Does the Laser cutting water chiller need to do anti-freezing work?

Chiller is one of the important components of fiber laser cutting machine and Fiber Laser welding machine. The antifreeze work of the chiller should be done well.Ande Laser will often carry out antifreeze work every day.

Why does the chiller need to be antifreeze work?

If the ambient temperature is too low, it may cause the circulating cooling water pipeline to freeze, and the density of ice is lower than that of water, and the volume will expand when it freezes. Therefore, the cooling water pipeline inside the chiller and the laser may be caused by volume expansion. The road is broken or deformed, resulting in damage, so users are especially reminded to do the relevant anti-freezing work.

Reasonably adding antifreeze is the key to antifreeze

The full name of antifreeze is antifreeze coolant, that is, coolant with antifreeze function, which can prevent the coolant from freezing in cold winter, bursting the pipelines inside the laser and the chiller and damaging the tightness of the pipeline.

There are various types of antifreezes with different formulas on the market, so many customers don't know how to choose, mix, or have already selected some antifreezes that are not suitable for our chillers.

In fact, Ande Laser Intelligent Equipment chillers have certain requirements for antifreeze. Wrong selection or improper use will damage the internal pipelines of the equipment. The chillers have the following 5 requirements for the performance of antifreeze:
1.Good antifreeze performance .
2.Stable chemical performance
3.Anti-corrosion and anti-rust properties
4.The low temperature viscosity is not too big
5.No swelling and corrosive performance to rubber sealed conduit

Comparison of advantages and disadvantages of common antifreezes on the market:

Most of the water-based antifreezes used at home and abroad are ethylene glycol and propylene glycol. This type of antifreeze can be directly used in an appropriate proportion according to the environmental temperature requirements.

The antifreeze mother liquor, that is, the concentrated type, generally cannot be used directly, but should be adjusted to a certain concentration with demineralized water according to the requirements of the use temperature. Below we introduce two commonly used antifreezes on the market. (Due to the flammability of ethanol, customers are not recommended to add alcohol to the chiller, but to use antifreeze.)

Ethylene glycol concentration ratio table

The freezing point of ethylene glycol antifreeze changes with the change of ethylene glycol in the aqueous solution. When the volume concentration is below 56%, the ethylene glycol concentration in the aqueous solution will increase and the freezing point will decrease, but when the volume concentration is greater than 56%, As the concentration of ethylene glycol increases, the freezing point will rise, until the concentration is 100%, the freezing point rises to -13℃. This is also an important reason why concentrated antifreeze cannot be added directly to the chiller for antifreeze.

Give two examples from the table above:

1. In areas where the lowest temperature is -3.5℃, ethylene glycol antifreeze with a volume concentration of 9.1% can be used, and the ratio can be adjusted to approximately 1:9 [10% ethylene glycol, 90% pure water]

2. In areas where the lowest temperature is -15℃, ethylene glycol antifreeze with a volume concentration of 28% can be used, and the ratio can be adjusted to approximately 3:7 [30% ethylene glycol, 70% pure water]

PS: Some types of laser source have certain requirements for antifreeze. It is recommended to consult the laser manufacturer before adding antifreeze.

Propylene glycol concentration ratio table

The selection principles of propylene glycol water-based antifreeze and glycol water-based antifreeze are the same.

The following is still the focus.

Take notes!

Three important principles that need to be paid attention to during the use of antifreeze:

•The lower the concentration, the better

Most antifreeze is corrosive, and ethylene glycol with a concentration of more than 30% may cause the performance of certain types of lasers to decrease, and there is a risk of potential failure of the mechanical seal of the stainless steel pump motor. Therefore, in the case of meeting the antifreeze performance, the lower the concentration, the better.

•The shorter the use time, the better

The antifreeze will deteriorate to a certain extent when it is used for a long time. After the antifreeze deteriorates, it is more corrosive and the viscosity will also change, so it needs to be replaced regularly. The frequency of replacement is to change the water once every 2-3 months (at room temperature). When the ambient temperature starts to rise and the sub-zero temperature is lifted, the circulating cooling water can be replaced with softened water such as distilled water or purified water.

• Not to mixing

Try to use the same brand of antifreeze. Even if the main components of different types of antifreeze are the same, their additive formulas will be different. They should not be mixed to avoid chemical reactions, precipitation or bubbles.

Finally, we provide the following suggestions for the storage of the chiller when the equipment is not working in the cold winter:

1. If the equipment is shut down for a short period, it is recommended to start the chiller separately and let it run continuously to maintain the normal working water temperature. And always pay attention to the running status of the chiller to prevent power failure.

2. If the equipment does not work at night, and if it is determined that the power will not be cut off, please start the chiller separately. For energy saving considerations, set the water temperature of the low temperature system and high temperature system of for the optical fiber model to 5~10℃ (The same goes for chillers of single temperature). Ensure that the coolant is in a circulating state and the water temperature is not lower than the freezing point.

3. If the machine is shut down for a long time, be sure to drain the coolant inside the chiller, and drain the coolant inside the water tank, heating rod housing, water pump, filter, and heat exchanger with nitrogen. (If the coolant cannot be discharged due to environmental constraints, please refer to step 2 to ensure that the coolant is in a circulating state and the water temperature is not lower than the freezing point)

PS: If the chiller that drains the water is started for the first time after adding water, the air in the pipe may cause a water flow alarm by a low flow rate and then. If this happens, please make the water circulation through the exhaust hole of the water pump, or restart the pump several times at intervals of 10-20 seconds.