Open your mind to enclosures because a raft of advances means process engineers can pick the right protection for their equipment and operating situation, explains Greg Pitcher.
You wouldn’t buy a Rembrandt original and hang it in a damp garage with a rusty door – it’s widely understood that environment is important to protect the characteristics of delicate and treasured possessions.
Looking after the critical and expensive instruments in your process plant is no different.
As well as proactively maintaining equipment, a key step in caring for it is making sure it is kept in well thought out enclosures. As well as offering protection from outside forces, modern enclosures can boost an operating environment through drying, cooling and a range of other interventions.
“Failure of just one instrument could be enough to bring part or all of a process to a stop with huge cost implications for the downtime,” says Gavin Faulkner, UK sales director of German equipment protection provider Intertec. “In other areas, failure might have catastrophic consequences such as fire or explosion.”
The reliability and correct functioning of these systems depends on keeping components within operational temperature parameters
Gavin Faulkner, UK sales director, Intertec
The firm warns that it is easy for condensation to form inside an enclosure as temperatures cool during factory overnight downtime, causing an electrical short circuit.
At the other end of the scale, high temperatures during a summer daytime shift might mean cooling is required within the enclosure to prevent overheating.
“Thermal problems are the direct cause of most malfunctions and shutdowns of electronic and electrical equipment,” says Faulkner. “The reliability and correct functioning of these systems depends on keeping components within operational temperature parameters.”
Feeling the pressure
The demands on enclosures are particularly great in certain sections of the process industry.
“Many of the most significant process control and instrumentation projects of current times involve installing plants in extreme locations,” says Faulkner. “Dealing with the intense cold of an Arctic environment demands very high performance insulation.”
Intertec uses lightweight glass-reinforced plastic (GRP) for enclosures as it has a high thermal resistance and can be fabricated to enclose high-performance insulation. This can be bonded or injected into place, removing the need for fixings that can create thermal short cuts.
Another place where challenging conditions are found is North Sea platforms. In such wild, wet environments, Intertec often uses GRP with a specially developed UV-resistant gel-coat applied to surfaces to maximise the lifetime of the enclosure.
Intertec has also developed a system allowing passive cooling to be used in the hottest, driest regions of the world.
A powered chiller can increase the performance of the media cooling the enclosed environment. “If a cooling system is configured as a hybrid solution combining both passive and active cooling, each element of the system can be scaled down so that the active cooler only needs to help out during peak summer temperatures,” says Faulkner.
Hole counting on the new frame sections means we can now pinpoint precisely where enclosure mounting parts should go
Eugen Franzen, team leader for mechanical installation, Controller Steuerungstechnik
Tough environments have inspired other developments in the field. Texas-based Larson Electronics recently released an explosion-proof enclosure for use in hazardous locations. This cast aluminium enclosure is made to hold electrical equipment indoors or outdoors where flammable gases, vapors or dusts are present.
The EPL-AEB-16.16.6-1X2TC cast alumin-ium enclosure has stainless-steel bolts and a weatherproof gasket suitable for chemical manufacturing plants, power plants and paint spray booths among others, says Larson.
Meanwhile – as well as going to more extreme places – manufacturing is being used for an increasing range of jobs.
Innovation is happening across the industry. Rittal ensured its VX25 large enclosure system underwent a range of extreme tests to ensure it was ready for extreme environments. Frame structure, doors, panels and gland plate, as well as external parts such as hinges and comfort handle variants, are all made of stainless steel.
While the sheet steel and stainless steel enclosure types have Ingress Protection 55 (IP 55) and National Electrical Manufacturers Association 12 (NEMA 12) status as default, the NEMA 4X with its IP 66 accreditation offers even greater resistance to the elements.
In order to achieve this, the enclosure underwent a water jet test alongside checks of dust protection, corrosion resistance and anti-ice damage capabilities. So engineers know the electrical and electronic equipment in the VX25 is protected from dust and water, even in the most demanding of environments.
The hose-down test involved using a stream of water with a flow rate of more than 240 litres per minute, confirming no water would penetrate the enclosure under comparable conditions.
Despite the impressive technological breakthroughs and advances, sometimes it is unexpected features that make the difference when it comes to enclosures.
Controller Steuerungstechnik, part of the German Schaper Group, was won over by a minor detail, explained Eugen Franzen, team leader for mechanical installation: “Hole counting on the new frame sections means we can now pinpoint precisely where enclosure mounting parts should go. Previously, we often had to revisit such details, which always involved extra work.”
As the search for game-changing detail continues, Hitaltech has produced a circular enclosure which, it says, is suitable for a range of automation functions and majors on looks and functionality.
“Now the aesthetics of building automation enclosure design are catching up with the capabilities,” says the company. “The simple user interface hides a multitude of options... measurement displays, settings for lighting or temperature, movement sensors, access controls, security camera controls and more.”
Enclosures manufacturers are certainly thinking outside the box to look after what’s inside it.
