Water waste is commonly deemed an undesirable, however inevitable by-product of mining processes. Yet fashionable pump sealing know-how exists which can virtually eliminate this waste whereas conserving vitality, bettering pump reliability and attaining long run operational savings.
Water is one of the most significant, and more and more imperilled, sources on earth. That much is understood and acknowledged by industries throughout the globe.
However, it’s also one of the unnecessarily squandered sources in mining operations. And whereas เกจวัดแรงดันแบบแห้ง has begun to embrace effectivity and sustainability-led advances corresponding to automation and renewable power, it remains steadfastly set in its methods when it comes to slurry pump know-how.
Three approaches are routinely specified by pump producers to seal slurry pumps: mechanical packing, expellers (also generally recognized as ‘dynamic’ seals’) and single mechanical seals. All come with vital limitations, including poor reliability, decreased mean occasions between failure (MTBF), intensive upkeep necessities and higher operational costs.
These factors alone ought to give mine managers trigger for a re-evaluation of the sealing methods used on slurry pumps. However, any company with a dedication to the International Standards Organisation ISO-14001 Standard for environmental administration methods and ISO-50001 Standard for power management systems ought to pay consideration to the extreme water waste and high power consumption that outcomes from choosing these traditional 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 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 each single slurry seals and expellers require a supply of cool, clean flush water to be injected into the process at excessive pressure, sustaining a secure fluid film between the fragile seal faces to keep 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 the next stress than the stuffing field pressure, in line with the industry commonplace American Petroleum Institute (API) Piping Plan 32. Water which doesn’t leak onto the bottom or into the method is sent to the tailings dam. This additionally has an impact on the water balance of the plant.
This approach constitutes a loss of clean water amounting to billions of gallons a 12 months globally. One massive, typical slurry pump usually 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 in need of demand by some 40% by 20301 , removing unnecessary use of this useful useful resource ought to arguably be a central plank of any responsible sustainability programme. Yet extreme water use, and the upper power consumption it entails, remain embedded in the processes of many mining corporations. Worse nonetheless, it is truthful to say that it is typically accepted as simply ‘par for the course’ by reliability engineers and management alike.
But the very fact is that water waste on any scale is a completely unnecessary characteristic of slurry operations as it can be almost completely eliminated just by using superior double mechanical seals and fashionable water administration help methods.
Improve reliability The kind of seal selected, the environment during which it operates, and crucially, the tank support system which provides the water to maximise seal life, combine to supply the solution to excessive water waste and energy use.
Modern double mechanical seals have two units of faces, one sealing to the process fluid and one to ambiance, with a barrier area between the 2. They are designed to satisfy the arduous requirements of heavy duty slurry functions, with fortified metallic parts that are extremely proof against corrosion and erosion. Large ports and elevated radial clearances mean the lubrication which is vital to optimising seal life is maintained continuously 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 pressure higher than the product stress, making certain a consistent, stable and clear fluid movie 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 environment, allowing the cooler, denser water to sink again down to offer 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 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 systems, pressurised barrier tanks supply ratings as much as 435 psi (30 bar), making them ideal for these functions. Self-topping and self-pressurising, they’re additionally almost maintenance-free.
Where no plant water supply is out there for topping up the tank techniques, or the supply has inadequate strain, fluid supply items could be selected to provide the barrier fluid to seal faces. These have the added benefits of with the power to provide a water/glycol combination or oil to offer freeze protection in extremely chilly climates.
Wide-ranging benefits The advantages of upgrading to trendy sealing options and assist methods were felt by a coal mine in Poland utilizing a slurry pump to provide coal mud at 9 bar (135 psi) to filter press. Flushed packing resulted in huge dilution of product, leading to tremendously elevated filtration times 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 reduced leakage and product dilution to just about zero. Return on funding was swift and the savings long-term. The advantages when it comes to water conservation have been equally longlasting and the company’s reputation enhanced.
The mining business must take care of a tricky and costly problem when it comes to sustaining rotating gear. But the planning, processing and disposal of flush water constitutes an operational and financial burden which is entirely avoidable.
And when an organization can eliminate water waste concurrently increasing reliability and reducing long run operational prices, the decision to upgrade to trendy techniques should surely be an ethical imperative in addition to making sound business sense.