Water waste is commonly deemed an unwanted, but inevitable by-product of mining processes. Yet trendy pump sealing technology exists which can just about get rid of this waste while conserving power, improving pump reliability and reaching long term operational financial savings.
Water is likely considered one of the most significant, and more and more imperilled, sources on earth. That a lot is known and acknowledged by industries throughout the globe.
However, additionally it is one of the most unnecessarily squandered resources in mining operations. And while the business has begun to embrace effectivity and sustainability-led advances corresponding to automation and renewable energy, it remains steadfastly set in its methods in phrases of slurry pump expertise.
Three approaches are routinely specified by pump producers to seal slurry pumps: mechanical packing, expellers (also known as ‘dynamic’ seals’) and single mechanical seals. All come with important limitations, including poor reliability, lowered imply instances between failure (MTBF), intensive upkeep requirements and better operational costs.
These factors alone should give mine managers cause for a re-evaluation of the sealing methods 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 administration methods ought to take note of the excessive water waste and excessive vitality consumption that outcomes from opting for these traditional 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 elements of slurry processing which is seal flush water injection.
On gland packed pumps it’s important that packing is flushed with clear water to keep it cool and lubricated, whereas both single slurry seals and expellers require a supply of cool, clean flush water to be injected into the process at high pressure, maintaining a stable fluid movie 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 equipped from an exterior source and injected into the process at a better strain than the stuffing box strain, according to the industry commonplace 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 also has an effect on the water steadiness of the plant.
This approach constitutes a lack of clean water amounting to billions of gallons a 12 months globally. One large, 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 yearly – a shocking statistic by any measure.
At a time when world water provide is predicted to fall in want of demand by some 40% by 20301 , removing unnecessary use of this useful useful resource ought to arguably be a central plank of any accountable sustainability programme. Yet ราคาเพรสเชอร์เกจ , and the higher energy consumption it entails, remain embedded in the processes of many mining corporations. Worse still, it is truthful to say that it’s often accepted as merely ‘par for the course’ by reliability engineers and administration alike.
But the precise fact is that water waste on any scale is a completely unnecessary characteristic of slurry operations as it can be nearly totally eliminated just by employing superior double mechanical seals and fashionable water administration support methods.
Improve reliability The sort of seal selected, the environment during which it operates, and crucially, the tank assist system which supplies the water to maximise seal life, combine to supply the answer to excessive 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 house between the 2. They are designed to fulfill the arduous necessities of heavy duty slurry functions, with fortified metallic components that are extremely proof against corrosion and erosion. Large ports and elevated radial clearances imply 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 resolution. It employs a thermosiphon process which provides clean, cool water to the barrier space between the double seals at a pressure larger 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 space rises to the tank and is radiated to the ambiance, 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 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’ with out the want to install particular pump techniques, pressurised barrier tanks offer ratings up to 435 psi (30 bar), making them ideal for these purposes. Self-topping and self-pressurising, they are additionally almost maintenance-free.
Where no plant water supply is on the market for topping up the tank methods, or the supply has insufficient stress, fluid supply models may be chosen to produce the barrier fluid to seal faces. These have the added advantages of having the ability to supply a water/glycol mixture or oil to offer freeze protection in extraordinarily chilly climates.
Wide-ranging advantages The benefits of upgrading to modern sealing options and support techniques were 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 large dilution of product, resulting in tremendously increased filtration occasions and prices. The pump was sealed with a double mechanical seal designed to satisfy the arduous necessities of the method.
The supporting seal tank system decreased leakage and product dilution to just about zero. Return on investment was swift and the financial savings long-term. The benefits when it comes to water conservation have been equally longlasting and the company’s status enhanced.
The mining industry must cope with a tricky and dear problem in relation to sustaining rotating tools. But the planning, processing and disposal of flush water constitutes an operational and monetary burden which is entirely avoidable.
And when an organization can remove water waste at the identical time as growing reliability and lowering long run operational costs, the decision to upgrade to trendy techniques ought to surely be a moral crucial as nicely as making sound enterprise sense.
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