บทความ เกจวัดแรงดัน

Weir’s resolution for froth challenges

Froth pumping remains some of the advanced engineering challenges in mineral processing. Here, เพรสเชอร์เกจ provides recommendation for coping with the key challenges in this operation, the method to maximise pump availability and minimise maintenance in operators’ flotation circuits.
To counteract declining digital pressure gauge , increasingly mine operators are investing in methods to extend the minerals reclaimed from froth pumping. However, when these techniques are deployed with out making allowances for the design of the mine’s froth pumping gear, it may end up in the lack of useful minerals and profits.
Froth pumping stays one of the most advanced engineering challenges in mineral processing. This is basically due to the reality that air administration issues in the hopper, sump and pump itself can sometimes result in inefficient pumping, increased upkeep and even lost product.
“We’ve began to note a sample among our prospects who are having trouble with their froth pumps,” stated Les Harvey, regional product manager for Slurry Pumps at Weir Minerals. “By using extra flocculants and different chemicals designed to enhance mineral restoration, they’re exacerbating present problems in circuit design and decreasing the returns they’re on the lookout for.”

Close examination of the froth’s make-up and bodily qualities is commonly wanted to resolve points. Ensuring operators’ froth handling tools adheres to best design practices is an important first step in resolving issues.
Maintaining stress The key problem in froth pumping is coping with air in the pump itself, as it tends to naturally centrifuge into the impeller’s eye, the place it builds up into an “air lock” which impedes the movement of slurry through the pump.
In addition to decreasing the pump’s efficiency, the air build-up in the pump will reduce its circulate and improve the slurry level within the suction hopper. The elevated slurry stage could push the pocket of air via the pump, causing surging and excessive vibration which may harm the pump bearings, impeller and shaft. “The finest method to manage air in a froth pump is to spend cash on a froth pump with a steady air elimination system (CARS), which we’ve in our Warman AHF, MF and LF pumps,” says Harvey.
This system permits air to maneuver from the pump’s impeller eye to an air assortment chamber in the back by way of a vent hole within the impeller. From the chamber, a circulate inducer removes the air from the pump via a vent pipe. “It’s also necessary to position the pump’s discharge pipe on the prime of the pump, or at a 45° angle as this will give air trapped on the top of the casing a method to escape the pump.”

Solving issues “A persistent drawback we see is when hoppers designed to fulfill the calls for of slurry pumping are used in a froth pumping application. Slurry hoppers require turbulence to stop the mineral content from settling, while turbulence in a froth pump prevents the air from escaping and results in blockages,” stated Harvey.
Tanks designed for froth pumping promote steady round motion, where solids and liquids are despatched to the outside of the sump for additional transport whereas air centrifuges into the centre the place it might be eliminated. This ‘whirlpool’ movement may be encouraged by introducing the slurry from the highest of the tank at a tangential angle. Conical designs, rather than those with a flat or rounded flooring, additional improve the move of minerals and froth into the pump.
Smooth crusing To forestall blockages, the consumption pipe which hyperlinks the tank to the pump ought to have a big diameter and slope downwards towards the pump. This design permits escaped air to separate and journey again up the pipe the place it might possibly escape from the sump, quite than building up into blockages.
“The shorter your intake pipe, the harder it’s for blockages to construct up. However, along with a upkeep spool and isolation valve, it’s a good idea to depart sufficient area for a water injection port, which is helpful for flushing out any solids build up,” mentioned Harvey.
“To make maintenance simpler, a dump valve could be included on the suction aspect of the pump, between the pump and the isolation valve. This will permit users to drain slurry from the pump and the discharge pipe system when stopping the pump for maintenance.”

Tenacious froths Froths are sometimes categorised as both brittle, with massive air bubbles that break simply, or tenacious, the place air varieties tight bubbles around minerals and is difficult to separate. Froth being extra tenacious than was accounted for is a frequent cause of blockages as air cannot effectively be removed.
“Two things are taking place available within the market today. On one hand, mine operators are grinding the product much finer than before to liberate extra from the waste rock. They’re also using flocculants that produce much smaller bubbles which lock up the air much more than brittle froths,” said Harvey. “We’re working along with customers to find ways to manage these extra tenacious froths, by looking at their circuit design and dealing with areas the place the air might accumulate and block the system, paying particular attention to their pumps, pipes and sumps.