CN212168927U

CN212168927U - Double-loop double-station magnesium alloy low-pressure casting gas mixing device

Info

Publication number: CN212168927U
Application number: CN202020250234.2U
Authority: CN
Inventors: 李来升; 康敬乐; 朱亮; 孙玉霞; 赵林栋; 蔡少刚; 怀松松
Original assignee: Sinomach Casting & Forging Machinery Co ltd
Current assignee: Sinomach Casting & Forging Machinery Co ltd
Priority date: 2020-03-03
Filing date: 2020-03-03
Publication date: 2020-12-18
Anticipated expiration: 2030-03-03

Abstract

The utility model provides a two return circuits duplex position magnesium alloy low pressure casting mixes gas device, including a muddy gas pitcher, a muddy gas pitcher is connected with compressed air return circuit and inert gas return circuit respectively, the compressed air return circuit is connected with the compressed air device, the inert gas return circuit is connected with SF6 air feeder, install third pressure switch and first SF6 infrared sensor subassembly on a muddy gas pitcher, the export of a muddy gas pitcher passes through the pipeline and mixes the entry UNICOM of gas pitcher No. two, set up the third solenoid valve on the pipeline between a muddy gas pitcher and No. two muddy gas pitchers, install fourth pressure switch and second SF6 infrared sensor subassembly on No. two muddy gas pitchers, the export of No. two muddy gas pitchers is connected with the air feed end of two low pressure casting devices respectively. The production efficiency of the low-pressure casting process of the magnesium alloy can be effectively improved.

Description

Double-loop double-station magnesium alloy low-pressure casting gas mixing device

Technical Field

The utility model relates to a magnesium alloy casting field, in particular to a double-loop double-station magnesium alloy low-pressure casting gas mixing device.

Background

In the low-pressure casting process of magnesium alloy, in order to prevent oxidation reaction after the magnesium alloy liquid contacts with air, a mixed gas of air and inert gas with certain pressure is introduced into casting equipment through a gas mixing device, the mixed gas drives the magnesium alloy liquid to enter a casting mold, and the low-pressure casting process is finally completed through the steps of pressurization, pressure maintaining, pressure relief, delayed mold opening (cooling) and the like. When the pressure maintaining, pressure relief and delayed opening (cooling) processes are carried out, the gas mixing device does not need to continuously supply mixed gas to the casting equipment, so that the waiting time in the low-pressure casting process of the magnesium alloy is longer, and the production efficiency is lower.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a gas mixing device is thoughtlessly cast to two return circuits duplex position magnesium alloy low pressure, and it can effectively promote the production efficiency of magnesium alloy low pressure casting technology.

The utility model discloses a realize above-mentioned purpose, realize through following technical scheme: including a muddy gas pitcher, a muddy gas pitcher is connected with compressed air return circuit and inert gas return circuit respectively, the compressed air return circuit is connected with the compressed air device, the inert gas return circuit is connected with SF6 air feeder, install third pressure switch and first SF6 infrared sensor subassembly on the muddy gas pitcher of a number, the export of a muddy gas pitcher passes through the entry UNICOM of pipeline and No. two muddy gas pitchers, set up the third solenoid valve on the pipeline between a muddy gas pitcher and No. two muddy gas pitchers, install fourth pressure switch and second SF6 infrared sensor subassembly on No. two muddy gas pitchers, the export of No. two muddy gas pitchers is connected with the air feed end of two low pressure casting devices respectively. The inert gas loop is connected in series through a pipeline by a second loop pressure reducing valve, a first pressure switch, a first speed control valve, a first flow switch, a first electromagnetic valve and a first one-way valve in sequence to form the inert gas loop, the first one-way valve is communicated with an inlet of a first gas mixing tank, the compressed air loop is connected in series through a pipeline by a first loop pressure reducing valve, a second pressure switch, a second speed control valve, a second flow switch, a second electromagnetic valve and a second one-way valve in sequence to form the compressed air loop, and the second one-way valve is communicated with an inlet of a first gas mixing tank. The two low-pressure casting devices are divided into a first pouring device and a second pouring device, the first pouring device is sequentially composed of a fourth electromagnetic valve and a first heat preservation furnace, and the second pouring device is sequentially composed of a fifth electromagnetic valve and a second heat preservation furnace; a liquid lifting pipe is arranged in the first heat preservation furnace and communicated with the casting mold, and a liquid lifting pipe is arranged in the second heat preservation furnace and communicated with the casting mold. The SF6 gas supply device is formed by connecting an SF6 gas cylinder and a filter pressure-reducing valve oil atomizer assembly in series, the filter pressure-reducing valve oil atomizer assembly is positioned between a second loop pressure-reducing valve and an SF6 gas cylinder, and the filter pressure-reducing valve oil atomizer assembly is formed by connecting a filter, a pressure-reducing valve and an oil atomizer in series. The compressed air device is formed by sequentially connecting an air storage tank, a main pipe filter, a first dryer, a first micro-mist separator and a second dryer in series, and the second dryer is communicated with the first loop pressure reducing valve. And a pilot reducing valve is arranged between the inert gas loop and the compressed air loop and is respectively connected with the second loop reducing valve and the first loop reducing valve. A liquid level pressurization system is arranged between the outlet of the second gas mixing tank and the two low-pressure casting devices, an outlet pipeline of the second gas mixing tank is communicated with the liquid level pressurization system, and the outlet of the liquid level pressurization system is respectively communicated with the two low-pressure casting devices. And an exhaust port of the first holding furnace is connected with an exhaust treatment device, and the exhaust treatment device is sequentially composed of a first cooler, a first throttle valve and a first pilot-operated electromagnetic valve. And an exhaust port of the second holding furnace is connected with an exhaust treatment device, and the exhaust treatment device is sequentially composed of a first cooler, a second throttle valve and a second pilot-operated electromagnetic valve.

The utility model has the advantages of: the double-loop double-station magnesium alloy low-pressure casting is realized in the magnesium alloy low-pressure casting production process, an alternate continuous production mode is created, and the production efficiency of the magnesium alloy low-pressure casting process is effectively improved.

Drawings

FIG. 1 is a schematic structural view of a double-loop double-station magnesium alloy low-pressure casting gas mixing device of the present invention,

reference numerals: 1 filter pressure reducing valve oil atomizer assembly, 2 second circuit pressure reducing valve, 3 first pressure switch, 3a second pressure switch, 4 first speed control valve, 5 first flow switch, 6 first solenoid valve, 7 first check valve, 8 main pipe filter, 9 first dryer, 10 first fine fog separator, 11 second dryer, 12 pilot pressure reducing valve, 13 first circuit pressure reducing valve, 14 second speed control valve, 15 second solenoid valve, 16 second check valve, 17 first air mixing tank, 18 third pressure switch, 18a fourth pressure switch, 19 first SF6 infrared sensor component, 19a second SF6 infrared sensor component, 20 third solenoid valve, 21 second solenoid valve, air mixing tank 22 fourth, 22a fifth solenoid valve, 23 first cooler, 23a second cooler, 24 first pilot solenoid valve, 24a second pilot solenoid valve, 25 second micro-fog separator, 26 second flow switch, 27 first throttle valve, 27a second throttle valve, 28 first holding furnace, 28a second holding furnace, 29 liquid level pressurizing system, 30 man-machine interface, 31 casting mold and 32 liquid supply pipe.

Detailed Description

A device of two return circuits duplex position magnesium alloy low pressure casting process of mixing gas, as shown in fig. 1, including a gas pitcher 17 that mixes, a gas pitcher 17 that mixes is connected with compressed air return circuit and inert gas return circuit respectively, the compressed air return circuit is connected with the compressed air device, the inert gas return circuit is connected with SF6 air feeder, install third pressure switch 18 and first SF6 infrared sensor subassembly 19 on a gas pitcher 17 that mixes, the export of a gas pitcher 17 that mixes passes through the pipeline and the entry UNICOM of a gas pitcher 21 that mixes, set up third solenoid valve 20 on the pipeline between a gas pitcher 17 that mixes and a second gas pitcher 21 that mixes, install fourth pressure switch 18a and second SF6 infrared sensor subassembly 19a on a gas pitcher 21 that mixes, the export of a gas pitcher 21 that mixes is connected with the air feed end of two low pressure casting devices respectively. The third pressure switch 18 and the fourth pressure switch 18a may be digital display pressure switches. In the above structure, the compressed air provided by the compressed air device is mixed with the inert gas provided by the SF6 gas supply device in the first gas mixing tank 17, after the mixed gas pressure of the first gas mixing tank 17 and the SF6 gas concentration reach preset process parameters, the third electromagnetic valve 20 is opened, the mixed gas enters the second gas mixing tank 21, and the second gas mixing tank 21 serves as a gas storage tank of the low-pressure casting system to provide the mixed gas meeting the requirements of the low-pressure casting process for the low-pressure casting system. The production processes of the two low-pressure casting devices are alternately carried out, when one low-pressure casting device is pressurized, the other low-pressure casting device carries out the steps of pressure maintaining, pressure relief and delayed mold opening (cooling), and the two groups of low-pressure casting devices always have a group of mixed gas provided by using the gas mixing device during production, so that the waiting time in the low-pressure casting process is eliminated, and the production efficiency of the low-pressure casting process of the magnesium alloy is effectively improved.

Inert gas return circuit and compressed air return circuit are used for respectively letting in corresponding gas to a gas mixing tank 17 in, choose for use general pipeline to just can realize above-mentioned basic function usually, nevertheless the utility model discloses a can realize gaseous accurate supply, the preferred following structure that adopts: the inert gas loop is formed by connecting a second loop pressure reducing valve 2, a first pressure switch 3, a first speed control valve 4, a first flow switch 5, a first electromagnetic valve 6 and a first one-way valve 7 in series through pipelines in sequence, the first one-way valve 7 is communicated with an inlet of a first gas mixing tank 17, the compressed air loop is formed by connecting a first loop pressure reducing valve 13, a second pressure switch 3a, a second speed control valve 14, a second flow switch 26, a second electromagnetic valve 15 and a second one-way valve 16 in series through pipelines in sequence, and the second one-way valve 16 is communicated with an inlet of the first gas mixing tank 17. The first flow switch 5 and the second flow switch 26 may be digital flow switches. The first solenoid valve 6 and the second solenoid valve 15 may be direct-acting two-way solenoid valves. The structure can realize the accurate configuration of the supply flow of the two gases, and is convenient for a computer to realize automatic control.

The two low-pressure casting devices of the present invention can be various low-pressure casting devices, for example, the two low-pressure casting devices are divided into a first pouring device and a second pouring device, the first pouring device is composed of a fourth electromagnetic valve 22 and a first holding furnace 28 in sequence, and the second pouring device is composed of a second three-way electromagnetic valve 22a and a second holding furnace 28a in sequence; a liquid lifting pipe is arranged in the first holding furnace 28 and communicated with the casting mold, and a liquid lifting pipe is arranged in the second holding furnace 28a and communicated with the casting mold. The fourth and

fifth solenoid valves

22 and 22a may be external pilot three-way solenoid valves. The fourth solenoid valve 22 and the fifth solenoid valve 22a are alternately opened and closed, so that the gas inlet path is cut off when the pressure of each holding furnace 28 is maintained, thereby preventing the pressure loss due to the backflow of the mixed gas.

To ensure that the SF6 used for casting is sufficiently pure, the second circuit pressure reducing valve 2 is connected to a SF6 gas supply, as shown in the upper left of fig. 1. The SF6 gas supply device is formed by connecting an SF6 gas cylinder and a filter pressure-reducing valve atomizer assembly 1 in series, the filter pressure-reducing valve atomizer assembly 1 is positioned between a second loop pressure-reducing valve 2 and an SF6 gas cylinder, and the filter pressure-reducing valve atomizer assembly 1 is formed by connecting a filter, a pressure-reducing valve and an atomizer in series. The gas in the SF6 gas cylinder is filtered by a filter, then is reduced by a pressure reducing valve, and finally is filtered by an oil atomizer to obtain pure SF6, and the pure SF6 is supplied to a second loop pressure reducing valve 2.

To obtain pure compressed air without moisture, the first circuit pressure reducing valve 13 is connected to a compressed air device, as shown in the upper left part of fig. 1. The compressed air device is formed by sequentially connecting an air storage tank, a main pipe filter 8, a first dryer 9, a first ultramicro mist separator 10 and a second dryer 11 in series, and the second dryer 11 is communicated with a first loop reducing valve 13. The compressed air is filtered twice by the main pipe filter 8 and the first micro-mist separator 10, and dried twice by the first drier 9 and the second drier 11, so that pure compressed air meeting the requirement of magnesium alloy low casting can be obtained. The first dryer 9 may be a freeze dryer. The second dryer 11 is a micro thermal adsorption dryer.

The purer compressed air and SF6 can effectively prevent the magnesium alloy liquid from generating strong oxidation reaction with gas, ensure the low-pressure casting to be smoothly carried out and eliminate potential safety hazard.

In order to ensure that the outlet pressures of the compressed air circuit and the inert gas circuit are consistent, as shown in the middle of fig. 1, a pilot pressure reducing valve 12 is installed between the inert gas circuit and the compressed air circuit, and the pilot pressure reducing valve 12 is respectively connected with the second circuit pressure reducing valve 2 and the first circuit pressure reducing valve 13.

In order to realize automatic accurate control, as shown in the lower right part of fig. 1, a 29 liquid level pressurization system is installed between the outlet of the second gas mixing tank 21 and the two low-pressure casting devices, the outlet pipeline of the second gas mixing tank 21 is communicated with the liquid level pressurization system 29, and the outlet of the liquid level pressurization system 29 is respectively communicated with the two low-pressure casting devices. The level pressurization system 29 may be an electronically controlled proportional valve. The liquid level pressurizing system 29 may also be an existing pneumatic control cabinet with a human-machine interface 30, which can remotely adjust the opening of various electromagnetic valves to realize the adjustment of pressure and flow, a controller in the pneumatic control cabinet can be used for setting programs, and the liquid level pressurizing system 29 can automatically adjust the opening of the pilot pressure reducing valve 12, the second loop pressure reducing valve 2, the first loop pressure reducing valve 13, the first speed control valve 4 and the second speed control valve 14 according to the preset programs and various parameters, so that the design process curve change of air supply pressure and flow in the pouring process is realized to realize accurate air supply.

In order to facilitate the concentrated treatment of the discharged mixed gas discharged from the holding furnace, as shown in the lower part of the center of fig. 1, the exhaust gas treatment device is connected to the exhaust port of the first holding furnace 28, and the exhaust gas treatment device is composed of a first cooler 23, a first throttle valve 27, and a first pilot-operated solenoid valve 24 in this order. The exhaust gas treatment device is connected to the exhaust port of the second holding furnace 28a, and the exhaust gas treatment device is composed of a first cooler 23a, a second throttle valve 27a, and a second pilot-operated solenoid valve 24a in this order. The first pilot operated solenoid valve 24 and the second pilot operated solenoid valve 24a may be connected to a recovery device. The mixed gas after cooling and pressure reduction can be sent to a recovery device. The first cooler 23 and the first cooler 23a may be spiral coolers. The first throttle 27 and the second throttle 27a may be proportional flow valves.

Double-loop double-station magnesium alloy low-pressure casting gas mixing process device, which is specifically operated as follows:

step 1, on one hand, compressed air from a factory is filtered and then filled into an air storage tank, and then the compressed air is subjected to double filtration and double-stage drying sequentially through a main pipe filter 8, a first dryer 9, a first micro-mist separator 10 and a second dryer 11, so that high-purity compressed air without any moisture is obtained. On the other hand, the SF6 from the factory is filtered, depressurized and oilmist removed by a filter, a pressure reducing valve and an oil mist sprayer to obtain pure SF 6.

Step 2, a pilot pressure reducing valve 12 is used for respectively controlling a first loop pressure reducing valve 13 in a compressed air loop and a second loop pressure reducing valve 2 in an inert gas loop of the compressed air loop, so that the outlet pressure of the compressed air loop or the inert gas loop is kept consistent;

when the pressure of the compressed air loop or the inert gas loop is too low, the first pressure switch 3 and the second pressure switch 3a respectively send a signal to alarm, and the pressure and the opening degree of the pilot reducing valve 12 are required to be adjusted, so that the compressed air loop or the inert gas loop reaches the required pressure value;

when the gas flow in the compressed air circuit or the inert gas circuit is controlled within the upper and lower limits of the set first flow switch 5 and the set first electromagnetic valve 6, a user can set the proportional opening of the second speed control valve 14 of the compressed air circuit on the human-computer interface 30, so that the output of the compressed air flow can be automatically controlled, and also can set the proportional opening of the first speed control valve 4 of the inert gas circuit and can also automatically control the output of the SF6 flow;

and step 3, when the first gas mixing tank 17 starts to be inflated, the first electromagnetic valve 6 and the second electromagnetic valve 15 in the double-loop can be electrified and opened at the same time, and gas mixing can be started in the first gas mixing tank 17 according to different set flow rates and different pipe diameters. The first air mixing tank 17 is provided with 19 for on-line continuous detection and feedback control.

When the signal of low concentration of SF6 in the first air mixing tank 17 is detected at 19, the proportional opening degree of the first speed control valve 4 is controlled to be increased to increase the composition of SF6, and similarly, the proportional opening degree of the second speed control valve 14 for compressed air is decreased to relatively increase the composition of SF 6.

And step 4, setting values of parameters in the first gas mixing tank 17 are as follows: when the pressure is in the range of 5.0-5.5 kgf/cm2 and the concentration of SF6 is in the range of 0.15-0.35%, the pilot-operated two-way solenoid valve 20 is powered on and opened, the mixed gas in the first gas mixing tank 17 enters the second gas mixing tank 21, and the first gas mixing tank 17 starts to charge the second gas mixing tank 21.

When the pressure in the first air mixing tank 17 or the concentration of SF6 is inevitably reduced after the first air mixing tank 17 charges the second air mixing tank 21, the user can respectively adjust the proportional opening of the first flow switch 5 and the proportional opening of the second flow switch 26 for compressed air in the SF6 loop on the man-machine interface 30 to increase the charging flow rate of the first air mixing tank 17. When the pressure range of the mixed gas and the concentration range of the SF6 reach the set value of the first gas mixing tank 17, the solenoid valve pilot type two-way solenoid valve 20 can be electrified and opened again, and at the moment, the mixed gas in the first gas mixing tank 17 is filled into the second gas mixing tank 21 again.

This is repeated many times, and the mixed gas having a certain pressure and inert gas components in the first gas mixing tank 17 is continuously charged into the second gas mixing tank 21 under the action of the pressure, and the second SF6 infrared sensor assembly 19a and the fourth pressure switch 18a are arranged in the mixed tank, so that the feedback control of the continuous charging is realized.

And step 5, when the gas mixing pressure in the second gas mixing tank 21 is kept within the range of 4.0-5.0 kgf/cm2 and the concentration of SF6 is kept within the range of 0.20-0.30%, the conditions for low-pressure casting of the magnesium alloy are met.

Step 6, when the second gas mixing tank 21 supplies gas to the first holding furnace 28 to pour, a set process curve with liquid lifting, filling, crystallization, pressurization, pressure maintaining, pressure relief, delayed opening and the like is set on the liquid level pressurization system 29, pouring is started after confirmation, at the moment, the fourth electromagnetic valve 22 is powered on and is powered off, the fifth electromagnetic valve 22a is powered off and is closed, the mixed gas in the second gas mixing tank 21 enters the inlet of the liquid level pressurization system 29 after being filtered by the second micro-mist separator 25, passes through an electric control proportional valve of the liquid level pressurization system 29, according to closed-loop feedback control of a pressure sensor, an actual process curve with pressure regularly changing along with time is output, the actual process curve and the set process curve of the magnesium alloy liquid are compared under the control of the liquid level pressurization system 29, the pressure and the flow of the supplied gas can be adjusted at any time to enable the pressure and the flow of the supplied gas to accord with the parameter values, and realizing proportional servo control.

And step 7, when the magnesium alloy liquid in the heat preservation furnace 28 is poured and pressure maintaining is finished, and the mixed gas is exhausted, firstly, the high-temperature mixed gas is cooled by the first cooler 23 and is exhausted through the first throttling valve 27 under the control of the first pilot-operated electromagnetic valve 24, and the exhausted mixed gas can be introduced into the recovery device for exhausting.

Step 8, when the second holding furnace 28a is used for pouring, a set process curve with liquid lifting, filling, crystallization, pressurization, pressure maintaining, pressure relief, delayed opening and the like is set on the liquid level pressurization system 29, pouring is started after confirmation, at the moment, the fourth electromagnetic valve 22 is powered off and closed, the fifth electromagnetic valve 22a is powered on and opened, the mixed gas in the second gas mixing tank 21 can enter the inlet of the liquid level pressurization system 29 through the second micro-mist separator 25 and passes through an electric control proportional valve in the liquid level pressurization system 29, according to the closed-loop feedback control of the pressure sensor, the actual process curve of which the output pressure changes regularly along with the time is compared with the set process curve by the magnesium alloy liquid under the control of the liquid level pressurization system 29, the pressure and flow of the supplied air can be adjusted at any time to make the supplied air accord with the parameter values specified by the set process curve, and the proportional servo control is realized.

And 9, when the magnesium alloy liquid in the second holding furnace 28a is poured and pressure maintaining is finished, and SF6 is exhausted, firstly, the high-temperature mixed gas is cooled by the first cooler 23a and is exhausted by the second throttling valve 27a under the control of the second pilot-operated electromagnetic valve 24a, and the exhausted mixed gas can be introduced into a recovery device for exhausting.

And step 10, sequentially carrying out the magnesium alloy low-pressure casting production process of the first heat preservation furnace 28 and the second heat preservation furnace 28a, realizing a double-loop double-station magnesium alloy low-pressure casting process, creating an alternate continuous production mode, effectively improving the production efficiency of the magnesium alloy low-pressure casting process, and meeting the requirements of various small-batch markets.

The above description is only for the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present invention, and all should be covered within the protection scope of the present invention. Therefore, all the equivalent structures or equivalent flow changes made by the contents of the specification and the drawings of the present invention, or the direct or indirect application thereof to other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. Double-loop double-station magnesium alloy low-pressure casting gas mixing device is characterized in that: comprises a first gas mixing tank (17), the first gas mixing tank (17) is respectively connected with a compressed air loop and an inert gas loop, the compressed air loop is connected with a compressed air device, and the inert gas loop is connected with SF₆The air feeder connects, install third pressure switch (18) and first SF6 infrared sensor subassembly (19) on a gas mixing tank (17), the export of a gas mixing tank (17) passes through the pipeline and mixes the entry UNICOM of gas mixing tank (21) No. two, set up third solenoid valve (20) on the pipeline between a gas mixing tank (17) and a gas mixing tank (21) No. two, install fourth pressure switch (18a) and second SF6 infrared sensor subassembly (19a) on a gas mixing tank (21) No. two, the export of a gas mixing tank (21) is connected with the air feed end of two low pressure casting devices respectively.

2. The double-loop double-station magnesium alloy low-pressure casting gas mixing device according to claim 1, characterized in that: the inert gas loop is formed by connecting a second loop pressure reducing valve (2), a first pressure switch (3), a first speed control valve (4), a first flow switch (5), a first electromagnetic valve (6) and a first one-way valve (7) in series through pipelines, the first one-way valve (7) is communicated with an inlet of a first gas mixing tank (17), the compressed air loop is formed by connecting a first loop pressure reducing valve (13), a second pressure switch (3a), a second speed control valve (14), a second flow switch (26), a second electromagnetic valve (15) and a second one-way valve (16) in series through pipelines, and the second one-way valve (16) is communicated with an inlet of the first gas mixing tank (17).

3. The double-loop double-station magnesium alloy low-pressure casting gas mixing device according to claim 1, characterized in that: the two low-pressure casting devices are divided into a first pouring device and a second pouring device, the first pouring device is sequentially composed of a fourth electromagnetic valve (22) and a first heat preservation furnace (28), and the second pouring device is sequentially composed of a second three-way electromagnetic valve (22a) and a second heat preservation furnace (28 a); a liquid lifting pipe is arranged in the first holding furnace (28) and communicated with the casting mold, and a liquid lifting pipe is arranged in the second holding furnace (28a) and communicated with the casting mold.

4. The double-loop double-station magnesium alloy low-pressure casting gas mixing device according to claim 2, characterized in that: the SF₆The gas supply device is composed of SF₆The gas cylinder and the filter pressure reducing valve atomizer assembly (1) are connected in series, and the filter pressure reducing valve atomizer assembly (1) is positioned between the second loop pressure reducing valve (2) and SF₆Between the gas cylinders, the filter pressure reducing valve atomizer assembly (1) is formed by connecting a filter (1a), a pressure reducing valve (1b) and an atomizer (1c) in series.

5. The double-loop double-station magnesium alloy low-pressure casting gas mixing device according to claim 2, characterized in that: the compressed air device is formed by sequentially connecting an air storage tank, a main pipe filter (8), a first dryer (9), a first ultramicro mist separator (10) and a second dryer (11) in series, and the second dryer (11) is communicated with a first loop reducing valve (13).

6. The double-loop double-station magnesium alloy low-pressure casting gas mixing device according to claim 2, characterized in that: and a pilot reducing valve (12) is arranged between the inert gas loop and the compressed air loop, and the pilot reducing valve (12) is respectively connected with the second loop reducing valve (2) and the first loop reducing valve (13).

7. The double-loop double-station magnesium alloy low-pressure casting gas mixing device according to claim 1, characterized in that: a liquid level pressurizing system (29) is arranged between the outlet of the second gas mixing tank (21) and the two low-pressure casting devices, the outlet pipeline of the second gas mixing tank (21) is communicated with the liquid level pressurizing system (29), and the outlet of the liquid level pressurizing system (29) is respectively communicated with the two low-pressure casting devices.

8. The double-loop double-station magnesium alloy low-pressure casting gas mixing device according to claim 3, characterized in that: the exhaust treatment device is connected with an exhaust outlet of the first holding furnace (28), the exhaust treatment device is sequentially composed of a first cooler (23), a first throttle valve (27) and a first pilot-operated electromagnetic valve (24), the exhaust outlet of the second holding furnace (28a) is connected with the exhaust treatment device, and the exhaust treatment device is sequentially composed of a first cooler (23a), a second throttle valve (27a) and a second pilot-operated electromagnetic valve (24 a).