JP2006046824A - Discharge nozzle for melting furnace and discharge method of melt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge nozzle for melting furnace facilitating the start of discharge, adjustment of discharge quantity and stop of discharge of a melt, and excellent in durability. <P>SOLUTION: This discharge nozzle comprises a cylindrical nozzle part 20 having a through-hole for discharging a melt molten in a melting furnace, at least part of which is formed of a heating element 21 of induction heating; a fixing plate 31 connected to the nozzle part and having a tap hole 35; and an opening and closing plate 40 variably adjusting the opening area of the tap hole of the fixing plate 31. The start of discharge, adjustment of discharge quantity, and stop of discharge of the melt are performed by using either or both of the heating control by an induction heating means of the nozzle part 20 and the opening area control of the tap hole by the opening and closing plate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a discharge nozzle for discharging a melt of a melting furnace for melting various wastes and the like, and a discharge method of the melt.

  In recent years, as a waste disposal method, it is required not only to incinerate waste, but also to reduce the volume of incinerated ash generated by incineration and make it harmless. Waste incineration ash often contains environmental pollutants (hereinafter collectively referred to as environmental pollutants) such as hazardous heavy metals, radioactive substances, infectious substances, and dioxins. Incinerated ash containing environmental pollutants is designated as specially managed waste, and it is required to be detoxified to a predetermined level by intermediate treatment in order to be reclaimed in a general managed final disposal site. As an intermediate treatment method, four types of melting, cement solidification, chemical treatment and acid extraction are legally recognized. Among them, melting is regarded as most promising in terms of weight reduction, long-term stability, and possibility of recycling.

  There are two methods for discharging the melt melted in the melting furnace: tilting and discharging the melting furnace itself, fixing the melting furnace itself, and providing a discharge nozzle at the bottom or lower side of the furnace, and melting through this discharge nozzle There is a method of discharging things. In the method of tilting and discharging, equipment for tilting is necessary, the discharge of the melt is incomplete and there are many residues, continuous melting cannot be performed, and the processing amount is greatly limited. There are problems such as poor workability. On the other hand, the method using the discharge nozzle does not require equipment for tilting the melting furnace, and can sufficiently discharge the melt, so that there is substantially no residue and can be continuously processed. .

  As a method for discharging a melt (slag) by a discharge nozzle, for example, Patent Document 1 is known. That is, a slag discharge port (discharge nozzle) made of conductive ceramics is provided at the furnace bottom of the melting furnace, and the slag discharge port is heated by induction heating, so that the slag discharge port is closed in advance. The solidified product of slag provided in is melted, and the slag in the melting furnace is discharged. Further, according to this method, after the molten material in the furnace is completely melted by a predetermined heating means, the discharge is performed at one time, and induction heating is stopped at the end of the discharge, and the slag remaining in the discharge nozzle is cooled and solidified. By using a plug, the molten material is prevented from flowing out in an unmelted state when the molten material is charged next time.

However, this method has a problem that part of the material to be melted is discharged in an unmelted state because the generation of the plug is incomplete due to conditions such as slag components, viscosity, and melting temperature. . Furthermore, in the melting stage, the material to be melted in the upper part of the melting furnace may be in a relatively low temperature and unmelted state, and when slag is discharged by the discharge nozzle in such a state, the discharge end stage This unmelted matter remains in the discharge nozzle and is then discharged in an unmelted state.
In addition, this method is a batch-type melting method in which the material to be melted in the furnace is discharged after being melted, and since there is no function for adjusting the discharge amount of slag, continuous operation is difficult.

Further, Patent Document 2 describes another method for discharging the melt using a discharge nozzle. In this method, the molten material in the melting furnace is discharged from a hot water outlet provided on the furnace wall, and a gate member for changing the opening area is provided at the hot water outlet, and the gate member is attached to the molten metal in the furnace. By raising and lowering, the opening area of the hot water outlet is controlled so that the amount of hot water discharged from the melt is always constant. However, after the discharge of the melt is stopped at the gate member, the melt is often cooled and solidified in the discharge nozzle and the outlet, depending on conditions such as the composition of the melt, the viscosity, and the melting temperature. However, when the gate member is opened and discharged after that, there is a problem that the discharge becomes difficult.
JP 2001-343108 A JP-A-2-188435

  As described above, in the conventional discharge nozzle, the melt in the discharge nozzle is not discharged (bath out) while using both the heating means of the melt in the discharge nozzle and the opening / closing means of the discharge nozzle. It is substantially difficult to start the discharge of the melt, adjust the discharge amount, and stop the discharge by controlling the opening of the discharge nozzle with the opening / closing means while controlling the temperature with the heating means. For this reason, the hot water discharge operation of the melt is restricted and causes problems, and the workability is inferior.

  An object of the present invention is to provide a melting furnace discharge nozzle and a melt discharge method that are easy to start discharge of a melt, adjust the discharge amount, and stop discharge, and have excellent durability.

The present invention provides a flow rate adjustment unit that variably adjusts the opening area of the outlet in a cylindrical nozzle portion formed of an induction heating heating element provided in a melting furnace, and performs heating control by induction heating means of the nozzle portion or For the next melting furnace that can start discharge, adjust the discharge amount, and stop discharge of the melt in the melting furnace by using either or both of the opening area control of the hot water outlet by the flow rate adjustment unit Discharge nozzle and melt discharge method are provided.
(1) A through-hole for discharging a melt melted in a melting furnace, a cylindrical nozzle portion at least partially made of a heating element of induction heating, and a tap outlet connected to the nozzle portion A melting furnace discharge nozzle, comprising: a connecting portion; a flow rate adjusting portion that variably adjusts the opening area of the outlet of the connecting portion; and an induction heating means for the nozzle portion.
(2) The discharge nozzle for a melting furnace according to (1), wherein the main part of the connection part is composed of one or more selected from the group consisting of ceramics, refractories and graphite.
(3) The discharge nozzle for a melting furnace according to (1) or (2), wherein the main part of the connection part is made of either ceramics or refractory or both having electrical insulation.
(4) the heating body is a sintered body containing ZrB ₂ 90 to 100% by weight (1), (2) or (3) the melting furnace exhaust nozzles.
(5) From the fixing plate provided with the hot water outlet that communicates with the hot water outlet of the connecting portion, and the opening and closing plate that is slidably connected to the fixing plate and variably adjusts the opening area of the hot water outlet. The discharge nozzle for a melting furnace according to any one of the above (1) to (4), wherein the fixing plate and the opening / closing plate are at least one selected from the group consisting of a metal structure, ceramics, refractory, and graphite.
(6) The discharge nozzle for a melting furnace according to any one of (1) to (5), wherein the fixed plate and / or the opening / closing plate is a metal structure having a water cooling structure.
(7) The molten material in the melting furnace is discharged from the hot water outlet communicating with the cylindrical nozzle part, at least a part of which is a heating element of induction heating, with the flow rate adjusting part varying the opening area of the hot water outlet. In this method, the discharge of the melt is started, stopped, and the discharge amount is adjusted by using either or both of the heating control of the nozzle portion and the opening area control of the outlet by the flow rate adjusting portion. A method for discharging a melt characterized by the above.
(8) While the induction heating of the nozzle part is continued or stopped, the melt in the melting furnace is discharged from the hot water outlet while adjusting the discharge amount of the melt in the flow rate adjusting part, and it matches the discharged melt. The method for discharging a melt as described in (7) above, wherein the material to be melted is put into a melting furnace and continuously melted.

  As described above, the discharge nozzle for the melting furnace of the present invention uses either or both of the heating control by the induction heating means of the nozzle part and the opening area control of the outlet by the flow rate adjusting part, or both. Since the start of the discharge, the adjustment of the discharge amount, and the stop of the discharge are performed, the molten metal can be discharged accurately and smoothly, and the workability is excellent.

  In addition, since the molten metal pouring operation is performed using either or both of the heating control by the induction heating means of the nozzle portion and the opening area control of the pouring gate by the flow rate adjusting portion, the melted material is melted for each melting. A semi-continuous melting operation can be performed by charging the molten material into the melting furnace and repeating this, and a continuous melting operation can be facilitated by continuously charging the melted material corresponding to the discharged melt into the melting furnace.

  In addition, by providing the flow rate adjustment unit in the nozzle unit via the connection unit, the nozzle unit to be induction-heated and the flow rate adjustment unit are separated by the heat insulating layer of the connection unit. The influence of induction heating and the influence of cooling of the flow rate adjusting unit on the nozzle part can be reduced, and the flow rate adjusting part can be electrically insulated from the nozzle part to be induction heated and the influence of the dielectric magnetic field can be reduced.

  In the present invention, the melting furnace is not particularly limited as long as it can melt the material to be melted, and the melting means and the material to be melted are not limited. As the melting means, for example, induction heating, electric melting heating, burner heating or the like can be used. Examples of the material to be melted include those which are melted at a high temperature such as incineration ash, metal, metal alloy, glass, ceramics of daily life and industrial waste.

  The melting furnace discharge nozzle of the present invention (hereinafter referred to as the present nozzle) can be installed in accordance with the melt discharge hole provided at any position on the bottom or side of the melting furnace, and is provided on the side of the furnace. Sometimes, it is preferable to be provided in the lower part of the side wall near the bottom. This nozzle includes a cylindrical nozzle portion having a through hole for discharging the melt in the melting furnace. The shape of the nozzle part is not particularly limited as long as it has a cylindrical shape having a through hole, and is, for example, a cylindrical pipe, a polygonal pipe, or the like. In addition, these pipes may be either straight or tapered (including folds) in the axial direction, and the shape of the through hole is not particularly limited, and may be any of a circle, an ellipse, or a polygon. In the present invention, the cylindrical nozzle portion is not limited to a single unit, but also includes a nozzle portion configured by assembling a plurality of components into a cylindrical shape.

  In the present nozzle, at least a part of the nozzle portion is constituted by an induction heating heating element (hereinafter, simply referred to as a heating element), and the heating hole substantially forms a through-hole for discharging the melt. That is, you may provide the heat retention layer and heat insulation layer which are mentioned later outside a heat generating body. In this way, by forming a through-hole portion that contacts the melt of the nozzle portion with a heating element, the melted material in the nozzle portion is heated to melt from the solidified state when the melt is discharged, and the melt in the melting furnace The material can be discharged, and the melted material can be prevented from cooling and solidifying as necessary.

The material of the heating element is not particularly limited as long as it has heat resistance and corrosion resistance, but a sintered body containing 90 to 100% by mass of ZrB ₂ is particularly preferable because it has a good balance of corrosion resistance, heat resistance, and conductivity. In the following description, all percentages are by mass unless otherwise specified.

  In this nozzle, a heat insulating layer and a heat insulating layer can be provided outside the heating element as described above. It is preferable to provide a heat insulating layer or a heat insulating layer on the outside of the heat generating element because the heating effect of the heat generating element is enhanced, and the durability is improved because the heat generating element is protected by the heat insulating layer or the like. In this case, the effect can be obtained by only one of the heat insulating layer and the heat insulating layer, but a larger effect can be obtained by providing the heat insulating layer on the heat insulating layer. An induction coil for induction heating is attached to the outside of the heat insulating layer or the like. As the material of the heat retaining layer, heat-resistant and thermal shock resistance, for example, alumina-containing low cement castable is suitable, and as the material of the heat insulating layer, alumina fiber, silica fiber, carbon fiber, ceramic fiber, etc. It can be illustrated.

  In addition to the nozzle part, this nozzle is connected to the tip part of the nozzle part, and has a connecting part provided with a hot water outlet that communicates with the through hole of the nozzle part, and a flow rate that variably adjusts the opening area of the hot water outlet of the connecting part It has an adjustment part. That is, a flow rate adjusting part is provided at the tip of the nozzle part, the main part of which is composed of a heating element for induction heating, with a connecting part provided with a hot water outlet, and heating control of the nozzle part by induction heating means. And the hot water discharge operation is performed by controlling the opening area of the hot water outlet by the flow rate adjusting unit.

  In the present nozzle, the connecting portion is a plate-like body or an annular body having a hot water outlet in the center, and is mainly provided as a heat insulating layer between the heating element of the nozzle portion and the fixed plate of the flow rate adjusting portion. In the discharge nozzle in which the nozzle portion has a heating element, the connecting portion plays an important role as a heat insulating layer. In other words, this connecting portion is provided in contact with the heating element and the fixing plate that are at a high temperature, both of which are insulated from each other, and the heating element is damaged by the thermal stress generated by rapid cooling. To prevent. Furthermore, the fixing plate is separated from the heating element and electrically insulated, and the influence of electromagnetic induction of the heating element can be avoided or reduced. Therefore, it is preferable that the main part of the connection part is formed of a heat insulating material having heat resistance, thermal shock resistance and / or electrical insulation. As this heat insulating material, ceramics, refractories, graphite and the like can be preferably used, and one or more selected from the group consisting of these can be used. Here, examples of the ceramic include fine ceramics and cermet, and examples of the refractory include bonded brick, amorphous refractory, electrofused refractory, etc., all of which include a composition partially containing graphite. (same as below).

  In a preferred embodiment of the present nozzle, the flow rate adjusting portion comprises a fixing plate connected to the connecting portion and provided with a hot water outlet, and an opening / closing plate that variably adjusts the opening area of the hot water outlet in cooperation with the fixing plate. it can. The fixing plate has a hot water outlet that communicates with the hot water outlet of the connecting portion, and the hot water outlet communicates with a through hole of the nozzle portion. By attaching the open / close plate to the fixed plate in a slidable or openable manner, the opening area of the hot water outlet of the fixed plate can be made variable (open, partially open, closed), and the discharge work of the melt in the melting furnace can be performed. It can be carried out.

  Since the fixing plate supports at least a part of the load of the nozzle portion through the connection portion and is affected by a high-temperature melt or heating element, it has desired heat resistance and load resistance. In addition, depending on the material, it is necessary to withstand heat generation due to the influence of an induction magnetic field for induction heating of the heating element. Therefore, the material of the fixing plate is appropriately selected according to the temperature of the heating element, the melting point of the melt, the strength of induction heating, and the like. Specifically, it is preferable to use one or more selected from the group consisting of metal structures, ceramics, refractories, and graphite. Among these, for example, a metal structure is suitable as a fixing plate, and a metal structure having a water cooling structure is particularly preferable because it can prevent overheating. The water cooling structure is preferably a water jacket provided with a cooling passage in which a cooling medium is circulated. The metal structure is preferably made of non-magnetic stainless steel, copper, brass or the like because it is not induction heated.

In addition, in the case of discharging hot melt at a high temperature with this nozzle, the outlet portion of each of the fixing plate and the connecting portion, that is, the portion that comes into contact with the melt, is made of, for example, ZrO ₂ which has excellent corrosion resistance. It can be partially formed of an electrocast refractory or fine ceramics.

  The opening / closing plate preferably has a shape that slides in close contact with the fixed plate by a sliding mechanism and can variably adjust the opening area of the outlet of the fixed plate. However, the shape of the opening / closing plate is not limited to this as long as the purpose of variably adjusting the opening area of the outlet of the fixing plate can be obtained. Further, the opening / closing plate sliding mechanism preferably has a structure in which a sliding rail is attached to the fixed plate to ensure the mobility and sealing performance of the opening / closing plate. In particular, by adopting a structure in which the sliding gap between the opening / closing plate and the fixed plate or the sliding rail can be adjusted, it can cope with thermal expansion of the opening / closing plate, wear of the sliding portion, and the like, which can be preferably used.

  The sliding of the opening / closing plate can be performed by a known mechanical drive mechanism. Examples of the mechanical drive mechanism include a linear drive mechanism, a link mechanism, and the like. Particularly, a link mechanism is preferable because remote fine adjustment of the opening / closing plate can be easily performed and operability is excellent. The flow rate of the melt can be controlled by moving the opening / closing plate with a mechanical drive mechanism and changing the opening area of the tap. Specifically, sliding the opening / closing plate to maximize the opening formed by the fixing plate outlet and the opening / closing plate and fully opening the outlet, and adjusting the opening / closing plate to adjust the fixing plate outlet By partially opening the opening and completely closing the outlet of the fixing plate with an opening / closing plate, the discharge amount of the melt can be maximized, the discharge amount of the melt can be variably set, and the discharge of the melt can be stopped.

  When controlling the flow rate of the melt by sliding the opening / closing plate in this way, the opening / closing plate is provided with a circular hole in the opening / closing plate corresponding to the outlet of the fixing plate, and this circular hole is formed on the fixing plate. A type in which the flow rate is controlled by moving relative to the tap, and a type in which the flow rate is controlled by changing the opening area of the tap by moving the tip of the opening / closing plate relative to the tap of the fixed plate (see FIG. 5). And can be broadly divided. The latter type of opening / closing plate is preferably provided with a notch portion such as a V shape or a semicircular shape at the front portion. A practically preferred opening / closing plate has a shape in which the change in the opening area of the tap, that is, the flow cross-sectional area of the melt changes substantially in proportion to the change in the position of the opening / closing plate by the sliding mechanism. Thus, if the movement amount of the opening / closing plate and the change in the flow cross-sectional area of the melt are substantially proportional, the accuracy of the melt discharge control can be improved and the discharge amount can be easily adjusted. The reason why the notch is provided at the tip of the opening / closing plate is also based on such a reason.

  The material of the opening / closing plate varies depending on the temperature of the heating element, the melting point of the melt, the strength of induction heating, etc., and the use temperature of the opening / closing plate can be appropriately selected according to the use temperature and the type of the melt. Specifically, one or more kinds selected from the group consisting of metal structures, ceramics, refractories, and graphite can be used. Particularly, metal structures such as non-magnetic stainless steel, copper, and brass having a water-cooled structure can be used. It can be preferably used. The water cooling structure of the metal structure can appropriately adjust the water cooling effect according to the temperature of the heating element, the melting point of the melt, and the strength of induction heating of the heating element.

  The discharge nozzle for the melting furnace of the present invention uses either or both of the heating control by the induction heating means of the nozzle part and the opening area control of the outlet by the opening and closing plate, or both, to start and discharge the melt. The quantity is adjusted and the discharge is stopped.

Next, a method for discharging the melt by the discharge nozzle for the melting furnace of the present invention will be described with reference to the drawings.
1 and 2 schematically show an example of a semi-continuous melting operation method and a continuous melting operation method using the melting furnace discharge nozzle of the present invention, and the present invention is not limited thereto. In order to make the explanation easy to understand, only the nozzle portion, the fixed plate and the opening / closing plate constituting the flow rate adjusting portion are shown, and the connection portion is omitted.

  1 and 2 show the operating state of the opening and closing plate slidably connected to the nozzle part and the fixed plate installed in the melting furnace, and the operating state described in the figure shows the following states: It is.

  In the nozzle section, the state where the induction heating heating element is not induction heated by the induction heating means is described as “heating stop”, and the state where induction heating is performed is referred to as “heating”. “Stop” operation and “heating” operation.

For open / close plates slidably connected to the fixed plate, the state where the hot plate outlet of the fixed plate is blocked by the non-opening portion of the open / close plate is described as “closed position”, and the hot plate outlet of the fixed plate matches the open portion of the open / close plate. The state to be controlled is described as "open position", and the state in which the flow rate of the melt is controlled by appropriately changing the opening area of the hot water outlet by partially matching the outlet of the fixing plate and the opening of the opening and closing plate is referred to as the "flow adjustment position". ". In the following description, the operations related to each of them are referred to as “closed position” operation, “open position” operation, and “flow rate adjustment position” operation.
The semi-continuous melting operation method using the discharge nozzle for the melting furnace of the present invention will be described step by step with reference to FIG.

  First, a stopper is formed in advance in the through-hole of this nozzle with a solidified product of the melt, and in this state, the material to be melted is put into a melting furnace for operation. The operation is performed in a state of “heating stop” operation and “closed position” operation. (Fig. 1 (A))

  When the object to be melted is melted by the heating means of the melting furnace, a “heat stop” operation and a “closed position” operation are performed. Melting is completed after the melting temperature is maintained for a certain period of time as necessary after reaching a predetermined melting temperature. (Fig. 1 (B))

  After melting is complete, a “heating” operation and an “open position” operation are performed. The plug inside the through hole of the nozzle part (solidified product of the melt) is melted and discharged when the heating element of induction heating reaches a predetermined temperature by the “heating” operation, and then the discharge of the melt in the furnace is performed. Be started. It should be noted that the start timing of the “heating” operation may be performed earlier than the “open position” operation timing if it takes time to raise the temperature of the heating element for induction heating. (Figure 1 (C))

  When the discharge of the melt is started, the “heating” operation and the “flow rate adjusting position” operation are performed to adjust the discharge speed (flow rate). The discharge rate of the melt varies depending on the temperature distribution of the melt in the melting furnace, the surface height of the molten portion, and the like, and can be adjusted by the “flow rate adjustment position” operation. The flow rate can be adjusted more accurately by combining the amount of change in the mass of the melt discharged from the nozzle with time and the position control of the sliding amount of the opening / closing plate. (Figure 1 (D))

  When the discharge of the melt is completed, a “stop heating” operation and a “closed position” operation are performed. Since the melt in the furnace has a relatively low temperature at the top and partly unmelted material, it is desirable to complete the discharge while leaving some hot water in the melting furnace. As a result, the molten material to be charged next can start melting smoothly, and it is excellent in that durability can be maintained by preventing a rapid temperature drop of the in-furnace lining material at the bottom surface of the furnace. The “stop heating” operation may be performed earlier than the “closed position” operation as long as the discharge of the melt is smooth. In addition, it is preferable to know the residual amount of the melt in the furnace by measuring the amount of change in the mass of the melt over time. After the discharge of the melt is completed, the through hole of the nozzle part is filled with the molten slag. (Figure 1 (E))

At the time of charging the next molten material, a “heat stop” operation and a “closed position” operation are performed. In the through hole of the nozzle part, a plug of the solidified product of the melt left in the furnace in FIG. 1 (E) is formed, and the melted material can be melted without being mixed into the through hole. It becomes. (Fig. 1 (F))
The subsequent operation is repeated from FIG. 1 (B) to FIG. 1 (F).

Next, an example of the continuous melting operation method using the discharge nozzle for the melting furnace of the present invention will be described with reference to FIG.
First, a stopper is formed in advance in the through hole of the nozzle with a solidified product of the melt, and the operation is started after the material to be melted is put into a melting furnace. The operation is performed in a state of “heating stop” operation and “closed position” operation. In addition, formation of the plug by the solidified material of the melt is not essential and can be appropriately performed. (Fig. 2 (A))

  When a predetermined amount of material to be melted is put into the melting furnace and melted by the heating means, a “heating stop” operation and a “closed position” operation are performed. Melting is completed after allowing the material to be melted to reach a predetermined melting temperature and maintaining the melting temperature as necessary. (Fig. 2 (B))

  After melting is complete, a “heating” operation and an “open position” operation are performed. The plug inside the through-hole of the nozzle portion is maintained at a high temperature while the melted material in the furnace is melted. Therefore, when the heating element of induction heating reaches a predetermined temperature by the “heating” operation, the plug is melted. And then the discharge of the melt in the furnace is started. In this case, the start timing of the “heating” operation may be performed earlier than the “open position” operation timing if it takes time to raise the temperature of the heating element for induction heating. In addition, in the process of FIG. 2 (A), when the plug was not formed by the solidified product of the melt, when the unmelted material was mixed at the start of the hot water, these unmelted parts were removed and removed. It is desirable that the unmelted material is re-entered into the furnace and completely melted. (Fig. 2 (C))

  When the discharge of the melt starts, perform the "heating" operation and the "flow rate adjustment position" operation to adjust the discharge speed, and at the same time, continuously feed the melt into the furnace in synchronism with the discharge speed. Perform melting operation. Here, the meaning of synchronization means that the mass to be melted is introduced in an amount corresponding to the melting discharge amount in consideration of the mass reduction of ash, moisture, combustion volatile components, etc. in the melt in advance. Specifically, it is desirable to operate so that the level at the time of melting in the furnace is detected and maintained in a substantially constant range. In addition, the above-mentioned quantitative supply amount of the material to be melted and the discharge speed obtained as a result of the flow rate adjustment by this nozzle are the composition, melting point, properties, etc. of the material to be melted and the heating performance of the melting furnace (melting rate, melting temperature, shape) Etc.), an appropriate range is appropriately selected. According to the operation method of this nozzle, it can drive | operate corresponding to the said various conditions. The discharge rate of the melt varies depending on the temperature distribution of the melt in the melting furnace, the surface height of the molten portion, and the like, and can be adjusted by the “flow rate adjustment position” operation.

  Furthermore, in the continuous melting operation, it is preferable to simultaneously control the discharge speed by the “flow rate adjustment position” operation and the control of the quantitative supply amount of the melt. The flow rate can be adjusted more accurately by combining the amount of change in the melt discharged from the nozzle with time and the position control of the sliding amount of the opening / closing plate. In the continuous melting operation, depending on the composition, melting point, properties, etc. of the melt, there is a case where the hot water can be discharged without performing the “heating” operation. In such a case, the “heating stop” operation is performed. it can. (Fig. 2 (D))

  In the continuous melting operation, the operation shown in FIG. 2D is basically performed for a necessary processing period. Further, when the melting operation is stopped after a necessary processing period has elapsed, in FIG. 2 (D), after stopping the quantitative supply of the melted material, a “heating” operation and a “flow rate adjusting position” operation are performed. Alternatively, perform either the “open position” operation to gradually discharge the melt and lower the level of continuous operation.

  When the discharge of the melt is completed, a “stop heating” operation and a “closed position” operation are performed. When a constant amount of melted material is supplied into the furnace in a continuous melting operation, the temperature at the top is particularly low and there is some unmelted material, so discharge is performed with the unmelted material remaining in the melting furnace. Once finished (FIG. 2 (E)), in this state, the unmelted material is completely melted by the heating means of the melting furnace, and then the “heating” operation and the “open position” operation are performed again, whereby the melt in the furnace Can be discharged completely. (Fig. 2 (F))

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 3 is a schematic longitudinal sectional view of the main nozzle fixed to the furnace wall 10 of the melting furnace. 4 and 5 are sectional views taken along lines AA and BB in FIG. 3, respectively, and FIG. 6 is a sectional view taken along line CC in FIG.

  In FIG. 3, the furnace wall 10 of the melting furnace is composed of an inner surface lining material 11 and an outer surface lining material 12, and has a take-out hole 13 for discharging the melt in the melting furnace. The mounting position of the nozzle is not limited to the present embodiment, and can be selected at any position where the take-out hole 13 for discharging the melting furnace is provided, such as the bottom and side portions of the melting furnace.

  This nozzle has a through-hole 29 for discharging the melt, a cylindrical nozzle portion 20 made of at least a part of a heating element 21 of induction heating, and a connection having an outlet 35 connected to the nozzle portion 20. And a flow rate adjusting unit 30 that is slidably attached to an opening / closing plate 40 on a fixed plate 31 having a hot water outlet 35 connected to the connecting portion 32 and connected to the hot water outlet of the connecting portion in the center. The start of the discharge of the melt, the discharge amount using either or both of the heating control by the induction heating means of the nozzle unit 20 and the opening area control of the tap 35 by the opening / closing plate 40 of the flow rate adjusting unit 30 Adjustment and stop of discharge.

  In this nozzle, the nozzle portion 20 is for inductively heating the heating element 21 to the cylindrical heating element 21 with the through-hole 29 formed therein, the cylindrical heat insulating layer 22, the cylindrical heat insulating layer 23, and the outer periphery thereof. The induction coils 24 are arranged in this order from the inside. The nozzle portion 20 is attached to the outer surface lining material 12 of the melting furnace so that the through hole 29 and the extraction hole 13 coincide with each other through a cap 25 covered with the upper end of the heating element 21 and the heat retaining layer 22 for convenience. . Although not shown, an induction power source is connected to the induction coil 24 so that the temperature of the nozzle portion can be controlled by induction heating of the heating element 21.

As shown in FIG. 4, the heating element 21 has a hollow cylindrical shape, and its length and diameter are determined in an optimum range depending on the frequency of the induction power source, the specific resistance of the material, the relative permeability, and the like. For example, when the material of the heating element 21 is ZrB ₂ 100%, it is preferable that the thickness of the hollow cylindrical shape in the radial direction is approximately 20 to 50 mm and the height is 20 mm or more because efficient heat generation is possible.

Since the cap 25 is in direct contact with the melt, a material having excellent corrosion resistance is preferable. For example, an amorphous refractory containing 50 to 100% of ZrB ₂ is preferable because it is excellent in corrosion resistance, easy to form a complicated shape, and economical. In addition, the joint surface of the cap 25 and the outer surface lining material 12 can prevent hot water leakage by providing a mortar joint. The heat insulating layer 22 preferably has heat resistance and thermal shock resistance, and an amorphous refractory is preferable because it can easily form a complex shape and is economical. The heat insulating layer 23 has heat insulating performance at the operating temperature, and preferably can absorb the thermal expansion of the gap between the heat insulating layer 22 and the induction coil 24, and heat resistant fibers, boards, and the like can be preferably used.

  In this nozzle, the fixing plate 31 is substantially formed of a metal structure. Hereinafter, the fixing plate will be described as the metal structure 31. The metal structure 31 has a water cooling structure and is cooled by a cooling pipe and a cooling mechanism (not shown). As the material of the metal structure 31, nonmagnetic stainless steel, copper, brass or the like is preferable because it is not easily affected by induction heating and a good water cooling effect is obtained. In such a metal structure 31, the periphery of the hot water outlet 35 that is in direct contact with the high-temperature melt can be formed by the hot water member 34 having high corrosion resistance against the melt. As the material of the hot water member, metals, ceramics, refractories and the like having excellent corrosion resistance are preferable.

  The connecting portion 32 is provided between the induction heating heating element 21 and the water-cooled metal structure 31. In the discharge nozzle in which the nozzle portion has the heating element 21 as in this nozzle, the connection portion 32 has an important role as a heat insulating layer. That is, the connecting portion 32 is provided in contact with the heat generating element 21 that becomes high temperature and the metal structure 31 that is water-cooled, both of which are insulated from each other, and by the thermal stress generated by rapid cooling. The heating element 21 is prevented from being damaged, and the melt is rapidly cooled around the metal structure 31 to prevent the nozzle from being blocked by the solidified substance. As the material of the connection part 32, ceramics, refractory, graphite and the like can be used as appropriate. In particular, a hot water outlet member 33 is provided around the hot water outlet 35 of the connection part in the same manner as the fixing plate. It is preferable to form with high corrosion-resistant ceramics, refractories and the like.

  The opening / closing plate 40 is attached with a sealing property and a sliding property by a sliding rail 41 installed on the metal structure 31 of the flow rate adjusting unit 30, and can be slid by a driving mechanism 43 through a coupling mechanism 42. The opening / closing plate 40 is moved along the slide rail 41 by the drive mechanism 43, and the hot water outlet 35 provided on the fixed plate 31 is opened or part or all of the hot water outlet 35 is closed by the open / close plate 40. Can be adjusted arbitrarily, including fully open and fully closed.

  The opening / closing plate 40 can be formed of at least one selected from the group consisting of a metal structure, ceramics, refractory, and graphite. In particular, when the opening / closing plate 40 is cooled to a metal structure having a water cooling structure, the metal is oxidized or melted. It is preferable because erosion caused by objects can be reduced and durability can be obtained. When the opening / closing plate 40 has a water cooling structure, cooling is performed by a cooling pipe and a cooling mechanism (not shown).

  The nozzle support structure 50 is performed by fixing and supporting the fixing plate 31 by a supporting member 51 installed on a fixing member 52 provided around the melting furnace. Here, since the nozzle portion expands due to thermal expansion, the support structure 50 follows the change in length, enables the support member 51 to contract, relieves thermal stress on the nozzle portion, and supports with a constant load. A possible structure is preferred. For example, the support member 51 is preferably combined with an elastic body such as a coil spring from the viewpoint of economy. Furthermore, the constituent material of the support structure 50 is usually made of metal or the like, but if it is too close to the induction coil 24, it may generate heat due to the influence of the induction magnetic flux generated around the induction coil 24. It is preferable to use stainless steel or the like.

Example 1
The furnace wall 10 and the nozzle of the melting furnace have the same configuration as that shown in FIGS. As the melting furnace, a high frequency induction heating type melting furnace was used, and a furnace wall 10 of the melting furnace provided with an extraction hole 13 was used. Further, the nozzle is configured to be attached to the furnace wall 10 of the melting furnace through a support member 51 combined with a coil spring from a fixing member 52 that is joined to the frame of the melting furnace so as to absorb thermal expansion.

The nozzle portion 20 of the present nozzle has a cylindrical shape with an inner diameter of 38 mm, an outer diameter of 92 mm, and a length of 250 mm as the heating element 21, a zirconium boride sintered body containing 98% of ZrB _2, and 78% of alumina as the heat retaining layer 22. Contains low-cement castable calcined product, alumina fiber with a maximum operating temperature of 1500 ° C. as the heat insulating material 23, and calcined product of zirconium boride amorphous refractory containing 94% of ZrB ₂ having a take-out hole 13 as the cap 25, respectively. did.
As the induction coil 24, a high-frequency induction coil having an inner diameter of 200 mm and a height of 170 mm was used, and an induction heating power source having an output of 30 kW and a frequency of 2.6 kHz was separately prepared.

The fixing plate 31 of the flow rate adjusting unit 30 is a metal structure made of SUS310 having a thickness of 40 mm and a water cooling structure, the connection portion 32 is a fire resistant material of 30 mm thickness and SiC 70%, and the water cooling structure of the metal structure is formed inside. A plurality of cooling passages were provided, and cooling water was circulated through the cooling passages by a cooling pipe and a cooling device (not shown), and the water was cooled so that the temperature of the cooling water did not exceed 50 ° C. Further, around the hot water outlet of the connecting portion 32, a hot water outlet member 33 made of electrocast bricks having a thickness of 30 mm, an inner diameter of 38 mm, and an outer diameter of 100 mm and containing 94% of ZrO ₂ was provided.

  The open / close plate 40 is a copper metal structure having a thickness of 25 mm and having a water cooling structure. Like the fixing plate, a plurality of cooling passages are provided inside, and the cooling water is passed through the cooling passage and the temperature of the cooling water is 50 ° C. Water-cooled so as not to exceed.

  The opening / closing plate 40 is attached to the sliding rail 41 made of SUS310 attached to the fixed plate (metal structure) 31 of the flow rate adjusting unit 30 with a precision that is slidable and adhesive, and further, a drive mechanism 43 of the opening / closing plate 40. A hydraulic cylinder is used, and the connecting mechanism 42 is connected to the opening / closing plate 40 so that the opening / closing plate can be opened and closed. As shown in FIG. 5, the opening / closing plate 40 has a V-shaped cutout 44 at the tip.

As an object to be melt, the chemical _{components, B 2 O 3 4.1%,} Na 2 O 6.3%, 1.0% MgO, Al 2 O 3 7.9%, SiO2 56.5%, CaO 10 Incinerated ash of 0.7% and Fe ₂ O ₃ 1.9% was used.

  In the melting furnace, the material to be melted was melted by the semi-continuous melting operation method shown in FIG. First, the through hole of the nozzle was previously plugged with a solidified product of the melt, followed by a “stop heating” operation and a “closed position” operation, and 60 kg of incinerated ash was introduced into the melting furnace as the melt. Next, in a state of “stop heating” operation and “closed position” operation, the material to be melted was heated for 80 minutes by the heating means of the melting furnace and melted at about 1400 ° C.

After melting was complete, a “heating” operation and an “open position” operation were performed. Here, the “heating” operation is performed earlier than the “open position” operation timing, and the temperature of the heating element 21 is previously maintained at about 700 ° C. After the “open position” operation, the heating element for induction heating is 1000 by induction heating. Heating was performed at a rate of ° C / h. The plug inside the through hole of the nozzle part was then discharged when the temperature of the heating element 21 reached about 900 ° C., and then the discharge of the melt in the furnace was started.
When the discharge of the melt was started, a “heating” operation and a “flow rate adjusting position” operation were performed, and the discharge speed was adjusted to 5 kg / min.

  Since the melt in the furnace had a relatively low temperature at the top and partly unmelted, left about 10 kg of hot water in the melting furnace and performed “stop heating” and “closed position” operations to discharge the melt. Stopped. At this time, the vicinity of the inner surface lining material 11 of the furnace wall 10 of the melting furnace was coated with the melt, and a sudden temperature drop due to the discharge of the melt was prevented. Furthermore, after the discharge was stopped, the through hole of the nozzle part was filled with molten slag.

  Next, the material to be melted was charged in a state where the “heat stop” operation and the “closed position” operation were performed. At this time, a plug of the solidified product of the melt was formed in the through hole of the nozzle part, and no contamination of the melt was observed.

  Thereafter, the above melting repeated operation was performed 40 times, and the incinerated ash was melted. In each operation of repeated operation, the start of discharge of the melt, adjustment of the discharge amount, and stop of the discharge can be carried out smoothly, and in particular, there is no blockage of the melt in the start of discharge of the melt, adjustment of the discharge amount, and It was confirmed that there was no leakage of the melt when the discharge of the melt was stopped. Further, it was found that the unmelted material was not contained in the melted material after melting.

(Example 2)
The present nozzle having the same configuration as in Example 1 and the material to be melted were used in the continuous melting operation method shown in FIG. First, a stopper is formed in advance in the through hole of the nozzle with a solidified product of the melt, followed by a “stop heating” operation and a “closed position” operation, and 60 kg of incinerated ash as the material to be melted is put into the melting furnace. .

  Next, the “stop heating” operation and the “closed position” operation were maintained, and the material to be melted was heated for 80 minutes with the heating means of the melting furnace and melted at about 1400 ° C. After melting was complete, a “heating” operation and an “open position” operation were performed. Here, the “heating” operation is performed earlier than the timing of the “open position” operation to maintain the temperature of the heating element 21 at about 700 ° C. in advance, and the induction heating heating element is induction heated after the “open position” operation. Was heated at a rate of 1000 ° C./h. Thereafter, the plug inside the through hole of the nozzle portion was discharged when the temperature of the heating element 21 reached about 900 ° C., and then discharge of the melt in the furnace was started.

  When the discharge of the melt is started, the melted material is supplied into the furnace at a rate of 0.75 kg / min by a screw feeder, and at the same time, the "heating" operation and the "flow rate adjusting position" operation are performed. The melt speed was adjusted so that the molten metal surface height maintained the height at the start of the discharge of the melt, and the continuous melting operation was performed. In addition, since there is a decrease in the mass of ash, moisture, combustion volatile components, etc. in the melt with respect to the melt input of 0.75 kg / min, the melt discharge rate corresponds to a 15% reduction in the charge. Was discharged at. Here, in the “heating” operation, induction heating is performed so as to maintain the temperature of the heating element 21 at 900 ° C. If the temperature of the heating element 21 exceeds 900 ° C. during the continuous operation period, the induction heating is performed. Control was performed to stop. Thereafter, the above continuous melting operation was continued to melt 2000 kg of the material to be melted.

  In addition, when the melting process is stopped, after stopping the quantitative supply of the melt, perform the “open position” operation while maintaining the “heating” operation, gradually lower the molten metal level in continuous operation, Discharged. During the continuous melting operation, when a constant amount of melt was supplied into the furnace, the temperature at the top of the furnace was low and some unmelted material was found. The operation and the “closed position” operation were performed and the discharge was once completed. At this time, the vicinity of the inner surface lining material 11 of the furnace wall 10 of the melting furnace was coated with the melt, and a sudden temperature drop due to the discharge of the melt was prevented.

Next, after the unmelted material was completely melted by the heating means of the melting furnace, the “heating” operation and the “open position” operation were performed again to discharge the melt in the furnace.
In this example, the incineration ash was melted by the above operation. In each operation of the operation, it is possible to smoothly start the discharge of the melt, adjust the discharge amount, and stop the discharge, in particular, there is no clogging of the melt in the start of discharge of the melt, adjustment of the discharge amount, and the melting It was confirmed that there was no leakage of the melt when the discharge of the material was stopped. Furthermore, the unmelted material was not contained in the melted material after melting.

  In particular, during the continuous operation of continuous melting, it is possible to adjust the discharge speed so that the molten metal surface height in the melting furnace is maintained at the height at the start of melting, with respect to the quantitative supply of the melt. It can be easily carried out by the “heating” operation and the “flow rate adjusting position” operation, and it has been found that the operation cost is low and the operability is excellent.

  Furthermore, by maintaining the molten metal surface height in the melting furnace constant, it is possible to avoid thermal shock to the inner lining material in the furnace, so that cracks can be prevented, and depending on the upper and lower parts of the molten metal surface Since the oxidation-reduction state in the atmosphere can be kept constant, it is possible to select and use a material with particularly high oxidation resistance at the upper part of the hot water surface of the furnace and a material with particularly high corrosion resistance at the lower part of the hot water surface. Features such as lower operating costs were found.

  According to the present invention, there is provided a hot water outlet by performing either or both of the heating control by the induction heating means of the discharge nozzle portion of the melting furnace and the opening area control of the hot water outlet by the opening / closing plate at the tip of the nozzle portion. Since it is possible to accurately start the discharge of the melt, adjust the discharge amount, and stop the discharge, it can be preferably used in a melting furnace such as incineration ash.

Explanatory drawing which shows the Example of the semi-continuous melting operation method by the discharge nozzle for melting furnaces of this invention. Explanatory drawing which shows the Example of the continuous melting operation method by the discharge nozzle for melting furnaces of this invention. The schematic longitudinal cross-sectional view of the discharge nozzle for melting furnaces which is preferable embodiment of this invention. AA sectional drawing of FIG. The BB arrow line view of FIG. CC sectional drawing of FIG.

Explanation of symbols

10: Furnace wall 11: Inner lining material 12: Outer lining material 13: Extraction hole 20: Nozzle part 21: Heat generating element 22: Thermal insulation layer 23: Heat insulation layer 24: Induction coil 25: Cap 29: Through hole 30: Flow rate adjustment part 31: Fixing plate (metal structure) 32: Connection portion 33, 34: Hot water member 35: Hot water outlet 40: Opening / closing plate 41: Sliding rail 42: Connection mechanism 43: Drive mechanism 44: Notch portion 50: Support structure 51: Support member 52: Fixed member

Claims (8)

  A cylindrical nozzle portion having a through-hole for discharging a melt melted in a melting furnace, at least a part of which is a heating element of induction heating, and a connecting portion connected to the nozzle portion and provided with a hot water outlet And a flow rate adjusting unit that variably adjusts the opening area of the outlet of the connecting portion, and induction heating means for the nozzle unit.   The discharge nozzle for a melting furnace according to claim 1, wherein the main part of the connection part is made of at least one selected from the group consisting of ceramics, refractories and graphite.   The discharge nozzle for a melting furnace according to claim 1 or 2, wherein the main part of the connection part is made of either ceramics or refractory or both having electrical insulation. Melting furnace outlet nozzle according to claim 1, 2 or 3 heating element is a sintered body containing ZrB ₂ 90 to 100% by weight.   The flow rate adjustment part is composed of a fixed plate having a hot water outlet communicating with the hot water outlet of the connection part, and an open / close plate slidably connected to the fixed plate and variably adjusting the opening area of the hot water outlet. The discharge nozzle for a melting furnace according to any one of claims 1 to 4, wherein the plate and the open / close plate comprise one or more selected from the group consisting of a metal structure, ceramics, refractory, and graphite.   The discharge nozzle for a melting furnace according to any one of claims 1 to 5, wherein the fixing plate and / or the opening / closing plate is a metal structure having a water cooling structure.   This is a method in which the melt in the melting furnace is discharged from a hot water outlet that communicates with a cylindrical nozzle part, at least a part of which is an induction heating heating element, by changing the opening area of the hot water outlet with a flow rate adjusting part. The discharge of the melt is stopped, the stop of the discharge, and the discharge amount adjustment are performed by using either or both of the heating control of the nozzle part and the opening area control of the outlet by the flow rate adjustment part, To discharge the melt.   While the induction heating of the nozzle part is continued or stopped, the melt in the melting furnace is discharged from the hot water outlet while adjusting the discharge amount of the melt in the flow rate adjusting part, and the molten material corresponding to the discharged melt The method for discharging a melt according to claim 7, wherein the melt is introduced into a melting furnace and continuously melted.

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