Environmental containers and fire protection

The Dutch company KOK Milieuopslagsystemen from Beneden-Leeuwen in the province of Gelderland is an expert in the field of customer-specific storage systems, including for environmentally hazardous substances. For the storage of chemicals, oils, paints, lubricants and other materials, KOK develops and produces special environmental containers that can hold between 4 and 24 pallets in quadruple spacing. The dimensions of the containers are based on the dimensions of the pallets or packaging. The best-known units, because they are not only common in Europe, are Euro pallets with a height of 120 cm or 180 cm for aerosols, block pallets, chemical pallets, CP-9 pallets and intermediate bulk containers. The latter are also known as standard IBCs or double-walled IBCs and have a height of 160 cm.

Wanted: Perfect stoppers for added safety

In order to comply with standards and guidelines for large containers, such as the Dutch volume limit according to PGS 15, these systems, also known as shelf containers, are usually equipped with a fire-resistant partition wall. In an emergency, this creates two separate fire compartments in an environmental container, which on the one hand delay the spread of fire and on the other hand make it easier to fight one or more sources of fire.

Kamiel Oosterwaal, Managing Director, and Wayne Benoit, Sales Manager at KOK, have developed a safety feature called Fireguard as additional fire protection for their environmental containers. This is a special fire-retardant sliding door system used in the large hazardous materials containers, which has been inspected in accordance with the European door testing standard EN 1634-1 and classified to EI-1-60 by the fire protection and certification specialists Efectis. "These abbreviations for classifying construction products and types of construction in terms of their fire behavior were adopted from French," explains Wayne Benoit, with the E standing for Étanchéité or room closure and the I for insulation in the sense of thermal insulation. "We fill the steel structure with the active coolant Firex and thus prevent our environmental containers from collapsing in the event of a fire," adds Kamiel Oosterwaal and explains: "Our doors can stop fire for at least 60 minutes both from the inside out and from the outside in, which is an essential condition for our racking containers to comply with the PGS 15 directive that applies in our country."

Practical and safe in operation, ACE's single or double-sided door dampers are suitable for manually or automatically operated swing and sliding doors in building services and many industrial sectors. © ACE

As the managers report, another requirement for manufacturers of hazardous goods containers of this size is that the doors installed must be self-closing in an emergency. The sliding design chosen by KOK for this purpose ensures that the doors close under the influence of counterweights, which cause the doors to move at a uniformly accelerated speed. As the fire protection requirements stipulate that the doors must close completely within 20 seconds, the closing speed can be up to 1 m/s, depending on the door width. And because the fire doors of their Fireguard system vary in size and mass between 300 kg and 800 kg, the two set out to find suitable stoppers in view of such accelerated mass forces in order to provide the best possible protection for the end positions of the rack container frame filled with Firex. In the course of their research, they found the Dutch website of ACE shock absorbers and immediately came across several suitable alternatives for the desired rebound-free protection.

Dampers for sliding doors of different weights

Wayne Benoit cites ACE's personal and quick advice as an additional plus point in the search for a suitable partner for this part of their design: "We were very pleased that ACE has its own sales team in the Netherlands and that Ralf Küppers, as one of the company's representatives, immediately suggested that it would be best to design the right components on site." So it wasn't long before the sales engineer, who was born in Germany and trained academically in the Netherlands, was able to see the Fireguard sliding door system in action. He recalls: "When you stand in front of such a large hazardous goods container, the dimensions are impressive. With their two levels and access via two sliding doors, the KOK racking containers offer enough space for 12 large intermediate bulk containers or, alternatively, twelve cubic tank containers for liquids. You can't help but think of the best protection for the environment and equipping the doors with the highest quality components possible." This also applies to KOK as a manufacturer because customers can choose from various additional options such as ventilation, cooling, heating, lighting and slatted floors when customizing containers.

Self-closing in an emergency

Ralf Küppers mentions another criterion for the appropriate equipment with machine elements from ACE: "The special type of storage in this application requires the doors to be self-closing in an emergency. The doors must also not rebound from the frame before closing, so our TUBUS structural dampers, for example, were out of the question from the outset." Instead, the team decided to use ACE door dampers to control the closing torque because, according to Ralf Küppers, the TDE-28-70 dampers used offer the customer a high degree of flexibility with the different masses and sizes of the doors thanks to their adjustability. The energy absorption of the recommended types is between 75 Nm/stroke and 190 Nm/stroke. And as the KOK sliding door system is driven by counterweights of different weights, these single or double-sided door dampers can be adjusted accordingly by turning the extended piston rod on the knurled head. As the damping can be precisely adjusted to the required forces using tooth adjustment, the exact adjustment is only made on site depending on the container and sliding door size. This variability is further enhanced by the available stroke lengths of 50 mm to 120 mm.

Another advantage praised by those responsible at KOK is that the adjustability of ACE door dampers means they have to keep fewer models in stock. Their assembly teams also save space in their vehicles. With the now tried-and-tested door dampers, they can be sure that they have the right models in the vehicle when assembling impact weights of up to 7,000 kg, even with differently dimensioned environmental containers. The fact that every ACE door damper has a high-quality, durable design with a hard chrome-plated piston rod and galvanized steel cylinder tube provides further peace of mind.