JP5481442B2 - Raw material melting furnace, method for producing glass cullet for optical glass production, and method for producing optical glass - Google Patents

Description

The present invention relates to a raw material melting furnace , a method for producing a glass cullet for producing optical glass, and a method for producing optical glass .

  In the case of producing glass by melting raw materials for glass production, the raw materials are generally charged, heated and melted in a crucible (or a melting tank in which the crucible is scaled up). In addition to this, the raw material is charged from the raw material input port (input port) of the raw material input tube (raw material processing tube) made of quartz glass or the like arranged with the central axis inclined with respect to the horizontal direction. There is also known a method of melting a raw material using a melting furnace that moves the raw material from the inlet side to the outlet side while the raw material is heated and melted in the processing tube and discharges the melt from the outlet (patent) References 1 and 2). In the melting furnaces shown in these Patent Documents 1 and 2, a circular raw material processing tube having a simple shape whose sectional shape with respect to the central axis direction is always constant is used as the raw material processing tube.

  Here, when the raw melt obtained by using the melting furnace described in Patent Document 1 was put into a platinum crucible and the main melt was performed, the raw material before the coarse melt was directly poured into the crucible and melted. Occurrence of leakage of the glass melt due to erosion of the inner wall of the crucible that occurs in some cases can be suppressed. Further, in this melting furnace, by rotating the raw material processing tube with its central axis as the rotation axis, local erosion of the inner peripheral surface of the raw material processing tube can be prevented and the life of the raw material processing tube can be increased. it can. Further, by adjusting the inclination angle of the central axis of the raw material processing tube with respect to the horizontal direction (hereinafter sometimes simply referred to as “inclination angle”), the residence time of the raw material in the raw material processing tube is kept to a minimum and the raw material The erosion of the processing tube can be suppressed as much as possible. The melting furnace described in Patent Document 1 is suitable for manufacturing phosphate glass using a raw material containing orthophosphoric acid.

  Further, when melting is performed using the melting furnace described in Patent Document 2, glass with higher homogeneity can be obtained.

JP-A-62-213027 JP-A-1-119522

  The melting furnaces using the raw material processing tubes exemplified in Patent Documents 1 and 2 described above are currently mainly used for the production of optical glass. Here, the optical glass is manufactured by, for example, a process described below. First, a raw material containing orthophosphoric acid is put into a raw material processing tube made of quartz and heated and dissolved. And the melt which flowed out from the outflow port of a raw material processing tube is thrown into water, and a coarse melt is obtained by quenching. Subsequently, an optical glass is obtained through a step of putting this coarsely melted material into a platinum crucible and performing main melting. The optical glass manufactured by such a process can suppress coloring compared to the optical glass manufactured by the process of melting the raw material directly into the platinum crucible. The reason for this is that the quartz raw material treatment tube is less likely to be eroded by the raw material, and in addition to the case where the main melting is performed using the raw melt, compared to the case where the main melting is performed directly using the raw material, This is because erosion of the inner wall of the platinum crucible can be suppressed and mixing of platinum, which causes coloring, into the optical glass can be suppressed.

  However, when producing a crude melt using the melting furnace exemplified in Patent Documents 1 and 2, the raw material flows out from the outlet while being heated and melted without staying in the quartz raw material processing tube. For this reason, the heating and melting of the raw material tends to be insufficient. In such a case, the corrosiveness of the coarse solution to platinum also increases. Therefore, the optical glass is easily colored when the main melting is performed.

  In order to solve the above-described problem, it is possible to heat and melt the raw material at a higher temperature in the raw material processing tube made of quartz. However, in this case, the degassing of the gas component contained in the raw material becomes significant, so that the gas component contained in the crude dissolved material is reduced, resulting in a deterioration in the clarity during the main dissolution. Therefore, in order to suppress the coloring of the optical glass while ensuring the clarity during the main melting, heating and melting at a relatively low temperature for a longer time in the quartz raw material processing tube. It can be said that it is preferable to be able to.

  However, in the melting furnaces described in Patent Documents 1 and 2, although it is easy to adjust the heating temperature of the raw material moving in the raw material processing tube, it is difficult to adjust the heating time in a longer direction. For example, if the inclination angle is reduced to increase the heating time, the raw material becomes difficult to flow in the raw material processing tube, and the raw material may be clogged in the raw material processing tube, or the raw material may flow backward. In order to increase the heating time without changing the tilt angle, it is also possible to increase the length of the raw material processing tube. However, in this case, since the melting furnace becomes very large according to the length of the raw material processing tube, it lacks practicality. In addition, existing melting furnaces cannot be used.

The present invention has been made in view of the above circumstances, and the raw material is heated and melted in the raw material processing member for a longer time as compared with the conventional raw material melting furnace provided with the raw material processing member for heating and melting the raw material. It is an object of the present invention to provide a raw material melting furnace that is easy to do, a method for producing a glass cullet for producing optical glass using the same, and a method for producing optical glass .

The above-mentioned subject is achieved by the following present invention. That is,
The raw material melting furnace of the present invention is a raw material melting furnace for melting a raw material to produce a glass cullet for producing optical glass . There comprises an outlet for outflow, inlet are arranged to be positioned above the outlet, Ri Do from shape selected from tubular and trough, it is selected from quartz glass, alumina and electroforming brick A raw material processing member composed of a material, and a heating means for heating the raw material moving from the inlet side to the outlet side in the raw material processing member, and at least the raw material processing member in the raw material processing member The present invention is characterized in that a retention portion for temporarily retaining the raw material that moves while being dissolved in the raw material processing member is provided.

  In one embodiment of the raw material melting furnace of the present invention, the raw material processing member is preferably composed of a cylindrical raw material processing tube, and the raw material processing tube is preferably disposed with the central axis inclined with respect to the horizontal direction.

  In another embodiment of the raw material melting furnace of the present invention, the raw material processing tube has at least a cylindrical body and one or more staying portion forming members, and one or more staying portions are formed on the inner periphery of the cylindrical body. It is preferable that the members are fixedly arranged.

  In another embodiment of the raw material melting furnace of the present invention, it is preferable that at least one staying part forming member among the one or more staying part forming members is arranged so as to be in close contact with the inner peripheral surface. .

  In another embodiment of the raw material melting furnace of the present invention, it is preferable that a plurality of block-like staying portion forming members that are substantially in close contact with the inner peripheral surface are arranged along the inner peripheral direction of the cylindrical body.

  In another embodiment of the raw material melting furnace of the present invention, it is preferable that a gap is provided between two block-like staying portion forming members adjacent to each other in the inner circumferential direction of the cylindrical body.

  In another embodiment of the raw material melting furnace of the present invention, the outer peripheral shape substantially coincides with the inner peripheral shape at any position in the central axis direction of the cylindrical body as a staying portion forming member that is substantially in close contact with the inner peripheral surface. It is preferable to use a plurality of annular staying portion forming members.

  In another embodiment of the raw material melting furnace of the present invention, an annular staying part forming member, a pore penetrating in the axial direction of the staying part forming member, and a slit penetrating in the axial direction of the staying part forming member, It is preferable that at least one flow path selected from the above is provided.

  In another embodiment of the raw material melting furnace of the present invention, the outer peripheral shape substantially coincides with the inner peripheral shape at any position in the central axis direction of the cylindrical body as a staying portion forming member that is substantially in close contact with the inner peripheral surface. It is preferable to use individual plate-like staying portion forming members.

  In another embodiment of the raw material melting furnace of the present invention, a plate-like staying part forming member, a pore penetrating in the axial direction of the staying part forming member, and a slit penetrating in the axial direction of the staying part forming member It is preferable that at least one flow path selected from the above is provided.

  In another embodiment of the raw material melting furnace of the present invention, it is preferable that the inner diameter of the cylinder decreases as it goes from the inlet side to the outlet side.

  In another embodiment of the raw material melting furnace of the present invention, it is preferable that the raw material processing tube has at least a cylindrical body, and a convex portion integrated with the cylindrical body is provided on the inner peripheral surface of the cylindrical body. .

  In another embodiment of the raw material melting furnace of the present invention, it is preferable that the raw material processing tube has at least a cylindrical body, and a concave portion is provided on the inner peripheral surface of the cylindrical body.

  In another embodiment of the raw material melting furnace of the present invention, the raw material treatment tube has at least a cylindrical body having a structure in which two or more cylindrical members are joined in series, and an inner peripheral surface of the cylindrical body has At least one step formed by joining one cylindrical member and another cylindrical member and continuous in the circumferential direction is provided, and at least one step among the one or more steps, The inner diameter of the step on the inlet side is preferably larger than the inner diameter of the step on the outlet side.

  In another embodiment of the raw material melting furnace of the present invention, the raw material processing tube has at least a cylinder and a plurality of inhibition members, and the plurality of inhibition members are densely arranged on the inner peripheral surface of the cylinder. It is preferable that they are arranged.

  In another embodiment of the raw material melting furnace of the present invention, the staying portion is a portion where the water depth of the raw material melted in the raw material processing member is locally deep with respect to the longitudinal direction of the raw material processing member. It is preferable.

  In another embodiment of the raw material melting furnace of the present invention, the staying portion is preferably a portion where the flow resistance of the raw material is locally increased with respect to the longitudinal direction of the raw material processing member.

According to the present invention, compared to a conventional raw material melting furnace provided with a raw material processing member for heating and melting a raw material, a raw material melting furnace that can easily heat and melt a raw material for a longer time in the raw material processing member, and The manufacturing method of the glass cullet for optical glass manufacture using this, and the manufacturing method of optical glass can be provided.

It is a schematic diagram which shows an example of the principal part of the raw material melting furnace of this embodiment. It is a schematic diagram which shows an example of the raw material processing pipe | tube used for the raw material melting furnace of this embodiment. Here, FIG. 2 (A) shows an end view when the raw material processing tube is cut along a plane including its central axis, and FIG. 2 (B) is a plan view of the raw material processing tube viewed from the outlet side. It is shown. It is a top view which shows the other example of the raw material processing pipe | tube used for the raw material melting furnace of this embodiment. It is a top view which shows the other example of the raw material processing pipe | tube used for the raw material melting furnace of this embodiment. It is a top view which shows the other example of the raw material processing pipe | tube used for the raw material melting furnace of this embodiment. It is a top view which shows the other example of the raw material processing pipe | tube used for the raw material melting furnace of this embodiment. It is a top view which shows the other example of the raw material processing pipe | tube used for the raw material melting furnace of this embodiment. It is a top view which shows the other example of the raw material processing pipe | tube used for the raw material melting furnace of this embodiment. It is a top view which shows the other example of the raw material processing pipe | tube used for the raw material melting furnace of this embodiment. It is an end view which shows the other example of the cylinder which comprises a raw material processing pipe | tube. It is an end view which shows the other example of the raw material processing pipe | tube used for the raw material melting furnace of this embodiment. It is an end view which shows the other example of the raw material processing pipe | tube used for the raw material melting furnace of this embodiment. It is an end view which shows the other example of the raw material processing pipe | tube used for the raw material melting furnace of this embodiment. It is an end view which shows the other example of the raw material processing pipe | tube used for the raw material melting furnace of this embodiment. It is an end view which shows the other example of the raw material processing pipe | tube used for the raw material melting furnace of this embodiment. It is an enlarged view which shows the state which arranged the obstructive member densely in the retention part shown in FIG. FIG. 16A is a diagram illustrating an initial time point at which the raw material heating / dissolving process is started, and FIG. 16B is an illustration of erosion of the staying portion forming member after the raw material heating / dissolving process is started. It is a figure which shows the time of progressing to some extent. It is an end view which shows an example of the raw material processing tank used for the raw material melting furnace of this embodiment.

  The raw material melting furnace of the present embodiment includes an input port for supplying a raw material for manufacturing a member made of an inorganic material and an outlet for discharging the melted material, and the input port is located above the outlet. A raw material processing member arranged to be positioned and having a shape selected from a cylindrical shape and a bowl shape, and a heating means for heating the raw material moving in the raw material processing member from the inlet side to the outlet side At least, a retention portion is provided in the raw material processing member for temporarily retaining the raw material that moves while being dissolved in the raw material processing member in the raw material processing tube.

  In addition, this residence part is a part (dam type residence part) where the water depth of the raw material melted in the raw material treatment member becomes deep in the longitudinal direction of the raw material treatment member, or the raw material treatment. This is a portion where the flow resistance of the raw material is locally increased with respect to the longitudinal direction of the member (flow resistance increasing type retention portion). Here, the “raw material that has become a melted liquid” refers to a state in which the raw material is not completely melted and solid-liquid mixed when the raw material reaches the vicinity of the retention part in the actual heating and melting process of the raw material, etc. In the case where a flat liquid surface cannot be formed by maintaining the above, the case where it is assumed that the raw material is completely melted when it reaches the vicinity of the staying portion is included. It can be said that the dam-type staying part is the one that maximizes the function of the flow resistance increasing-type staying part.

  For this reason, in the raw material melting furnace of the present embodiment, compared with a conventional raw material melting furnace using a raw material processing tube that does not have any unevenness that temporarily prevents the movement of the raw material in the raw material processing member, the raw material processing member It is easy to heat and dissolve the raw material for a longer time. Therefore, in order to heat and melt the raw material for a longer time in the raw material processing member, there is no need to make the inclination angle smaller than necessary or increase the length of the raw material processing tube. Furthermore, the raw material processing member disposed in the existing melting furnace is replaced with a raw material processing member having the same size as that of the raw material processing member and provided with a retention portion. The raw material can be heated and dissolved for a longer time. For this reason, it is not necessary to significantly modify the existing melting furnace or newly install a new melting furnace.

  The raw material processing member is a long member that can transfer the raw material from the inlet on one end side to the outlet on the other end, specifically, a cylindrical raw material processing tube, or A bowl-shaped raw material processing bowl is used. Here, when a raw material processing tube is used as the raw material processing member, the raw material processing tube is disposed with its central axis inclined with respect to the horizontal direction. In this case, the central axis is inclined with respect to the horizontal direction so that the inlet is located above the outlet. As the raw material processing member, either a raw material processing tube or a raw material processing rod may be used, but it is preferable to use a raw material processing tube from a practical viewpoint. In the following description, the case where a raw material processing tube is used as the raw material processing member will be described. Moreover, the case where a raw material processing rod is used as the raw material processing member will be supplementarily described.

  First, if the retention part has a function of temporarily retaining the raw material that moves while dissolving in the raw material processing tube in the raw material processing tube, the specific configuration for realizing the retention part is particularly limited. is not. However, it is preferable to provide a staying portion in the raw material processing tube by adopting a structure as shown in the following (1) to (6) as the raw material processing tube.

(1) In the case where the raw material processing tube has at least a cylindrical body and one or more staying part forming members, the raw material processing pipe has one or more staying part forming members fixedly disposed on the inner peripheral surface of the cylindrical body. Configuration (first embodiment).
(2) When the raw material processing tube has at least a cylindrical body, a configuration having a convex portion provided on the inner peripheral surface of the cylindrical body so as to be integrated with the cylindrical body (second embodiment).
(3) A configuration in which the raw material treatment tube has at least a concave portion provided on the inner peripheral surface of the cylindrical body when the raw material processing tube has the cylindrical body (third embodiment).

(4) When the raw material processing tube has at least a cylindrical body having a structure in which two or more cylindrical members are joined in series, one cylindrical member and another cylinder are formed on the inner peripheral surface of the cylindrical body. At least one step formed in the circumferential direction and continuous in the circumferential direction is provided, and at least one of the one or more steps has an inner diameter on the inlet side of the step. A configuration (fourth embodiment) configured to be larger than the inner diameter of the step on the outlet side. Here, “joining two or more cylindrical members in series” means an embodiment in which the end face of one cylindrical member and the end face of another cylindrical member are joined, and the inside of one cylindrical member. It means at least one joining mode selected from a mode of joining a part of the peripheral surface and a part of the outer peripheral surface of another cylindrical member.

(5) When the raw material treatment tube has at least a cylinder and a plurality of inhibition members, a configuration in which the plurality of inhibition members are arranged densely on the inner peripheral surface of the cylinder (fifth implementation) Aspect)
(6) Configuration in which two or more types of configurations selected from (1) to (6) above are combined (sixth embodiment)

  In the first embodiment, the region near the inlet side of the retention portion forming member is a retention portion (in which the depth of the melted raw material is locally deepened in the longitudinal direction of the raw material treatment tube ( It is easy to function as a dam-type retention part). Further, when the length of the staying portion forming member with respect to the inner peripheral direction of the raw material processing tube is short, when the height of the staying portion forming member is low, or there is a gap between the staying portion forming member and the inner peripheral surface of the raw material processing tube When it is large, the function as a dam-type staying portion is reduced or eliminated. However, even in such a case, the retention part forming member functions as a retention part (flow resistance increasing type retention part) that locally increases the flow resistance of the raw material in the longitudinal direction of the raw material processing tube. it can.

  In the second embodiment, it is easy to cause the region near the inlet side of the convex portion to function as a dam type staying portion. In addition, if the length of the convex portion with respect to the inner circumferential direction of the raw material processing tube is short or the height of the convex portion is low, the function as a dam type retention portion will be reduced or eliminated, but the flow resistance increased type retention The function as a part can be demonstrated.

  In the third embodiment, it is easy to cause the concave portion to function as a dam-type staying portion. In addition, when the length of the concave portion with respect to the inner peripheral direction of the raw material processing tube is short or the depth of the concave portion is shallow, the function as the dam type staying portion is reduced or disappeared, but the flow resistance increasing type staying portion The function of can be demonstrated.

  In the fourth embodiment, it is easy to cause the region near the inlet side of the step to function as a dam type staying portion. In addition, when the height of the step is low, the function as the dam type staying portion is reduced or lost, but the function as the flow resistance increasing type staying portion can be exhibited.

  In the fifth embodiment, a plurality of inhibitor members arranged densely on the inner peripheral surface of the cylindrical body function as a flow resistance increasing type staying portion. In this case, when the raw material moving along the inner peripheral surface is in a solid state, the movement of the raw material is inhibited by the portion where the obstructing members are densely arranged. Further, when the raw material moving along the inner peripheral surface is a molten liquid, the flow of the raw material is formed between the inhibition member and the inhibition member when passing through the portion where the inhibition members are densely arranged. Or a gap formed between the obstruction member and the inner peripheral surface. For this reason, the flow resistance of the melt raw material is remarkably increased at the portion where the obstructing members are densely arranged, and the flow of the melt raw material is inhibited.

  FIG. 1 is a schematic diagram showing an example of a main part of the raw material melting furnace of the present embodiment. In FIG. 1 and other figures, the double arrow X direction in the figure means the horizontal direction, the double arrow Y direction means the vertical direction, the arrow Y1 direction is the upper side, and the arrow Y2 direction is the lower side. means. Further, in FIG. 1, the description of the specific structure inside the raw material processing tube is omitted.

  A raw material melting furnace 10 shown in FIG. 1 has a raw material processing tube (raw material processing member) 20 and a heating means HT disposed around the raw material processing tube 20. Here, the raw material processing tube 20 is arranged with its central axis C (line C indicated by a one-dot chain line in the figure) inclined with respect to the horizontal direction. Here, the lower limit of the inclination angle θ of the central axis C with respect to the horizontal direction is to select the smallest angle among the angles at which the melt can flow toward the outlet 24 in the raw material processing tube 20. Is preferred. Moreover, it is preferable that the upper limit of the inclination angle θ is an upper limit that does not reach all of the raw materials charged into the raw material treatment tube 20 in the undissolved state. The inclination angle θ is appropriately selected within a range exceeding, for example, 0 °, but is usually preferably within a range of 1 ° to 30 °, more preferably within a range of 1 ° to 20 °. More preferably, the angle is within the range of 10 to 10 degrees.

  Further, heating means HT is disposed on the upper side and the lower side of the raw material processing tube 20. In addition, it is preferable that a part or the whole of the raw material processing tube 20 and the heating unit HT is usually surrounded by a heat-resistant wall material (not shown in the drawing). Further, the arrangement position of the heating means HT with respect to the raw material processing tube 20 and the shape / size / arrangement number of the heating means HT can be appropriately selected from modes other than those exemplified in FIG. Here, the heating method of the raw material can be appropriately selected according to the type of raw material, the material constituting the raw material processing tube 20, the processing conditions of the raw material, etc. For example, the first heating method using radiant heat, heating Two or more types selected from the second heating method by heat conduction from the raw material processing tube 20, the third heating method using electromagnetic induction heating, or the first to third heating methods. A combined fourth heating method can be used. Further, as the heating means HT, known heating means such as a resistance heating element, a far infrared heater, a coil, and a burner can be used.

  Furthermore, the raw material processing tube 20 is particularly preferably rotatable by a driving means (not shown) with the central axis C as a rotation axis. When rotating, the raw material processing tube 20 may be continuously rotated at a predetermined rotation speed, or may be sequentially rotated by a predetermined angle every predetermined time. Moreover, the cross-sectional shape of the raw material processing tube 20 is not particularly limited on both the inner peripheral side and the outer peripheral side, and for example, a circular shape, an elliptical shape, a rectangular shape, or the like can be appropriately selected. In the following description, unless otherwise specified, the raw material processing tube 20 is rotated about the central axis C as a rotation axis, and the cross-sectional shape of the cylinder constituting the raw material processing tube 20 is the inner circumference. The description will be made on the assumption that both the side and the outer peripheral side are circular.

  In addition, when the raw material is heated and melted, the raw material is introduced into the raw material processing tube 20 from the inlet 22 which is an opening on one end side of the raw material processing tube 20. Here, the introduction of the raw material into the raw material processing tube 20 may be carried out continuously or sequentially with a certain time interval. In addition, the raw material can be input manually, but from the viewpoint of preventing variation in the raw material input amount into the raw material processing tube 20 per unit time, it can be automatically performed using a mechanical raw material input device. preferable.

  The raw material (melted material or melt) heated and dissolved in the raw material processing tube 20 to become a molten liquid flows down from the outlet 24 which is an opening on the other end side of the raw material processing tube 20. Here, below the outlet 24, a melting tank such as a crucible for mainly dissolving the melt, or a water tank for rapidly solidifying the melt in water, depending on the purpose of use of the melt or the content of the post-treatment. A metal plate for cooling and solidifying the melt in the air, a molding apparatus for molding the melt into a predetermined shape, and the like can be appropriately disposed.

  Further, at least one staying part (not shown in FIG. 1) can be provided at any position in the raw material processing tube 20 with respect to the central axis C direction. It is preferably provided between the vicinity of the center of the raw material processing tube 20 and the outlet 24.

  FIG. 2 is a schematic diagram showing an example of a raw material processing tube used in the raw material melting furnace of the present embodiment, and specifically shows an example of the first embodiment. Here, FIG. 2 (A) shows an end view when the raw material processing tube is cut along a plane including its central axis, and FIG. 2 (B) is a plan view of the raw material processing tube viewed from the outlet side. It is shown.

  The raw material processing tube 20A (20) shown in FIG. 2 includes one cylindrical tube (cylindrical tube 30A (30)) and eight staying portion forming members 40A (40). Here, eight block-like staying part forming members 40A (40) having the same shape and size are fixedly arranged on the inner wall of the raw material processing pipe 20A (cylindrical pipe 30A). The retaining portion forming member 40A shown in FIG. 2 is manufactured through a step of cutting a ring-shaped member obtained by cutting a cylindrical tube having an outer diameter similar to the inner diameter of the cylindrical tube 30A into eight equal parts. It is a member. In addition, after cutting, in order to adjust the shape and size of the staying portion forming member 40A, the cut surface may be polished or ground as necessary.

  Here, the eight staying portion forming members 40A are located at a position slightly on the outlet 24 (one opening portion of the cylindrical tube 30A) side with respect to the central axis C from the central portion of the raw material processing tube 20A. It arrange | positions along the inner peripheral direction of 30 A of cylindrical tubes so that it may closely_contact | adhere to the inner peripheral surface 26 of (cylindrical tube 30A). In the following description, unless otherwise specified, the arrangement position of the staying portion forming member 40 with respect to the central axis C is assumed to be arranged at the position illustrated in FIG.

  Here, the fact that the retention portion forming member 40 is substantially in close contact with the inner peripheral surface 26 means that a slight gap is formed between the inner peripheral surface 26 and the surface facing the inner peripheral surface 26 of the retention portion forming member 40. Even in this case, it means a state where undissolved raw material lump cannot pass through the gap. In this case, the standard of the maximum width of the gap that prevents the passage of the undissolved raw material lump is 5 mm or less. The maximum width of the gap is more preferably 3 mm or less, and further preferably 1 mm or less. Note that “substantially close” includes a state in which the two surfaces are completely in close contact with each other with no gap. In the following description, for convenience of explanation, it is assumed that the staying portion forming member 40 is disposed in close contact with the inner peripheral surface 26 without any gap except for the example shown in FIG. .

  In the example shown in FIG. 2, a gap W1 is formed between two staying portion forming members 40A adjacent to each other in the inner circumferential direction. This gap length (the length in the circumferential direction) may be adjusted to such a length that the undissolved raw material lump does not pass, and is preferably in the range of 0 mm to 5 mm, and in the range of 0 mm to 3 mm. It is more preferable that the thickness be in the range of 0 mm to 1 mm. By setting the gap length within the above range, when the solid state raw material M (S) flows into the staying part S, the raw material M (S) can be reliably retained in the staying part S. In addition to this, the raw material M (S) in which the raw material M (S) has been dissolved can be temporarily retained in the retention part S and flows out from the retention part S to the outlet 24 side. Can be made. In this case, by appropriately selecting the gap length and the number of gaps W1 provided in the circumferential direction, the outflow amount per unit time of the raw material M (L) flowing out from the staying portion S to the outflow port 24 side can be easily obtained. Can be controlled.

  In addition, as a method of fixing and arranging the retention part forming member 40 on the inner peripheral surface 26 of the raw material processing tube 20, a known fixing method can be appropriately selected. For example, in the example shown in FIG. 2, a chemical fixing method in which the staying portion forming member 40A is bonded to the inner peripheral surface 26 with an adhesive, or the staying portion forming member 40A and the inner peripheral surface 26 are welded or fused. Physical fixing methods can be used. Here, it is preferable that the adhesive is such that the adhesive layer formed by the adhesive has heat resistance at the heating temperature of the raw material and is not easily eroded by a melt obtained by reacting with the raw material or dissolving the raw material. Various mechanical fixing methods can be used as the fixing method. As such a mechanical fixing method, for example, a protrusion for locking the staying portion forming member 40A is provided on the inner peripheral surface 26, and the staying portion forming member 40A is fixed using this protrusion. it can. In this case, by arranging the staying part forming member 40A on the side where the convex inlet 22 is provided with respect to the central axis C, the staying part forming member 40A slides down to the outlet 24 side due to its own weight. It can be fixed so that it can be prevented. Alternatively, holes are provided in the inner peripheral surface 26 and the surface facing the inner peripheral surface 26 of the staying portion forming member 40A, and the staying portion forming member 40A is attached to the inner peripheral surface 26 by inserting pins into these holes. Can be fixed.

  Next, an example of the heating and melting process of the raw material M when the raw material M is charged from the charging port 22 of the raw material processing tube 20A shown in FIG. 2 will be described. First, the raw material M (S) in a solid state is placed on the inner peripheral surface 26 in the vicinity of the inlet 22 by being introduced from the inlet 22 of the raw material processing tube 20A. At this time, the raw material processing tube 20 rotates intermittently or continuously, and the raw material M (S) charged into the raw material processing tube 20 moves to the outlet 24 side while being heated and dissolved. Then, the raw material M (L) in the melt state is temporarily blocked by the staying portion forming member 40A without smoothly moving to the outlet 24 side as it is along the inner peripheral surface 26. Then, the raw material M (L) temporarily stays in the region S0 near the lowermost side in the vertical direction among the regions near the inlet 22 of the staying portion forming member 40A (the staying portion S). In the stay part S, the water depth of the raw material M (L) locally increases with respect to the longitudinal direction of the raw material processing tube 20A. Here, the raw material M (L) staying in the staying part S passes through the gap W1 between the staying part forming members 40A adjacent to each other in the inner circumferential direction and / or rises in the melt surface, for example. By overcoming the upper surface side (the surface on the central axis C side) of the staying portion forming member 40A, it gradually flows down to the outlet 24 side.

  The raw material M is generally a powdered solid material before being put into the raw material processing tube 20, but a coarse particulate solid material, an ingot-shaped solid material, or a paste-like solid material is used. A material, a liquid material, a material obtained by mixing two or more of these materials, and the like can be appropriately selected and used. In addition, the raw material M staying in the staying part S is generally preferably in a liquid state, but is not limited to this, and may be, for example, a mixed state of a solid and a liquid.

  When the raw material M (S) in the solid state is charged into the raw material processing tube 20, the raw material M newly input into the raw material processing tube 20 is a liquid raw material M (L It is preferable that the liquid surface is not covered with the liquid surface. When the newly introduced raw material M (S) is introduced so as to cover the liquid surface of the liquid raw material M (L) that stays in the staying part S, the liquid raw material M ( L) gets over the upper surface side of the staying portion forming member 40A and flows out to the outlet 24 side in a large amount at a time. Thus, when the raw material M (L) temporarily flows out to the outlet 24 side in a large amount, the process of heating and melting the raw material M tends to vary. In addition to this, when the melt flowing down from the outlet 24 is put into a water tank to obtain particles (cullet) made of a coarsely dissolved material, the particle size greatly varies.

  FIG. 3 is a plan view showing another example of the raw material processing tube used in the raw material melting furnace of the present embodiment, specifically, a diagram showing a modification of the embodiment illustrated in FIG. Here, the plan view shown in FIG. 3 is a plan view of the raw material processing tube as seen from the outlet side.

  The raw material processing tube 20B (20) shown in FIG. 3 includes one cylindrical tube 30A and eight staying portion forming members 40B (40). Here, on the inner periphery of the raw material processing tube 20B (cylindrical tube 30A), eight block-shaped staying portion forming members 40B (40) having the same shape and size are fixedly disposed. The staying part forming member 40B shown in FIG. 3 is a member having the same shape, size, and function as the staying part forming member 40A shown in FIG. The eight staying portion forming members 40B are arranged along the inner circumferential direction of the cylindrical tube 30A so as to be in close contact with the inner circumferential surface 26 of the raw material processing tube 20B (cylindrical tube 30A), and in the inner circumferential direction. A gap W2 is formed between the two staying portion forming members 40B adjacent to each other.

  Further, on the inner peripheral side of the eight staying portion forming members 40B arranged in the raw material processing tube 20B so as to constitute one ring, four block members 50 are constituted so as to constitute one ring. Fixed and arranged. The block-shaped member 50 is divided into four equal ring-shaped members obtained by slicing one cylindrical tube, and is appropriately ground so as to be arranged on the inner peripheral side of the eight staying portion forming members 40B. It is a member.

  Here, a gap W3 is formed between two block-shaped members adjacent to each other in the inner circumferential direction. The outer diameter of the ring formed from the four block-like members 50 is substantially the same as the inner diameter of the ring formed from the eight staying portion forming members 40B. For this reason, the block-shaped member 50 and the stay part forming member 40B are substantially in close contact. Further, in the example shown in FIG. 3, four block members 50 are further arranged on the inner peripheral side of the eight staying portion forming members 40B arranged in a ring shape. For this reason, the staying part forming member 40B and the block-like member 50 substantially constitute one partition wall that substantially hinders free movement of the raw material M and air in the direction of the central axis C. Note that the gap lengths of the gaps W2 and W3 are approximately the same as the gap length of the gap W1.

  Here, when the input amount of the raw material M input into the raw material processing tube 20B per unit time is small, only the retention portion forming member 40B functions to temporarily store the raw material M in the raw material processing tube 20B. To demonstrate. This also applies to the staying portion forming member 40A constituting the raw material processing tube 20A shown in FIG.

  On the other hand, in the raw material processing tube 20A shown in FIG. 2, when the input amount of the raw material M introduced into the raw material processing tube 20A per unit time is large, the solid state raw material M (S) that could not be completely dissolved is obtained. It will move over the inner peripheral surface 40AI of the staying part forming member 40A and move toward the outlet 24 side. On the other hand, in the raw material processing tube 20B shown in FIG. 3, when the input amount of the raw material M input into the raw material processing tube 20B per unit time is large, the block-shaped member 50 also supplies the raw material M into the raw material processing tube 20B. The function to make it stay temporarily is demonstrated. That is, the block-shaped member 50 can function as a retention part forming member when the input amount of the raw material M is large.

  Further, in the raw material processing tube 20A shown in FIG. 2, normally, air having a low temperature on the outlet 24 side flows into the raw material processing tube 20A from the outlet 24 side and is arranged in a ring shape in the raw material processing tube 20A. Further, an air flow that passes through the inner peripheral side of the staying portion forming member 40A and moves toward the charging port 22 is easily formed while being heated in the raw material processing tube 20A. For this reason, in the raw material processing tube 20A shown in FIG. However, in the raw material processing tube 20B shown in FIG. 3, the block-shaped member 50 is disposed so as to substantially fill the space of the inner peripheral portion of the staying portion forming member 40B disposed in a ring shape in the raw material processing tube 20B. The flow of airflow from the outlet 24 side to the inlet 22 side is significantly hindered. For this reason, in the raw material processing tube 20B, the heating efficiency of the raw material M can be further improved.

  In the example shown in FIG. 3, a plurality of block-like members 50 are arranged to seal the space on the inner peripheral side of the staying portion forming member 40 </ b> B arranged in a ring shape in the raw material processing tube 20 </ b> B. However, instead of the plurality of block-shaped members 50, one substantially disk-shaped block-shaped member may be arranged.

  FIG. 4 is a plan view showing another example of the raw material processing tube used in the raw material melting furnace of the present embodiment, specifically, a diagram showing a modification of the embodiment illustrated in FIG. Here, the plan view shown in FIG. 4 is a plan view of the raw material processing tube as seen from the outlet side.

  The raw material processing tube 20C (20) shown in FIG. 4 has one cylindrical tube 30A and four staying portion forming members 40C (40). Here, on the inner periphery of the raw material processing tube 20B (cylindrical tube 30A), four block-like staying portion forming members 40C (40) having the same shape and size are fixed in the inner peripheral direction. The gap G1 is fixed and arranged. The four staying portion forming members 40C are 90 relative to the central axis C along the inner peripheral direction of the cylindrical tube 30A so as to be completely in close contact with the inner peripheral surface 26 of the raw material processing tube 20C (cylindrical tube 30A). It is arranged at every degree. In the example shown in FIG. 4, the four staying portion forming members 40 </ b> C are located in the vertical direction and the horizontal direction with respect to the central axis C. In addition, the retention part formation member 40C shown in FIG. 4 passes through the process of cut | disconnecting the ring-shaped member obtained by rounding the cylindrical pipe | tube which has an outer diameter comparable as the internal diameter of the cylindrical pipe | tube 30A in the circumferential direction at fixed intervals. It is the produced member. Here, the gap G1 can be, for example, longer than 0% of the entire circumferential length of the inner peripheral surface 26 and about 3.0% or less.

  In the raw material processing tube 20C shown in FIG. 4, when the input amount of the raw material M introduced into the raw material processing tube 20C per unit time is relatively small, a dam type retention portion is formed by the retention portion forming member 40C. be able to. Here, when the rotation of the raw material processing tube 20C is stopped in the state shown in FIG. 4, the liquid raw material M (S) staying in the staying portion formed by the staying portion forming member 40C is, for example, Depending on the input amount of the raw material M sequentially input from the input port 22 side, it can overflow from both end sides of the retention part forming member 40C and flow toward the outlet port 24 side (first state). Further, the liquid raw material M (S) staying in the staying portion is rotated by 45 degrees in the circumferential direction around the center axis C as the rotation axis with the raw material processing tube 20C being used as a gap between the two staying portion forming members 40C adjacent to each other. To the outlet 24 side at a time (second state). Then, the first state and the second state can be alternately repeated by rotating the raw material processing tube 20C by 45 degrees at regular time intervals.

  FIG. 5 is a plan view showing another example of the raw material processing tube used in the raw material melting furnace of the present embodiment. Here, the plan view shown in FIG. 5 is a plan view of the raw material processing tube as seen from the outlet side.

  The raw material processing tube 20D (20) shown in FIG. 5 includes one cylindrical tube 30A and four staying portion forming members 40D (40). Here, on the inner periphery of the raw material processing tube 20D (cylindrical tube 30A), four block-like retention portion forming members 40D (40) having the same shape and size are fixed in the inner periphery direction. Are arranged. The dwelling part forming member 40D shown in FIG. 5 is a step of cutting a ring-shaped member obtained by cutting a cylindrical tube having an outer diameter similar to the inner diameter of the cylindrical tube 30A into four equal parts in the circumferential direction. It is a member produced through the process. This staying part forming member 40D has an inner surface of the raw material processing tube 20D such that the surface (concave face 40DD) which is the inner peripheral face of the ring-shaped member used for producing the staying part forming member 40D faces the inner peripheral face 26. It is arranged around the circumference. Therefore, a gap G <b> 2 through which the liquid raw material M (L) can easily pass is formed between the concave surface 40 </ b> D of the staying portion forming member 40 </ b> D and the inner peripheral surface 26. Further, the gap G3 through which the liquid raw material M (L) can easily pass between the end surface 40DS of the two staying portion forming members 40D adjacent to each other in the circumferential direction of the inner peripheral surface 26 and the inner peripheral surface 26. Is formed. This end surface 40DS is a cut surface formed when the ring-shaped member used for the production of the retention portion forming member 40D is cut.

  The stay part forming member 40D shown in FIG. 5 forms a flow resistance increasing type stay part that inhibits the flow of the raw material M (S) in the solid state.

  FIG. 6 is a plan view showing another example of the raw material processing tube used in the raw material melting furnace of the present embodiment, specifically, a diagram showing a modification of the embodiment illustrated in FIG. Here, the plan view shown in FIG. 6 is a plan view of the raw material processing tube as seen from the outlet side.

  The raw material processing tube 20E (20) shown in FIG. 6 has one cylindrical tube 30A and one annular staying portion forming member 40E (40) disposed substantially in close contact with the inner peripheral surface 26 thereof. . The outer diameter of the annular staying portion forming member 40E is substantially the same as the inner diameter of the raw material processing tube 20E (cylindrical tube 30A). That is, the outer peripheral shape of the annular staying portion forming member 40E and the inner peripheral shape of the raw material processing tube 20E (cylindrical tube 30A) are substantially in agreement. Note that when the inner diameter of the raw material processing tube 20E (cylindrical tube 30A) is not constant with respect to the central axis C direction, an annular shape is formed at any position in the central axis C direction of the raw material processing tube 20E (cylindrical tube 30A). It is only necessary that the outer diameter of the remaining portion forming member 40E and the inner diameter of the raw material processing tube 20E (cylindrical tube 30A) substantially coincide.

  Here, when the outer diameter of the annular staying portion forming member 40E and the inner diameter of the raw material processing tube 20E (cylindrical tube 30A) completely coincide with each other, the outer peripheral surface 40EO and the inner peripheral surface 26 of the staying portion forming member 40E. Can be brought into close contact with no gap. In this case, the liquid raw material M (S) staying in the staying portion formed by the staying portion forming member 40E is until the water level becomes equal to the inner peripheral surface 40EI of the inner peripheral surface 40EI of the staying portion forming member 40E. Can prevent the raw material M (S) from flowing to the outlet 24 side. Then, after the water level reaches the inner peripheral surface 40EI, the amount of the liquid raw material M (S) corresponding to the amount of the raw material M charged into the raw material processing tube 20E is equal to that of the retention portion forming member 40E. It will flow over the inner peripheral surface 40EI to the outlet 24 side.

  In addition, when the outer diameter of the annular staying portion forming member 40E and the inner diameter of the raw material processing tube 20E (cylindrical tube 30A) do not completely match, there is a minute amount between the staying portion forming member 40E and the inner peripheral surface 26. Gaps are formed. In this case, the liquid raw material M (S) staying in the staying portion flows from the gap to the outflow port 24 side, although it is little by little.

  7 and 8 are plan views showing other examples of raw material processing tubes used in the raw material melting furnace of the present embodiment, specifically, a diagram showing a modification of the embodiment illustrated in FIG. It is. Here, the plan views shown in FIGS. 7 and 8 are plan views of the raw material processing tube as seen from the outlet side.

  The raw material processing tube 20F (20) shown in FIG. 7 has an annular shape provided with a plurality of slits S penetrating in the central axis C direction with respect to the annular staying portion forming member 40E instead of the annular staying portion forming member 40E. Except for the use of the retention part forming member 40F (40), it has the same configuration as the raw material processing tube 20E shown in FIG. Further, the raw material processing tube 20G (20) shown in FIG. 8 has a circular cross-sectional shape penetrating in the central axis C direction with respect to the annular staying portion forming member 40E instead of the annular staying portion forming member 40E. Except for the point that an annular staying portion forming member 40G (40) provided with a plurality of H is used, it has the same configuration as the raw material processing tube 20E shown in FIG. These slits S and pores H function as flow paths for the liquid raw material M (L), and their cross-sectional shape and cross-sectional area depend on the viscosity of the liquid raw material M (L) staying in the staying portion. Are appropriately selected.

  In the example shown in FIG. 7, by appropriately selecting the height and width of the slits S, the number of the slits S, and the arrangement positions in the circumferential direction and the diameter direction, the liquid that stays in the staying portion formed by the staying portion forming member 40F. The outflow amount per unit time of the raw material M (L) can be easily controlled. In the example shown in FIG. 8 as well, by appropriately selecting the diameter and number of the pores H, and the circumferential position and the arrangement position in the diameter direction, the liquid staying in the staying part formed by the staying part forming member 40G. The amount of outflow per unit time of the raw material M (L) can be easily controlled. In the example shown in FIGS. 7 and 8, in order to more accurately control the outflow amount of the raw material M (L) using the slits S and the pores H, the staying portion forming members 40F and 40G and the inner peripheral surface 26 is preferably completely adhered. Moreover, in the example shown in FIG. 7 and FIG. 8, the slit S and the pore H can also be used together as a flow path.

  A plurality of staying portion forming members arranged on the inner peripheral surface 26 so as to form one annular member in the cylindrical tube 30 as in the staying portion forming members 40A and 40B shown in FIGS. When 40A and 40B are used, and when one annular staying part forming member 40E, 40F, and 40G shown in FIGS. 6 to 8 is used, these staying part forming members 40A, 40B, 40E, 40E, 40F, The length (weir height) of the 40G cylindrical tube 30 in the inner diameter direction is preferably 3 mm or more, more preferably 5 mm or more, further preferably 10 mm or more, and more preferably 20 mm or more. Even more preferred. By increasing the height of the weir, it is possible to easily form a dam-type staying portion. The upper limit of the weir height is not particularly limited, and may be less than ½ of the inner diameter of the cylindrical tube 30. From the same viewpoint, the weir height of the staying portion forming member shown in FIG. 4 is also preferably set in the same range as described above.

  FIG. 9 is a plan view showing another example of the raw material processing tube used in the raw material melting furnace of the present embodiment, and more specifically, a diagram showing a modification of the embodiment illustrated in FIG. Here, the plan view shown in FIG. 9 is a plan view of the raw material processing tube as seen from the outlet side.

  A raw material processing tube 20H (20) shown in FIG. 9 includes one cylindrical tube 30A and one disk-like staying portion forming member 40H (40) disposed in close contact with the inner peripheral surface 26 thereof. Have The outer diameter of the disk-like staying portion forming member 40H substantially matches the inner diameter of the raw material processing tube 20E (cylindrical tube 30A). That is, the outer peripheral shape of the disc-like staying portion forming member 40H and the inner peripheral shape of the raw material processing tube 20H (cylindrical tube 30A) are in a substantially identical relationship. When the inner diameter of the raw material processing tube 20H (cylindrical tube 30A) is not constant with respect to the direction of the central axis C, a disc is formed at any position in the central axis C direction of the raw material processing tube 20H (cylindrical tube 30A). It is only necessary that the outer diameter of the retaining portion forming member 40H and the inner diameter of the raw material processing tube 20H (cylindrical tube 30A) are substantially the same.

  In general, it is preferable that the outer diameter of the disk-like staying portion forming member 40H and the inner diameter of the raw material processing tube 20H (cylindrical tube 30A) are completely matched. In this case, the outer peripheral surface 40EO of the staying portion forming member 40H and the inner peripheral surface 26 can be brought into close contact with each other without a gap. For this reason, the outflow amount per unit time of the liquid raw material M (L) staying in the staying part formed by the staying part forming member 40H can be easily controlled only by the slit S provided in the staying part forming member 40H. . In addition, the slit S is provided so that it may penetrate the retention part formation member 40H with respect to the central axis C direction similarly to the case illustrated in FIG.

  In the example shown in FIG. 9, the disk-like staying portion forming member 40H is arranged in the raw material processing tube 20H so that the space in the raw material processing tube 20H is completely divided into two. For this reason, (1) regardless of the input amount of the raw material M per unit time, it is possible to reliably prevent the raw material M (S) that is not sufficiently dissolved from flowing out to the outlet 24 side. it can. In addition to this, (2) it is possible to prevent low-temperature outside air from flowing from the outlet 24 side to the inlet 22 side along the central axis C direction, so the heating efficiency of the raw material M is also high.

  In addition, also in the raw material processing tube 20B shown in FIG. 3, it is possible to obtain substantially the same effect as the effects shown in the above (1) and (2). However, the number of parts constituting the raw material processing pipe 20H is very small compared to the number of parts constituting the raw material processing pipe 20B shown in FIG. Therefore, the raw material processing tube 20H shown in FIG. 9 is easier to assemble than the raw material processing tube 20B shown in FIG. In the example illustrated in FIG. 9, the pores H illustrated in FIG. 8 may be appropriately provided instead of the slit S or together with the slit S.

  In addition, in the raw material processing tube 20H shown in FIG. 9, a disk-like staying portion forming member 40H having a flow path such as a slit S can be disposed at the position closest to the outlet 24 with respect to the central axis C. . Here, as the raw material processing tube 20H having the above-described configuration and the raw material processing tube 20 having substantially the same shape and function, a bottomed cylindrical tube provided with a flow path such as a slit S on the bottom surface portion is used. You can also.

  In the raw material processing tubes 20A, 20B, 20C, 20D, 20E, 20F, and 20G of the first embodiment illustrated in FIGS. 2 to 9, the inner diameter in the direction of the central axis C illustrated in FIG. A cylindrical body (cylindrical tube 30A) is used. However, as the cylinder, a cylinder whose inner diameter in the direction of the central axis C changes with respect to the direction of the central axis C may be used. As such a cylindrical body, it is preferable to use a cylindrical body whose inner diameter decreases as it goes from the inlet side to the outlet side.

  FIG. 10 is an end view showing another example of a cylindrical body constituting the raw material processing tube. In the cylindrical tube 30B (30) shown in FIG. 10, the inner diameter D of the cylindrical tube 30B decreases linearly as it goes from the inlet 22 side to the outlet 24 side. Such a cylindrical tube 30B is a raw material processing tube 20E, 20F, 20G using one staying portion forming member 40E, 40F, 40G, 40H as illustrated in FIGS. 6 to 9 as the staying portion forming member 40. , 20H is suitable. In this case, the outer diameters of the annular staying part forming members 40E, 40F, and 40G and the diameter of the disk-like staying part forming member 40H are smaller than the inner diameter D (in) at the inlet 22 and at the outlet 24. It is larger than the inner diameter D (out). Thereby, when assembling the raw material processing pipes 20E, 20F, 20G, and 20H, if the retention portion forming members 40E, 40F, 40G, and 40H are inserted into the cylindrical pipe 30B from the inlet 22 side, On the other hand, at the point where the inner diameter D coincides with the outer diameter of the staying portion forming members 40E, 40F, and 40G and the diameter of the disc-like staying portion forming member 40H, the staying portion forming members 40E, 40F are simply and mechanically. , 40G, 40H can be fixedly disposed in the cylindrical tube 30B.

  In addition, when the cylindrical tube 30B is arranged in the cylindrical tube 30, the assembly of the raw material processing tubes 20A and 20B using the plurality of block-like staying portion forming members 40A and 40B that substantially constitute one ring. Can also be used. In this case, the outer diameter of the ring constituted by the plurality of block-like staying portion forming members 40A and 40B is smaller than the inner diameter D (in) at the inlet 22 and the inner diameter D (out) at the outlet 24. Larger than. Also in this case, the retention portion forming members 40A and 40B can be fixed and arranged in the cylindrical tube 30B relatively easily and mechanically.

  In the assembling work, for example, the plurality of block-like staying part forming members 40A and 40B can be individually carried to a position where the outer diameter and the inner diameter D of the ring coincide with each other to assemble the ring. Alternatively, using an organic adhesive or jig that is completely pyrolyzed by heating, a ring made of a plurality of block-like staying portion forming members 40A and 40B is prepared in advance outside the cylindrical tube 30B. You may insert a ring to the point where the outer diameter of a ring and the internal diameter D correspond.

  In the case where the cylindrical tube 30B is used as the cylindrical body constituting the raw material processing tube 20, when the inclination angle θ is small, the outflow port of the surface (lowermost surface 26D) located on the lowermost side in the vertical direction of the inner peripheral surface 26. There is a possibility that the inlet 22 side is lower than the 24 side. In such a case, a back flow of the raw material M introduced into the raw material processing tube 20 using the cylindrical tube 30B occurs. Accordingly, the inclination angle θ is set so that the inlet 22 side is higher than the outlet 24 side of the lowermost surface (lowermost surface 26D) in the vertical direction. In this case, the inclination angle θ may be set so as to exceed the angle formed by the lowermost surface 26D and the horizontal direction when the cylindrical tube 30B is arranged with the central axis C aligned with the horizontal direction.

  FIG. 11 is an end view showing another example of the raw material processing tube used in the raw material melting furnace of the present embodiment, and specifically shows an example of the second embodiment. Here, FIG. 11 shows an end view of the raw material processing tube cut along a plane including its central axis.

  The raw material processing tube 20I (20) shown in FIG. 11 has one cylindrical tube 60. A convex portion 62 that is integrated with the cylindrical tube 60 is provided on the inner peripheral surface 26 of the cylindrical tube 60. Here, the convex part 62 is provided continuously in the inner circumferential direction, and the shape thereof is substantially the same as the annular staying part forming member 40E shown in FIG. That is, when the raw material processing tube 20I shown in FIG. 11 is viewed from the outlet 24 side, the shape of the raw material processing tube 20I is the same as the shape shown in the plan view of FIG. And the convex part 62 has the same function as the retention part formation member 40E except for whether it is a member integrated with the cylindrical tube 60 or not. Here, the shape and dimension of the convex part 62 are not limited to the example shown in FIG. 11, and can be suitably selected. Such a cylindrical tube 60 can be produced, for example, by cutting or etching a normal cylindrical tube 30 having no irregularities on the inner peripheral surface 26 as illustrated in FIG.

  In addition, the cylindrical tube 60 illustrated in FIG. 11 can be used instead of the cylindrical tube 30 constituting the raw material processing tubes 20A to 20H of the first embodiment illustrated in FIGS. In this case, the convex portion 62 can be used as a locking member for fixing the staying portion forming members 40 </ b> A to 40 </ b> H in the cylindrical tube 60. Therefore, when the convex portion 62 is used as a locking member, the height of the convex portion 62 may be so low that it is difficult to form the staying portion. In addition, when installing the retention part formation members 40A-40H in the cylindrical tube 60 using the convex part 62 as a locking member, it retains in the cylindrical tube 30 using welding, a fusion | melting, or an adhesive agent. Compared with the case where the part forming members 40A to 40H are installed, the installation work of the staying part forming members 40A to 40H becomes simpler.

  In the raw material processing tube 20I of the second embodiment illustrated in FIG. 11, a convex portion 62 that is integrated with the cylindrical tube 60 is provided in the cylindrical body 60 in advance. For this reason, in the raw material processing tube 20I of the second embodiment, in order to form a retention portion, the retention portion forming members 40A to 40A in the cylindrical tube 30 are formed like the raw material processing tubes 20A to 20H of the first embodiment. The work of installing 40H can be omitted.

  FIG. 12 is an end view showing another example of the raw material processing tube used in the raw material melting furnace of the present embodiment, and specifically shows an example of the third embodiment. Here, FIG. 12 shows an end view of the raw material processing tube cut along a plane including its central axis.

  The raw material processing tube 20J (20) shown in FIG. 12 has one cylindrical tube 70. A recess 72 is provided on the inner peripheral surface 26 of the cylindrical tube 70. Here, the recess 72 is provided continuously in the inner circumferential direction. In the example shown in FIG. 12, the recessed part 72 forms a stay part. Here, the shape and dimensions of the recess 72 are not limited to the example shown in FIG. 12 and can be appropriately selected. Such a cylindrical tube 70 can be produced, for example, by cutting or etching the normal cylindrical tube 30 having no irregularities on the inner peripheral surface as illustrated in FIG.

  Further, in the raw material processing tube 20J of the third embodiment illustrated in FIG. 12, a recess 72 is provided in advance on the inner peripheral surface 26 of the cylindrical body 70. For this reason, in the raw material processing tube 20J of the third embodiment, in order to form a staying portion, the staying portion forming members 40A to 40A in the cylindrical tube 30 are formed like the raw material processing tubes 20A to 20H of the first embodiment. The work of installing 40H can be omitted.

  FIG. 13 is an end view showing another example of the raw material processing tube used in the raw material melting furnace of the present embodiment, and specifically shows an example of the fourth embodiment. Here, FIG. 13 shows an end view of the raw material processing tube cut along a plane including its central axis.

  The raw material processing tube 20K (20) shown in FIG. 13 has one cylindrical body 80. The cylindrical body 80 has a structure in which three cylindrical members, that is, a first cylindrical tube 90, a second cylindrical tube 100, and a third cylindrical tube 110 are joined in series in this order. In the cylindrical body 80, the opening on the side where the first cylindrical tube 90 is disposed becomes the insertion port 22 with respect to the longitudinal direction of the cylindrical body 80, and the side on which the third cylindrical tube 110 is disposed. The opening is an outlet 24.

  Then, in a state where the central axis C1 of the first cylindrical tube 90, the central axis C2 of the second cylindrical tube 100, and the central axis C3 of the third cylindrical tube 110 coincide with each other, The end surface 92 and one end surface 102 of the second cylindrical tube 100 are joined, and the other end surface 104 of the second cylindrical tube 100 and one end surface 112 of the third cylindrical tube 110 are joined. ing. Therefore, the three central axes C1, C2, and C3 constitute the central axis C of the cylindrical body 80. Further, the outer diameter of the first cylindrical tube 90, the outer diameter of the second cylindrical tube 100, and the outer diameter of the third cylindrical tube 110 are the same, and the inner diameter of the second cylindrical tube 100 is The inner diameter of one cylindrical tube 90 and the third cylindrical tube 100 is smaller. The joining method is not particularly limited as long as it is a joining method in which the liquid raw material M (L) does not easily leak to the outside of the cylindrical body 80 via the joining surface, and for example, welding or fusion can be used.

  The inner circumferential surface 26 of the cylindrical body 80 is provided with a first step 120 formed by joining the first cylindrical tube 90 and the second cylindrical tube 100 and continuous in the circumferential direction. A second step 122 formed by joining the second cylindrical tube 100 and the third cylindrical tube 110 and continuous in the circumferential direction is provided. Here, in the first step 120, the inner diameter D1 on the inlet 22 side of the first step 120 is larger than the inner diameter D2 on the outlet 24 side of the first step 120. For this reason, a dam-type stay part can be easily formed in the region of the first step 120 on the inlet 22 side.

  FIG. 14 is an end view showing another example of the raw material processing tube used in the raw material melting furnace of the present embodiment, and specifically shows another example of the fourth embodiment. Here, FIG. 14 shows an end view of the raw material processing tube cut along a plane including its central axis.

  The raw material processing tube 20L (20) shown in FIG. 14 has one cylindrical body 130. The cylindrical body 130 has a structure in which two cylindrical members, that is, a first cylindrical tube 140 and a second cylindrical tube 150 are joined in series. In the cylindrical body 130, the opening on the side where the first cylindrical tube 140 is arranged becomes the inlet 22 with respect to the longitudinal direction of the cylindrical body 130, and the side on which the second cylindrical tube 150 is arranged. The opening is an outlet 24.

  Here, the outer diameter of the second cylindrical tube 150 coincides with the inner diameter of the first cylindrical tube 140. The cylindrical body 130 has a structure in which a part of the inner peripheral surface 142 of the first cylindrical tube 140 and a part of the outer peripheral surface 152 of the second cylindrical tube 150 are joined. That is, the cylindrical body 130 has a structure in which a portion on one end side of the second cylindrical tube 150 is inserted into the inner peripheral side of the first cylindrical tube 140. Therefore, the central axis C1 of the first cylindrical tube 140 and the central axis C2 of the second cylindrical tube 150 constitute the central axis C of the cylindrical body 130. The joining method is not particularly limited as long as it is a joining method in which the liquid raw material M (L) does not easily leak to the outside of the cylindrical body 130 through the joining surface, and for example, welding or fusion can be used.

  The inner circumferential surface 26 of the cylindrical body 130 is provided with a step 160 formed by joining the first cylindrical tube 140 and the second cylindrical tube 150 and continuing in the circumferential direction. Here, in the step 160, the inner diameter D1 of the step 160 on the inlet 22 side is larger than the inner diameter D2 of the step 120 on the outlet 24 side. For this reason, a dam-shaped staying part can be easily formed in the region of the step 160 on the side of the inlet 22.

  In addition, in the raw material processing tube 20L shown in FIG. 14, the bonding area between the two cylindrical members 140 and 150 constituting the cylindrical body 130 can be increased in the raw material processing tube 20K shown in FIG. Is easy to secure. In addition, the cylindrical body 130 has a structure in which the second cylindrical body 150 is inserted on the inner peripheral side of the first cylindrical member 140. Therefore, the cylindrical body 130 is not easily broken by a mechanical impact or stress applied from a direction substantially orthogonal to the central axis C of the cylindrical body 130.

  Further, in the raw material processing tubes 20K and 20L of the fourth embodiment illustrated in FIGS. 13 and 14, steps 120 and 160 forming a staying portion are provided in the cylinders 80 and 130 in advance. For this reason, in the raw material treatment tubes 20K and 20L of the fourth embodiment, in order to form a retention portion, the retention portion forming member is formed in the cylindrical tube 30 like the raw material treatment tubes 20A to 20H of the first embodiment. The work of installing 40A to 40H can be omitted.

  FIG. 15 is an end view showing another example of the raw material processing tube used in the raw material melting furnace of the present embodiment, and specifically shows an example of the fifth embodiment. Here, FIG. 15 shows an end view of the raw material processing tube cut along a plane including its central axis.

  The raw material processing tube 20M (20) shown in FIG. 15 has one cylindrical tube 30A (30) and a plurality of inhibiting members 170. Here, the plurality of inhibiting members 170 are densely arranged on the inner peripheral surface 26 of the raw material processing tube 20M (cylindrical tube 30A). In the example shown in FIG. 15, the plurality of inhibiting members 170 are densely arranged near the center in the longitudinal direction of the raw material processing tube 20M, but the longitudinal direction of the raw material processing tube 20M. On the other hand, it can arrange | position densely in arbitrary positions.

  Here, the raw material M (S) in the solid state can be dammed at the inlet 22 side of the portion where the plurality of blocking members 170 are densely arranged. Further, when the raw material M (L) in the liquid state passes through a portion where the plurality of blocking members 170 are densely arranged, the flow resistance is remarkably increased. Therefore, the raw material M temporarily stays in the vicinity of the portion where the plurality of blocking members 170 are densely arranged.

  The size, size distribution, and shape of the inhibition member 170 are not particularly limited, and any size can be selected as long as it can be densely arranged in the raw material processing tube 20M. The size that can be densely arranged in the raw material processing tube 20M means that the average value (average maximum diameter) of the maximum diameters of the individual inhibiting members 170 is at least about 1/10 or less of the inner diameter of the raw material processing tube 20M. Means that.

  However, in order to more effectively inhibit the movement of the raw material M in the raw material processing tube 20M, it is necessary to increase the density of the inhibiting member 170 (the volume ratio occupied by the inhibiting member 170 per unit volume) to some extent. From such a viewpoint, the average maximum diameter of the inhibiting member 170 is preferably about 5 mm to 50 mm. When the average maximum diameter is increased, it is preferable to increase the size distribution. In this case, since the small-sized inhibitory member 170 can be disposed in the gap between the large-sized inhibitory members 170, the degree of congestion can be increased. In addition, as the shape of the inhibition member 170, an arbitrary shape can be selected, and for example, a spherical shape, a rod shape, a polyhedron shape, a cylindrical shape, or the like can be used. Further, in order to more effectively inhibit the movement of the raw material M, the number of inhibiting members 170 used is preferably 5 or more, and more preferably 10 or more. The upper limit of the number of inhibiting members 170 to be used is not particularly limited, and can be appropriately selected according to the maximum diameter of the inhibiting member 170 and the inner diameter of the raw material processing tube 20M. preferable.

  Unlike the staying portion forming member 40, the inhibiting member 170 is not fixedly disposed at a specific position on the inner peripheral surface 26 of the raw material processing tube 20M. That is, when the raw material processing tube 20 rotates, the inhibition member 170 moves along the inner peripheral surface 26 due to its own weight, and when the external force generated by the contact with the raw material M moving in the raw material processing tube 20 is large. Also, the inhibition member 170 moves along the inner peripheral surface 26. For this reason, when the input amount of the raw material M per unit time is large, when the inclination angle θ is large, or when the weight of the individual inhibiting member 170 is small, the inhibiting member 170 is pushed toward the outlet 24 side. It becomes easy. In this case, with the passage of time, the inhibiting member 170 disposed in the raw material processing tube 20M falls from the outlet 24 side and is gradually lost (first problem).

  On the other hand, in the first embodiment to the fourth embodiment, the staying portion forming member 40 in the first embodiment (however, except for the staying portion forming member 40D arranged in a manner not substantially in close contact with the inner peripheral surface 26). The convex portion 62 in the second embodiment and the steps 120 and 160 in the fourth embodiment having substantially the same function as the stay portion forming member 40 (excluding the stay portion forming member 40D), and the third embodiment. When the inner peripheral surface 26 on the outlet 24 side of the concave portion 72 of the inner peripheral surface 26 near the concave portion 72 is eroded by the heated melted raw material M (L), the liquid raw material M (L) is The function of temporarily staying in the raw material processing tube 20 may deteriorate over time (second problem).

  In order to solve the first problem and the second problem described above at the same time, the staying portion forming member 40 (excluding the staying portion forming member 40D), the convex portion 62, and the steps 120 and 160 on the inlet 22 side. It is preferable that the plurality of inhibition members 170 be densely arranged in a stay portion that is a liquid pool to be formed or a stay portion that is a liquid pool consisting of the recesses 72. That is, it is preferable to use the fifth embodiment in combination with any one of the first to fourth embodiments. In this case, even if some external force is applied to the obstruction member 170, it becomes difficult for the obstruction member 170 to move out of the staying portion. Therefore, the first problem can be easily solved or the occurrence can be prolonged. It can be suppressed over.

  In addition, it is easy to suppress the occurrence of the second problem over a longer period. The reason for this will be described as a specific example, as shown in FIG. 16, in the case where the inhibiting member 170 is disposed in the staying portion S of the raw material processing tube 20 </ b> A. FIG. 16 is an enlarged view showing a state in which the inhibiting members 170 are densely arranged in the staying part S (S0) shown in FIG. 2, and shows the structure of the staying part S and the raw material processing tube 20A in the vicinity thereof. It is a thing. Here, FIG. 16A is a diagram illustrating an initial time point at which the heating / dissolving process of the raw material M is started, and FIG. It is a figure which shows the time of erosion of the part formation member 40A progressing to some extent.

  First, when the inhibiting member 170 is arranged in the raw material M (L) staying in the staying part S (S0), it is placed in the staying part S at the initial stage when the heating / dissolution treatment of the raw material M is started. The blocked member 170 is only immersed in the liquid raw material M (L), and the function of temporarily retaining the raw material M in the raw material processing tube 20A is not so much exhibited. This is because the flow resistance of the liquid raw material M (L) is maximized not in the gap between the inhibition members 170 but in the gap formed by the two staying portion forming members 40A adjacent to each other in the inner circumferential direction. is there.

  However, when the raw material M (L) staying in the staying part S has a property of eroding the staying part forming member 40A, if the heating and dissolution of the raw material M are continued for a long time, the staying part The forming member 40A is gradually eroded. For this reason, the width of the gap formed by the two staying portion forming members 40A adjacent to each other in the inner circumferential direction gradually increases. The flow resistance in this gap is greatly reduced. Therefore, the retention function of damming the liquid raw material M (L) by the retention portion forming member 40A decreases with time. And the liquid level F of the raw material M (L) which retains in the retention part S begins to fall. However, in this case, the liquid raw material M (L) flows through the gap between the inhibition members 170 while receiving resistance.

  Moreover, even if the inhibiting member 170 is eroded by the raw material M (L) that stays in the staying part S, the inhibiting members 170 whose sizes are somewhat reduced by erosion fill the gaps between each other. Can be moved to. For this reason, the gap formed between the obstruction members 170 does not substantially expand regardless of the passage of time. In other words, the flow resistance of the portion where the blocking members 170 are densely arranged hardly decreases with time. Here, in order to prevent an increase in the gap between the inhibiting members 170 whose sizes are slightly reduced by erosion, it is particularly preferable to rotate the raw material processing tube 20A about the central axis C as a rotation axis in a timely manner.

  Therefore, when the flow resistance in the gap portion formed by the two staying portion forming members 40A adjacent to each other in the inner circumferential direction decreases and falls below the flow resistance of the portion where the blocking members 170 are densely arranged. The portion where the blocking members 170 are densely arranged can start to exhibit the function of retaining the liquid raw material M (L). For the reason described above, the occurrence of the second problem can be easily suppressed over a long period of time by arranging the inhibition members 170 in the staying portion S in a dense manner.

Next, the constituent material of each member which comprises the raw material processing pipe | tube 20 demonstrated above is demonstrated. The materials constituting the cylindrical bodies 30, 70, 80, 130, the retention portion forming member 40, and the block-shaped member 50 constituting the raw material processing tube 20 include the composition of the raw material M to be heated / dissolved, conditions can be suitably selected according to the intended use or the like of lysates obtained by heating and dissolving treatment raw material M, for example, it can be used quartz glass, alumina, etc. electrostatic Ineri tiles. Here, examples of the electroformed brick include AZS-based and Zr-based bricks. In addition, although it is preferable that each member which comprises the raw material process pipe | tube 20 is comprised from the same material, you may be comprised from a mutually different material. Further, the surface of each member constituting the raw material processing tube 20 is subjected to a coating treatment or a sheet-like member pasting treatment as necessary in order to ensure corrosion resistance, heat resistance, etc. with respect to the raw material M. May be.

The raw material M is not particularly limited as long as the raw material M is used for manufacturing a member made of an inorganic material, and in addition to the inorganic component, an organic component such as a binder that decomposes and disappears by heating, A gas component or the like may be contained in a form contained in a solid material such as carbonate. Here, parts material made of an inorganic material is a crude lysate used to produce the optical glass (glass cullet for optical glass production (also referred to as "optical glass for manufacturing crude lysate")), the raw material M is It is a raw material for producing optical glass.

In addition, the coarse melt | dissolution for optical glass manufacture is a coarse melt for main melt | dissolution at the time of manufacturing optical glass.

When manufacturing the optical glass for manufacturing crude lysate Here, as a material for optical glass Manufacturing, a raw material containing a component (gas-containing component) to generate gas by heating, such as carbonates and hydroxides Use. In this case, if the raw material melting furnace 10 of the present embodiment is used, it is possible to easily obtain a crude melt for producing optical glass containing an appropriate gas component to ensure the clarity of the glass melt during the main melting. it can. The reason for this is as follows. First, in the raw material melting furnace 10 of the present embodiment, the residence time of the raw material M in the raw material processing tube 20 can be controlled more easily than the conventional raw material melting furnace. Therefore, when the raw material M contains a gas-containing component, the amount of degassing from the raw material M during heating and melting can be controlled more accurately.

  The raw material melting furnace 10 of the present embodiment is particularly preferably used for producing a phosphate-based crude melt for producing optical glass. In this case, since the raw material melting furnace 10 of the present embodiment can heat and melt the raw material M at a lower temperature and for a longer time than the conventional raw material melting furnace, the clarity during the main melting is improved. While ensuring, coloring of optical glass can also be suppressed. When the raw material contains any of a Ti compound, Nb compound, Bi compound, and W compound in addition to the phosphate, when the raw material M is heated at a high temperature, the optical glass is more colored by reducing these metals. May be promoted. However, even in such a case, if the raw material melting furnace 10 of the present embodiment is used, the amount of gas components contained in the crude melt is clarified while heating the raw material at a relatively low temperature so that reduction of these metals does not occur. Heat treatment can be performed for a long time so as to be in a range suitable for securing the property. For this reason, the clarity at the time of this melt | dissolution can also be ensured easily, suppressing coloring of optical glass.

In addition, when using the raw material melting furnace 10 of this embodiment for manufacture of the coarse melt for optical glass manufacture, as a constituent material of each member which comprises the raw material process tube 20, the rough melt for phosphate type | system | group optical glass manufacture is used. for things have preferably be used quartz glass.

  In addition, quartz glass is used as a constituent material of each member constituting the raw material processing tube 20, in particular, a material constituting the cylindrical bodies 30, 70, 80, and 130, and the heating method of the raw material M has at least radiant heat by infrared rays When used, the content of hydroxyl groups contained in the quartz glass used is preferably as small as possible. In this case, since the infrared transmittance of quartz glass can be further increased, the heating efficiency by radiant heating can be further increased. In addition, since the quartz glass is difficult to be deteriorated and deteriorated by long-term heating, the life of the raw material processing tube 20 can be extended.

  Next, the case where a raw material processing rod is used as the raw material processing member will be described. In this case, the raw material processing rod has at least a casing (or a substantially half-cylindrical body) composed of a lower side portion of the cylindrical body instead of the cylindrical body constituting the raw material processing tube 20. Except for this point, the structure and material of the raw material treatment vessel can be the same as that of the raw material treatment tube 20. In addition, when using the retention part formation member 40, the retention part formation member 40 should just be arrange | positioned in the position which contacts or opposes the internal peripheral surface of a housing at least. Further, a part of the raw material treatment basket in the longitudinal direction may have the same configuration as that of the cylindrical body.

  The raw material melting furnace using the raw material processing furnace as the raw material processing member heats the raw material M for a longer time in the raw material processing furnace like the raw material melting furnace of this embodiment using the raw material processing pipe as the raw material processing member. -It is easy to dissolve. In addition, when using the raw material processing rod, it is not necessary to rotate the central axis C as the rotation axis. In addition, the raw material processing trough has a structure with an open top. For this reason, maintenance is extremely easy when the raw material processing tank is repeatedly used. For example, it is very easy to remove the raw material M adhering to the inner peripheral surface of the raw material treatment bar or replace the staying part forming member 40 whose function of forming the staying part S is significantly reduced by erosion.

  In addition, as a cross-sectional shape of the housing of the raw material processing rod, for example, it can be the same as the cross-sectional shape of a member obtained by dividing the cylindrical body constituting the raw material processing tube 20 into two along its longitudinal direction. . In addition, a known shape functioning as a collar, such as a V-shaped groove shape or a U-shaped groove shape, can be appropriately selected.

  FIG. 17 is a schematic cross-sectional view showing an example of a raw material treatment furnace used in the raw material melting furnace of the present embodiment, and is a plan view of the raw material treatment furnace as viewed from the outlet side. A raw material processing rod (raw material processing member) 200 shown in FIG. 17 has the same structure as one of the members obtained by substantially dividing the raw material processing tube 20B shown in FIG. It is what you have. That is, the raw material processing rod 200 has a casing (semi-cylindrical tube) 210 obtained by dividing the cylindrical tube 30A into two by a plane including the central axis C. Further, four staying portion forming members 40 </ b> B are arranged along the inner peripheral direction of the casing 210 so as to be in close contact with the inner peripheral surface of the casing 210. Further, two block members 50 are fixedly arranged on the inner peripheral side of the four staying portion forming members 40B. In the raw material melting furnace shown in FIG. 1, the raw material processing tube 200 can be used instead of the raw material processing tube 20.

  Hereinafter, the present invention will be described with reference to examples. However, the present invention is not limited to the following examples.

(material)
A raw material for producing phosphate-based optical glass having the following composition was prepared in terms of oxide after excluding components gasified by heating such as water and carbon dioxide from the raw material. In preparing the raw materials, among the components shown below, for P ₂ O ₅ , orthophosphoric acid (H ₃ PO ₄ ), metaphosphoric acid, phosphorous pentoxide or the like is used, and for other components, carbonic acid is used. Salts, nitrates, oxides and the like were used.
P ₂ O ₅ : 20% by mass
Nb ₂ O ₅ : 43% by mass
BaO: 19.5 mass%
B ₂ O ₃ : 3% by mass
TiO ₂ : 8% by mass
Na ₂ O: 3.5% by mass
K ₂ O: 1% by mass
ZnO: 1% by mass
ZrO ₂ : 1% by mass
Total: 100% by mass
Add 0.3% by mass of Sb ₂ O ₃

Example 1
-Raw material melting furnace-
As the raw material melting furnace 10, the one provided with the raw material processing tube 20B shown in FIG. 3 was used. All the constituent materials of the raw material processing tube 20B are made of quartz glass. Here, the dimensions and shape of the cylindrical tube 30A are length: 100 cm, outer diameter: 10 cm, inner diameter: 8 cm, and the retention portion forming member 40B is a ring-shaped member having a thickness: 5 cm, an outer diameter: 8 cm, and an inner diameter: 6 cm. After being equally divided into eight in the circumferential direction, the shape is appropriately adjusted so that it can be easily placed in the cylindrical tube 30A. Further, the block-shaped member 50 is formed by dividing the ring-shaped member having a thickness of 5 cm, an outer diameter: 6 cm, and an inner diameter: 4 cm into four equal intervals in the circumferential direction, and then the staying portion forming member 40B arranged in a ring shape. The shape is appropriately adjusted so that it can be easily arranged on the inner peripheral side. Here, the gaps W2 and W3 are about 1 mm. The staying part forming member 40B and the block-like member 50 were disposed at a position of about 20 cm from the outlet 24 side of the raw material processing tube 20B. The inclination angle θ of the raw material processing tube 20B was set to 3 degrees. Further, a thermocouple for monitoring the temperature was disposed in the vicinity of the central portion of the outer peripheral surface of the raw material processing tube 20B. In addition, 20 to 30 pieces of the inhibition member 170 made of glass pieces having an outer diameter of 10 to 20 mm were densely arranged in the stay portion formed by the stay portion forming member 40B. The glass piece was made of the same material as the raw material processing tube 20B.

  As the heating means HT, a plurality of rod-shaped SiC heaters having a length comparable to that of the raw material processing tube 20B and a plurality of them are arranged around the raw material processing tube 20B so as to be substantially parallel to the raw material processing tube 20B. Further, below the outflow port 24, a water tank was disposed in order to rapidly cool the melt flowing out from the outflow port 24 to obtain a crude dissolved product (cullet).

-Preparation of coarsely dissolved material-
The raw material processing tube 20B was heated to around 1100 degrees by a SiC heater. Subsequently, while maintaining the heating temperature of the raw material treatment tube 20B at 1100 degrees, the powdery raw material M was charged from the charging port 22 side. In addition, the raw material M was injected | thrown-in 1 kg at a fixed time interval. Further, the raw material processing tube 20B was rotated by a certain angle every time the raw material M was heated and dissolved with the central axis C as a rotation axis. And in the raw material processing pipe | tube 20B, the raw material M used as the melt was made to flow out from the outflow port 24 side, and rapidly cooled in the water tank, and the cullet was obtained.

-Main melting and production of optical glass-
2 kg of the obtained cullet was put into a platinum crucible and main melting was carried out at about 1240 degrees for 4 hours. The obtained glass was slowly cooled in a slow cooling furnace, the refractive index nd was 1.9236, the Abbe number νd An optical glass of 20.9 was obtained.

(Example 2)
The same structure as the raw material melting furnace 10 used in Example 1 is used except that the raw material processing tube 20D shown in FIG. 5 is used instead of the raw material processing tube 20B shown in FIG. The raw material melting furnace 10 was used. Here, the dimensional shape of the cylindrical tube 30A constituting the raw material processing tube 20D is the same as the cylindrical tube 30A used in the first embodiment. In addition, the staying portion forming member 40D is appropriately arranged so that a ring-shaped member made of the same material as that used for the raw material processing tube is equally divided into four at equal intervals in the circumferential direction and then easily placed in the cylindrical tube 30A. The shape is arranged. In addition, the retention part formation member 40D was arrange | positioned in the position of about 20 cm from the outflow port 24 side of raw material process pipe | tube 20D similarly to Example 1. FIG. The inclination angle θ of the raw material processing tube 20B was set to 3 degrees as in the first embodiment. Further, a thermocouple for monitoring the temperature was disposed in the vicinity of the central portion of the outer peripheral surface of the raw material processing tube 20B.

  Then, except that the raw material melting furnace 10 using the raw material processing tube 20D was used, a crude melt (cullet) was prepared in the same manner as in Example 1, and this was melted to obtain the same refractive index nd as in Example 1. An optical glass having an Abbe number νd was obtained.

(Comparative Example 1)
Rough dissolution was performed under the same conditions as in Example 1 except that a simple cylindrical tube in which the retention portion forming member 40B and the block-like member 50 were removed from the raw material processing tube 20B used in Example 1 was used as the raw material processing tube. It was. And the obtained melt was rapidly cooled in water and the cullet was produced. Furthermore, this cullet was used and this melting was performed under the same conditions as in Example 1 to obtain an optical glass.

(Evaluation)
For the optical glasses obtained in Examples 1 and 2 and Comparative Example 1, transmittance was measured with a spectrophotometer within a range of 300 nm to 700 nm. These optical glasses of Examples 1 and 2 had optical characteristics in which the transmittance decreased from around 500 nm and the transmittance became almost zero at around 400 nm. Here, the wavelength (λ70) at which the transmittance is 70% was determined. The results are shown in Table 1.

  As shown in Table 1, the optical glass of Example 1 is more likely to transmit light at a wider wavelength in the short wavelength range of visible light than the optical glass of Example 2 (it is difficult to color). understood. On the other hand, in the raw material processing tube 20B shown in FIG. 3, the staying portion forming member 40B is disposed in the inner peripheral direction so as to be substantially in close contact with the inner peripheral surface 26, whereas in the raw material processing tube 20D shown in FIG. Gaps G2 and G3 are formed between the inner peripheral surface 26 and the retention portion forming member 40D. From these, the Example 1 using the raw material melting furnace 10 provided with the raw material processing tube 20B in which the raw material M is easily retained in the raw material processing tube 20 for a long period of time is more preferable than the second example. It can be said that it is easier to suppress the coloring of the optical glass. Further, in Comparative Example 1 using a simple cylindrical tube as the raw material processing tube, since the raw material M cannot be retained in the raw material processing tube, it may be more easily colored than in either Example 1 or Example 2. I understood.

(Example 3)
Instead of the raw material processing tube 20B used in the first embodiment, a member (raw material processing rod 210 shown in FIG. 17) obtained by substantially dividing the raw material processing tube 20B into two on a plane including the central axis C is used. Using. Except for the point that the raw material processing tube 210 has a structure in which the raw material processing tube 20B is divided into two, the other dimensions and constituent materials are the same as those of the raw material processing tube 20B. Then, except that the raw material treatment basket 210 was not rotated, the inhibiting member 170 was disposed in the stay portion as in Example 1, and a cullet was produced under the same conditions as in Example 1. As a result, λ70 was almost the same value as in Example 1.

10 Raw Material Melting Furnace 20, 20A, 20B, 20C, 20D, 20E, 20F, 20G, 20H, 20I, 20J, 20K, 20L, 20M Raw Material Processing Tube (Raw Material Processing Member)
22 Input port 24 Outlet port 26 Inner peripheral surface 26D Lowermost surfaces 30, 30A, 30B (inner peripheral surface 26) Cylindrical tubes 40, 40A, 40B, 40C, 40D, 40E, 40F, 40G, 40H In the retention portion forming member 40AI Peripheral surface 40EI Inner peripheral surface 40EO Outer peripheral surface 50 Block-shaped member 60 Cylindrical tube 62 Convex part 70 Cylindrical pipe 72 Concave part 80 Cylindrical body 90
92 End face 100 Second cylindrical tube (tubular member)
102 End face 104 End face 110 Third cylindrical tube (tubular member)
112 end face 120 first step 122 second step 130 cylinder 140 first cylindrical tube (tubular member)
142 Inner peripheral surface 150 Second cylindrical tube (tubular member)
152 Outer peripheral surface 160 Step 170 Inhibiting member 200 Raw material processing trough (raw material processing member)
210 Housing (semi-cylindrical tube)

Claims (22)

In a raw material melting furnace for melting a raw material to produce a glass cullet for optical glass production,
An inlet for supplying the raw material for manufacturing the glass cullet and an outlet for discharging the melted raw material; and the inlet is located above the outlet, A raw material processing member made of a material selected from quartz and alumina and electrocast brick,
Heating means for heating the raw material that moves from the inlet side to the outlet side in the raw material processing member,
A raw material melting furnace characterized in that a retention portion is provided in the raw material processing member for temporarily retaining the raw material that moves while melting in the raw material processing member in the raw material processing member. In the raw material melting furnace according to claim 1,
The raw material processing member comprises a cylindrical raw material processing tube,
The raw material melting furnace, wherein the raw material processing tube is arranged with a central axis inclined with respect to a horizontal direction. In the raw material melting furnace according to claim 2,
The raw material treatment tube has at least a cylindrical body and one or more staying portion forming members,
A raw material melting furnace, wherein one or more staying portion forming members are fixedly disposed on an inner periphery of the cylindrical body. In the raw material melting furnace according to claim 3,
A raw material melting furnace, wherein at least one staying part forming member among the one or more staying part forming members is disposed so as to be substantially in close contact with the inner peripheral surface. In the raw material melting furnace according to claim 4,
The shape of the staying portion forming member disposed so as to be in close contact with the inner peripheral surface is a block shape,
A raw material melting furnace, wherein a plurality of block-like staying portion forming members that are substantially in close contact with the inner peripheral surface are arranged along an inner peripheral direction of the cylindrical body. In the raw material melting furnace according to claim 5,
A raw material melting furnace, wherein a gap is provided between two block-shaped staying portion forming members adjacent to each other in the inner circumferential direction of the cylindrical body. In the raw material melting furnace according to claim 4,
As the staying part forming member that is substantially in close contact with the inner peripheral surface, one annular staying part forming member whose outer peripheral shape substantially coincides with the inner peripheral shape at any position in the central axis direction of the cylindrical body is used. A raw material melting furnace. In the raw material melting furnace according to claim 7,
The annular staying part forming member is provided with at least one flow path selected from a pore penetrating in the axial direction of the staying part forming member and a slit penetrating in the axial direction of the staying part forming member. A raw material melting furnace. In the raw material melting furnace according to claim 4,
As the staying part forming member that is substantially in close contact with the inner peripheral surface, a single plate-like staying part forming member whose outer peripheral shape substantially matches the inner peripheral shape at any position in the central axis direction of the cylindrical body is used. A raw material melting furnace. In the raw material melting furnace according to claim 9,
The plate-like staying part forming member has at least one flow path selected from a pore penetrating in the axial direction of the staying part forming member and a slit penetrating in the axial direction of the staying part forming member. A raw material melting furnace characterized by being provided. In the raw material melting furnace according to any one of claims 7 to 10,
A raw material melting furnace, wherein an inner diameter of the cylindrical body decreases as it goes from the inlet side to the outlet side. In the raw material melting furnace according to any one of claims 2 to 11,
The raw material processing tube has at least a cylindrical body,
A raw material melting furnace, wherein a convex portion that is integrated with the cylindrical body is provided on an inner peripheral surface of the cylindrical body. In the raw material melting furnace according to any one of claims 2 to 12,
The raw material processing tube has at least a cylindrical body,
A raw material melting furnace, wherein a concave portion is provided on an inner peripheral surface of the cylindrical body. In the raw material melting furnace according to any one of claims 2 to 13,
The raw material treatment tube has at least a cylinder having a structure in which two or more cylindrical members are joined in series,
The inner peripheral surface of the cylindrical body is formed by joining one cylindrical member and another cylindrical member, and at least one step that is continuous in the circumferential direction is provided,
The raw material melting furnace characterized in that, at least one of the one or more steps, an inner diameter of the step on the inlet side is larger than an inner diameter of the step on the outlet side. In the raw material melting furnace according to any one of claims 2 to 14,
The raw material treatment tube has at least a cylindrical body and a plurality of inhibiting members,
A raw material melting furnace characterized in that a plurality of inhibiting members are arranged densely on the inner peripheral surface of the cylindrical body. In the raw material melting furnace according to any one of claims 1 to 15,
The retention section is a portion where the water depth of the raw material melted in the raw material processing member is locally deep with respect to the longitudinal direction of the raw material processing member. In the raw material melting furnace according to any one of claims 1 to 16,
The retention portion is a portion where the flow resistance of the raw material is locally increased with respect to the longitudinal direction of the raw material processing member. In the raw material melting furnace according to any one of claims 1 to 17,
A material melting furnace characterized in that all the materials constituting the material processing member are made of quartz glass. In the raw material melting furnace according to any one of claims 1 to 18,
A raw material melting furnace used for producing a glass cullet for producing a phosphate-based optical glass. The glass cullet for optical glass manufacture is manufactured by melt | dissolving a raw material using the raw material melting furnace as described in any one of Claims 1-19, and making it into a melt, and quenching the said melt in water. A method for producing a glass cullet for producing optical glass. 21. A method for producing an optical glass, comprising: producing an optical glass by main melting the glass cullet produced by the method for producing a glass cullet for producing an optical glass according to claim 20. The method for producing an optical glass according to claim 21, wherein the optical glass is a phosphate-based optical glass.

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