Food & Beverage Industry

The grain silos are a store or a place outside or inside a building, in which food industry products are stored. such as wheat, corn, rice or other similar products. Grain stored into silos inevitably generates deposited layers of dust, which can become a permanent cloud. This combustible cloud, dispersed in the air, forms an explosive atmosphere and may generate the danger of explosion.

Moreover, the large size of the warehouses and the mechanization of the processes such as the collection and handling of wheat and its derivatives have increased the danger of explosion of dust clouds that can occur in the presence of sparks or electrical arcs.

For instance, all the loading/unloading operations are carried out generally with mechanical means such as pipes, conveyor belts, augers, etc..., through loading inlets placed in the upper part of the silo tower. During such operations, dust is dispersed in air and, due to their low specific weight, wheat and cereal dusts may remain suspended in the air for long periods generating explosive atmospheres.

Therefore, all electrical and mechanical equipment must be designed and manufactured in accordance with the specific standards for explosion protection, to avoid any ignition.

The classification of hazardous areas in grain storage areas according to IEC 60079-10-2:

• Internal volume of the silo - Zone 20
• Loading and unloading areas (feeders and hoppers) and adjacent areas - Zone 21
• Volume around the area 21 with an extension of a few meters - Zone 22
• Places where dust can be deposited in layers - Zone 22
• Deposits of packages subject to breakage - Zone 22

Food manufacturing plants use raw agricultural products and turn them into ingredients for finished products. Very common substances such as wheat flour, cocoa powder, spices, icing sugar, tea, coffee…  increase explosion risks when treated in powder form. During milling, transformation, transport processes, a myriad of small-sized particles is produced. This results in the accumulation of dust in the workshop. The particles remain in suspension in the air. An explosion can happen anytime during the running processes in which motors and electrical switchgear require electrical power. This is the reason why employers need reliable electrical equipment.

To identify all potentially explosive areas, employers need to carry out an assessment of the plant hazards for the risk of explosion, due to the presence of combustible dust. They should specifically consider:

• all processes that use or produce combustible dusts,
• materials that can become combustible when they are finely milled,
• hidden areas where combustible dusts may accumulate and potential ignition sources.

After evaluating the risks of the presence of combustible dusts and identifying the dangerous positions, appropriate solutions in compliance with the provisions of the EN 60079-10-2 standard can be selected.

The classification of hazardous areas in food processing plants according to IEC 60079-10-2:

• Internal volume of processing machines - Zone 20
• Loading and unloading areas for flour, sugar, etc… - Zone 21
• Volume around the area 21 with an extension of a few meters - Zone 22
• Deposits of packages subject to breakage - Zone 22

In this scenario, all Ex electrical equipment need to be robust, reliable and must comply with the very strict hygiene standards in force in this sector. For instance, during cleaning activities of production site, all the machinery, lighting fixtures and electrical power distribution panel need to resist corrosion and withstand high temperature. This is due to the huge amount of cleaning agents and the steam-high-pressure washers used during the cleaning process.

When it comes to beer and spirits manufacturing facilities, all types of flammable materials (vapor, dust and gas) necessary for an explosion are present:

1. The production of beer and spirits produces solutions of ethanol, which is a highly flammable liquid and can release flammable vapors during distillation and storage processes.
2. Raw materials for fermentation and mashing processes involve the handling, long-term storage, and milling of wheat and barley, which generate flammable dust.
3. Grain roasting and drying require huge quantities of fuel, which is usually natural gas.

For these reasons, it is of critical importance to install the correct Ex-proof electrical equipment to prevent any explosion to occur. 

The classification of hazardous areas in distilleries:

• Distillation areas – Zone 1
• Barrel storage areas – Zone 2
• Loading and unloading areas for wheat and barley – Zone 21
• Storage areas for wheat and barley – Zone 22

The recommended material to be used in food & beverage production plants is the stainless steel which offers an ideal solution to resist the chemical action of acid and basic substances which are part of the ingredients we eat and drink.

Technor Italsmea can supply a full range of stainless steel Ex-proof enclosures, lighting fixtures and fittings:

• In full compliance with ISO 9001, ATEX, IECEx and EAC requirements,
• For installation in Zones 1, 2, 21, 22 & non-hazardous areas,
• With high resistance to high temperatures,
• With high resistance to corrosion (which can be further improved with electro-polishing treatment),
• Designed to be robust, durable and reliable over the years,
• With long lifetime and low power consumption,
• With low costs of ownership and maintenance,
• Highly recyclable, when product lifetime is over.