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Being part of the solution

13 October 2019

As the need to conserve water grows, food producers have a real opportunity to become part of the solution, says David Amory

The UK Environment Agency has issued a stark warning that England is in danger of running short of water within 25 years ad similar issues are playing out on a global scale.

While the problem is as much about climate change and population growth as it is about the impact of industrial processes, the predicted outlook is nevertheless dire and the answer has to be collective and concerted action at every level – community, industry and government.

Most food processors are commited to reducing their environmental footprint by embedding sustainability targets in strategies and appointing staff with a focus on sustainability to key senior positions. However, the will to include earnestly stated sustainability policies in business plans and herald them on public-facing web sites is sometimes as far as any concrete action goes. There appears to be an unwillingness to properly investigate, let alone invest in, operational changes to tackle excessive water consumption.

In its recent report, ‘Treading Water,’ the CDP – the global organisation which drives action by companies and governments to safeguard water resources – presented some starkly contrasting facts: while the number of companies setting targets to reduce water withdrawals doubled between 2015 and 2018, in that same period there was an almost 50% rise in the number of companies reporting higher water withdrawals. The food and beverage sector was cited alongside the manufacturing and mineral extraction sectors as one of the worst offenders.

Some food companies seem to be reluctant to consider one of the most simple and cost-effective water saving solutions on the market – the ‘continuous loop’ water management system. This can all but eliminate water waste while at the same time improving reliability and reducing operating costs.

Continuous loop water management
To function correctly the seal faces in a mechanical seal on process pumps need to be flushed with a constant, consistent flow of fluid, often water to ensure they operate efficiently and that dry-running, which causes overheating and ultimately seal failure and pump breakdown – does not occur.

In many applications this fluid is provided from a separate system, and the way this is configured can heavily influence the amount of liquid and energy used.

In a typical ‘flush to drain’ application on a food processing pump, where water is measured for one minute, around 6 to 12 litres of flush water is required to flush seal faces. In continuous operation that amounts to roughly 3.2 to 6.3 million litres per year, for each seal (or pump). Typical food process plants can have hundreds of pumps, resulting in an unacceptable level of waste.

The continuous loop water management system constantly recycles this seal flush water rather than discarding it, reducing waste to around one teaspoonful a day, in the form of vapour. Because the recycled flush water flows across the seal faces in a controlled unbroken supply, this optimises the operating environment, extending seal life and reducing downtime. 

The system can also be retrofitted to legacy equipment. So why aren’t more food processors embracing this solution? 
The most common reason seems to be fear of contamination from bacteria growth in the recycled fluid. Yet a continuous loop barrier fluid vessel has been specifically designed to help ensure that the exacting hygiene standards demanded by the food, drink sector are met. Unlike standard sealed vessels, where access to the interior of the vessel is very limited, this can be disassembled for easy inspection and cleaning. Internal filler welds also minimise the presence of ‘bug traps’ which could allow bacteria to build up and breed.

The explanation that fear of contamination is sufficient to prohibit investment in water-saving systems could also be called into question when the food industry’s response to other potential contamination issues is taken into account.

It’s a fact that mechanical seals are on the market – and in use on food production lines – which fail to meet EU Regulation EC1935/2004. This states that the raw material of every component on any equipment in contact with food must be 100% traceable and that a statement of compliancy must be visibly evidenced on the packaging it comes in. Installing seals which do not comply presents a genuine and serious risk on food production lines but, conversely, this seems to be one contamination risk that some companies are prepared to take. In fact, we have seen mechanical seals made from poisonous antimony carbons, which should only ever be seen in the oil and gas industry, on sites where the implications of them being misapplied could be disastrous.

So, there is good reason to be concerned about the risk of contamination but it might be argued that that concern should be unequivocal across all aspects of food processing operations. The perceived barrier to adopting sustainable water management practices weakens when wrap-round solutions are available which when used correctly present no contamination threat and should in fact enhance hygiene practices and reduce risk.

Dairy application
Take the example of Them Dairy in Denmark, which acted on its commitment to reducing water consumption by replacing the mechanical seals and quench-to-drain support systems on 20 CIP return pumps with dual cartridge mechanical seals and an SW2 EasyClean water management system, which continuously recycles the flush water and can be opened to enable easy inspection and cleaning.

The company achieved a 99.7% reduction in the 1.2 million litres of flush water previously being consumed every year (calculated on 20 pumps running on average for eight hours a day, 260 days a year). The mean time between failure (MTBF) – previously as little as three months due to the damaging impact of dairy products migrating into the barrier fluid as a result of the CIP process – increased to three years. The dairy is confident that bacterial contamination is no longer a risk. Ongoing savings have been achieved through reduced downtime and lower maintenance costs. 

The operational benefits of upgrading to more environmentally sustainable sealing technology is more easily quantified than the enhanced reputation that comes from being able, not just to declare a commitment to the global effort to conserve water, but to evidence it. 

David Amory is global head of marketing at AESSEAL.


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