Water waste is commonly deemed an unwanted, however inevitable by-product of mining processes. Yet modern pump sealing expertise exists which may nearly remove this waste while conserving power, improving pump reliability and attaining long term operational financial savings.
Water is one of the most significant, and increasingly imperilled, sources on earth. That much is understood and acknowledged by industries throughout the globe.
However, additionally it is one of the unnecessarily squandered resources in mining operations. And whereas the industry has begun to embrace effectivity and sustainability-led advances similar to automation and renewable energy, it stays steadfastly set in its methods when it comes to slurry pump expertise.
Three approaches are routinely specified by pump manufacturers to seal slurry pumps: mechanical packing, expellers (also often recognized as ‘dynamic’ seals’) and single mechanical seals. All include important limitations, together with poor reliability, decreased imply instances between failure (MTBF), intensive maintenance necessities and higher operational prices.
These elements alone should give mine managers cause for a re-evaluation of the sealing methods used on slurry pumps. However, any company with a commitment to the International Standards Organisation ISO-14001 Standard for environmental management methods and ISO-50001 Standard for vitality management methods should take observe of the excessive water waste and excessive energy consumption that outcomes from opting for these traditional sealing methods.
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 aspects of slurry processing which is seal flush water injection.
On gland packed pumps it’s important that packing is flushed with clear water to maintain 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 excessive stress, 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 supplied from an external source and injected into the method at a higher strain than the stuffing box strain, according to the trade commonplace American Petroleum Institute (API) Piping Plan 32. Water which doesn’t leak onto the ground or into the method is distributed to the tailings dam. This also has an impact on the water balance of the plant.
This method constitutes a lack of clear water amounting to billions of gallons a yr globally. One large, typical slurry pump usually consumes 10 US gallons (37.8 litres) per minute, amounting to five.2 million US gallons (19.6 million litres) of water every year – a shocking statistic by any measure.
At a time when international water supply is predicted to fall in want of demand by some 40% by 20301 , eradicating pointless use of this priceless useful resource should arguably be a central plank of any accountable sustainability programme. Yet excessive water use, and the upper power consumption it entails, stay embedded within the processes of many mining corporations. Worse still, it’s truthful to say that it is usually accepted as merely ‘par for the course’ by reliability engineers and management alike.
But the fact is that water waste on any scale is a totally pointless function of slurry operations as it can be nearly totally eliminated simply by using advanced double mechanical seals and modern water management assist systems.
Improve reliability The sort of seal selected, the environment during which it operates, and crucially, the tank support system which provides the water to maximise seal life, combine to offer 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 ambiance, with a barrier space between the two. They are designed to fulfill the arduous necessities of heavy responsibility slurry applications, with fortified steel parts that are highly resistant to corrosion and erosion. Large ports and elevated radial clearances imply the lubrication which is significant to optimising seal life is maintained continually and constantly.
A pressurised barrier tank system is central to the environmental sustainability of this resolution. It employs a thermosiphon course of which supplies clear, cool water to the barrier space between the double seals at a stress larger than the product stress, guaranteeing a constant, stable and clean fluid film to maintain 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 back down to supply cool lubrication to the seal faces. Most importantly, the flush water is constantly recycled, flowing across the seal faces in a steady loop and reducing leakage to the absolute 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 necessity to set up particular pump techniques, pressurised barrier tanks provide scores up to 435 psi (30 bar), making them best for these purposes. Self-topping and self-pressurising, they’re additionally almost maintenance-free.
Where เกจวัดแรงดันน้ําไทวัสดุ provide is out there for topping up the tank techniques, or the provision has inadequate pressure, fluid delivery units may be chosen to provide the barrier fluid to seal faces. These have the added benefits of being in a position to provide a water/glycol combination or oil to provide freeze protection in extraordinarily chilly climates.
Wide-ranging benefits The advantages of upgrading to trendy sealing solutions 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 big dilution of product, resulting in tremendously elevated filtration times 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 lowered leakage and product dilution to virtually zero. Return on investment was swift and the savings long-term. The benefits when it comes to water conservation have been equally longlasting and the company’s status enhanced.
The mining business should deal with a tricky and costly problem in phrases of sustaining rotating gear. But the planning, processing and disposal of flush water constitutes an operational and financial burden which is completely avoidable.
And when a company can get rid of water waste simultaneously growing reliability and decreasing long term operational costs, the choice to improve to fashionable systems should surely be an ethical crucial in addition to making sound enterprise sense.
Share