Patent Description:
Smelting involves a process of melting a primary metal charged into a melting furnace. During the melting process, components for conditioning the molten metal, such as feedstock and compounds, are added to the furnace to reduce impurities in the molten metal and remove those substances affecting quality of metal products.

Feedstock is generally added by being directly charged into the furnace. A feedstock with a density lower than that of the molten metal will float on top of the molten metal, while a feedstock with a density higher than that of the molten metal will sink to the bottom the molten metal. Since the molten metal in the melting furnace is in a stationary state, the melted feedstock likely concentrates on top or at bottom of the molten metal, and this inhomogeneous composition distribution would cause quality defects in the products. Therefore, after a feedstock is charged, it is needed to stir the molten metal such that composition of the feedstock is homogeneously distributed in the molten metal. However, during the stirring process, a vortex likely occurs and impurities deposited in the bottom layer are also likely diffused; therefore, the stirring should not be intense. At present, the stirring is generally done manually with an iron ladle. Due to the high-temperature work condition, high labor intensity, and easy occurrence of melt splashing, stirring is highly risky to operators. Manual stirring further has drawbacks such as inaccurate control of stirring intensity and insufficient stirring in some areas of the molten metal, finally affecting product quality.

<CIT> describes a method and an apparatus for producing a composite material. It relates to a method and an apparatus where a dispersion of reinforcing particles into metals. Particularly it relates to a mixing of two different materials and solutions for them to correctly bond to one another by pushing a material out of passages that are submerged and connected a hollow rotor into liquid metal. Since the centrifugal force is so high no agglomerations of material are being created and a uniform distribution is achieved. <CIT> describes a stirring device. The stirring device includes a rotating unit, an aeration unit and a feeding unit. The stirring device is configured to allow a mixing of a composite material into a liquid aluminum. Through an inner flow passage inert gas is pushed directly into a liquid aluminum through an agitating member. Through an outer flow channel that is wrapped around the inner flow passage silicon carbide is pushed by the inert gas into the liquid aluminum above the agitating member.

To overcome the above and other drawbacks of conventional technologies, embodiments of the disclosure provide a metal melting furnace including a stirring device, which replaces manual stirring with automatic stirring to realize homogeneous distribution of feedstock in molten metal, thereby mitigating labor intensity of operators and effectively controlling stirring duration and stirring range.

To overcome the drawbacks, a metal melting furnace including a stirring device according to Claim <NUM> is proposed. Further embodiments of the invention are specified in dependent claims <NUM>-<NUM>.

The disclosure offers the following benefits:.

A metal furnace including a stirring device according to the disclosure is provided with a stirring disc. During the smelting process, the feedstock charged into the molten metal can be held on the stirring disc via the feedstock holding portion, such that the feedstock, together with the stirring disc, may be immersed into the molten metal, without floating on top of the molten metal, which prevents oxidization reaction and abnormal loss of the feedstock due to being exposed to the air in a high-temperature environment; in addition, this design can also increase oxygen content in the molten metal; al the feedstock does not float on top of the molten metal or sink to the bottom of the molten metal, preventing inhomogeneous composition distribution of the molten metal. Driven by the drive device, the stirring disc may move up and down in the molten metal, which enhances homogeneity of the feedstock in the molten metal, thereby ensuring consistent quality of metal products; in addition, this design eliminates a need of manual stirring, reduces labor intensity of operators, and lowers risks. Moreover, automated stirring offers a larger stirring range than manual stirring and avoids the quality issue arising from insufficient stirring in some areas of the molten metal, which also gives a higher stirring efficiency than manual operation and reduces the duration of stirring operation.

The vertically through openings allow for the molten metal to pass through the stirring disc, which reduces the resistance subjected to the stirring disc when moving up and down in the molten metal and avoids extensive diffusion of bottom-layer impurities caused by the induced vortex of the molten metal, such that the molten metal may flow gently during up-and-down movement of the stirring disc. Generally, extensive impurities would be deposited at the bottom layer of molten metal; the molten metal at the bottom layer does not participate in the casting process, but always resides in the melting furnace till the furnace is scrapped. In the disclosure, since the stirring disc does not induce extensive diffusion of the impurities during the feedstock melting process, the quality of the molten metal available for casting in the chamber will not be affected; in addition, it takes less time for letting the stirred molten metal stand till the impurities settle, without incurring unnecessary energy waste; and meanwhile the disclosure may enhance smelting efficiency of the molten metal and thus improve productivity.

Furthermore, the feedstock holding portion comprises a cavity for accommodating the feedstock, the feedstock inlet communicates with the cavity, and the openings comprise a first opening provided in the top wall of the cavity and a second opening provided in the bottom wall of the cavity, the first opening and the second opening having a size smaller than that of the feedstock. The feedstock is accommodated in the cavity, during the stirring process, the molten metal may access the cavity via the first opening and the second opening, where it is sufficiently mixed with the feedstock. Then, the molten metal mixed with the feedstock composition flows out of the cavity via the first opening and the second opening to be mixed with external molten metal, whereby the feedstock is sufficiently distributed in the molten metal. Since the sizes of the first opening and the second opening are smaller than that of the feedstock, the feedstock can be kept in the chamber; with the feedstock being melt, its size will be shrunk to be smaller than that of the first opening and the second opening, such that it likely escapes from the stirring disc via the first opening and the second opening; however, since the shrunk size of the feedstock is very small, even if it floats on top of the molten melt or sinks to the bottom of the molten melt, it has little impact on the composition of molten metal; in addition, if the molten metal has a higher melting point, the feedstock will be completely melted before floating on top of the molten metal or sinking to the bottom of the molten metal.

Furthermore, the bottom wall of the cavity has a height gradually reduced from the feedstock inlet towards the direction of the first opening. The feedstock charged into the cavity via the feedstock inlet may move till beneath the first opening along the bottom wall of the cavity. The feedstock entering the cavity via the feedstock inlet may move along the bottom wall under the guide of the bottom wall, thereby falling below the first opening. If the feedstock has a density greater than the molten metal, the feedstock can be kept at the bottom wall of the cavity without exiting the stirring disc via the feedstock inlet during up-and-down movement of the stirring disc; if the feedstock has a density smaller than that of the molten metal, the feedstock will float up to abut against the top wall of the cavity after the stirring disc is immersed in the molten metal, in which case since the floating feedstock is located beneath the first opening, it does not easily escape from the stirring disc via the feedstock inlet.

Furthermore, the feedstock holding portion further comprises a baffle plate, the baffle plate being formed as extending from the cavity between the feedstock inlet and the first opening towards the bottom wall of the cavity, both sides of the baffle plate being connected to sidewalls of the cavity. In a case that the density of the feedstock is lower than that of the molten metal, the feedstock will move upward after the stirring disc is immersed in the molten metal; the baffle plate serves to baffle the upward floating feedstock and limit the feedstock from moving towards the feedstock inlet. The feedstock before floating upward is located in the cavity offset from the feedstock inlet; since the surface of the molten metal flows gently, the feedstock's upward floating follows a substantially vertically linear path, such that it does not easily move towards the direction of the feedstock inlet during the upward floating process; even if the upward floating feedstock has a tendency of moving towards the feedstock inlet, it will be baffled and stopped by the lower end of the baffle plate after floating upward a certain height, thereby avoiding the circumstance that the feedstock is separated from the stirring disc during the process of immersing the stirring disc in the molten metal. In addition, since both sides of the baffle plate are connected to the sidewall of the cavity, the feedstock cannot bypass the baffle plate to move towards the feedstock inlet.

Furthermore, the baffle plate tilts from top to bottom towards the direction of the feedstock inlet; the tilting design of the baffle plate improves the feedstock baffling range of the lower end of the baffle plate, which may thus improve reliability.

Furthermore, the stirring disc further comprises an annular boss disposed at a bottom portion of the disc body, an outer-ring wall of the annular boss being connected to a periphery of the disc body, the lower end of the annular boss being tapered from top to bottom. The annular boss protrudes from the bottom portion of the disc body, such that during the process of immersing the stirring disc in the molten metal, the annular boss first accesses the molten metal prior to the disc body; since the lower end of the annular boss is tapered, the annular boss, during the process of being immersed in the molten metal, generates a reduced intensity in stirring the molten metal, without incurring an intensive fluctuation in the molten metal. The outer-ring wall of the annular boss is connected to the periphery of the disc body, such that the periphery of the disc body does not protrude from the annular boss, which reduces the molten metal stirring magnitude at its peripheral portion during the process of immersing the disc body in the molten metal, avoiding formation of a vortex around the stirring disc.

Furthermore, the openings further comprise a third opening, the third opening being disposed at a portion of the disc body corresponding to a circular space enclosed by the annular boss. When the annular boss is completely immersed into the molten metal, a lower surface, corresponding to the circular space, on the disc body will be exposed to the molten metal; provision of the third opening allows for the gas in the circular space to be discharged via the third opening during the downward-moving process of the stirring disc and also allows for the molten metal to pass through the third opening, thereby reducing the molten metal stirring magnitude of the stirring disc. In addition, provision of the circular space can also reduce the overall weight of the stirring disc, thereby reducing the load of the drive device.

Furthermore, the circular space is flared from top to bottom. The sidewall of the circular space serves to guide the molten metal, which can reduce the molten metal stirring magnitude of the top wall of the circular space.

Furthermore, a height of an upper surface of the disc body is gradually reduced from the stirring rod to the periphery of the disc body. The upper surface of the disc body serves to guide the molten metal such that when the stirring disc moves upward, the molten metal above the stirring disc may be guided by the upper surface of the disc body to flow towards the periphery of the disc body, which can reduce the magnitude of stirring the molten metal, and during the process of the stirring disc exiting the molten metal, the molten metal left on the upper surface of the stirring disc may be reduced so as to prevent the cooled molten metal from blocking the openings.

Furthermore, the metal melting furnace further comprises an automatic charger configured to replenish the feedstock to the feedstock holding portion. The automatic charger allows for automatic replenishment of feedstock to the stirring disc, which eliminates manual charging, thereby enhancing operation safety as well as operation efficiency.

Furthermore, the automatic charger comprises an outlet path, a feedstock reservoir communicating with the outlet path, and a pusher, the pusher being configured to push the feedstock on the outlet path such that the feedstock falls onto the feedstock holding portion. The feedstock reservoir communicates with the outlet path, such that the feedstock in the feedstock reservoir can access the outlet path; the pusher may push the feedstock in the outlet path such that the feedstock is pushed out of the outlet path and falls on the feedstock holding portion, thereby realizing automatic replenishment of the feedstock.

Furthermore, the pusher comprises a base, two pushing arms rotatably mounted on the base, and a pushing ram configured to push the base, and the automatic charger further comprises a slide groove which communicates with the outlet path such that the pusher enters/exits the outlet path, the feedstock reservoir being disposed above the outlet path, the feedstock reservoir communicating with the outlet path via a feed path. The pushing ram may push the base to drive the pushing arms to move; the pushing arms may extend out of the slide groove along with the base to access the outlet path; during the pushing process, the pushing arms can push the feedstock in the outlet path such that the feedstock moves forward and falls onto the feedstock holding portion from the outlet path, and the feedstock in the feedstock reservoir can access the outlet path along the outlet path, whereby replenishment of the feedstock in the outlet path is completed.

Furthermore, the two pushing arms are folded to push the feedstock, and the two pushing arms, when being folded, enclose an avoidance hole, the feedstock in the feed path passing through the avoidance hole to enter the outlet path; when the pusher moves backward, the two push arms are deployed so as to be separated from the feedstock in the avoidance hole. During the pushing process, the pushing arms are kept folded so as to push the feedstock in the outlet path; since the two folded pushing arms can enclose an avoidance hole, the feedstock in the feed path can pass through the avoidance hole and then enters the outlet path, whereby replenishment of the feedstock in the outlet path is completed; during return movement of the pusher, the two pushing arms are deployed to be separated from the feedstock, such that the pushing arms may be retracted into the slide groove.

Furthermore, upon pushing the feedstock, an end portion of the pushing ram extends out from the base till between the two pushing arms to stop rotation of the pushing arms; when the pusher moves backward, the end portion of the pushing ram is retracted in the base; after the feedstock pushes the two pushing arms to be deployed, the pusher is separated from the feedstock; an avoidance groove for avoiding the pushing arms is provided at a sidewall of the outlet path, a sidewall of the slide groove being provided with a guide groove connected to the avoidance groove; and in a backward movement direction of the pusher, the guide groove is shrunk to push the two pushing arms to be folded. The end portion of the pushing ram may extend out of the base during the pushing process. The end portion of the pushing ram is disposed between the two pushing arms so as to be capable of stopping the two pushing arms, whereby rotation of the two pushing arms is limited such that the two pushing arms can be kept in a folded state so as to push the feedstock to move. Upon return movement, since the end portion of the pushing ram has been retracted in the base, rotation of the two pushing arms is not limited, while the feedstock cannot access the slide groove; therefore, during return movement of the pusher, a mutually compressive force occurs between the pushing arms and the feedstock, where the compressive force causes the two pushing arms to be separated and deployed, thereby being separated from the feedstock. The avoidance groove may provide a space for deployment of the pushing arms. The guide groove is connected to the avoidance groove, such that the deployed pushing arms may enter the guide groove from the avoidance groove. As the base moves, the pushing arms will access the inner wall of the guide groove and be gradually pushed by the inner wall of the guide groove, such that the two pushing arms move close to each other to be refolded.

Embodiments of the disclosure provide a further metal melting furnace including a stirring device. During the smelting process, the feedstock charged in the molten metal may be held on the feedstock holding portion, such that the feedstock may be immersed into the molten metal along with the feedstock holding portion without floating on top of the molten metal, which prevents the feedstock from being exposed to the air in the high-temperature environment and oxidized to cause abnormal loss of the feedstock; in addition, the oxygen content in the molten metal may also increase; the feedstock does not flow on top of the molten metal or sink to the bottom of the molten metal, without causing inhomogeneous distribution of the composition of the molten metal. Driven by the drive device, the stirring rod may drive the impeller and the feedstock holding portion to rotate to stir the molten metal, which may improve homogeneity of the feedstock in the molten metal to ensure consistent quality of the metal products; in addition, it eliminates a need for manual stirring, which reduces labor intensity of operators and lowers risks. Moreover, the automatic stirring offers a larger stirring range than manual stirring, preventing quality defects due to insufficient stirring of some areas in the molten metal; in addition, its stirring efficiency is also higher than the manual operation with reduced stirring duration.

Furthermore, the feedstock holding portion comprises a housing, a cavity defined by the housing, and a through hole which is provided on the housing and communicates with the cavity, the through hole having a size smaller than that of the feedstock. The feedstock is accommodated in the cavity; during the stirring process, the molten metal may access the cavity via the through hole so as be sufficiently mixed with the feedstock; then, the molten metal mixed with the feedstock composition flows out of the cavity via the through hole so as to be mixed with the external molten metal; in this way, the feedstock is homogeneously distributed in the molten metal. Since the size of the through hole is smaller than that of the feedstock, the feedstock can be kept in the cavity. As the feedstock is melted, its size will be shrunk to be smaller than that of the through hole, such that the feedstock likely exits the feedstock holding portion via the through hole; however, since the feedstock has been significantly shrunk, even if it floats on top of the molten metal or sinks to the bottom of the molten metal, there would have little impact on the composition of the molten metal; and if the molten metal has a high melting point, the feedstock would be completely melted before floating on top of the molten metal or sinking to bottom of the molten metal.

Furthermore, the cavity comprises an inlet zone and a melting zone; a feedstock inlet communicating with the cavity so as to charge the feedstock to the inlet zone is further provided on the housing; a feedstock guide portion for guiding the feedstock from the inlet zone to the melting zone is provided at a bottom wall of the cavity. The feedstock inlet communicates with the cavity so as to replenish the feedstock to the feedstock holding portion after the feedstock is used up, the feedstock entering the inlet zone via the feedstock inlet; the feedstock is immersed into the melting zone from the inlet zone under the guide by the feedstock guide portion, thereby reducing the odds of the feedstock exiting the feedstock holding portion via the feedstock inlet.

Furthermore, in a rotating direction of the stirring rod, a front end of the impeller is higher than a rear end thereof so as to guide the molten metal to flow from top to bottom during rotating of the impeller. During the stirring process, the impeller can guide the molten metal to flow from top to bottom; in this way, the molten metal in the bottom layer will not be brought to move upward, without causing diffusion of the impurities in the bottom layer of the molten metal and deteriorating product quality.

Furthermore, the impeller is disposed below the feedstock holding portion so as to guide the molten metal carrying feedstock composition to move downward during stirring. The feedstock holding portion is disposed above the impeller; the molten feedstock is distributed in the top-layer molten metal; while the impeller can guide the molten metal downward; thus, the impeller can guide the top-layer molten metal including extensive feedstock composition to move downward, thereby homogenizing feedstock distribution.

The above and other features and benefits of the disclosure will be described in more detail through example embodiments with reference to the accompanying drawings.

Hereinafter, the disclosure will be described in further detail with reference to the accompanying drawings:.

Hereinafter, the technical solutions of the disclosure will be explained and described through example embodiments with reference to the accompanying drawings. It is noted that the example embodiments described infra are only preferred examples, not the entirety of the embodiments of the disclosure. All other embodiments derived by those skilled in the art based on the example embodiments without exercise of inventive efforts shall fall within the scope of protection of the disclosure.

The terms "exemplary" and "some example embodiments" appearing infra mean "used as an example, an example implementation, or an illustration," and any embodiment described in an "exemplary" way is not necessarily interpreted as preferred over or better than other example implementations. To better illustrate the disclosure, various details are provided in the example embodiments below, and those skilled in the art shall appreciate that the disclosure can also be implemented without some details thereof.

Referring to <FIG>, embodiments of the disclosure provide a metal melting furnace including a stirring device, comprising: a furnace body <NUM> and the stirring device, the furnace body <NUM> defining a chamber <NUM> for accommodating molten metal, the stirring device being configured to sufficiently mix feedstock charged into the chamber <NUM> with the molten metal such that the feedstock is homogeneously distributed in the molten metal. The stirring device comprises a stirring disc <NUM>, a stirring rod <NUM> connected to the stirring disc <NUM>, and a drive device <NUM> in drive connection to the stirring rod <NUM>, the stirring disc <NUM> having a feedstock holding portion <NUM>, the drive device <NUM> being configurable to drive the stirring rod <NUM> to move up and down such that the stirring disc <NUM> is immersed in or lifted out of the molten metal in the chamber <NUM>, a plurality of vertically through opening being provided on the stirring disc <NUM> such that during the stirring process, the feedstock in the feedstock holding portion <NUM>, along with the stirring disc <NUM>, is immersed in the molten metal in which the feedstock is melted, the drive device <NUM> being configured to drive the stirring rod <NUM> to lift reciprocally.

During the smelting process of the metal melting furnace including a stirring device, the feedstock charged into the molten metal can be held on the stirring disc <NUM> via the feedstock holding portion <NUM>, such that the feedstock, along with the stirring disc <NUM>, may be immersed into the molten metal, without floating on top of the molten metal, which prevents oxidization reaction and abnormal loss of the feedstock due to being exposed to the air in a high-temperature environment; in addition, this design can also increase oxygen content in the molten metal, and prevents inhomogeneous composition distribution of the molten metal due to floating of the feedstock on top of the molten metal or sinking of the feedstock to the bottom of the molten metal. The stirring rod <NUM> is configurable to lift reciprocally under the action of the drive device <NUM>, such that the stirring disc <NUM> moves up and down in the molten metal, which may enhance homogeneity of the feedstock in the molten metal, thereby ensuring consistent quality of metal products; in addition, this design eliminates a need of manual stirring, reduces labor intensity of operators, and lowers risks. Moreover, automated stirring offers a larger stirring range than manual stirring and avoids the quality issue arising from insufficient stirring in some areas of the molten metal, which also gives a higher stirring efficiency than manual operation and reduces the duration of stirring operation.

The vertically through openings allow for the molten metal to pass through the stirring disc <NUM>, which reduces the resistance subjected to the stirring disc <NUM> when moving up and down in the molten metal and avoids extensive diffusion of bottom-layer impurities caused by the induced vortex of the molten metal, such that the molten metal may flow gently during up-and-down movement of the stirring disc <NUM>. Generally, extensive impurities would be deposited at the bottom layer of molten metal; the molten metal at the bottom layer does not participate in the casting process, but always resides in the melting furnace till the furnace is scrapped. In the disclosure, since the stirring disc <NUM> does not induce extensive diffusion of the impurities during the feedstock melting process, the quality of the molten metal available for casting in the chamber <NUM> will not be affected; in addition, it takes less time for letting the stirred molten metal stand till the impurities settle, without incurring unnecessary energy waste (i.e., the energy consumed for holding the molten state of the metal during the standing duration); and meanwhile, the disclosure may enhance smelting efficiency of the molten metal and thus improve productivity.

In the disclosure, the molten metal refers to molten copper, and the feedstock refers to zinc; alternatively, the feedstock may be other elements or compounds, and the molten metal may also be molten iron, molten steel, etc..

Since the molten metal is rapidly cooled down when being exposed to the air, it is improper to design a movable part on the stirring disc <NUM> to hold the feedstock; in addition, after the feedstock size is shrunk, it becomes unholdable. Referring to <FIG>, based on the example embodiment described supra, in one implementation of the disclosure, the feedstock holding portion <NUM> defines a cavity <NUM> for accommodating the feedstock, and the openings comprise a first opening <NUM> provided in the top wall of the cavity <NUM> and a second opening <NUM> provided in the bottom wall of the cavity <NUM>, the first opening <NUM> and the second opening <NUM> having a size smaller than that of the feedstock; during the stirring process, the molten metal may access the cavity <NUM> via the first opening <NUM> and the second opening <NUM>, where it is sufficiently mixed with the feedstock. Then, the molten metal mixed with the feedstock composition flows out of the cavity <NUM> via the first opening <NUM> and the second opening <NUM> to be mixed with external molten metal, whereby the feedstock is sufficiently distributed in the molten metal. Since the sizes of the first opening <NUM> and the second opening <NUM> are smaller than that of the feedstock, the feedstock can be kept in the cavity <NUM>; with the feedstock being melt, its size is shrunk to be smaller than that of the first opening <NUM> and the second opening <NUM>, such that it likely escapes from the stirring disc <NUM> via the first opening <NUM> and the second opening <NUM>; however, since the shrunk size of the feedstock is very small, even if they float on top of the molten melt or sink to the bottom of the molten melt, it has little impact on the composition of molten metal; in addition, if the molten metal has a higher melting point, the feedstock will be completely melted before floating on top of the molten metal or sinking to the bottom of the molten metal.

In addition, a feedstock inlet <NUM> in communication with the cavity <NUM> is provided on an upper surface of the stirring disc <NUM>, where the feedstock may be replenished into the cavity <NUM> via the feedstock inlet <NUM>. The size of the feedstock inlet <NUM> is slightly greater than that of the feedstock. In an example implementation, a ratio of the size of the feedstock inlet <NUM> to the size of the feedstock ranges from <NUM>/<NUM> to <NUM>/<NUM>. With this design, it becomes more difficult for the feedstock to leave the cavity <NUM> via the feedstock inlet <NUM>.

Furthermore, the bottom wall of the cavity <NUM> has a height gradually reduced from the feedstock inlet <NUM> towards the direction of the first opening <NUM>. In the disclosure, the feedstock is a spherical object, which, after being charged into the cavity <NUM> via the feedstock inlet <NUM>, may move, under its own gravity, till beneath the first opening <NUM> along the bottom wall of the cavity <NUM>; in this way, if the feedstock has a density greater than the molten metal, the feedstock can be kept at the bottom wall of the cavity <NUM> without exiting the stirring disc <NUM> via the feedstock inlet <NUM> during up-and-down movement of the stirring disc <NUM>; if the feedstock has a density smaller than that of the molten metal, the feedstock will float up to abut against the top wall of the cavity <NUM> after the stirring disc <NUM> is immersed in the molten metal, in which case since the floating feedstock is located beneath the first opening <NUM>, it does not easily escape from the stirring disc <NUM> via the feedstock inlet <NUM>.

Referring to <FIG>, based on the example embodiments described supra, in one implementation of the disclosure, the feedstock holding portion <NUM> further comprises a baffle plate <NUM>, the baffle plate <NUM> being formed as extending from the cavity <NUM> between the feedstock inlet <NUM> and the first opening <NUM> towards the bottom wall of the cavity <NUM>, both sides of the baffle plate <NUM> being connected to the sidewalls of the cavity <NUM>. In a case that the density of the feedstock is lower than that of the molten metal, the feedstock will move upward after the stirring disc <NUM> is immersed in the molten metal; the baffle plate <NUM> serves to baffle the upward floating feedstock and limit the feedstock from moving towards the feedstock inlet <NUM>. The feedstock before floating upward is located in the cavity <NUM> offset from the feedstock inlet <NUM>; since the surface of the molten metal flows gently, the feedstock's upward floating follows a substantially vertically linear path, such that it does not easily move towards the direction of the feedstock inlet <NUM> during the upward floating process; even if the upward floating feedstock has a tendency of moving towards the feedstock inlet <NUM>, it will be baffled and stopped by the lower end of the baffle plate <NUM> after floating upward a certain height, thereby avoiding the circumstance that the feedstock is separated from the stirring disc <NUM> during the process of immersing the stirring disc <NUM> in the molten metal. In addition, since both sides of the baffle plate <NUM> are connected to the sidewalls of the cavity <NUM>, the feedstock cannot bypass the baffle plate <NUM> to move towards the feedstock inlet <NUM>.

Referring to <FIG>, as a further technical solution, the baffle plate <NUM> tilts from top to bottom towards the direction of the feedstock inlet <NUM>; the tilting design of the baffle plate <NUM> improves the feedstock baffling range of the lower end of the baffle plate <NUM>, which may enhance the feedstock baffling performance of the lower end of the baffle plate <NUM> and thus may improve reliability.

Supposing that the minimal interval between the lower end of the baffle plate <NUM> and the bottom wall of the cavity <NUM> is L, the diameter of the feedstock is R, L<<NUM>. 2R; with this design, the feedstock may be baffled by the baffle plate <NUM> after moving upward a small distance.

Referring to <FIG>, based on the embodiments described supra, in one implementation of the disclosure, the drive device <NUM> comprises a lifting power element <NUM> and a rotating power element <NUM>, a splined sleeve <NUM> fitting with the stirring rod <NUM> being sleeved over the stirring rod <NUM>, the rotating power element <NUM> being configured to drive the splined sleeve <NUM> to rotate. Due to the splined-fit between the stirring rod <NUM> and the splined sleeve <NUM>, the splined sleeve <NUM> does not limit up-and-down movement of the stirring rod <NUM> relative to the splined sleeve <NUM>. The lifting power element <NUM> is configurable to generate a power driving the stirring rod <NUM> to move up and down, allowing for the stirring disc <NUM> to be immersed in or lifted out of the molten metal or allowing for the stirring disc <NUM> to move up and down in the molten metal; the rotating power element <NUM> is configurable to drive the splined sleeve <NUM> to rotate, such that the splined sleeve <NUM> drives the stirring disc <NUM> to rotate in the molten metal, enhancing feedstock homogeneity in the molten metal.

Referring to <FIG>, based on the embodiments described supra, in one implementation of the disclosure, the stirring disc <NUM> comprises a plurality of feedstock holding portions <NUM>, and corresponding to the plurality of feedstock holding portions <NUM>, a plurality of feedstock inlets <NUM> are provided on the stirring disc <NUM>, the plurality of feedstock inlets <NUM> being arranged at intervals along the circumference of the stirring disc <NUM>. Provision of the plurality of feedstock holding portions <NUM> allows for more feedstock to be carried by the stirring disc <NUM>, which eliminates a need of frequent replenishment of feedstock. By arranging the feedstock holding portions <NUM> at intervals along the circumference of the stirring disc <NUM>, feedstock can be replenished to different parts of the molten metal, such that the feedstock is homogeneously melted in the molten metal without incurring intensive fluctuation or flow of the molten metal.

Referring to <FIG>, based on the embodiments described supra, in one implementation of the disclosure, the stirring disc <NUM> comprises a disc body <NUM> connected to the stirring rod <NUM> and an annular boss <NUM> disposed at the bottom of the disc body <NUM>, the height of the upper surface of the disc body <NUM> being gradually reduced from the stirring rod <NUM> to the periphery. The upper surface of the disc body <NUM> serves to guide the molten metal such that when the stirring disc <NUM> moves upward, the molten metal above the stirring disc <NUM> may be guided by the upper surface of the disc body <NUM> to flow towards the periphery of the disc body <NUM>, which can reduce the magnitude of stirring the molten metal, and during the process of the stirring disc <NUM> exiting the molten metal, the molten metal left on the upper surface of the stirring disc <NUM> may be reduced so as to prevent the cooled molten metal from blocking the openings.

A drainage port <NUM> through the lower surface of the stirring disc <NUM> is provided at the intersection between the bottom wall of the cavity <NUM> and the sidewall of the cavity <NUM> proximal to the second opening <NUM>. During the process of the stirring disc <NUM> exiting the molten metal, a part of the molten metal in the cavity <NUM> may be drained via the second opening <NUM> at the bottom wall of the cavity <NUM>, and the remaining part of the molten metal flows from the bottom wall of the cavity <NUM> towards the sidewall of the cavity <NUM>, converges there, and is drained via the drainage port <NUM>; this may reduce the amount of molten metal left on the stirring disc <NUM>.

An outer-ring wall <NUM> of the annular boss <NUM> is connected to the periphery of the disc body <NUM>. The openings further comprise a third opening <NUM>, the third opening <NUM> being located at a position on the disc body <NUM> corresponding to a circular space <NUM> enclosed by the annular boss <NUM>, the bottom end of the annular boss <NUM> being connected to its outer-ring wall <NUM> via a conical surface, the bottom end of the annular boss <NUM> being connected to the top wall of the circular space <NUM> also via the conical surface, such that the lower end of the annular boss <NUM> is shrunk from top to bottom, while the circular space <NUM> is gradually flared from top to bottom.

The annular boss <NUM> protrudes from the bottom of the disc body <NUM>, such that during the process of immersing the stirring disc <NUM> in the molten metal, the annular boss <NUM> first accesses the molten metal prior to the disc body <NUM>; since the lower end of the annular boss <NUM> is tapered, the annular boss <NUM>, during the process of being immersed in the molten metal, generates a reduced intensity in stirring the molten metal, without incurring an intensive fluctuation in the molten metal. The outer-ring wall <NUM> of the annular boss <NUM> is connected to the periphery of the disc body <NUM>, such that the periphery of the disc body <NUM> does not protrude from the annular boss <NUM>, which reduces the molten metal stirring magnitude at its peripheral portion during the process of immersing the disc body <NUM> in the molten metal, avoiding formation of a vortex around the stirring disc <NUM>. When the annular boss <NUM> is completely immersed into the molten metal, the top wall of the circular space <NUM> will be exposed to the molten metal; provision of the third opening <NUM> allows for the molten metal to pass through the third opening <NUM>, further reducing the molten metal stirring magnitude of the stirring disc <NUM>. In addition, provision of the circular space <NUM> can also reduce the overall weight of the stirring disc <NUM>, thereby reducing the load of the drive device <NUM>. The sidewall of the circular space <NUM> serves to guide the molten metal, which can reduce the molten metal stirring magnitude of the top wall of the circular space <NUM>.

A radial opening <NUM> communicating with the cavity <NUM> is further provided on the inner-ring wall <NUM> and the outer-ring wall <NUM> of the annular boss <NUM> so as to facilitate circulation of the molten metal in the cavity <NUM>.

Referring to <FIG>, based on the example embodiments described supra, in one implementation of the disclosure, a plurality of third openings <NUM> are provided on the top wall of the circular space <NUM>, the plurality of third openings <NUM> being disposed at intervals along the circumference of the stirring rod <NUM>, the plurality of third openings <NUM> being arranged into a plurality of groups along concentric circles, as illustrated in <FIG> illustrates two groups of third openings disposed on the stirring disc <NUM>, one group thereof including three third openings <NUM>, the other group thereof including six third openings <NUM>. Among the plurality of groups of third openings, the portion of the top wall of the circular space <NUM> around the first group of third openings is higher than remaining portions of the top wall of the circular space <NUM> (as illustrated in <FIG>, the group of the two groups of third openings closer to the stirring rod are located at the highest position), such that during the process of immersing the stirring disc <NUM> into the molten metal, the gas in the circular space <NUM> is discharged via that group of third openings.

Referring to <FIG>, based on the example embodiments described supra, in one implementation thereof, the metal melting furnace further comprises an automatic charger <NUM> configured to replenish feedstock to the feedstock holding portion <NUM>, the rotating power element <NUM> driving the stirring disc <NUM> to rotate intermittently to replenish the feedstock to each feedstock holding portion <NUM>. The automatic charger <NUM> allows for automatic replenishment of the feedstock to the stirring disc <NUM>, which eliminates manual charging, thereby enhancing operation safety as well as operation efficiency. Since a plurality of feedstock holding portions <NUM> are arranged on the stirring disc <NUM>, during the feedstock replenishing process, the rotating power element <NUM> drives the stirring disc <NUM> to rotate to switch the feedstock holding portion <NUM> to be aligned to the automatic charger <NUM>, whereby the feedstock is replenished to each feedstock holding portion <NUM> piece by piece. During the charging process, the stirring disc <NUM> rotates intermittently, such that during the process of the feedstock falling into the cavity <NUM>, the stirring disc <NUM> and the automatic charger <NUM> are relatively still, avoiding offset when the feedstock drops off.

In one implementation, the automatic charger <NUM> comprises an outlet path <NUM>, a feedstock reservoir <NUM> communicating with the outlet path <NUM>, and a pusher <NUM>, the pusher <NUM> being configured to push the feedstock in the outlet path <NUM> such that the feedstock falls onto the feedstock holding portion <NUM>. The feedstock reservoir <NUM> communicates with the outlet path <NUM>, such that the feedstock in the feedstock reservoir <NUM> can access the outlet path <NUM>; the pusher <NUM> may push the feedstock in the outlet path <NUM> such that the feedstock is pushed out of the outlet path <NUM> and enters the cavity <NUM> via the feedstock inlet <NUM>, thereby realizing automatic replenishment of the feedstock.

In the implementation above, the outlet path <NUM> comprises a rising segment <NUM> and a descending segment <NUM>, bottom walls of the rising segment <NUM> and the descending segment <NUM> being both inclined surfaces; in the direction from the rising segment <NUM> to the descending segment <NUM>, the bottom wall of the rising segment <NUM> is an upward inclined surface, such that the feedstock may be kept in the rising segment <NUM> without autonomously entering the descending segment <NUM>; the bottom wall of the descending segment <NUM> towards the direction away from the rising segment <NUM> is a descending inclined surface, such that after the pusher <NUM> pushes the feedstock from the rising segment <NUM> to the descending segment <NUM>, the feedstock may roll out of the outlet path <NUM> along the bottom wall of the descending segment <NUM> under its own gravity.

A plurality of pieces of feedstock may be stored in the rising segment <NUM>; during return movement of the pusher <NUM>, the feedstock in the rising segment <NUM> also has a tendency of moving backward, which would affect replenishment of the feedstock from the feedstock reservoir <NUM> into the outlet path <NUM>. To solve this problem, in one implementation of the disclosure, the pusher <NUM> comprises a base <NUM>, two pushing arms <NUM> rotatably mounted on the base <NUM>, and a pushing ram <NUM> configured to push the base <NUM>. The automatic charger <NUM> further comprises a slide groove <NUM> communicating with the outlet path <NUM> for the pusher <NUM> to enter/exit the outlet path <NUM>. The two pushing arms <NUM> are folded when pushing the feedstock, and the two folded pushing arms <NUM> can also enclose an avoidance hole <NUM>. The feedstock reservoir <NUM> is disposed above the outlet path <NUM> and communicates with the outlet path <NUM> via a vertical feed path <NUM>. The feedstock in the feedstock reservoir <NUM> enters the outlet path <NUM> via the avoidance hole <NUM>. During return movement of the pusher <NUM>, the two pushing arms <NUM> are deployed so as to be separated from the feedstock in the avoidance hole <NUM>. The pushing ram <NUM> may push the base <NUM> to drive the pushing arms <NUM> to move; the pushing arms <NUM> may extend out of the slide groove <NUM> along with the base <NUM> to access the outlet path <NUM>; during the pushing process, the pushing arms <NUM> are kept folded so as to push the feedstock in the outlet path <NUM> such that the feedstock moves forward and falls onto the feedstock holding portion <NUM> from the outlet path <NUM>; since the two folded pushing arms <NUM> can enclose the avoidance hole <NUM>, the feedstock in the feed path <NUM> can fall off and pass through the avoidance hole <NUM> during the process of the pushing arms <NUM> pushing the feedstock and then enters the outlet path <NUM>, whereby replenishment of the feedstock into the outlet path <NUM> is completed; during return movement of the pusher <NUM>, the two pushing arms <NUM> are deployed to be separated from the feedstock, such that the pushing arms <NUM> may be retracted into the slide groove <NUM>.

A protrusion portion <NUM> is provided at a portion of the rising segment <NUM> connected to the descending segment <NUM>; the protrusion portion <NUM> is configured to block the feedstock. The feedstock, when being pushed, may cross the protrusion portion <NUM> to enter the descending segment <NUM>; therefore, the protrusion portion <NUM> may avoid the feedstock from autonomously entering the descending segment <NUM>. The upper surface of the protrusion portion <NUM> is a convex arc surface.

Referring to <FIG>, based on the example embodiments described supra, in one implementation of the disclosure, to push the feedstock, an end portion of the pushing ram <NUM> extends out of the base <NUM> till between the two pushing arms <NUM> to stop rotation of the pushing arms <NUM>; upon return movement, the end portion of the pushing ram <NUM> is retracted into the base <NUM>; after the feedstock pushes the two pushing arms <NUM> to be deployed, the pusher <NUM> is separated from the feedstock. An avoidance groove <NUM> for avoiding the pushing arms <NUM> is provided at a sidewall of the outlet path <NUM>, and a guide groove <NUM> connected to the avoidance groove <NUM> is provided at a sidewall of the slide groove <NUM>. In the return movement direction of the pusher <NUM>, the guide groove <NUM> is shrunk to push the two pushing arms <NUM> to be folded. The end portion of the pushing ram <NUM> may extend out of the base <NUM> during the pushing process. The end portion of the pushing ram <NUM> is disposed between the two pushing arms <NUM> so as to be capable of stopping the two pushing arms <NUM>, whereby rotation of the two pushing arms <NUM> is limited such that the two pushing arms <NUM> can be kept in a folded state so as to push the feedstock to move. Upon return movement, since the end portion of the pushing ram <NUM> has been retracted in the base, rotation of the two pushing arms <NUM> is not limited. Since the size of the feedstock is greater than that of the slide groove <NUM>, the feedstock cannot access the slide groove <NUM>; therefore, during return movement of the pusher <NUM>, a mutually compressive force occurs between the pushing arms <NUM> and the feedstock, where the compressive force causes the two pushing arms <NUM> to be separated and deployed, thereby being separated from the feedstock. The avoidance groove <NUM> may provide a space for deployment of the pushing arms <NUM>. The guide groove <NUM> is connected to the avoidance groove <NUM>, such that the deployed pushing arms <NUM> may enter the guide groove <NUM> from the avoidance groove <NUM>. As the base <NUM> moves, the pushing arms <NUM> will contact the inner wall of the guide groove <NUM> and be gradually pushed by the inner wall of the guide groove <NUM>, such that the two pushing arms <NUM> move close to each other to be refolded.

A limiting groove <NUM> is provided in the base <NUM>, and a limiting protrusion <NUM> is provided on the pushing ram <NUM>. The limiting protrusion <NUM> may abut against the inner wall of the limiting groove <NUM> so as to keep the pushing ram <NUM> on the base <NUM>. The pushing ram <NUM> is extensible relative to the base <NUM>; after the pushing ram <NUM> is retracted, the limiting protrusion <NUM> abuts against the inner wall of the limiting groove <NUM> such that the pushing ram <NUM> can bring the base <NUM> to move together.

Referring to <FIG>, based on the example embodiments described supra, in one implementation of the disclosure, the metal melting furnace including a stirring device further comprises a rotating chassis <NUM> rotatably mounted on the furnace body <NUM>, the stirring device being provided on the rotating chassis <NUM>, the automatic charger <NUM> being disposed at a side portion of the furnace body <NUM>, the rotating chassis <NUM> bringing the stirring disc <NUM> to rotate till beneath the automatic charger <NUM> so as to replenish the feedstock. As the rotating chassis <NUM> rotates, it can bring the stirring disc <NUM> to rotate together, such that the stirring disc <NUM> can be aligned to the automatic charger <NUM> for automatic charging; after the stirring disc <NUM> completes feedstock replenishment to the molten metal, the rotating chassis <NUM> may also move the stirring disc <NUM> out of the furnace body <NUM> for being cooled, avoiding a circumstance that the stirring disc <NUM> is kept at a high temperature due to the high-temperature molten metal such that the feedstock is oxidized under the high temperature during loading process of the stirring disc <NUM>.

As illustrated in <FIG>, different from the example embodiments described supra, in another implementation of the disclosure, there is further provided another type of stirring device and an automatic charging device capable of replenishing feedstock to the feedstock holding portion <NUM>, the automatic charging device comprising an inlet path <NUM> provided in the stirring rod <NUM> along an axial line of the stirring rod <NUM> and a feedstock replenishing port <NUM> communicating with the inlet path <NUM>, the cavity <NUM> of the feedstock holding portion <NUM> communicating with the inlet path <NUM>. Upon feedstock replenishment, the feedstock is loaded to the inlet path <NUM> via the feedstock replenishing port <NUM> such that the feedstock falls off along the inlet path <NUM> to be thereby replenished into the cavity <NUM>. The bottom wall of the inlet path <NUM> has a convex arc shape, which may guide the feedstock to move towards the feedstock holding portion <NUM>.

In one implementation of the disclosure, the feedstock inlet <NUM> is disposed at a side of the cavity <NUM> proximal to the stirring rod <NUM>, the feedstock inlet <NUM> communicating with the inlet path <NUM>, the cavity <NUM> being of a ring shape, the baffle plate <NUM> on the top wall of the cavity <NUM> being provided as an annular protrusion rib. During the charging process, the stirring rod <NUM> may rotate such that the feedstock entering the cavity <NUM> rolls in the cavity <NUM>, which results in homogeneous distribution of the feedstock and meanwhile avoids the feedstock from blocking the feedstock inlet <NUM> causing the feedstock accumulated in the inlet path <NUM>. The bottom wall of the cavity <NUM> tilts outward gradually downward from the stirring rod <NUM>, which avoids accumulation of the feedstock around the feedstock inlet <NUM>. A feedstock guide chute <NUM> connected to the feedstock replenishing port <NUM> is provided at the outer side of the stirring rod <NUM>, such that an external feedstock storage device may transfer the feedstock to the feedstock guide chute <NUM>, and then the feedstock guide chute <NUM> guides the feedstock into the inlet path <NUM>.

<FIG> illustrates another type of automatic charger <NUM> according to some embodiments of the disclosure, the automatic charger <NUM> comprising a hopper <NUM>, a buffer bin <NUM>, and a pushing mechanism <NUM>, the hopper <NUM> being provided with a inlet opening <NUM> and an outlet opening <NUM>, a buffer channel <NUM> being provided in the buffer bin <NUM>, one end of the buffer channel <NUM> being provided with a feed port <NUM> communicating with the outlet opening <NUM>, the other end of the buffer channel <NUM> being in communication with the feedstock inlet <NUM> of the feedstock holding portion <NUM>; the pushing mechanism <NUM> is configured to push the feedstock in the buffer channel <NUM> sequentially into the feedstock inlet <NUM> of the feedstock holding portion <NUM>, the pushing mechanism <NUM> comprising a drive <NUM> and a pushing element <NUM>, the drive <NUM> driving the pushing element <NUM> to perform a reciprocating movement in the buffer channel <NUM> to sequentially push the feedstock in the buffer channel <NUM> into the feedstock inlet <NUM>.

In the technical solution above, the feedstock may be first inputted into the hopper <NUM> via the inlet opening <NUM>, which may be done manually or automatically by a mechanical device. The feedstock in the hopper <NUM> sequentially enters the buffer channel <NUM> via the outlet opening <NUM>, and then the pushing mechanism <NUM> sequentially pushes the feedstock in the buffer channel <NUM> into the feedstock inlet <NUM>. Each reciprocating movement of the pusher <NUM> allows for a certain amount of feedstock to be pushed into the feedstock inlet <NUM>; therefore, by controlling the number of reciprocating times of the pushing element <NUM>, the quantity of feedstock to be charged can be accurately controlled. Since the mass of each piece of feedstock is substantially consistent, accurate control of the feedstock charging amount may be realized via this technical solution. The drive <NUM> is fixed to the outer sidewall of the buffer bin <NUM>, and the pushing element <NUM> and the buffer bin <NUM> are slidingly connected.

A plurality of storage channels <NUM> are further inclinedly provided in the buffer bin <NUM>, the plurality of storage channels <NUM> being sequentially arranged in the vertical direction, where in two neighboring storage channels <NUM>, the lower end of the upper storage channel <NUM> communicates with the upper end of the lower storage channel <NUM>, the lowest storage channel <NUM> is disposed above the buffer channel <NUM>, the upper end of the uppermost storage channel <NUM> communicates with the outlet opening <NUM>, and the lower end of the storage channel <NUM> communicates with the buffer channel <NUM>. The storage channels <NUM> are configurable to store a part of feedstock, thereby increasing the quantity of pre-stored feedstock.

A plurality of through bores <NUM> are provided on both of the inner wall of the buffer channel <NUM> and the inner wall of the storage channel <NUM> such that high-temperature gas in the furnace body <NUM> can access the buffer bin <NUM> and then enter the buffer channel <NUM> and the storage channel <NUM> via the through bores <NUM> so as to preheat the feedstock in the buffer bin <NUM>; in this way, the heat of the high-temperature gas discharged from the inside of the furnace body <NUM> may be sufficiently recycled to save energy; in addition, preheating the feedstock may reduce the melting time in the chamber <NUM>, thereby enhancing efficiency. The buffer bin <NUM> is provided with a gas outlet for discharging the high-temperature gas.

As illustrated in <FIG>, based on the example embodiments described supra, in one implementation thereof, the pushing element <NUM> is disposed beneath the feed port <NUM>. The buffer channel <NUM> comprises a forward tilting segment <NUM> and a backward tilting segment <NUM>, the forward tilting segment <NUM> being disposed at the side proximal to the pushing mechanism <NUM>, the backward tilting segment <NUM> being disposed at the side proximal to the feedstock inlet <NUM>, the bottom surface of the forward tilting segment <NUM> being disposed to tilt from top to bottom towards the direction of the feedstock holding portion <NUM>, the bottom surface of the backward tilting segment <NUM> being disposed to tilt from bottom to top towards the direction of the feedstock holding portion <NUM>.

Tilting arrangement of the bottom surface of the forward tilting segment <NUM> from top to bottom towards the direction of the feedstock holding portion <NUM> allows for the feedstock in the forward tilting segment <NUM> to move towards the side of the feedstock holding portion <NUM>; as the pushing element <NUM> is being retracted, this tilting arrangement may prevent the feedstock from moving back with the pushing element <NUM>, such that the feedstock in the storage channel <NUM> may smoothly fall into the buffer channel <NUM>. Tilting arrangement of the bottom surface of the backward tilting segment <NUM> from bottom to top towards the direction of the feedstock holding portion <NUM> may prevent the feedstock not pushed into the feedstock holding portion <NUM> in the backward tilting segment <NUM> from being pushed out of the buffer channel <NUM> due to inertance when the pushing element <NUM> extends out.

The forward tilting segment <NUM> and the backward tilting segment <NUM> may be directly connected or connected via a horizontally disposed horizontal segment.

As illustrated in <FIG> and <FIG>, based on the example embodiments described supra, in one implementation of the disclosure, a height of the upper end surface of the pushing element <NUM> relative to the bottom surface of the buffer channel <NUM> is h1 , a height of the feedstock in the buffer channel <NUM> relative to the bottom surface of the buffer channel <NUM> is h2, and h2≥h1, such that when the pushing element <NUM> extends out, at least a part of the feedstock above the buffer channel <NUM> enters the buffer channel <NUM> and accesses the upper end surface of the pushing element <NUM>.

When the pushing element <NUM> extends out, the feedstock below the feed port <NUM> will be pushed forward, while when the pushing element <NUM> is being retracted, the feedstock rolls back till under or below the feed port <NUM> along with the pushing element <NUM>, and the rolling-back feedstock will block the feedstock above the feed port <NUM> from falling off into the buffer channel <NUM> and be stuck at the feed port <NUM>; as a result, the feedstock in the buffer channel <NUM> fails to be replenished, and thereafter, when the pushing element <NUM> extends out again, since the buffer channel <NUM> has no new feedstock replenished, there will be no feedstock to be pushed from the buffer channel <NUM> into the feedstock holding portion <NUM>, such that the automatic charger <NUM> cannot charge the feedstock smoothly. In this implementation, when the pushing element <NUM> extends out, the feedstock in the buffer channel <NUM> may be pushed into the feedstock inlet <NUM>; meanwhile, the feedstock above the pushing element <NUM> will enter the buffer channel <NUM> via the feed port <NUM> and access the upper end surface of the pushing element <NUM>, and then when the pushing element <NUM> is being retracted, the feedstock having fallen on the pushing element <NUM> may block the feedstock in the buffer channel <NUM> from moving backward; after the pushing element <NUM> is retracted, the feedstock on the pushing element <NUM> may continuously move downward under the gravity and access the bottom surface of the buffer channel <NUM>, thereby completing the feeding.

In some implementations of the disclosure, h2≥2h1. This solution enables the feedstock above the pushing element <NUM> to fall into the buffer channel <NUM> as much as possible when the pushing element <NUM> extends out, thereby increasing the baffling effect of the feedstock above the pushing element <NUM> with respect to the feedstock in the buffer channel <NUM>, such that the feedstock above the feed port <NUM> enters the buffer channel <NUM> more smoothly; in order to prevent the feedstock in the buffer channel <NUM> from rolling into the feedstock holding portion <NUM> before the pushing element <NUM> pushes the feedstock, the bottom surface of the buffer channel <NUM> tilts from bottom to top towards the direction of the feedstock holding portion <NUM>.

As illustrated in <FIG> and <FIG>, based on the example embodiments described supra, in another implementation of the disclosure, the pushing mechanism <NUM> comprises a first drive <NUM>, a second drive <NUM>, a first pushing element <NUM>, and a second pushing element <NUM>, the first drive <NUM> driving the first pushing element <NUM> to perform a reciprocating movement in the buffer channel <NUM>, the second drive <NUM> driving the second pushing element <NUM> to perform a reciprocating movement in the buffer channel <NUM>, the first pushing element <NUM> and the second pushing element <NUM> being disposed in juxtaposition below the feed port <NUM>, a height of the second pushing element <NUM> being lower than that of the first pushing element <NUM>, where supposing that the height of the upper end surface of the second pushing element <NUM> relative to the bottom surface of the buffer channel <NUM> is h3, the height of the feedstock in the buffer channel <NUM> relative to the bottom surface of the buffer channel <NUM> is h2, 3h3≤h2≤4h3; when pushing the feedstock, the first pushing element <NUM> and the second pushing element <NUM> simultaneously extend out; after the feedstock in the buffer channel <NUM> is completely pushed, the first pushing element <NUM> is retracted first, such that the feedstock above the buffer channel <NUM> at least partially enters the buffer channel <NUM> to access the upper end face of the second pushing element <NUM>.

In order to prevent occurrence of a circumstance that the rolling-back feedstock blocks falling of the feedstock above the feed port <NUM> such that the feedstock above the feed port <NUM> cannot fall into the buffer channel <NUM> and is stuck at the feed port <NUM>, in this implementation, in a case of a need to charge feedstock, the first pushing element <NUM> and the second pushing element <NUM> extend out simultaneously, which may push the foremost feedstock in the buffer channel <NUM> into the feedstock inlet <NUM>, and then the first pushing element <NUM> is retracted while the second pushing element <NUM> maintains stationary; this may prevent rolling-back of the feedstock in the buffer channel <NUM> while allowing for the feedstock above the buffer channel <NUM> to at least partially enter the buffer channel <NUM> to access the upper end face of the second pushing element <NUM>; now, the part of feedstock having fallen into the buffer channel <NUM> may block rolling-back of the feedstock previously disposed in the buffer channel <NUM>; then, the second pushing element <NUM> is retracted; since a part of the feedstock on the second pushing element <NUM> has been located in the buffer channel <NUM>, it is not easily stuck by the feedstock in the buffer channel <NUM>; therefore, the feedstock on the second pushing element <NUM> may continuously move downward under the gravity to access the bottom surface of the buffer channel <NUM>, thereby completing the loading.

Simultaneous extension of the first pushing element <NUM> and the second pushing element <NUM> may ensure that the feedstock in the buffer channel <NUM> is pushed into the feedstock inlet <NUM>, while after the first pushing element <NUM> and the second pushing element <NUM> extend out, it is only needed to limit the feedstock in the buffer channel <NUM> to prevent its backward-rolling, without a need to provide a power for pushing the feedstock. Therefore, the second pushing element <NUM> may be disposed lower in height. In some implementations, h3 ≤ h2/<NUM>, namely 3h3 ≤h2. Lower height of the second pushing element <NUM> allows for enough feedstock above the buffer channel <NUM> to fall into the buffer channel <NUM> after the first pushing element <NUM> is retracted, which can block the feedstock falling into the buffer channel <NUM> from rolling back, and ensures the remaining feedstock to completely fall into the buffer channel <NUM> after the second pushing element <NUM> is retracted. If the second pushing element <NUM> is arranged too low, the feedstock in the buffer channel <NUM> might roll till above the pushing element <NUM>, unable to block backward-rolling of the feedstock; therefore, in order to guarantee the blocking effect, it is needed to provide a certain height for the second pushing element <NUM>, e.g., h2/<NUM>≤h3, i.e., h2≤4h3.

<FIG> illustrate another type of metal melting furnace including a stirring device, comprising a furnace body <NUM> and a stirring device, the furnace body <NUM> defining a chamber <NUM> configured to accommodate molten metal, the stirring device comprising a stirring rod <NUM> and a drive device, a feedstock holding portion <NUM> and an impeller <NUM> being provided on the stirring rod <NUM>, the drive device being in drive connection with the stirring rod <NUM> to drive the stirring rod <NUM> to rotate and lift, such that the feedstock holding portion <NUM> and the impeller <NUM> immersed in the molten metal rotate to stir the molten metal; during the stirring process, the feedstock is held onto the feedstock holding portion <NUM> such that the feedstock moves along with the feedstock holding portion <NUM> so as to be melted in the molten metal.

The principle of the drive device in driving the stirring rod to lift and rotate is identical to those described in the implementations noted supra.

During the smelting process, the feedstock charged in the molten metal may be held on the feedstock holding portion <NUM>, such that the feedstock may be immersed into the molten metal along with the feedstock holding portion <NUM> without floating on top of the molten metal, which prevents the feedstock from being exposed to the air in the high-temperature environment and oxidized to cause abnormal loss of the feedstock; in addition, the oxygen content in the molten metal may also increase; the feedstock does not flow on top of the molten metal or sink to the bottom of the molten metal, without not causing inhomogeneous distribution of the composition of the molten metal. Driven by the drive device, the stirring rod <NUM> may drive the impeller <NUM> and the feedstock holding portion <NUM> to rotate to stir the molten metal, which may improve homogeneity of the feedstock in the molten metal to ensure consistent quality of the metal products; in addition, it eliminates a need for manual stirring, which reduces labor intensity of operators and lowers risks. Moreover, the automatic stirring offers a larger stirring range than manual stirring, preventing quality defects due to insufficient stirring of some areas in the molten metal; in addition, its stirring efficiency is also higher than the manual operation with reduced stirring duration.

In one implementation, the feedstock holding portion <NUM> comprises a housing <NUM>, a cavity <NUM> defined by the housing <NUM>, and a through hole <NUM> which is provided on the housing <NUM> and communicates with the cavity <NUM>, the through hole <NUM> having a size smaller than that of the feedstock. The feedstock is accommodated in the cavity <NUM>; during the stirring process, the molten metal may access the cavity <NUM> via the through hole <NUM> so as be sufficiently mixed with the feedstock; then, the molten metal mixed with the feedstock composition flows out of the cavity <NUM> via the through hole <NUM> so as to be mixed with the external molten metal; in this way, the feedstock is homogeneously distributed in the molten metal. Since the size of the through hole <NUM> is smaller than that of the feedstock, the feedstock can be kept in the cavity <NUM>. As the feedstock is melted, its size will be shrunk to be smaller than that of the through hole <NUM>, such that the feedstock likely exits the feedstock holding portion <NUM> via the through hole <NUM>; however, since the feedstock size has been significantly shrunk, even if it floats on top of the molten metal or sinks to the bottom of the molten metal, there would have little impact on the composition of the molten metal; and if the molten metal has a high melting point, the feedstock would be completely melted before floating on top of the molten metal or sinking to bottom of the molten metal.

A plurality of feedstock holding portions <NUM> and a plurality of impellers <NUM> are arranged at intervals along a circumferential direction of the stirring rod <NUM>. The plurality of feedstock holding portions <NUM> allow for more feedstock to be charged into the molten metal at one time, and the plurality of impellers <NUM> allow for enhancing molten metal stirring efficiency and improving homogeneity of feedstock distribution in the molten metal.

The cavity <NUM> comprises an inlet zone <NUM> and a melting zone <NUM>, an inlet hole <NUM> commutating with the cavity <NUM> to feed feedstock to the inlet zone <NUM> being further provided on the housing <NUM>, a feedstock guide portion for guiding the feedstock from the inlet zone <NUM> to the melting zone <NUM> being provided at a bottom wall of the cavity <NUM>, the feedstock guide portion being of a bevel structure. The feedstock inlet <NUM> communicates with the cavity <NUM> so as to replenish the feedstock to the feedstock holding portion <NUM> after the feedstock is used up, the feedstock entering the inlet zone <NUM> via the feedstock inlet <NUM>; the feedstock charged in the cavity <NUM> via the feedstock inlet <NUM> may move to the melting zone <NUM> from the inlet zone <NUM> along the feedstock guide portion under its own gravity, thereby reducing the odds of the feedstock exiting the feedstock holding portion <NUM> via the feedstock inlet <NUM>.

In a rotating direction of the stirring rod <NUM> (in <FIG>, the arrow in the stirring rod <NUM> denotes the rotating direction of the stirring rod <NUM>), the front end of the impeller <NUM> is higher than the rear end so as to guide the molten metal to flow from top to bottom during the rotating process; in this way, the molten metal in the bottom layer will not be brought to move upward, without causing diffusion of the impurities in the bottom layer of the molten metal and deteriorating product quality. The stirring rod <NUM> can bring the impeller <NUM> to rotate slowly, such that the molten metal flows gently without causing upward surge of the bottom-layer molten metal.

In some implementations, the feedstock holding portion <NUM> is disposed above the impeller <NUM>, which can facilitate replenishment of the feedstock to the feedstock holding portion <NUM>; the molten feedstock is distributed in the top-layer molten metal, such that during the process of stirring the molten metal, the impeller <NUM> can guide the top-layer molten metal including extensive feedstock composition to move downward, thereby homogenizing feedstock distribution.

Of course, the feedstock holding portion may also be disposed below the impeller, such that under the action of the impeller, the flow rate of the molten metal passing through the feedstock holding portion may increase, which facilitates diffusion of the feedstock.

Alternatively, the feedstock holding portion may be disposed between two layers of impellers, where the upper-layer impeller may increase the flow rate of the molten metal passing through the feedstock holding portion, and the lower-layer impeller allows for the molten metal including feedstock composition to flow and diffuse downward.

Claim 1:
A metal melting furnace including a stirring device, comprising:
a furnace body (<NUM>) defining a chamber (<NUM>) for accommodating molten metal;
the stirring device comprising a stirring disc (<NUM>) and a drive device (<NUM>), the stirring disc (<NUM>) comprising a disc body (<NUM>), a feedstock holding portion (<NUM>), and a feedstock inlet (<NUM>) via which feedstock is replenished to the feedstock holding portion (<NUM>), a stirring rod (<NUM>) being connected on the disc body (<NUM>), a plurality of vertically through openings being provided on the disc body (<NUM>) and/or on the feedstock holding portion (<NUM>), the drive device (<NUM>) being in drive connection to the stirring rod (<NUM>), the drive device (<NUM>) being configured to drive the stirring rod (<NUM>) to lift such that the stirring disc (<NUM>) is immersed in or lifted out of the molten metal in the chamber (<NUM>), the feedstock holding portion (<NUM>) being configured to hold the feedstock on the stirring disc (<NUM>) such that the feedstock moves together with the stirring disc (<NUM>),
wherein the feedstock holding portion (<NUM>) comprises a cavity (<NUM>) configured to accommodate the feedstock, the feedstock inlet (<NUM>) communicating with the cavity (<NUM>), the openings comprising a first opening (<NUM>) provided at a top wall of the cavity (<NUM>) and a second opening (<NUM>) provided at a bottom wall of the cavity (<NUM>), the first opening (<NUM>) and the second opening (<NUM>) having a size smaller than a size of the feedstock to hold the feedstock on the stirring disc (<NUM>) via the feedstock holding portion (<NUM>), and
wherein the stirring disc (<NUM>) further comprises an annular boss (<NUM>) disposed at a bottom portion of the disc body (<NUM>), an outer-ring wall (<NUM>) of the annular boss (<NUM>) being connected to a periphery of the disc body (<NUM>), a lower end of the annular boss (<NUM>) being tapered from top to bottom.