JPH02247489A - Flowing nozzle in melting furnace - Google Patents

Abstract

PURPOSE:To assure adjustment of a flow rate and improve responsiveness of the initiation and interruption of the flowing of a molten components for securely assuring the interruption of the flowing by forming a flow passage for a molten substance, etc., in a heat resistant insulator so as for it to penetrate the heat resistant insulator vertically, providing a pair of electrodes for supplying a current to the molten substance, etc., flowing through the flow passage, on the same flow passage horizontally in a confronting relation, and disposing magnetic field generator means in the vicinity of said heat resistant insulator, said magnetic field generator means serving to generate horizontal magnetic fluxes perpendicular to the confronting direction of the pair of the electrodes which magnetic fluxes intersect to each other. CONSTITUTION:Where a current flows through a molten substance, etc., intervened between a pair of electrodes 4 in a direction shown by (+) when the molten substance, etc., have been melted, and where a magnetic flux is generated by a pair of magnetic poles of iron core 9 in a direction of an arrow when magnetic field generator means 5 is actuated, electromagnetic driving force based on the Fleming's left hand law is produced on the molten substance, etc., by said current and said magnetic flux intersecting said current in a direction shown by an arrow F. Thus, the molten substance and the like is subjected to the electromagnetic driving force across its portion through which said current flows in addition to falling force by the weight of the molten substance itself, and hence forcedly moved in the flowing direction of the molten substance.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a melting furnace, and particularly to a flow nozzle that controls the flow of melted material in a melting furnace.

"Prior Art" Generally, in a melting furnace, a material to be melted is placed between opposing electrodes of a melting tank, and f' The melting of the material to be melted is promoted by passing a current between the electrodes to generate resistance heat.

An example of the substance to be dissolved is glass used for solidifying high-level radioactive waste (waste liquid). An example of a solidification treatment plant will be explained based on Fig. 4. Waste such as radioactive waste liquid and materials to be melted are fed into a melting furnace C housed in an airtight chamber B of a cell A and are brought into a molten state. At the same time, radioactive metals, etc. are taken into the melted material, and these melted materials (molten mixture) are passed through the flowing nozzle D.
The required amount is poured into a container (canister) E, and then it is gradually solidified by cooling. A series of solidification processes, including air pollution monitoring for leakage testing, is then carried out.

In addition, in order to flow down and stop the melt, etc., the flow nozzle D is formed of a conductive material such as Inconel 600, and the flow nozzle D is heated to an appropriate temperature by induction heating to maintain a high temperature state. When this happens, the container E is filled by allowing the melt, etc. to flow down, while the induction heating is stopped and the downflow nozzle D is cooled to solidify the glass in the downflow nozzle D and the melt is allowed to flow down. The system is designed to perform controls such as stopping the system.

In addition, the off-gas generated in the melting furnace C when the materials to be melted, etc. are put into the melting tank is suctioned and discharged by an off-gas exhaust pipe F and an off-gas suction and exhaust system G using a blower, etc. It looks like this.

``Problems to be Solved by the Invention'' In such a downstream nozzle D, when the downstream nozzle D is brought to a high temperature state by starting induction heating as shown in FIG. As the temperature rises due to the heat generated by the downstream nozzle D, the melted material becomes molten again and begins to flow down, so after the preparation time T in Figure 5, the flow rate gradually increases and reaches its maximum after a while. It becomes a large amount,
In addition, when stopping the flow of melted material etc. by stopping induction heating, the high temperature melted material etc. continues to flow down from the melting furnace C and heat is supplied, so although the amount of flowing melted material gradually decreases, A phenomenon occurs in which the flowing melt becomes thinner and longer, like a thread, and finally assimilates.

For this reason, the error in setting the amount of dissolved material to be accommodated becomes large, and the workability of accommodating the dissolved material into the container E tends to decrease. In addition, in order to perform induction heating efficiently, it is advantageous to make the nozzle wall thicker to increase the amount of heat generated. However, making the nozzle wall thicker causes a delay in heat transfer and slows down the temperature change. Easy,
On the other hand, if the nozzle wall is made thinner, the amount of heat generated decreases, making control difficult.

The present invention attempts to effectively solve these problems by making it possible to adjust the flow rate, improving the responsiveness of starting and stopping the flow of melt, etc., and ensuring that the flow stops. The purpose is to do so.

In the present invention, in the flow nozzle disposed in communication with the lower part of the melting furnace, a flow path for flowing melt etc. is vertically penetrated through the heat-resistant insulator. A pair of electrodes are formed in the flow path and are horizontally opposed to each other for applying a current to the melt, etc. flowing down therein, and near the heat-resistant insulator,
A magnetic field generating means is provided to intersect magnetic flux in a horizontal direction perpendicular to the direction in which the pair of electrodes face each other.

``Action'' The melt, etc. is brought into a molten state by energizing the pair of electrodes, and by activating the magnetic field generating means, a horizontal magnetic flux perpendicular to the current generated by the pair of electrodes is made to cross the melt, etc. , an electromagnetic driving force based on Fleming's left-hand rule is generated, and the melt, etc. is added to the falling blade due to the load, and it becomes possible to further move it in the downstream direction.

This electromagnetic driving force is obtained in proportion to the product of the amount of current and the strength of magnetic flux, and it becomes possible to adjust the flow rate of the melt, etc.

Furthermore, when the flow of the melt, etc. is stopped, a braking force is generated by applying an electromagnetic driving force upward to quickly stop the flow and lead to a solidified state.

“Example” An example of a melting furnace according to the present invention will be described below with reference to FIGS. 1 to 3.

In FIGS. 1 and 2, reference numeral 1 indicates a nozzle body, 2 a heat-resistant insulator, 3 a downstream passage, 4 a pair of electrodes, 5 a magnetic field generating means, and 6 a furnace wall.

The nozzle main body is made of a conductive material such as Inconel 600, and has a nozzle hole 1a in the center communicating with the lower part of the melting furnace, and a cylindrical part 1b projecting downward from the lower surface of the furnace wall 6. and a flange portion 1c formed at the lower end of the cylindrical portion 1b, and around the cylindrical portion 1b,
An induction heating coil 7 is provided as necessary to re-melt the melted material in the nozzle hole 1a.

The heat-resistant insulator 2 is made of a high-resistance material such as an electrically insulating material made of ceramic, and the flange portion 2a of the heat-resistant insulator 2 is attached to the flange portion 1c of the nozzle body 1 by a fastener 8 such as a bolt or nut and is suspended. At the same time, a flow passage 3 having a rectangular cross-sectional shape, for example, is formed in the center so as to penetrate in the vertical direction.

The pair of electrodes 4 are disposed to face each other in the horizontal direction so that the opposing surfaces are exposed to the flow channel 3.

Further, the magnetic field generating means 5 includes an iron core 9 having a pair of magnetic poles facing each other across the flow passage 3, and magnetizing the iron core 9 in a horizontal direction perpendicular to the opposing direction of the pair of electrodes 4. A magnetic field is generated by direct current magnetization or alternating current magnetization. In the case of direct current magnetization, the current flowing through the pair of electrodes 4 is a direct current, and in the case of alternating current magnetization, the current flowing through the pair of electrodes 4 is a power source of the same frequency, for example, a commercial frequency, whose phase is controlled as described later. Applicable.

When the melting furnace configured as described above is put into operation and the supply of waste materials such as radioactive waste liquid and materials to be melted is started,
As radioactive solids are taken into the melt, an off-gas mixture of water vapor, volatile gas, etc. is generated.

When the melt, etc. (molten mixture) is allowed to flow down,
If necessary, send a high frequency type to the induction heating coil 7,
By induction heating the cylindrical part 1b of the nozzle body I, the solidified substance is melted therein, and further, by applying electricity to the pair of electrodes 4, etc., the melt in the flow path 3 is melted. The electrical conductivity of the material is used to generate resistance and lead to a melted state, and an electromagnetic driving force (described later) is applied upward.

When the melt, etc. is in a molten state, a pair of electrodes 4
The direction of the current flowing through the melted material etc. interposed between the two is the direction shown by ■ in FIG. However, if the direction is indicated by arrow φ in Fig. 2, an electromagnetic driving force based on Fleming's left-hand rule will be applied to the melt etc. as shown by arrow F in Fig. 2 due to the magnetic flux crossing these currents. occurs and acts on As a result, in addition to the falling edge caused by the load of the melted material, etc., an electromagnetic driving force acts on the melted material, etc. in the portion where the current is flowing, and the melted material is forcibly moved in the flow direction.

That is, as shown at timing 1 to timing ii in FIG. 3, when the melt, etc. is held in a stopped state (when the flow rate is 0), the weight of the melt, etc. and the upward driving force are balanced.

however, γ d To: g B.

Place L: It is.

Next, as shown at timing 11 to timing 111 in FIG. 3, when the melt, etc. is made to flow down, the upward electromagnetic driving force is released, and one of the directions of the current or magnetic flux between the electrodes is changed to the inverted glass. Specific gravity Function of the liquid level Rg of the glass; Electrical conductivity of the glass Magnetic flux density When the flow path width of the current glass between the electrodes is changed and a downward electromagnetic driving force (in the direction of arrow F in Fig. The downward movement of the dissolved substances, etc. is switched, and the maximum flow rate is quickly reached.After the downward movement of the dissolved substances, etc. quickly reaches the maximum flow rate,
Since a constant flow of insects continues, it is easier to manage the amount of flow.

In this case, the electromagnetic driving force is obtained in proportion to the product of the amount of current and the strength of the magnetic flux, so by changing either the inter-electrode current or the magnetic flux, the flowing speed of the melt, etc. can be adjusted. become.

In addition, when stopping the flow of dissolved substances, etc., formula (1)
By applying a condition that satisfies the above conditions, that is, applying an upward electromagnetic driving force, it is possible to generate a braking force, quickly stop the flow, and bring the melt etc. to a stopped state. In this stopped state, while maintaining the upward electromagnetic driving force, the induction heating by the induction heating coil 7 is stopped, and the melted material in the nozzle hole 1a of the nozzle body 1 is solidified by cooling from the surroundings. After the magnetic flux is guided, the energization of the pair of electrodes 4 is stopped, and the energization of the coil 10 is stopped to reduce the magnetic flux to O.

In addition, when direct current magnetization is performed, the magnetic field generating means 5 can be constituted by a permanent magnet, and in this case, the electromagnetic driving force is obtained by the current flowing through the pair of electrodes 4. Further, the pair of electrodes 4 and the magnetic field generating means 5 are not limited to the technique shown in the illustrated example, as long as they can pass current in the horizontal direction and provide perpendicular magnetic flux.

[Effects of the Invention J As explained above, according to the falling nozzle of the melting furnace according to the present invention, electromagnetic driving force is generated by energizing the melt and crossing magnetic flux, so that the following excellent effects can be achieved. It becomes something that plays.

(a) By applying an upward or downward electromagnetic driving force to the melt, etc., it is possible to selectively switch between stopping and flowing down the melt, etc., and improving the responsiveness of starting and stopping the flow of the melt, etc. can.

(b) By using electromagnetic driving force, it is possible to quickly raise the flow rate of melt, etc. to the maximum value, and quickly reduce the flow rate to 0, thereby reducing the error in setting the amount of melt stored in the container. can.

(C) The electromagnetic driving force is obtained by the current and magnetic flux between the electrodes, so by changing these, it is possible to adjust the speed of the melt, etc., and the combined effect with the above makes it possible to accommodate the melt, etc. can improve sex.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of the main part showing one embodiment of a downstream nozzle for a melting furnace according to the present invention, Fig. 2 is a view taken along the line ■-■ in Fig. 1, and Fig. 3 is a view similar to Fig. 1. FIG. 4 is a front sectional view showing the concept of a solidification treatment plant, and FIG. 5 is an explanatory diagram of controlling the amount of dissolved matter flowing down in a conventional downstream nozzle. Δ... B... C... D... E... ... Cell, ... Airtight chamber, ... Melting furnace, ... Downstream nozzle, ... Container (canister), F... ...Off gas discharge pipe, G ...Off gas suction and discharge system, 1 ... Nozzle body, 1a ... Nozzle hole, 1b ... Cylindrical part, IC ...Flannel part, 2...Heat-resistant insulator, 2a...Flanne part, 3...Downstream channel, 4...Electrode, 5... ... Magnetic field generating means, 6 ... Furnace wall, 7 ... Induction heating coil, 8 ... Fastener, 9 ... Iron core, IO ... ····coil. Applicant: Power reactor/nuclear fuel development, Ishikawajima-Harima Heavy Industries Co., Ltd. Figure 4

Claims (1)

[Claims] In a flow nozzle disposed in communication with the lower part of the melting furnace, a flow path for flowing melt, etc. is formed in the heat-resistant insulator so as to penetrate in the vertical direction, and the melt flows down through the flow path. A pair of electrodes for passing a current through the melt, etc. are provided in a horizontally opposed state, and a magnetic field generating means for intersecting horizontal magnetic flux perpendicular to the opposing direction of the pair of electrodes is provided near the heat-resistant insulator. A downstream nozzle for a melting furnace characterized by: