A Weld Camera, like most electronics, needs to be kept from getting too hot (typically not greater than 50 ºC within the camera electronics or greater than 40 ºC in the internal camera frame) to minimize the electrical noise of the video signal and extend the lifetime of sensitive electronics such as the LED light sources.
Therefore, Weld Cameras need to be equipped with a form of cooling that allows for the camera to run indefinitely even in high-temperature environments. This is done using either air (with either passive or active cooling) or liquid cooling.
Usually the cooling medium flows through a channel that is isolated from the optical and electronic components of the camera, keeping everything cool via convection, while keeping the optical and electronic components free of contamination.
Passive Air Cooling
Passive Air Cooling refers to the use of compressed air fed directly into the camera to provide a flow of air through the Weld Camera. If compressed shop air is used, the ambient air temperature should be less than 25 ºC because the compressed air temperature is close to the ambient temperature of the welding environment and needs to be under 25 ºC to be an effective cooling medium.
The compressed air should be filtered to prevent build-up of a film of dirt on the internal cooling passages of the camera body, as this will reduce the cooling efficiency. If there is a separate cooling chamber in the camera, the air does not need to be dry to be used. However, because of the typical small temperature differential between the incoming cooling air and the camera frame, a large air flow is required to maintain a cool camera, representing a significant operational cost.
Active Air Cooling
A better solution to cool a Weld Camera is to use Active Air Cooling. If the ambient temperature in the vicinity of the camera is above 25º C, Active Air Cooling is the only air cooling option. The most common way to provide Active Air Cooling is to use a device called a vortex cooler—a mechanical component with no moving parts but which takes in compressed air and divides it into two low-pressure air flows – hot and cold.
Within the vortex tube, the air flow is converted into a very-high-speed swirl (vortex) and the air in the vortex separates into a high-temperature zone at the outside and a low-temperature zone at the center. The unit can be adjusted to provide very cold air that can then be fed into the Weld Camera for cooling.
Cooling with a vortex cooler is extremely inefficient, using a high volume of compressed air that can mean high operating costs in the long run. However, it does provide a very cool air source to cool the Weld Camera in even very-high-temperature ambient environments.
Active Cooling for XVC-O with Vortex Cooler
Water Cooling
Water cooling is the most efficient way to cool a camera. Because of the very efficient thermal transfer between the camera cooling channel and the water, and the high heat capacity of water versus air, water at 32 ºC can be used to maintain the camera frame at 40 ºC or less.
If a cooling water supply is already being used to cool some welding system components, the additional cooling load from the camera will be insignificant. If a main water supply at 32 ºC or less is available, 2-3 litres/minute is sufficient to cool the camera and the water can be recirculated through a water chiller—a standard component that is readily available and reasonably priced. The cooling system cost can then be reduced to some very simple plumbing and simple equipment.
Conclusion
The XVC-O Weld Camera from Xiris uses a sealed chamber to provide cooling to the camera, thereby eliminating the potential to contaminate the optics and electronics from the cooling medium. Both Air (Passive or Active) and Liquid cooling options are readily available, providing the best solution to fit each fabricator’s needs.
