September 23, 2017

Fuel cleanliness: The pursuit of zero contamination

Fuel cleanliness and dryness in the supply chain should be all-inclusive approach, from the supplier to the end user’s dispensing points where it is filled into mobile equipment or gensets. And this can be achieved through conducting regular audits to ensure the filtration system’s efficiency.  

One of the overlooked factors in preventative or predictive maintenance of machines in mines is the integrity of the fuel used. Small wonder, high rate of machine failure is frequently experienced, which becomes costly to address, eventually heavily impacting on an organisation’s revenue.

Consequently, to ensure optimal cleanliness of fuel used to power expensive equipment, possible contaminants and how they are likely to penetrate the supply chain has to be established. And only then can measures to preserve quality be implemented.

In an interview with African Mining Brief, Adrian Lane, the managing director of IQ Oil, providers of oil filtration solutions to various industries, singles out the main contaminants as water and particles. Both of which, he says, can stall engine performance through speeding wear and tear of parts. The main parts that are prone to particle wear are fuel injector nozzles, fuel pumps and on-board fuel filters.

Fuel injector nozzle wear results in bad injector spray patterns which in turn reduce engine output and increased fuel consumption. Particles also hasten pump wear.

The above-mentioned scenarios result in the high cost for replacement parts, unplanned downtime which culminates into an irrevocable loss of productivity.

Particle contamination

Particle contamination causes fuel injector wear, resulting in bad injector spray patterns which in turn reduce engine output and increase fuel consumption. It also hastens pump wear.

Additionally, on-board fuel filters, designed to protect the engine’s fuel system from small amounts of particle contamination, are often overwhelmed by the large amounts of dirt present in the diesel.

To demonstrate the burden of replacing parts as a result of particle contamination in diesel, Lane refers to severe cases which can be observed on some African mines. “The particle contamination in diesel is so high that vehicles require fuel filter changes every day compared to every 10-20 days on clean diesel sites. The annual cost for fuel filters alone is astronomical,” he laments.

Water contamination

Water affects engine performance mainly in four ways, says Lane.  “Firstly, water blocks some on-board fuel filters. Secondly, some on-board fuel filters allow the water to pass through and reach the engine, causing damage (severity depending on water percentage). Thirdly, it causes rust, algae, microbial build-up in storage as well as on-board diesel tanks. Cleaning tanks again causes unplanned downtime.

“Also, tanks with a layer of sludge cause continuous problems with the fuel systems on vehicles. Last but not least, water increases the speed of oxidation and degradation of the diesel. Once degraded, the diesel carries soft contaminants which blind fuel filters and cause calcification on fuel injector nozzles,” he says.

Main causes

Though most suppliers and their customers have invested in  filtration equipment to keep contaminants at bay, it has been observed that, somewhere in the course of conveyance, the possibility of contamination, cannot be entirely ruled out. In fact, it is easier for contaminants to infect fuel than usually thought, as Lane points out.

  1. Poorly maintained storage and delivery tanks

“The main source of contamination is poorly maintained storage and delivery tanks of fuel suppliers, poorly maintained delivery tankers and on-site storage tanks of mining companies themselves, which results in sludge build-up throughout the logistics chain.

“Fuel suppliers can deliver dirty fuel, since most customers (mining companies) do not check the quality of the fuel they deliver. Poorly cleaned delivery tankers gather dust every time they empty and refill, contaminating fuel,” points out Lane.

Worse still, he adds, customers do include a precondition which obliges fuel suppliers to deliver diesel which meets cleanliness and dryness requirements. Due to this, he reasons, they spend almost the entire duration of the fuel contract arguing about whose responsibility the problem is rather than solving it.

 (iii) Poor breather systems

Also, contaminants can reach fuel through poor breather systems, or in most cases, complete lack of breather systems on diesel storage tanks, Lane notes. This problem is often overlooked because the physics of what occurs on a daily basis with the diesel tanks is not considered, he stresses.

“Imagine a 300,000 litre fuel tank with a daily consumption of 100,000 litres. Without a decent breather, 100,000 litres of dusty air is sucked into the tank every single day. That dust then settles for a number of hours before the tank is refilled daily, forcing the 100,000 litres of air out again and leaving a lot of the dust behind. The same process is repeated every single day!”

  1. Faulty in-line fuel filters

As usually they handle large amounts of dirt on dispensing points, in-line filters often need to be changed regularly, which turns out to be a costly exercise. And so, the operators seek out a ‘quick-fix’ solution to the frequent filter changes and the associated high costs. “The solution, in many cases, is using much higher micron rated in-line filter elements. However, while this practice drastically reduces the in-line filter change frequency and thus reduces the overall in-line filter cost, at the same time, it allows 95% of the contamination to pass through to the mining vehicles or genset farm,” says Lane.

  1. Poor filtration system audit

More to the point, it has been established that, in the majority of cases, customers continue to struggle with dirty diesel as the filtration system they have invested in is both performance-ineffective and cost-ineffective. This is because they overlook the routine practice of conducting a total audit of the efficiency of installed filtration system – thus, performance of the filter system and the cost of keeping the diesel optimally clean, Lane notes.

“Cost effectiveness of filter elements is a function of filter element price divided by the dirt capacity (in kilograms) of the filter element. In-line filter element solutions cannot provide cost-effectiveness due to very limited dirt capacity, while off-line systems with high dirt capacity filter elements can deliver both performance-effectiveness and cost-effectiveness,” he says.

Accumulated sludge menace

Eventually, dirty fuel results in the formation of sludge in tanks. Sludge, which contains particles, oxidation, microbes and other products, settles at the bottom of tanks – with more contaminants being added daily.  However, it becomes a problem when fuel from a supplier is delivered into a storage tank, observes Lane. “The incoming fuel causes turbulence and stirs accumulated contamination. Before re-settling, the diesel is dispensed to vehicles or genset farms.”

Reluctance to capitalise

It is astounding that customers insist on ineffective in-line filtration solutions rather than recapitalising with modern systems such as CJC off-line depth filtration technology, seeing no value in recapitalising. Lane says customers make the following oversights:

  • They find the upfront costs of these type of systems expensive, instead of looking at the total cost of ownership over 5 or 10 years.
  • Stick with old technology even when its value delivery is poor.
  • Customers do not evaluate properly the true cost of dirty diesel.

In addition, as expected, high commodity prices have caused an attitude change, as can be noticed from massive interest in cost saving technology now that commodity prices are at their lowest levels in many years. Lane rightly puts it: “Complacency around the issue has turned to urgency. Customers want to know how they can spend-to-save.”

Best practice

As long as mining companies spend on wrong solutions, the problem will persist. Due to the fact that the market is flooded with products which fail to deliver, customers have to be wary, Lane cautions. “Customers need to look for suppliers who are willing to guarantee their performance, rather than those simply selling affordable filters,” Lane recommends.

There are no half measures in managing diesel contamination. Specifically, Lane’s sage advice to companies is to consider the following measures:

  • Quality check on all incoming diesel. Customers should perform mandatory standard checks on all incoming ISO code, mg/kg, and water content.
  • Protocol in place to ensure breather equipment functions correctly and us replaced when necessary.
  • Select the right filtration partner who will stand by their value promises and deliver both performance-effectiveness and cost-effectiveness.
  • Regularly draw diesel samples and carry out analysis.
  • For that reason, re-evaluation of the existing filter systems and re-capitalisation of the purification systems is necessary. Investing in the right equipment which can achieve the cleanliness targets and do so with highly cost-effective filter elements is critical

 

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