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What Is Magnetic Lifter? Types, Applications, History, a Guide
When it comes to heavy industry, involving steelworks, you need machinery that can handle large loads, a large capacity magnetic lifter that operates with speed and efficiency. You need the next generation in steel moving capabilities.
In this article, we’re going to discuss what a magnetic lifter does, how it works and what it’s used for. But first, here’s a quick answer to give you a quick overview, then we’ll dive into more detail…
What is a magnetic lifter? A magnetic lifter is a large scale heavy industrial machine that, with the use of high-performance electromagnets can quickly and efficiently move steel sheets or steel beams, with minimal effort by remote control, they can be switched on and off and can be controlled by just one person.
Sounds simple, but there’s more to this than you might think, so with that quick overview given, let’s dive into more detail around how these work and what they’re used for.
First, let’s discuss the technology behind magnetic lifters…
How does a magnetic lifter work?
Designs can vary depending on the application but they all work along with a similar concept. More on the types of applications later, but here’s how a magnetic lifter works.
A magnetic lifter is a chain, or series of highly charged neodymium cylinders or molded into other shapes. They’re suspended from a magnet crane.
These shapes comprise a retractable magnet, which, when turned in the “off” position reflects their magnetic force inward and is largely absorbed by the machine itself.
When these magnets are in the “on” position, the magnetic field is turned downward and will then attract any ferromagnetic steel objects toward them.
These magnets are extremely powerful and can carry up to 50 tons or more in weight – depending on which configuration, size, and design they’re placed in.
The cycle of operation
These magnets within a working environment operate like many other machines – or even people, or other equipment – that are moving items from one place to another.
The magnets are designed along specific operational routes and, in their most basic form, they’re engineered to “collect” at one end of the operation, and “deliver” at the other end.
The magnetic plate lifters or other lifting material designs are aligned above the load that’s to be collected, moved into place via remote control – operated by one person. They are lowered and the magnetic field is turned to the “on” position. At this point, they will be locked onto the load.
They can then be lifted, via pulleys or hydraulic systems and moved along rail systems to a second point where they will be lowered and the payload will be delivered. The magnets are then released, and the process begins again.
These, of course, are the operational stages of electrical magnetic lifters. Permanent magnetic lifters operate differently and are in a permanent state of magnetized, rather than switched on and off as is the case with electrical magnetic lifters.
Three main criteria for magnetic lifters
There are three main principles by which a magnetic lifter works by, in the area of special precautions that enhance safety, these numbers represent the rules to follow. Here’s a rundown on those three specifications…
The rated capacity represents the maximum capable working weight for any non-cylindrical objects, such as sheets of steel – using magnetic steel plate lifters, or steel beams
This represents the maximum working applicable weight for any cylindrical objects, examples pf these include pipes or other spherical based objects.
This is because cylinder-shaped loads offer much less surface area that is a lifter is able to grab onto. For this type of load, the equation you work to is generally ⅔ of the regular capacity of the magnetic lifter.
Max tear-off strength:
The idea behind the max tear of strength is that if enough force is applied to the payload of the lifter, then the item will detach (tear-off) from the magnetic field.
For a typical magnetic lifter, the force applied would be 3.5 times the Rated capacity (as outlined above) for the lifter. As an example, a lifter might be designed to carry a 1-ton load, if an additional 2.5 tons were added to the payload then you will likely reach the tear-off threshold and the load will detach from the magnetic lifter.
Be prepared to remove the old cumbersome methods of moving large plate and beam steel and look at electromagnetic steel as your labor-saving and preferred choice for large scale steel moving tasks.
Permanent magnetic lifters
Permanent Magnetic Lifters are mainly used to lift steel plates, blocks, press molds, etc. and load / unload in machines during handling operation. They can hoist moving iron blocks and other magnetic material. They are easy to operate and safe to handle and hence are widely used as lifting devices in factories, docks, warehouses and transportation industries
Magnetic lifter applications
Magnetic lifters have a wealth of suitable environments and offer distinct advantages over other older methods such as binding and slinging techniques. Here are a few applications where magnetic lifters are the best option, but there are many more…
- Larger applications such as steel plates, rounds or blocks, press molds, and machine loading or unloading.
- Commonly used near flame cutting environments and applications.
- The heavy lifting of materials during fabrication on or off-site
- Zero scratch marks for applications where components need to be scratch-free. This differs from binding and slinging techniques which can damage components.
- For use with a spreader beam, hanging multiple magnets for long plates, bars or even pipes
- For use with mobile crane applications
Although this is the high-level industrial use of electrical magnets, the use of electrical magnets goes back further in history with many applications already in use on a daily basis. Here’s some information on how electromagnets were discovered,
How magnetic lifters were discovered
As far back as 1820, the Danish scientist Hans Christian Ørsted discovered that electric currents create magnetic fields.
But the journey to complete the invention of electrical magnets, known commonly as electromagnets was an unintentional global collaboration of sorts – spanning many years and revisions…
Shortly after, it was a British scientist by the name of William Sturgeon who in 1824 invented what we know today to be the “electromagnet”.
The initial invention was shaped like an iron horseshoe, varnished to insulate it and wrapped around 18 times with bare copper wire. Passing a current through triggered the iron to become magnetic. This could be turned on and off by the introduction of current or no current.
In the 1830s, US scientist Joseph Henry improved upon this design further and began creating even more powerful magnets.
creating powerful magnets with thousands of turns of wire, including one that could support 2,063 lb (936 kg). The first major use for electromagnets was in telegraph sounders.
The concept of electromagnetism was further developed by French physicist Pierre-Ernest Weiss in 1906 and contributed to in the 1920s by Werner Heisenberg, Lev Landau, Felix Bloch – and other contributors too.
Magnetic Lifter Requirements
We hope this has been useful in understanding how magnetic lifters work, their applications and a little information on where they came from.
As experts in this field, we provide electrical magnetic lifter solutions for all types of uses and industries. If you need a custom design? Or a simple solution, we’re here to help, so why not contact us today, we’ll be happy to discuss your needs further.