[0033] The present invention will be further described in detail below in conjunction with the drawings:
[0034] As shown in the figure, a vacuum atmosphere melting furnace for high-purity magnesium includes a control mechanism, a support frame 1 and a vertical double-layer shell arranged above the support frame 1, and the interior of the vertical double-layer shell A main heating assembly is provided. The vertical double-layer shell includes an inner shell 2 and an outer shell 3. A resistance wire 4 for auxiliary heating is wound on the outer surface of the side wall of the inner shell 2. The insulation material 5 is also filled between 2 and the outer shell 3. The main heating component and the resistance wire 4 are connected to the control mechanism. The top of the vertical double-layer shell is provided with a feed port 6 and a feed port 6 Set at the center of the top of the vertical double-layer shell, the feed port 6 is docked with the discharge port of the vacuum receiver 7 upstream of the process, and the feed port 6 and the vacuum receiver 7 of the vertical double-layer shell A vacuum valve 8 used to control the on-off of the discharge port is provided, and a heat shield valve 9 is also provided at the position below the vacuum valve 8 at the feed port 6, and the top of the vertical double-layer shell is also A vacuum assembly connection port 10, an inert gas inlet 11, an additive inlet 12, and a discharge port are provided. The vacuum assembly connection port 10 is connected to the external vacuum assembly 13, and the inert gas inlet 11 is connected to the external inert gas source 14 connection, the discharge port is set on one side inside the vertical double-layer shell, and a discharge pipe 15 is provided at the discharge port. One end of the discharge pipe 15 is placed on the liquid metal level inside the vertical double-layer shell Below, the other end of the discharge pipe 15 is connected to the vacuum magnesium alloy melting furnace or forming mold downstream of the process, and the discharge pipe 15 is also provided with an electric control valve 16 and a metering pump 17, in a vertical double-shell The body is also provided with internal multi-ring stirring components for stirring the internal materials, the vacuum valve 8, the heat shield valve 9, the vacuum assembly 13, the inert gas source 14, the electronic control valve 16, and the metering pump 17. And the internal multi-ring stirring components are connected with the control mechanism.
[0035] The main heating assembly includes a plurality of furnace heating tubes 18 vertically arranged inside the inner shell 2. The lower ends of the furnace heating tubes 18 extend from the inner bottom surface of the inner shell 2 to the outer shell 3 and are open. Structure, the furnace heating tube 18 is vertically welded to the lower bottom surface of the inner shell 2, and a plurality of furnace heating tubes 18 are evenly arranged inside the inner shell 2, as shown in the appendix figure 2 Shown. An inverted U-shaped heating element 19 is arranged inside each furnace heating tube 18, and a support cover 20 is also provided under each furnace heating tube 18, and the support cover 20 is provided There is a clamping device for fixing the heating element 19.
[0036] Preferably, the internal multi-ring agitator assembly is composed of a driving motor 21 and a multi-ring agitator. The driving motor 21 is arranged on the top of the vertical double-layer shell and connected to the control mechanism. The multi-ring agitator is arranged on the vertical Inside the double-layer shell, the multi-ring agitator includes a plurality of horizontal ring groups arranged in parallel up and down and a stirring shaft 22, each horizontal ring group includes a plurality of concentric rings 23, and the concentric rings 23 all avoid the main heating assembly in the vertical double-layer shell. A vertical fixing rod 24 is also connected between the concentric rings 23 that are parallel up and down. The upper end of the stirring shaft 22 extends from the vertical double-layer shell. Connected to the output shaft of the drive motor 21, the lower end of the stirring shaft 22 is connected to a horizontal ring group located at the top, and the horizontal ring group located at the top is also radially provided with a plurality of horizontal fixing rods 25. The horizontal fixing rod 25 is an integral structure, and a plurality of horizontal fixing rods 25 are evenly arranged along the circumference of the circle where they are located. The plurality of horizontal fixing rods 25 are all welded to the stirring shaft 22. The horizontal plane of the upper horizontal ring group is higher than the horizontal plane of the top of the main heating element.
[0037] When the heating tube in the vacuum atmosphere melting furnace for high-purity magnesium of the present invention is damaged, the following methods can be used for corresponding maintenance. First, remove the clamping device on the support cover, and then open the mounting flange (ie support cover) at the bottom of the heating tube in the furnace. At this time, the damaged heating element can be removed from the heating tube in the furnace and replaced accordingly. And overhaul. After the overhaul is completed, fix the mounting flange at the bottom of the heating tube in the furnace one by one, and fix the bottom end of the heating element (U-shaped silicon carbide rod) on the mounting flange through a clamping device.
[0038] The components in the vertical double-layer shell of the present invention are made of stainless steel, and the heating tube is also made of stainless steel. The upper part of the stainless steel tube is a blind head, and the lower part is welded to the bottom of the vacuum furnace body. The U silicon carbide heating element is from It is inserted into the furnace pot from bottom to top, and the cold end of the heating element is provided with a supporting cover-shaped baffle.
[0039] The vacuum atmosphere melting furnace for high-purity magnesium of the present invention has the following characteristics: 1. By opening the two vacuum valves on the upper part of the vertical double-layer shell, the magnesium crystals collected by the vacuum receiver can automatically fall into the stainless steel. The vertical double-layer shell can be realized. Before heating the vacuum atmosphere melting furnace, first close the vacuum valve connected to the vacuum receiver on the upper part of the furnace body, pass in inert gas, and then heat and melt high-purity magnesium, which is beneficial to reduce magnesium vapor To reduce unnecessary losses and avoid oxidation of high-purity metal magnesium; 3. Close the two vacuum valves on the top of the vertical double-layer shell to prevent inert gas from entering the vacuum receiver, causing waste; 4. Close the vertical The heat shield valve on the top of the double-layer shell can not only avoid the loss of heat in the furnace, but also prevent the heat in the furnace from entering the vacuum receiver upstream of the process, causing the magnesium crystals in the vacuum receiver to melt and build up on the inner wall of the vacuum receiver. Causes adhesion; 5. After the magnesium crystals are melted, the magnesium liquid can be transported to the vacuum atmosphere mixing furnace after the process through the metering pump, or can be directly transported to the magnesium product mold for molding; 6. The distinctive feature of the heating component is dual-system heating , That is, the heating system in the furnace formed by inserting the U-shaped heating element into the furnace tube is the main, and the electric furnace wire set on the inner surface of the insulation material around the furnace tank is used as a supplement to perform collaborative heating. The heating furnace tube is inserted into the furnace pot to heat the material, and the heat emitted by the heating element is directly transferred to the material through the furnace tube, which improves the thermal efficiency and realizes energy saving; 7. The internal heating method with the heating tube inserted into the furnace body is beneficial to increase heating Efficiency, energy saving, and shortening of the processing process cycle, reducing the production cost of the melting process. At the same time, the high heat transfer efficiency also prevents the inside and outside of the furnace body from having to endure a high temperature much higher than the melting temperature in order to reach the melting temperature of the internal materials , Thereby avoiding its own corrosion under high temperature conditions and pollution to metallic magnesium crystals, thereby ensuring high purity during the melting of magnesium crystals.
[0040] A melting process for a vacuum atmosphere melting furnace for high-purity magnesium includes the following steps:
[0041] a. The vacuum valve 8 and the heat shield valve 9 at the feed port 6 of the vertical double-layer shell are controlled to close by the control mechanism, and the external vacuum assembly 13 is controlled to face the inside of the vertical double-layer shell through the vacuum assembly connection port 10 Carry out vacuum treatment;
[0042] b. The vacuum valve 8 at the discharge port of the vacuum receiver 7 at the upstream of the process and the vacuum valve 8 and the heat shield valve 9 at the feed port 6 of the vertical double-layer shell are adjusted by the control mechanism to open, so that the vacuum valve in the vacuum receiver 7 High-purity metal magnesium crystals automatically fall into the vertical double-layer shell;
[0043] c. The vacuum valve 8 at the discharge port of the vacuum receiver 7 at the upstream of the process and the vacuum valve 8 and the heat shield valve 9 at the feed port 6 of the vertical double shell are closed by the control mechanism, and the inert gas outside is regulated. The gas source 14 fills the interior of the vertical double-layer shell with inert gas through the inert gas inlet 11 until the pressure inside the vertical double-layer shell is 0.1 MPa;
[0044] d. Heating the materials in the vertical double-layer shell through the control mechanism of the main heating component and the resistance wire 4, so that the temperature in the vertical double-layer shell is increased to 700-780℃, and the high-purity metal magnesium crystals are melted;
[0045] e. Through the control mechanism, the internal multi-ring mixing components are adjusted for material mixing for 3-5 minutes;
[0046] f. The electronic control valve 16 and the metering pump 17 are adjusted through the control mechanism, and the liquid magnesium sample is drawn from the vertical double-layer housing for testing, and whether it meets the requirements of high-purity magnesium. If it meets the requirements, the electronic control valve 16 and metering are controlled The pump 17 is turned on, and the magnesium liquid is pumped out through the discharge pipe 15 to the vacuum magnesium alloy melting furnace or forming mold downstream of the process for subsequent processing;
[0047] g. If it does not meet the requirements, it is adjusted by the control mechanism to add appropriate additives to the vertical double-layer shell through the additive inlet 12, and adjust the internal multi-ring stirring assembly for material mixing, so that the additives react with the excessive elements and precipitate in At the bottom of the furnace, control the internal multi-ring stirring assembly to close, keep the material in the vertical double-layer shell standing still for 5-10 minutes, after which, the electric control valve 16 and the metering pump 17 are controlled by the control mechanism to open, and the magnesium liquid is drawn out through the discharge pipe 15 To the vacuum magnesium alloy melting furnace or forming mold downstream of the process for subsequent processing.
[0048] The additive added in the process of the present invention is a trace element additive, and the trace element additive needs to be preheated before being fed through the additive inlet, and the preheating temperature is 200±20°C.
[0049] The various pumps and valves described are all electronic control components, which can be automatically controlled by a PLC-type control mechanism.
