Measurement method for volume flow rate of superheated steam, measurement device for volume flow rate of superheated steam, and heat treatment apparatus

Abstract

To provide a measurement method and a measurement device for a volume flow rate of superheated steam that can measure and monitor the volume flow rate of superheated steam continuously supplied to the supply destination of superheated steam.SOLUTION: Saturated steam or superheated steam is introduced into a first pipe 25. The saturated steam or superheated steam introduced into the first pipe 25 and passing through the first pipe 25 is adjusted to a predetermined temperature and a predetermined pressure to produce superheated steam adjusted to the predetermined temperature and predetermined pressure. The superheated steam adjusted to the predetermined temperature and predetermined pressure is supplied to an area flow meter 27 connected to the first pipe 25, and the area flow meter 27 measures the volume flow rate of the superheated steam passing through the area flow meter 27. The superheated steam that has passed through the area flow meter 27 is introduced into a second pipe 28, and the superheated steam is supplied to a supply destination through the second pipe 28.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a method for measuring a volumetric flow rate of superheated steam, a device for measuring a volumetric flow rate of superheated steam, and a heat treatment apparatus equipped with a device for measuring a volumetric flow rate of superheated steam. [Background technology]

[0002] It is known that a workpiece is heated with superheated steam to perform heat treatment on the workpiece (see, for example, Patent Document 1). Patent Document 1 discloses a steam reflow device 1 that performs heat treatment on the workpiece carried into a heating furnace 2 by heating the workpiece with superheated steam that is continuously supplied into the heating furnace 2. Only the temperature of the superheated steam that is continuously supplied to the heating furnace 2 is measured by a temperature sensor 4.

[0003] When heat treating a workpiece with superheated steam, depending on the type of heat treatment, it may be necessary to more accurately grasp the state of the atmosphere in the heat treatment chamber where the workpiece is heat treated. In this case, it is desirable to be able to measure and monitor the volumetric flow rate of the superheated steam continuously supplied into the heat treatment chamber. However, in the steam reflow device 1 disclosed in Patent Document 1, only the temperature of the superheated steam supplied to the heating furnace 2 can be monitored, and the volumetric flow rate of the superheated steam cannot be measured and monitored.

[0004] A method for measuring the amount of water vapor is disclosed in Patent Document 2. In the method disclosed in Patent Document 2, a gas having a known amount of water vapor is mixed with a high-temperature gas to be measured, the amount of water vapor in the mixed gas is made sufficiently smaller than that of the gas to be measured, the temperature of the mixed gas is lowered to a temperature at which the humidity can be measured with a hygrometer such as a wet-and-dry bulb hygrometer or an electric resistance hygrometer, and the amount of water vapor in the mixed gas is obtained based on the measurement result of the hygrometer. Then, the mixture ratio of the gas to be measured and the gas having the known amount of water vapor is obtained, and the amount of water vapor in the gas to be measured is obtained based on the obtained mixture ratio and the measured amount of water vapor in the mixed gas. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2015-2325 A [Patent Document 2] Japanese Patent Publication No. 53-93089 Summary of the Invention [Problem to be solved by the invention]

[0006] In the steam reflow apparatus 1 disclosed in Patent Document 1, only the temperature of the superheated steam supplied to the heating furnace 2, which is the supply destination of the superheated steam, can be monitored, and the volumetric flow rate of the superheated steam cannot be measured and monitored. In addition, in the measurement method disclosed in Patent Document 2, the gas to be measured is mixed with a gas with a known amount of water vapor to lower the temperature, and then the amount of water vapor in the mixed gas is obtained using a hygrometer, and the amount of water vapor in the gas to be measured is measured based on this and the mixture ratio of the mixed gas. For this reason, it is not possible to measure and monitor the volumetric flow rate of the superheated steam continuously supplied to the supply destination of the superheated steam.

[0007] The present invention aims to provide a method for measuring the volumetric flow rate of superheated steam, which can measure and monitor the volumetric flow rate of superheated steam continuously supplied to a destination of the superheated steam, a device for measuring the volumetric flow rate of superheated steam, and a heat treatment device equipped with the measuring device. [Means for solving the problem]

[0008] (1) In order to solve the above problems, the method for measuring the volumetric flow rate of superheated steam of the present invention includes a steam introduction step of introducing saturated steam or superheated steam into a first pipe, a superheated steam adjustment step of adjusting the saturated steam or superheated steam introduced into and passing through the first pipe to a predetermined temperature and a predetermined pressure to obtain superheated steam adjusted to the predetermined temperature and pressure, a measurement step of supplying the superheated steam adjusted to the predetermined temperature and pressure to an area flow meter connected to the first pipe and measuring the volumetric flow rate of the superheated steam passing through the area flow meter with the area flow meter, and a supply step of introducing the superheated steam that has passed through the area flow meter into a second pipe and supplying the superheated steam to a destination of the superheated steam through the second pipe.

[0009] (2) In the above measurement method, the second pipe is provided with a pressure regulating valve that adjusts the superheated steam supplied to the area flow meter through the first pipe so as to maintain the pressure at the predetermined pressure, and in the superheated steam adjustment process, the superheated steam supplied to the area flow meter through the first pipe is adjusted to the predetermined pressure by the pressure regulating valve.

[0010] (3) In the measurement method, the superheated steam adjustment step heats the first piping with a heater provided in the first piping, thereby heating the saturated steam or superheated steam passing through the first piping to the predetermined temperature, thereby producing superheated steam adjusted to the predetermined temperature.

[0011] (4) In order to solve the above problems, the superheated steam volumetric flow rate measuring device of the present invention comprises a first pipe into which saturated steam or superheated steam is introduced, a superheated steam adjustment unit that adjusts the saturated steam or superheated steam introduced into and passing through the first pipe to a predetermined temperature and a predetermined pressure, thereby producing superheated steam adjusted to the predetermined temperature and pressure, an area flow meter connected to the first pipe, to which the superheated steam adjusted to the predetermined temperature and pressure is supplied and which measures the volumetric flow rate of the superheated steam passing through, and a second pipe into which the superheated steam that has passed through the area flow meter is introduced and which supplies the superheated steam to a destination of the superheated steam.

[0012] (5) In the measuring device, the superheated steam adjustment unit has a pressure regulating valve provided in the second piping that adjusts the superheated steam supplied to the area flow meter through the first piping so as to maintain the pressure at the predetermined pressure, and the superheated steam adjustment unit adjusts the superheated steam supplied to the area flow meter through the first piping to the predetermined pressure by the pressure regulating valve.

[0013] (6) In the measuring device, the superheated steam adjustment unit has a heater provided in the first piping, and by heating the first piping with the heater, saturated steam or superheated steam passing through the first piping is heated to the predetermined temperature, thereby producing superheated steam adjusted to the predetermined temperature.

[0014] (7) In order to solve the above problems, the heat treatment device of the present invention is a heat treatment device that heats a workpiece with superheated steam to perform heat treatment of the workpiece, and includes a heat treatment chamber in which the heat treatment of the workpiece is performed, and a device for measuring the volumetric flow rate of the superheated steam, and the superheated steam supplied through the second piping is introduced into the heat treatment chamber. Effect of the Invention

[0015] According to the present invention, the volumetric flow rate of superheated steam continuously delivered to a destination of the superheated steam can be measured and monitored. [Brief description of the drawings]

[0016] [Figure 1] 1 is a diagram illustrating a heat treatment apparatus according to an embodiment of the present invention. [Diagram 2] 2 is a schematic cross-sectional view of a part of the heat treatment apparatus, showing a state seen from the position of the arrow AA in FIG. 1. [Diagram 3] 2 is a schematic cross-sectional view of a part of the heat treatment apparatus, showing a state seen from the position of the arrow BB in FIG. 1. [Figure 4] FIG. 1 is a diagram showing a device for measuring the volumetric flow rate of superheated steam according to an embodiment of the present invention. [Diagram 5] FIG. 2 is a diagram showing a schematic diagram of a first pipe and a heater in a measuring device for a volumetric flow rate of superheated steam. [Figure 6] FIG. 6A is a cross-sectional view showing a schematic view of a main part of an area flow meter, and FIG. 6B is a cross-sectional view taken along the line CC in FIG. 6A. [Figure 7] 4 is a flowchart for explaining a method for measuring a volumetric flow rate of superheated steam according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The present invention can be widely applied to various uses as a method for measuring the volumetric flow rate of superheated steam, a device for measuring the volumetric flow rate of superheated steam, and a heat treatment device equipped with a device for measuring the volumetric flow rate of superheated steam. In the following description, first, a heat treatment device and a device for measuring the volumetric flow rate of superheated steam according to an embodiment of the present invention will be described, and then a method for measuring the volumetric flow rate of superheated steam according to an embodiment of the present invention will be described.

[0018] [Heat treatment equipment] FIG. 1 is a schematic diagram showing a heat treatment apparatus 1 according to an embodiment of the present invention. The heat treatment apparatus 1 is configured as an apparatus for performing heat treatment on a ceramic or metal workpiece 100 by heating the workpiece 100 with superheated steam. Examples of the ceramic workpiece 100 include ceramic electronic components such as multilayer ceramic capacitors. Note that superheated steam is steam heated to a temperature higher than the boiling point, and is dry steam at a temperature higher than the boiling point. The heat treatment apparatus 1 includes a heat treatment chamber 11 having an inlet 18 through which the workpiece 100 is carried in and an outlet 19 through which the workpiece 100 is carried out. In the heat treatment apparatus 1, the workpiece 100 is heated with superheated steam while being transported from the inlet 18 to the outlet 19 in the heat treatment chamber 11, and the workpiece 100 is heat-treated. Examples of heat treatments performed on the workpiece 100 using superheated steam in the heat treatment apparatus 1 include degreasing and sintering.

[0019] When degreasing is performed in the heat treatment device 1, the workpiece 100 that has been subjected to machining or the like in a processing step prior to the processing in the heat treatment device 1 is carried into the heat treatment device 1. Then, in the heat treatment device 1, the oil and fat attached to the workpiece 100 is heated by superheated steam and vaporized, and removed from the workpiece 100. When sintering is performed in the heat treatment device 1, the workpiece 100 configured as a sintered material bound by a binder containing an oil and fat component is carried into the heat treatment device 1. Then, in the heat treatment device 1, the workpiece 100 is heated by superheated steam, and the binder is vaporized and removed, and then the workpiece 100 from which the binder has been removed is sintered by further heating by superheated steam.

[0020] In the heat treatment apparatus 1, the object 100 to be treated is carried into the heat treatment chamber 11 and is heated by superheated steam while being transported within the heat treatment chamber 11. This performs heat treatment on the object 100 to be treated. After the heat treatment within the heat treatment chamber 11 is completed, the object 100 to be treated is carried out from the heat treatment chamber 11. The object 100 to be treated is continuously transported to the heat treatment chamber 11, subjected to heat treatment while being continuously transported within the heat treatment chamber 11, and continuously carried out from the heat treatment chamber 11.

[0021] When the workpiece 100 is carried into the heat treatment chamber 11, it is carried in a state in which it is arranged in a case 100a formed in a thin box shape, for example. In the case 100a, a plurality of workpieces 100 are stored in a state in which they are arranged at substantially equal intervals. Then, the workpieces 100 are carried into the heat treatment chamber 11 in a state in which they are arranged in the case 100a. In addition, the case 100a storing the plurality of workpieces 100 is provided with, for example, a number of holes formed on the peripheral side and bottom surface and an opening formed on the top surface so that the surrounding gas can pass through with almost no resistance. As a result, the superheated steam in the atmosphere in the heat treatment chamber 11 is configured to flow through the case 100a. In addition, the case 100a may have a structure that allows the superheated steam in the atmosphere in the heat treatment chamber 11 to flow through the case 100a with almost no resistance, and may be formed of, for example, a mesh-like member.

[0022] The heat treatment device 1 is configured to include a heat treatment chamber 11, a heating mechanism 12, a water vapor supply section 13, a water vapor generator 14, a water vapor exhaust section 15, a gas supply section 16, a gas curtain section 17, a device 10 for measuring the volumetric flow rate of superheated steam, and the like.

[0023] The heat treatment chamber 11 has a tunnel-like external shape that extends linearly in a cylindrical shape, and constitutes a chamber in which the workpiece 100 is transported and heat-treated. The interior of the heat treatment chamber 11 is a treatment space in which the workpiece 100 is heat-treated. The transport direction of the workpiece 100, i.e., the direction in which the workpiece 100 is transported inside the heat treatment chamber 11, is parallel to the longitudinal direction of the cylindrical extension of the heat treatment chamber 11. In FIG. 1, the transport direction of the workpiece 100 is indicated by a dashed arrow X1, and will be referred to as the transport direction X1 hereinafter.

[0024] FIG. 2 is a schematic cross-sectional view of a part of the heat treatment apparatus 1, and shows a state seen from the position of the arrow AA in FIG. 1. FIG. 3 is a schematic cross-sectional view of a part of the heat treatment apparatus 1, and shows a state seen from the position of the arrow BB in FIG. 1. With reference to FIGS. 1 to 3, the heat treatment chamber 11 has a pair of side walls (11a, 11b), a ceiling wall 11c, and a bottom wall 11d. The pair of side walls (11a, 11b), the ceiling wall 11c, and the bottom wall 11d of the heat treatment chamber 11 are formed of plate-like members made of steel. The heat treatment chamber 11 is configured to easily conduct heat from a heating mechanism 12 (described later) that heats the heat treatment chamber 11 from the outside. The pair of side walls (11a, 11b) are arranged in parallel, and each is provided as a wall portion extending along the vertical direction and the transport direction X1. The ceiling wall 11c is provided as a wall that defines the upper ceiling portion of the heat treatment chamber 11, and is provided to integrally connect the upper ends of the pair of side walls (11a, 11b). The ceiling wall 11c is formed to extend in an arch shape in a cross section perpendicular to the transport direction X1. The bottom wall 11d is provided as a wall that defines the bottom portion of the heat treatment chamber 11, and is provided to integrally connect the lower ends of the pair of side walls (11a, 11b).

[0025] The entrance 18 of the heat treatment chamber 11 is provided as an opening through which the workpiece 100 in the heat treatment chamber 11 is carried in. The entrance 18 is provided as an opening at one end of the heat treatment chamber 11 in a direction parallel to the transport direction X1, and opens at the upstream end of the heat treatment chamber 11 in the transport direction X1. The entrance 18 is open to the outside of the heat treatment chamber 11, does not have a door, and is always open to the outside. The workpiece 100 is carried into the heat treatment chamber 11 from the entrance 18 while being stored in a case 100a.

[0026] The outlet 19 of the heat treatment chamber 11 is provided as an opening through which the workpiece 100 in the heat treatment chamber 11 is carried out. The outlet 19 is provided as an opening at the end of the heat treatment chamber 11 opposite the end on the inlet 18 side in a direction parallel to the transport direction X1, and opens at the end of the heat treatment chamber 11 downstream of the transport direction X1. The outlet 19 is open to the outside of the heat treatment chamber 11, does not have a door, and is always open to the outside. The workpiece 100 is carried out from the outlet 19 to the outside of the heat treatment chamber 11 while being stored in the case 100a.

[0027] In the heat treatment chamber 11, the workpiece 100 is heated by superheated steam supplied from the steam supply unit 13 described later, and is also heated by the atmosphere in the heat treatment chamber 11 heated through the heat treatment chamber 11 by the heating mechanism 12 described later which heats the heat treatment chamber 11 from the outside. In the heat treatment chamber 11, the workpiece 100 is heated by the heat from the heating mechanism 12 in the conveying direction X1 in a region in which the heating mechanism 12 is arranged. The workpiece 100 is heated by the superheated steam in a region in the heat treatment chamber 11 where the atmosphere contains the superheated steam. In this embodiment, the region in the heat treatment chamber 11 where the workpiece 100 is heated by the superheated steam is the region from the steam supply unit 13 to the inlet side steam exhaust unit 15a in the steam exhaust unit 15 described later, and the region from the steam supply unit 13 to the outlet side steam exhaust unit 15b in the steam exhaust unit 15 described later.

[0028] The heat treatment chamber 11 is also provided with a transport mechanism 20. The transport mechanism 20 is provided as a mechanism for transporting the workpiece 100 in the heat treatment chamber 11. In this embodiment, the transport mechanism 20 is configured to transport the workpiece 100 together with the case 100a, that is, to transport the workpiece 100 in a state where it is stored in the case 100a. The transport mechanism 20 is disposed in a lower region in the heat treatment chamber 11, and is disposed above the bottom wall 11d and parallel to the wall surface of the bottom wall 11d along the transport direction X1. The transport mechanism 20 is configured as a mechanism for transporting the workpiece 100 by, for example, a rotating endless mesh belt 21. The transport mechanism 20 is configured to transport the workpiece 100 stored in the case 100a arranged on the upper surface of the mesh belt 21 together with the case 100a by rotating the mesh belt 21.

[0029] The endless mesh belt 21 has a structure in which roller chains are provided on both edges in the width direction, and is configured to rotate by being driven by a plurality of drive shafts 22 provided with sprockets that mesh with the roller chains. The plurality of drive shafts 22 are installed so as to rotate around their respective axes while being inserted inside the mesh belt 21. The plurality of drive shafts 22 are arranged to extend parallel to each other and extend along a direction perpendicular to the pair of side walls (11a, 11b). Each drive shaft 22 is supported rotatably by the pair of side walls (11a, 11b). Each drive shaft 22 is provided with a pair of sprockets (22a, 22a) spaced apart in the axial direction, and each sprocket 22a meshes with each roller chain on both edges of the mesh belt 21. At least one of the plurality of drive shafts 22 is configured to be rotated by an electric motor (not shown). When the drive shaft 22 is rotated by the electric motor, the rotational drive of the drive shaft 22 is transmitted to the mesh belt 21 via the meshing of the sprocket 22a and the roller chain. Then, the mesh belt 21, which is supported so as to be freely rotatable by the multiple drive shafts 22, rotates. When the mesh belt 21 rotates, the object 100 to be processed, which is placed on the upper surface of the mesh belt 21 while being stored in the case 100a, is transported.

[0030] Referring to FIG. 1, the heating mechanism 12 is provided as a mechanism for heating the heat treatment chamber 11 from the outside, and a plurality of heating mechanisms 12 are provided. The plurality of heating mechanisms 12 are arranged in series along the longitudinal direction of the heat treatment chamber 11 (i.e., along the transport direction X1). In addition, in FIG. 2 and FIG. 3, the heating mechanisms 12 are omitted from illustration. Each heating mechanism 12 is configured to include a heating element (not shown) arranged around the heat treatment chamber 11, and a heat insulating member (not shown) arranged outside the heating element arranged around the heat treatment chamber 11 so as to cover the heating element and the periphery of the heat treatment chamber 11. The heating element is arranged to heat a pair of side walls (11a, 11b), a ceiling wall 11c, and a bottom wall 11d of the heat treatment chamber 11 from the outside. The heating element is configured to include, for example, an electric heating element that converts electric energy supplied from a power source (not shown) into thermal energy, and to generate heat when electricity is applied to the electric heating element. When the heating element of the heating mechanism 12 is activated to generate heat, the pair of side walls (11a, 11b), the ceiling wall 11c, and the bottom wall 11d of the heat treatment chamber 11 are heated by the heat from the heating element of the heating mechanism 12. This heats the atmosphere in the heat treatment chamber 11. The workpiece 100 transported in the heat treatment chamber 11 is heated by the superheated steam, and is also heated by the atmosphere in the heat treatment chamber 11 that has been heated by the heat from the heating mechanism 12.

[0031] 1 and 2, the water vapor supply unit 13 is provided in the heat treatment chamber 11 as a mechanism for supplying superheated water vapor into the heat treatment chamber 11. In the heat treatment apparatus 1 illustrated in this embodiment, the water vapor supply unit 13 is provided in a substantially central portion of the heat treatment chamber 11 in the transport direction X1 of the workpiece 100. Note that the water vapor supply unit 13 may be provided in the heat treatment chamber 11 on the inlet 18 side or the outlet 19 side of the central portion in the transport direction X1.

[0032] The water vapor supply unit 13 includes a nozzle unit 23 that supplies superheated steam, which is supplied from a measuring device 10 for measuring the volumetric flow rate of superheated steam described below, into the heat treatment chamber 11. The nozzle unit 23 is provided, for example, as a member that extends cylindrically and has both ends in the cylindrical axis direction closed. The nozzle unit 23 is disposed in the heat treatment chamber 11 with its cylindrical axis direction extending horizontally along the width direction of the heat treatment chamber 11. The width direction of the heat treatment chamber 11 is defined as a direction perpendicular to the longitudinal direction (i.e., the transport direction X1) of the heat treatment chamber 11, which extends horizontally, and the height direction (i.e., the up-down direction) of the heat treatment chamber 11.

[0033] The nozzle portion 23 is connected to a second pipe 29 in a measuring device 10 for the volumetric flow rate of superheated steam, which will be described later, at a substantially central position in the cylindrical axial direction. The second pipe 29, which will be described later, penetrates the ceiling wall 11c of the heat treatment chamber 11 and is connected to the nozzle portion 23 in the heat treatment chamber 11. The inside of the nozzle portion 23 and the inside of the second pipe 29 are in communication with each other, and the superheated steam supplied from the second pipe 29 is supplied to the inside of the nozzle portion 23. The nozzle portion 23 is provided with a plurality of nozzle holes 23a that open toward the upstream side and the downstream side in the conveying direction X1. Each nozzle hole 23a is provided as a through hole that opens in, for example, a circular shape. The opening shape of each nozzle hole 23a is not limited to a circular shape, and may be formed in various shapes, such as a rectangular shape, a slit shape, and the like.

[0034] The nozzle holes 23a are provided on both sides of the conveying direction X1 in the nozzle section 23, and are formed to open toward the upstream side and downstream side of the conveying direction X1. The nozzle holes 23a are arranged in a straight line along the cylindrical axial direction of the nozzle section 23 on both the upstream side and downstream side of the conveying direction X1, and are arranged, for example, at equal intervals. Since the cylindrical axial direction of the nozzle section 23 is along the width direction of the heat treatment chamber 11, the nozzle holes 23a in the nozzle section 23 are arranged along the width direction of the heat treatment chamber 11. The superheated steam supplied from the second pipe 29 to the nozzle section 23 fills the nozzle section 23 and is then blown out from the nozzle holes 23a to the outside. The superheated steam is blown out from the nozzle holes 23a, so that the superheated steam is supplied from the nozzle section 23 into the heat treatment chamber 11. Since the above-mentioned water vapor supply section 13 is provided in the heat treatment chamber 11, the heat treatment chamber 11 is configured to introduce superheated water vapor supplied through the second piping 29 in the superheated water vapor volumetric flow rate measuring device 10 described later.

[0035] 1 and 3, the water vapor exhaust section 15 is provided as a mechanism for exhausting superheated water vapor in the heat treatment chamber 11 to the outside of the heat treatment chamber 11. The water vapor exhaust section 15 is provided on the inlet 18 side and the outlet 19 side of the water vapor supply section 13 in the heat treatment chamber 11. An inlet-side water vapor exhaust section 15a is provided as the water vapor exhaust section 15 on the inlet 18 side of the heat treatment chamber 11. An outlet-side water vapor exhaust section 15b is provided as the water vapor exhaust section 15 on the outlet 19 side of the heat treatment chamber 11. In this embodiment, the inlet-side water vapor exhaust section 15a is disposed at a position corresponding to the heating mechanism 12 disposed closest to the inlet 18 side among the multiple heating mechanisms 12 arranged along the transport direction X1 in the heat treatment chamber 11. The outlet-side water vapor exhaust section 15b is disposed at a position corresponding to the heating mechanism 12 disposed closest to the outlet 19 side among the multiple heating mechanisms 12 arranged along the transport direction X1 in the heat treatment chamber 11. The inlet-side water vapor exhaust section 15a and the outlet-side water vapor exhaust section 15b are disposed in the area on the ceiling wall 11c side of the inlet 18 side and the outlet 19 side of the heat treatment chamber 11, respectively, that is, in the upper half of the cross section perpendicular to the transport direction X1 of the heat treatment chamber 11.

[0036] The inlet-side water vapor discharge section 15a and the outlet-side water vapor discharge section 15b are configured in the same manner, and are formed in a hollow box shape extending along the width direction of the heat treatment chamber 11. Each of the inlet-side water vapor discharge section 15a and the outlet-side water vapor discharge section 15b is configured to include an upper wall 24a extending in an arch shape along the ceiling wall 11c in a cross section perpendicular to the transport direction X1, a lower wall 24b extending horizontally, and a pair of side walls extending along a cross section perpendicular to the transport direction X1. As a result, the hollow area inside each of the inlet-side water vapor discharge section 15a and the outlet-side water vapor discharge section 15b is formed as an arc-shaped dome-shaped hollow area surrounded by the upper wall 24a, the lower wall 24b, and the pair of side walls.

[0037] Further, the lower wall 24b of each of the inlet side steam exhaust section 15a and the outlet side steam exhaust section 15b is provided with a plurality of through holes (not shown) for sucking in superheated steam. The superheated steam is sucked in from each of the inlet side steam exhaust section 15a and the outlet side steam exhaust section 15b and exhausted from the heat treatment chamber 11. Each of the inlet side steam exhaust section 15a and the outlet side steam exhaust section 15b is connected to a steam exhaust system (not shown) that sucks in superheated steam from the inlet side steam exhaust section 15a and the outlet side steam exhaust section 15b and exhausts the superheated steam to the outside of the heat treatment chamber 11. The steam exhaust system includes a steam exhaust pipe (not shown) and an ejector (not shown) connected to each of the inlet side steam exhaust section 15a and the outlet side steam exhaust section 15b. The ejector is provided as a mechanism that generates negative pressure using a high-pressure fluid, thereby drawing in superheated steam from each of the inlet side steam exhaust section 15a and the outlet side steam exhaust section 15b via the steam exhaust pipe, and further discharging the drawn-in superheated steam to the outside.

[0038] 1 and 3, the gas supply unit 16 is provided as a mechanism for supplying at least one of an inert gas and air into the heat treatment chamber 11. That is, the gas supply unit 16 is provided as a mechanism for supplying an inert gas such as nitrogen gas into the heat treatment chamber 11, or as a mechanism for supplying air into the heat treatment chamber 11, or as a mechanism for supplying a mixed gas of an inert gas and air into the heat treatment chamber 11. In the heat treatment apparatus 1, an inlet-side gas supply unit 16a and an outlet-side gas supply unit 16b are provided as the gas supply unit 16. The inlet-side gas supply unit 16a is provided on the inlet 18 side of the inlet-side steam exhaust unit 15a provided on the inlet 18 side of the steam supply unit 13 in the heat treatment chamber 11. The outlet-side gas supply unit 16b is provided on the outlet 19 side of the outlet-side steam exhaust unit 15b provided on the outlet 19 side of the steam supply unit 13 in the heat treatment chamber 11.

[0039] The inlet gas supply unit 16a and the outlet gas supply unit 16b are configured in the same manner, and are provided, for example, as a member extending in a cylindrical shape with both ends in the cylindrical axis direction closed. Each of the inlet gas supply unit 16a and the outlet gas supply unit 16b is disposed in the heat treatment chamber 11 with its cylindrical axis direction extending horizontally along the width direction of the heat treatment chamber 11. Each of the inlet gas supply unit 16a and the outlet gas supply unit 16b is connected to a gas supply system (not shown) that supplies gas such as an inert gas or air at a substantially central position in the cylindrical axis direction. Gas is supplied from the gas supply system to the inside of each of the inlet gas supply unit 16a and the outlet gas supply unit 16b. Each of the inlet gas supply unit 16a and the outlet gas supply unit 16b is provided with a plurality of nozzle holes (not shown). The nozzle holes are arranged in a line in the axial direction of the cylinder in each of the inlet side gas supply part 16a and the outlet side gas supply part 16b, for example, arranged at equal intervals. Moreover, the nozzle holes arranged in the axial direction of the cylinder in each of the inlet side gas supply part 16a and the outlet side gas supply part 16b all open downward. Therefore, the inert gas is blown downward from the inlet side gas supply part 16a and the outlet side gas supply part 16b.

[0040] With the above configuration, gas supplied to the inlet-side gas supply unit 16a and the outlet-side gas supply unit 16b is blown downward from the multiple nozzle holes and supplied into the heat treatment chamber 11. Then, by supplying gas from the inlet-side gas supply unit 16a, which is provided closer to the inlet 18 than the inlet-side water vapor exhaust unit 15a, the atmosphere in the heat treatment chamber 11 is separated between the inlet 18 and the inlet-side water vapor exhaust unit 15a. Also, by supplying gas from the outlet-side gas supply unit 16b, which is provided closer to the outlet 19 than the outlet-side water vapor exhaust unit 15b, the atmosphere in the heat treatment chamber 11 is separated between the outlet 19 and the outlet-side water vapor exhaust unit 15b.

[0041] 1, gas curtain section 17 is provided as a mechanism for injecting inert gas so as to form an area where the inert gas spreads in a curtain shape at the end on the inlet 18 side and the end on the outlet 19 side of heat treatment chamber 11. At the end on the inlet 18 side of heat treatment chamber 11, inlet gas curtain section 17a is provided as gas curtain section 17, and at the end on the outlet 19 side of heat treatment chamber 11, outlet gas curtain section 17b is provided as gas curtain section 17.

[0042] The inlet gas curtain section 17a and the outlet gas curtain section 17b each have a gas supply box formed in a hollow box shape and supplied with inert gas from an inert gas supply source (not shown). The gas supply box of the inlet gas curtain section 17a is installed at the end of the heat treatment chamber 11 on the inlet 18 side, and the gas supply box of the outlet gas curtain section 17b is installed at the end of the heat treatment chamber 11 on the outlet 19 side. Each of the gas supply boxes of the inlet gas curtain section 17a and the outlet gas curtain section 17b is provided with a plurality of injection holes communicating with the inside of the heat treatment chamber 11. The plurality of injection holes provided in each gas supply box are configured to inject the inert gas supplied from the inert gas supply source into the inside of the heat treatment chamber 11. The plurality of injection holes of the gas supply boxes of the inlet gas curtain section 17a and the outlet gas curtain section 17b are configured to inject the inert gas so that the inert gas spreads in a curtain shape along a direction parallel to the opening faces of the inlet 18 and the outlet 19. By spraying inert gas in a curtain-like manner from the inlet gas curtain section 17a and the outlet gas curtain section 17b at the inlet 18 and outlet 19 ends of the heat treatment chamber 11, the atmospheres in the inner and outer regions of the heat treatment chamber 11 are separated near the inlet 18 and outlet 19 of the heat treatment chamber 11.

[0043] Referring to FIG. 1, the steam generator 14 is provided as a mechanism for generating saturated steam or superheated steam. When the steam generator 14 is provided as a mechanism for generating saturated steam, the steam generator 14 is configured to include a boiler. In this case, the steam generator 14 is configured to heat and evaporate water in the boiler to generate saturated steam at a temperature approximately equal to the boiling point. When the steam generator 14 is provided as a mechanism for generating superheated steam, the steam generator 14 is configured to include a boiler and a superheater. In this case, the steam generator 14 is configured to heat and evaporate water in the boiler to generate saturated steam at a temperature approximately equal to the boiling point, and further heats the saturated steam generated in the boiler to generate superheated steam in the superheater. The saturated steam or superheated steam generated in the steam generator 14 is sent to a measuring device 10 for the volumetric flow rate of superheated steam.

[0044] FIG. 4 is a diagram showing a measuring device 10 for the volumetric flow rate of superheated steam according to an embodiment of the present invention. In the following description, the measuring device 10 for the volumetric flow rate of superheated steam is also simply referred to as the measuring device 10. With reference to FIG. 1 and FIG. 4, the measuring device 10 provided in the heat treatment device 1 is connected to a steam generator 14, and saturated steam or superheated steam generated by the steam generator 14 is introduced into the measuring device 10. The measuring device 10 is configured to adjust the introduced saturated steam or superheated steam to a predetermined temperature and a predetermined pressure, thereby obtaining superheated steam adjusted to a predetermined temperature and a predetermined pressure. Furthermore, the measuring device 10 is configured to measure the volumetric flow rate of the superheated steam adjusted to a predetermined temperature and a predetermined pressure, and to supply the superheated steam whose volumetric flow rate has been measured to the steam supply unit 13. The measuring device 10 for the volumetric flow rate of superheated steam will be described in more detail below.

[0045] [Superheated steam volumetric flow rate measuring device] 1 and 4, a measuring device 10 for the volumetric flow rate of superheated steam according to an embodiment of the present invention is provided in a heat treatment device 1. The measuring device 10 adjusts saturated steam or superheated steam generated in a steam generator 14 to a predetermined temperature and a predetermined pressure to obtain superheated steam at a predetermined temperature and pressure, measures the volumetric flow rate, and supplies the superheated steam to a steam supplying unit 13. The superheated steam whose volumetric flow rate has been measured by the measuring device 10 is supplied to the steam supplying unit 13, whereby the superheated steam whose volumetric flow rate has been monitored is introduced into the heat treatment chamber 11. The measuring device 10 is configured to include a first pipe 25, a superheated steam adjusting unit 26, an area flow meter 27, a second pipe 28, and the like.

[0046] 1 and 4, the first pipe 25 is connected to the steam generator 14, and configured as a pipe into which saturated steam or superheated steam generated in the steam generator 14 is introduced. The first pipe 25 is configured as, for example, a metal pipe, and configured to be heated from the surroundings by a heater 29 of a superheated steam adjustment unit 26 described later. The saturated steam or superheated steam introduced from the steam generator 14 to the first pipe 25 is heated by the first pipe 25 heated by the heater 29 while flowing through the first pipe 25, and the temperature is adjusted to become superheated steam at a predetermined temperature.

[0047] When saturated steam is introduced from the steam generator 14 to the first piping 25, the introduced saturated steam is heated while flowing through the first piping 25 to become superheated steam, and is further heated until it becomes superheated steam of a predetermined temperature while flowing through the first piping 25. When superheated steam is introduced from the steam generator 14 to the first piping 25, the introduced superheated steam is heated while flowing through the first piping 25 to become superheated steam of a predetermined temperature.

[0048] 1 and 4, the superheated steam adjustment unit 26 is configured as a mechanism for heating saturated steam or superheated steam introduced into the first piping 25 and passing through the first piping 25 to a predetermined temperature and adjusting the temperature to a predetermined pressure, thereby producing superheated steam adjusted to the predetermined temperature and pressure. In this embodiment, the superheated steam adjustment unit 26 is configured to include a heater 29, a pressure adjustment valve 30, a temperature sensor 31, a pressure sensor 32, and a controller 33.

[0049] FIG. 5 is a diagram showing a schematic diagram of the first pipe 25 and the heater 29 in the measuring device 10. Referring to FIG. 4 and FIG. 5, the heater 29 of the superheated steam adjusting unit 26 is provided in the first pipe 25 and is configured to heat the first pipe 25 to heat the saturated steam and the superheated steam passing through the first pipe 25. The superheated steam adjusting unit 26 is configured to heat the first pipe 25 with the heater 29 to heat the saturated steam or the superheated steam passing through the first pipe 25 to a predetermined temperature to produce superheated steam adjusted to the predetermined temperature. In this embodiment, the heater 29 is provided around the first pipe 25 and configured to heat the first pipe 25 from the outside.

[0050] The heater 29 has a heating element 34 arranged around the first pipe 25 so as to be wound around the outer periphery of the first pipe 25 in a spiral shape, and a thermal insulation case 35 surrounding the first pipe 25 and the heating element 34. The heating element 34 is provided so as to generate heat and output it when energized, thereby heating the first pipe 25 and heating the saturated steam and superheated steam flowing through the first pipe 25. The heating element 34 of the heater 29 is connected to a power source (not shown), and the power supplied to the heating element 34 of the heater 29 is configured to be controlled by a controller 33. The power supplied to the heater 29 is controlled by the controller 33, so that the superheated steam flowing through the first pipe 25 while being heated by the heater 29 is heated to a predetermined temperature. The heat-retaining case 35 is provided so as to surround the periphery of the first pipe 25 and the heating element 34 and cover the first pipe 25 and the heating element 34, and is configured to keep the first pipe 25 heated by the heating element 34 warm. The heat-retaining case 35 may be filled with, for example, a thermal insulating material.

[0051] Referring to FIG. 4, the pressure regulating valve 30 of the superheated steam adjusting unit 26 is provided in a second pipe 28 described later. The second pipe 28 is connected to the downstream side of a later-described area flowmeter 27 connected to the downstream side of the first pipe 25, and the superheated steam that has passed through the first pipe 25 further passes through the area flowmeter 27 and is introduced into the second pipe 28. Therefore, the pressure of the upstream superheated steam that passes through the first pipe 25 and flows to the area flowmeter 27 is adjusted by adjusting the valve opening of the pressure regulating valve 30 provided in the downstream second pipe 28. The pressure regulating valve 30 is provided to adjust the superheated steam that passes through the first pipe 25 and is supplied to the area flowmeter 27 so as to be maintained at a predetermined pressure. The superheated steam adjusting unit 26 is configured to adjust the superheated steam that passes through the first pipe 25 and is supplied to the area flowmeter 27 to a predetermined pressure by the pressure regulating valve 30.

[0052] The pressure regulating valve 30 may be any valve that adjusts the upstream superheated steam supplied to the area flow meter 27 through the first pipe 25 so as to maintain the pressure at a predetermined level, and for example, a needle valve that is also used as a flow control valve may be used as the pressure regulating valve 30. The valve opening degree of the pressure regulating valve 30 is configured to be controlled by a controller 33. By controlling the valve opening degree of the pressure regulating valve 30 by the controller 33, the superheated steam supplied to the area flow meter 27 through the first pipe 25 is adjusted to a predetermined pressure.

[0053] The temperature sensor 31 is provided downstream of the first pipe 25 and serves as a sensor for detecting the temperature of the superheated steam that passes through the first pipe 25 and is supplied to the area flow meter 27. The temperature sensor 31 is electrically connected to the controller 33, and the detection value of the temperature of the superheated steam detected by the temperature sensor 31 is transmitted to the controller 33.

[0054] The pressure sensor 32 is provided downstream of the first pipe 25 and serves as a sensor for detecting the pressure of the superheated steam that passes through the first pipe 25 and is supplied to the area flow meter 27. The pressure sensor 32 is electrically connected to the controller 33, and the detection value of the pressure of the superheated steam detected by the pressure sensor 32 is transmitted to the controller 33.

[0055] The controller 33 is provided as a control device that controls the operation of the measuring device 10. The controller 33 is configured to include, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc. The CPU reads out a program corresponding to the processing content from the ROM, loads it into the RAM, and controls the operation of the heater 29 and the pressure regulating valve 30 of the measuring device 10 in cooperation with the loaded program.

[0056] The controller 33 is configured to control the operation of the heater 29 based on the detection value of the temperature of the superheated steam received from the temperature sensor 31 so that the temperature of the superheated steam introduced from the first pipe 25 to the area flow meter 27 becomes a predetermined temperature. That is, the controller 33 is configured to control the output of the heating element 34 of the heater 29 based on the detection value of the temperature sensor 31 so that the temperature of the superheated steam introduced from the first pipe 25 to the area flow meter 27 becomes a predetermined temperature.

[0057] The controller 33 is also configured to control the operation of the pressure regulating valve 30 based on the detection value of the pressure of the superheated steam received from the pressure sensor 32 so that the pressure of the superheated steam introduced from the first pipe 25 to the area flow meter 27 becomes a predetermined pressure. That is, the controller 33 is configured to control the valve opening degree of the pressure regulating valve 30 based on the detection value of the pressure sensor 32 so that the pressure of the superheated steam introduced from the first pipe 25 to the area flow meter 27 becomes a predetermined pressure.

[0058] The superheated steam adjustment unit 26 has a heater 29, a temperature sensor 31, and a controller 33, and is configured to heat the first pipe 25 with the heater 29 to heat the saturated steam or superheated steam passing through the first pipe 25 to a predetermined temperature to produce superheated steam adjusted to the predetermined temperature. The superheated steam adjustment unit 26 has a pressure regulating valve 30, a pressure sensor 32, and a controller 33, and is configured to regulate the superheated steam passing through the first pipe 25 and supplied to the area flowmeter 27 to a predetermined pressure with the pressure regulating valve 30. In this way, the superheated steam adjustment unit 26 is configured to heat the saturated steam or superheated steam passing through the first pipe 25 to a predetermined temperature to regulate it to the predetermined temperature and to regulate it to the predetermined pressure to produce superheated steam adjusted to the predetermined temperature and pressure. The predetermined temperature and predetermined pressure adjusted by the superheated steam adjustment unit 26 are the specific temperature and specific pressure at which the area flow meter 27 to which the superheated steam is introduced from the first pipe 25 is set to measure the volumetric flow rate of the superheated steam. The area flow meter 27 is set to measure the volumetric flow rate of the superheated steam at a predetermined temperature (specific temperature) and a predetermined pressure (specific pressure). The density of the superheated steam adjusted to the predetermined temperature and predetermined pressure becomes a predetermined density determined by the temperature and pressure. The area flow meter 27 is set to measure the volumetric flow rate of the superheated steam adjusted to the predetermined temperature and predetermined pressure and having a predetermined density.

[0059] Fig. 6(A) is a cross-sectional view showing a schematic view of a main part of the area flowmeter 27, and Fig. 6(B) is a cross-sectional view taken along the CC arrow in Fig. 6(A). With reference to Figs. 4 and 6, the area flowmeter 27 is connected to the first pipe 25, is supplied with superheated steam adjusted to a predetermined temperature and a predetermined pressure, and is configured to measure the volumetric flow rate of the superheated steam passing through.

[0060] The area flowmeter 27 is configured to include a flowmeter body 36, a tapered tube 37, a float 38, and the like. The flowmeter body 36 is provided, for example, as a housing to which the first pipe 25 and the second pipe 28 are connected and which houses the tapered tube 37. The first pipe 25 and the second pipe 28 connected to the flowmeter body 36 are connected to the tapered tube 37 inside the flowmeter body 36. A scale 36a is provided on the front surface of the flowmeter body 36 for reading the volumetric flow rate of the superheated steam measured by the area flowmeter 27.

[0061] The tapered tube 37 of the area flowmeter 27 is installed in a state of extending in the vertical direction inside the flowmeter body 36, and is provided as a tube through which the superheated steam introduced from the first pipe 25 is supplied and passes from the bottom to the top. The tapered tube 37 is provided in a tapered shape in which the cross-sectional area gradually increases from the bottom end side to the top end side. The first pipe 25 is connected to the bottom end side of the tapered tube 37, and the first pipe 25 and the inside of the tapered tube 37 are in communication. The second pipe 28 is connected to the top end side of the tapered tube 37, and the inside of the tapered tube 37 and the second pipe 28 are in communication. The superheated steam introduced from the first pipe 25 to the bottom end side of the tapered tube 37 flows from the bottom to the top of the tapered tube 37, and flows from the top end side of the tapered tube 37 to the second pipe 28. In FIG. 6(A), the flow direction of the superheated steam is indicated by a dashed arrow.

[0062] The float 38 of the area flowmeter 27 is disposed inside the tapered pipe 37. The float 38 is provided as a sphere made of metal, ceramic, or resin, for example. The float 38 is configured to move up and down according to the volumetric flow rate of the superheated steam flowing inside the tapered pipe 37.

[0063] The superheated steam that has passed through the first pipe 25 and been adjusted to a predetermined temperature and pressure by the superheated steam adjustment unit 26 is introduced from the first pipe 25 to the lower end side of the tapered pipe 37 and flows from bottom to top in the tapered pipe 37. When the superheated steam flows upward in the tapered pipe 37, the float 38 is positioned at a position where it is balanced with respect to the tapered pipe 37 in relation to the pressure difference between the bottom and top of the float 38 and the gravity and buoyancy acting on the float 38, depending on the volumetric flow rate of the superheated steam flowing upward. Then, the volumetric flow rate of the superheated steam flowing from bottom to top in the tapered pipe 37 is measured based on the position where the float 38 is balanced with respect to the tapered pipe 37. The volumetric flow rate of the superheated steam is measured by reading the scale 36a at the position where the float 38 is balanced.

[0064] The superheated steam introduced into the area flow meter 27 passes through the first pipe 25 and is adjusted to a predetermined temperature and pressure by the superheated steam adjustment unit 26, and becomes superheated steam in a state of temperature and pressure set as a target for measuring the volumetric flow rate by the area flow meter 27. The density of the superheated steam adjusted to a predetermined temperature and pressure becomes a predetermined density determined by the temperature and pressure. The area flow meter 27 is set to measure the volumetric flow rate of the superheated steam adjusted to a predetermined temperature and pressure and having a predetermined density.

[0065] In the area flowmeter 27, the volumetric flow rate Q of the measured superheated steam is expressed by the following formula (1) based on the balance of the forces of the float 38 in the tapered tube 37. Q=C×A×{2×g×Vf / Af×(ρf-ρ0) / ρ0} 1 / 2 ...Equation (1) In the above formula (1), "C" is the discharge coefficient, which is an adjustment coefficient between the theoretical formula and the flow rate obtained by an actual test under the conditions of the area flowmeter 27. "A" represents the flow area, which is the area through which the superheated steam flows between the inner circumference of the tapered tube 37 and the outer circumference of the float 38 at the position where the float 38 is balanced. That is, "A" is the difference area between the cross-sectional area of ​​the inner circumference of the tapered tube 37 at the position where the float 38 is balanced and the cross-sectional area of ​​the maximum diameter part of the float 38, which is the area indicated by the symbol A in FIG. 6(B). "g" is the gravitational acceleration. "Vf" is the volume of the float 38. "Af" is the cross-sectional area of ​​the maximum diameter part of the float 38, which is the area of ​​the region indicated by the double-ended arrow and the symbol Af in FIG. 6(B). "ρf" is the density of the float. "ρ0" is the density of the superheated steam adjusted to a specified temperature and a specified pressure.

[0066] In the above formula (1), the flow coefficient C, the acceleration of gravity g, the volume Vf of the float 38, the cross-sectional area Af of the maximum diameter part of the float 38, and the density ρf of the float 38 are fixed values, and the density ρ0 of the superheated steam to be measured is also a fixed value because the superheated steam is adjusted to a specified pressure and a specified temperature. For this reason, in the area flowmeter 27, there is a fixed relationship between the flow area A determined by the position of the float 38 in the tapered tube 37 and the volumetric flow rate Q of the passing superheated steam, and the volumetric flow rate Q of the superheated steam is measured by detecting this position.

[0067] Note that the measurement of the volumetric flow rate of superheated steam by the area flowmeter 27 does not have to be done by reading the graduations 36a. For example, the volumetric flow rate of superheated steam may be measured by providing a magnet to the float 38 and detecting the magnitude of the magnetic force from the magnet to magnetically detect the position of the float 38 relative to the tapered tube 37. In this case, the area flowmeter 27 is configured to display the measured value of the volumetric flow rate measured by magnetically detecting the position of the float 38 relative to the tapered tube 37.

[0068] 1 and 4, the second pipe 28 is connected to the area flowmeter 27 and configured as a pipe into which the superheated steam whose volumetric flow rate has been measured by passing through the area flowmeter 27 is introduced. Furthermore, the second pipe 28 is configured as a pipe for supplying superheated steam to a supply destination of the superheated steam, and configured to supply superheated steam to the heat treatment chamber 11 which is the supply destination of the superheated steam. Specifically, the upstream end of the second pipe 28 is connected to the upper end of the tapered tube 37 of the area flowmeter 27, and the downstream end of the second pipe 28 is connected to the steam supply unit 13 arranged in the heat treatment chamber 11. The superheated steam whose volumetric flow rate has been measured by the area flowmeter 27 is introduced into the second pipe 28, flows through the second pipe 28, and is supplied to the steam supply unit 13 arranged in the heat treatment chamber 11. The superheated steam supplied to the steam supply unit 13 is supplied from the steam supply unit 13 into the heat treatment chamber 11.

[0069] The second pipe 28 is provided with a pressure regulating valve 30 of the superheated steam adjusting unit 26. The second pipe 28 is, for example, configured as a metal pipe and configured to be heated from the surroundings by a second heater 39. The superheated steam introduced from the area flowmeter 27 and passed through the second pipe 28 to be supplied to the heat treatment chamber 11, which is the supply destination of the superheated steam, is heated by the second pipe 28 heated by the second heater 39 while flowing through the second pipe 28, and is kept warm.

[0070] The second heater 39 is configured similarly to the heater 29 provided in the first pipe 25, and includes a heating element 34 (not shown) arranged around the second pipe 28 so as to be spirally wound around the outer periphery of the second pipe 28, and a thermal insulation case 35 (not shown) surrounding the second pipe 28 and the heating element 34. The heating element 34 of the second heater 39 is connected to a power source (not shown), and the power supplied to the heating element 34 of the second heater 39 is controlled by the controller 33. By controlling the power supplied to the second heater 39 by the controller 33, the superheated steam flowing through the second pipe 28 while being heated by the second heater 39 is kept warm.

[0071] [Method for measuring the volumetric flow rate of superheated steam] Next, a method for measuring the volumetric flow rate of superheated steam according to an embodiment of the present invention will be described. Fig. 7 is a flow chart for explaining the method for measuring the volumetric flow rate of superheated steam according to an embodiment of the present invention. The method for measuring the volumetric flow rate of superheated steam according to this embodiment (hereinafter also simply referred to as "the measurement method of this embodiment") is configured as a method for adjusting saturated steam or superheated steam generated in steam generator 14 to a predetermined temperature and pressure to produce superheated steam at a predetermined temperature and pressure, measuring the volumetric flow rate, and supplying it to steam supply unit 13, and is implemented using measurement device 10.

[0072] 7, the measurement method of this embodiment includes a steam introduction step S1, a superheated steam adjustment step S2, a measurement step S3, and a supply step S4. In the measurement method of this embodiment, the above steps S1 to S4 are performed to measure the volumetric flow rate of superheated steam supplied to the heat treatment chamber 11 as the supply destination of the superheated steam, and the superheated steam whose volumetric flow rate has been measured is continuously supplied to the heat treatment chamber 11.

[0073] The water vapor introduction step S1 is configured as a step of introducing saturated water vapor or superheated water vapor into the first piping 25. With reference to Fig. 1 and Fig. 4, in the water vapor introduction step S1, the saturated water vapor or superheated water vapor generated in the water vapor generator 14 is introduced into the first piping 25 connected to the water vapor generator 14. The saturated water vapor or superheated water vapor introduced into the first piping 25 flows through the first piping 25.

[0074] The superheated steam preparation process S2 is configured as a process of heating the saturated steam or superheated steam introduced into the first piping 25 and passing through the first piping 25 to a predetermined temperature and adjusting it to a predetermined pressure, thereby producing superheated steam adjusted to the predetermined temperature and pressure.

[0075] 4, the superheated steam preparation step S2 is configured to heat the first pipe 25 with a heater 29 provided in the first pipe 25, thereby heating the saturated steam or superheated steam passing through the first pipe 25 to a predetermined temperature to obtain superheated steam adjusted to the predetermined temperature. That is, in the superheated steam preparation step S2, the saturated steam or superheated steam introduced from the steam generator 14 to the first pipe 25 is heated by the first pipe 25 heated by the heater 29 while flowing through the first pipe 25, and the temperature is adjusted by being heated to become superheated steam of a predetermined temperature. Note that, when saturated steam is introduced from the steam generator 14 to the first pipe 25, the introduced saturated steam is heated while flowing through the first pipe 25 to become superheated steam, and is further heated while flowing through the first pipe 25 until it becomes superheated steam of a predetermined temperature. When superheated steam is introduced from the steam generator 14 to the first pipe 25, the introduced superheated steam is heated to a predetermined temperature while flowing through the first pipe 25. In the superheated steam adjustment step S2, the power supplied to the heater 29 is controlled by the controller 33, so that the superheated steam flowing through the first pipe 25 while being heated by the heater 29 is heated to a predetermined temperature. In the superheated steam adjustment step S2, the controller 33 controls the operation of the heater 29 based on the detected value of the temperature of the superheated steam received from the temperature sensor 31, so that the temperature of the superheated steam introduced from the first pipe 25 to the area flow meter 27 becomes a predetermined temperature.

[0076] A second pipe 28 connected to the downstream side of the area flowmeter 27 connected to the downstream side of the first pipe 25 is provided with a pressure regulating valve 30 for regulating the superheated steam supplied to the area flowmeter 27 through the first pipe 25 so as to maintain the pressure at a predetermined level. In the superheated steam regulating step S2, the pressure regulating valve 30 regulates the superheated steam supplied to the area flowmeter 27 through the first pipe 25 to a predetermined level. In the superheated steam regulating step S2, the controller 33 controls the valve opening of the pressure regulating valve 30 so that the pressure of the superheated steam supplied to the area flowmeter 27 through the first pipe 25 is adjusted to a predetermined level. In the superheated steam regulating step S2, the controller 33 controls the valve opening of the pressure regulating valve 30 based on the detection value of the pressure of the superheated steam received from the pressure sensor 32 so that the pressure of the superheated steam introduced from the first pipe 25 to the area flowmeter 27 is a predetermined pressure.

[0077] The measuring step S3 is configured as a step of supplying superheated steam adjusted to a predetermined temperature and a predetermined pressure to the area flowmeter 27 connected to the first pipe 25, and measuring the volumetric flow rate of the superheated steam passing through the area flowmeter 27 with the area flowmeter 27. With reference to Fig. 4 and Fig. 6, in the measuring step S3, the superheated steam adjusted to a predetermined temperature and a predetermined pressure while passing through the first pipe 25 in the superheated steam adjusting step S2 is introduced from the first pipe 25 to the lower end side of the tapered pipe 37 of the area flowmeter 27, and flows from the bottom to the top of the tapered pipe 37. When the superheated steam flows upward through the tapered pipe 37, the float 38 of the area flowmeter 27 is positioned at a position balanced with the tapered pipe 37 in relation to the pressure difference between the bottom and top of the float 38 and the gravity and buoyancy acting on the float 38, according to the volumetric flow rate of the superheated steam flowing upward. Then, in a measurement step S3, the volumetric flow rate of the superheated steam flowing from bottom to top through tapered tube 37 is measured based on the position where float 38 is balanced with respect to tapered tube 37. The volumetric flow rate of the superheated steam is measured by reading scale 36a at the position where float 38 is balanced.

[0078] The superheated steam supplied to the area flowmeter 27 in the measurement step S3 has passed through the first pipe 25 in the superheated steam adjustment step S2 and been adjusted to a predetermined temperature and pressure, and is now superheated steam in a state of temperature and pressure set as a target for the measurement of the volumetric flow rate by the area flowmeter 27. The density of the superheated steam adjusted to a predetermined temperature and pressure becomes a predetermined density determined by the temperature and pressure. In the measurement step S3, the volumetric flow rate of the superheated steam is measured by the area flowmeter 27 set to measure the volumetric flow rate of the superheated steam adjusted to a predetermined temperature and pressure and having a predetermined density.

[0079] The supply step S4 is configured as a step of introducing the superheated steam that has passed through the area flowmeter 27 into the second pipe 28, and supplying the superheated steam through the second pipe 28 to the heat treatment chamber 11, which is the supply destination of the superheated steam. With reference to Figs. 1 and 4, in the supply step S4, the superheated steam whose volumetric flow rate has been measured by passing through the area flowmeter 27 in the measurement step S3 is introduced into the second pipe 28 connected to the tapered tube 37 of the area flowmeter 27. Then, the superheated steam introduced into the second pipe 28 flows through the second pipe 28 and is supplied to the steam supply unit 13 arranged in the heat treatment chamber 11. The superheated steam supplied to the steam supply unit 13 is supplied from the steam supply unit 13 into the heat treatment chamber 11.

[0080] [Actions and Effects of the Present Embodiment] According to this embodiment, the saturated steam or superheated steam passing through the first pipe 25 is adjusted to superheated steam at a predetermined temperature and pressure, and becomes superheated steam as a measurement target of the volumetric flow rate. The superheated steam is adjusted to a predetermined density by being adjusted to a predetermined temperature and pressure. Then, the superheated steam adjusted to a predetermined density passes through the area flowmeter 27 connected to the first pipe 25, and the volumetric flow rate is measured by the area flowmeter 27. The area flowmeter 27 has a tapered pipe 37 and a float 38 that moves up and down according to the volumetric flow rate of the superheated steam flowing inside the tapered pipe 37, and the volumetric flow rate is measured based on the position where the float 38 is balanced with respect to the tapered pipe 37. The area flowmeter 27 measures the volumetric flow rate of the superheated steam based on the position where the float 38 is balanced by passing the superheated steam adjusted to a predetermined density. The superheated steam whose volumetric flow rate has been measured is continuously supplied through second pipe 28 to heat treatment chamber 11, which is the supply destination of the superheated steam.

[0081] Therefore, according to this embodiment, it is possible to measure and monitor the volume flow rate of superheated steam continuously supplied to the heat treatment chamber 11, which is the supply destination of the superheated steam.

[0082] In addition, when the workpiece 100 to be heat-treated by heating with superheated steam in the heat treatment device 1 is a ceramic electronic component such as a multilayer ceramic capacitor, a small amount of hydrogen is added to the atmosphere in the heat treatment chamber 11. The circuit of the ceramic electronic component contains metal, and a small amount of hydrogen is added to the atmosphere in the heat treatment chamber 11 to prevent the metal from being oxidized during heat treatment. For this reason, when the workpiece 100 is a ceramic electronic component, a small amount of hydrogen is supplied to the heat treatment chamber 11 together with the superheated steam. At this time, in the heat treatment device 1, the concentration of hydrogen may be controlled according to the heat treatment, and for this purpose, it is necessary to accurately grasp the volumetric flow rate of the superheated steam introduced into the heat treatment chamber 11 and the volumetric flow rate of other gases. In contrast, according to this embodiment, the measuring device 10 can measure and monitor the volumetric flow rate of the superheated steam continuously supplied to the heat treatment chamber 11. Therefore, according to this embodiment, the volumetric flow rate of the superheated steam introduced into the heat treatment chamber 11 can be accurately grasped, and the concentration of hydrogen can be more accurately controlled.

[0083] Furthermore, according to this embodiment, by providing a pressure regulating valve 30 in the second pipe 28 downstream of the area flowmeter 27, the pressure of the superheated steam supplied from the first pipe 25 upstream of the area flowmeter 27 to the area flowmeter 27 can be easily adjusted to a predetermined pressure.

[0084] If the superheated steam to be measured for the volumetric flow rate condenses, the amount of water vapor corresponding to the condensation cannot be measured. However, according to the present embodiment, by providing the pressure regulating valve 30 in the second pipe 28 downstream of the area flowmeter 27, it is possible to prevent the superheated steam supplied to the area flowmeter 27 from condensing and becoming unable to accurately measure the volumetric flow rate of the superheated steam. With reference to FIG. 4, when the pressure regulating valve 30 is provided in the second pipe 28 downstream of the area flowmeter 27, the pressure upstream of the pressure regulating valve 30 becomes approximately the same. That is, the pressures in the second pipe 28, the area flowmeter 27, and the first pipe 25, which are upstream of the pressure regulating valve 30, become approximately the same, and the pressure can be approximately the same from the pressure regulating valve 30 to the connection part of the first pipe 25 to the steam generator 14. In contrast, when the pressure regulating valve 30 is provided in the first pipe 25 upstream of the area flowmeter 27, the pressure upstream of the pressure regulating valve 30 becomes high and the pressure downstream of the pressure regulating valve 30 becomes low. If the open end of the second pipe 28 is open to the atmosphere, the pressure downstream of the pressure regulating valve 30 will be atmospheric pressure. Since the pressure downstream of the pressure regulating valve 30 is lower than that upstream, the boiling point of the superheated steam passing downstream may drop due to the pressure drop, and the superheated steam may easily condense and condense. However, according to this embodiment, the pressure regulating valve 30 is provided on the second pipe 28 downstream of the area flowmeter 27, so that condensation of the superheated steam supplied to the area flowmeter 27 can be prevented, and the volumetric flow rate of the superheated steam cannot be accurately measured due to condensation.

[0085] Furthermore, according to this embodiment, by providing a heater 29 in the first piping 25 and heating the first piping 25, the temperature of the superheated steam passing through the first piping 25 and supplied to the area flow meter 27 can be easily adjusted to a predetermined temperature.

[0086] [Variations] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and can be modified in various ways within the scope of the claims. For example, the following modified examples may be implemented.

[0087] In the above embodiment, the heat treatment apparatus 1 is provided with one measuring device 10, but this is not necessarily the case. The heat treatment apparatus 1 may be provided with a plurality of measuring devices 10. For example, the heat treatment apparatus 1 may be provided with one steam generator 14, and a plurality of supply paths for superheated steam from the steam generator 14 to the heat treatment chamber 11 may be provided, and a measuring device 10 may be provided for each of the plurality of supply paths. In this case, even if the number of steam generators 14 provided in the heat treatment apparatus 1 is one, the volumetric flow rate of superheated steam continuously supplied to the heat treatment chamber 11 through the plurality of supply paths can be measured and monitored in each supply path. Therefore, the number of steam generators 14 installed can be reduced, thereby reducing costs.

[0088] In the above embodiment, the heater 29 is provided around the first pipe 25 and configured to heat the first pipe 25 from the outside, but this is not essential. As a heater provided in the first pipe 25 for heating the superheated steam passing through the first pipe 25, for example, a heater having a heating element disposed inside the first pipe 25 and directly heating the superheated steam passing through the first pipe 25 may be implemented.

[0089] In the above embodiment, the pressure regulating valve 30 is provided in the second pipe 28 to adjust the pressure of the superheated steam supplied to the area flow meter 27 through the first pipe 25 so as to maintain the pressure at a predetermined level, and the superheated steam adjusting unit 26 adjusts the pressure of the superheated steam supplied to the area flow meter 27 to a predetermined level by the pressure regulating valve 30, but this is not essential. A pressure regulating valve may be provided to adjust the pressure of the saturated steam or superheated steam supplied to the first pipe 25, and the controller 33 of the superheated steam adjusting unit 26 may control the pressure regulating valve based on the detection result of the pressure sensor 32 to adjust the pressure of the superheated steam supplied to the area flow meter 27 through the first pipe 25 to a predetermined level.

[0090] In the above embodiment, the float 38 of the area flowmeter 27 is a sphere, but this is not essential. The shape of the float of the area flowmeter 27 may be of various shapes, and for example, a float having a shape that combines a conical shape and a cylindrical shape may be used.

[0091] In the above embodiment, the saturated steam or superheated steam introduced into the first pipe 25 is heated to adjust the temperature of the superheated steam supplied to the area flowmeter 27 to a predetermined temperature, but this is not necessarily the case. A configuration may be implemented in which the superheated steam is introduced into the first pipe 25, and the superheated steam introduced into the first pipe 25 and passing through the first pipe 25 is cooled to adjust the temperature of the superheated steam supplied to the area flowmeter 27 to a predetermined temperature. For example, the temperature of the superheated steam introduced into the first pipe 25 may be set slightly higher than the predetermined temperature, and the temperature of the superheated steam may be reduced during the process of passing through the first pipe 25, and the temperature of the superheated steam may be reduced to the predetermined temperature and supplied to the area flowmeter 27. In this case, for example, first, data on the relationship between the material and length of the first pipe 25 and the temperature of the superheated steam in the first pipe 25 is experimentally obtained in advance so that the temperature of the superheated steam passing through the first pipe 25 can be appropriately reduced to the predetermined temperature. Based on this data, the first pipe 25 is set to an appropriate material and length to lower the temperature of the superheated steam so that the temperature of the superheated steam becomes a predetermined temperature at the connection part of the first pipe 25 connected to the upstream side of the area flowmeter 27 to the area flowmeter 27, thereby adjusting the temperature of the superheated steam supplied to the area flowmeter 27 to a predetermined temperature. Also, a mode may be implemented in which the temperature of the superheated steam introduced into the first pipe 25 and passing through the first pipe 25 is maintained to adjust the temperature of the superheated steam supplied to the area flowmeter 27 to a predetermined temperature. For example, the temperature of the superheated steam introduced into the first pipe 25 may be set to a temperature approximately equal to the predetermined temperature, and the first pipe 25 may be covered with a heat insulating material so that the temperature does not decrease during the process of passing through the first pipe 25. [Industrial Applicability]

[0092] INDUSTRIAL APPLICABILITY The present invention can be widely applied as a method for measuring a volumetric flow rate of superheated steam, an apparatus for measuring a volumetric flow rate of superheated steam, and a heat treatment apparatus equipped with a apparatus for measuring a volumetric flow rate of superheated steam. [Explanation of symbols]

[0093] 1 Heat treatment equipment 10. Apparatus for measuring the volumetric flow rate of superheated steam 11 Heat treatment room (superheated steam supply destination) 25 First Pipe 26 Superheated steam adjustment section 27 Area flow meter 28 Second Pipe 29 Heater 30 Pressure Regulating Valve S1 Water vapor introduction process S2 Superheated steam adjustment process S3 measurement process S4 Supply process

Claims

1. A steam introduction step of introducing saturated steam or superheated steam into a first pipe; a superheated steam adjustment step of adjusting the saturated steam or superheated steam introduced into the first pipe and passing through the first pipe to a predetermined temperature and a predetermined pressure to obtain superheated steam adjusted to the predetermined temperature and the predetermined pressure; a measuring step of supplying superheated steam adjusted to the predetermined temperature and the predetermined pressure to an area flow meter connected to the first pipe, and measuring a volumetric flow rate of the superheated steam passing through the area flow meter with the area flow meter; a supply step of introducing the superheated steam that has passed through the area flow meter into a second pipe and supplying the superheated steam to a supply destination of the superheated steam through the second pipe; A method for measuring a volumetric flow rate of superheated steam, comprising:

2. 2. A method for measuring a volumetric flow rate of superheated steam according to claim 1, a pressure regulating valve is provided in the second pipe to regulate the pressure of the superheated steam passing through the first pipe and supplied to the area flow meter so as to maintain the pressure at the predetermined pressure; a pressure adjusting valve for adjusting the pressure of the superheated steam supplied to the area flow meter through the first pipe to the pressure adjusting valve,

3. 3. A method for measuring a volumetric flow rate of superheated steam according to claim 1 or 2, comprising: The method for measuring a volumetric flow rate of superheated steam, wherein the superheated steam adjustment step comprises heating the first piping with a heater provided in the first piping, thereby heating the saturated steam or superheated steam passing through the first piping to the predetermined temperature, thereby producing superheated steam adjusted to the predetermined temperature.

4. a first pipe into which saturated steam or superheated steam is introduced; a superheated steam adjusting unit that adjusts the saturated steam or superheated steam introduced into the first pipe and passing through the first pipe to a predetermined temperature and a predetermined pressure, thereby producing superheated steam adjusted to the predetermined temperature and the predetermined pressure; an area flow meter connected to the first pipe, to which superheated steam adjusted to the predetermined temperature and the predetermined pressure is supplied and which measures a volumetric flow rate of the superheated steam passing through; a second pipe into which the superheated steam that has passed through the area flow meter is introduced and which supplies the superheated steam to a supply destination of the superheated steam; A device for measuring a volumetric flow rate of superheated steam, comprising:

5. The device for measuring a volumetric flow rate of superheated steam according to claim 4, the superheated steam adjustment unit has a pressure adjustment valve provided in the second pipe and configured to adjust the superheated steam passed through the first pipe and supplied to the area flow meter so as to maintain the predetermined pressure, The superheated steam adjustment unit adjusts the pressure of the superheated steam supplied to the area flow meter through the first pipe to the predetermined pressure by the pressure regulating valve.

6. The device for measuring a volumetric flow rate of superheated steam according to claim 4 or 5, The superheated steam adjustment unit has a heater provided in the first piping, and heats the first piping with the heater, thereby heating saturated steam or superheated steam passing through the first piping to the predetermined temperature, thereby producing superheated steam adjusted to the predetermined temperature.

7. A heat treatment apparatus for heating a workpiece with superheated steam to perform heat treatment on the workpiece, a heat treatment chamber in which the heat treatment of the workpiece is performed; The device for measuring a volumetric flow rate of superheated steam according to any one of claims 4 to 6, Equipped with The heat treatment apparatus, wherein the heat treatment chamber is introduced with superheated steam supplied through the second pipe.

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