Water waste is often deemed an undesirable, but inevitable by-product of mining processes. Yet modern pump sealing know-how exists which may just about remove this waste whereas conserving energy, bettering pump reliability and achieving long run operational financial savings.
Water is considered one of the most significant, and increasingly imperilled, resources on earth. That much is understood and acknowledged by industries throughout the globe.
However, additionally it is some of the unnecessarily squandered sources in mining operations. And whereas the trade has begun to embrace efficiency and sustainability-led advances corresponding to automation and renewable power, it remains steadfastly set in its methods when it comes to slurry pump know-how.
Three approaches are routinely specified by pump producers to seal slurry pumps: mechanical packing, expellers (also known as ‘dynamic’ seals’) and single mechanical seals. All include important limitations, including poor reliability, decreased mean instances between failure (MTBF), intensive upkeep requirements and better operational costs.
These elements alone should give mine managers cause for a re-evaluation of the sealing strategies used on slurry pumps. However, any company with a dedication to the International Standards Organisation ISO-14001 Standard for environmental administration techniques and ISO-50001 Standard for vitality management systems ought to take observe of the excessive water waste and high power consumption that results 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 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 method at high stress, sustaining a steady fluid movie between the fragile seal faces to keep them cool and lubricated, while forcing the damaging slurry away.
ราคาเกจวัดแรงดันน้ำ required in all three sealing approaches is provided from an exterior supply and injected into the process at a higher strain than the stuffing field pressure, consistent with the business commonplace American Petroleum Institute (API) Piping Plan 32. Water which doesn’t leak onto the ground or into the method is shipped to the tailings dam. This additionally has an effect on the water balance of the plant.
This approach constitutes a lack of clear water amounting to billions of gallons a yr globally. One giant, standard slurry pump typically consumes 10 US gallons (37.eight litres) per minute, amounting to 5.2 million US gallons (19.6 million litres) of water every year – a stunning statistic by any measure.
At a time when global water supply is predicted to fall wanting demand by some 40% by 20301 , eradicating pointless use of this useful useful resource ought to arguably be a central plank of any responsible sustainability programme. Yet excessive water use, and the upper vitality consumption it entails, stay embedded in the processes of many mining companies. Worse still, it’s truthful to say that it is often 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 totally pointless feature of slurry operations as it can be virtually completely eradicated just by using superior double mechanical seals and fashionable water administration help systems.
Improve reliability The sort of seal chosen, the environment by which it operates, and crucially, the tank assist system which provides the water to maximise seal life, mix to offer the answer to extreme water waste and power use.
Modern double mechanical seals have two units of faces, one sealing to the method fluid and one to environment, with a barrier house between the two. They are designed to meet the arduous requirements of heavy responsibility slurry applications, with fortified metal components which are highly resistant to corrosion and erosion. Large ports and increased radial clearances mean the lubrication which is significant to optimising seal life is maintained constantly and persistently.
A pressurised barrier tank system is central to the environmental sustainability of this answer. It employs a thermosiphon process which provides clean, cool water to the barrier house between the double seals at a stress higher than the product stress, ensuring a constant, stable and clean fluid movie to maintain the seal faces cool and lubricated.
As the mechanical seals generate heat, the recent water within the barrier house rises to the tank and is radiated to the environment, allowing the cooler, denser water to sink again down to provide cool lubrication to the seal faces. Most importantly, the flush water is constantly recycled, flowing across the seal faces in a steady loop and reducing 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 necessity to set up particular pump methods, pressurised barrier tanks supply rankings as much as 435 psi (30 bar), making them ideal for these functions. Self-topping and self-pressurising, they’re additionally virtually maintenance-free.
Where no plant water supply is available for topping up the tank techniques, or the supply has inadequate stress, fluid supply units could be selected to provide the barrier fluid to seal faces. These have the added advantages of being ready to supply a water/glycol mixture or oil to supply freeze safety in extraordinarily chilly climates.
Wide-ranging benefits The benefits of upgrading to modern sealing solutions and assist techniques 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, resulting in tremendously increased 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 decreased leakage and product dilution to virtually zero. Return on funding was swift and the savings long-term. The benefits in terms of water conservation have been equally longlasting and the company’s status enhanced.
The mining business should take care of a tough and dear challenge in relation to sustaining rotating gear. But the planning, processing and disposal of flush water constitutes an operational and financial burden which is totally avoidable.
And when an organization can get rid of water waste concurrently increasing reliability and decreasing long run operational prices, the decision to improve to trendy systems should certainly be a moral imperative in addition to making sound enterprise sense.
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