Water waste is commonly deemed an undesirable, but inevitable by-product of mining processes. Yet modern pump sealing expertise exists which might just about remove this waste while conserving power, bettering pump reliability and reaching long term operational financial savings.
Water is probably certainly one of the most vital, and more and more imperilled, resources on earth. That a lot is understood and acknowledged by industries throughout the globe.
However, it is also one of the unnecessarily squandered assets in mining operations. And while the business has begun to embrace efficiency and sustainability-led advances similar to automation and renewable power, it stays steadfastly set in its ways in relation to slurry pump technology.
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 important limitations, together with poor reliability, decreased mean occasions between failure (MTBF), intensive maintenance 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 company with a commitment to the International Standards Organisation ISO-14001 Standard for environmental administration methods and ISO-50001 Standard for energy management techniques ought to pay consideration to the extreme water waste and high vitality consumption that results from opting for 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 one of the most 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, while both single slurry seals and expellers require a supply of cool, clean flush water to be injected into the method at excessive pressure, sustaining a secure 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 supplied from an external supply and injected into the method at a better pressure than the stuffing field strain, according to the industry standard American Petroleum Institute (API) Piping Plan 32. Water which doesn’t leak onto the bottom or into the method is distributed to the tailings dam. This also has an impact on the water balance of the plant.
This strategy constitutes a lack of clear water amounting to billions of gallons a year globally. One massive, standard slurry pump usually consumes 10 US gallons (37.eight litres) per minute, amounting to 5.2 million US gallons (19.6 million litres) of water yearly – a surprising statistic by any measure.
At a time when global water provide is predicted to fall short of demand by some 40% by 20301 , eradicating pointless use of this valuable resource should arguably be a central plank of any accountable sustainability programme. Yet extreme water use, and the upper vitality consumption it entails, stay embedded within the processes of many mining firms. Worse still, it’s truthful to say that it is often accepted as simply ‘par for the course’ by reliability engineers and management alike.
But the fact is that water waste on any scale is a totally unnecessary feature of slurry operations as it may be nearly totally eliminated simply by using advanced double mechanical seals and trendy water management support techniques.
Improve reliability The sort of seal chosen, the environment during which it operates, and crucially, the tank support system which supplies the water to maximise seal life, combine to provide the solution to extreme water waste and energy use.
Modern double mechanical seals have two units of faces, one sealing to the method fluid and one to ambiance, with a barrier house between the 2. They are designed to satisfy the arduous necessities of heavy obligation slurry purposes, with fortified metallic components which are extremely immune to corrosion and erosion. Large ports and increased radial clearances imply the lubrication which is important to optimising seal life is maintained continually and consistently.
เกจ์แรงดัน is central to the environmental sustainability of this answer. It employs a thermosiphon course of which supplies clean, cool water to the barrier house between the double seals at a pressure larger than the product stress, ensuring a constant, secure and clean fluid movie to keep the seal faces cool and lubricated.
As the mechanical seals generate warmth, the recent water in the barrier area rises to the tank and is radiated to the ambiance, allowing the cooler, denser water to sink again down to provide cool lubrication to the seal faces. Most importantly, the flush water is constantly recycled, flowing throughout the seal faces in a continuous loop and reducing leakage to the absolute minimal, roughly a teaspoonful a day.
While API Plan 32 is unsuitable for servicing multiple slurry pumps in a ‘series train’ with out the need to set up particular pump methods, pressurised barrier tanks supply rankings up to 435 psi (30 bar), making them best for these functions. Self-topping and self-pressurising, they are also nearly maintenance-free.
Where no plant water supply is on the market for topping up the tank techniques, or the provision has inadequate stress, fluid supply items could be selected to supply the barrier fluid to seal faces. These have the added advantages of being in a position to supply a water/glycol combination or oil to provide freeze safety in extremely cold climates.
Wide-ranging advantages The advantages of upgrading to modern sealing options and assist techniques had been felt by a coal mine in Poland using a slurry pump to supply coal mud at 9 bar (135 psi) to filter press. Flushed packing resulted in huge dilution of product, resulting in significantly increased filtration instances and prices. The pump was sealed with a double mechanical seal designed to fulfill the arduous requirements of the process.
The supporting seal tank system reduced leakage and product dilution to just about zero. Return on investment was swift and the financial savings long-term. The advantages in phrases of water conservation have been equally longlasting and the company’s status enhanced.
The mining industry should cope with a tricky and costly challenge in relation to sustaining rotating gear. But the planning, processing and disposal of flush water constitutes an operational and monetary burden which is entirely avoidable.
And when a company can remove water waste concurrently rising reliability and lowering long run operational prices, the choice to upgrade to trendy techniques should surely be an ethical imperative as properly as making sound business sense.
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