Vaporization device and vaporization method

Abstract

To provide a vaporization device capable of vaporizing liquid material efficiently in a large quantity while reducing or preventing gelation of the liquid material.SOLUTION: A vaporization device includes: a tank in which a liquid material used for manufacturing an optical fiber preform is vaporized: an introduction pipe connected to the tank for introducing the liquid material into the tank; a tabular body which is provided inside the tank and to which the liquid material introduced from the introduction pipe is supplied; a first heating unit for heating the tank and the tabular body; and a control unit for controlling the first heating part so as to heat the tank and the tabular body to a boiling point of the material or higher.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] The present invention relates to a vaporization device and a vaporization method. [Background technology]

[0002] Patent Document 1 describes a vaporizer that vaporizes a liquid material by heating a pipe through which a gas-liquid mixture of the liquid material and a carrier gas flows. In the vaporizer described in Patent Document 1, the temperatures at the inlet and outlet of the pipe are controlled by a front-stage heater and a rear-stage heater that heat the front-stage region and the rear-stage region, respectively, of the area in which the pipe is arranged.

[0003] Also, Patent Document 2 describes a method for vaporizing a liquid precursor material for use in vapor deposition, which method includes directing a flow of the liquid precursor material toward a vertical wall of an expansion vessel and heating the vertical wall of the expansion vessel to a temperature sufficient to vaporize a predetermined portion of the flow of the liquid precursor material. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-171341 [Patent Document 2] Special Publication No. 2014-517801 Summary of the Invention [Problem to be solved by the invention]

[0005] However, while the vaporization device described in Patent Document 1 can vaporize a large amount of liquid material, there is a risk that the organic liquid material will gel due to local overheating of the piping, causing damage to the device. On the other hand, in the method described in Patent Document 2, the gel formed from the liquid precursor material is collected in the lower region of the expansion tank, but vaporizing the liquid precursor material only on the wall surface requires a large device and requires a large amount of thermal energy to vaporize the liquid precursor material due to poor vaporization efficiency.

[0006] The present invention has been made in consideration of the above, and aims to provide an evaporation device and an evaporation method that can efficiently evaporate large amounts of liquid material while reducing or preventing gelation of the liquid material. [Means for solving the problem]

[0007] According to one aspect of the present invention, there is provided an evaporation device comprising: a tank in which liquid material used in the manufacture of optical fiber preform is evaporated; an inlet pipe connected to the tank and introducing the liquid material into the tank; a plate-shaped body provided in the tank and supplied with the liquid material introduced from the inlet pipe; a first heating unit that heats the tank and the plate-shaped body; and a control unit that controls the first heating unit to heat the tank and the plate-shaped body to above the boiling point of the material.

[0008] According to another aspect of the present invention, there is provided a vaporization method using the above-mentioned vaporization device, characterized in that the tank and the plate-like body are heated by the first heating section to a temperature above the boiling point of the material, the material is introduced into the interior of the tank through the inlet pipe, and the liquid material is supplied to the plate-like body. [Effects of the Invention]

[0009] According to the present invention, it is possible to efficiently vaporize a large amount of liquid material while reducing or preventing gelation of the liquid material. [Brief explanation of the drawings]

[0010] [Figure 1A] FIG. 1A is a schematic diagram showing a vaporization device according to a first embodiment of the present invention. [Figure 1B] FIG. 1B is a schematic diagram showing a vaporizer according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a flowchart showing the operation of the vaporizer according to the first embodiment of the present invention. [Figure 3A]FIG. 3A is a schematic diagram showing a vaporizer according to a second embodiment of the present invention. [Figure 3B] FIG. 3B is a schematic diagram showing a vaporizer according to a second embodiment of the present invention. [Figure 4] FIG. 4 is a schematic diagram showing a vaporizer according to a third embodiment of the present invention. [Figure 5A] FIG. 5A is a schematic diagram showing a vaporizer according to a fourth embodiment of the present invention. [Figure 5B] FIG. 5B is a schematic diagram showing a vaporizer according to a fourth embodiment of the present invention. [Figure 6A] FIG. 6A is a schematic diagram showing a vaporizer according to a fifth embodiment of the present invention. [Figure 6B] FIG. 6B is a schematic diagram showing a vaporizer according to a fifth embodiment of the present invention. [Figure 7A] FIG. 7A is a schematic diagram showing a vaporizer according to a sixth embodiment of the present invention. [Figure 7B] FIG. 7B is a schematic diagram showing a vaporizer according to a sixth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] [First embodiment] A vaporizer according to a first embodiment of the present invention will be described with reference to Figures 1A to 2. Figures 1A and 1B are schematic diagrams showing the vaporizer according to this embodiment. Figure 2 is a flowchart showing the operation of the vaporizer according to this embodiment.

[0012] First, the configuration of vaporizer 10 according to this embodiment will be described with reference to Figures 1A and 1B. Figure 1A shows the overall configuration of vaporizer 10 and also shows a vertical cross-sectional view of vaporization tank 114. Figure 1B shows a horizontal cross-sectional view of vaporization tank 114.

[0013] The vaporizer 10 according to this embodiment vaporizes a liquid material M used in manufacturing an optical fiber preform and supplies it to a burner in an optical fiber preform manufacturing apparatus. The optical fiber preform manufacturing apparatus is not particularly limited, and may be, for example, a chemical vapor deposition (CVD) method, an outside vapor deposition (OVD) method, a vapor phase axial deposition (VAD) method, or the like, to deposit soot to manufacture an optical fiber preform.

[0014] 1A and 1B, vaporizer 10 according to this embodiment includes raw material tank 102, pressurization pipe 104, introduction pipe 106, flow rate regulator 108, gas pipe 110, and preheater 112. Vaporizer 10 also includes vaporization tank 114, heating plate 116, heater 118, temperature sensor 120, supply pipe 122, and heater 124. Vaporizer 10 also includes control device 126.

[0015] The raw material tank 102 is a storage unit that stores the material M, which is a raw material for manufacturing an optical fiber preform. The material M is a liquid material that is liquid at room temperature. The raw material tank 102 stores the material M in a liquid state. The material M is not particularly limited, but is, for example, a reactive organic material that can be gelled by a polymerization reaction or the like, and specifically, octamethylcyclotetrasiloxane (OMCTS, D4).

[0016] One end of a pressurization pipe 104 is connected to the raw material tank 102. The pressurization pipe 104 is a pipe that supplies pressurized gas, such as nitrogen gas, to the inside of the raw material tank 102. The supply of pressurized gas from the pressurization pipe 104 is controlled by a control device 126.

[0017] One end of an introduction pipe 106 is connected to the raw material tank 102. The other end of the introduction pipe 106 is connected to a vaporization tank 114. The introduction pipe 106 is a pipe that supplies and introduces the liquid material M stored in the raw material tank 102 into the vaporization tank 114. The liquid material M is introduced into the introduction pipe 106 by pressurizing the inside of the raw material tank 102 with pressurized gas from the pressurization pipe 104.

[0018] A gas pipe 110 is connected to the middle portion of the introduction pipe 106. The gas pipe 110 is a pipe that supplies a carrier gas to the introduction pipe 106, which carries the liquid material M to the vaporization tank 114. The gas pipe 110 is connected to the introduction pipe 106 so that the carrier gas supplied to the introduction pipe 106 flows toward the vaporization tank 114 in the introduction pipe 106. The material M is mixed with the carrier gas in the introduction pipe 106 to form a gas-liquid mixture, which is then introduced from the introduction pipe 106 into the vaporization tank 114. The carrier gas is not particularly limited, but is, for example, an inert gas such as argon gas. The supply of the carrier gas from the gas pipe 110 is controlled by a control device 126.

[0019] Further, the inlet pipe 106 is provided with a flow rate regulator 108. The flow rate regulator 108 is an adjusting unit that adjusts the flow rate of the liquid material M flowing through the inlet pipe 106. The adjustment of the flow rate of the material M by the flow rate regulator 108 is controlled by the control device 126.

[0020] Furthermore, a preheater 112 is provided in the inlet pipe 106 between the connecting portion with the gas pipe 110 and the connecting portion with the vaporization tank 114. The preheater 112 is a heating unit that heats the inlet pipe 106 to heat the material M carried by the carrier gas inside the inlet pipe 106 to a temperature close to its vaporization temperature, specifically close to the boiling point of the material M. By heating with the preheater 112, the material M is brought into a state where it is easy to vaporize inside the inlet pipe 106. The heating by the preheater 112 is controlled by a control device 126.

[0021] The vaporization tank 114 is a container having an internal space for vaporizing the material M introduced from the introduction pipe 106. Inside the vaporization tank 114, the liquid material M used in manufacturing the optical fiber preform is vaporized. The vaporization tank 114 has side walls, a bottom plate, and a top plate that define the internal space. The internal space of the vaporization tank 114 is not particularly limited, but has a cylindrical shape such as a square pillar or a cylinder with the vertical direction as the height direction. Furthermore, the vaporization tank 114 is made of a material that can be heated to a temperature above the vaporization temperature of the material M, specifically above the boiling point of the material M.

[0022] The other end of the inlet pipe 106 is connected to a side wall of the vaporization tank 114 so that the material M can be introduced from the inlet pipe 106 into the internal space of the vaporization tank 114. The other end of the inlet pipe 106 is provided with a discharge hole 106a, which is an opening through which the material M is discharged. The other ends of multiple inlet pipes 106 may be connected to the side wall of the vaporization tank 114, for example, at equal intervals in the horizontal direction. In this case, the other ends of each of multiple sets of inlet pipes 106 arranged from the raw material tanks 102 to the inlet pipes 106 may be connected to the side wall of the vaporization tank 114. Alternatively, the multiple inlet pipes 106 may be multiple branch pipes branching from a single inlet pipe 106, each of which has its other end connected to the side wall of the vaporization tank 114. FIGS. 1A and 1B show a case in which the inlet pipes 106 are connected to two opposing side walls of the vaporization tank 114, respectively.

[0023] The other end of introduction pipe 106 is connected to the side wall of vaporization tank 114 so that discharge hole 106a is exposed on the inner surface of the side wall of vaporization tank 114. Note that introduction pipe 106 may be connected to vaporization tank 114 so that the tip portion including the other end protrudes into the internal space of vaporization tank 114. Furthermore, the connection point of introduction pipe 106 to vaporization tank 114 does not necessarily have to be the side wall of vaporization tank 114, and may be another location such as the top plate of vaporization tank 114.

[0024] Two heating plates 116 are provided on the inner surface of the side wall of the vaporization tank 114, located above and below the introduction pipe 106. Liquid material M is supplied to the heating plates 116 from the introduction pipe 106. The heating plates 116 are plate-shaped bodies that are heated by a heater 118 to vaporize the liquid material M supplied from the introduction pipe 106 and brought into proximity with or contact with the heating plates 116. It should be noted that the number of heating plates 116 does not necessarily need to be two; a plurality of heating plates 116 may be installed as in the fourth and fifth embodiments described below, or only one heating plate may be installed below the introduction pipe 106.

[0025] The heating plate 116 has a horizontal surface perpendicular to the vertical direction. The heating plate 116 forms a corrugated structure, which is an uneven structure, on the inner surface of the sidewall of the vaporization tank 114. The surface of the heating plate 116 does not necessarily have to be a horizontal surface perpendicular to the vertical direction, but may be a surface intersecting the vertical direction. The heating plate 116 is made of a material that can be heated to a temperature above the vaporization temperature of the material M, specifically above the boiling point of the material M. The heating plate 116 may be provided integrally with the vaporization tank 114 or may be provided separably from the vaporization tank 114. The size of the surface of the heating plate 116 can be appropriately set depending on the flow rate of the material M to be vaporized, the vaporization rate, etc. The surface of the heating plate 116 may be smooth or may have an uneven surface with unevenness formed to increase the area in contact with the material M.

[0026] The heater 118 is provided relative to the vaporization tank 114 so as to heat the vaporization tank 114 and the heating plate 116 installed therein. The heater 118 is a heating unit that heats the vaporization tank 114 and the heating plate 116 to a temperature equal to or higher than the vaporization temperature of the material M, specifically equal to or higher than the boiling point of the material M. The configuration of the heater 118 is not particularly limited as long as it can heat the vaporization tank 114 and the heating plate 116 to a predetermined temperature. The heater 118 may be provided so as to heat all or part of the vaporization tank 114 from the outside, or may be provided at one or more locations outside or inside the vaporization tank 114. Heating by the heater 118 is controlled by a control device 126.

[0027] One or more temperature sensors 120 are provided inside the vaporization tank 114. The temperature sensors 120 are measurement units that measure the temperature inside the vaporization tank 114, including the temperature of the heating plate 116. The temperature sensors 120 output a temperature signal indicating the measured temperature inside the vaporization tank 114 to the control device 126.

[0028] One end of supply pipe 122 is connected to the top plate of vaporization tank 114. The other end of supply pipe 122 is connected to a burner of an optical fiber manufacturing apparatus (not shown). Supply pipe 122 is a pipe that discharges material M vaporized inside vaporization tank 114 from vaporization tank 114 and supplies it to the burner of the optical fiber manufacturing apparatus, which is the supply destination. Material M vaporized inside vaporization tank 114 is discharged from vaporization tank 114 and introduced into supply pipe 122. Note that the connection point of supply pipe 122 to vaporization tank 114 does not necessarily have to be the top plate of vaporization tank 114, and may be another point, such as the side wall of vaporization tank 114.

[0029] Further, the supply pipe 122 is provided with a heater 124. The heater 124 is a heating unit that heats the supply pipe 122 to heat the vaporized material M flowing inside the supply pipe 122 toward the supply destination to a temperature equal to or higher than the vaporization temperature, specifically, equal to or higher than the boiling point of the material M. Heating by the heater 124 can prevent the material M from liquefying again in the supply pipe 122. Heating by the heater 124 is controlled by a control device 126.

[0030] The control device 126 is a control unit that manages and controls each part of the vaporization device 10 while vaporizing the material M. The control device 126 may be configured by a single control device, or may be configured by multiple control devices installed for each control target.

[0031] Specifically, the control device 126 can control the pressure of the pressurized gas that is introduced from the pressurizing pipe 104 into the raw material tank 102 and pressurizes the inside of the raw material tank 102. The control device 126 can also control the flow rate of the carrier gas that flows through the gas pipe 110. The control device 126 can also control the flow rate regulator 108 to control the flow rate of the material M introduced into the vaporization tank 114, the timing of introduction, etc.

[0032] The control device 126 can also control the preheater 112 to control the temperature at which the introduction pipe 106 is heated to a temperature close to the boiling point but below the boiling point of the material M. The control device 126 can also control the heater 118 based on a temperature signal received from the temperature sensor 120 to control the temperature at which the vaporization tank 114 and the heating plate 116 are heated to a temperature equal to or higher than the boiling point of the material M. The control device 126 can also control the heater 124 to control the temperature at which the supply pipe 122 is heated to a temperature equal to or higher than the boiling point of the material M.

[0033] In this manner, the vaporizer 10 according to this embodiment for vaporizing the material M is configured.

[0034] Next, the method for vaporizing the material M using the vaporization device 10 according to this embodiment will be further described with reference to FIG.

[0035] As shown in FIG. 2, first, the control device 126 heats the respective parts of the vaporizer 10, including the inlet pipe 106, vaporization tank 114, heating plate 116, and supply pipe 122, to predetermined set temperatures (step S102). At this time, the control device 126 controls the preheater 112 to heat the inlet pipe 106 to a temperature close to but lower than the boiling point of the material M. The control device 126 also controls the heater 118 to heat the vaporization tank 114 and heating plate 116 to a temperature equal to or higher than the boiling point of the material M. The control device 126 also controls the heater 124 to heat the supply pipe 122 to a temperature equal to or higher than the boiling point of the material M. When heating the respective parts of the vaporization tank 114, heating plate 116, and supply pipe 122 to a temperature equal to or higher than the boiling point of the material M, the control device 126 heats them to a temperature that prevents deactivation of the material M due to denaturation, combustion, or the like.

[0036] When OMCTS, which has a boiling point of 171 to 175°C, is used as material M, the temperature to which vaporization tank 114 and heating plate 116 are heated is preferably 180°C or lower, since OMCTS may gel if its boiling point is significantly exceeded.

[0037] The control device 126 determines whether or not each of the components, including the inlet pipe 106, the vaporization tank 114, the heating plate 116, and the supply pipe 122, has reached a predetermined set temperature (step S104), and waits until the set temperature is reached (step S104, NO). The control device 126 can determine whether or not each component has reached the set temperature based on the temperatures detected by the temperature sensor 120 installed in the vaporization tank 114 and the temperature sensors (not shown) installed in the inlet pipe 106 and the supply pipe 122.

[0038] Next, when the controller 126 determines that each component has reached the set temperature (step S104, YES), the controller 126 heats the inlet pipe 106, vaporization tank 114, heating plate 116, and supply pipe 122 as described above to maintain each component at the set temperature, and introduces material M from the raw material tank 102 into the vaporization tank 114 through the inlet pipe 106 (step S106). At this time, the controller 126 introduces pressurized gas from the pressurization pipe 104 into the raw material tank 102 to pressurize the inside of the raw material tank 102, and introduces material M from the raw material tank 102 into the inlet pipe 106. The controller 126 also supplies carrier gas from the gas pipe 110 to the inlet pipe 106, and introduces liquid material M into the vaporization tank 114 in the form of a gas-liquid mixture mixed with the carrier gas. Furthermore, the control device 126 controls the flow rate of the material M introduced into the vaporization tank 114 by controlling the flow rate regulator 108 to control the flow rate of the material M flowing through the introduction pipe 106 .

[0039] Inside the vaporization tank 114, material M is discharged from discharge hole 106a of introduction pipe 106 and supplied to heating plate 116. Material M supplied to heating plate 116 is heated by heating plate 116 to a temperature above its boiling point, which is its vaporization temperature, and vaporizes (step S108). When material M supplied to heating plate 116 comes into contact with or is close to heating plate 116 heated to a temperature above the boiling point of material M, material M is heated to a temperature above the boiling point and vaporizes. Material M discharged from discharge hole 106a is vaporized on the upper surface of heating plate 116 located below the direction in which material M falls, and may also be discharged upward and vaporized on the lower surface of the upper heating plate 116.

[0040] Material M that is not vaporized by heating plate 116 falls from heating plate 116 to the bottom of vaporization tank 114. Material M that has fallen to the bottom of vaporization tank 114 is heated to above the boiling point of material M and vaporizes at the bottom of vaporization tank 114, which is heated to above the boiling point of material M. Note that a portion of material M that has not been vaporized and has gelled may remain at the bottom of vaporization tank 114.

[0041] In this embodiment, the heating plate 116 heats the material M over a wide area inside the vaporization tank 114, reducing or preventing gelation of the material M due to localized overheating. Even if gelation occurs and adheres to the inner surface of the vaporization tank 114, the sufficiently large heating area reduces or prevents a decrease in the vaporization rate of the material M. Thus, this embodiment reduces or prevents poor vaporization of the material M, allowing for efficient vaporization of a large amount of the material M. Furthermore, because the material M is heated to a temperature close to its boiling point by the preheater 112 in the inlet pipe 106 before being introduced into the vaporization tank 114, it can be vaporized by the heating plate 116 in a short time. Furthermore, any material M not vaporized by the heating plate 116 is heated and vaporized at the bottom of the vaporization tank 114, allowing for efficient vaporization of the material M. Specifically, when the material M is, for example, OMCTS, this embodiment can vaporize the OMCTS at a rate of 50 g / min or more.

[0042] Material M vaporized in this way inside vaporization tank 114 is discharged from vaporization tank 114 into supply pipe 122 and supplied to a burner of the optical fiber manufacturing apparatus, which is the destination of vaporized material M, through supply pipe 122. Since supply pipe 122 is heated to a temperature equal to or higher than the boiling point of material M, it is possible to prevent material M from liquefying again in supply pipe 122.

[0043] While the vaporized material M is being supplied to the supply destination as described above, the control device 126 determines whether or not to stop the supply of the material M to the supply destination (step S110). The control device 126 can determine whether or not to stop the supply of the material M to the supply destination based on whether a preset time to stop the supply of the material M has arrived, whether or not an instruction signal instructing the stop of the supply of the material M to the supply destination has been input, etc.

[0044] When the control device 126 determines that the supply of the material M to the supply destination will be continued without stopping (step S110, NO), the control device 126 proceeds to step S106 and executes the processing from step S106 onwards to continue the supply of the material M to the supply destination.

[0045] On the other hand, when the control device 126 determines to stop the supply of the material M to the supply destination (step S110, YES), it executes a stop process to stop the supply of the material M to the supply destination (step S112). As the stop process, the control device 126 executes processes such as stopping the pressurization of the raw material tank 102 by the pressurized gas from the pressurization pipe 104, stopping the supply of the carrier gas from the gas pipe 110, and stopping heating by the preheater 112, the heating heater 118, and the heating heater 124. In this way, the vaporization of the material in the vaporization tank 114 is stopped, and the supply of the material M to the supply destination is stopped.

[0046] As described above, according to this embodiment, it is possible to efficiently vaporize a large amount of the liquid material M while reducing or preventing gelation of the liquid material M.

[0047] [Second embodiment] A vaporizer according to a second embodiment of the present invention will be described with reference to Figures 3A and 3B. Figures 3A and 3B are schematic diagrams showing the vaporizer according to this embodiment. Note that components similar to those in the vaporizer according to the first embodiment are given the same reference numerals, and descriptions thereof will be omitted or simplified.

[0048] The basic configuration of the vaporizer according to this embodiment is substantially the same as that of the vaporizer 10 according to the first embodiment. The vaporizer according to this embodiment differs from the vaporizer 10 according to the first embodiment in the discharge holes provided in the inlet pipe 106. The vaporizer according to this embodiment will be described below with reference to FIGS. 3A and 3B. FIG. 3A shows a vertical cross-sectional view of the vaporizer tank 114 in the vaporizer according to this embodiment. FIG. 3B shows a horizontal cross-sectional view of the vaporizer tank 114 in the vaporizer according to this embodiment.

[0049] 3A and 3B, in this embodiment, the introduction pipe 106 is connected to the vaporization tank 114 so that the tip, including the other end, protrudes horizontally into the space inside the vaporization tank 114. The introduction pipe 106 protrudes so that the other end is aligned with the edge of the heating plate 116 in the protruding direction. Note that the introduction pipe 106 may protrude so that the other end is located closer to the sidewall of the vaporization tank 114 than the edge of the heating plate 116 in the protruding direction.

[0050] A plurality of discharge holes 106b are provided in place of or in addition to discharge holes 106a at the tip of lead-in pipe 106 that protrudes into the internal space of vaporization tank 114. The plurality of discharge holes 106b are provided at equal intervals along the axial direction of lead-in pipe 106 in the lower and upper portions of the peripheral wall of lead-in pipe 106 at the tip. It is sufficient that the plurality of discharge holes 106b are provided in at least one of the lower, upper, and lateral portions of the peripheral wall of lead-in pipe 106 at the tip. The plurality of discharge holes 106b may also be provided at equal intervals in the axial and circumferential directions of lead-in pipe 106 along the peripheral wall of lead-in pipe 106 at the tip.

[0051] In this embodiment, the material M is emitted from the plurality of emission holes 106b and vaporized by the heating plate 116, so that the liquid material M can be vaporized in large quantities more efficiently.

[0052] [Third embodiment] A vaporizer according to a third embodiment of the present invention will be described with reference to Fig. 4. Fig. 4 is a schematic diagram showing the vaporizer according to this embodiment. Note that components similar to those in the vaporizers according to the first and second embodiments are given the same reference numerals, and descriptions thereof will be omitted or simplified.

[0053] The basic configuration of the vaporizer according to this embodiment is substantially the same as that of the vaporizer according to the second embodiment. The vaporizer according to this embodiment differs from the vaporizer according to the second embodiment in the positional relationship between the tip of the inlet pipe 106, where the plurality of discharge holes 106b are provided, and the heating plate 116. The vaporizer according to this embodiment will be described below with reference to Figure 4. Figure 4 shows a vertical cross-sectional view of the vaporizer tank 114 in the vaporizer according to this embodiment.

[0054] 4, in this embodiment, the lower portion of the tip of the introduction pipe 106 that protrudes into the internal space of the vaporization tank 114 is in contact with the upper surface of the heating plate 116 that is located below the introduction pipe 106. Similar to the second embodiment, the lower portion of the tip of the introduction pipe 106 is provided with a plurality of discharge holes 106b. Note that the space between the introduction pipe 106 and the heating plate 116 that are in contact with each other is not completely sealed, and a gap exists through which the liquid or gaseous material M can move.

[0055] In this embodiment, when material M is discharged from a plurality of discharge holes 106b provided in the lower portion of the tip of introduction pipe 106 that contacts heating plate 116, material M immediately spreads into the gap between introduction pipe 106 and heating plate 116, which are in contact with each other, and comes into contact with heating plate 116. As a result, in this embodiment, material M can be immediately heated and vaporized by heating plate 116, and therefore liquid material M can be vaporized more efficiently in large quantities.

[0056] [Fourth embodiment] A vaporizer according to a fourth embodiment of the present invention will be described with reference to Figures 5A and 5B. Figures 5A and 5B are schematic diagrams showing the vaporizer according to this embodiment. Note that components similar to those in the vaporizers according to the first to third embodiments are given the same reference numerals, and descriptions thereof will be omitted or simplified.

[0057] The basic configuration of the vaporizer according to this embodiment is substantially the same as that of the vaporizer according to the second embodiment. The vaporizer according to this embodiment differs from the vaporizer according to the second embodiment in that a plurality of heating plates 116 are provided below the tip of the inlet pipe 106 that protrudes into the vaporizer tank 114. The vaporizer according to this embodiment will be described below with reference to Figures 5A and 5B. Figure 5A shows a vertical cross-sectional view of the vaporizer tank 114 in the vaporizer according to this embodiment. Figure 5B shows a horizontal cross-sectional view of the vaporizer tank 114 in the vaporizer according to this embodiment.

[0058] In this embodiment, as shown in Figures 5A and 5B, a plurality of heating plates 116A are provided as heating plates 116, aligned in the vertical direction, below the tip of introduction pipe 106 that protrudes into vaporization tank 114. The plurality of heating plates 116A are provided, for example, horizontally, so that their plate surfaces are parallel to one another. Note that although Figures 5A and 5B show a case in which three heating plates 116A are provided, the number of heating plates 116A is not limited to three, and may be two or more.

[0059] The plurality of heating plates 116A have a plate surface with a larger area as the heating plate 116A is positioned lower. The plurality of heating plates 116A are arranged such that the upper heating plate 116A is positioned inside the lower heating plate 116A in a plan view seen from the vertical direction.

[0060] In this embodiment, multiple heating plates 116A are provided below the tip of the introduction pipe 106, so that material M that is not vaporized by the upper heating plates 116A and falls to the lower side can be vaporized by the lower heating plates 116A. As a result, in this embodiment, material M can be reliably heated and vaporized by the multiple heating plates 116A, so that liquid material M can be vaporized more efficiently in large quantities.

[0061] In the above, a case where a plurality of heating plates 116A are provided in the configuration of the vaporizer according to the second embodiment has been described, but a plurality of heating plates 116A may also be provided in the configuration of the vaporizer according to the first or third embodiment.

[0062] [Fifth embodiment] A vaporizer according to a fifth embodiment of the present invention will be described with reference to Figures 6A and 6B. Figures 6A and 6B are schematic diagrams showing the vaporizer according to this embodiment. Note that components similar to those in the vaporizers according to the first to fourth embodiments are given the same reference numerals, and descriptions thereof will be omitted or simplified.

[0063] The basic configuration of the vaporizer according to this embodiment is substantially the same as that of the vaporizer according to the fourth embodiment. The vaporizer according to this embodiment differs from the vaporizer according to the fourth embodiment in that a discharge section 128 for discharging material M is provided at the tip of introduction pipe 106 that protrudes into vaporization tank 114. The vaporizer according to this embodiment will be described below with reference to FIGS. 6A and 6B. FIG. 6A shows a vertical cross-sectional view of vaporization tank 114 in the vaporizer according to this embodiment. FIG. 6B shows a horizontal cross-sectional view of vaporization tank 114 in the vaporizer according to this embodiment.

[0064] 6A and 6B, in this embodiment, a discharge portion 128 for discharging material M is provided at the tip of introduction pipe 106 that protrudes into vaporization tank 114. Discharge portion 128 has a hollow plate shape connected to introduction pipe 106. Discharge portion 128 is provided so as to be parallel to the plate surfaces of heating plates 116, 116A. Discharge portion 128 may also be provided so as to be inclined with respect to the plate surfaces of heating plates 116, 116A.

[0065] The discharge portion 128 is connected to the inlet pipe 106 so that the material M is supplied to the hollow portion of the discharge portion 128 from the inlet pipe 106. The discharge portion 128 may be formed integrally with the inlet pipe 106, or may be provided separably from the inlet pipe 106.

[0066] Furthermore, a plurality of emission holes 128a are provided in emission section 128. The plurality of emission holes 128a are provided at equal intervals, for example in a grid pattern, in the lower surface portion and upper surface portion of emission section 128. Note that emission holes 128a may be provided in at least one of the lower surface portion, upper surface portion, and side surface portion of emission section 128.

[0067] In this embodiment, the material M is emitted in a wide area from the multiple emission holes 128a and vaporized by the heating plates 116, 116A, so that the liquid material M can be vaporized in large quantities more efficiently.

[0068] In this embodiment, the discharge part 128 may be brought into contact with the heating plate 116A in the same manner as the tip of the introduction pipe 106 in the third embodiment.

[0069] Also in this embodiment, two heating plates 116 may be provided, as in the first embodiment.

[0070] [Sixth embodiment] A vaporizer according to a fifth embodiment of the present invention will be described with reference to Figures 7A and 7B. Figures 7A and 7B are schematic diagrams showing the vaporizer according to this embodiment. Note that components similar to those in the vaporizers according to the first to fifth embodiments are given the same reference numerals, and descriptions thereof will be omitted or simplified.

[0071] The basic configuration of the vaporizer according to this embodiment is substantially the same as that of the vaporizer according to the second embodiment. The vaporizer according to this embodiment differs from the vaporizer according to the second embodiment in that the vaporizer 114 is configured to be separable. The vaporizer according to this embodiment will be described below with reference to Figures 7A and 7B. Figure 7A shows a vertical cross-sectional view of the vaporizer 114 before division in the vaporizer according to this embodiment. Figure 7B shows a vertical cross-sectional view of the vaporizer 114 after division in the vaporizer according to this embodiment.

[0072] 7A and 7B, the vaporization tank 114 is composed of a main body 114a and a bottom 114b that can be separated from each other. The vaporization tank 114 can be divided into the main body 114a and the bottom 114b, for example, during maintenance. The vaporization tank 114 can be divided at an appropriate time, such as after the material M has been vaporized.

[0073] Since the vaporization tank 114 has a structure that allows the bottom 114b to be separated in this manner, the gelled material M remaining on the bottom 114b after the material M is vaporized can be easily recovered, and cleaning of the inside of the vaporization tank 114 can be easily performed.

[0074] In the above description, the vaporization tank 114 in the vaporization device according to the second embodiment is configured with a main body 114a and a bottom 114b that can be separated from each other, but this is not limiting. In any of the vaporization devices according to the first, third, or fifth embodiments, the vaporization tank 114 can be configured with a main body 114a and a bottom 114b that can be separated from each other, as in this embodiment.

[0075] [Modified embodiment] The present invention is not limited to the above-described embodiment, and various modifications are possible.

[0076] For example, in the above embodiment, the liquid material M used in manufacturing an optical fiber preform for an optical fiber is vaporized, but the present invention is not limited to this. The vaporizer according to the present invention can be widely applied to vaporizing liquid materials.

[0077] In the above embodiment, an example has been described in which the heater 118 is provided for the vaporization tank 114, but in addition to or instead of the heater 118, a heater may be built into the heating plate 116. In this case, the control device 126 controls the heater built into the heating plate 116 to heat the vaporization tank 114 and the heating plate 116 to a temperature equal to or higher than the boiling point of the material M. The heater may be built into some or all of the multiple heating plates 116. [Explanation of symbols]

[0078] 10...Vaporizer 102...raw material tank 104...Pressure pipe 106...Introduction pipe 106a…Discharge hole 106b…Discharge hole 108...Flow rate regulator 110...Gas pipe 112...Preheater 114...Evaporation tank 114a…Main body part 114b…bottom 116...Heating plate 116A…Heating plate 118...Heater 120...Temperature sensor 122…Supply pipe 124...Heater 126...Control device 128...Emission part 128a…Discharge hole

Claims

1. a tank in which a liquid material used in manufacturing an optical fiber preform is vaporized; an introduction pipe connected to the tank for introducing the liquid material into the interior of the tank; a plate-like body provided inside the tank and supplied with the liquid material introduced through the introduction pipe; a first heating unit that heats the tank and the plate-like body; a control unit that controls the first heating unit so as to heat the tank and the plate-like body to a temperature equal to or higher than the boiling point of the material; and A plurality of the plate-like bodies are provided, the plurality of plate-like bodies are arranged vertically below the introduction pipe, The plate-like body located further downward has a plate surface with a larger area. A vaporization device characterized by:

2. a second heating unit that heats the introduction pipe; The control unit controls the second heating unit to heat the inlet pipe to a temperature below the boiling point of the material.

2. The vaporizer according to claim 1.

3. a tip end of the introduction pipe protruding into the interior of the tank; A plurality of discharge holes for discharging the material are provided at the tip of the introduction pipe along the axial direction of the introduction pipe.

3. The vaporizer according to claim 1 or 2.

4. a tip end of the introduction pipe protruding into the interior of the tank; The supply pipe further includes a hollow plate-shaped discharge part provided at the tip end thereof and having a plurality of discharge holes through which the material is discharged.

3. The vaporizer according to claim 1 or 2.

5. The tip of the introduction pipe is in contact with the plate-like body.

5. The vaporizer according to claim 3 or 4.

6. The plurality of plate-like bodies are arranged such that the upper plate-like body is located inside the lower plate-like body in a plan view seen from the vertical direction.

6. The vaporizer according to claim 1, wherein the vaporizer is a gasoline-based vaporizer.

7. a supply pipe connected to the tank for supplying the material vaporized in the tank to a destination; 7. The vaporizer according to claim 1, wherein the vaporizer is a gasoline-based vaporizer.

8. a third heating unit that heats the supply pipe; The control unit controls the third heating unit to heat the introduction pipe to a boiling point of the material or higher.

8. The vaporizer according to claim 7.

9. The tank has a structure in which the bottom can be separated.

9. The vaporizer according to claim 1, wherein the vaporizer is a gasoline-based vaporizer.

10. A vaporization method using the vaporization device according to any one of claims 1 to 9, The material is introduced into the interior of the tank through the introduction pipe while the tank and the plate-like body are heated by the first heating unit to a boiling point or higher of the material, and the liquid material is supplied to the plate-like body. A vaporization method characterized by:

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