Less waste means more reliability

Water waste is commonly deemed an unwanted, however inevitable by-product of mining processes. Yet trendy pump sealing know-how exists which can virtually remove this waste whereas conserving power, bettering pump reliability and attaining long term operational financial savings.
Water is among the most vital, and increasingly imperilled, sources on earth. That a lot is understood and acknowledged by industries across the globe.
However, it is also some of the unnecessarily squandered sources in mining operations. And while the industry has begun to embrace effectivity and sustainability-led advances such as automation and renewable energy, it remains steadfastly set in its methods in terms of slurry pump technology.
Three approaches are routinely specified by pump manufacturers to seal slurry pumps: mechanical packing, expellers (also known as ‘dynamic’ seals’) and single mechanical seals. All include significant limitations, including poor reliability, decreased imply times between failure (MTBF), intensive maintenance requirements and better operational prices.
These components alone should give mine managers trigger for a re-evaluation of the sealing methods 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 power management systems should take observe of the extreme water waste and high power consumption that outcomes 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 features of slurry processing which is seal flush water injection.
On gland packed pumps it’s essential that packing is flushed with clear water to keep it cool and lubricated, while both single slurry seals and expellers require a supply of cool, clean flush water to be injected into the process at high stress, maintaining a stable fluid film between the delicate seal faces to keep them cool and lubricated, while 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 strain than the stuffing box stress, according to the industry normal 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 steadiness of the plant.
This method constitutes a loss of clear water amounting to billions of gallons a year globally. One massive, standard slurry pump sometimes consumes 10 US gallons (37.eight litres) per minute, amounting to five.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 wanting demand by some 40% by 20301 , eradicating unnecessary use of this useful resource ought to arguably be a central plank of any responsible sustainability programme. Yet excessive water use, and the upper energy consumption it entails, stay embedded within the processes of many mining firms. Worse nonetheless, it is honest to say that it is typically accepted as merely ‘par for the course’ by reliability engineers and administration alike.
But the fact is that water waste on any scale is a completely pointless feature of slurry operations as it can be almost completely eliminated simply by using superior double mechanical seals and fashionable water management support methods.
Improve reliability The type of seal chosen, the environment during which it operates, and crucially, the tank help system which provides the water to maximise seal life, mix to supply the solution to extreme water waste and power use.
Modern double mechanical seals have two units of faces, one sealing to the process fluid and one to environment, with a barrier area between the two. They are designed to meet the arduous necessities of heavy responsibility slurry functions, with fortified metal elements which are highly immune 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 solution. It employs a thermosiphon course of which supplies clear, cool water to the barrier area between the double seals at a strain greater than the product strain, making certain a constant, secure and clean fluid film to maintain the seal faces cool and lubricated.
As the mechanical seals generate heat, the recent water in the barrier space rises to the tank and is radiated to the atmosphere, permitting the cooler, denser water to sink back down to supply cool lubrication to the seal faces. เกจวัดแรงดันภาษาอังกฤษ , the flush water is constantly recycled, flowing throughout the seal faces in a continuous loop and lowering leakage to absolutely the 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 special pump methods, pressurised barrier tanks supply scores as much as 435 psi (30 bar), making them perfect for these functions. Self-topping and self-pressurising, they are additionally nearly maintenance-free.
Where no plant water supply is on the market for topping up the tank methods, or the supply has insufficient pressure, fluid delivery items can be selected to supply 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 extremely cold climates.
Wide-ranging benefits The advantages of upgrading to modern sealing options and support methods have been 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, leading to tremendously elevated filtration instances and costs. The pump was sealed with a double mechanical seal designed to meet the arduous necessities of the method.
The supporting seal tank system lowered leakage and product dilution to virtually zero. Return on funding was swift and the savings long-term. The advantages by means of water conservation have been equally longlasting and the company’s popularity enhanced.
The mining business should cope with a tricky and costly problem in relation to maintaining rotating tools. But the planning, processing and disposal of flush water constitutes an operational and financial burden which is entirely avoidable.
And when a company can remove water waste at the same time as growing reliability and decreasing long run operational costs, the choice to improve to modern methods should surely be an ethical crucial in addition to making sound business sense.
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