Winter is coming. For the cold weather in winter, we need to master the antifreeze skills of the relevant fiber laser cutting machine. Here I will make a related introduction for you. We must pay attention to the following three aspects:
1. Since water is used as the cooling medium for the laser cutting machine, the operating ambient temperature of the laser should be above 5 ℃.
2. In winter, if there is no heating in the workshop, or the ambient temperature may be lower than 5 ℃. If the laser does not work at night or on weekends, the machine tool can still be turned on. In this way, the cooling water is still circulating and will not freeze.
3. If your factory or workshop has a long holiday during the festival and the machine tool does not run. Be sure to pay attention to the heat preservation treatment of the machine tool in winter. Be sure to drain the water from the chiller, laser, cutting head, lens and so on to prevent the machine tool from being damaged by ice.
At the same time, we should also take anti freezing measures for fiber laser cutting machine in time during the cold wave! Qingyuan laser provides you with some technical information and solutions on antifreeze:
1、 Basic principle and method of antifreeze
All liquids have a "freezing point". When the temperature of the liquid is lower than this "freezing point", it will solidify and form a solid, while the volume of deionized water or purified water will become larger during the solidification process, which will "prop up" the pipes and seal connections of the water cooling system and cause damage. In order to avoid damage to the laser, output head and water cooler caused by solidification of cooling liquid, there are three solutions:
Scheme 1: if there is absolutely no power failure in the local area, do not turn off the water cooler at night to ensure that the coolant is in a circulating state and the temperature is not lower than the freezing point.
Scheme 2: drain the cooling liquid in the laser, laser output head and water cooler after use every day.
Scheme 3: use antifreeze as coolant.
2、 Cooling water emptying method and pipeline design scheme are as follows:
Open the drain valve of the chiller and drain all the water. Take out the filter element for drainage, because this part of water cannot be discharged, so as to prevent the shell from being broken by ice. Some water that is not easy to be discharged needs to be blown away with compressed air to prevent water from flowing back into the laser and damaging the precision sensor inside the laser. All water valves must be closed. In the following schematic diagram, except for the water tank laser, all valves need to be purchased and installed by the customer. If you need guidance, you can call Qingyuan 400-000-9276.
1. Schematic diagram of waterway connection:
2. Valve status during normal operation (red off and yellow on):
3. Before shutdown, use the water cooler to actively evacuate:
When the water cooler is turned on, close the red valve and open the Yellow valve. At this time, the water cooler will actively pump the water from the internal water tank into the water storage bucket until there is no large amount of water flowing out, and close the power supply of the water cooler.
4. Vent idle water with low-pressure air:
Close the red marked valve according to the requirements of the figure, open the Yellow marked valve, and inject clean compressed air or nitrogen not higher than 0.4MPa (within 4kg) into point a until there is no water at the outlet of point B.
5. Water cooler drain normally open
Finally, turn over the drain of the water cooler to drain the remaining water in the final water tank.
Note: all cooling water in the laser, laser output surface, foreman and water cooler must be discharged cleanly before the complete set of water cooling pipes and related devices can be effectively maintained!
3、 Use antifreeze to prevent freezing
When the operating environment is often powered off and the conditions for draining the coolant every day are not available, antifreeze must be used. The basic solution of antifreeze is generally composed of alcohols and water, which requires high boiling point and flash point, large specific heat and conduction ability, low low temperature viscosity, not easy to bubble, and not corrosive to metal parts, rubber hoses, etc. When selecting or mixing antifreeze, its freezing point should be 5 ℃ lower than the minimum temperature of the application environment.
1. Use ethanol for short-term antifreeze:
If the power is cut off and the cooling water cannot be emptied, temporary short-term antifreeze is required. Ethanol (alcohol) can be added to deionized or purified water, and the increase cannot exceed 40% of the volume of the water tank. Because ethanol is highly corrosive, it will corrode grease, paint, rubber parts, and metals, so it cannot be used for a long time. It must be emptied within a week and the cooling pipeline must be cleaned with purified or deionized water. If there are still antifreeze requirements, special antifreeze must be selected.
2. Use special antifreeze of professional brand:
Introduce and choose Clariant brand. There are two types of antifreeze suitable for laser system:
1) Antifrogen? N glycol water type
2) Antifrogen? L propylene glycol water type
Note: any antifreeze cannot completely replace deionized water and cannot be used for a long time all year round. After winter, the pipeline must be cleaned with deionized water or purified water, and the deionized water or purified water must be restored as the coolant.
If there are conditions, we still suggest to improve the electric environment, insist on keeping the water cooler on, or upgrade the cooling water circuit design, so that the cooling water can be drained simply and quickly every day.
The above is the relevant common sense that we should pay attention to in winter about the antifreeze skill operation of metal laser cutting machine. Only when we are familiar with the antifreeze skill operation, can we better maintain our own laser cutting equipment.