Water waste is often deemed an unwanted, however inevitable by-product of mining processes. Yet trendy pump sealing technology exists which can virtually remove this waste whereas conserving vitality, enhancing pump reliability and achieving long term operational financial savings.
Water is one of the most significant, and increasingly 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 assets in mining operations. And whereas the business has begun to embrace effectivity and sustainability-led advances such as automation and renewable power, it stays steadfastly set in its methods when it comes to slurry pump know-how.
Three approaches are routinely specified by pump manufacturers to seal slurry pumps: mechanical packing, expellers (also generally recognized as ‘dynamic’ seals’) and single mechanical seals. All come with important limitations, including poor reliability, reduced imply instances between failure (MTBF), intensive maintenance necessities and higher operational prices.
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 administration methods and ISO-50001 Standard for vitality management methods ought to pay consideration to the extreme water waste and high power consumption that outcomes from opting for these traditional sealing strategies.
digital pressure gauge ราคา 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 clear 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 method at high pressure, maintaining a steady fluid movie between the fragile seal faces to maintain them cool and lubricated, whereas forcing the damaging slurry away.
The flush water required in all three sealing approaches is provided from an external source and injected into the method at a better stress than the stuffing field pressure, consistent with the business commonplace American Petroleum Institute (API) Piping Plan 32. Water which doesn’t leak onto the ground or into the process is sent 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 yr globally. One massive, conventional slurry pump typically consumes 10 US gallons (37.eight litres) per minute, amounting to five.2 million US gallons (19.6 million litres) of water yearly – a stunning statistic by any measure.
At a time when world water provide is predicted to fall wanting demand by some 40% by 20301 , eradicating unnecessary use of this valuable resource ought to arguably be a central plank of any accountable sustainability programme. Yet extreme water use, and the upper power consumption it entails, stay embedded within the processes of many mining companies. Worse nonetheless, it’s fair 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 feature of slurry operations as it can be almost completely eliminated just by employing advanced double mechanical seals and trendy water management support systems.
Improve reliability The kind of seal selected, the environment in which it operates, and crucially, the tank support system which provides the water to maximise seal life, combine to provide the solution 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 space between the two. They are designed to satisfy the arduous requirements of heavy obligation slurry purposes, with fortified metallic elements which are highly immune to corrosion and erosion. Large ports and elevated radial clearances mean the lubrication which is important to optimising seal life is maintained constantly 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 house between the double seals at a stress larger than the product strain, ensuring a consistent, steady and clean fluid film to keep the seal faces cool and lubricated.
As the mechanical seals generate heat, the new water in the barrier area rises to the tank and is radiated to the atmosphere, permitting 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 across the seal faces in a continuous loop and reducing leakage to the absolute minimum, roughly a teaspoonful a day.
While API Plan 32 is unsuitable for servicing multiple slurry pumps in a ‘series train’ without the necessity to install particular pump methods, pressurised barrier tanks offer ratings up to 435 psi (30 bar), making them best for these purposes. Self-topping and self-pressurising, they are also almost maintenance-free.
Where no plant water supply is available for topping up the tank techniques, or the availability has insufficient stress, fluid delivery items could be chosen to supply the barrier fluid to seal faces. These have the added benefits of being ready to supply a water/glycol mixture or oil to provide freeze safety in extremely chilly climates.
Wide-ranging benefits The advantages of upgrading to fashionable sealing options and help techniques had been felt by a coal mine in Poland utilizing 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 greatly elevated filtration occasions 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 nearly zero. Return on funding was swift and the financial savings long-term. The benefits in terms of water conservation have been equally longlasting and the company’s reputation enhanced.
The mining trade must 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 financial burden which is completely avoidable.
And when an organization can get rid of water waste at the same time as increasing reliability and lowering long run operational costs, the decision to upgrade to trendy systems should surely be a moral imperative in addition to making sound business sense.