Water waste is commonly deemed an undesirable, but inevitable by-product of mining processes. Yet fashionable pump sealing technology exists which may nearly get rid of this waste while conserving power, improving pump reliability and attaining long run operational financial savings.
Water is one of the most important, and more and more imperilled, assets on earth. That much is known and acknowledged by industries across the globe.
However, it is also some of the unnecessarily squandered assets in mining operations. And whereas the industry has begun to embrace efficiency and sustainability-led advances corresponding to automation and renewable vitality, it remains steadfastly set in its ways when it comes to slurry pump expertise.
pressure gauge ไฮ ด รอ ลิ ค are routinely specified by pump producers to seal slurry pumps: mechanical packing, expellers (also generally known as ‘dynamic’ seals’) and single mechanical seals. All come with significant limitations, together with poor reliability, reduced mean instances between failure (MTBF), intensive upkeep requirements and better operational prices.
These elements 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 management techniques ought to take notice of the extreme water waste and high vitality consumption that results from choosing 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 clean 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 method at high strain, maintaining a steady 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 provided from an exterior supply and injected into the method at a better strain than the stuffing field stress, in line with the business commonplace American Petroleum Institute (API) Piping Plan 32. Water which doesn’t leak onto the ground or into the method is sent to the tailings dam. This additionally has an impact on the water stability of the plant.
This strategy constitutes a loss of clear water amounting to billions of gallons a 12 months globally. One giant, typical 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 global water provide is predicted to fall short of demand by some 40% by 20301 , removing unnecessary use of this valuable 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 in the processes of many mining firms. Worse nonetheless, it’s fair to say that it is often accepted as simply ‘par for the course’ by reliability engineers and administration alike.
But the actual fact is that water waste on any scale is a totally unnecessary characteristic of slurry operations as it could be virtually completely eliminated simply by employing superior double mechanical seals and modern water administration support techniques.
Improve reliability The type of seal selected, the surroundings during which it operates, and crucially, the tank assist system which provides the water to maximise seal life, combine to offer the answer to extreme water waste and energy use.
Modern double mechanical seals have two units of faces, one sealing to the process fluid and one to environment, with a barrier house between the 2. They are designed to meet the arduous necessities of heavy responsibility slurry functions, with fortified metallic parts which are extremely immune to corrosion and erosion. Large ports and elevated radial clearances mean the lubrication which is significant to optimising seal life is maintained continuously and persistently.
A pressurised barrier tank system is central to the environmental sustainability of this resolution. It employs a thermosiphon process which supplies clear, cool water to the barrier space between the double seals at a stress greater than the product stress, guaranteeing a constant, steady and clean fluid movie to maintain the seal faces cool and lubricated.
As the mechanical seals generate warmth, the recent water in the barrier space rises to the tank and is radiated to the environment, allowing 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 across the seal faces in a continuous loop and lowering leakage to the absolute minimal, 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 provide ratings up to 435 psi (30 bar), making them perfect for these applications. Self-topping and self-pressurising, they are additionally virtually maintenance-free.
Where no plant water provide is out there for topping up the tank methods, or the availability has insufficient strain, fluid supply models may be chosen to supply the barrier fluid to seal faces. These have the added advantages of being ready to supply a water/glycol mixture or oil to supply freeze protection in extremely chilly climates.
Wide-ranging benefits The advantages of upgrading to fashionable sealing solutions and support techniques had been felt by a coal mine in Poland utilizing a slurry pump to produce coal mud at 9 bar (135 psi) to filter press. Flushed packing resulted in huge dilution of product, leading to tremendously elevated 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 reduced 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 status enhanced.
The mining industry should cope with a tricky and expensive challenge in terms 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 an organization can remove water waste concurrently rising reliability and reducing long run operational prices, the decision to improve to modern systems ought to certainly be an ethical imperative as nicely as making sound business sense.