Overband Magnetic Separator Selection Guide
Keywords: Permanent Overband Magnet, Electro Overband Magnetic Separator, Overband Magnetic Separator, Ferrite Cross Belt Magnet, Rare Earth Cross Belt Magnet
Overband magnet aka cross belt magnet is the most commonly type of conveyor belt magnetic separator. It generally uses a positioned permanent magnet or electromagnet as the magnetic source, and equipped with a simple self discharging device composed of two pulleys, belt, frame and motor.
Such a simple structure and working principle make it an essential and important role in some industries. For example: mining, recycling industry, aggregate industry, chemical industry and even food industry.
Before starting to read this guide, please understand which models of GTEK MAGNET® overband magnetic separator correspond to the following codes, because in the following articles we may use abbreviations to refer to the full names of these models:
For example:
- RCDF-10, represents electromagnetic oil-cooling type overband magnetic separator, adapted for 1000mm belt width;
- RCYQ-8, represents light-weight type permanent overband magnetic separator, adapted for 800mm belt width;
It's easy, right? Seems that you have learned our naming rules, now let us solve the problem that puzzles you.
Common Questions About GTEK® Overband Magnetic Separator
Faced with these so many overband magnet models, will you be confused?
- Should I choose manual unloading type or automatic type?
- Which magnetic intensity should I choose?
- Should I use an electromagnetic or permanent magnet overband magnet?
- For permanent magnet type overband magnet, should I choose ferrite(ceramic) or rare earth type?
- ......
If one of these problems has bothered you, then please read this article carefully, it will definitely help you in selecting the model of overband magnet. Of course, you can also directly contact our experts to help you choose the suitable model.
Manual Unloading or Automatic Unloading Overband Magnet
When choosing a suitable cross belt magnetic separator, you should first consider whether to use a manual unloading type or an automatic unloading type.
The basis for judging which to use is very simple: when the material contains less iron, choose the manual iron unloading type (RCYB, RCYP, RCDA, RCDB, RCDE) to save costs. When use manual unloading suspension magnet, it should be cleaned regularly according to the situation to ensure the proper operation of it.
When the material contains a lot of iron, you should choose an automatic discharging electromagnetic or permanent overband magnetic separator (RCYD, RCYQ, RCYK, RCDD, RCDF, RCDFJ) to ensure efficient iron removal and make the entire process highly automated.
Magnetic Intensity of Overband Magnetic Separator
The operation of overband magnet has the following characteristics:
- It is easier to absorb the long and large ones than the small and short ones;
- It is easier to absorb the flat ones than the balls;
- It is easier to absorb dynamic ones than static ones;
GTEK MAGNET® provides overband magnetic separators with a standard field strength of 700Gs (measured at the rated suspension height, on the surface of the conveyor belt), which is suitable for most iron removal conditions, and can easily suck up tramp iron of 0.1~15kg.
However, there are still some situations where need to use our magnetic enhanced version cross belt magnet, for example:
- When there is a high requirement for fine iron removal, it will be better to use the magnetic enhanced type (Better use with magnetic head pulley);
- If a multi-stage iron separating process is used, the magnetic field strength of the subsequent stage should also be higher;
- When the material is weak magnetic material, such as mild steel, a higher magnetic field strength is required to ensure the separation effect.
We provide 3 optional enhanced magnetic field strengths for permanent magnet and ordinary electromagnetic overband magnetic separator: 900Gs, 1200Gs, 1500Gs.
And for forced oil-cooling electromagnetic overband magnet, we are able to provide higher magnetic field options: 1750Gs, 2000Gs, 2250Gs and 2500Gs. If you need these enhanced models, please contact us.
Electro or Permanent Overband Magnetic Separator
When choosing electromagnetic or permanent magnetic overband magnet, we should consider the following points:
1. Material thickness: Electro overband magnet has a deeper penetrating magnetic field, which means it can be used to separate the tramp iron covered at the bottom in a thicker material layer. However, permanent overband magnetic separator has a shallower magnetic penetration depth and is suitable for thinner material layer, or used with magnetic pulley to achieve the effect of thicker layer separation.
2. Dimension and weight: From the appearance point of view, compare the permanent magnet type with electromagnetic type adapted for the same width belt conveyor. The permanent magnet type has a more compact structure and a lighter weight. In addition, the permanent magnet type does not require an individual control cabinet, which is the best choice for a limited space.
3. Cost: Since the core of the electro overband magnetic separator is the excitation coil, the cost will be much higher than that of the permanent overband magnetic separator.
Moreover, the electromagnetic type is usually equipped with a cooling system, including air cooling, oil cooling, forced oil cooling, etc., which makes the cost higher.
It is also obvious that the operating cost of the electro type is much higher than the permanent type, because it has higher power consumption when excitation.
4. Working hours: The continuous working time of the electro overband magnetic separator is lower than that of the permanent type. This is because the electromagnetic coil heats up after a long time operation, which will cause the decrease of magnetic field strength (unless with a forced oil-cooling), but the permanent type doesn't have that problem (the demagnetization rate of GTEK MAGNET® permanent overband magnetic separator will not exceed 5% in 8 years).
But everything has two sides. When we do not need the magnet force in some cases, but only run the belt conveyor, the advantages of the electromagnetic type are reflected. Because we can conveniently control the magnetic ON/OFF of the electromagnetic overband magnet, yet the permanent magnet type cannot, unless we move it somewhere else. Therefore, when the magnetic force needs to be switched frequently, the electromagnetic type is definitely a better choice.
5. Magnetic field strength: In the actual test, the field strength of electromagnet type is generally larger than the permanent magnet type. The maximum magnetic field strength of the forced oil-cooled electromagnetic overband magnet can reach 2500Gs, while the permanent magnet type can only provide up to 1500Gs.
Ferrite or Rare-Earth Permanent Overband Magnetic Separator
When choosing between ferrite or rare-earth permanent overband magnetic separator, we should first understand their respective characteristics:
What is a ferrite overband magnet?
Ferrite overband magnetic separator is the most traditional overband magnet, usually used to separate larger pieces of tramp iron, such as ReBar, beverage cans, large bolts, rods, etc. they are the more common permanent magnetic cross belts on the market. Its cost is relatively cheaper than the rare-earth type, but it has a deeper penetrating magnetic field. And it is usually larger than the rare-earth type and has stable and reliable performance.
What is a rare-earth overband magnet?
The emergence of rare earth overband magnets has given many mobile equipment industries a better choice, such as mobile crushers and mobile screeners. It satisfies the user's requirement for "small space". The rare earth type is usually made of neodymium magnetic material, which has stronger magnetic field strength and can separate the very fine iron impurities in the material.
However, a stronger magnetic field also brings disadvantages to it. First, the magnetic permeability of the rare-earth overband magnet is shallower, which means that when using the rare earth type, a lower suspension height is required. In addition, the rare-earth type cannot be used to separate heavy and bulky tramp irons, because a violent impact will not only damage the machine, but also affect the performance of the rare-earth magnet.
GTEK® hybrid overband magnetic separator
As a manufacturer specializing in the production of overband magnets, GTEK has already thought about whether the advantages of ferrite type and rare earth type can be combined. After years of research and experimentation, we have launched a composite permanent overband magnetic separator, which not only has the advantages of deep magnetic penetration and low cost, but also has a stronger magnetic field and a smaller volume. We apply this technology to all of our permanent overband magnetic separators, so that you no longer need to consider the complicated problem of choosing ferrite type or rare earth type.
So Which Specific Model?
In order to let you clearly learn about the differences between the models and make the selection easier, I will show the features of all models in the table below, I hope it will be helpful to you. You are also welcome to contact us directly to inform us your situation, and we will reply with the best solution and the most competitive price.
Why GTEK MAGNET's Overband Magnet?
As the top manufacturer of overbelt magnets in China, we have more than 20 years' manufacturing experience of conveyor belt magnetic separators. Meanwhile, we are located in one of the largest origins of rare earth materials in the world, which greatly expands our product price advantage.
At present, our products have been exported to more than 30 countries in North America, South America, Oceania, Southeast Asia, the Middle East, and Europe. We are also the designated overbelt magnetic separator supplier for many mobile crusher and wood grinder brands. Our annual output of overband magnets can reach more than 1000 sets.
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