Winter Anti-freezing Precautions for Chillers

Dear SKY FlRE's family

Firstly, we would like to express our gratitude for your strong support to SKY FIRE! Due to the harsh weather conditions this year, many regions are experiencing temperatures below 0°C. In order to effectively prevent freezing damage to the water chiller and laser during long periods of shutdown, we are issuing this blog to inform you about the drainage and anti-freezing methods for the water chiller and laser in winter. We kindly request that all production companies pay high attention to this mater to avoid unnecessary losses (especially with the upcoming Chinese New Year vacation, it is crucial to check the drainage status of the equipment before the break to prevent freezing).

1. Hazards of Freezing
2. Internal water system of the laser may explode.
3. Internal components of the laser may be damaged.
4. OBH front-end gemstone may crack due to freezing.

Anti-Freezing Measures

1. Install air conditioning or heating equipment to maintain the ambient temperature at around 10 degrees Celsius. (Ensure that the air conditioning and heating are turned on 24 hours a day.)
2. When the equipment is not in use for a short period of time, run the water chiller for 24 hours so that the flowing water does not freeze. (If the ambient temperature is below 4 degrees, the water chiller needs to be running for 24 hours. Note: The above two solutions are for short periods of equipment non-use. You can choose one of them.
3. When not in use for a long period of time or during a power outage, empty the water from the water chiller tank and the laser.
4. Add anti-freeze fluid.

Maintenance in Winter (Adding Anti-freeze Fluid)

To prevent freezing, it is recommended that users add anti-freeze fluid to the cooling water of the laser when the temperature reaches zero degrees Celsius or below.

Selection of anti-freeze fluid: It is recommended to use anti-freeze fluid from Crane Company. Genuine Crane anti-freeze fluid is pale yellow in color and is generally added in a ratio of 3:7, with 30% anti-freeze fluid and 70% deionized water, which can resist freezing down to minus 20 degrees Celsius.

Here are the antifreeze mixture ratios for different temperatures

Klein antifreeze ratio

If it is not possible to purchase a specialized brand of antifreeze, you can temporarily use Shell OAT-45°C large bottle automotive antifreeze. Based on the provided Shell OAT-45°C antifreeze ratios, here are the ratios for different ambient temperatures:

Mixture ratios

Shell OAT-45'C antifreeze ratio

Antifreeze fluid mixing and usage steps:

1. Power off all equipment.
2. Close the valve of the chiller unit and open the drain valve to empty the water from the water tank.
3. Clean the water tank with clean water and drain it.
4. Remove and clean the filter screen, filter element. and filter element at the inlet of the laser cooling water, then reinstall them.
5. Pour a measured amount of deionized water and a proportional amount of antifreeze fluid into the same container and mix them in the same direction until fully blended.
6. Open the valve of the chiller unit and inject the well-mixed antifreeze fluid into the chiller unit. Stop filling when the liquid level reaches the standard scale.

(Directly adding antifreeze fluid to the chiller unit is strictly prohibited as it will not fully dissolve in water and may generate flocculent substances, blocking the filter screen and filter element.)

Notes: If the equipment is shut down for a long time, such as during the Spring Festival or before laser transportation, it is necessary to drain the cooling water inside the equipment and use compressed air to blow out the remaining water in both the laser and chiller unit to prevent internal freezing and device damage.(The pipeline should also be blown clean.)
No antifreeze fluid can completely replace deionized water, and it cannot be used continuously throughout the year. After winter, the pipelines, especially the filter screen, filter element of the chiller unit, and the filter element at the inlet of the laser cooling water, must be cleaned with deionized water or distilled water. and deionized water or distilled water should be used as the coolant.

If conditions permit, we recommend improving the electrical environment, keeping the chiller unit running continuously, or upgrading the cooling water circuit design to simplify and speed up the daily process of draining the cooling water.