Water waste is often deemed an undesirable, but inevitable by-product of mining processes. Yet modern pump sealing technology exists which might nearly remove this waste while conserving energy, bettering pump reliability and achieving long run operational financial savings.
Water is probably considered one of the most significant, and increasingly imperilled, assets on earth. That much is understood and acknowledged by industries across the globe.
However, additionally it is some of the unnecessarily squandered resources in mining operations. And while the business has begun to embrace effectivity and sustainability-led advances such as automation and renewable energy, it stays steadfastly set in its ways when it comes to slurry pump know-how.
Three approaches are routinely specified by pump manufacturers to seal slurry pumps: mechanical packing, expellers (also generally identified as ‘dynamic’ seals’) and single mechanical seals. All include significant limitations, together with poor reliability, lowered mean instances between failure (MTBF), intensive upkeep necessities and higher 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 dedication to the International Standards Organisation ISO-14001 Standard for environmental administration techniques and ISO-50001 Standard for power management methods should pay attention to the excessive water waste and high power consumption that results from choosing 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 one of the most 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 maintain it cool and lubricated, whereas each single slurry seals and expellers require a supply of cool, clear flush water to be injected into the method at high pressure, maintaining a steady fluid movie between the delicate seal faces to maintain them cool and lubricated, whereas forcing the damaging slurry away.
The flush water required in all three sealing approaches is provided from an exterior source and injected into the method at a better stress than the stuffing field strain, in line with the business commonplace 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. เกจวัดแรงดันภาษาอังกฤษ has an impact on the water balance of the plant.
This strategy constitutes a loss of clear water amounting to billions of gallons a yr globally. One large, typical slurry pump typically 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 surprising statistic by any measure.
At a time when global water provide is predicted to fall in want of demand by some 40% by 20301 , eradicating pointless use of this priceless useful resource ought to arguably be a central plank of any responsible sustainability programme. Yet excessive water use, and the upper power consumption it entails, remain embedded within the processes of many mining corporations. Worse still, it is honest to say that it is usually accepted as simply ‘par for the course’ by reliability engineers and administration alike.
But the very fact is that water waste on any scale is a completely unnecessary characteristic of slurry operations as it can be virtually totally eliminated just by using superior double mechanical seals and fashionable water administration support techniques.
Improve reliability The sort of seal chosen, the surroundings in 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 environment, with a barrier area between the two. They are designed to fulfill the arduous requirements of heavy obligation slurry functions, with fortified steel elements which are extremely immune to corrosion and erosion. Large ports and increased radial clearances imply the lubrication which is important 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 supplies clean, cool water to the barrier area between the double seals at a strain greater than the product pressure, guaranteeing a consistent, steady and clear fluid film to maintain the seal faces cool and lubricated.
As the mechanical seals generate heat, the new water in the barrier area rises to the tank and is radiated to the environment, allowing the cooler, denser water to sink again down to offer cool lubrication to the seal faces. Most importantly, the flush water is constantly recycled, flowing throughout the seal faces in a steady loop and decreasing leakage to the absolute minimal, roughly a teaspoonful a day.
While API Plan 32 is unsuitable for servicing a quantity of slurry pumps in a ‘series train’ with out the want to set up particular pump methods, pressurised barrier tanks provide scores as a lot as 435 psi (30 bar), making them ideal for these functions. Self-topping and self-pressurising, they’re additionally almost maintenance-free.
Where no plant water supply is available for topping up the tank techniques, or the provision has insufficient pressure, fluid delivery units can be chosen to supply the barrier fluid to seal faces. These have the added advantages of with the ability to provide a water/glycol mixture or oil to supply freeze safety in extraordinarily chilly climates.
Wide-ranging advantages The advantages of upgrading to trendy sealing options and help systems had been felt by a coal mine in Poland using a slurry pump to produce coal mud at 9 bar (135 psi) to filter press. Flushed packing resulted in big dilution of product, leading to tremendously increased filtration times and costs. The pump was sealed with a double mechanical seal designed to satisfy the arduous necessities of the process.
The supporting seal tank system reduced leakage and product dilution to just about zero. Return on funding was swift and the financial savings long-term. The advantages in terms of water conservation have been equally longlasting and the company’s popularity enhanced.
The mining business should deal with a tricky and expensive challenge in terms 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 an organization can eliminate water waste at the same time as increasing reliability and lowering long term operational costs, the choice to improve to fashionable techniques ought to absolutely be a moral crucial as well as making sound business sense.
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