Electromagnetic injection quantitative feeding device for inoculant and turbo-type inoculant mixing device comprising electromagnetic injection quantitative feeding device

Abstract

The invention discloses a nucleating agent electromagnetic injection quantitative feeding device and a turbo-type nucleating agent mixing device comprising the same. The nucleating agent electromagnetic injection quantitative feeding device comprises a gear feeding disc driven by a motor, a feeding hopper is connected to the upper portion of the gear feeding disc, an injection pipe is connected to the lower portion of the gear feeding disc, and a coil is wound outside the injection pipe; the injection pipe is a high-temperature-resistant non-metal pipe, the motor is provided with an encoder, and the motor and the coil are both connected with a controller. The motor drives the gear feeding disc to rotate, the controller controls the number of turns of rotation of the motor so as to control the adding amount of the inoculant, the electromagnetic coil is powered on to generate a magnetic field, the inoculant in the injection pipe is subjected to Lorentz force, the controller controls the electromagnetic coil to be powered off, the inoculant in the injection pipe is instantly injected out, and the inoculant is evenly dispersed at the moment of injection. Quantitative and uniform feeding of the inoculant is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of smelting and casting equipment, and in particular relates to an inoculant electromagnetic jet quantitative feeding device and a turbine type inoculant mixing device comprising the device. Background Art

[0002] Large-scale machine parts or equipment are of high quality and in great demand, and most of them are manufactured by casting. However, the microstructure of large-sized castings produced by conventional methods is uneven, which has a great impact on the quality of the product. The inoculant has the function of refining the matrix structure. In order to ensure the consistency of the product structure and the molding quality of the product, it is usually necessary to inoculate it during the pouring process of large castings. Inoculation treatment is to add a trace amount of inoculant to the liquid metal to promote its nucleation, inhibit its growth, and achieve grain refinement. The existing inoculant addition generally uses gravity to naturally fall into the molten metal. Since the inoculant is light and floats on the molten metal, it is not easy to mix evenly with the molten metal. When the screw conveying mechanism is used in the prior art to add the inoculant to the mixing container below the molten metal, the inoculant is added in strands and the dispersion is uneven. There are also some inoculant feeding mechanisms that combine the blowing device to blow the inoculant into the molten metal, which solves the dispersion problem of the inoculant, but the addition of gas is easy to affect the quality of the casting. Summary of the invention

[0003] In view of the above problems existing in the prior art, the present invention provides an electromagnetic spray quantitative feeding device for inoculant and a turbine-type inoculant mixing device comprising the device, which sprays the inoculant into the molten metal through electromagnetic action, thereby improving the uniform dispersion of the inoculant in the molten metal and preventing gas from entering the molten metal and affecting the quality of the casting.

[0004] The object of the present invention is achieved in the following manner: A quantitative feeding device for electromagnetic injection of inoculant comprises a gear feeding plate driven by a motor, a feeding hopper is connected above the gear feeding plate, a spray pipe is connected below the gear feeding plate, a coil is wound around the spray pipe, the spray pipe is a high temperature resistant non-metallic pipe, the motor is a motor with an encoder, and the motor and the coil are both connected to a controller.

[0005] A plurality of coils are wound around the injection pipe.

[0006] The injection tube is a ceramic tube.

[0007] A turbine-type inoculant mixing device comprises a pouring cup, a liquid guide tube, a contraction tube, a throat, a liquid outlet pipe and the above-mentioned electromagnetic jet quantitative feeding device, wherein the lower end of the contraction tube is connected to the injection pipe, the sprue of the pouring cup is connected to the contraction tube through the liquid guide tube, the lower part of the contraction tube is connected to the throat, and the lower part of the throat is connected to the liquid outlet pipe; a turbine device is arranged in the throat, and the turbine device consists of a central supporting cylindrical frame, a conical frame and turbine blades, the upper and lower parts of the central supporting cylindrical frame are connected to a conical frame, and the turbine blades are fixed to the outer wall of the central supporting cylindrical frame and to the inner wall of the throat.

[0008] The liquid outlet pipe is a diffusion pipe or a contraction pipe.

[0009] The inclination angle of the turbine blades is 30°≤α≤45°.

[0010] The inclined length of the turbine blade is 10mm≤L≤30mm.

[0011] The number of turbine blades is 6-12.

[0012] The electromagnetic injection quantitative feeding device for inoculant disclosed by the present invention is driven by a motor with an encoder to rotate a gear feeding disk, a controller controls the number of revolutions of the motor, thereby controlling the amount of inoculant added, the electromagnetic coil is energized to generate a magnetic field, the inoculant in the injection pipe is subjected to the Lorentz force, the controller controls the electromagnetic coil to be de-energized, and the inoculant in the injection pipe is instantly ejected, the ejected inoculant has good dispersibility, is more easily dispersed evenly in the molten metal, and quantitative and uniform feeding of the inoculant is achieved.

[0013] The turbine-type inoculant mixing device comprises the above-mentioned electromagnetic jet quantitative feeding device, and the injection pipe connected to the lower end of the contraction tube near the throat. The inoculant is sprayed into the contraction tube evenly and quantitatively to mix with the molten metal. Then, through the rotating vortex generated by the turbine device in the throat, the inoculant particles are mixed with the molten metal more evenly, and are fully melted and uniformly absorbed by the molten metal, so that the inoculant can fully play its role and improve the quality of the casting product. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of an inoculant electromagnetic jet quantitative feeding device.

[0015] Figure 2 It is a schematic diagram of the structure of a turbine inoculant mixing device.

[0016] Figure 3 It is a structural diagram of a pouring cup.

[0017] Figure 4 It is a schematic diagram of the structure of the throat.

[0018] Figure 5 It is a schematic diagram of the structure of the turbine device. DETAILED DESCRIPTION

[0019] In order to make the technical solution and advantages of the present invention more clearly presented, the present invention is described more clearly and in detail below with reference to the accompanying drawings and through specific embodiments. The described embodiments are only part of the embodiments designed by the present invention, not all embodiments.

[0020] like Figure 1 As shown, an electromagnetic injection quantitative feeding device for inoculant includes a gear feeding plate 11 driven by a motor, a feeding hopper 12 is connected above the gear feeding plate 11, a spray pipe 13 is connected below the gear feeding plate 11, a coil 14 is wound around the outside of the spray pipe 13, the spray pipe 13 is a high temperature resistant non-metallic tube, the motor is a motor with an encoder, and the motor and the coil 14 are both connected to a controller 15.

[0021] The motor drives the gear feeding plate 11 to rotate. The gap between each tooth of the gear feeding plate 11 and the shell is certain. The gap is the accommodating chamber of the inoculant. The inoculant added through the feeding hopper 12 rotates with the gear feeding plate in the accommodating chamber under the drive of the motor until it enters the injection pipe 13 below. The amount of inoculant corresponding to one rotation of the motor can be determined in advance. The number of rotations of the motor can be read through the encoder. The injection pipe regularly sprays the inoculant at a fixed time. The number of rotations of the motor during the interval between two injections can be known, and the amount of inoculant sprayed each time can be calculated. The controller 15 controls the number of rotations of the motor to control the amount of inoculant added. The electromagnetic coil is energized to generate a magnetic field. The ferrosilicon inoculant in the injection pipe is subjected to the Lorentz force and is accelerated in the injection pipe. When the inoculant is accelerated to a certain speed, the controller 15 controls the electromagnetic coil to be de-energized, and the inoculant in the injection pipe is instantly ejected. The inoculant is evenly dispersed at the moment of injection, and it is easier to be evenly dispersed in the molten metal, so as to achieve quantitative and uniform feeding of the inoculant.

[0022] Furthermore, multiple sets of coils 14 are wound around the injection pipe 13, and the multiple sets of coils 14 are connected in series, so that the generated Lorentz force is stronger, the inoculant is easier to be injected, the initial velocity is greater, the inoculant has better dispersion, and is easier to mix with the molten metal.

[0023] A further preferred solution is that the injection pipe 13 is made of a ceramic tube. Since the temperature of the molten steel used for casting is as high as over 1300°C, when the injection pipe injects the inoculant into the molten steel, the injection pipe contacts the molten steel. Therefore, the injection pipe needs to be resistant to high temperatures. Ceramic tubes are resistant to high temperatures of over 1500°C and are a good choice.

[0024] like Figure 2 , Figure 4 and Figure 5As shown, a turbine-type inoculant mixing device including an inoculant electromagnetic injection quantitative feeding device also includes a pouring cup 2, a liquid guide tube 3, a contraction tube 5, a throat 6, and a liquid outlet pipe 7. The lower end of the contraction tube 5 is connected to the injection pipe 13, and the straight pouring port of the pouring cup 2 is connected to the contraction tube 5 through the liquid guide tube 3. The lower part of the contraction tube 5 is connected to the throat 6, and the lower part of the throat 6 is connected to the liquid outlet pipe 7. A turbine device 60 is arranged in the throat 6. The turbine device 60 consists of a central supporting cylindrical frame 61, a conical frame 62 and a turbine blade 611. The central supporting cylindrical frame 61 is connected to a conical frame 62 at the upper and lower parts, and the turbine blade 611 is fixed to the outer wall of the central supporting cylindrical frame 61 and to the inner wall of the throat 6.

[0025] The conical structure of the conical frame 62 can guide the molten metal. In addition, the existence of the conical structure will disturb the streamline of the molten metal. When the molten metal flows through the conical frame 62, the streamline will be twisted, which will promote the formation of liquid vortex. At the same time, the conical frame 62 reduces the flow space of the liquid. The molten metal flows from the contraction tube 5, and the fluid will further accelerate the flow at the conical frame 62 to adapt to the gradually narrowing channel.

[0026] In a further preferred embodiment, the liquid outlet pipe 7 is a diffusion pipe with a smaller diameter at the top and a larger diameter at the bottom, or a contraction pipe with a larger diameter at the top and a smaller diameter at the bottom.

[0027] When the liquid outlet pipe 7 is a diffuser with a small diameter at the top and a large diameter at the bottom, the special structure composed of the contraction tube, the throat and the diffuser leads to the maximum flow rate at the throat, and the inoculant quickly passes through the throat and the turbine device to prevent the inoculant from adhering to the inner wall of the throat or the turbine device; at the same time, the special structure composed of the contraction tube, the throat and the diffuser will form a local negative pressure area at the throat position when the liquid flows through, and the negative pressure area can attract the entry of the inoculant and promote the mixing of the inoculant and the molten metal; this structure also helps to separate the bubbles from the liquid and remove the gas in the liquid, specifically: when the molten metal flows into the throat from the contraction tube, the liquid flow rate increases, the increase in flow rate will cause the pressure to decrease, and the gas will be released from the liquid to form bubbles. After the molten metal flows into the diffuser, the pressure is restored, and the bubbles will separate from the molten metal and rise to the negative pressure area, thereby discharging the bubbles out of the system and reducing the bubble content in the molten metal. After flowing through the turbine blades 611, when the molten metal continues to flow through the diffuser, the molten metal may slow down to adapt to the widened pipe. The change and gradient of the molten metal flow rate caused after passing through the contraction pipe and the liquid outlet pipe help to further promote the continued formation of vortices and the enhancement of the vortex effect.

[0028] When the liquid outlet pipe 7 is a contraction tube with a larger diameter at the top and a smaller diameter at the bottom, the flow velocity increases after the liquid passes through the first contraction tube, and then the flow velocity further increases after passing through the second contraction tube. The periodic change of the flow velocity will enhance the formation effect of the vortex and help mix the liquid and the inoculant.

[0029] In a further preferred embodiment, the pouring cup 2 is gourd-shaped. Figure 3 The pouring cup 2 has a solution pool and a sprue. The molten metal is poured into the pouring cup from the end away from the sprue. The gourd-shaped middle protrusion can filter the residue in the molten metal. The molten metal flows downward from the sprue into the liquid guide pipe 2.

[0030] The liquid guiding tube 3 and the shrink tube 5 are connected via a fastening ring 4, so as to achieve installation stability between the tubes during operation.

[0031] The inclination angle of the turbine blade is 30°≤α≤45°. The inclination angle can affect the angle of attack of the molten metal on the turbine blade, and further affect the flow state and velocity distribution of the molten metal, thereby adjusting the eddy current effect of the molten metal.

[0032] The inclined length of the turbine blade is 10mm≤L≤30mm. The increase in the inclined length of the turbine blade can increase the turbulence effect of the blade on the molten metal, thereby enhancing the eddy current intensity; in addition, the increase in the inclined length of the blade can adjust the diameter of the eddy current, and a longer blade will form a eddy current with a larger diameter to enhance the eddy current effect.

[0033] The number of turbine blades is 6-12. Changing the number of turbine blades will change the way the molten metal interacts with the blades. As the number of blades increases, the average tangential velocity of the fluid increases, and the fluid pressure gradient and swirl intensity attenuation rate decrease. Conversely, decreasing the number of blades will produce the opposite effect. Therefore, changing the number of turbine blades can adjust the vortex effect of the molten metal.

[0034] The lower end of the liquid outlet pipe 7 is connected to an outlet circular pipe 8, and the diameter of the outlet circular pipe 8 is adapted to the sprue, which is more conducive to the inoculant and the molten metal entering the sprue.

[0035] The solidification of the casting is slow in thick and large parts, and the grains have more time and space to grow, which makes the grains larger and easily forms large grain areas, thereby reducing the performance of the casting. At this time, it is necessary to add inoculants or the amount of inoculants to be added is more than other common locations. In the prior art, in this case, the addition of inoculants is generally based on the experience of technicians. The amount of inoculants added, the addition time and the end time are also dependent on experience, which makes it difficult to effectively guarantee the quality of the casting.

[0036] For this situation, the electromagnetic jet quantitative feeding device for inoculant disclosed in the present invention can realize the timed quantitative addition of inoculant. Specifically: for a casting of a known shape, at least two thermocouples are set in the casting cavity, and the positions of the thermocouples correspond to the two critical points of the thick and large parts of the casting and the slow solidification position. The first critical point is the starting point. When the molten metal is cast to the critical point, the temperature of the thermocouple rises instantly, and the thermocouple transmits the temperature signal to the controller. The controller controls the motor to rotate or accelerate to the set value, the coil is energized, and the electromagnetic jet quantitative feeding device for inoculant starts to work, and the inoculant is added or the amount of inoculant added increases; the second critical point is the end point. When the molten metal is cast to the critical point, the temperature of the thermocouple rises instantly, and the thermocouple transmits the signal to the controller. The controller controls the motor to stop rotating or decelerate to the set value, and the inoculant is stopped or the amount of inoculant added is restored to the normal level (i.e., the amount added before the first critical point), so as to realize the timed quantitative feeding of the inoculant. The added inoculant can promote the uniformity of crystal nucleus formation and growth, improve the effect of grain refinement, avoid the formation of coarse tissue in these locations, and ensure a more uniform organizational structure for the entire casting.

[0037] The above is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several changes and improvements can be made without departing from the overall concept of the present invention, which should also be regarded as the scope of protection of the present invention.

Claims

1. An electromagnetic injection quantitative feeding device for inoculant, characterized in that: The invention comprises a gear feeding plate (11) driven by a motor, wherein the gear feeding plate (11) is connected to a feeding hopper (12) above, and a spray pipe (13) is connected to the gear feeding plate (11) below, wherein a coil (14) is wound around the spray pipe (13), wherein the spray pipe (13) is a high temperature resistant non-metallic pipe, and the motor is a motor with an encoder, and the motor and the coil are both connected to a controller.

2. The inoculant electromagnetic jet quantitative feeding device according to claim 1 is characterized in that: A plurality of coils (14) are wound around the injection pipe (13).

3. The inoculant electromagnetic jet quantitative feeding device according to claim 1 is characterized in that: The injection pipe (13) is a ceramic pipe.

4. A turbine inoculant mixing device, characterized in that: It comprises a pouring cup (2), a liquid guide tube (3), a contraction tube (5), a throat (6), a liquid outlet pipe (7) and the electromagnetic jet quantitative feeding device as claimed in claim 1 or 3, wherein the lower end of the contraction tube (5) is connected to the injection pipe (13), the straight pouring port of the pouring cup (2) is connected to the contraction tube (5) through the liquid guide tube (3), the lower part of the contraction tube (5) is connected to the throat (6), and the lower part of the throat (6) is connected to the liquid outlet pipe (7); a turbine device (60) is arranged in the throat (6), the turbine device (60) is composed of a central supporting cylindrical frame (61), a conical frame (62) and a turbine blade (611), the upper and lower parts of the central supporting cylindrical frame (61) are connected to a conical frame (62), and the turbine blade (611) is fixed to the outer wall of the central supporting cylindrical frame (61) and fixed to the inner wall of the throat (6).

5. The turbine inoculant mixing device according to claim 4, characterized in that: The liquid outlet pipe (7) is a diffusion pipe or a contraction pipe.

6. The turbine inoculant mixing device according to claim 1, characterized in that: The inclination angle of the turbine blade (611) is 30°≤α≤45°.

7. The turbine inoculant mixing device according to claim 1, characterized in that: The inclined length of the turbine blade (611) is 10 mm ≤ L ≤ 30 mm.

8. The turbine inoculant mixing device according to claim 1, characterized in that: The number of turbine blades (611) is 6-12.

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