Less waste means extra reliability

Water waste is commonly deemed an unwanted, however inevitable by-product of mining processes. Yet modern pump sealing know-how exists which can just about eliminate this waste whereas conserving power, bettering pump reliability and reaching long run operational savings.
Water is likely considered one of the most vital, and increasingly imperilled, assets on earth. That a lot is known and acknowledged by industries throughout the globe.
However, additionally it is one of the most unnecessarily squandered assets in mining operations. And whereas the industry has begun to embrace efficiency and sustainability-led advances such as automation and renewable vitality, it stays steadfastly set in its ways in phrases 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 come with significant limitations, including poor reliability, decreased imply times between failure (MTBF), intensive upkeep requirements and better operational costs.
These elements alone ought to give mine managers cause for a re-evaluation of the sealing methods used on slurry pumps. However, any company with a commitment to the International Standards Organisation ISO-14001 Standard for environmental administration techniques and ISO-50001 Standard for energy administration techniques ought to take observe of the excessive water waste and excessive energy 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 wasteful aspects of slurry processing which is seal flush water injection.
On gland packed pumps it’s essential that packing is flushed with clear water to maintain it cool and lubricated, whereas both single slurry seals and expellers require a provide of cool, clear flush water to be injected into the method at excessive strain, sustaining a steady fluid movie 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 supplied from an exterior supply and injected into the method at a higher strain than the stuffing field pressure, in line with the trade 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 method constitutes a loss of clear water amounting to billions of gallons a year globally. One large, typical slurry pump typically consumes 10 US gallons (37.eight litres) per minute, amounting to 5.2 million US gallons (19.6 million litres) of water every year – a shocking statistic by any measure.
At a time when international water supply is predicted to fall short of demand by some 40% by 20301 , eradicating unnecessary use of this priceless resource should arguably be a central plank of any accountable sustainability programme. Yet excessive water use, and the higher energy consumption it entails, stay embedded in the processes of many mining firms. Worse nonetheless, it is honest to say that it is usually accepted as simply ‘par for the course’ by reliability engineers and administration alike.
But the very fact is that water waste on any scale is a completely unnecessary characteristic of slurry operations as it might be nearly totally eradicated simply by using superior double mechanical seals and trendy water management assist techniques.
Improve reliability The type of seal selected, the environment by which it operates, and crucially, the tank support system which provides the water to maximise seal life, mix to supply 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 environment, with a barrier space between the 2. They are designed to meet the arduous necessities of heavy obligation slurry applications, with fortified metal components which are extremely immune to corrosion and erosion. Large ports and increased radial clearances mean the lubrication which is vital 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 provides clean, cool water to the barrier house between the double seals at a pressure greater than the product pressure, guaranteeing a consistent, steady and clear fluid film to keep the seal faces cool and lubricated.
As the mechanical seals generate heat, the hot water in the barrier house rises to the tank and is radiated to the ambiance, 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 across the seal faces in a steady 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’ with out the want to install particular pump methods, pressurised barrier tanks offer rankings up to 435 psi (30 bar), making them best for these purposes. Self-topping and self-pressurising, they’re also almost maintenance-free.
Where no plant water provide is on the market for topping up the tank systems, or the availability has inadequate strain, fluid supply models may be chosen to provide the barrier fluid to seal faces. These have the added advantages of with the flexibility to supply a water/glycol combination or oil to provide freeze safety in extraordinarily chilly climates.
Wide-ranging advantages The advantages of upgrading to modern sealing solutions and assist systems had 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 greatly elevated filtration occasions and costs. The pump was sealed with a double mechanical seal designed to satisfy the arduous requirements of the method.
เกจวัดแรงดันต่ำ supporting seal tank system reduced leakage and product dilution to just about zero. Return on pressure gauge ด้าน ดูด was swift and the financial savings long-term. The advantages when it comes to water conservation have been equally longlasting and the company’s reputation enhanced.
The mining industry should cope with a tricky and dear challenge in relation to maintaining rotating equipment. But the planning, processing and disposal of flush water constitutes an operational and monetary burden which is entirely avoidable.
And when an organization can eliminate water waste concurrently increasing reliability and reducing long term operational costs, the choice to improve to fashionable systems should surely be a moral imperative as nicely as making sound business sense.
Share

Leave a Comment