Water waste is often deemed an unwanted, but inevitable by-product of mining processes. Yet fashionable pump sealing know-how exists which may nearly get rid of this waste while conserving power, improving pump reliability and achieving long run operational savings.
Water is certainly one of the most important, and increasingly imperilled, sources on earth. That a lot is known and acknowledged by industries throughout the globe.
However, it is also some of the unnecessarily squandered assets in mining operations. And while the business has begun to embrace efficiency and sustainability-led advances corresponding to automation and renewable vitality, it stays steadfastly set in its ways in phrases of slurry pump expertise.
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 vital limitations, including poor reliability, reduced mean times between failure (MTBF), intensive maintenance requirements and better operational prices.
These factors alone should give mine managers cause for a re-evaluation of the sealing strategies used on slurry pumps. However, any company with a commitment to the International Standards Organisation ISO-14001 Standard for environmental administration methods and ISO-50001 Standard for power administration techniques should pay attention to the extreme water waste and high power consumption that outcomes from opting for these conventional 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 wasteful aspects of slurry processing which is seal flush water injection.
On gland packed pumps it’s important that packing is flushed with clean water to keep it cool and lubricated, while both single slurry seals and expellers require a provide of cool, clean flush water to be injected into the method at high strain, maintaining a secure fluid film between the fragile seal faces to keep them cool and lubricated, whereas forcing the damaging slurry away.
The flush water required in all three sealing approaches is equipped from an exterior supply and injected into the process at the next pressure than the stuffing box stress, consistent with the business commonplace American Petroleum Institute (API) Piping Plan 32. Water which doesn’t leak onto the bottom or into the method is shipped to the tailings dam. This additionally has an effect on the water stability of the plant.
This approach constitutes a loss of clean water amounting to billions of gallons a 12 months globally. One massive, conventional 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 world water supply is predicted to fall in want of demand by some 40% by 20301 , removing pointless use of this valuable resource should arguably be a central plank of any responsible sustainability programme. Yet extreme water use, and the higher power consumption it entails, stay embedded within the processes of many mining firms. Worse nonetheless, it’s fair to say that it is typically accepted as simply ‘par for the course’ by reliability engineers and administration alike.
But the precise fact is that water waste on any scale is a very pointless feature of slurry operations as it could be virtually completely eradicated simply by employing superior double mechanical seals and trendy water administration assist systems.
Improve reliability The type of seal selected, the setting by which it operates, and crucially, the tank assist system which provides the water to maximise seal life, mix to provide the answer to extreme water waste and vitality use.
Modern double mechanical seals have two sets of faces, one sealing to the process fluid and one to atmosphere, with a barrier area between the 2. They are designed to fulfill the arduous requirements of heavy duty slurry functions, with fortified steel parts that are highly resistant to corrosion and erosion. Large ports and increased radial clearances imply the lubrication which is significant to optimising seal life is maintained continuously and consistently.
A pressurised barrier tank system is central to the environmental sustainability of this solution. It employs a thermosiphon process which provides clear, cool water to the barrier space between the double seals at a pressure greater than the product strain, making certain a consistent, steady and clean fluid movie 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, permitting the cooler, denser water to sink again down to supply cool lubrication to the seal faces. Most importantly, the flush water is continually recycled, flowing throughout the seal faces in a steady loop and reducing leakage to the absolute minimum, roughly a teaspoonful a day.
While API Plan 32 is unsuitable for servicing a quantity of slurry pumps in a ‘series train’ without the want to install particular pump techniques, pressurised barrier tanks offer rankings up to 435 psi (30 bar), making them best for these purposes. Self-topping and self-pressurising, they are additionally almost maintenance-free.
Where เกจวัดอาร์กอน is available for topping up the tank techniques, or the availability has insufficient strain, fluid supply items can be selected to supply the barrier fluid to seal faces. These have the added benefits of being ready to provide a water/glycol combination or oil to offer freeze protection in extremely cold climates.
Wide-ranging advantages The advantages of upgrading to modern sealing solutions and help systems 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 big dilution of product, leading to tremendously elevated filtration occasions and costs. The pump was sealed with a double mechanical seal designed to satisfy the arduous necessities of the method.
The supporting seal tank system reduced leakage and product dilution to just about zero. Return on investment was swift and the savings long-term. The advantages by method of water conservation have been equally longlasting and the company’s reputation enhanced.
The mining industry should cope with a tough and expensive challenge in relation to maintaining rotating gear. But the planning, processing and disposal of flush water constitutes an operational and financial burden which is totally avoidable.
And when a company can get rid of water waste concurrently rising reliability and reducing long term operational prices, the decision to upgrade to fashionable methods ought to absolutely be a moral crucial in addition to making sound enterprise sense.
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