Water waste is usually deemed an unwanted, but inevitable by-product of mining processes. Yet trendy pump sealing technology exists which might just about get rid of this waste whereas conserving vitality, improving pump reliability and achieving long term operational savings.
Water is amongst the most vital, and more and more imperilled, sources on earth. That a lot is known and acknowledged by industries across the globe.
However, it’s also one of the most unnecessarily squandered resources in mining operations. And whereas the business has begun to embrace effectivity and sustainability-led advances such as automation and renewable vitality, it remains steadfastly set in its methods when it comes to slurry pump know-how.
Three approaches are routinely specified by pump manufacturers to seal slurry pumps: mechanical packing, expellers (also known as ‘dynamic’ seals’) and single mechanical seals. All come with significant limitations, including poor reliability, decreased mean instances between failure (MTBF), intensive maintenance requirements and higher operational costs.
These components alone should give mine managers trigger 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 management techniques and ISO-50001 Standard for vitality administration systems should pay consideration to the extreme water waste and excessive power consumption that outcomes 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 one of the 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, whereas both single slurry seals and expellers require a provide of cool, clean flush water to be injected into the method at excessive pressure, sustaining a secure fluid movie between the fragile 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 supply and injected into the process at a higher pressure than the stuffing field strain, consistent with the trade 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 impact on the water stability of the plant.
This method constitutes a lack of clean water amounting to billions of gallons a 12 months globally. One giant, conventional 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 shocking statistic by any measure.
At a time when global water supply is predicted to fall wanting demand by some 40% by 20301 , removing unnecessary use of this valuable resource should arguably be a central plank of any accountable sustainability programme. Yet extreme water use, and the higher power consumption it entails, remain embedded in the processes of many mining firms. Worse still, it’s fair to say that it is 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 pointless function of slurry operations as it can be nearly completely eliminated just by employing advanced double mechanical seals and trendy water management help methods.
Improve reliability The type of seal chosen, the surroundings in which it operates, and crucially, the tank assist system which supplies the water to maximise seal life, combine to offer the solution to extreme water waste and energy use.
Modern double mechanical seals have two sets of faces, one sealing to the method fluid and one to ambiance, with a barrier house between the 2. They are designed to fulfill the arduous requirements of heavy responsibility slurry applications, with fortified metallic parts which are highly proof against corrosion and erosion. Large ports and elevated radial clearances imply the lubrication which is important to optimising seal life is maintained continually and persistently.
A pressurised barrier tank system is central to the environmental sustainability of this resolution. เกจวัดความดันpressuregauge employs a thermosiphon process which supplies clean, cool water to the barrier space between the double seals at a pressure higher than the product strain, making certain a constant, steady and clean fluid movie to maintain the seal faces cool and lubricated.
As the mechanical seals generate heat, the new water in the barrier house rises to the tank and is radiated to the environment, allowing the cooler, denser water to sink back down to offer cool lubrication to the seal faces. Most importantly, the flush water is consistently 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’ without the necessity to install particular pump systems, pressurised barrier tanks supply scores as much as 435 psi (30 bar), making them perfect for these applications. Self-topping and self-pressurising, they’re also almost maintenance-free.
Where no plant water provide is out there for topping up the tank methods, or the provision has inadequate stress, fluid supply items can be chosen to produce the barrier fluid to seal faces. These have the added advantages of being ready to supply a water/glycol combination or oil to offer freeze safety in extraordinarily cold climates.
Wide-ranging benefits The advantages of upgrading to fashionable sealing solutions and support systems 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 huge dilution of product, leading to significantly elevated filtration occasions and costs. The pump was sealed with a double mechanical seal designed to satisfy the arduous requirements of the method.
The supporting seal tank system lowered leakage and product dilution to nearly zero. Return on funding was swift and the financial savings long-term. The benefits in terms of water conservation have been equally longlasting and the company’s status enhanced.
The mining trade should take care of a troublesome and dear problem when it comes to maintaining rotating equipment. But the planning, processing and disposal of flush water constitutes an operational and financial burden which is totally avoidable.
And when an organization can remove water waste simultaneously increasing reliability and lowering long run operational prices, the decision to improve to modern methods should surely be an ethical crucial in addition to making sound enterprise sense.
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