Device for acquiring gas-liquid phase equilibrium data of alloy under negative pressure

Abstract

The utility model discloses a device for acquiring alloy gas-liquid phase equilibrium data under negative pressure. The device comprises a gas-liquid phase circulating unit, a negative pressure acquisition and control unit, a heat source acquisition and control unit, a circulating water acquisition and control unit and a product cooling unit, the device has the characteristics of simple structure, convenience in operation and capability of accurately measuring gas-liquid phase equilibrium data in a negative pressure state, a circulating water cooling device is only arranged in the gas-liquid phase circulating reaction tank, so that a sealing gasket is protected from being damaged, the air tightness of equipment is ensured, and the liquid phase reactor and the upper and lower ends of a condensation collection cover are surrounded by a heat insulation layer, so that the gas-liquid phase equilibrium data can be accurately measured. The problem that gas-phase substances are directly solidified at the bottom of the gas-phase condensation collecting cover in a solid state and cannot form circulating balance between gas and liquid phases is fundamentally solved, and the normalization of gas-phase and liquid-phase total substance components is achieved on the basis of the gas-phase and liquid-phase balance principle.

Description

Technical Field

[0001] This utility model belongs to the field of metallurgical thermodynamic data measurement, specifically relating to a device for obtaining alloy gas-liquid phase equilibrium data under negative pressure. Background Technology

[0002] Matter exists in solid, liquid, gaseous, or any two or three phases coexisting under different temperatures and pressures. For elemental metals, under normal pressure, they are solid below their melting point, liquid above their melting point, and gaseous above their boiling point. However, as pressure decreases, the boiling point of metals also decreases, making them more likely to turn into a gaseous state upon heating. Therefore, in alloy separation and metal purification processes, distillation can be used to transform materials into a gas-liquid coexisting phase. Separation of elements / substances is achieved based on their different boiling points. Furthermore, reducing system pressure during distillation to create a negative pressure environment lowers the required distillation temperature and time, thus enhancing the process.

[0003] Under certain pressure and temperature, when alloy / metal materials are in a gas-liquid equilibrium state, the proportion of the same substance / element in the gas phase and the liquid phase remains constant. The content of this substance / element between the gas and liquid phases at this time is the gas-liquid equilibrium data of that substance / element. Gas-liquid equilibrium data is an important component of thermodynamic technical data. Through this data, the distribution pattern and separation effect of the substance / element during the distillation process can be predicted.

[0004] Currently, most equipment and methods for measuring gas-liquid phase equilibrium data are only applicable to the chemical industry. For example, patent CN113624570A, "Gas-liquid phase equilibrium device and analytical method for HF in fluorinated hydrocarbons," is characterized by the fact that the material to be tested is mainly in a liquid state at room temperature / non-high temperature (<100℃) and normal pressure. After the material is distilled, its gaseous products can either be directly coupled with a gas chromatograph / mass spectrometer to determine the components, or they can be condensed into a liquid state and directly sampled for component determination without disrupting the equilibrium of the measurement system (if the system needs to be restored to normal pressure).

[0005] However, in the metallurgical field, since the raw materials are mainly composed of metals / alloys, their melting and boiling points are relatively high. When the material is in a gas-liquid phase equilibrium state, the required temperature is high. At this time, the material cannot be directly coupled with analytical and testing equipment, and the original gas-liquid phase equilibrium data determination equipment and methods in the chemical field are no longer applicable. In existing literature, the gas-liquid phase equilibrium data of metals / alloys are usually determined by vacuum distillation furnaces. For example, as shown in the literature Wang Y, Chen L, Kong L, et al. Simulation prediction and experimental study of phase equilibria of Bi–Sb and Bi–Sb–Cd alloys in vacuum distillation[J]. Vacuum, 2023, 213:112032., in the process of determining the gas-liquid phase equilibrium data of Bi-Sb alloy, most of the Sb and a small part of Bi are distilled into the gas phase and then condensed by the condenser. After the experiment, the furnace lid is opened, and the material is taken from the crucible and the condenser to obtain the corresponding composition as the gas-liquid phase equilibrium data under this condition. However, according to the principle of gas-liquid phase equilibrium, when the gas phase is condensed into a solid, the substances in the gas phase cannot return to the liquid phase, and sufficient material flow cannot be formed between the gas and liquid phases, thus preventing the exchange of substances between them from reaching equilibrium. Patent CN206410904U describes an alloy gas-liquid phase equilibrium device, providing an apparatus suitable for determining alloy gas-liquid phase equilibrium. This device uses a rotating scraper to remove the solidified condensate from the condensation pan, allowing it to return to the liquid phase, thus ensuring that the liquid phase composition remains essentially unchanged. However, in practice, it is impossible to determine whether the solidified condensate has been completely removed from the condensation pan, and the operation is quite difficult. Utility Model Content

[0006] The purpose of this invention is to provide a device for obtaining alloy gas-liquid phase equilibrium data under negative pressure. This device has the characteristics of simple structure, convenient operation, and accurate measurement of metal / alloy gas-liquid phase equilibrium data.

[0007] The technical solution of this device is as follows: A device for acquiring alloy gas-liquid phase equilibrium data under negative pressure, including a gas-liquid phase circulation unit, a negative pressure acquisition and control unit, a heat source acquisition and control unit, a circulating water acquisition and control unit, and a product cooling unit;

[0008] The gas-liquid phase circulation unit includes a gas-liquid phase circulation reaction tank, a tank cover, a sealing ring, a sealing gasket, a tank support frame, a heat insulation layer, a liquid phase reactor, a gas phase condensate collection cover, a flexible isolation sheet, an extraction pipe, an inlet pipe, an extraction control valve, and an inlet control valve. The gas-liquid phase circulation reaction tank is cylindrical. The tank support frame is installed below the tank body to provide support for the gas-liquid phase circulation reaction tank and maintain its structural stability during operation. The flexible isolation sheet is rolled into a cylindrical shape and fitted into the gas... In the liquid-phase circulating reactor, flexible insulating sheets are tightly attached to the inner wall of the reactor. A cylindrical insulation layer is placed at the bottom of the reactor. Flexible insulating sheets are installed at the top and bottom of the lower insulation layer to prevent metal vapor from entering the insulation layer and to facilitate its reuse. The liquid-phase reactor containing the metal / alloy raw materials is placed on the lower insulation layer, and the gas phase condensate collection cover is placed at the opening of the liquid-phase reactor. Then, another insulation layer is installed above the horizontal plane of the gas phase condensate collection cover. Flexible insulating sheets are placed at the top and bottom of the upper insulation layer, respectively. A sealing gasket is placed in the groove at the inlet of the gas-liquid phase circulation reactor. A reactor lid with the same groove is placed above the gas-liquid phase circulation reactor, with the groove on the bottom surface of the reactor lid contacting the sealing gasket. The gas-liquid phase circulation reactor and the reactor lid are connected and sealed by the sealing gasket and sealing clamp. The exhaust port is located above the gas-liquid phase circulation reactor body, and an exhaust pipe is installed at the exhaust port. An exhaust control valve is installed on the exhaust pipe to control the negative pressure acquisition and control unit. The pumping rate of the vacuum pump; the air inlet is located at the bottom of the gas-liquid phase circulation reaction tank, which is convenient for connection with the negative pressure acquisition and control unit. An air inlet pipe is installed at the air inlet, and an air inlet control valve is installed on the air inlet pipe. This is to facilitate the maintenance of stable gas pressure in the gas-liquid phase circulation reaction tank after being connected with the negative pressure acquisition and control unit. At the same time, after closing the pumping control valve and the air inlet control valve, the entire gas-liquid phase circulation unit can maintain a constant pressure state for a short period of time. This is beneficial for disconnecting the gas-liquid phase circulation unit from other units after the reaction is completed and allowing it to enter the cooling unit for rapid cooling.

[0009] The negative pressure acquisition and control unit includes a vacuum pump, a pressure gauge, a flow meter, and a gas cylinder containing inert gas. The negative pressure acquisition and control unit is connected to the gas-liquid phase circulation unit via pipe I to provide negative pressure conditions for the gas-liquid phase circulation unit. The vacuum pump is connected to the suction pipe of the gas-liquid phase circulation unit via pipe I, and the connection is secured with clamp I for easy disassembly. The pressure gauge is directly connected to the vacuum pump to read the gas pressure within the gas-liquid phase circulation unit. The gas cylinder containing inert gas is connected to the inlet pipe of the gas-liquid phase circulation unit via pipe II, and the connection is secured with clamp II to provide atmosphere protection for the gas-liquid phase circulation unit and prevent oxidation of the raw materials. A flow meter is installed on the gas cylinder containing inert gas to control the gas flow rate from the gas cylinder into pipe II, facilitating stable gas pressure within the gas-liquid phase circulation unit when used in conjunction with the vacuum pump.

[0010] The heat source acquisition and control unit includes a heating element and a heating element control and temperature measurement system. The heating element is located outside the gas-liquid phase circulation unit and surrounds the gas-liquid phase circulation reaction tank. The height of the heating zone of the heating element is lower than the height of the gas phase condensation collection cover, providing a heat source for the melting of raw materials and the gas-liquid phase equilibrium reaction. The heating element control and temperature measurement system is connected to the heating element and is used to control the temperature of the heating element, provide a stable thermal field for the gas-liquid phase circulation unit, and display the temperature.

[0011] The circulating water acquisition and control unit includes a circulating water loop coil and a circulating water control and storage device. The circulating water loop coil is wrapped around the top of the gas-liquid phase circulating reaction tank near the tank opening to reduce the tank opening temperature and prevent the sealing gasket from deforming / melting. It provides cooling conditions for the tank body of the gas-liquid phase circulating reaction tank that is higher than the gas phase condensation collection cover, and creates a temperature difference to provide the temperature conditions for the gas phase to condense into the liquid phase. The circulating water control and storage device is connected to the circulating water loop coil through pipes III and IV, respectively. The outlet of the circulating water control and storage device is connected to the inlet of the circulating water loop coil through pipe IV, and the inlet of the circulating water control and storage device is connected to the outlet of the circulating water loop coil through pipe III, thereby realizing the circulation of water. The cooling efficiency is determined by controlling the water flow rate.

[0012] The product cooling unit includes a cooling tank and a cooling medium. The cooling medium is placed in the cooling tank. After the reaction in the gas-liquid phase circulation reactor is completed, the gas inlet control valve and the gas extraction control valve in the gas-liquid phase circulation unit are closed, the hard connection between the gas-liquid phase circulation unit and other units is disconnected, and the gas-liquid phase circulation reactor body is placed in the cooling medium, with the liquid level of the cooling medium higher than the position of the gas phase condensation collection cover.

[0013] Preferably, the sealing gasket is either a copper gasket or a fluororubber O-ring.

[0014] Preferably, the liquid phase reactor and the gas phase condensation collection cover are any one or a combination of two of high-purity quartz, high-purity graphite, and molybdenum, wherein the bottom end of the gas phase condensation collection cover has a downward-protruding arc-shaped feature, which facilitates the gas phase to fall back into the liquid phase after condensing in liquid form at the bottom end of the liquid phase collection cover.

[0015] The exhaust pipe and intake pipe in the gas-liquid phase circulation unit are connected to pipe I and pipe II of the negative pressure acquisition and control unit with KF type interfaces for easy disassembly and assembly.

[0016] Preferably, the gas-liquid phase circulating reaction vessel and the reaction vessel cover of the present invention are any one of high-purity quartz, stainless steel, and high-temperature alloy.

[0017] Preferably, the heat insulation layer of the present invention is any one of hard / soft graphite carbon felt, mullite insulating brick, or corundum brick.

[0018] Preferably, the flexible insulating sheet of the present invention is either high-purity graphite paper or high-purity nickel foil (thickness < 1.5 mm).

[0019] Preferably, the heating element can be any one of graphite, induction coil, resistance wire, or silicon molybdenum rod.

[0020] Preferably, the pressure gauge can be either a McElligott vacuum gauge or a Pirani vacuum gauge.

[0021] Preferably, the gas in the gas cylinder is a high-purity inert gas to maintain stable gas pressure in the gas-liquid phase circulation unit and prevent the raw materials from being oxidized.

[0022] Preferably, the cooling medium can be liquid nitrogen, a mixture of ice and water, or any type of water.

[0023] Compared with existing devices, this invention has the following advantages:

[0024] (1) The device described in this utility model has a simple mechanical structure, reasonable design, and simple operation. The raw material is heated into a liquid state by the heating element in the liquid phase reactor. Under the action of the negative pressure acquisition and control unit, the liquid material gradually vaporizes and enters the gas phase. When the gas phase substance encounters the gas phase condensation collection cover, it is condensed into a liquid state. The liquid substance drips back into the liquid phase reactor along the protrusion at the bottom of the gas phase condensation collection cover, forming a circulation of substances between the gas and liquid phases to achieve the final equilibrium state. After maintaining constant pressure and constant temperature in the gas-liquid phase circulation unit for a sufficient period of time under negative pressure, the inlet and outlet valves on both sides of the gas-liquid phase circulation unit are closed, and the gas-liquid phase circulation unit is placed in the cooling medium, allowing the substances remaining on the liquid phase reactor and the gas phase condensation collection cover to solidify instantly. After the experiment, the substances at the bottom of the liquid phase reactor and the substances on the side wall of the liquid phase reactor and the gas phase condensation collection cover are taken for analysis. Their composition is the gas-liquid phase equilibrium data of the raw material at the corresponding temperature and pressure.

[0025] (2) The device of this utility model is only equipped with a circulating water cooling device in the gas-liquid phase circulating reaction tank to protect the sealing gasket from being damaged and to ensure the airtightness of the equipment.

[0026] (3) The device of this utility model uses a heat insulation layer to surround the upper and lower ends of the liquid phase reactor and the condensation collection cover, which hinders the increase of the temperature gradient around the liquid phase reactor. This fundamentally avoids the problem that the condensation collection cover is in direct contact with the outside environment such as air / cooling water, resulting in a large temperature difference between the condensation collection cover and the liquid phase reactor. The temperature of the liquid phase reactor is too low, causing the gas phase substances to directly solidify in solid form at the bottom of the gas phase condensation collection cover, which cannot form a circulation balance between the gas and liquid phases. This achieves the normalization of the total gas and liquid phase composition based on the principle of gas-liquid phase balance. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0028] The labels in the diagram are as follows:

[0029] 1-Gas-liquid phase circulating reaction vessel, 2-Reaction vessel cover, 3-Sealing clamp, 4-Sealing gasket, 5-Reaction vessel support frame, 6-Insulation layer, 7-Liquid phase reactor, 8-Gas phase condensate collection cover, 9-Flexible isolation sheet, 10-Extraction pipe, 11-Inlet pipe, 12-Extraction control valve, 13-Inlet control valve, 14-Vacuum pump, 15-Pressure gauge, 16-Flow meter, 17-Gas cylinder, 18-Pipeline I, 19-Pipeline II, 20-Clamp I, 21-Clamp II, 22-Heating element, 23-Heating element control and temperature measurement system, 24-Circulating water loop coil, 25-Circulating water control and storage device, 26-Pipeline III, 27-Pipeline IV, 28-Outlet I, 29-Inlet, 30-Inlet, 31-Outlet II, 32-Cooling tank, 33-Cooling medium. Detailed Implementation

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0031] Example 1: As Figure 1 As shown, the device for acquiring alloy gas-liquid phase equilibrium data under negative pressure includes a gas-liquid phase circulation unit, a negative pressure acquisition and control unit, a heat source acquisition and control unit, a circulating water acquisition and control unit, and a product cooling unit.

[0032] The gas-liquid phase circulation unit includes a gas-liquid phase circulation reactor 1, a reactor cover 2, a sealing ring 3, a sealing gasket 4, a reactor support frame 5, a heat insulation layer 6, a liquid phase reactor 7, a gas phase condensate collection cover 8, a flexible isolation sheet 9, an extraction pipe 10, an inlet pipe 11, an extraction control valve 12, and an inlet control valve 13. The gas-liquid phase circulation reactor 1 is cylindrical. The reactor support frame 5 is installed below the tank body of the gas-liquid phase circulation reactor 1 to provide support for the gas-liquid phase circulation reactor 1 and maintain the structural stability of the gas-liquid phase circulation reactor 1 during operation. The flexible isolation sheet 9 is rolled into a cylindrical shape and fitted into the cylindrical gas-liquid phase circulation reactor 1. In this system, flexible insulating sheets 9 are tightly attached to the inner wall of the gas-liquid phase circulation reactor 1 to prevent metal vapor from directly contacting the inner wall, thus avoiding contamination and corrosion, and facilitating the reuse of the reactor. A cylindrical insulation layer 6 is placed at the bottom of the gas-liquid phase circulation reactor 1, with flexible insulating sheets 9 installed at the top and bottom of the lower insulation layer 6 to prevent metal vapor from entering the insulation layer 6, facilitating its reuse. A liquid phase reactor 7 containing metal / alloy raw materials is placed on the lower insulation layer 6, and a gas phase condensation collection cover 8 is placed at the opening of the liquid phase reactor 7. The bottom of the gas phase condensation collection cover 8 has a downward-protruding arc-shaped feature to facilitate the gas phase to liquid phase... The phase condenses and falls back to the liquid phase after being collected in the gas phase condensation collection cover 8; then, a heat insulation layer 6 is set above the horizontal plane of the gas phase condensation collection cover 8, and the isolation sheets 9 are placed on the top and bottom of the upper heat insulation layer 6 respectively; the sealing gasket 4 is placed in the groove at the mouth of the gas-liquid phase circulation reaction tank 1, and the reaction tank cover 2 with the same groove is placed above the gas-liquid phase circulation reaction tank 1, with the groove on the bottom surface of the reaction tank cover 2 in contact with the sealing gasket 4; the gas-liquid phase circulation reaction tank 1 and the reaction tank cover 2 are connected and sealed by the sealing gasket 4 and the sealing clamp 3, the exhaust port is located above the tank body of the gas-liquid phase circulation reaction tank 1, and an exhaust pipe 10 is installed at the exhaust port. A vacuum control valve 12 is installed on the 0 to control the pumping rate of the vacuum pump 14 in the negative pressure acquisition and control unit; the air inlet is located below the tank body of the gas-liquid phase circulation reaction tank 1, which is convenient to connect with the negative pressure acquisition and control unit. An air inlet pipe 11 is installed at the air inlet, and an air inlet control valve 13 is installed on the air inlet pipe 11. This is convenient to maintain the stable gas pressure in the gas-liquid phase circulation reaction tank after being connected with the negative pressure acquisition and control unit. At the same time, after closing the vacuum control valve 12 and the air inlet control valve 13, the entire gas-liquid phase circulation unit can maintain a constant pressure state for a short period of time, which is beneficial to disconnect the gas-liquid phase circulation unit from other units after the reaction is completed and enter the cooling unit for rapid cooling.

[0033] The negative pressure acquisition and control unit includes a vacuum pump 14, a pressure gauge 15, a flow meter 16, and a gas cylinder 17 containing inert gas. The negative pressure acquisition and control unit is connected to the gas-liquid phase circulation unit through pipe I 18 to obtain negative pressure conditions for the gas-liquid phase circulation unit. The vacuum pump 14 is connected to the exhaust pipe 10 of the gas-liquid phase circulation unit through pipe I 18, and the connection is fixed with clamp I 20 for easy disassembly. The pressure gauge 15 is directly connected to the vacuum pump 14 to read the gas pressure in the gas-liquid phase circulation unit. The gas cylinder 17 containing inert gas is connected to the inlet pipe 11 of the gas-liquid phase circulation unit through pipe II 19, and the connection is fixed with clamp II 21 to provide atmosphere protection for the gas-liquid phase circulation unit and prevent the raw materials from being oxidized. A flow meter 16 is installed on the gas cylinder 17 containing inert gas to control the gas flow rate from the gas cylinder 17 into pipe II 19, so as to stabilize the gas pressure in the gas-liquid phase circulation unit when used in conjunction with the vacuum pump 14.

[0034] The heat source acquisition and control unit includes a heating element 22 and a heating element control and temperature measurement system 23. The heating element 22 is located outside the gas-liquid phase circulation unit, surrounding the gas-liquid phase circulation reaction tank 1. The height of the heating zone of the heating element 22 is lower than the height of the gas phase condensation collection cover 8, providing a heat source for the melting of raw materials and the gas-liquid phase equilibrium reaction. The heating element control and temperature measurement system 23 is connected to the heating element 22 and is used to control the temperature of the heating element 22, provide a stable thermal field for the gas-liquid phase circulation unit, and display the temperature.

[0035] The circulating water acquisition and control unit includes a circulating water loop coil 24 and a circulating water control and storage device 25. The circulating water loop coil 24 is wrapped around the upper part of the gas-liquid phase circulating reaction tank 1 near the tank opening, reducing the temperature at the tank opening to prevent the sealing gasket 4 from deforming / melting. It provides cooling conditions for the tank part of the gas-liquid phase circulating reaction tank 1 that is higher than the gas phase condensation collection cover 8, and creates a temperature difference to provide temperature conditions for the gas phase to condense into the liquid phase. The circulating water control and storage device 25 is connected to the circulating water loop coil 24 through pipes III 26 and IV 27 respectively. The outlet I 28 of the circulating water control and storage device 25 is connected to the inlet 29 of the circulating water loop coil through pipe IV 27. The inlet 30 of the circulating water control and storage device is connected to the outlet II 31 of the circulating water loop coil through pipe III 26, realizing the circulation of water. The cooling efficiency is determined by controlling the water flow rate.

[0036] The product cooling unit includes a cooling tank 32 and a cooling medium 33. The cooling medium 33 is placed in the cooling tank 32. After the reaction in the gas-liquid phase circulation reactor 1 is completed, the gas inlet control valve 13 and the gas extraction control valve 12 in the gas-liquid phase circulation unit are closed, the hard connection between the gas-liquid phase circulation unit and other units is disconnected, and the tank body of the gas-liquid phase circulation reactor 1 is placed in the cooling medium 33. The liquid level of the cooling medium 33 is higher than the position of the gas phase condensation collection cover 8.

[0037] In this embodiment, both the gas-liquid phase circulating reaction vessel 1 and the reaction vessel cover 2 are made of high-purity quartz.

[0038] In this embodiment, the heat insulation layer 6 is a hard graphite carbon felt.

[0039] In this embodiment, the flexible insulating sheet is high-purity graphite paper.

[0040] In this embodiment, the sealing gasket 4 is an O-ring.

[0041] In this embodiment, the connection ends of the extraction pipe 10 and the inlet pipe 11 in the gas-liquid phase circulation unit with the pipe I 18 and pipe II 19 of the negative pressure acquisition and control unit are KF type interfaces, which are convenient for disassembly and assembly.

[0042] In this embodiment, the heating element 22 is a resistance wire.

[0043] In this embodiment, pressure gauge 15 is a McLaren vacuum gauge.

[0044] In this embodiment, the gas in cylinder 17 is high-purity argon, which maintains stable gas pressure in the gas-liquid phase circulation unit and prevents the raw materials from being oxidized.

[0045] In this embodiment, the cooling medium 33 is liquid nitrogen.

[0046] The method for determining the gas-liquid phase equilibrium using the apparatus for acquiring gas-liquid phase equilibrium data of a lead-tin binary alloy at 926℃ and 10Pa according to this embodiment is as follows:

[0047] S1: 20g of lead-tin binary alloy (Pb50%-Sn alloy) containing 30% lead is loaded into the liquid phase reactor 7. Then, the liquid phase reactor 7 is loaded into the gas-liquid phase circulation reaction tank 1. After installing the various accessories, the various units are connected.

[0048] S2: Open the exhaust control valve 12, the inlet control valve 13, and the vacuum pump 14 to introduce high-purity argon gas into the gas-liquid phase circulating reaction tank 1. Open the circulating water control and storage device 25. Set the temperature of the heating element control and temperature measurement system 23 to 926℃ to control the heating element 22 to reach the target temperature of 926℃. When the temperature of the heating element 22 reaches 926℃, control the flow meter 16 and the inlet control valve 13 to stabilize the gas pressure in the gas-liquid phase circulating reaction tank 1 at the target gas pressure of approximately 10Pa, allowing the raw materials in the gas-liquid phase circulating reaction tank 1 to flow smoothly. Under these conditions, the Pb50%-Sn alloy undergoes a gas-liquid phase reaction. After the preset reaction time is reached, the inlet control valve 13, the extraction control valve 12, and the vacuum pump 14 are closed. The hard connection between the gas-liquid phase circulation unit and other units is disconnected. The gas-liquid phase circulation reaction tank 1 is transferred to the cooling medium liquid nitrogen 33 for rapid cooling. After cooling is complete, the tank cover 2 of the reaction tank is opened, and the liquid phase reactor 7 and the gas phase condensation collection cover 8 are taken out. The substances contained at the bottom of the liquid phase reactor 7 and the substances on the side wall of the liquid phase reactor 7 and the gas phase condensation collection cover 8 are collected for analysis.

[0049] S3: The composition of the substance contained at the bottom of the liquid phase reactor 7 is the liquid phase composition, and the composition of the substance on the side wall of the liquid phase reactor 7 and the gas phase condensation collection cover 8 is the gas phase composition. Repeat the above steps, and set different heat preservation times according to the time in Table 1. If the relative average deviation of the gas phase and liquid phase compositions collected in three adjacent time periods is less than 0.2% at the same time, it is considered that the system has reached gas-liquid phase equilibrium in these three time periods. The average values ​​of the gas phase and liquid phase compositions in the three time periods can be taken as a pair of gas-liquid phase equilibrium data of the Pb-Sn alloy system under the conditions of 926℃ and 10Pa, that is, the gas phase composition is Sn: 84.975%, Pb: 15.025%; the liquid phase composition is Sn: 0.006%, Pb: 99.994%.

[0050] Table 1. Gas-liquid phase equilibrium test data of Pb50%-Sn alloy

[0051]

[0052]

[0053] Example 2: The structure of this example is the same as that of Example 1, except that the gas-liquid phase circulating reaction vessel 1 and the reaction vessel cover 2 in this example are both made of stainless steel.

[0054] In this embodiment, the heat insulation layer 6 is a mullite insulating brick.

[0055] In this embodiment, the flexible insulating sheet is a high-purity nickel foil (thickness < 1.5 mm).

[0056] In this embodiment, the sealing gasket 4 is a copper gasket.

[0057] In this embodiment, the heating element 22 is an induction coil.

[0058] In this embodiment, pressure gauge 15 is a Pirani vacuum gauge.

[0059] In this embodiment, the cooling medium 33 is an ice-water mixture.

[0060] The method for determining the gas-liquid phase equilibrium using the apparatus for acquiring gas-liquid phase equilibrium data of an aluminum-zinc binary alloy at 826℃ and 5Pa according to this embodiment is as follows:

[0061] S1: 40g of zinc-aluminum binary alloy (Zn30%-Al alloy) containing 30% zinc is loaded into the liquid phase reactor 7. Then, the liquid phase reactor 7 is loaded into the gas-liquid phase circulation reaction tank 1. After installing the various accessories, the various units are connected.

[0062] S2: Open the exhaust control valve 12, the inlet control valve 13, and the vacuum pump 14 to introduce high-purity argon gas into the gas-liquid phase circulating reaction tank 1. Open the circulating water control and storage device 25. Set the temperature of the heating element control and temperature measurement system 23 to 826℃ to control the heating element 22 to reach the target temperature of 826℃. When the temperature of the heating element 22 reaches 826℃, control the flow meter 16 and the inlet control valve 13 to stabilize the gas pressure in the gas-liquid phase circulating reaction tank 1 at the target gas pressure of about 5Pa, allowing the raw materials in the gas-liquid phase circulating reaction tank 1 to flow smoothly. Under these conditions, the Zn30%-Al alloy undergoes a gas-liquid phase reaction. After the preset reaction time is reached, the inlet control valve 13, the extraction control valve 12, and the vacuum pump 14 are closed. The hard connection between the gas-liquid phase circulation unit and other units is disconnected. The gas-liquid phase circulation reaction tank 1 is transferred to the cooling medium 33 and cooled rapidly. After cooling is completed, the tank cover 2 of the reaction tank is opened, and the liquid phase reactor 7 and the gas phase condensation collection cover 8 are taken out. The substances contained at the bottom of the liquid phase reactor 7 and the substances on the side wall of the liquid phase reactor 7 and the gas phase condensation collection cover 8 are collected for analysis.

[0063] S3: The composition of the substance contained at the bottom of the liquid phase reactor 7 is the liquid phase composition, and the composition of the substance on the side wall of the liquid phase reactor 7 and the gas phase condensation collection cover 8 is the gas phase composition. Repeat the above steps, and set different heat preservation times according to the time in Table 2. If the relative average deviation of the gas phase and liquid phase compositions collected in three adjacent time periods is less than 0.2% at the same time, it is considered that the system has reached gas-liquid phase equilibrium in these three time periods. The average values ​​of the gas phase and liquid phase compositions in the three time periods can be taken as a pair of gas-liquid phase equilibrium data of the Pb-Sn alloy system under the conditions of 826℃ and 5Pa, that is, the gas phase composition is Al: 99.996%, Zn: 0.004%; the liquid phase composition is Al: 0.001%, Zn: 99.999%.

[0064] Table 2. Gas-liquid phase equilibrium test data of Zn30%-Al alloy

[0065]

[0066] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. An apparatus for obtaining alloy gas-liquid equilibrium data at negative pressure, characterized by, It includes a gas-liquid phase circulation unit, a negative pressure acquisition and control unit, a heat source acquisition and control unit, a circulating water acquisition and control unit, and a product cooling unit; The gas-liquid phase circulation unit includes a gas-liquid phase circulation reactor (1), a reactor cover (2), a sealing ring (3), a sealing gasket (4), a reactor support frame (5), a heat insulation layer (6), a liquid phase reactor (7), a gas phase condensate collection cover (8), a flexible isolation sheet (9), an extraction pipe (10), an inlet pipe (11), an extraction control valve (12), and an inlet control valve (13). The gas-liquid phase circulation reactor (1) is cylindrical, and the reactor support frame (5) is installed below the tank body of the gas-liquid phase circulation reactor (1) to provide support for the gas-liquid phase circulation reactor (1), maintain the structural stability of the gas-liquid phase circulation reactor (1) during operation, and integrate the flexible isolation sheet. The insulating sheet (9) is rolled into a cylindrical shape and inserted into the tank body of the gas-liquid phase circulation reactor (1), so that the flexible insulating sheet (9) is tightly attached to the inner wall of the gas-liquid phase circulation reactor (1). The cylindrical heat insulation layer (6) is placed at the bottom of the gas-liquid phase circulation reactor (1), and the insulating sheet (9) is set at the top and bottom of the lower heat insulation layer (6) to prevent metal vapor from entering the heat insulation layer (6) and facilitate the reuse of the heat insulation layer (6). The liquid phase reactor (7) containing metal / alloy raw materials is placed on the lower heat insulation layer (6), and the gas phase condensation collection cover (8) is placed at the opening of the liquid phase reactor (7); then the gas phase condensation collection cover (8) is placed on the horizontal plane of the gas phase condensation collection cover (8). A heat insulation layer (6) is then installed on the upper part, and the isolation sheet (9) is placed on the top and bottom of the upper heat insulation layer (6) respectively; the sealing gasket (4) is placed at the groove of the gas-liquid phase circulation reaction tank (1), and the tank cover (2) with the same groove is placed above the gas-liquid phase circulation reaction tank (1), with the groove on the bottom surface of the tank cover (2) in contact with the sealing gasket (4); the gas-liquid phase circulation reaction tank (1) and the tank cover (2) are connected and sealed by the sealing gasket (4) and the sealing hoop (3), the exhaust port is located above the tank body of the gas-liquid phase circulation reaction tank (1), and an exhaust pipe (10) is installed at the exhaust port, with an exhaust control valve installed on the exhaust pipe (10). (12) is used to control the pumping rate of the vacuum pump (14) in the negative pressure acquisition and control unit; the inlet is located below the tank body of the gas-liquid phase circulation reaction tank (1) to facilitate connection with the negative pressure acquisition and control unit. An inlet pipe (11) is installed at the inlet, and an inlet control valve (13) is installed on the inlet pipe (11) to facilitate the maintenance of stable gas pressure in the gas-liquid phase circulation reaction tank after being connected with the negative pressure acquisition and control unit. At the same time, after closing the pumping control valve (12) and the inlet control valve (13), the entire gas-liquid phase circulation unit can maintain a constant pressure state for a short period of time, which is conducive to disconnecting the gas-liquid phase circulation unit from other units after the reaction is completed and entering the cooling unit for rapid cooling. The negative pressure acquisition and control unit includes a vacuum pump (14), a pressure gauge (15), a flow meter (16), and a gas cylinder (17) containing inert gas. The negative pressure acquisition and control unit is connected to the gas-liquid phase circulation unit through pipe I (18) to obtain negative pressure conditions for the gas-liquid phase circulation unit. The vacuum pump (14) is connected to the suction pipe (10) of the gas-liquid phase circulation unit through pipe I (18), and the connection is fixed with clamp I (20) for easy disassembly. The pressure gauge (15) is directly connected to the vacuum pump (14) and uses... The gas pressure in the gas-liquid phase circulation unit is read; the gas cylinder (17) containing inert gas is connected to the gas inlet pipe (11) of the gas-liquid phase circulation unit through pipe II (19), and the connection is fixed with clamp II (21) to provide atmosphere protection for the gas-liquid phase circulation unit and prevent the raw materials from being oxidized; a flow meter (16) is installed on the gas cylinder (17) containing inert gas to control the gas flow rate from the gas cylinder (17) into pipe II (19), so as to stabilize the gas pressure in the gas-liquid phase circulation unit when used in conjunction with the vacuum pump (14); The heat source acquisition and control unit includes a heating element (22) and a heating element control and temperature measurement system (23). The heating element (22) is located outside the gas-liquid phase circulation unit and surrounds the gas-liquid phase circulation reaction tank (1). The height of the heating zone of the heating element (22) is lower than the height of the gas phase condensation collection cover (8), providing a heat source for the melting of raw materials and the gas-liquid phase equilibrium reaction. The heating element control and temperature measurement system (23) is connected to the heating element (22) and is used to control the temperature of the heating element (22), provide a stable thermal field for the gas-liquid phase circulation unit, and display the temperature. The circulating water acquisition and control unit includes a circulating water loop coil (24) and a circulating water control and storage device (25). The circulating water loop coil (24) is wrapped around the upper part of the gas-liquid phase circulating reaction tank (1) near the tank opening to reduce the temperature of the tank opening and prevent the sealing gasket (4) from deforming / melting. It provides cooling conditions for the tank part of the gas-liquid phase circulating reaction tank (1) that is higher than the gas phase condensation collection cover (8) and creates a temperature difference to provide temperature conditions for the gas phase to condense into the liquid phase. The circulating water control and storage device (25) is connected to the circulating water loop coil (24) through pipes III (26) and IV (27) respectively. The outlet I (28) of the circulating water control and storage device (25) is connected to the inlet (29) of the circulating water loop coil through pipe IV (27). The inlet (30) of the circulating water control and storage device is connected to the outlet II (31) of the circulating water loop coil through pipe III (26) to realize the circulation of water. The cooling efficiency is determined by controlling the water flow rate. The product cooling unit includes a cooling tank (32) and a cooling medium (33). The cooling medium (33) is placed in the cooling tank (32). After the reaction in the gas-liquid phase circulation reactor (1) is completed, the gas inlet control valve (13) and the gas extraction control valve (12) in the gas-liquid phase circulation unit are closed. The hard connection between the gas-liquid phase circulation unit and other units is disconnected. The gas-liquid phase circulation reactor (1) is placed in the cooling medium (33). The liquid level of the cooling medium (33) is higher than the position of the gas phase condensation collection cover (8).

2. The apparatus for obtaining alloy gas-liquid equilibrium data at negative pressure according to claim 1, characterized in that: The sealing gasket (4) is either a copper gasket or a fluororubber O-ring.

3. The apparatus for obtaining alloy gas-liquid equilibrium data at negative pressure according to claim 1, wherein: The bottom of the gas phase condensation collection cover (8) has a downward protruding arc shape, which facilitates the gas phase to fall back into the liquid phase after condensing in the gas phase condensation collection cover (8) in liquid phase form.

4. The apparatus for obtaining alloy gas-liquid equilibrium data at negative pressure according to claim 1, wherein: The gas extraction pipe (10) and gas inlet pipe (11) in the gas-liquid phase circulation unit are connected to the pipe I (18) and pipe II (19) of the negative pressure acquisition and control unit with KF type interface, which is convenient for disassembly and assembly.

5. The apparatus for obtaining alloy gas-liquid equilibrium data at negative pressure according to claim 1, wherein: The heating element (22) can be any one of graphite, induction coil, resistance wire, or silicon molybdenum rod.

6. The apparatus for obtaining alloy gas-liquid equilibrium data at negative pressure according to claim 1, wherein: The pressure gauge (15) is either a McEllig vacuum gauge or a Pirani vacuum gauge.

7. The apparatus for obtaining alloy gas-liquid equilibrium data at negative pressure according to claim 1, wherein: The gas in the gas cylinder (17) is a high-purity inert gas, which maintains the stable gas pressure in the gas-liquid phase circulation unit and prevents the raw materials from being oxidized.

8. The apparatus for obtaining alloy gas-liquid equilibrium data at negative pressure according to claim 1, wherein: The cooling medium (33) is a mixture of liquid nitrogen and ice water, or any one of the following: water.

9. The apparatus for obtaining alloy gas-liquid equilibrium data at negative pressure according to claim 1, wherein: The heat insulation layer (6) is any one of hard / soft graphite carbon felt, mullite insulation brick, or corundum brick, and the flexible insulating sheet (9) is any one of high-purity graphite paper or high-purity nickel foil.

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