Water waste is commonly deemed an undesirable, however inevitable by-product of mining processes. Yet modern pump sealing expertise exists which can just about get rid of this waste while conserving power, bettering pump reliability and reaching long run operational savings.
Water is likely considered one of the most important, and increasingly imperilled, sources on earth. That much is known and acknowledged by industries across the globe.
However, it’s also one of the most unnecessarily squandered resources in mining operations. And whereas the trade has begun to embrace effectivity and sustainability-led advances such as automation and renewable power, it stays steadfastly set in its ways in phrases of slurry pump technology.
Three approaches are routinely specified by pump manufacturers to seal slurry pumps: mechanical packing, expellers (also generally identified as ‘dynamic’ seals’) and single mechanical seals. All come with significant limitations, including poor reliability, decreased imply times between failure (MTBF), intensive maintenance requirements and higher operational costs.
These components alone ought to give mine managers cause for a re-evaluation of the sealing strategies used on slurry pumps. However, any firm with a dedication to the International Standards Organisation ISO-14001 Standard for environmental administration systems and ISO-50001 Standard for energy administration methods ought to pay attention to the excessive water waste and excessive power consumption that outcomes 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 some of the wasteful aspects of slurry processing which is seal flush water injection.
On เกจวัดแรงดันเบนซิน packed pumps it’s important that packing is flushed with clean water to maintain it cool and lubricated, whereas each single slurry seals and expellers require a provide of cool, clean flush water to be injected into the process at excessive strain, 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 exterior supply and injected into the process at a better pressure than the stuffing box stress, according to the business 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 additionally has an effect on the water steadiness of the plant.
This approach constitutes a loss of clear water amounting to billions of gallons a 12 months globally. One giant, standard 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 yearly – a surprising statistic by any measure.
At a time when global water supply is predicted to fall short of demand by some 40% by 20301 , eradicating pointless use of this priceless resource ought to arguably be a central plank of any accountable sustainability programme. Yet extreme water use, and the higher power consumption it entails, remain embedded within the processes of many mining firms. Worse nonetheless, it is truthful to say that it is usually accepted as simply ‘par for the course’ by reliability engineers and management alike.
But the precise fact is that water waste on any scale is a very unnecessary characteristic of slurry operations as it might be almost completely eradicated just by employing advanced double mechanical seals and fashionable water management assist systems.
Improve reliability The sort of seal chosen, the setting during which it operates, and crucially, the tank help system which supplies the water to maximise seal life, mix to offer the solution to excessive water waste and energy use.
Modern double mechanical seals have two sets of faces, one sealing to the method fluid and one to ambiance, with a barrier space between the 2. They are designed to satisfy the arduous requirements of heavy duty slurry functions, with fortified metallic parts that are extremely immune to corrosion and erosion. Large ports and elevated radial clearances imply the lubrication which is important to optimising seal life is maintained constantly and consistently.
A pressurised barrier tank system is central to the environmental sustainability of this solution. It employs a thermosiphon course of which supplies clear, cool water to the barrier house between the double seals at a stress greater than the product stress, guaranteeing a consistent, steady and clear fluid film to keep the seal faces cool and lubricated.
As the mechanical seals generate heat, the recent 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 supply 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 need to set up particular pump systems, pressurised barrier tanks provide ratings up to 435 psi (30 bar), making them ideal for these purposes. Self-topping and self-pressurising, they are additionally nearly maintenance-free.
Where no plant water provide is on the market for topping up the tank methods, or the availability has insufficient strain, fluid delivery models can be selected to supply the barrier fluid to seal faces. These have the added benefits of having the power to provide a water/glycol mixture or oil to supply freeze safety in extremely cold climates.
Wide-ranging advantages The benefits of upgrading to modern sealing solutions and help techniques have 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 large dilution of product, resulting in tremendously increased filtration occasions 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 funding was swift and the financial savings long-term. The benefits when it comes to water conservation have been equally longlasting and the company’s reputation enhanced.
The mining trade should cope with a tricky and expensive problem when it comes to sustaining rotating tools. But the planning, processing and disposal of flush water constitutes an operational and monetary burden which is completely avoidable.
And when an organization can eliminate water waste at the same time as rising reliability and lowering long term operational costs, the choice to improve to modern systems should absolutely be an ethical imperative in addition to making sound enterprise sense.
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