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Co2 laser tube inflation technology
The design life of the Co2 Laser laser is 20,000 hours. When the laser reaches its lifespan, it can be reused for 20,000 hours only by refilling (replacing the resonator gas). Repeated inflation can significantly extend the life of the laser.
Co2 laser tube gas or cavity gas is easily transported. CO2, nitrogen and helium are supplied through high pressure cylinders at 2200 PSIG (pounds per square inch, gauge). This gas supply method is cost-effective and convenient, due to the low consumption rate of the resonant cavity gas. For each gas, the pressure flowing into the laser cavity was 80 PSIG and the flow rate ranged from 0.005 to 0.70 scfh (norm cubic feet per hour).

In fact, by specifying the purity level of the gas, it was found that three main pollution needs were reduced: hydrocarbons, humidity and particulate matter. The hydrocarbon content must be limited to 1 part per million, the humidity must be less than 5 parts per million, and the particles must be less than 10 microns. The presence of these types of contamination can result in severe loss of beam power. And they can also leave deposits or corrosion spots on the mirrors of the resonant cavity, which reduces the effectiveness of the mirrors and shortens their useful life.

For laser gas, one hydraulic cylinder is used as the primary gas supply source, and the other hydraulic cylinder is used as the backup gas supply source. Once the hydraulic cylinder as the primary air supply source is empty, the hydraulic cylinder as the backup air supply source is switched over to supply air, which prevents the laser from being actively shut off when the primary air supply source runs out of gas. The terminal control panel has a three-way controller that can fine-tune the inlet pressure at the laser inlet. For conditioning equipment, the leak rate of helium is about 1X 10-8 scc/s (standard cubic centimeter/second, after conversion, the leak rate of helium is about 1 cubic centimeter/3.3 years). Stainless steel pipes and pipe

tightening equipment are used to maintain high gas purity. The conversion equipment also incorporates a T-strainer that removes any contaminants entering the pipeline, which may come from the initial construction stage, or when replacing the hydraulic cylinder, or any leaks that may have appeared in the pipeline. As the gas enters the laser, a 2-micron filter and a high-flow safety valve provide final protection to prevent particle contamination or the appearance of overpressure conditions.
Nitrogen can be used for auxiliary cutting of carbon steel, stainless steel, and aluminum materials. The cutting speed of carbon steel obtained with nitrogen is lower than that obtained with oxygen. However, using nitrogen will prevent oxide build-up on the cut surface. With nitrogen, nozzle sizes range from 1.0 mm to 2.3 mm, pressures at the nozzles can reach up to 265 PSIG, and flow rates can reach 1800 scfh. TRUMPF recommends a nitrogen purity of at least 99.996% or class 4.6. Similarly, if the gas purity is higher, the resulting cutting speed will be higher and the cutting will be cleaner. All auxiliary gas-related equipment must also be specially designed to maintain high gas purity.
The higher flow rate of the auxiliary gas makes the hydraulic cylinder or dewar a more cost-effective source of air than the high pressure cylinder. Since what is stored is a liquid substance at low temperature, the transpired gas is stored in the headspace. Common hydraulic cylinders have different types of safety valves with air pressures of 230, 350 or 500 PSI. Typically, hydraulic cylinders with a pressure of 500 PSI (aka laser cylinders) are the only suitable type due to the high pressure requirements of the laser assist gas. Substances can be in gaseous or liquid form when extracted from hydraulic cylinders. However, only gaseous substances can pass through the laser and laser conditioning equipment. If liquefied gas is used, then the liquefied gas must be vaporized by an external vaporizer before it can be used.

It should be pointed out that the process of extracting gas from a hydraulic cylinder can be quite complicated. The maximum rate of gas extraction from a single Dewar cylinder is approximately 350 cubic feet per hour, with successive applications, the extraction rate will continue to decrease as the capacity of the hydraulic cylinder begins to decrease. The use of multi-pipe equipment in different hydraulic cylinders does not always have a positive effect. Since the velocities obtained from the top pressures of different cylinders will not be equal, the airflow in the cylinder with the stronger pressure may block the airflow from the cylinder with the lower pressure. With multi-pipe equipment, only 20% of the original dewar flow rate (ie, 70 cubic feet per hour) is added for each hydraulic cylinder added. In order to improve the air flow of the hydraulic cylinder multi-pipe equipment, it is also necessary to install a multi-pipe valve. The multi-pipe valve can make the air pressure at the top of each hydraulic cylinder more uniform, and then make the extraction process of the gas in the different hydraulic cylinders more uniform. When using a multi-pipe valve, each additional hydraulic cylinder can add approximately 80% of the original dewar flow (ie, 280 cubic feet per hour).
Regarding the status of oxygen and nitrogen as auxiliary gases, in the future, the company expects the gas supply method of nitrogen to become solid tanks. Since the oxygen requirements are not very high, only up to 50 PSI and 250 scfh, this can be connected to a dome-pressurized, balance-bar-style conditioner via two hydraulic cylinders using a manifold. The balance bar design enables flow rates of up to 10,000 cubic feet per hour per hour with a small pressure drop of between 30-40 PSI. Traditional reverse seat conditioners are not suitable for this application due to their severe drop in the airflow curve. As the flow rate requirements for the conditioners rose, the resulting pressure drop at the outlet became more severe. In this way, when the minimum pressure in the laser cannot be maintained, the maintenance circuit is triggered and the laser is actively closed.

The dome pressurization feature of the conditioner allows a small portion of the gas to be expelled from the primary conditioner to the secondary conditioner, which returns the gas to the dome of the primary conditioner. Use these gases, rather than a spring, to hold down the diaphragm to open the valve seat and allow downstream gas to pass. This planning allows the outlet pressure to vary between 0-100 PSI or 0-2000 PSI, and, although the inlet pressure fluctuates, the outlet flow rate and pressure remain constant.
It is not very useful to supply nitrogen in the same way that a hydraulic cylinder supplies gas. Since the maximum flow rate required is 1800 scfh and the pressure is 256 PSIG, this would require eight hydraulic cylinders to be manifolded together, and a manifold valve would have to be used to accomplish this task. However, suppose the liquid is drawn from two liquid tanks and fed into a finned vaporizer with a flow rate of 5000 scf. Nitrogen flowing from the gasifier is fed to a dome-pressurized, balance-bar conditioner similar to that found in an oxygen supply.