Less waste means extra reliability

Water waste is commonly deemed an unwanted, but inevitable by-product of mining processes. Yet modern pump sealing expertise exists which might virtually get rid of this waste while conserving energy, improving pump reliability and attaining long run operational financial savings.
Water is amongst the most vital, and increasingly imperilled, assets on earth. That much is known and acknowledged by industries across the globe.
However, it’s also some of the unnecessarily squandered assets in mining operations. And while the industry has begun to embrace effectivity and sustainability-led advances corresponding to automation and renewable energy, it stays steadfastly set in its methods in relation to slurry pump technology.
Three approaches are routinely specified by pump producers to seal slurry pumps: mechanical packing, expellers (also generally recognized as ‘dynamic’ seals’) and single mechanical seals. All include important limitations, including poor reliability, lowered mean occasions between failure (MTBF), intensive upkeep requirements and better operational costs.
These components alone should give mine managers cause for a re-evaluation of the sealing strategies used on slurry pumps. However, any firm with a commitment to the International Standards Organisation ISO-14001 Standard for environmental administration systems and ISO-50001 Standard for energy administration techniques should pay consideration to the extreme water waste and excessive vitality consumption that outcomes from opting for these traditional sealing methods.
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 some of the wasteful elements of slurry processing which is seal flush water injection.
On gland packed pumps it’s essential that packing is flushed with clean water to keep it cool and lubricated, whereas each single slurry seals and expellers require a provide of cool, clear flush water to be injected into the method at high stress, sustaining a stable fluid film between the delicate seal faces to keep them cool and lubricated, while forcing the damaging slurry away.
The flush water required in all three sealing approaches is provided from an exterior source and injected into the process at a better stress than the stuffing field strain, consistent with the industry standard American Petroleum Institute (API) Piping Plan 32. Water which doesn’t leak onto the ground or into the method is distributed to the tailings dam. This additionally has an impact on the water stability of the plant.
This strategy constitutes a lack of clear water amounting to billions of gallons a 12 months globally. One large, standard slurry pump usually consumes 10 US gallons (37.eight litres) per minute, amounting to five.2 million US gallons (19.6 million litres) of water every year – a shocking statistic by any measure.
At a time when international water provide is predicted to fall short of demand by some 40% by 20301 , removing pointless use of this useful useful resource ought to arguably be a central plank of any accountable sustainability programme. Yet excessive water use, and the higher energy consumption it entails, remain embedded within the processes of many mining corporations. Worse still, it is truthful to say that it’s typically accepted as merely ‘par for the course’ by reliability engineers and administration alike.
But the actual fact is that water waste on any scale is a totally pointless function of slurry operations as it can be almost completely eliminated simply by employing superior double mechanical seals and trendy water management assist methods.
Improve reliability The kind of seal chosen, the environment by which it operates, and crucially, the tank support system which provides the water to maximise seal life, mix to provide the answer to excessive water waste and power use.
Modern double mechanical seals have two units of faces, one sealing to the method fluid and one to ambiance, with a barrier house between the two. They are designed to fulfill the arduous requirements of heavy obligation slurry functions, with fortified metal elements that are highly resistant to corrosion and erosion. เพรสเชอร์เกจ and elevated radial clearances imply the lubrication which is important to optimising seal life is maintained continuously and constantly.
A pressurised barrier tank system is central to the environmental sustainability of this answer. It employs a thermosiphon course of which supplies clear, cool water to the barrier house between the double seals at a strain greater than the product stress, making certain a constant, secure and clear fluid film to keep the seal faces cool and lubricated.
As the mechanical seals generate warmth, the hot water within the barrier area rises to the tank and is radiated to the environment, allowing the cooler, denser water to sink back down to provide cool lubrication to the seal faces. Most importantly, the flush water is continually recycled, flowing across the seal faces in a steady loop and decreasing leakage to absolutely the minimum, roughly a teaspoonful a day.
While API Plan 32 is unsuitable for servicing a number of slurry pumps in a ‘series train’ without the necessity to install special pump methods, pressurised barrier tanks provide ratings as much as 435 psi (30 bar), making them ideal for these purposes. Self-topping and self-pressurising, they are additionally almost maintenance-free.
Where no plant water supply is available for topping up the tank systems, or the provision has insufficient pressure, fluid delivery units can be selected to supply the barrier fluid to seal faces. These have the added benefits of with the ability to provide a water/glycol mixture or oil to offer freeze protection in extraordinarily chilly climates.
Wide-ranging benefits The benefits of upgrading to fashionable sealing options and help systems had 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 tremendously elevated filtration occasions and costs. The pump was sealed with a double mechanical seal designed to meet the arduous necessities of the process.
The supporting seal tank system reduced leakage and product dilution to nearly zero. Return on investment was swift and the savings long-term. The advantages when it comes to water conservation have been equally longlasting and the company’s popularity enhanced.
The mining trade must deal with a tough and dear challenge in phrases of maintaining rotating equipment. But the planning, processing and disposal of flush water constitutes an operational and monetary burden which is totally avoidable.
And when an organization can eliminate water waste concurrently increasing reliability and reducing long run operational costs, the decision to improve to modern systems ought to certainly be a moral crucial as properly as making sound enterprise sense.
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