Less waste means extra reliability

Water waste is commonly deemed an unwanted, but inevitable by-product of mining processes. Yet trendy pump sealing expertise exists which may nearly eliminate this waste whereas conserving vitality, bettering pump reliability and attaining long run operational savings.
Water is one of the most vital, and increasingly imperilled, resources on earth. That a lot is understood and acknowledged by industries throughout the globe.
However, it’s also one of the unnecessarily squandered resources in mining operations. And whereas the trade has begun to embrace efficiency and sustainability-led advances similar to automation and renewable vitality, it stays steadfastly set in its methods in terms of 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 come with significant limitations, together with poor reliability, decreased imply occasions between failure (MTBF), intensive upkeep necessities and higher operational prices.
These elements alone ought to 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 administration techniques and ISO-50001 Standard for vitality administration methods ought to take observe of the excessive water waste and excessive energy consumption that outcomes from opting for these conventional 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 elements of slurry processing which is seal flush water injection.
On gland packed pumps it’s important that packing is flushed with clean 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 process at high stress, sustaining a secure fluid movie between the fragile seal faces to maintain them cool and lubricated, while forcing the damaging slurry away.
The flush water required in all three sealing approaches is equipped from an exterior source and injected into the method at the next strain than the stuffing box pressure, according to the trade normal American Petroleum Institute (API) Piping Plan 32. Water which doesn’t leak onto the ground or into the method is shipped to the tailings dam. เครื่องมือที่ใช้วัดความดันโลหิต has an effect on the water steadiness of the plant.
This approach constitutes a lack of clear water amounting to billions of gallons a yr globally. One massive, standard slurry pump usually 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 international water provide is predicted to fall in need of demand by some 40% by 20301 , removing unnecessary use of this valuable resource ought to arguably be a central plank of any accountable sustainability programme. Yet extreme water use, and the higher energy consumption it entails, remain embedded within the processes of many mining companies. Worse nonetheless, it’s honest to say that it’s typically accepted as merely ‘par for the course’ by reliability engineers and management alike.
But the actual fact is that water waste on any scale is a totally pointless function of slurry operations as it can be virtually completely eliminated just by using advanced double mechanical seals and trendy water management help techniques.
Improve reliability The sort of seal selected, the environment in which it operates, and crucially, the tank assist system which supplies the water to maximise seal life, combine to supply the answer to extreme water waste and vitality use.
Modern double mechanical seals have two units of faces, one sealing to the method fluid and one to environment, with a barrier space between the two. They are designed to satisfy the arduous requirements of heavy responsibility slurry purposes, with fortified metal components which are extremely proof against corrosion and erosion. Large ports and increased radial clearances mean the lubrication which is vital to optimising seal life is maintained constantly 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 area between the double seals at a strain higher 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 within the barrier space rises to the tank and is radiated to the environment, permitting the cooler, denser water to sink back down to provide cool lubrication to the seal faces. Most importantly, the flush water is consistently recycled, flowing across the seal faces in a steady loop and reducing leakage to the absolute minimum, roughly a teaspoonful a day.
While API Plan 32 is unsuitable for servicing a quantity of slurry pumps in a ‘series train’ without the need to install particular pump systems, pressurised barrier tanks provide rankings up to 435 psi (30 bar), making them best for these applications. Self-topping and self-pressurising, they are also almost maintenance-free.
Where no plant water provide is on the market for topping up the tank methods, or the supply has insufficient pressure, fluid delivery items could be chosen to provide the barrier fluid to seal faces. These have the added advantages of with the flexibility to provide a water/glycol mixture or oil to offer freeze safety in extraordinarily cold climates.
Wide-ranging advantages The advantages of upgrading to trendy sealing options and assist methods 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 huge dilution of product, leading to greatly elevated filtration times and prices. The pump was sealed with a double mechanical seal designed to meet the arduous necessities of the method.
The supporting seal tank system decreased leakage and product dilution to nearly zero. Return on investment was swift and the savings long-term. The benefits in terms of water conservation have been equally longlasting and the company’s popularity enhanced.
The mining industry must deal with a troublesome and costly challenge in relation to sustaining rotating tools. But the planning, processing and disposal of flush water constitutes an operational and financial burden which is totally avoidable.
And when a company can remove water waste concurrently increasing reliability and lowering long run operational costs, the choice to upgrade to modern techniques should certainly be an ethical crucial in addition to making sound business sense.
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