may, eventually, be possible to refine the technology to make it suitable for welding as well.

The B&ES played a key role in the Safeflame project by providing expert advice to the research team on practical aspects, such as the preferred size of the units; type of applications; and routes to market. The association also remains committed to seeing the technology move forward.

The building engineering sector’s recent health and safety record is impressive, but we cannot afford to be complacent.

We must continually push technical frontiers to ensure operatives have the very latest devices to deliver projects to a high standard in the safest of environments.

As workloads increase and there is more pressure on operatives to turn projects around quickly, the temptation to take chances will grow. We must be ever more vigilant and always looking for new way to improve safety and efficiency.

Therefore the ambition to produce an inherently safer method of brazing, soldering – and eventually welding – remains as relevant as ever.

Bob Towse is head of technical and safety at the B&ES (Building and Engineering Services Association). He retires this month after almost 50 years in the industry.

The Safeflame project received funding from the EU’s  Seventh Framework Programme For more information, visit www.safeflameproject.eu

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