Conductive furnace bottom structure and submerged arc furnace

Abstract

The utility model relates to the technical field of smelting equipment, in particular to a conductive furnace bottom structure, which is formed by arranging a furnace bottom electrode for introducing direct current on a working layer and is matched with an adjustable direct current loop of the furnace bottom electrode, so that materials at the furnace bottom part can be heated, the materials are heated more uniformly, and the service life of the materials is prolonged. The problem that the furnace bottom is cooled due to unreasonable distribution of the hot layer at the furnace bottom is avoided; and meanwhile, the wire outlet end of the bottom furnace bottom electrode is arranged on the side face of the furnace bottom shell, that is, through a side face wire outlet mode, potential safety hazards can be effectively reduced while effective heat dissipation is achieved, and maintenance and use are convenient. Meanwhile, the utility model further provides the submerged arc furnace comprising the conductive furnace bottom structure.

Description

TECHNICAL FIELD

[0001] The utility model relates to smelting equipment technical field, concretely relates to a conductive furnace bottom structure and a submerged arc furnace. BACKGROUND

[0002] The submerged arc furnace directly utilizes electric energy to convert into heat energy, has higher energy conversion efficiency, is widely used in smelting of various metals and non-metallic minerals, and is divided into the power frequency AC power supply type and the direct current power supply type submerged arc furnace according to power supply mode.The submerged arc furnace of power frequency AC power supply mode is the most widely used one, especially occupies the dominant position in traditional industries such as ferroalloy and calcium carbide, and has simple equipment structure, low initial investment and controllable maintenance cost;but under the input of power frequency AC, electrode voltage drop is large, and it is difficult to input active power to the furnace bottom, that is, the heat layer distribution of AC furnace is unreasonable, and then the cold furnace bottom is formed.The submerged arc furnace of direct current power supply mode: in recent years, it has developed rapidly, four direct current electrodes are usually arranged in the furnace, there is no current zero point in direct current arc, and arc length and input power are more stable;compared with the AC power supply mode, there is no electrode voltage drop and material flow loss, and active power is beneficial to the delivery of furnace bottom;but compared with the AC three-electrode, the electrode spacing is small, there is no arc in the core of four-electrode direct current furnace, power distribution is unreasonable, and the current flowing through the furnace bottom is still small, and the heat layer cannot effectively reach the furnace bottom;at present, there are still some direct current submerged arc furnaces provided with bottom electrodes, but it is difficult to build the large-current bottom electrode, and usually the electrode is placed at the bottom, and the cooling device is prone to danger in the use process, once the furnace bottom is burnt through, there will be higher safety hazards.Therefore, based on the above problems, the furnace bottom structure needs to be further improved. SUMMARY

[0003] The utility model discloses a conductive furnace bottom structure to solve the prior art problems in the background art.

[0004] To solve the above technical problems, the utility model provides a technical scheme: a conductive furnace bottom structure is provided, which comprises a furnace bottom shell, a heat preservation layer, a working layer and a furnace bottom electrode, the heat preservation layer and the working layer are arranged inside the furnace bottom shell and are sequentially arranged from bottom to top, the furnace bottom electrode is arranged on the working layer and is provided in plurality, one end of the furnace bottom electrode is arranged on the working layer, the other end penetrates the outer lateral wall of the furnace bottom shell and is electrically connected with a power supply device, and the power supply device provides direct current for the furnace bottom electrode.

[0005] On the basis of the above technical scheme, the lateral wall of the furnace bottom shell is provided with a wire outlet, the connecting end of the furnace bottom electrode is arranged at the wire outlet, and the cooling device is arranged on the furnace bottom electrode and located outside the furnace shell.

[0006] On the basis of the above technical scheme, the power supply device comprises an off-oven busbar and an automatic current conversion device, one end of the off-oven busbar is connected with the oven bottom electrode, and the other end is connected with the automatic current conversion device, and the automatic current conversion device is connected with the power grid.

[0007] On the basis of the above technical scheme, the connecting end comprises a conductive plate and a fastener, the conductive plate is sleeved outside the oven bottom electrode, mounting holes are formed in the conductive plate, and the fastener is arranged in the mounting holes to press the off-oven busbar and the oven bottom electrode.

[0008] On the basis of the above technical scheme, the cooling device is a cooling water pipe, a cooling groove is formed in one end of the oven bottom electrode outside the oven body shell, a plurality of cooling water pipes are arranged in the cooling groove, and circulating cooling water is introduced into the cooling water pipes.

[0009] On the basis of the above technical scheme, the oven bottom electrode is uniformly provided with a plurality of electrodes along the circumference of the working layer.

[0010] On the basis of the above technical scheme, one end of the oven bottom electrode close to the center of the working layer is provided as an anode, and the anodes are arranged at an included angle.

[0011] On the basis of the above technical scheme, the working layer is made of high-thermal-resistance carbon bricks, the heat preservation layer is made of one of heat insulation fibers and light-weight clay bricks, and the oven bottom shell is made of steel plate.

[0012] On the other hand, the application also provides a submerged arc furnace comprising the conductive oven bottom structure, and further comprising an oven body, wherein the conductive oven bottom structure is arranged at the inner bottom end of the oven body, a plurality of top electrodes are arranged at the inner top end of the oven body, and alternating current is input into the top electrodes.

[0013] The technical scheme of the utility model has the advantages of:

[0014] The conductive oven bottom structure comprises an oven bottom electrode for inputting direct current into the working layer, and the adjustable direct current loop of the oven bottom electrode can heat the materials in the oven bottom part, so that the materials are heated more uniformly, and the problem of unreasonable distribution of the hot layer in the oven bottom part and the problem of cold oven bottom are avoided. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is the internal structure schematic view of the utility model;

[0016] Figure 2 is the structure principle schematic view of the utility model;

[0017] Figure 3 is the circuit control principle schematic diagram of the utility model;

[0018] Figure 4 is the overhead view of the furnace bottom electrode in the utility model in the furnace body;

[0019] Figure 5 is the structure schematic diagram of the connecting end of the furnace bottom electrode in the utility model; DETAILED DESCRIPTION

[0020] The utility model will be further described below in combination with the drawings and embodiments:

[0021] In the utility model, unless there are explicit provisions and limitations, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication between two elements or the interaction relationship between two elements. For ordinary skilled persons in the art, the specific meaning of the above-mentioned terms in the utility model can be understood according to the specific circumstances.

[0022] In the description of the utility model, it should be understood that the orientation or positional relationship indicated by the terms "left", "right", "front", "back", "top", "bottom" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model.

[0023] As shown in Figures 1 to 5 A conductive furnace bottom structure, comprising a furnace bottom shell 1, a heat preservation layer 2, a working layer 3 and a furnace bottom electrode 4, the heat preservation layer 2, the working layer 3 are arranged in the inside of the furnace bottom shell 1 and are sequentially arranged from bottom to top, the furnace bottom electrode 4 is arranged on the working layer 3 and is arranged in plurality, one end of the furnace bottom electrode 4 is arranged on the working layer 3, the other end penetrates the outside wall of the furnace bottom shell 1 and is electrically connected with a power supply device, the power supply device provides direct current for the furnace bottom electrode 4.

[0024] The utility model discloses a kind of conductive furnace bottom structure, by being provided with the furnace bottom electrode 4 of direct current in working layer 3 form conductive furnace bottom structure, cooperate the adjustable direct current loop of furnace bottom electrode 4, the heating of furnace bottom part material can be realized, material heating is more uniform, avoid the problem that hot layer is distributed unreasonably in furnace bottom part and then cold furnace bottom;While the outgoing line end of bottom furnace bottom electrode 4 is arranged in the side of furnace bottom shell 1, i.e. by the way of outgoing line of side surface, effective heat dissipation is realized while also effectively reducing security risks, convenient maintenance and use.

[0025] On the basis of the above technical scheme, the sidewall of the furnace bottom shell 1 is provided with an outlet 5, and the connecting end 6 of the furnace bottom electrode 4 is arranged at the outlet 5. The furnace bottom electrode 4 is provided with a cooling device and is located outside the furnace bottom shell 1.

[0026] On the basis of the above technical scheme, the power supply device comprises an external furnace bus 7 and an automatic current conversion device 8. One end of the external furnace bus 7 is connected with the furnace bottom electrode 4, and the other end is electrically connected with the automatic current conversion device 8. The automatic current conversion device 8 is connected with the power grid.

[0027] By arranging the automatic current conversion device 8, alternating current is rectified into direct current, and the size of the direct current can be changed. By externally applying direct current to increase the furnace bottom current and strengthen the direct current field of the furnace bottom, the bottom molten pool is expanded. The furnace bottom temperature is improved, the cold furnace bottom is avoided, the large-area dead material area is reduced, and the overall melting of the furnace charge is realized. It should be noted that the electric furnace transformer, the short network structure, and the automatic current conversion device mentioned above can be obtained from the prior art, and the present application does not involve improvement of the specific structure thereof.

[0028] On the basis of the above technical scheme, the connecting end 6 comprises a conductive plate 61 and a fastener. The conductive plate 61 is sleeved outside the furnace bottom electrode 4. The conductive plate 61 is provided with a mounting hole, and the fastener is mounted in the mounting hole to press the external furnace bus 7 and the furnace bottom electrode 4.

[0029] On the basis of the above technical scheme, the cooling device is arranged as a cooling water pipe. One end of the furnace bottom electrode 4 located outside the furnace body shell 1 is provided with a cooling groove. A plurality of cooling water pipes are arranged in the cooling groove. Circulating cooling water is introduced into the cooling water pipes.

[0030] In a preferred embodiment, the cooling mode of the furnace bottom electrode 4 selects a water cooling system. Specifically, a long slot is arranged at the end of the furnace bottom electrode, a stainless steel pipe is embedded as a cooling water pipe, heat is taken away by flowing cooling water, and the waterway interface is strictly sealed. More preferably, the cooling water pipe can be arranged in a spiral shape to prolong the flow path of the cooling water, improve the cooling effect, and increase the safety in use.

[0031] In another preferred embodiment, the cooling device is arranged as a cooling water jacket. The cooling water jacket comprises a shell, a water jacket body, an inlet, and an outlet. The shell is sleeved on the water jacket body. The inlet and the outlet are arranged on the water jacket body and are in communication with the cooling water channel inside the water jacket body. More preferably, the cooling water channel is arranged in a spiral shape.

[0032] More preferably, an insulation layer and a sealing layer are arranged between the furnace bottom electrode 4 and the cooling water jacket, the arrangement of the insulation layer can effectively avoid electrode short circuit, and the arrangement of the sealing layer can effectively prevent water leakage of the cooling water jacket and occurrence of danger under high temperature of the electrode.

[0033] By arranging the water cooling structure on the outside of the furnace bottom electrode 4, that is, by arranging circulating cooling water in the cooling water channel, the electrode can be rapidly cooled, and the electrode, especially the graphite electrode, located in the part outside the furnace can be effectively prevented from being oxidized or burned under high temperature, thereby reducing the security risk.

[0034] By arranging the furnace bottom electrode 4 in the side-in and side-out mode, on the one hand, the original furnace body structure can be reduced, the original temperature structure is not changed, the modification is more convenient, and the modification cost is considered; on the other hand, the side-out mode can reduce the security risk that may exist when the furnace bottom electrode is arranged at the bottom, and the safety is higher. At the same time, the cooling device is arranged at the outlet end, and since the furnace bottom electrode adopts the side-out mode, the cooling device can be selected in the water cooling mode, which is convenient to operate, has high cooling speed and high safety. Compared with the case that the outlet end of the furnace bottom electrode is arranged at the bottom end, in order to avoid the security risk that explosion may occur when water cooling is used in the case that the furnace bottom is burned through, in the present application, the use of the direct current electrode with large current at the furnace bottom is prevented by cooperation of the alternating current electrode and the direct current electrode, the risk of burning through the furnace bottom is reduced, and the outlet end of the furnace bottom electrode is arranged at the side of the furnace body. Even if the water cooling mode is used, explosion and other security risks will not occur, and therefore the safety is better.

[0035] On the basis of the above technical scheme, the furnace bottom electrode 4 is uniformly provided with a plurality of electrodes along the circumference of the working layer 3.

[0036] On the basis of the above technical scheme, one end of the furnace bottom electrode 4 close to the center position of the working layer 3 is arranged as an anode, and the electrodes are arranged with an included angle therebetween.

[0037] In this way, on the one hand, the effective heating of the furnace bottom part can be realized, which is beneficial to the distribution of the electric arc between the furnace bottom electrode and the top electrode, and on the other hand, the manufacture of the large-current furnace bottom electrode can be effectively avoided, and the safety of the furnace bottom electrode is higher.

[0038] On the basis of the above technical scheme, the working layer 3 adopts high-thermal-resistance carbon bricks, the heat preservation layer 2 adopts one of heat insulation fibers and light-weight clay bricks, and the furnace bottom shell 1 is made of steel plate. Preferably, the high-thermal-resistance carbon bricks adopt one of magnesium-chromium bricks and magnesium-carbon bricks. The furnace bottom with high-thermal-resistance carbon bricks can effectively protect the furnace bottom while improving the furnace bottom temperature, and balance the performance of the electric conduction efficiency and safety.

[0039] In another aspect, the application also provides a smelting furnace, comprising the conductive hearth structure, and further comprising a furnace body 9, wherein the conductive hearth structure is arranged at the inner bottom end of the furnace body 9, the inner top end of the furnace body 9 is provided with a plurality of top electrodes 10, and the top electrodes 10 are input with alternating current.

[0040] Preferably, the three alternating current electrodes are arranged as the top electrodes 10, and the direct current electrode is arranged as the hearth electrode 4, so that the electric field generated between the alternating current electrodes, the electric field generated between the direct current electrode and the alternating current electrodes, and the electric field generated between the alternating current electrodes and the direct current electrode are distributed, and the electric arc generated after the power is on is used to heat and melt the furnace charge, so that the hot layer distribution can effectively reach the hearth, the high-temperature zone is lowered, the heat dissipation of the material surface is reduced, and the smelting power consumption is expected to be reduced by 10%; the current path is optimized, the current from the electrode to the hearth is effectively increased, and the branch current is reduced; the hearth electrode is arranged, the hearth temperature is increased, the molten pool is developed in width, and the dead material area is reduced; the voltage from each top electrode to the hearth electrode is measured, the distance from each electrode to the hearth is accurately judged, and more accurate furnace control is realized.

[0041] The basic principle and main features of the present application are shown and described above, and it is obvious for those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, so the embodiments should be regarded as exemplary and non-limiting, the scope of the present application is defined by the appended claims rather than the above description, and all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application.

[0042] In addition, it should be understood that although the present application is described in the form of embodiments, not every embodiment contains only one independent technical solution, and the description manner of the specification is only for the sake of clarity, those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be properly combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An electrically conductive hearth structure, characterized in that, The furnace bottom structure comprises a furnace bottom shell, a heat preservation layer, a working layer and furnace bottom electrodes, the heat preservation layer and the working layer are arranged inside the furnace bottom shell from bottom to top, the furnace bottom electrodes are arranged on the working layer and in plurality, one end of the furnace bottom electrodes is arranged on the working layer, the other end penetrates the outer sidewall of the furnace bottom shell and is electrically connected with a power supply device, and the power supply device provides direct current for the furnace bottom electrodes.

2. A conductive hearth structure according to claim 1, wherein The sidewall of the furnace bottom shell is provided with a wire outlet, the connecting end of the furnace bottom electrode is arranged at the wire outlet, and the furnace bottom electrode is provided with a cooling device outside the furnace body shell.

3. A conductive hearth structure as defined in claim 1, wherein The power supply device comprises an external furnace bus and an automatic current conversion device, one end of the external furnace bus is connected with the furnace bottom electrode, the other end is electrically connected with the automatic current conversion device, and the automatic current conversion device is connected with a power grid.

4. A conductive hearth structure as defined in claim 2, wherein The connecting end comprises a conductive plate and a fastener, the conductive plate is sleeved outside the furnace bottom electrode, the conductive plate is provided with a mounting hole, and the fastener is mounted in the mounting hole to press the external furnace bus and the furnace bottom electrode.

5. A conductive hearth structure as defined in claim 2, wherein The cooling device is a cooling water pipe, one end of the furnace bottom electrode outside the furnace body shell is provided with a cooling groove, a plurality of cooling water pipes are arranged in the cooling groove, and circulating cooling water is introduced into the cooling water pipe.

6. A conductive hearth structure as defined in claim 1, wherein The furnace bottom electrodes are uniformly arranged along the circumference of the working layer.

7. A conductive hearth structure as defined in claim 1, wherein The end of the furnace bottom electrode close to the center of the working layer is arranged as an anode and is provided with an included angle between each other.

8. A conductive hearth structure as defined in claim 1, wherein The working layer adopts high thermal resistance carbon bricks, the heat preservation layer adopts one of heat insulation fibers and light weight clay bricks, and the furnace bottom shell is made of steel plate.

9. An electric arc furnace, characterized in that The furnace bottom structure comprises a furnace bottom shell, a heat preservation layer, a working layer and furnace bottom electrodes, the heat preservation layer and the working layer are arranged inside the furnace bottom shell from bottom to top, the furnace bottom electrodes are arranged on the working layer and in plurality, one end of the furnace bottom electrodes is arranged on the working layer, the other end penetrates the outer sidewall of the furnace bottom shell and is electrically connected with a power supply device, and the power supply device provides direct current for the furnace bottom electrodes.

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