How to Manage Precise Temperature Control of High Powered Lasers

In Booth B-8637, Glen Dimplex Thermal Solutions (GDTS; Kalamazoo, MI) showcases their new Intelligent Laser Cooling System (iLCS), an integrated cooling solution for high powered lasers that delivers smart technology, improved uptime and a reduced overall footprint. Industrial lasers are used for a variety of applications, from cutting, printing, and welding to marking and drilling, each with its own specific requirements. Regardless of the laser’s purpose, cooling at a consistent, precise temperature is key to the laser’s efficiency and total cost of ownership. The performance of industrial lasers is affected by the heat generated by the system. Increased operating temperatures also increase the laser’s wavelength, reducing the overall optical conversion in the process. Precise and consistent cooling allows each emitter to maintain a narrower band and improves alignment.

Changes in beam power levels and turning the beam on and off create wide fluctuations in heat load. Temperature fluctuations associated with these heat load changes can cause overheating of key laser components, such as the laser heads. Cooling at a consistent, precise temperature will improve the beam quality, as well as protect the laser system investment with the reduction of thermal stress. Reducing the thermal stress that causes component failures will improve the mean time between failure (MTBF) and ensure optimal laser performance. The type of cooling required is determined by several factors, including laser wattage, resonator efficiency, resonator and optics temperature requirements, and ambient temperature conditions. Ambient cooling systems are most effective at dissipating heat for, but not necessarily holding, precise temperature stability. When the air-cooled medium is not enough, these laser systems may use liquid-to-liquid cooling operations that can be combined with chilled facility water stemming from a cooling tower. Liquid-to-liquid chillers use a mechanical pump, reservoir, tubing, and fittings to transfer heat to facility water via a heat exchanger.

For laser systems where the resonator and optics operating temperature requirements are at or below ambient, vapor compression (VC) designed water chillers are typically used for cooling. VC water chillers embody a refrigeration system composed of a compressor, condenser, expansion valve and evaporator that transfers heat from the process cooling water directly to the air via an air-cooled condenser or to a facility chilled-water system through a water-cooled condenser. VC water chillers can handle very high heat loads and, when equipped with the proper control systems, are able to hold the process cooling water within very precise temperature tolerances < ±0.5 deg F. The iLCS is designed to partner with laser equipment for maximum efficiency and system life. This OEM-specific VC chiller incorporates technology to integrate better with equipment, and takes less time to install, setup, and operate.

Using machine-to-machine communication linked to building management systems, built-in electronic sensors monitor the tank levels, de-ionized conductivity level and cartridge filter, fluid pressure and flow, and automatically adjust the motorized hot gas bypass to modulate the refrigeration circuit, enabling precise temperature control. The iLCS incorporates one refrigeration circuit that can provide cooling to multiple fluid circuits, eliminating the need for multiple chillers. Another unique feature is the use of dual compressors to better match the variable heat loads, improve efficiency, and reduce component failure. The intelligent controller alerts users of the chiller health and predictive measures to prevent downtime. When the chiller needs maintenance, the interior design coupled with the use of wire harnesses aids the technician to quickly service the unit, limiting downtime. A range of sizes is offered, from 3 ton to 30 ton cooling capacities to meet the cooling needs of all laser systems. Custom color and private labeling options are also available.

Glen Dimplex Thermal Solutions, 2625 Emerald Drive, Kalamazoo, MI 49001-4542, 269-349-6800, www.dimplexthermal.com.