Water waste is often deemed an undesirable, but inevitable by-product of mining processes. Yet modern pump sealing technology exists which might just about eliminate this waste whereas conserving vitality, bettering pump reliability and achieving long term operational savings.
Water is among the most important, and increasingly imperilled, sources on earth. That much is known and acknowledged by industries throughout the globe.
However, additionally it is some of the unnecessarily squandered sources in mining operations. And while the industry has begun to embrace efficiency and sustainability-led advances corresponding to automation and renewable power, it remains steadfastly set in its methods in relation to slurry pump expertise.
Three approaches are routinely specified by pump producers to seal slurry pumps: mechanical packing, expellers (also often identified as ‘dynamic’ seals’) and single mechanical seals. All include significant limitations, together with poor reliability, reduced imply times between failure (MTBF), intensive maintenance requirements and better operational prices.
These elements alone should give mine managers trigger for a re-evaluation of the sealing methods used on slurry pumps. However, any company with a dedication to the International Standards Organisation ISO-14001 Standard for environmental management methods and ISO-50001 Standard for power administration techniques ought to take observe of the extreme water waste and excessive vitality consumption that outcomes from opting for these conventional 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 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 process at excessive 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 equipped from an external supply and injected into the process at a higher strain than the stuffing field stress, consistent with the industry normal American Petroleum Institute (API) Piping Plan 32. Water which doesn’t leak onto the ground or into the process is sent to the tailings dam. This additionally has an impact on the water stability of the plant.
This strategy constitutes a loss of clear water amounting to billions of gallons a year globally. One massive, standard 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 every year – a shocking statistic by any measure.
At a time when global water supply is predicted to fall short of demand by some 40% by 20301 , eradicating pointless use of this useful resource ought to arguably be a central plank of any responsible sustainability programme. Yet excessive water use, and the upper energy consumption it entails, remain embedded within the processes of many mining corporations. เกจวัดแรงดัน10bar , it is honest to say that it’s usually accepted as simply ‘par for the course’ by reliability engineers and management alike.
But the very fact is that water waste on any scale is a totally unnecessary function of slurry operations as it can be nearly completely eliminated just by employing advanced double mechanical seals and trendy water management help systems.
Improve reliability The sort of seal selected, the environment during which it operates, and crucially, the tank support system which provides the water to maximise seal life, mix to offer the solution to extreme 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 space between the 2. They are designed to meet the arduous requirements of heavy duty slurry functions, with fortified steel parts which are highly proof against corrosion and erosion. Large ports and elevated radial clearances mean 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 solution. It employs a thermosiphon course of which supplies clean, cool water to the barrier area between the double seals at a pressure larger than the product strain, making certain a consistent, stable and clean fluid movie to keep the seal faces cool and lubricated.
As the mechanical seals generate heat, the recent water in the barrier space rises to the tank and is radiated to the ambiance, allowing the cooler, denser water to sink back down to supply cool lubrication to the seal faces. Most importantly, the flush water is constantly recycled, flowing across the seal faces in a continuous loop and lowering 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’ without the need to set up special pump methods, pressurised barrier tanks offer ratings as much as 435 psi (30 bar), making them ideal for these purposes. Self-topping and self-pressurising, they’re additionally nearly maintenance-free.
Where no plant water provide is available for topping up the tank methods, or the provision has insufficient strain, fluid delivery units may be selected to provide the barrier fluid to seal faces. These have the added benefits of having the ability to provide a water/glycol combination or oil to provide freeze safety in extremely chilly climates.
Wide-ranging benefits The benefits of upgrading to modern sealing options and help systems were felt by a coal mine in Poland using a slurry pump to supply coal mud at 9 bar (135 psi) to filter press. Flushed packing resulted in large dilution of product, leading to tremendously elevated filtration times 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 when it comes to water conservation have been equally longlasting and the company’s reputation enhanced.
The mining industry should deal with a tricky and costly challenge when it comes to sustaining rotating tools. But the planning, processing and disposal of flush water constitutes an operational and monetary burden which is entirely avoidable.
And when an organization can eliminate water waste at the same time as growing reliability and reducing long term operational costs, the choice to improve to trendy systems should certainly be an ethical crucial as nicely as making sound enterprise sense.
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