When processing highly abrasive bulk goods, the selection of suitable materials and the monitoring of operating conditions play a decisive role in minimizing the effects of wear. That's why we've dedicated a two-part series to this topic.
In the first article, we addressed mechanical and chemical wear, presenting corresponding countermeasures.
In this second part, you will find out how plant operators can protect their machines from:
- thermal and
- adhesive wear.
Furthermore, we will shed light on additional important measures that also serve as points of consideration.
The recycling of aluminum scrap is an important contribution to the circular economy. In this process, the secondary raw material is fed into a melting furnace using a charging feeder, making it available for reuse once again. Due to its proximity to the melting furnace and the associated consistently high heat exposure, the feeder is constantly subjected to thermal stress. Therefore, the discharge section of this feeder has been designed and manufactured as a bolted component. This allows for straightforward replacement in case of wear, as otherwise, the entire feeder would have to be repaired or replaced.
High temperature differences cause metals to expand. A meter of mild steel expands by around 1.2 mm when the temperature increases by 100°C. When designing a vibrating feeder for the transportation of hot material such as used foundry sand (approx. 300°C), this fact must be taken into particular consideration in order to prevent wear and breakage of the feeder. Hot material troughs divided into sections, which form a double bottom with the substructure, have proven their worth here. The troughs are fastened to the substructure with special plate springs and load washers to ensure expansion without wear and breakage.
The choice of bearing and lubrication is particularly important for large circular vibrating screens with an unbalanced shaft drive. On the one hand, an acceleration of up to 6g is aimed for process-related reasons and, on the other hand, the bearing lifespan should be kept at a high level. IFE relies on special oil bath lubrication to enable these two key aspects and at the same time ensure long lubrication intervals of up to 1 000 hours.
An example: In the case of an 3x7 m IFE waste screen (with a screening area of 21 m²), a nominal bearing service life (Lh10) of 13 000 hours is achieved with set vibration parameters and an acceleration of 4.8g!
Crushing limestone in the range of 0 to 1 200 mm is inherently a demanding task. To minimize wear on the crushers designed for this purpose, pre-separators are used to ensure that the shredders only process coarse material. An IFE vibrating grizzly fulfils this task optimally. The heavy-duty design of the wedge-shaped grate made of Hardox enables blockage-free screening at approx. 200 mm. This not only effectively safeguards the IFE screen itself from excessive wear but also significantly relieves the crushers, thus reducing overall wear and tear.
In the steel plant, there was a risk that tramp iron contained in the material flow could damage the machines used later in the process.
Additionally, the production lines had to be stopped completely and the iron bits had to be removed by hand, which was a lot of extra work. Smooth ore treatment was therefore not guaranteed.
This situation was finally resolved with the implementation of an electromagnetic overband separator from IFE.
When conveying and dosing bulk materials, it is crucial to control the material flow precisely. Through the selection and clever combination of suitable equipment, not only a smooth flow is achieved, but wear is also minimized. A tangible illustration of this concept is evident in the utilization of a feeder-chute combination.
For instance, an electromagnetic IFE vibrating feeder enables the dosing of alloy materials in the range of 10 – 120 mm. The associated IFE transfer chute ensures controlled transportation between the hopper and the transfer point. Together with the wear lining, it preserves the feeder floor in the inlet area. A flange with needle slide gate on the material hopper, a slide gate for adjusting the layer height and pneumatically operated flaps ensure precise dosing.
Their use is particularly recommended for conveying materials that only contain small amounts of tramp iron. The interfering tramp iron is removed from the material flow at an early stage to prevent premature wear and possible damage to the equipment. The simplest solution for this involves the use of permanent magnetic plates.
If this task also needs to be performed dust-free, IFE offers tubular magnetic chutes. Multiple magnetic plates can be arranged in the form of blocks. The occasional removal of tramp iron is easily accomplished by swinging out the individual magnetic blocks.
The outlined measures significantly contribute to reducing wear in material handling solutions. They not only extend the overall lifespan of the machines but also lead to more efficient utilization and reduced maintenance requirements. Through our comprehensive expertise and years of experience, we ensure the precise selection and successful implementation of the necessary steps.
BUT THAT'S NOT ALL!
Discover how IFE machines can be effectively protected against mechanical and chemical wear in the first part of the series.