Material handling has a major role to play in hazardous environments. There is a diverse range of industries where heavy-duty equipment, or explosionproof hoists and cranes are utilised. Such examples can include environments where hydrocarbon gases and vapours, dusts of coal, wood and some metals and combustible fibres exist.

Elsewhere, sectors where refurbishment and maintenance levels are high or in industries such as ship-building and repair are likely to call on explosionproof technology to carry out important processes.

It is therefore unsurprising that equipment that is used in such areas that are affected by these hazards must be specified and suitable for use by avoiding spark or flame generation that may ignite explosive mixtures or equally, by preventing contact between the two.

Diverse environments Without taking a broad-brush approach to the application of hoists in such environments, this technology can be divided into a range of different choices, namely air-powered (pneumatic) or explosion-proof electric, while hydraulic hoists that also require explosion-proof electric drives for the power pack and must use non-flammable hydraulic fluids.

The making or breaking of powered electric contacts can generate sparks that can subsequently ignite a hazardous atmosphere. Equipment that can generate hazardous sparks must be housed in an explosion-proof or flameproof enclosure.

Such an enclosure can ensure that no flame escapes into the wider hazardous atmosphere, even if the hazardous substance in question can enter the enclosure. Therefore, this must be strong enough to contain any explosion without losing its explosion-proof properties, and any joints used in its construction must have a construction that prevents the passage of flame to the general atmosphere in all circumstances. These hoists also arrive equipped with numerous safety features that include overload and over-speed protection in addition to on-the-spot safety readouts for instant troubleshooting. The manufacturer’s variable frequency drives options are available on monorail, top-running double girder and its deck-mounted Global King and World Series hoists. In addition, Columbus McKinnon’s explosion-proof Global King and World Series hoists can now be specified with spark-resistant options, which offer added safety and protection in environments where flammable gases and liquids are present. Central to these upgrades are bronze sheaves, bronze trolley wheels, copperplated or bronze load hook, and drop stops with rubber bumpers.

Variable capacities

For Konecranes, the EXN electric chain hoist is a key element of its explosion-proof offering. The product is an XN hoist that is fitted with EX components, which is pitched as a "dependable", explosion-proof hoist. The EXN, which can lift up to 10 tons, is pitched at companies in the energy production, chemical handling and light manufacturing sectors. The EXN hoist that complies with the EU ATEX directives, follows European standards for explosive atmospheres, that include the EN60079 series, and can also be made for IECEX approval on request.

According to Konecranes, its EXN electric chain hoist is approved to handle up to 5 metric tons in Zones 1 and 2 and up to 10 metric tons in Zone 22 applications. End users can specify the product in stationary; hook suspended, push, or motorized trolley versions with a low headroom trolley for Supersack handling also available, if required.

Elsewhere, MHE Demag offers its Ex CH Chain hoist, which is tailored to handle capacities up to 4 tons. The Ex CH is type tested by an independent ATEX notified body and provides a "lightweight and compact design" coupled with fixed suspension, manual push, geared and motorised trolley for a diverse range of applications.

Other features include a minimum IP65 rating for electrical enclosure while all motors are equipped with Insulation Class F and temperature rise class B to provide a longer operational life span. In addition, it features a brake with asbestos-free lining that activates automatically in case of power failure.

Proven technology

One manufacturer that is "Proven in practice" is JD Neuhaus, which supplies its JDN Air Hoists Profi Series hoists for environments where safety is a priority. According to the manufacturer, the Profi series scores well with its 100% duty rating and offers explosion protection as standard, which means these air hoists are especially suitable for applications in hazardous areas. Elsewhere, its JDN Monorail Hoists are available with air or hydraulic drive for customers in the offshore industry, or for those moving heavy loads in reduced spaces.

"Depending on the application JDN Monorail Hoists can be used in tandem. For example: Working in parallel for BOP handling systems. Working in tandem and connected by a tie bar for handling grinding rollers in the cement industry," the company said.

These are ideally suited for working in hazardous areas such as explosion risk environments as well as those where there is an insensitive to humidity, dust and temperatures from -20°C up to +70°C. R&M continues to enjoy success with its Spacemaster EX, which is the hazardous location version of its Spacemaster SX hoist. This includes a large drum diameter that comes as standard with lifting capacities ranging from 1600 — 20,000 kg and lifting speeds from 3/0.5 — 19/3 m/min.

Finally, 2013 was a record year for industrial equipment manufacturer Cervis, which managed to expand in its core markets, release new technologies and capitalize on its dedication to customer service.

The company is focused on releasing new concepts and technologies to the North American market in partnership with IKUSI of San Sebastian Spain. In the material handling markets specifically we look to introduce a higher degree of control and safety for standard applications, create innovative, full featured offerings with the new i-Kontrol console box product line and continue to grow the market of intrinsically safe / explosion proof applications.

"Year after year we have grown our expertise in the material handling sector and our team of commercial and technical staff continue to demonstrate to the customer base that Cervis is poised to provide high end products and service. Moreover, our expertise allows us to serve both ends of the market," the company said.