Less waste means more reliability

Water waste is often deemed an unwanted, but inevitable by-product of mining processes. Yet fashionable pump sealing technology exists which can just about eliminate this waste whereas conserving vitality, bettering pump reliability and reaching long term operational savings.
Water is among the most significant, and more and more imperilled, resources on earth. That much is understood and acknowledged by industries across the globe.
However, additionally it is one of the unnecessarily squandered assets in mining operations. And whereas the trade has begun to embrace efficiency and sustainability-led advances such as automation and renewable energy, it stays steadfastly set in its ways in phrases of slurry pump know-how.
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, together with poor reliability, lowered imply times between failure (MTBF), intensive upkeep necessities and higher operational prices.
These elements alone ought to 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 systems and ISO-50001 Standard for energy administration techniques ought to take notice of the extreme water waste and high energy consumption that results from choosing 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 one of the most wasteful aspects 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 both single slurry seals and expellers require a provide of cool, clean flush water to be injected into the process at high strain, sustaining a secure fluid movie 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 exterior supply and injected into the method at a higher pressure than the stuffing box strain, consistent with the industry standard American Petroleum Institute (API) Piping Plan 32. Water which doesn’t leak onto the bottom or into the process is sent to the tailings dam. This additionally has an effect on the water stability of the plant.
This approach constitutes a lack of clear water amounting to billions of gallons a year globally. One giant, typical slurry pump sometimes consumes 10 US gallons (37.eight litres) per minute, amounting to five.2 million US gallons (19.6 million litres) of water yearly – a shocking statistic by any measure.
At a time when world water provide is predicted to fall short of demand by some 40% by 20301 , eradicating unnecessary use of this priceless resource should arguably be a central plank of any responsible sustainability programme. Yet extreme water use, and the higher energy consumption it entails, stay embedded within the processes of many mining corporations. Worse still, it’s honest to say that it is typically accepted as simply ‘par for the course’ by reliability engineers and administration alike.
But the actual fact is that water waste on any scale is a completely pointless feature of slurry operations as it may be almost totally eradicated just by using superior double mechanical seals and trendy water administration help systems.
Improve reliability The sort of seal chosen, the surroundings in which it operates, and crucially, the tank assist system which provides the water to maximise seal life, combine to supply the answer to extreme water waste and energy use.
Modern double mechanical seals have two sets of faces, one sealing to the process fluid and one to environment, with a barrier area between the two. They are designed to meet the arduous necessities of heavy responsibility slurry purposes, with fortified metal elements which are extremely immune to corrosion and erosion. Large ports and elevated radial clearances imply the lubrication which is important 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 house between the double seals at a stress higher than the product stress, making certain a consistent, secure and clean fluid movie to maintain the seal faces cool and lubricated.
As the mechanical seals generate warmth, the hot water within the barrier space rises to the tank and is radiated to the atmosphere, permitting the cooler, denser water to sink back down to supply cool lubrication to the seal faces. Most importantly, the flush water is continually recycled, flowing throughout the seal faces in a continuous loop and lowering leakage to absolutely the minimal, 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 special pump techniques, pressurised barrier tanks offer rankings as a lot as 435 psi (30 bar), making them perfect for these applications. 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 insufficient pressure, fluid delivery items can be selected to supply the barrier fluid to seal faces. These have the added advantages of having the ability to supply a water/glycol mixture or oil to provide freeze protection in extremely cold climates.
pressure gauge 2.5 นิ้ว -ranging benefits The benefits of upgrading to trendy sealing solutions and help techniques had been 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, resulting in significantly elevated filtration instances and costs. 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 investment was swift and the financial savings long-term. The benefits by method of water conservation have been equally longlasting and the company’s popularity enhanced.
The mining business should deal with a troublesome and dear challenge in terms of sustaining rotating gear. But the planning, processing and disposal of flush water constitutes an operational and financial burden which is entirely avoidable.
And when a company can get rid of water waste concurrently increasing reliability and lowering long run operational costs, the choice to upgrade to fashionable techniques should surely be an ethical imperative as properly as making sound business sense.
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