JPH08296910A - Cooling method of cooling water by compressed gas refrigerant - Google Patents

Abstract

PURPOSE: To enable continuous welding by cooling a cooling water with a low temperature compressed gas converted from a compressed gas with the expansion thereof to chill the cooling water for welding so that the temperature of the cooling water after the welding is kept the same as at the start of the welding or lower. CONSTITUTION: A compressed gas taken in from a supply connection port 6 of compressed air E undergoes a dehumidification and a removal of impurities through a filter 8. An adjustment of pressure is performed by a decompression value 9 with a manometer, the adjustment of a flow rate by a flow meter 10 for the compressed gas and the compressed gas is fed into a compressed gas supply port 3 of a cooler 2. The compressed gas entering the compressed gas supply port 3 is changed to a chilled gas inside to be discharged. The temperature of the water for cooling during the welding rises to at least about 50 deg.C after the cooling. The temperature of water cooled C during the welding is kept at about 10-25 deg.C depending on the conditions to form a better welding metal with a higher cooling effect. The compressed gas is changed to the chilled gas to cool the cooling water C of raised up high temperature down to 10-25 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling method for cooling water in general welding using a water-cooled copper alloy.

[0002]

2. Description of the Related Art A water-cooled copper alloy is generally used when it is necessary to form a weld metal in a certain shape and expose the welded portion to the outside. Inside the water-cooled copper alloy, cooling pipes for passing cooling water are built-in, and due to the excellent thermal conductivity of copper, cooling of the portion that contacts the weld metal without burning the copper alloy To obtain a good bead appearance and prevent welding of the water-cooled copper metal and the weld metal. If the copper dope is not cooled with water, the copper dowel and the welded part will be welded together, and the copper dowel cannot be removed.

The cooling water supply system is roughly divided into the following two types. One is a cooling method in which the cooling water stored in the tank is cooled by a blower, the cooling water is pumped by a pump to cool the copper metal, and then the cooling water is returned to the tank again. There is a method in which a cooling water pipe is directly attached to a copper plate from a tap water or industrial water faucet, and after cooling the copper plate, the cooling water is directly supplied to the drain port.

Although the water temperature after cooling varies depending on the welding method, welding time, cooling area and the number of copper alloys, the cooling water temperature after welding is usually higher than the water temperature before welding. Particularly in high heat input welding, the water temperature may be 50 ° C. or higher and the cooling effect may not be obtained by the circulation method. Therefore, it is necessary to cool the water until it returns to a water temperature suitable for cooling. Since the circulation method is almost air-cooled, it takes a long time to cool.

In the drainage system, the water temperature varies depending on the season, and especially in the summer, the water temperature is high, so that it takes time to cool. In some cases, it may not be suitable for cooling water. In addition, the cooling water may boil during welding and the welding may have to be interrupted. In this way, it takes a very long time for the cooling water temperature during and after welding to return to the water temperature suitable for cooling.Therefore, this is a major obstacle when the welding location is long or when continuous welding is desired. Has become.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems and maintains a water temperature suitable for cooling during welding, so that the cooling water temperature after welding can be set at the start of welding or at the start of welding. The purpose is to maintain the following water temperature, prevent boiling during welding, eliminate welding waiting time, and supply cooling water that enables continuous welding.

[0007]

Means for Solving the Problems The present invention is to solve the above problems, in which a compressed gas is expanded and converted into a low temperature compressed gas, and cooling water is cooled by the low temperature compressed gas to cool for welding. A cooling water cooling method using a compressed gas refrigerant, characterized by cooling water. In addition, here, a compressed gas is blown along the circumference of the cylinder to generate an ultra-high-speed vortex, a low-temperature compressed gas is generated in the center of the cylinder, and when cooling the cooling water with the low-temperature compressed gas, It is also characterized by mixing with cooling water and then separating the gas from the cooling water.

[0008]

The cooling water cooling method using the compressed gas refrigerant of the present invention will be described in detail with reference to FIG. FIG. 1 is an explanatory view showing an example of an apparatus for carrying out a cooling water cooling method using a compressed gas refrigerant of the present invention. First, regarding the detailed structure of the apparatus, the cooler 2 is installed in the substantially central portion of the cooling water cooling apparatus main body 1. A manual opening / closing valve 7, a filter 8, a pressure reducing valve 9 with a pressure gauge, and a flow meter 10 for compressed gas are attached to a piping system that connects the supply connection port 6 of the compressed gas E to the cooler 2. Further, the low-temperature compressed gas discharge port 5 is passed through the supply pipe 15 in which the automatic opening / closing valve 11, the gas check valve 16 and the liquid check valve 17 are installed, and between the liquid check valve 26 and the buffer tank inlet 18. Connected to.

Further, a manual opening / closing valve 23, a pressure gauge 25, and a flowmeter 2 are provided between the supply port 21 and the discharge port 22 of the cooling water C.
4, an automatic opening / closing valve 41, a liquid check valve 26, a buffer tank 19, a liquid check valve 29, and an aspirator 35 are installed. Relief valves 27A and 27B and pressure gauges 28A and 28B are attached to the upper portion of the buffer tank 19, and an exhaust treatment tank 31 is provided from the relief valves 27A and 27B through a decompression exhaust pipe 30 and connected to the exhaust port 14.

On the other hand, the exhaust port 4 of the cooler 2 mainly has a structure in which a check valve for gas 13 is sandwiched between the exhaust port 4 and the exhaust port 12 and the exhaust port 14 is connected. Further, the cooling water cooling device body 1 can be moved by wheels 42.

Next, the function of each part of the apparatus will be described.
The compressed gas taken from the supply connection port 6 of the compressed gas E is
Dehumidification and removal of impurities are performed through the filter 8. Then, the pressure reducing valve 9 with a pressure gauge adjusts the pressure, and the compressed gas flow meter 10 adjusts the flow rate, and the compressed gas adjusted to an appropriate state is introduced into the compressed gas supply port 3 of the cooler 2. The compressed gas that has entered the compressed gas supply port 3 is changed into a cold gas inside and is discharged. The optimum pressure range of the compressed gas required to maximize the cooling capacity of the cooler 2 is 4 to 10 kg / c.
At m ² , the flow rate is about 50 to 300 liters / min.

FIG. 3 shows an example of changes in the compressed gas pressure and the temperature of the cold gas A when the compressed gas supply temperature is 15 ° C. and the discharge flow rate is 300 liters / min. The discharge temperature of the cold gas A discharged from the low temperature compressed gas discharge port 5 when the compressed gas pressure is 4 kg / cm ² and 10 kg / cm ² is 4 kg.
/ Cm ² −15 ° C., 10 kg / cm ² −30 ° C.
Is.

The temperature of the cooling water during welding varies depending on the welding method, the welding time, the cooling area and the number of copper deposits, but it rises to at least about 50 ° C. after cooling. According to the present invention, the water temperature of the cooling water C during welding is maintained at about 10 to 25 ° C or lower depending on the conditions to enhance the cooling effect and form a good weld metal. Cooling water C that has become high temperature 10
The compressed gas is changed to the cold gas A in order to cool it to about 25 ° C. The operating principle of the cooler 2 will be described. FIG. 2 shows an internal schematic diagram of the cooler 2.

When the compressed gas is blown from the compressed gas supply port 3 along the circumference of a cylinder 43 having an orifice at one end and a donut-shaped exhaust port 4 at the other end like the low temperature compressed gas discharge port 5, the cylinder 43 is blown. An ultra-high speed vortex with 200,000 to 300,000 revolutions per minute is created. Therefore, the central portion 44 and the outer peripheral portion 45 of the vortex
A large pressure difference is generated between the two, and the gas moves toward the center, causing the temperature to drop due to expansion. The cold gas A generated in the central portion flows out from the low temperature compressed gas discharge port 5, and the hot gas B on the outer periphery is discharged from the exhaust port 4 having a donut-shaped gap.

The hot gas B discharged from the exhaust port 4 of the cooler 2 passes through the exhaust pipe 12, passes through the gas check valve 13 provided for preventing exhaust backflow, and is discharged to the outside from the exhaust port 14. It On the other hand, the cold gas A discharged from the low temperature compressed gas discharge port 5 flows from the supply pipe 15 into the buffer tank through the automatic opening / closing valve 11, the gas check valve 16 and the liquid check valve 17.

Almost at the same time, the cooling water C connected to the liquid supply port 21 flows toward the buffer tank after the amount of water is adjusted by the manual opening / closing valve 23 and the flow meter 24. Pressure gauge 2
Reference numeral 5 is used for confirming the supply pressure of the cooling water C, and the automatic opening / closing valve 41 opens the valve to allow water to flow in conjunction with the start of cooling of the device of the present invention. The valve is closed when the system is stopped. At the buffer tank inlet 18, the cold gas A that has cooled the compressed gas flowing toward the buffer tank and the cooling water C collide with each other, and the discharge pressures of both the cold gas A and the cooling water C are added to the pressurized state. Become.

For example, the discharge pressure of the cold gas A is 5 kg / cm.
² and the discharge pressure of the cooling water C is 3 kg / cm ² , the internal pressure of the buffer tank inlet 18 is (3 + 5) kg /
the 8kg / cm ² about in cm ^2. The pressure inside the pipe between the supply port 21 and the discharge port 22 of the cooling water C is the same (3 kg
/ Cm ² and 3 kg / cm ² ) with the same pipe diameter,
The cooling water C flows in a smooth laminar flow state. However, even if the supply and discharge side pipe diameters are the same, if the cooling water C supplied at a constant supply pressure is pressurized, it will be in a pulsating state. The degree of pulsating flow varies depending on the pipe shape and collision angle, but when gas is pressurized against liquid, the gas and liquid become agitated and the cooling water containing bubbles is intermittently intermittently (gas space and The liquid space is mixed and the gas part is discharged randomly in the pipe). Therefore, the cooling water C after the discharge port 22 forms a gas space in the liquid and a pulsating flow occurs, and the water flows in an intermittent state, so that the cooling effect is significantly reduced as compared with the case of filling the pipe with the liquid. .

When the cold gas A is introduced into the cooling water C for cooling, the discharge pressure of the cold gas A flowing toward the buffer tank inlet 18 is the same on both the buffer tank 19 side and the liquid check valve 26 side. Take If the check valve 26 for liquid is not installed, the back pressure is applied to the cooling water C flowing from the supply port 21 side, and the supply pressure is reduced, and the cooling flow rate is greatly affected. In order to prevent this, a check valve 26 for liquid was installed. Also, a check valve for liquid 1
7 and the check valve 16 for gas are installed, the cooling water C may flow into the cooler 2 when the discharge pressure of the cold gas A decreases. A check valve for liquid 17 and a check valve for gas 16 are provided for the purpose of both the inflow and the backflow of the cold gas A.

A buffer tank 19 was installed in order to eliminate the above-mentioned state. The main role of the buffer tank 19 is to return the stirring water C for cooling to the laminar flow state to maximize the cooling effect. In order to return to the laminar flow state, it is necessary to reduce the discharge pressure of the cold gas that is being pressurized and reduce the supply pressure to about the supply pressure of the cooling water by utilizing only the heat exchange action. Therefore, the relief valve 27A,
27B is attached, and when the internal pressure becomes higher than the supply pressure of the cooling water C, the excess pressure is applied to the relief valve 27 for gas.
It escapes from A and 27B and is kept at the same pressure as the supply pressure of the cooling water C to enable water to flow in a laminar flow state, thereby improving the cooling effect.

The capacity of the buffer tank 19 needs to be larger than that of the pipe 36. For example, the cooling water C flowing in the pipe 36 is filled and allowed to flow through the pipe 3
When switching to a pipe thicker than 6, the flowing water portion and the space are divided, and the flow velocity becomes somewhat slower from the portion where the pipe diameter is switched. Utilizing this phenomenon, the flow velocity of the cooling water C is temporarily delayed in the buffer tank to change the pulsating flow to a state close to the laminar flow, and the gas relief valves 27A and 27B reduce the pressure to about the supply pressure of the cooling water C. Then, excess pressure is released from the exhaust port 14 through the reduced pressure exhaust pipe 30 and the exhaust treatment tank 31. The cooled cooling water C returns to the laminar flow state and is discharged from the discharge port 22.

In addition, a little liquid may be mixed in the excess pressure gas released from the gas relief valves 27A and 27B. The liquid mixed with the gas is introduced into the exhaust treatment tank 31, and the liquid and the gas are separated to some extent. In the exhaust treatment tank 31, a liquid separation filter 32, which is a combination of synthetic resin and fibers that blocks the passage of the liquid and allows only the gas to pass, is installed in the form of a curtain to separate the liquid and the gas. The liquid D is designed to collect on the bottom of the exhaust treatment tank 31, and the automatic opening / closing valve 33 is opened before the liquid D collects in association with the operation of the cooling water cooling device. The liquid D passes through the return pipe 34 having a diameter smaller than the pipe diameter between the supply port 21 and the discharge port 22 of the cooling water C, and flows into the pipe 36 on the discharge port 22 side. In order to make this pouring smooth, the liquid D flowing from the return pipe 34 is mixed with the cooling water C by the suction force generated from the flow velocity of the cooling water C flowing from the supply port 21 to the discharge port 22, and is discharged to the outlet 22 and thereafter. An aspirator 35 is installed for discharging. The liquid check valve 37 installed in front of the aspirator 35 receives the cooling water C flowing from the buffer tank outlet 20 side and flows into the exhaust treatment tank 3.
The liquid D is provided so as not to flow back to the first side and to allow the liquid D to quickly flow back into the pipe 36.

When the liquid D accumulated in the exhaust treatment tank 31 flows out slowly and the liquid D accumulates, the liquid level detection sensor 38 attached to the exhaust treatment tank 31 detects the rise of the liquid level. The discharge pump 39 is operated to forcefully flow into the pipe 36. A check valve for liquid 40 installed below the discharge pump 39 is provided to prevent backflow into the discharge pump 39.

In the cooling method of the present invention, the cooling water C can be continuously supplied for cooling, or the cooling water C can be intermittently supplied for cooling. When supplying the cooling water C intermittently, a certain amount of the cooling water C is caused to flow into the buffer tank 19, the automatic opening / closing valve 41 is closed, and cooling is performed by the discharge pressure of the cold gas A, while the cooling water C is supplied from the buffer tank outlet 20. The cooling water A is discharged. At this time, the relief valve 27A,
Adjust pressure at 27B. Then, this control is repeated to cool the cooling water C to about 10 to 25 ° C.

It is also possible to mount a temperature sensor on the buffer tank outlet 20 side and perform temperature control to automatically control the supply flow rate of compressed gas and the compressed gas pressure to control the cooling water C to a set temperature. Furthermore, tap water or industrial water is directly connected to the cooling water cooling device of the present invention, and a cooling system for draining the water after the cooling treatment or a system for cooling by installing it in a part of the piping system of the cooling water circulation device Can be used. Also, a cooling method other than the above-mentioned method can be used if the usage conditions are suitable.

The example of the present invention has been described in detail with reference to the drawings. However, this is a representative example and does not limit the scope of the present invention. It is included in the technical scope.

[0026]

EXAMPLE Using the material to be welded 48 having a plate thickness of 50 mm and a length of 500 mm shown in FIG. 4, electroslag welding, which is high heat input welding, was performed. In the figure, 46 is a water-cooled copper alloy, and 5
Reference numerals 0 and 51 are a cooling water supply port and a cooling water discharge port, respectively. Note that 47 is a steel dowel and 49 is a groove. Welding conditions are welding voltage 52V, welding current 380A, flux addition amount 105
g.

First, in order to confirm the cooling effect of the apparatus of the present invention and the flow state after cooling before welding, a preliminary investigation was carried out. Air compressed to 5 kg / cm ² from the compressed gas supply port 3 shown in FIG. 1 is adjusted to 100 liters / min and supplied, and the cooling water is stopped before welding is started to discharge only cold air. The temperature was measured at. The temperature of cold air is −
The temperature was 8 ° C., and the compressed air temperature before cooling was 16 ° C.

Next, with the cooling water cooling device 1 all in operation, cooling water C adjusted to a flow rate of 5 liters / min from the supply port 21 and cold air collide with each other at the buffer tank inlet 18 to perform cooling treatment. The water temperature before welding was measured. The water temperature after the cooling treatment was 3 ° C., and the temperature before the cooling treatment was 20 ° C., so that cooling could be performed at 17 ° C. Also,
The flow state of the cooling water flowing out from the discharge port 22 was almost the same as the supply side, and was a smooth laminar flow state. Then, when a water-cooled copper plate was attached to the outlet 22 side of the cooling water cooling device 1 and the surface temperature of the copper plate was measured, it was almost the same as the water temperature after cooling.

Therefore, the cooling water cooling device 1 of the present invention is actually used.
We decided to carry out electroslag welding using.
Cooling water is supplied by using a cooling method in which industrial water is passed through a water-cooled copper alloy, and is cooled and then drained. The cooling water and compressed air supplied to the cooling water cooling device 1 are based on the conditions of the preliminary survey shown above. It was done using.

As a result, the cooling water discharge temperature during welding was set to 18
It was possible to control the temperature within a range of up to 22 ° C, and a good cooling effect was obtained even in the welding with a large heat input, and stable welding could be performed. Further, the cooling water cooling device 1 was stopped 150 mm before the welding end portion, and the cooling water discharge temperature was measured when cooling was performed only by the cooling effect of industrial water. The temperature of the cooling water gradually increased and was raised to about 41 ° C. at the end of welding.

[0031]

By using the cooling water cooling method of the present invention, it is possible to further enhance the cooling effect of the water-cooled copper alloy applied to various types of welding including high heat input welding. As a result, it is possible to eliminate the inability of continuous welding due to the interruption of welding due to boiling of cooling water during welding and the insufficient cooling capacity, and to maintain a stable cooling water temperature to form a good weld metal. Value is very high.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an example of an apparatus for carrying out the present invention.

FIG. 2 Schematic diagram of the inside of the cooler

FIG. 3 is a graph showing an example of temperature changes of supplied compressed air and discharged cold air.

FIG. 4 is a perspective view of a test plate using a water-cooled copper plate.

[Explanation of symbols]

 1 Cooling Water Cooling Device Main Body 2 Cooler 3 Compressed Gas Supply Port 4 Exhaust Port 5 Low Temperature Compressed Gas Discharge Port 6 Compressed Gas Supply Connection Port 7,23 Manual Open / Close Valve 8 Filter 9 Pressure Reduction Valve with Pressure Gauge 10 Flowmeter for Compressed Gas 11, 33, 41 Automatic on-off valve 12 Exhaust pipe 13, 16 Gas check valve 14 Exhaust port 15 Supply pipe 17, 26, 29, 37, 40 Liquid check valve 18 Buffer tank inlet 19 Buffer tank 20 Buffer tank outlet 21 Supply Port 22 Discharge Port 24 Flow Meter 25, 28A, 28B Pressure Gauge 27A, 27B Relief Valve 30 Reduced Pressure Exhaust Pipe 31 Exhaust Treatment Tank 32 Liquid Separation Filter 34 Return Pipe 35 Aspirator 36 Piping 38 Liquid Level Detection Sensor 39 Discharge Pump 42 Wheels 43 Cylinder 44 Center of Vortex 45 Outer Part A Cold Gas B Hot Gas C Cooling water D Liquid E Compressed gas

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B23K 37/06 B23K 37/06 J F25D 9/00 F25D 9/00 B

Claims (3)

[Claims] 1. A cooling water cooling method using a compressed gas refrigerant, which comprises expanding a compressed gas to convert it into a low temperature compressed gas, cooling the cooling water with the low temperature compressed gas, and cooling the cooling water for welding. . 2. The cooling water by the compressed gas refrigerant according to claim 1, wherein the compressed gas is blown along the circumference of the cylinder to generate an ultra-high speed vortex, and the low temperature compressed gas is generated in the center of the cylinder. Cooling method. 3. The compressed gas according to claim 1, wherein when cooling the cooling water with the low temperature compressed gas, the low temperature compressed gas and the cooling water are mixed and then the gas is separated from the cooling water. Cooling method for cooling water using a refrigerant.