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Keeping it Cool with Vortex

15/02/2022

The Struggles of Natural Convection Cooling

Thermal testing has proven that natural convection cooling is not adequate for today’s smaller, high-power-density enclosures. Heat dissipation by forced convection (fan cooling) is the most frequently used method of cooling. Forced air-cooling systems can provide heat transfer rates that are ten times greater than those achievable with natural convection and radiation, but even this is not adequate to cool faster electronic components when they are located in hostile plant environments.

It is necessary to lower the internal enclosure temperature to below the room temperature to reduce hot spot (junction) temperatures and prevent control failure on higher density controls. Research by control manufacturers has shown that for each 18ÂșF (10ÂșC) increase in temperature, online production shut-downs will occur twice as often — increasing the failure rate of electronics by 40%. Most manufacturers of electronic components specify 104ÂșF (40ÂșC) and 90% humidity for proper operation.

The Problem With Forced-Fan Air

The never-ending pressure to reduce the cost and size of electronics while increasing speed and complexity has created a significant design dilemma. Forced-air fan cooling usually is selected by designers because fans are relatively inexpensive and easy to install.

Unfortunately, the factory air pulled into the enclosure by the fans usually contains just enough nearly invisible oil aerosols to coat the surfaces of sensitive and expensive electronic boards in control enclosures. This light surface coating of oil attracts and holds dust. The dust eventually forms an insulating blanket over the board, promoting heat buildup and eventually failure.

The Benefits of Vortex Cooling

Consider vortex cooling. A Vortex A/C Enclosure Cooler uses a vortex tube to convert a filtered, compressed air supply into refrigerated air without the use of electricity, ammonia, or other refrigerants.

How Vortex Tubes Work

The vortex tube creates cold air and hot air by forcing compressed air through a generation chamber which spins the air centrifugally along the inner walls of the tube at a high rate of speed (1,000,000 rpm) toward the control valve. A percentage of the hot, high-speed air is permitted to exit at the control valve. The remainder of the (now slower) air stream is forced to counter flow up through the center of the highspeed air stream, giving up heat, through the center of the generation chamber finally exiting through the opposite end as extremely cold air.

Both the high-speed air and the slower-moving air stream rotate at the same angular velocity. This is because intense turbulence at the boundary between the two streams and throughout both air streams locks them into a single mass (as rotational movement is regarded). The slower-speed inner stream is a forced vortex because its rotational movement is controlled by an outside influence other than the conservation of angular momentum. Learn more about this phenomenon here.

The cooled air produced by the tube inside the enclosure cooler is discharged into the enclosure while hot air in the enclosure is vented outside the box into the surrounding area through a built-in relief valve. The built-in relief valve and the cooler-to-enclosure seal maintain the NEMA rating integrity.

Air introduced into the enclosure is filtered before it enters the vortex cooler, creating a clean, cool, and controlled environment inside the enclosure helping to keep controlled processes up and running. An added benefit is that the enclosure cooler produces a slight positive pressure inside the cabinet to keep out dust and dirt.

Shop Vortex Exclosure Coolers

Vortex A/C Enclosure Coolers are available for NEMA 4, 4X, and 12-rated enclosures and our HazLoc Vortex A/C models are available for enclosures in Class I Div 2, Groups A, B, C, and D locations, Class II Div 2, Groups F&G and Class III locations.

Home > Blog > Keeping it Cool with Vortex

Keeping it Cool with Vortex

15/02/2022

The Struggles of Natural Convection Cooling

Thermal testing has proven that natural convection cooling is not adequate for today’s smaller, high-power-density enclosures. Heat dissipation by forced convection (fan cooling) is the most frequently used method of cooling. Forced air-cooling systems can provide heat transfer rates that are ten times greater than those achievable with natural convection and radiation, but even this is not adequate to cool faster electronic components when they are located in hostile plant environments.

It is necessary to lower the internal enclosure temperature to below the room temperature to reduce hot spot (junction) temperatures and prevent control failure on higher density controls. Research by control manufacturers has shown that for each 18ÂșF (10ÂșC) increase in temperature, online production shut-downs will occur twice as often — increasing the failure rate of electronics by 40%. Most manufacturers of electronic components specify 104ÂșF (40ÂșC) and 90% humidity for proper operation.

The Problem With Forced-Fan Air

The never-ending pressure to reduce the cost and size of electronics while increasing speed and complexity has created a significant design dilemma. Forced-air fan cooling usually is selected by designers because fans are relatively inexpensive and easy to install.

Unfortunately, the factory air pulled into the enclosure by the fans usually contains just enough nearly invisible oil aerosols to coat the surfaces of sensitive and expensive electronic boards in control enclosures. This light surface coating of oil attracts and holds dust. The dust eventually forms an insulating blanket over the board, promoting heat buildup and eventually failure.

The Benefits of Vortex Cooling

Consider vortex cooling. A Vortex A/C Enclosure Cooler uses a vortex tube to convert a filtered, compressed air supply into refrigerated air without the use of electricity, ammonia, or other refrigerants.

How Vortex Tubes Work

The vortex tube creates cold air and hot air by forcing compressed air through a generation chamber which spins the air centrifugally along the inner walls of the tube at a high rate of speed (1,000,000 rpm) toward the control valve. A percentage of the hot, high-speed air is permitted to exit at the control valve. The remainder of the (now slower) air stream is forced to counter flow up through the center of the highspeed air stream, giving up heat, through the center of the generation chamber finally exiting through the opposite end as extremely cold air.

Both the high-speed air and the slower-moving air stream rotate at the same angular velocity. This is because intense turbulence at the boundary between the two streams and throughout both air streams locks them into a single mass (as rotational movement is regarded). The slower-speed inner stream is a forced vortex because its rotational movement is controlled by an outside influence other than the conservation of angular momentum. Learn more about this phenomenon here.

The cooled air produced by the tube inside the enclosure cooler is discharged into the enclosure while hot air in the enclosure is vented outside the box into the surrounding area through a built-in relief valve. The built-in relief valve and the cooler-to-enclosure seal maintain the NEMA rating integrity.

Air introduced into the enclosure is filtered before it enters the vortex cooler, creating a clean, cool, and controlled environment inside the enclosure helping to keep controlled processes up and running. An added benefit is that the enclosure cooler produces a slight positive pressure inside the cabinet to keep out dust and dirt.

Shop Vortex Exclosure Coolers

Vortex A/C Enclosure Coolers are available for NEMA 4, 4X, and 12-rated enclosures and our HazLoc Vortex A/C models are available for enclosures in Class I Div 2, Groups A, B, C, and D locations, Class II Div 2, Groups F&G and Class III locations.