Water waste is often deemed an undesirable, however inevitable by-product of mining processes. Yet modern pump sealing know-how exists which might nearly remove this waste whereas conserving energy, bettering pump reliability and achieving long run operational savings.
Water is likely considered one of the most vital, and more and more imperilled, assets on earth. That a lot is understood and acknowledged by industries across the globe.
However, additionally it is one of the most unnecessarily squandered resources in mining operations. And whereas the trade has begun to embrace effectivity and sustainability-led advances such as automation and renewable energy, it remains steadfastly set in its ways in relation to slurry pump technology.
Three approaches are routinely specified by pump manufacturers to seal slurry pumps: mechanical packing, expellers (also often recognized as ‘dynamic’ seals’) and single mechanical seals. All come with vital limitations, including poor reliability, reduced imply occasions between failure (MTBF), intensive upkeep necessities and higher operational costs.
These elements alone ought to give mine managers trigger for a re-evaluation of the sealing strategies used on slurry pumps. However, any firm with a dedication to the International Standards Organisation ISO-14001 Standard for environmental administration techniques and ISO-50001 Standard for power management methods should pay consideration to the excessive water waste and excessive power consumption that outcomes from opting for these traditional sealing strategies.
Inefficient sealing When used to seal the process pumps in a mine’s scrubber and floatation circuits, gland packing, single mechanical seals and expeller seals all demand some of the wasteful features of slurry processing which is seal flush water injection.
On gland packed pumps it’s important that packing is flushed with clear water to maintain it cool and lubricated, while each single slurry seals and expellers require a supply of cool, clear flush water to be injected into the process at high stress, 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 supply and injected into the method at a better strain than the stuffing box pressure, according to the industry standard American Petroleum Institute (API) Piping Plan 32. Water which doesn’t leak onto the bottom or into the process is distributed to the tailings dam. This also has an effect on the water balance of the plant.
This method constitutes a lack of clean water amounting to billions of gallons a 12 months globally. One large, conventional slurry pump typically consumes 10 US gallons (37.8 litres) per minute, amounting to five.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 , removing pointless use of this useful resource should arguably be a central plank of any responsible sustainability programme. Yet extreme water use, and the upper vitality consumption it entails, stay embedded in the processes of many mining corporations. Worse still, it’s honest to say that it’s typically accepted as merely ‘par for the course’ by reliability engineers and management alike.
But the fact is that water waste on any scale is a completely pointless feature of slurry operations as it might be virtually totally eliminated simply by using advanced double mechanical seals and fashionable water management support techniques.
Improve reliability The sort of seal selected, the setting during which it operates, and crucially, the tank support system which supplies the water to maximise seal life, combine to offer the solution to extreme water waste and power use.
Modern double mechanical seals have two sets of faces, one sealing to the process fluid and one to ambiance, with a barrier house between the two. They are designed to meet the arduous requirements of heavy obligation slurry applications, with fortified steel elements that are highly resistant to corrosion and erosion. Large ports and increased radial clearances imply the lubrication which is vital to optimising seal life is maintained continually and constantly.
A pressurised barrier tank system is central to the environmental sustainability of this resolution. It employs a thermosiphon process which provides clean, cool water to the barrier house between the double seals at a strain greater than the product stress, making certain a consistent, secure and clean fluid film to keep the seal faces cool and lubricated.
As the mechanical seals generate warmth, the recent water within the barrier area rises to the tank and is radiated to the environment, permitting the cooler, denser water to sink back down to offer cool lubrication to the seal faces. Most importantly, the flush water is continually recycled, flowing across the seal faces in a continuous loop and decreasing leakage to absolutely the minimum, roughly a teaspoonful a day.
While API Plan 32 is unsuitable for servicing multiple slurry pumps in a ‘series train’ with out the want to install special pump techniques, pressurised barrier tanks provide ratings as a lot as 435 psi (30 bar), making them best for these functions. Self-topping and self-pressurising, they are also almost maintenance-free.
Where no plant water supply is available for topping up the tank techniques, or the availability has inadequate stress, fluid delivery units could be selected to supply the barrier fluid to seal faces. These have the added advantages of with the flexibility to supply a water/glycol mixture or oil to offer freeze protection in extremely chilly climates.
Wide-ranging benefits The advantages of upgrading to modern sealing solutions and help methods were 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 large dilution of product, leading to significantly increased filtration instances and prices. The pump was sealed with a double mechanical seal designed to fulfill the arduous necessities of the method.
The supporting seal tank system lowered leakage and product dilution to virtually zero. Return on funding was swift and the savings long-term. The advantages in phrases of water conservation have been equally longlasting and the company’s status enhanced.
The mining industry must take care of a tough and expensive problem in phrases of sustaining rotating tools. But the planning, processing and disposal of flush water constitutes an operational and monetary burden which is totally avoidable.
And when เกจวัดแรงดันน้ำราคา can get rid of water waste simultaneously rising reliability and lowering long run operational costs, the choice to upgrade to modern techniques ought to absolutely be an ethical imperative in addition to making sound business sense.
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