Fuel preparation technology – the latest safety considerations

Kuchl, 15.11.2017

The specifications for new fuel preparation technologies are becoming increasingly sophisticated, as industry innovation continues apace. But when it comes to investing in waste shredders that help manufacture cement fuels, which criteria should top the procurement wish-list in 2018? With more than 25 years’ experience in this sector, Peter Streinik, head of UNTHA’s waste shredding division, offers his thoughts.

Investing in a new capital asset is never a straightforward exercise. There are, indisputably, performance criteria to fulfil, and typically such factors are of primary importance when drawing up a technological shortlist – the procured equipment must be fit for purpose after all. When it comes to fuel preparation technology such as a shredder, these criteria typically include evidenced uptime statistics, throughput rates, particle sizing homogeneity and foreign object protection mechanisms. All will influence the capacity of the resulting plant and the quality of the cement fuel it is able to produce.

There are then fiscal considerations to accommodate. Only a few years ago, when the aftermath of the global economic crisis was still extremely raw, a large proportion of investments were cost driven. Now, on the other hand, whilst commercial viability still needs to be carefully scrutinised, savvier alternative fuel manufacturers are looking beyond the initial price tag of a machine in favour of assessing the whole life costs of the asset. This involves the calculation of slightly more complex – yet far more meaningful – sums, which factor in the ongoing costs of maintenance, wear and power consumption, to name just a few. Armed with these figures, it is then possible to truly understand the likely fiscal drain – or yield – of the machine, and the anticipated return on investment period. Financial packages – often inclusive of service and maintenance – have further opened up the market.


The rising safety challenge

Thankfully, in the last five years, safety factors have also risen to the forefront of operators’ minds. A previous Global Cement article (Tackling alternative fuel production fires – October 2015) specifically highlighted the need to adopt greater fire mitigation strategies within feedstock preparation lines. Some shredder manufacturers were quick to respond, having already engineered greater fire safety mechanisms into their technology, by design.

As a result, anti-explosive Atex-specification motors, plus slow speed rotors that generate far less dust than those with higher tip speeds, are just two of the features that began to be demanded by operators, as standard.

Carefully positioned UV, infrared, heat and spark detectors on inlet hoppers and discharge conveyors have also been increasingly sought. In the event of a significant temperature increase, these sensors – which sit adjacent to strategically located extinguishing nozzles – can automatically trigger a controlled amount of water spray onto the targeted area. This means that, if the risk is within the shredder, the materials can be cooled and/or the fire doused, before any hot glowing fractions can propagate. Alarms can even be activated to alert the operator to commence a manual extinguishing process, and/or automatically notify the fire brigade.


2018 safety considerations

Whilst these performance, finance and fire safety considerations mean that a shredder wish-list has become far more sophisticated than it was a few years ago, procurement criteria should evolve further still if operators are considering an investment in 2018 or beyond.

Noise will come to the forefront like never before. Some cement fuel manufacturers have previously considered noise in respect of the potential debilitating damage to employee wellbeing – and this duty of care requirement is only going to escalate.

Admittedly in some parts of the world such as the Far East, noise minimisation is less of a priority. However, given most plants seek long-lasting equipment, it seems prudent to future-proof the investment. Certainly, in Western Europe and the US, as legislation becomes increasingly stringent, the need to protect operators’ hearing is non-negotiable. Fuel manufacturers should therefore seek to invest in shredding technology that runs below the first action point – 80dB(A). Not only, ethically, is this the right thing to do, but heightened wellbeing strategies also typically reduce stress levels and boost productivity too, as noisy distractions and the constant drone of equipment is lessened.


The noise debate grows louder

But the noise debate is growing louder still, as highlighted in a recent article in the UK Chartered Institution of Wastes Management (CIWM) journal. The Environment Agency spoke openly about the difficulties that can be encountered between ‘waste’ plants and their neighbouring communities, if disgruntled members of the public object to excessive noise levels.

Operators therefore need to address the noise pollution they create, particularly if planning permission is to be sought for the build of new production lines or extended/multi-shift operating hours. If noise obligations continue to be ignored, permits will simply not be granted. Noise considerations don’t just encompass the shredding technology of course – every piece of equipment, even down to the in-feed kit, needs to be assessed. Sometimes even simple improvements to the door of a plant, can aid soundproofing.


Dust pollution mitigation = benefits for all

In a similar vein, communities are – quite rightly – pushing back on alternative fuel production plants that create excess dust pollution, which means regulatory authorities will have to take greater action as 2018 unfolds.

However, in facilities where dust does pose an issue, operators should welcome – rather than dread – the push to improve the cleanliness of their sites.

Reduced dust levels will inevitably help to placate neighbours, whilst consequently bringing about operational benefits too. The fire risk of the plant will also immediately drop, and employees’ health will improve if fewer dust particles are airborne.

Yet, from a commercial perspective, steps to moderate dust can – perhaps inadvertently – result in a better quality fuel too, not to mention increased margins. Slower speed, higher torque shredders will – by design – produce less dust without compromising throughputs.

Furthermore, such technology will create up to 80% less fines. Because fines are non-specification dust-like particles that cannot be mixed with cement fuels, they are usually simply screened off and sent to landfill. But in high capacity plants this can result in disposal costs in excess of £1m, not to mention an adverse environmental impact of a process that is supposed to support the world’s renewable energy strategy. Avoid the production of these fines in the first place, however, and disposal cost savings of £800,000 will soon accelerate the return on investment from the shredder and the break-even point of the wider plant.

In truth, many technological innovations can generate both safety and commercial benefits. So, whilst the business case for improved safety considerations should not need any further rationalisation, there are, in truth, multiple advantages associated with more considered shredder procurement.

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