Water waste is often deemed an unwanted, but inevitable by-product of mining processes. Yet trendy pump sealing know-how exists which might nearly get rid of this waste while conserving energy, enhancing pump reliability and attaining long term operational financial savings.
Water is likely considered one of the most vital, and more and more imperilled, sources on earth. That a lot is understood and acknowledged by industries across the globe.
However, additionally it is one of the unnecessarily squandered assets in mining operations. And whereas the industry has begun to embrace efficiency and sustainability-led advances such as automation and renewable power, it remains steadfastly set in its ways in terms of slurry pump know-how.
Three approaches are routinely specified by pump producers to seal slurry pumps: mechanical packing, expellers (also generally known as ‘dynamic’ seals’) and single mechanical seals. All include vital limitations, together with poor reliability, reduced imply times between failure (MTBF), intensive maintenance necessities and higher operational costs.
These components alone ought to give mine managers trigger 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 administration systems ought to pay attention to the extreme water waste and high vitality consumption that outcomes from opting for these conventional sealing strategies.
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 elements 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, whereas both single slurry seals and expellers require a provide of cool, clean flush water to be injected into the process at excessive pressure, sustaining a secure fluid movie between the fragile seal faces to keep 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 the next pressure than the stuffing box strain, in line with the trade standard American Petroleum Institute (API) Piping Plan 32. Water which doesn’t leak onto the ground or into the process is distributed to the tailings dam. This additionally has an effect on the water stability of the plant.
This approach constitutes a lack of clear water amounting to billions of gallons a 12 months globally. One giant, conventional 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 stunning statistic by any measure.
At a time when global water provide is predicted to fall in want of demand by some 40% by 20301 , removing pointless use of this useful useful resource should arguably be a central plank of any accountable sustainability programme. Yet เกจ์วัดความดัน , and the higher energy consumption it entails, stay embedded within the processes of many mining corporations. Worse still, it’s fair to say that it is often 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 unnecessary function of slurry operations as it can be nearly totally eliminated simply by employing superior double mechanical seals and trendy water management support methods.
Improve reliability The type of seal chosen, the setting in which it operates, and crucially, the tank support system which supplies the water to maximise seal life, mix to supply the answer to extreme 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 2. They are designed to meet the arduous requirements of heavy duty slurry purposes, with fortified steel components that are highly proof against corrosion and erosion. Large ports and increased radial clearances imply the lubrication which is significant 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 course of which supplies clean, cool water to the barrier space between the double seals at a stress larger than the product pressure, guaranteeing a consistent, steady and clean fluid film to keep the seal faces cool and lubricated.
As the mechanical seals generate warmth, the recent water in the barrier house rises to the tank and is radiated to the ambiance, allowing the cooler, denser water to sink again down to provide cool lubrication to the seal faces. Most importantly, the flush water is consistently recycled, flowing across 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 set up special pump methods, pressurised barrier tanks provide ratings up to 435 psi (30 bar), making them ideal for these applications. Self-topping and self-pressurising, they are additionally nearly maintenance-free.
Where no plant water provide is out there for topping up the tank systems, or the provision has inadequate strain, fluid supply items could be selected to supply the barrier fluid to seal faces. These have the added benefits of with the flexibility to supply a water/glycol combination or oil to offer freeze protection in extremely chilly climates.
Wide-ranging benefits The advantages of upgrading to modern sealing solutions and assist 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, resulting in significantly increased filtration times 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 reduced leakage and product dilution to just about zero. Return on investment was swift and the savings long-term. The advantages in phrases of water conservation have been equally longlasting and the company’s reputation enhanced.
The mining trade should take care of a tricky and costly challenge in relation to sustaining rotating gear. But the planning, processing and disposal of flush water constitutes an operational and monetary burden which is totally avoidable.
And when an organization can get rid of water waste at the same time as growing reliability and reducing long run operational costs, the decision to improve to modern systems should surely be an ethical imperative in addition to making sound business sense.
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