Less waste means more reliability

Water waste is often deemed an unwanted, but inevitable by-product of mining processes. Yet trendy pump sealing know-how exists which can virtually eliminate this waste while conserving vitality, improving pump reliability and achieving long term operational savings.
Water is amongst the most important, and more and more imperilled, assets on earth. That much is understood and acknowledged by industries across the globe.
However, it is also one of the unnecessarily squandered resources in mining operations. And whereas the business has begun to embrace effectivity and sustainability-led advances similar to automation and renewable vitality, it stays steadfastly set in its ways in relation to slurry pump know-how.
Three approaches are routinely specified by pump producers to seal slurry pumps: mechanical packing, expellers (also often known as ‘dynamic’ seals’) and single mechanical seals. All include significant limitations, including poor reliability, decreased mean instances between failure (MTBF), intensive upkeep requirements and better operational prices.
These factors alone ought to give mine managers cause for a re-evaluation of the sealing methods used on slurry pumps. However, any firm with a dedication to the International Standards Organisation ISO-14001 Standard for environmental management methods and ISO-50001 Standard for vitality administration methods should take observe of the extreme water waste and high energy consumption that outcomes from choosing these traditional sealing strategies.
Inefficient sealing When used to seal the method pumps in a mine’s scrubber and floatation circuits, gland packing, single mechanical seals and expeller seals all demand one of the most wasteful features of slurry processing which is seal flush water injection.
On gland packed pumps it’s essential that packing is flushed with clear water to maintain it cool and lubricated, whereas each single slurry seals and expellers require a provide of cool, clear flush water to be injected into the process at excessive strain, maintaining a steady fluid movie between the fragile seal faces to keep them cool and lubricated, while forcing the damaging slurry away.
The flush water required in all three sealing approaches is supplied from an exterior source and injected into the method at the next stress than the stuffing box strain, consistent with the industry standard American Petroleum Institute (API) Piping Plan 32. Water which doesn’t leak onto the ground or into the process is distributed to the tailings dam. This additionally has an impact on the water balance of the plant.
This strategy constitutes a lack of clear water amounting to billions of gallons a 12 months globally. One giant, typical slurry pump sometimes consumes 10 US gallons (37.8 litres) per minute, amounting to 5.2 million US gallons (19.6 million litres) of water yearly – a surprising statistic by any measure.
At a time when international water provide is predicted to fall short of demand by some 40% by 20301 , eradicating pointless use of this valuable resource should arguably be a central plank of any accountable sustainability programme. Yet excessive water use, and the upper energy consumption it entails, stay embedded in the processes of many mining corporations. Worse still, it’s fair to say that it is typically accepted as merely ‘par for the course’ by reliability engineers and administration alike.
But the precise fact is that water waste on any scale is a totally unnecessary characteristic of slurry operations as it can be nearly totally eliminated simply by employing superior double mechanical seals and trendy water administration support techniques.
Improve reliability The sort of seal chosen, the surroundings in which it operates, and crucially, the tank support system which supplies the water to maximise seal life, combine to provide the solution to excessive water waste and power use.
Modern double mechanical seals have two units of faces, one sealing to the process fluid and one to environment, with a barrier house between the 2. They are designed to satisfy the arduous requirements of heavy responsibility slurry applications, with fortified metal components that are highly proof against corrosion and erosion. Large ports and elevated radial clearances imply the lubrication which is vital to optimising seal life is maintained continually and consistently.
A pressurised barrier tank system is central to the environmental sustainability of this solution. It employs a thermosiphon course of which provides clear, cool water to the barrier house between the double seals at a stress greater than the product pressure, making certain a constant, steady and clear fluid film to maintain the seal faces cool and lubricated.
As the mechanical seals generate heat, the recent water in the barrier house rises to the tank and is radiated to the environment, allowing the cooler, denser water to sink again down to offer cool lubrication to the seal faces. Most importantly, the flush water is consistently recycled, flowing throughout the seal faces in a continuous loop and lowering leakage to the absolute minimum, roughly a teaspoonful a day.
While API Plan 32 is unsuitable for servicing a number of slurry pumps in a ‘series train’ with out the necessity to set up particular pump systems, pressurised barrier tanks supply rankings up to 435 psi (30 bar), making them ideal for these functions. Self-topping and self-pressurising, they’re additionally nearly maintenance-free.
Where no plant water provide is out there for topping up the tank techniques, or the availability has inadequate strain, fluid delivery models may be selected to provide the barrier fluid to seal faces. These have the added benefits of being in a position to provide a water/glycol combination or oil to supply freeze protection in extraordinarily cold climates.
Wide-ranging benefits The benefits of upgrading to fashionable sealing solutions and assist systems have been felt by a coal mine in Poland utilizing a slurry pump to provide coal mud at 9 bar (135 psi) to filter press. Flushed packing resulted in huge dilution of product, leading to greatly elevated filtration instances and prices. The pump was sealed with a double mechanical seal designed to satisfy the arduous necessities of the process.
The supporting seal tank system decreased leakage and product dilution to virtually zero. Return on เครื่องมือวัดpressure was swift and the financial savings long-term. The advantages when it comes to water conservation have been equally longlasting and the company’s status enhanced.
The mining industry must deal with a tough and costly problem in relation to sustaining rotating tools. But the planning, processing and disposal of flush water constitutes an operational and monetary burden which is completely avoidable.
And when an organization can eliminate water waste at the same time as rising reliability and reducing long term operational prices, the choice to upgrade to trendy techniques ought to certainly be a moral crucial in addition to making sound business sense.
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