KR20100012768A - Flow meter - Google Patents
Flow meter Download PDFInfo
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- KR20100012768A KR20100012768A KR1020080074336A KR20080074336A KR20100012768A KR 20100012768 A KR20100012768 A KR 20100012768A KR 1020080074336 A KR1020080074336 A KR 1020080074336A KR 20080074336 A KR20080074336 A KR 20080074336A KR 20100012768 A KR20100012768 A KR 20100012768A
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- Prior art keywords
- welding
- gas
- pressure
- flow rate
- dynamic pressure
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D13/00—Component parts of indicators for measuring arrangements not specially adapted for a specific variable
- G01D13/02—Scales; Dials
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D21/00—Measuring or testing not otherwise provided for
- G01D21/02—Measuring two or more variables by means not covered by a single other subclass
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F19/00—Calibrated capacity measures for fluids or fluent solid material, e.g. measuring cups
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L7/00—Measuring the steady or quasi-steady pressure of a fluid or a fluent solid material by mechanical or fluid pressure-sensitive elements
- G01L7/18—Measuring the steady or quasi-steady pressure of a fluid or a fluent solid material by mechanical or fluid pressure-sensitive elements using liquid as the pressure-sensitive medium, e.g. liquid-column gauges
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Arc Welding In General (AREA)
Abstract
Description
The present invention precisely measures the fluid gas pressure during arc welding using CO2 welding, MAG welding, MIG welding, TIG welding, PLAZMA welding and other shielding gases such as hydrogen, helium, etc. to measure the amount of gas that can improve welding failure and productivity. It relates to a precision flowmeter for.
Float flowmeters are widely used in the field, and the flow rate fluctuates depending on the site's usage environment such as pressure change, humidity change, temperature change, and gas clogging, and there are difficulties in managing actual welding conditions.
Therefore, it is necessary to be able to correct the above various changes by using a precision flow meter managed by static pressure and dynamic pressure.
In the existing float type flow meter, the actual flow rate changes frequently depending on the site environment such as pressure, humidity, temperature, and volume change of the rubber hose, which causes unnecessary gas waste and welding defects.
The following is a kind of welding to which the present invention can be applied and a description thereof.
MIG welding, MAG welding, CO2 welding, and TIG welding can be said to be GMAW (metal gas welding method) included in the large category of arc welding (AW).
There are many different types of arc welding (AW), including shielded metal-arc welding (SMAW), gas tungsten arc welding (GTAW), or inert gas tungsten arc welding. Typical examples include welding; TIG, gas metal arc welding (GMAW), submerged arc welding (SAW), and plasma arc welding (PAW).
SMAW welding is a general arc welding (AC, DC electric welding) in the introduction of welding, GTAW = TIG welding can be understood as argon welding.
Although SMAW is effective for welding many ferrous metals, it is inadequate for welding aluminum, magnesium or other highly reactive metals, and at high temperatures to serve as a blanket to protect against ingress of oxygen or hydrogen in arc environments. The method of supplying and welding inert gas (Ar, He etc.) which does not react with a metal was introduced.
In addition, gas-metal arc welding using consumable electrodes instead of non-consumable tungsten electrodes has been developed, which feeds the torch at a constant rate to an electrode wire having a diameter of 1.0 to 2.4 mm of a spiral core instead of a tungsten electrode. It was developed for the purpose of welding thick conductive plates by welding by generating arc between wire and base metal, but it is currently applied to various fields such as aluminum, copper, magnesium, nickel alloy, titanium, steel alloy, etc.
GMAW (Gas metal arc welding method) is activated when (1) inert gas metal arc welding (metal inert gas, MIG) and (2) active gas are used. Active gas metal arc welding or metal active gas (MAG) or carbon dioxide (or CO2) welding.
Inert gas arc welding includes: ① gas tungsten arc welding (GTAW) or inert gas tungsten arc welding (TIG) using a non-consumable electrode tungsten rod; Gas metal arc welding (GMAW) using an uncovered metal electrode, which is a consumable electrode, may be distinguished.
In general, GTAW is used in thin and medium plates of 0.6-8mm, GMAW is used in thick plates (thick plates) of 6mm or more, and the latter is more efficient than the former.
In detail, GMAW welding is an automatic and semi-automatic welding method in which inert gas is used to prevent oxidation and nitriding of molten metal and to generate arc while continuously supplying electrode wire (welding rod) as a filler metal.
This welding method welds thick plates such as Al alloy, Mg alloy, STS steel, Cu alloy, low alloy steel, high tensile strength steel, which are impossible by arc welding or oxygen welding.
Ar (argon) and He (helium) are mainly used as the protective gas, and argon gas is mixed with oxygen or carbon dioxide gas.
The mixed gas (Ar * CO2, Ar * N2, Ar * O2, Ar * He) is called MAG welding (Metal Active Gas welding).
The GMAW welding method requires the supply of electrode wire continuously because the electrode is consumable. Therefore, they are a gas and cooling water supply device, a device for supplying a metal wire at a constant speed, a power supply device and an electrode wire, a control device for adjusting the supply speed of the current, gas and cooling water. The electrode wire is fed to the center of the welding torch of this apparatus and melts into the molten pool while forming an arc. Gases such as helium, argon, carbon dioxide, and nitrogen flow around the electrode. The components of the electrode wire are usually made of the same base material and are coated with copper to prevent electrical contact and rust. The electrode wire, which is a filler material, contains an antioxidant (oxidizer), which contains manganese, silicon, aluminum, nickel alloy fillers, titanium, silicon, and copper alloy fillers, titanium, silicon, and phosphorus. .
Among the inert gas metal arc welding methods, the MIG method generates arcs by continuously feeding electrode wires, which are filler metals, and has a higher welding rate than TIG. The power supply is direct current and works in reverse polarity with the wire as the anode. Pure Ar, Ar + He, Ar + O2, and Ar + CO2 are used as protective gases for MIG welding. Gun refers to the part used to transfer the electrode wire, welding current and protective gas from the wire feeder to the arc area. Inert gas metal arc welding has no slag to remove, resulting in a faster working cycle than coated arc welding.
CO2, that is, carbon dioxide arc welding, is a welding method that uses economical carbon dioxide instead of inert gas. The electrode mainly uses consumable (melt-type) and non-consumable electrode. Since carbonic acid gas is active, it is highly oxidizable at high temperature arcs, and oxidation of the deposited metal is severe, and pores and other defects are likely to occur. Therefore, wires containing deoxidizers such as Mn and Si are used. In addition to pure CO2 gas, CO2-O2, CO2-CO, CO2-Ar, CO2-Ar-O2, etc. may be used.
CO2 gas becomes 2CO2 ↔ CO + O2 at high temperature arc, so the shield atmosphere of carbon dioxide arc welding is mixed with CO2, CO, O2 and O gas. The reason why the deoxidizer is used is to prevent welding defects caused by the bubbles of CO.
① Carbon dioxide, a shield gas, is decomposed by high temperature arc heat.
CO2 ↔ CO + O
② The molten iron is oxidized in the above oxidizing atmosphere.
Fe + O ↔ FeO
③ The iron oxide is combined with the carbon contained in the steel to form carbon monoxide bubbles as follows.
FeO + C ↔Fe + CO ↑
④ However, if there are deoxidizers such as Mn and Si, the following reaction occurs and iron oxide in molten steel is reduced to suppress the generation of bubbles.
FeO + Mn ↔ MnO + Fe FeO + Si ↔ SiO2 + Fe
⑤ MnO, SiO2, etc., which are deoxidation products, form a slack due to the specific gravity difference with the deposited metal and float on the weld bead surface.
Carbon dioxide arc welding is not used for aluminum, magnesium, titanium, etc., because the atmosphere is oxidizing, because an oxide film is formed on the molten surface to prevent fusion.
The use of double flux-cored wire (composite wire) is made by adding deoxidizer and arc stabilizer such as Mn, Si, Ti, and Al to hollow wire. As the arc is stable, both DC and cheap AC can be used.
Union arc welding is a method of supplying a magnetic solvent to a carbon dioxide gas stream. When an arc is generated and an electric current flows through the wire, a magnetic field is formed around the wire, which causes the flux to be magnetized and the wire is magnetized. It is adsorbed in and acts as a coating seal. Therefore, this method is also called magnetic flux method. Flux causes slack.
In the case of the transition of alloying elements in the wire during pure carbon gas arc welding, the ratio of each component remaining is mild steel, where C is generally reduced in oxidation by 50-80%, Si is 30-60%, and Mn is 40-60%. Cr, Ni and Mo hardly decrease. However, only about 30% of Ti remains after oxidation reduction.
Plasma arc welding is a non-consumable electrode welding method that uses a contracted arc between an electrode and a molten pool or between an electrode and a shrinkage nozzle (non-directed arc). It is also used for metal spraying and cutting.
Principle of action PAW method is similar in many ways to GTAW, and the arc temperature rises because the same amount of current is carried when the electric arc between the tungsten electrode and the base material shrinks or decreases in cross section. This contracted arc is called Plasma.
The above is the contents of internet materials related to MIG welding, MAG welding, CO2 welding, and plasma welding.
[Protection Gas]
* CO2 gas: It is most used for welding by using economic carbon dioxide instead of inert gas.
Ar gas: Heavier than He. That is, because the gas does not go down, the shielding effect can be seen with a small flow rate. In the above welding, the gas flow rate must be increased or He gas must be used. Arc generation is better and should be welded with a lower voltage than He.
* He Gas: As the specific gravity is small, the gas flow rate must be increased. It is possible to increase the welding speed by using a voltage higher than Ar, but it is expensive.
* When hydrogen gas is added: It is possible to increase the welding speed by increasing the voltage and is advantageous for metals with high thermal conductivity. It is effective in welding Ni alloy and stainless steel and should not be used in hydrogen brittle base materials such as Al, Cu, Mg.
* Add 1% Oxygen to Arx: Effect of Hardening Arc
* Nitrogen Addition: Overheating arc can be generated during copper welding to overcome the welding difficulties caused by high thermal conductivity of copper.
As described above, various gases are used in the field, and accordingly, proper gas shielding should be made, and it is possible to reduce costs by checking the static pressure and dynamic pressure and precise flow rate setting and static pressure and dynamic pressure setting of various gas welding condition management. There is a need for a precision flowmeter that has the advantage of improving the welding quality by setting the proper flow rate and checking the dynamic pressure, improving the productivity by managing the dynamic pressure, and managing the static pressure to reduce downtime.
According to the present invention, there are many variables depending on the use environment conditions, temperature, humidity, and gas clogging due to the characteristics of the gas during arc welding using CO2 welding, MAG welding, MIG welding, TIG welding, PLAZMA welding and other shielding gases such as hydrogen and helium. Therefore, it is intended to invent a precision flowmeter according to the standard test result according to the dynamic pressure change actually used in the field.
The precision flow meter of the present invention is tested with a
The present invention can precisely set the flow rate and set the static pressure and dynamic pressure to reduce the cost, improve the welding quality by setting the proper flow rate and dynamic pressure, improve the productivity by managing the dynamic pressure setting and static pressure The welding time management standard is possible because it can shorten the time and can be calibrated by dynamic pressure according to the use environment of the site.
Looking at the configuration and operation of the present precision flowmeter based on the accompanying drawings as follows.
1 is a conventional flowmeter test configuration diagram, Figure 2 is a test configuration diagram of the present invention precision flowmeter, Figure 3 is a front view of the present invention flowmeter.
As shown in FIG. 1, the test configuration diagram of the existing
2 is a test configuration diagram for the precision flow meter 1 of the present invention, while a
3 is a front scale road of the present invention flow meter (1) is formed in the inner tube (4), the display scale (3) capable of measuring the dynamic pressure and the pressure gauge (2) to the outlet side of the precision flow meter (1) .
The present invention relates to a precision flowmeter (1) having a gauge attached structure for measuring the dynamic pressure that can set the precise flow rate for each individual welding machine, unlike the existing flowmeter, precise flow rate setting and precise pressure setting and static pressure and dynamic pressure management By setting the optimum flow rate for each welding machine, it can reduce excessive gas consumption and improve productivity and quality.
According to the present invention, the flow rate can be precisely set and the static pressure and the dynamic pressure can be set, thereby reducing the cost. The optimal dynamic pressure setting can reduce the gas consumption by up to 50% or more.
In addition, the welding quality can be improved by setting the proper flow rate and checking the dynamic pressure. If the flow rate is set high, the dynamic pressure is high, and the overflow phenomenon occurs, which prevents the quality deterioration such as excessive adhesion of the spatter to the pores, oxidation, cracks and nozzle inner diameter. can do.
Figures 1 and 2 show the welding conditions at the proper flow rate and high flow rate settings.
[Figure 1] [Figure 2]
And by setting and managing dynamic pressure, productivity can be confirmed by checking gas clogging (gas diffuser, cable twist, excess nozzle inner spatter), and improving productivity.
In addition, it is possible to reduce the downtime by managing the static pressure, by checking the gas leakage in advance of the hose has the advantage of reducing the failure check downtime.
In order to measure the performance of the precision flow meter 1 of the present invention, a
The flow meter (8) is a high-sensitivity, high-speed, high-accuracy mass flow meter using a thermal flow sensor (Micro Flow) and high reliability (± 3%, ± 5%) and high speed response. It is easy to use and can be measured by various kinds of gas by using high level micro flow sensor. It is not affected by temperature and pressure.
■ Specification
Below is the test content of the precision flow meter 1 and the existing
[ test requirements ]
-Gas hose inner diameter Φ8, gas hose length 10m, welding
-Tested with mass flow meter (8), independent of pressure, temperature and humidity.
-Based on the flow meter (8), the flowmeter inner tube is designed according to the specific gravity for each welding gas based on the dynamic pressure of each instantaneous flow rate, and the flow and dynamic pressure are scaled together.
-Display scale (3): 5ℓ (0.01Kgf) / 10ℓ (0.3Kgf) / 15ℓ (0.3Kgf) / 20ℓ (0.5Kgf) / 25ℓ (0.7Kgf)
Specific gravity of each gas: air → 1 / argon → 0.38 / hydrogen → 0.069 / helium → 0.138 / carbon dioxide → 1.521
-Static pressure fluctuations, temperature, humidity, back pressure, etc. are the same and corrected if only dynamic pressure is matched.
-Flowmeter proper range: 25ℓ / min · 20 ℃ · 1.5Kgf / ㎠
-Satisfies the flow rate and the proper pressure of static pressure and dynamic pressure differential pressure is 1.5Kgf
-The proper temperature to maintain static pressure is 20 ℃
-Humidity decreases when temperature rises in a confined space, and decreases when temperature decreases.
-Humidity 40% ~ 70% RH, proper condition, 70% or more humid condition, 40% or less dry condition
▷ There are two types of flow rate measurement: instantaneous flow rate measurement, which calculates the rate of gas flow per unit time in the measurement pipeline, and integrated flow rate measurement, which calculates the flow time of gas.
□ Test 1. Instantaneous flow rate and dynamic pressure measurement according to the static pressure fluctuation
-Changing the pressure after setting the existing static pressure changes the flow rate and dynamic pressure.
□
-Variation in static pressure, dynamic pressure and instantaneous flow rate is severe due to the change of humidity.
-The secondary gas hose is made of rubber and the pressure changes due to the change in the volume of the hose due to the change in pressure and temperature.
□
-After setting the same static pressure and flow rate, the pressure fluctuation and the differential pressure occur according to the gas hose length.
□ Test 4. Measurement of dynamic pressure by static pressure after setting instantaneous flow rate in flow meter
-The dynamic pressure for the set flow rate is the same for each static pressure.
□
-By reducing the differential pressure of dynamic pressure to the lowest static pressure as low as possible, the gas consumption is reduced and the arc start property is improved. The bead surface is beautiful and the spatter is much reduced.
□
-Static pressure fluctuates due to the difference in specific gravity of the gas.
□
-The existing flowmeter is designed with high dynamic pressure structure.
□
-On-site users use the welding condition setting data (AWS, JIS) as a standard, but they are actually using excessive gas consumption.
□
Test results according to field application based on dynamic pressure can be seen that the precision flowmeter of the present invention is reduced by 44.7% and 34.7%, respectively, compared to the conventional flowmeter.
[Test Result]
-Pressure gauge on the outlet side of the precision flowmeter can be used to compensate for changes in the operating environment.
-Existing flowmeters have a structure with excessive flow rate, and the dynamic pressure is high, so that the quality of machining bead surface, oxidation, and crack resistance is not good, but users are increasing the gas flow rate setting if the quality of weld bead surface is poor.
-On-site flow rate setting is based on dynamic pressure and can be corrected by accurate flow rate.
As described above, in the present invention, the flowmeter can accurately adjust the gas flow rate compared to the existing flowmeter and can check the dynamic pressure of the flow rate, thereby improving welding failure and productivity.
In addition, by confirming the gas leakage of the gas hose in advance, it is possible to shorten the downtime such as failure confirmation.
In the existing centralized welding line, a gauge that manages only the main pipe static pressure is installed and used, but in the present invention, it is possible to simultaneously control the static pressure and the dynamic pressure on individual welders.
1 is a conventional flow meter test configuration.
Figure 2 is a test configuration of the present invention precision flow meter.
Figure 3 is a front view of the present precision flow meter.
<Description of the code | symbol about the principal part of drawing>
1: precision flowmeter 2: pressure gauge
3: display scale 4: inner tube
5: gas cylinder 6: primary pressure gauge
7: pressure gauge 8: flow meter
9: welder 10: conventional flow meter
11: feeder 12: torch
Claims (1)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020080074336A KR20100012768A (en) | 2008-07-28 | 2008-07-28 | Flow meter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020080074336A KR20100012768A (en) | 2008-07-28 | 2008-07-28 | Flow meter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| KR20100012768A true KR20100012768A (en) | 2010-02-08 |
Family
ID=42086952
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR1020080074336A KR20100012768A (en) | 2008-07-28 | 2008-07-28 | Flow meter |
Country Status (1)
| Country | Link |
|---|---|
| KR (1) | KR20100012768A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105625009A (en) * | 2014-11-05 | 2016-06-01 | 浙江雅莹集团有限公司 | Three-dimensional ironing table |
| CN115200774A (en) * | 2022-07-22 | 2022-10-18 | 北京超测智能系统有限公司 | Method and system for measuring or adjusting gas pressure in submerged arc furnace |
-
2008
- 2008-07-28 KR KR1020080074336A patent/KR20100012768A/en not_active Application Discontinuation
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105625009A (en) * | 2014-11-05 | 2016-06-01 | 浙江雅莹集团有限公司 | Three-dimensional ironing table |
| CN115200774A (en) * | 2022-07-22 | 2022-10-18 | 北京超测智能系统有限公司 | Method and system for measuring or adjusting gas pressure in submerged arc furnace |
| CN115200774B (en) * | 2022-07-22 | 2023-12-01 | 北京超测智能系统有限公司 | Method and system for measuring or adjusting gas pressure in submerged arc furnace |
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