KR102207797B1 - Nitrogen generation system for laser equipment - Google Patents

Abstract

The present invention relates to a nitrogen generation system providing high-purity nitrogen consumed in a laser apparatus. Particularly, the present invention provides a high-purity nitrogen generation system for a laser apparatus, including: a water adsorbing unit configured to adsorb/remove water from the air supplied thereto with an adsorptive air dryer to produce dry air at -40°C or lower; a nitrogen generating unit configured to apply the dry air to a PSA module to generate nitrogen gas; a high-purity processing unit configured to introduce high-pressure hydrogen to the nitrogen gas in a reactor and to carry out reaction with the residual oxygen to produce water and to remove the thus produced water with a water adsorbing device; a compressing unit configured to increase the pressure of the nitrogen subjected to high-purity processing to a level of pressure required for a specific use; a storing and evaluating unit configured to store the pressure-increased nitrogen gas in a storage tank and to carry out reprocessing by resending the nitrogen gas to the reactor, when the purity measured from the stored nitrogen gas is lower than a reference purity value or the measured dew point exceeds a reference dew point value; and a controlling unit linked to the water-adsorbing unit to the storing and evaluating unit to monitor the air treatment process and configured to control the operating elements.

Description

High purity nitrogen generation system for laser equipment {Nitrogen generation system for laser equipment}

The present invention relates to a nitrogen generation system that provides high purity nitrogen for consumption in laser equipment.

Nitrogen gas with stable physical properties is used as an assist gas that blocks oxygen in laser processing to protect the heating area or prevents color change of the cut surface due to chemical degeneration of the cut area.

One of supplying high-purity nitrogen gas is to liquefy and purify the atmosphere to separate and collect liquefied oxygen and liquefied nitrogen, and then provide liquefied nitrogen to a pressure tank. This method has the advantage of providing high-quality, high-purity nitrogen, but has an uneconomic disadvantage in that it has equipment for maintaining cooling conditions and must operate it.

As another method, there is a method of trapping nitrogen in the atmosphere through a membrane, but since the amount of nitrogen generated is limited and the purity is low, it is not suitable for metal processing fields that require high purity.

The PSA device is a method of collecting a target gas by installing a plurality of pressurized tanks filled with an adsorbent (CMS, etc.) that adsorbs the intended gas, and sequentially repeating steps such as pressurization, decompression, and purification. Nitrogen that is removed by adsorption and the like, and does not adsorb, increases the purity.

The PSA method according to the prior art generates higher purity nitrogen than the membrane method, but remains at a level that is somewhat insufficient for use in high power laser equipment. Particularly, when used in laser equipment, there is a difference in quality that is sensitive even to a small amount of moisture, but the PSA method according to the prior art has a disadvantage in that the moisture management is not sufficiently low.

Korean Patent Registration No. 10-0856912 (2008.08.29)

An object of the present invention is to provide a nitrogen generation system capable of continuously supplying high-purity, low-moisture nitrogen to laser equipment.

In addition, detailed objects of the present invention will be clearly understood and understood by experts or researchers in this technical field through specific contents described below.

In order to solve the above problems, the present invention is an embodiment, a moisture adsorption unit that generates dry air with a dew point of -40 degrees Celsius or less by absorbing and removing moisture from the supplied air in an adsorption type air dryer, and transferring the dry air to the PSA module. A nitrogen generator that generates nitrogen gas by applying it, a high-purity treatment part that injects high-pressure hydrogen into the nitrogen gas in a reactor and reacts with residual oxygen to generate water, and removes the water with a moisture adsorber, and a high-purity treated nitrogen gas is used. A compression unit that pressurizes to a pressure level required for the reactor, and stores the elevated nitrogen gas in a storage tank, and when the purity measured in the stored nitrogen gas is less than the purity reference value or the measured dew point exceeds the dew point reference value, the reactor A high-purity nitrogen generation system for laser equipment comprising a storage and evaluation unit returning to and performing reprocessing, and a control unit connected to the moisture adsorption unit or the storage and evaluation unit to monitor the air treatment process and control operating elements. present.

Meanwhile, in the storage and evaluation unit, the purity reference value may be 99.999%, and the dew point reference value may be set to -75 degrees Celsius.

On the other hand, when the dew point of the dry air generated by the moisture adsorption unit exceeds -40 degrees Celsius, it is discharged to the atmosphere, and when it is less than -40 degrees Celsius, a primary evaluation unit that supplies to the nitrogen generator may be included.

Further, the purity and dew point of the nitrogen gas generated in the nitrogen generator is measured, and when the purity is less than 99.9% or the dew point exceeds -65 degrees Celsius, it is released into the atmosphere, and the purity is 99.9% or more and the dew point is- In the case of 65 degrees or less, a secondary evaluation unit supplied to the high purity processing unit may be included.

On the other hand, the control unit may increase or decrease the amount of hydrogen gas injected into the reactor according to the amount of nitrogen required by the user, and control the operation of the compression unit to increase or decrease the nitrogen discharge flow rate.

According to an exemplary embodiment of the present invention, when the purity or dew point of the nitrogen gas stored in the storage tank does not reach a certain level, it is returned to the high-purity processing unit to perform reprocessing, thereby generating high-quality nitrogen gas.

In addition, the first evaluation unit and the second evaluation unit determine the physical properties of the intermediate product and, if it does not meet a certain standard, discharge it to the outside, thereby preventing degradation of materials such as adsorbents and preventing damage. It also helps to ensure that nitrogen gas of the desired quality is produced.

Other effects of the present invention will be clearly understood and understood by experts or researchers in this technical field during the process of carrying out the present invention or through the detailed contents described below.

1 is a view schematically showing the configuration of the first half of a high purity nitrogen generation system for laser equipment according to an embodiment of the present invention.
2 is a view showing the configuration of the second half of the embodiment shown in FIG.

Hereinafter, the configuration, function and operation of the high purity nitrogen generation system for laser equipment according to the present invention will be described with reference to the accompanying drawings. However, reference numbers for the same or similar components throughout the drawings will be used unified.

In addition, in the following description, terms such as'first' and'second' are used to distinguish constituent elements having the same technical meaning for convenience. That is, any one configuration may be arbitrarily named as'first configuration' or'second configuration'.

The accompanying drawings show an applied embodiment of the present invention, and the technical idea of the present invention should not be limitedly interpreted through the accompanying drawings. If it can be construed that some or all of the figures are not necessarily required for the implementation of the invention from the perspective of an expert belonging to this technical field, this does not limit the invention described in the claims.

In addition, in describing the content of the invention, the unit of all temperature expressions is Celsius.

1 and 2 are related to a schematic configuration of a high-purity nitrogen generation system for laser equipment according to an embodiment of the present invention.

The nitrogen gas supplied to the arrest gas of the laser equipment should be able to supply a sufficient amount while maintaining the dew point as low as possible to prevent damage to the laser equipment or discoloration of the cut surface.

For example, nitrogen gas supplied to laser equipment can have a dew point of -75 degrees or less at a purity of 99.999% or higher. In addition, it must be able to provide 250 N㎥/h or 300 N㎥/h level depending on the operating conditions of the laser equipment.

In order to satisfy these conditions, the high purity nitrogen generation system according to the embodiment of the present invention includes a moisture adsorption unit 10, a nitrogen generation unit 20, a high purity processing unit 30, a compression unit 40, a storage and evaluation unit ( 50) and a control unit (not shown).

The moisture adsorption unit 10 generates dry air with a dew point of -40 degrees or less by removing moisture through the adsorption-type air dryer 16 by inhaling compressed air in the atmosphere.

Specifically, air is sucked and compressed through the compression pump 11, and it is temporarily stored in the storage tank 12. The stored air passes through the moisture filter means 13, the oil filter means 14 and the cooler 15 to filter out foreign matter and lowers the temperature raised by compression. Here, the filter means for pre-treating the stored air may be changed according to the design of the system.

After that, the compressed air is firstly removed while passing through the adsorption air dryer 16.

Here, the adsorption air dryer 16 is a device operated by the PSA method, and a pair of tanks are alternately adsorbed and regenerated. Alumina, silica gel, or the like may be used as an adsorbent for adsorbing moisture. The operation method and detailed configuration in which a pair of tanks adsorb and regenerate once and remove a target object may be the same as those of known PSA-related technical details.

Passing through the adsorption air dryer 16, compressed air is generated as dry air with a dew point of -40 degrees or less.

As an additional configuration, a primary evaluation unit 60 is provided between the moisture adsorption unit 10 and the nitrogen generation unit 20 to check the condition of the dry air and discharge it to the outside when it is not suitable for the nitrogen generation unit. do.

Specifically, the primary evaluation unit 60 is provided with a measuring means 61 for measuring the dew point of the dry air emitted from the air dryer, and the control unit discharges it to the atmosphere when the measured dew point exceeds -40 degrees. Operate valve 62 Here, a known dew point measurement sensor may be used as the measuring means 61, and the valve 62 may be an electronic three-way valve.

On the other hand, when the measured dew point is confirmed to be -40 degrees or less, the control unit switches the flow direction through the valve to supply dry air to the nitrogen generator 20.

More preferably, the reference value of the dew point for evaluating the integrity of the dry air at the outlet side of the air dryer 16 may be set to -45 degrees.

The lower the outlet-side dew point, the higher purity nitrogen gas can be produced in the nitrogen generator 20 afterwards, and the service life of the nitrogen generator 20 can also be increased. However, since the operating conditions of the air dryer 16 for significantly lowering the outlet side dew point are difficult and costly, it becomes uneconomical, so the reference value of the outlet side dew point can be set to about -45 degrees.

On the other hand, when the outlet side dew point exceeds -40 degrees, it is difficult to generate nitrogen gas with sufficient purity in the nitrogen generator afterwards, and the amount of nitrogen gas generated is also reduced. In addition, there is a disadvantage that the life of the CMS adsorbent filling the adsorption tower is greatly shortened because the amount of moisture to be treated is too large.

Therefore, if it is determined that the outlet side dew point exceeds -40 degrees, it is considered that it is practically difficult to finally secure the intended level of purity, and the dry air is discharged to the outside.

Referring to FIG. 2, dry air having a dew point of -40 degrees or less is provided to the nitrogen generator 20 and is generated as nitrogen gas in the PSA module 21.

Here, the PSA module 21 uses a pair of adsorption towers equipped with CMS for adsorbing oxygen, and the steps of capturing oxygen by pressure from one side and regenerating by depressurizing and purging are repeatedly performed, and nitrogen It is to increase the purity of. The detailed configuration and operation of the PSA module may be the same as known.

Although not shown, a positive pressure regulator valve may be installed in front of the PSA module in order to protect the CMS adsorbent while operating the operating pressure in the tank at a maximum level of 8.5 ㎠/kg.

As an additional configuration, the nitrogen generating unit 20 is provided with a secondary evaluation unit 70.

The secondary evaluation unit 70 includes a measuring means 71 for measuring the purity and dew point of the nitrogen gas generated by the nitrogen generating unit 20, and a valve 72 for discharging the nitrogen gas into the atmosphere when it is found to be unsuitable. Includes. Although the measuring means 71 is shown in one configuration in the drawing, a sensor measuring purity and a sensor measuring dew point may be installed respectively. In addition, the valve 71 may be an electronic three-way valve that changes the flow direction of nitrogen gas.

When the purity of the nitrogen gas passing through the nitrogen generating unit 20 is less than 99.9% or the dew point exceeds -65 degrees, the secondary evaluation unit 70 determines that the nitrogen gas is inappropriate and discharges it into the atmosphere. will be. Here, the control unit is involved in the evaluation of the purity and the measured value of the dew point and the operation of the valve.

When the purity of the nitrogen gas generated by the nitrogen generating unit 20 is less than 99.9%, it is practically difficult to generate the final purity of the nitrogen gas to the level of 99.999% even if the purity of the nitrogen gas is performed below the high-purity processing unit 30 with such nitrogen gas. there is a problem.

In addition, in order to lower the dew point of the finally stored nitrogen gas to a level of -75 degrees, the dew point in the line of the nitrogen generator 20 needs to be managed to be -65 degrees or less.

Therefore, if the purity and dew point do not satisfy a certain standard value, nitrogen gas is released into the atmosphere, and measures are taken to prevent it from flowing into the high-purity processing unit.

On the other hand, when the purity of the nitrogen gas is 99.9% or more and the dew point is -65 degrees or less, it is assumed that a suitable nitrogen gas is generated, and the nitrogen gas is supplied to the high-purity processing unit 30 to be described later.

The high-purity processing unit 30 includes a hydrogen injection means 32 for quantitatively supplying high-pressure hydrogen, and a reactor that reacts the supplied high-pressure hydrogen (H2) with oxygen (O2) gas remaining in the nitrogen gas to change it into moisture (H2O). 31) and a moisture absorber 33 for collecting and removing moisture generated in the reactor 31.

Here, the hydrogen gas is a pressure of 8.5 cm2/kg level equivalent to the outlet pressure of the nitrogen generator, and the purity of 99.99% or more may be used.

The hydrogen injection means 32 includes a hydrogen storage tank, a flow control valve, and an electromagnetic flow meter. According to the amount of nitrogen gas generated according to the operating conditions of the laser equipment, the control unit precisely controls the injection amount of hydrogen gas through an electromagnetic flow meter and a flow control valve.

For example, when nitrogen gas is consumed at 250 Nm 3 per hour in the laser equipment, the control unit may operate and control the hydrogen injection means 32 so that 10 NL of hydrogen gas per minute is injected into the reactor.

The reactor 31 is provided with a catalyst for accelerating the bonding reaction of hydrogen and oxygen, and a temperature control means for improving the bonding activity. Here, the detailed configuration, such as a catalyst and a temperature control means, may be the same as known.

The moisture adsorber 33 is for removing moisture generated through the reactor, and may be adopted in substantially the same configuration as the adsorption air dryer (16 in FIG. 1) of the moisture adsorption unit described above.

The compression unit 40 is to increase the pressure level of the nitrogen gas treated with high purity to a pressure level required by the place of use. Here, the use place is laser equipment, and the required pressure level may be 40 cm2/kg.

The compression unit 40 includes a compression pump device 41 configured by connecting a plurality of piston boosters in parallel, and filters 42, 43 and 44 for removing oil remaining in the elevated nitrogen gas.

The operation level of the compression pump device 41 is adjusted by a control unit according to the nitrogen gas demand of the user. For example, the control unit generates nitrogen gas at a pressure of 40 ㎠/kg at a level of 250 N㎥ per hour or a nitrogen gas at a pressure of 40 ㎠/kg at a level of 300 N㎥ per hour according to the setting of the laser equipment. Control the operation of

In the nitrogen gas boosted by the compression pump device 41, oil, moisture, foreign substances, and the like are easily mixed during the mechanical compression process. An oil separation filter 42, a water separation filter 43, a particle filter 44, etc. are installed at the rear end of the compression pump device to remove these foreign substances.

Furthermore, a cooling means 45 for lowering the temperature of the nitrogen gas to room temperature allowance may be further provided. The cooling means 45 is for lowering the temperature of the nitrogen gas to the room temperature level, and the detailed configuration and operation method may be the same as known.

If the nitrogen generating system is installed in a location advantageous for cooling, or if natural cooling is possible by providing a pipe line extending sufficiently long from the compression unit, the cooling means 45 may be omitted.

Although each piston booster of the compression pump device 41 is provided with a separate cooler, the temperature of the nitrogen gas at the output side of the compression pump reaches 60 to 70 degrees. After that, even though cooling proceeds while passing through the oil separation filter 42 and the moisture release filter 43, it is still about the level of about 30 degrees. The cooling means 45 can be used as an active means to lower the temperature of the nitrogen gas to a level suitable for storage.

Meanwhile, the storage and evaluation unit 50 stores nitrogen gas and finally evaluates whether the stored nitrogen gas is suitable to be provided to the laser equipment.

The boosted nitrogen gas is stored in the storage tank 51. The pressure of the nitrogen gas in the storage tank 51 may be 40 cm2/kg, and the temperature may be 15 degrees.

The storage tank 51 is provided with a measuring means 52 for measuring the purity and dew point of the nitrogen gas, and the measuring means is connected to the control unit.

When the measured purity is less than the purity reference value or the measured dew point exceeds the dew point reference value, the control unit performs reprocessing by returning nitrogen gas to the reactor 31 of the high purity processing unit 30.

A recovery line 53 for recovering nitrogen gas stored in the storage tank 51 to the reactor is provided. The recovery line is provided with a valve 531 that opens and closes, and a positive pressure valve 532 that controls the pressure of nitrogen gas to a level suitable for the reactor.

The nitrogen gas returned to the reactor 31 is improved in purity and dew point in the high purity processing unit 30, and is then stored and evaluated in a storage tank through the compression unit 40 again.

Here, the purity reference value for determining whether to return nitrogen gas in the storage tank to the reactor is 99.999%, and the dew point reference value may be -75 degrees Celsius.

By supplying the assist gas with nitrogen gas that satisfies the purity standard value of 99.999% or less and the dew point standard value of -75 degrees or less, the laser equipment can be completely protected and the color change of the cut surface can be reliably prevented.

The control unit is connected to various measurement equipment, valves, pumps, etc. of the moisture adsorption unit or the storage and evaluation unit to monitor the overall air treatment process and operate and control the valves according to a preset control algorithm. Such a control unit includes an electronic device as known in the art such as an operation processing device, a recording device, and a power management module.

The control unit is involved in the operation of the first and second evaluation units, receives and stores the evaluation reference values from each unit, compares the measured physical properties and the reference values to determine whether to perform the treatment according to the next step or discharge to the atmosphere, and accordingly It sends out a control signal that activates the valve.

In addition, the control unit increases or decreases the amount of hydrogen gas injected into the reactor according to the nitrogen demand of the user, and controls the operation of the compression unit to increase or decrease the nitrogen discharge flow rate.

Although not shown, it is possible to detect the flow rate moving from the storage tank to the laser equipment, and calculate the nitrogen demand of the user based on this flow rate. Accordingly, the operation level of the compression unit is determined, and the amount of hydrogen gas injected into the reactor is determined accordingly, and each valve is operated and controlled.

On the other hand, laser equipment is pre-set in several operating modes, and the nitrogen requirement for each mode can be predetermined. Meanwhile, the control unit stores the amount of hydrogen gas injected into the reactor for each mode of the laser equipment and the operation level of the compression unit in advance.

Thereafter, when the mode is changed in the laser device, the control unit receives information on the currently selected mode from the laser device, and controls the hydrogen injection means and the compression pump at a predetermined level for each mode.

The high-purity nitrogen generation system for laser equipment according to an embodiment of the present invention can greatly improve the quality of so-called oxidation-free cutting of laser equipment by providing high-purity nitrogen gas.

By releasing and removing the processing gas that is below the level in the first and second evaluation units, it is possible to prevent damage to expensive materials such as adsorbents and reactors.

In addition, the first evaluation unit and the second evaluation unit control the system to reach the target value by evaluating the physical properties of intermediate products required for the final nitrogen gas to reach the target dew point and purity.

10: moisture adsorption unit
11: compression pump 12: storage tank 13: water filter means
14: oil filter means 15: cooler 16: air dryer
20: nitrogen generator
21: PSA module
30: high purity processing unit
31: reactor 32: hydrogen injection means 33: moisture adsorber
40: compression unit
41: compression pump device 42: oil separation filter
43: water separation filter 44: particle filter 45: cooling means
50: storage and evaluation unit
51: storage tank 52: measuring means
53: recovery line 531: valve 532: positive pressure valve
60: 1st evaluation unit
61: measuring means 62: valve
70: 2nd evaluation unit
71: measuring means 72: valve

Claims (5)

A moisture adsorption unit that generates dry air with a dew point of -40 degrees Celsius or less by absorbing and removing the supplied air from the adsorption-type air dryer.
A nitrogen generator for generating nitrogen gas by applying the dry air to the PSA module,
When the dew point of the dry air generated in the moisture adsorption unit exceeds -40 degrees Celsius, it is discharged to the atmosphere, and when it is less than -40 degrees Celsius, the primary evaluation unit supplies it to the nitrogen generation unit,
A high-purity treatment unit for introducing high-pressure hydrogen into the nitrogen gas in a reactor and reacting with residual oxygen to generate water, and removing the water with a moisture adsorber,
The purity and dew point of the nitrogen gas generated in the nitrogen generator is measured, and if the purity is less than 99.9% or the dew point exceeds -65 degrees Celsius, it is discharged into the atmosphere, and the purity is 99.9% or more and the dew point is -65 degrees Celsius. If the degree is less than the secondary evaluation unit to be supplied to the high purity processing unit,
A compression section that boosts high-purity treated nitrogen gas to the pressure level required by the user,
When the elevated nitrogen gas is stored in a storage tank, and the purity measured in the stored nitrogen gas is less than 99.999% or the measured dew point exceeds -75 degrees Celsius, it is returned to the reactor to perform reprocessing. Evaluation Department and
And a control unit connected to the moisture adsorption unit to the storage and evaluation unit to monitor the air treatment process and to control an operation element.
High purity nitrogen generation system for laser equipment.
delete delete delete In claim 1,
The control unit
According to the nitrogen requirement of the application
Increasing or decreasing the amount of hydrogen gas injected into the reactor,
Characterized in that controlling the operation of the compression unit to increase or decrease the nitrogen discharge flow rate
High purity nitrogen generation system for laser equipment.

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