kubler articles

Mining Is Back

Kubler 9/1/2014

Mining Is BackThe safety provisions in force lead to quick changes in industrial machines and plants. This is why the sensors specialist Kubler offers a wide range of explosion-proof encoder versions and constantly develops his portfolio. It even encloses the special category Explosion protection for the mining industry.

A look at the large variety of explosionproof encoders shows the wide global orientation of the Company: it reaches from incremental and absolute singleturn and multiturn encoders up to shaft or hollow shaft versions, always in compliance with the relevant international provisions, and for many different zones. It also includes special encoders for the mining industry, which ensure safety in accordance with SIL2 and SIL3.

"We have been for many years specialists for explosion-protected encoders and we are offering them since 1997" explains Arnold Hettich, Product Manager Position Motion Sensors at Kubler. The development of suitable solutions meeting the highest requirements of the mining industry is a declared goal of the Company.

One of the first safety systems in mines was yellow and a talented singer. It was the canary. They entered the mines with the miners and they warned them against the feared firedamp underground. Due to its challenging working conditions, mining has always been marked by a particular innovative drive and technical progress.

Also firedamp - the repeatedly occurring explosions and its causes have been seine extensively researched. With such success, that the last explosion in a German mine took place over 40 years ago, and that this industry implemented safety provisions, which are considered worldwide as an example by other sectors.

The aspect and the work in the seams have changed too: while, only 30 years ago, the miners were still mining coal or minerals with pneumatic hammers, today, fully automated steel "moles" are digging their way. Mechanization is the key to high productivity and operational safety. So today, the face operations, that is to say the underground work processes in the seams, are generally controlled from the surface.

The ATEX family extends for the mining industry

The new ATEX is in force within the EU since 2003 for the explosion protection of electrical plants: it now also applies to the mining industry. Besides, it covers all other explosive areas, such as the dust explosion protection. "With its ATEX/IECEx approval, the large Sendix 70xx encoders family, now also including 71xx, can be used throughout Europe. Among the encoder manufacturers, Kubler has one of the most extensive ATEX/IECEx portfolios", reports Arnold Hettich, explaining that the Sendix encoders can be combined in a modular system to meet the widest variety of requirements.

"Moreover, the number of variants of the ATEX/IECEx standard sensors is constantly increasing. We currently have the Sendix 70xx/71xx with hollow shaft - ideal for explosion-protected motors - in our new products pipeline. The fact that Kubler extended its ATEX/IECEx products range now especially for the mining industry has a simple reason: "Mining became meanwhile again an industry of the future in Germany," according to the product manager.

Almost unmanned seams or driverless conveying systems belong today to everyday high tech for the miners. The cutter controls detect the limit between the mineral and the host rock by themselves and extract the mineral selectively. The volume and weight of the detached material are measured automatically and the cutter control is optimized according to the capacity of the conveyors and of the bunkers.

Modern extraction methods are particularly cost-efficient: they are energy-efficient and reduce the wear of the equipment while constantly increasing the production. Hettich: "The worldwide trend towards higher mining depths led to the adoption by the mining industry all over the world of the solutions developed in the German mining industry. These are now setting new standards."

It is interesting to note that the German mining industry still is considered as a dying activity, while, in many other parts of the world - due to the hunger for raw materials and energy - it is seen as an industry of the future. "Therefore, the mining knowhow accumulated over centuries in Germany is demanded as never before. The German engineering, and, due to the stringent European directives, first of all the safety technology, are currently becoming an export hit" concludes Hettich.

Ex provisions for all components

Wherever electrical motors are used in potentially explosive atmospheres, ATEX/IECEx imposes specific provisions for all components used. The specific operating conditions of mining place highest demands on the drive systems used, reaching from the "Flameproof enclosure" type of protection up to "Increased safety" (Ex e). With the Ex e type of protection, explosion safety is achieved with measures that aim to prevent unacceptably high temperatures and the creation of sparks or arcs inside and on external parts of the motor.

Perfectly matched components and units make sure that the motor can never reach a critical temperature in operation. Thanks to its comprehensive ATEX/IECEx encoders range, Kubler is able to supply and integrate the suitable explosion-proof sensor for almost all power ranges and applications. Within the explosion groups, the equipment is classified in Equipment Group I and Equipment Group II. Whether gas or dust atmosphere and independently of the type of protection, the Sendix 70xx encoders meet all requirements of the directives for Equipment Group II.

This applies to the higher-risk areas 1 + 21 as well as to the lower-risk areas 2 + 22. The Kubler-Sendix 71xx encoders meet all requirements of Equipment Group I Mining M2 and are therefore suitable for firedampendangered mines, where only electrical equipment belonging to Equipment Group I are used.

Safety hides in the details

With almost 20 years of experience in the manufacture of Ex-certified encoders, the sensors specialist from Villingen- Schwenningen is convinced that, especially in extreme operating conditions with high safety demands, the selection of the components is always also a question of a "good feeling": "No compromises are allowed here, confidence and every detail count," emphasizes Hettich.

In the explosion protection area, Kubler provides perfect solutions thanks to its components matched up to the tiniest detail. "These products therefore make a significant contribution to the economical success of a project." A specially trained "Ex officer" is available at Kubler for all questions relating to ATEX/IECEx encoders. In the mining industry, the ATEX Sendix 71xx are used as well in electrical motors in the pits as for the equipment of the fuel mill and of the pumping stations. They control the conveyors and vehicles in real-time. They measure speeds and ensure trouble-free positioning of the mobile platforms used for drilling operations when driving advance headings.

Whatever the use, the ATEX and IECEx M2 approvals guarantee safety and worldwide compliance with all Ex provisions. Whether on extraction lines or in mines with auxiliary ventilation, the Kubler encoders of the ATEX Sendix 71xx series are part of the ultramodern safety technology. Their housing, in the proven Sendix design, ensures stability and smooth operation - whether in dust atmosphere or under pressure. Their field of application lies increasingly in the cutting-edge technology developed and optimized against the background of German mining history, which provides today solutions demanded all over the world. It could almost seem that the old "coal penny" is paying off only now.