Water waste is commonly deemed an undesirable, however inevitable by-product of mining processes. Yet fashionable pump sealing technology exists which can nearly get rid of this waste while conserving vitality, enhancing pump reliability and achieving long run operational financial savings.
Water is likely certainly one of the most vital, and more and more imperilled, assets on earth. That much is known and acknowledged by industries throughout the globe.
However, additionally it is one of the most unnecessarily squandered assets in mining operations. And while the trade has begun to embrace efficiency and sustainability-led advances corresponding to automation and renewable energy, it remains steadfastly set in its ways in relation 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 significant limitations, including poor reliability, lowered imply instances between failure (MTBF), intensive maintenance necessities and better operational costs.
These components alone ought to give mine managers trigger for a re-evaluation of the sealing methods used on slurry pumps. However, any company with a commitment to the International Standards Organisation ISO-14001 Standard for environmental administration techniques and ISO-50001 Standard for energy management systems ought to pay consideration to the extreme water waste and high vitality consumption that outcomes 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 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 each single slurry seals and expellers require a supply of cool, clean flush water to be injected into the process at excessive stress, sustaining a steady fluid film between the fragile seal faces to keep them cool and lubricated, while forcing the damaging slurry away.
The flush water required in all three sealing approaches is supplied from an external source and injected into the process at a better pressure than the stuffing box pressure, in line with the business standard American Petroleum Institute (API) Piping Plan 32. Water which doesn’t leak onto the bottom or into the method is sent to the tailings dam. This also has an impact on the water steadiness of the plant.
This strategy constitutes a lack of clear water amounting to billions of gallons a 12 months globally. One giant, conventional slurry pump typically consumes 10 US gallons (37.8 litres) per minute, amounting to 5.2 million US gallons (19.6 million litres) of water yearly – a shocking 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 priceless resource ought to arguably be a central plank of any responsible sustainability programme. Yet excessive water use, and the higher vitality consumption it entails, remain 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 management alike.
But the precise fact is that water waste on any scale is a totally pointless function of slurry operations as it could be nearly totally eliminated just by employing superior double mechanical seals and trendy water management support methods.
Improve reliability The type of seal chosen, the setting during which it operates, and crucially, the tank help system which supplies the water to maximise seal life, mix to supply 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 atmosphere, with a barrier space between the two. They are designed to satisfy the arduous necessities of heavy obligation slurry functions, with fortified metal parts that are highly immune to corrosion and erosion. Large ports and increased radial clearances mean 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 solution. It employs a thermosiphon process which supplies clear, cool water to the barrier space between the double seals at a pressure greater than the product stress, making certain a constant, steady and clean fluid movie to keep the seal faces cool and lubricated.
As the mechanical seals generate warmth, the recent water within the barrier house 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 constantly recycled, flowing across the seal faces in a steady loop and decreasing leakage to absolutely the minimum, roughly a teaspoonful a day.
While API Plan 32 is unsuitable for servicing a number of slurry pumps in a ‘series train’ with out the want to install special pump techniques, pressurised barrier tanks offer scores up to 435 psi (30 bar), making them perfect for these purposes. Self-topping and self-pressurising, they are additionally nearly maintenance-free.
Where no plant water provide is available for topping up the tank systems, or the availability has insufficient stress, fluid supply items can be selected to supply the barrier fluid to seal faces. These have the added advantages of being in a position to provide a water/glycol mixture or oil to provide freeze protection in extraordinarily chilly climates.
Wide-ranging benefits The advantages of upgrading to fashionable sealing solutions and support systems have been felt by a coal mine in Poland using a slurry pump to provide 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. pressure gauge หน้าปัด 2 นิ้ว was sealed with a double mechanical seal designed to meet the arduous requirements of the method.
The supporting seal tank system lowered leakage and product dilution to just about zero. Return on ขนาดpressuregauge was swift and the savings long-term. The advantages when it comes to water conservation have been equally longlasting and the company’s status enhanced.
The mining trade should cope with a tricky and expensive challenge in terms of maintaining rotating tools. But the planning, processing and disposal of flush water constitutes an operational and monetary burden which is totally avoidable.
And when a company can eliminate water waste at the same time as increasing reliability and decreasing long term operational prices, the choice to improve to fashionable techniques ought to certainly be an ethical imperative in addition to making sound enterprise sense.
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