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Less waste means more reliability

Water waste is often deemed an unwanted, but inevitable by-product of mining processes. Yet trendy pump sealing know-how exists which can just about get rid of this waste whereas conserving energy, enhancing pump reliability and achieving long term operational savings.
Water is among the most important, and increasingly imperilled, assets on earth. That a lot is understood and acknowledged by industries across the globe.
However, it is also some of the unnecessarily squandered assets in mining operations. And whereas the business has begun to embrace efficiency and sustainability-led advances such as automation and renewable power, it remains steadfastly set in its methods in relation to slurry pump expertise.
Three approaches are routinely specified by pump manufacturers to seal slurry pumps: mechanical packing, expellers (also generally known as ‘dynamic’ seals’) and single mechanical seals. All include significant limitations, together with poor reliability, lowered mean occasions between failure (MTBF), intensive maintenance requirements and better operational prices.
These elements 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 management systems and ISO-50001 Standard for energy administration methods should take note of the excessive water waste and high vitality 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 some 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 clean 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 strain, sustaining a stable fluid film 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 external source and injected into the method at a better stress than the stuffing box pressure, according to the industry normal American Petroleum Institute (API) Piping Plan 32. Water which doesn’t leak onto the ground or into the process is shipped to the tailings dam. This also has an impact on the water balance of the plant.
This strategy constitutes a lack of clean water amounting to billions of gallons a 12 months globally. One giant, typical 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 every year – a surprising statistic by any measure.
At a time when international water provide is predicted to fall in need of demand by some 40% by 20301 , removing pointless use of this valuable useful resource ought to arguably be a central plank of any responsible sustainability programme. Yet extreme water use, and the higher power consumption it entails, remain embedded within the processes of many mining companies. Worse nonetheless, it is honest to say that it’s often 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 unnecessary feature of slurry operations as it can be nearly completely eradicated just by using superior double mechanical seals and fashionable water administration assist methods.
Improve reliability The type of seal chosen, the setting by which it operates, and crucially, the tank assist system which supplies the water to maximise seal life, mix to provide the answer to excessive 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 obligation slurry purposes, with fortified metal components that are highly resistant to corrosion and erosion. Large ports and increased radial clearances mean the lubrication which is vital to optimising seal life is maintained constantly and constantly.
A pressurised barrier tank system is central to the environmental sustainability of this solution. It employs a thermosiphon course of which supplies clean, cool water to the barrier space between the double seals at a strain greater than the product stress, ensuring a consistent, steady and clear fluid movie to maintain the seal faces cool and lubricated.
As compound gauge ราคา generate heat, the new water in the barrier space rises to the tank and is radiated to the atmosphere, allowing the cooler, denser water to sink back down to offer cool lubrication to the seal faces. Most importantly, the flush water is continually recycled, flowing throughout the seal faces in a steady loop and reducing leakage to absolutely the minimal, roughly a teaspoonful a day.
While API Plan 32 is unsuitable for servicing a number of slurry pumps in a ‘series train’ without the need to install special pump techniques, pressurised barrier tanks supply rankings up to 435 psi (30 bar), making them perfect for these functions. Self-topping and self-pressurising, they’re also nearly maintenance-free.
Where no plant water supply is available for topping up the tank techniques, or the provision has insufficient stress, fluid supply models could be selected to supply the barrier fluid to seal faces. These have the added advantages of having the flexibility to provide a water/glycol combination or oil to provide freeze protection in extraordinarily chilly climates.
Wide-ranging advantages The benefits of upgrading to modern sealing options and support systems had 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 huge dilution of product, resulting in greatly increased filtration instances and prices. The pump was sealed with a double mechanical seal designed to satisfy the arduous necessities of the process.
The supporting seal tank system lowered leakage and product dilution to virtually zero. Return on investment was swift and the savings long-term. The benefits by method of water conservation have been equally longlasting and the company’s popularity enhanced.
The mining business must take care of a tricky and expensive problem in terms of maintaining 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 remove water waste concurrently growing reliability and reducing long run operational prices, the decision to improve to trendy techniques should certainly be a moral imperative in addition to making sound enterprise sense.
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