Water waste is commonly deemed an undesirable, but inevitable by-product of mining processes. Yet fashionable pump sealing know-how exists which might just about get rid of this waste whereas conserving power, bettering pump reliability and attaining long term operational financial savings.
Water is probably certainly one of the most vital, and more and more imperilled, assets on earth. That a lot is known and acknowledged by industries throughout the globe.
However, it’s also one of the unnecessarily squandered sources in mining operations. And whereas the trade has begun to embrace efficiency and sustainability-led advances such as automation and renewable power, it stays 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 come with vital limitations, together with poor reliability, reduced 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 commitment to the International Standards Organisation ISO-14001 Standard for environmental management systems and ISO-50001 Standard for vitality management techniques ought to pay attention to the excessive water waste and high vitality consumption that results 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 most wasteful elements of slurry processing which is seal flush water injection.
On gland packed pumps it’s essential that packing is flushed with clean 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 method at excessive stress, sustaining a stable fluid film between the delicate 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 external supply and injected into the process at a better strain than the stuffing box strain, according to the industry standard 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. This additionally has an effect on the water stability of the plant.
This approach constitutes a lack of clean water amounting to billions of gallons a year globally. One giant, conventional slurry pump sometimes 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 stunning statistic by any measure.
At a time when international water provide is predicted to fall short of demand by some 40% by 20301 , eradicating unnecessary use of this valuable useful resource should arguably be a central plank of any responsible sustainability programme. Yet extreme 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’s usually accepted as merely ‘par for the course’ by reliability engineers and administration alike.
But the fact is that water waste on any scale is a completely pointless feature of slurry operations as it can be nearly totally eradicated simply by employing superior double mechanical seals and fashionable water management help methods.
Improve compound gauge ราคา of seal selected, the surroundings during which it operates, and crucially, the tank help system which supplies the water to maximise seal life, combine to supply the solution to excessive water waste and power use.
Modern double mechanical seals have two sets of faces, one sealing to the process fluid and one to atmosphere, with a barrier area between the two. They are designed to satisfy the arduous necessities of heavy responsibility slurry applications, with fortified metallic elements that are highly resistant to corrosion and erosion. Large ports and increased radial clearances imply the lubrication which is vital to optimising seal life is maintained continuously and persistently.
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 space between the double seals at a stress greater than the product stress, ensuring a consistent, stable and clear fluid film to keep the seal faces cool and lubricated.
As the mechanical seals generate warmth, the recent water in the barrier house rises to the tank and is radiated to the atmosphere, 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 throughout 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 number of slurry pumps in a ‘series train’ with out the necessity to install particular pump methods, pressurised barrier tanks offer rankings as a lot as 435 psi (30 bar), making them ideal for these purposes. Self-topping and self-pressurising, they are also nearly maintenance-free.
Where no plant water provide is out there for topping up the tank methods, or the supply has insufficient stress, fluid supply units could be selected to provide the barrier fluid to seal faces. These have the added advantages of having the power to provide a water/glycol mixture or oil to offer freeze safety in extremely chilly climates.
Wide-ranging advantages The benefits of upgrading to trendy sealing options and assist methods were felt by a coal mine in Poland utilizing a slurry pump to produce coal mud at 9 bar (135 psi) to filter press. Flushed packing resulted in huge dilution of product, resulting in greatly increased filtration times and costs. 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 nearly zero. Return on investment was swift and the savings long-term. The advantages by means of water conservation have been equally longlasting and the company’s status enhanced.
The mining trade must cope with a troublesome and expensive problem 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 get rid of water waste concurrently rising reliability and lowering long term operational prices, the decision to improve to trendy systems should surely be a moral crucial in addition to making sound business sense.