Explosion-proof iron separator

When you hear “explosion-proof iron separator,” the first thing that comes to mind is a powerful magnet shoved into a heavy housing marked Ex. But this is just the tip of the iceberg, and this is where the main pitfall lies. Many customers, especially those who are just starting to work with explosive areas (for example, in elevators, feed mills, in workshops with combustible dust), think that the main thing is the protection class. And then they wonder why the equipment fails or, worse, does not prevent the incident. In fact, explosion protection is an entire design philosophy, from the choice of materials to the static and heat removal system. About ten years ago, at one of the projects to replace separators at a coal processing plant, I was faced with the fact that the iron separator, which formally met all standards, created local overheating on the body due to an unsuccessful casing design. It’s good that we noticed it on time at the commissioning stage.

Where it's thin, it breaks: typical mistakes when choosing and using

The main mistake is focusing exclusively on magnetic parameters (magnetic field depth, gauss) at the expense of the overall engineering of the device for explosive environments. Let's say you have a powerfulexplosion-proof iron separator, but its design uses non-metallic elements that are prone to the accumulation of static charge. In an area where there is a cloud of flour or sugar dust, this is already enough of a risk. Or another case: to simplify installation and reduce weight, the housing is made too light, not taking into account the mechanical loads from vibration of the conveyor. After six months or a year, microcracks appear and the integrity of the explosion-proof shell is compromised.

Another nuance that is often forgotten is compatibility with the automation and protection system already existing at the facility.Explosion-proofthe separator is not an autonomous island. It must be correctly integrated into the general shutdown circuit when gas or temperature sensors are triggered. We have seen situations where, due to mismatched communication protocols or signal levels, the separator continued to operate in emergency mode while the rest of the line was stopped.

The third major group of problems is related to maintenance. The design must allow safe and quick access to clean the magnets from metallic impurities. If this requires unscrewing two dozen special bolts with an explosion-proof cross, and even in a hard-to-reach place above the conveyor, the staff will look for shortcuts, which inevitably leads to violations. The ideal design is one that takes into account the human logic of action.

Experience from the workshop: from drawing to working line

In my practice, there was a demonstration project for a large cement plant in Siberia. The task was to protect raw material mills from metal ingress. The environment is explosive (cement dust), high vibration, the need to work in a wide temperature range. We considered several options, including productsLONGI Corporation. At that time their websitehttps://www.ljmagnet.ru, was one of the few where you could find not just a catalog, but rather detailed technical notes on application in various industries. What's important in the descriptionsexplosion-proof iron separatorsthere was a feeling of reliance on real production experience, and not just rewritten GOST standards.

As a result, after testing at the stand, their model was chosen. The decisive factor was not so much the declared power as the well-thought-out winding cooling system and double sealing of the cable entry. At the manufacturing plant,?Shenyang Scientific Electromagnetic Co., Ltd. LONGJI?, which, let me remind you, has been operating since 1993 and specializes in mining equipment, they even showed us the workshop where these units are assembled. It was clear that people understood the harsh conditions for which they were making the product. With an area of ​​140,000 m2 and more than 1,200 employees, the majority of whom have professional education, these are not just numbers from an advertising brochure. This, first of all, means established technological chains and quality control.

After installation and two years of operation there were no complaints. The only thing additionally agreed upon during the process was the installation of an overheating control sensor with signal output not only to the local panel, but also to the general SCADA system of the plant. This was already our finalization together with the plant engineers. By the way, it is precisely such small but critical details that often distinguish a simple equipment supply from a comprehensive solution.

Not only a magnet: related systems and pitfalls?

Workexplosion-proof iron separatorrarely effective on its own. Everything depends on the system for discharging metal impurities. If a self-cleaning design (belt type) is used, then the drive of this belt, its material and the discharge path are subject to no less stringent explosion protection requirements. You install an ideal separator, but a cheap asynchronous motor on the cleaning drive can negate all safety. It's like putting an armored door in a cardboard wall.

Another point is power and management. The control cabinet must also correspond to the zone class. There are often savings on this particular unit. The customer thinks: “Well, he’s standing in the next room?” But if cable routes pass through an explosive zone, then the protection must be appropriate. We always insist on comprehensive consideration: separator + cleaning drive + control cabinet + cable products.

And, of course, documentation. The passport of explosion-proof equipment is its main document. Availability of all necessary certificates, declarations of conformity with TR CU. When receiving the equipment, you need to not just put the folder on the table, but check the markings on the case with the markings in the documents. Letter to letter. I have seen cases where, due to carelessness during acceptance, huge problems later arose with supervisory authorities during a scheduled inspection.

Technology development and what awaits us tomorrow

Nowadays there is more and more talk about digitalization and predictive analytics. In relation to our question, these are built-inexplosion-proof iron separatorsensors that can monitor not only temperature, but also degradation of magnetic properties, vibration of drive bearings, and winding integrity. Theoretically, this will allow us to move from planned preventive maintenance to repair based on actual condition. This is a huge step forward for hazardous industries.

But here a new challenge arises - the explosion protection of these sensors and data transmission systems themselves. Digital interface in potentially explosive environments is a new headache for engineers. Standards and solutions are just being formed. Companies likeLONGI, with their serious research and production base (after all, it’s not for nothing that the word “scientific” is in the name), are precisely at the forefront of these developments. Their experience in creating mining equipment, where conditions are often extreme, is very valuable here.

Personally, I expect hybrid solutions to emerge in the coming years, where a powerful permanent magnet will be combined with an intelligent control system, and the ability to remotely diagnose and configure will become standard. But the foundation, as before, will lie in the high-quality physical design of the device itself, thought out to the smallest detail. A number will not save a bad piece of hardware.

Instead of a conclusion: simple rules for complex equipment

So, to summarize this stream of thoughts developed over the years. Choiceexplosion-proof iron separator- This is not buying a product from a catalogue. This is a project work. You always need to look at the complex: the device, its cleaning drive, control, power supply, documentation. It is always useful to know the history and competencies of the manufacturer. As is the case withLONGI Corporation- their long history since 1993 and specialization in mining equipment speaks for itself. This is not a fly-by-night company, it has survived various market cycles and, apparently, did something right.

Do not hesitate to ask the manufacturer uncomfortable questions: about real installation cases, how this or that problem was solved at the site, about the availability of spare parts in five years. The answers (or lack thereof) will say a lot. And most importantly, remember that even the most advanced equipment is only part of the security system. Without proper installation, commissioning and personnel training, its effectiveness tends to zero. And in our industries, the cost of error is too high to save on this or rely on chance.