Moisture removal device and moisture removal method

Abstract

To provide a moisture removal device and the like that efficiently remove moisture of a moisture-containing liquid.SOLUTION: A moisture-containing liquid filled into a container is irradiated with microwaves, and a distance between a surface of the liquid filled into the container, and an emission part for emitting microwaves is held at a predetermined distance.SELECTED DRAWING: Figure 2

Description

【Technical Field】 【0001】 This invention relates to a water removal device for removing water from a liquid containing water. 【Background Art】 【0002】 In some nuclear reactors, in order to condense the high-temperature steam that fills the reactor containment vessel during abnormal times, an ice condenser containing a plurality of block ice is installed. As disclosed in Patent Document 1, the block ice is, for example, composed of ice containing borax (Na2B4O7·10H2O) to promote the absorption of neutrons, and a water-soluble polymer polyvinyl alcohol (PVA) is adhered to the outer periphery thereof to prevent or suppress the sublimation of the block ice body. 【Prior Art Documents】 【Patent Documents】 【0003】 【Patent Document 1】 Japanese Patent No. 3876241 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0004】 When decommissioning a nuclear reactor equipped with an ice condenser, it is necessary to remove the water from the liquid formed by thawing the block ice with PVA adhered thereto, and properly dispose of the remaining PVA and borax. 【0005】 Therefore, an object of this invention is to provide a water removal device or the like that can efficiently remove the water from a liquid containing water. 【Means for Solving the Problems】 【0006】 This invention has been made to achieve the above object, and is characterized by the following. 【0007】 The invention described in claim 1 comprises: an irradiation means for irradiating a liquid containing water in a container with microwaves; and a distance-maintaining means for maintaining a predetermined distance between the surface of the liquid in the container and an emission part of the irradiation means that emits the microwaves. The distance-maintaining means is a float provided at the injection unit that floats on the liquid, and the float is sized such that when it floats on the liquid, the distance between the surface of the liquid and the injection unit is the predetermined distance. It is characterized by the following: 【0008】 The invention described in claim 2 is, A heating means that heats and thaws a solid to make it liquid, an irradiation means that irradiates microwaves onto the liquid containing water in a container, and a distance-holding means that maintains a predetermined distance between the surface of the liquid in the container and the microwave-emitting part of the irradiation means, The system comprises a storage compartment for housing the aforementioned container, and a discharge means for discharging water vapor from the storage compartment. The heating means heats using the heat of the steam discharged by the discharge means. It is characterized by the following: 【0009】 The invention described in claim 3 is, 1 A moisture removal device as described above, The system comprises a storage compartment for housing the aforementioned container, and a discharge means for discharging water vapor from the storage compartment. It is characterized by the following: 【0010】 The invention described in claim 4 is the same as claim 1 any one of claims 3 A moisture removal device as described above, The irradiation means further comprises a preheating means for heating the liquid before irradiating it with microwaves. It is characterized by the following: 【0011】 The invention described in claim 5 is, The method includes an irradiation step of irradiating a liquid containing water in a container with microwaves, and a distance-maintaining step of maintaining a predetermined distance between the surface of the liquid in the container and an emission unit that emits the microwaves in the irradiation step, wherein in the distance-maintaining step, a float having a size such that the distance between the surface of the liquid and the emission unit becomes the predetermined distance when floated on the liquid is placed on the surface of the liquid, and the emission unit descends in accordance with the descent of the float, thereby maintaining the distance between the surface of the liquid and the emission unit at the predetermined distance. 【0012】 The invention described in claim 6 is, The method includes a heating step of heating a solid to thaw it into a liquid, an irradiation step of irradiating the liquid containing water in a container with microwaves, and a distance-holding step of maintaining a predetermined distance between the surface of the liquid in the container and the emitting part that emits the microwaves in the irradiation step, wherein the heating step is characterized by using the heat of water vapor discharged from a storage unit that houses the container. [Effects of the Invention] 【0016】 According to this invention, when evaporating water from a liquid by irradiating it with microwaves, the microwave irradiation can be continued while maintaining a predetermined distance between the microwave emitter and the liquid surface. By setting this predetermined distance to the optimal distance for evaporating the water, the water from the liquid can be efficiently removed. [Brief explanation of the drawing] 【0017】 [Figure 1] (A) is a schematic internal plan view of an example of the moisture removal device in this embodiment, (B) is a schematic internal front view of the same example of the moisture removal device, and (C) is a schematic internal side view of the same example of the moisture removal device in this embodiment. [Figure 2] (A) is a schematic internal front view (t = t0) of an example of the water removal device of Example 1, and (B) is a schematic internal front view (t = t1) of an example of the water removal device of Example 1. [Figure 3] (A) is a schematic internal front view (t = t0) of an example of the water removal device of Example 2, (B) is a schematic internal front view (t = t1) of an example of the water removal device of Example 2, and (C) is a partially enlarged view of an example of the waveguide 3 and the float 12. [Figure 4] (A) is a schematic internal front view (t = t0) of an example of the water removal device of Example 3, and (B) is a schematic internal front view (t = t1) of an example of the water removal device of Example 3. [Figure 5] It is a schematic front view of an example of the water removal device of Example 4. [Figure 6] It is a flowchart showing an example of the water removal method in this embodiment. [Figure 7] (A) is data of the experimental results of water removal according to this embodiment, and (B) is a graph of the same data. 【Mode for Carrying Out the Invention】 【0018】 Embodiments of this invention will be described while referring to the drawings. In this embodiment, an example of removing the moisture of the liquid formed by thawing the block ice used in the nuclear reactor will be described. Note that this invention can also be applied to liquids containing moisture other than the liquid formed by thawing the block ice. 【0019】 First, block ice will be described. The block ice is cylindrical, and its main body is composed of ice containing borax (Na2B4O7·10H2O) to promote neutron absorption. On the outer periphery of the ice, water-soluble polymer polyvinyl alcohol is adhered to prevent or suppress the sublimation of the ice. The film made of PVA is adhered to the outer surface of the ice by full or partial welding by heat treatment with a dryer or the like on the outer surface of the ice. Note that the film made of PVA is preferably an addition product with a PVA polymerization degree of 1700, a saponification degree of 88 mol%, 0.8 wt% borax, and a thickness of about 15 μm. 【0020】 Next, the basic configuration of the moisture removal device A will be described using FIG. 1. The moisture removal device A includes a storage 1 in which a container 2 containing a liquid W is stored, a waveguide 3 (an example of "irradiation means") that irradiates the liquid W with microwaves M oscillated by a microwave oscillator (not shown), a base 4 that supports the container 2, an air supply port 5 for supplying air to the storage 1, and an exhaust port 6 for discharging the water vapor S in the storage 1 to the outside of the storage 1. 【0021】 The waveguide 3 has an emission part 3A that emits microwaves M. The microwaves M emitted from the emission part 3A vibrate the moisture (water molecules) in the liquid W, generate heat, and evaporate it, thereby removing the moisture in the liquid W. When the moisture in the liquid W evaporates, the amount of water vapor in the storage 1 increases and the removal efficiency of the moisture in the liquid W decreases. Therefore, air (preferably dry air) is supplied from the air supply port 5 by an air supply fan (not shown), and the water vapor S is exhausted from the exhaust port 6 by an exhaust fan (not shown) (an example of "discharge means") to reduce the amount of water vapor in the storage 1. 【0022】 The frequency of the microwave M is preferably 500 kHz to 6 GHz (wavelength 5 cm to 60 m). Furthermore, by setting the distance h between the emission section 3A and the surface of the liquid W to a predetermined distance that is optimal for evaporating the water in the liquid W, the water in the liquid W can be efficiently removed. This predetermined distance is set based on the size and material of the container 2, the frequency of the microwave M, etc. Therefore, the water removal device A of Example 1-4 described later is equipped with a distance-holding mechanism (an example of a "distance-holding means") that maintains the distance h at a predetermined distance. 【0023】 [Example 1] The moisture removal apparatus A in Example 1 will be explained using Figure 2. Figure 2(A) shows the state before irradiation with microwave M (t=t0), and Figure 2(B) shows the state after a certain period of time has elapsed since the start of irradiation with microwave M (t=t1). In Example 1, the explanation will focus on the differences from the moisture removal apparatus A shown in Figure 1, and the explanation of identical components will be omitted. 【0024】 The moisture removal device A of Example 1 has a spring base 11 instead of a base 4. The spring base 11 includes a spring 11A (an example of a "distance holding means") and a mounting plate 11B on which the container 2 is placed. The spring base 11 maintains a predetermined distance h by raising the container 2 with the force of the spring 11A in response to the evaporation of moisture from the liquid W causing the surface (liquid level) of the liquid W to drop relative to the container 2 (decreasing the weight of the liquid W). 【0025】 In Figure 2, the spring 11A is positioned below the container 2, and the force of the spring 11A returning to its original position after being compressed by the weight of the container 2 and the liquid W is used to maintain the distance h at a predetermined distance. However, instead, one end of the spring 11A may be attached to the ceiling of the storage compartment 1, and the other end of the spring 11A may be attached to the mounting plate 11B (or container 2), and the force of the spring 11A returning to its original position after being stretched by the weight of the container 2 and the liquid W is used to maintain the distance h at a predetermined distance. 【0026】 [Example 2] The moisture removal apparatus A in Example 2 will be explained using Figure 3. Figure 3(A) shows the state before irradiation with microwave M (t=t0), and Figure 3(B) shows the state after a certain period of time has elapsed since the start of irradiation with microwave M (t=t1). Note that the explanation will focus on the differences from the moisture removal apparatus A shown in Figure 1, and the explanation of identical components will be omitted. 【0027】 As shown in Figure 3(C), the moisture removal device A of Example 2 is equipped with a float 12 (an example of a "distance-maintaining means") at the bottom of the waveguide 3. The float 12 is made of a heat-resistant material and has buoyancy that allows it to float on the surface of the liquid W while supporting the waveguide 3. The float 12 is also sized such that when it floats on the liquid W, the distance h between the liquid W surface and the outlet 3A is a predetermined distance. On the other hand, the waveguide 3 of Example 2 is configured to be able to move up and down. As a result, as the moisture in the liquid W evaporates and the liquid W surface drops relative to the container 2 (the weight of the liquid W decreases), the float 12 and the waveguide 3 also descend, so that the distance h is maintained at a predetermined distance. 【0028】 [Example 3] The moisture removal apparatus A in Example 3 will be explained using Figure 4. Figure 4(A) shows the state before irradiation with microwave M (t=t0), and Figure 4(B) shows the state after a certain period of time has elapsed since the start of irradiation with microwave M (t=t1). In Example 3, the explanation will focus on the differences from the moisture removal apparatus A shown in Figure 1, and the explanation of identical components will be omitted. 【0029】 The moisture removal device A of Example 3 has a wire 13, a jack 14 (an example of a "distance-maintaining means") and a mounting platform 15 instead of a base 4. The wire 13 is attached to the mounting platform 15 on which the container 2 is placed, and the jack 14 raises and lowers the mounting platform 15 via the wire 13. That is, the jack 14 raises the wire 13 and raises the container 2 in response to the evaporation of moisture from the liquid W causing the surface (liquid level) of the liquid W to drop relative to the container 2 (decreasing the weight of the liquid W), thereby maintaining the distance h at a predetermined distance. 【0030】 In Figure 4, the jack 14 is positioned above the container 2, and the container 2 and liquid W are lifted via the wire 13 to maintain a predetermined distance h. However, instead, a hydraulic jack (not shown) (an example of a "distance-maintaining means") that pushes up a heavy object placed on top may be positioned below the container 2 (for example, the mounting base 15), and the container 2 and liquid W may be pushed up by the hydraulic jack to maintain a predetermined distance h. 【0031】 [Example 4] The moisture removal device A in Example 4 will be explained using Figure 5. Note that the explanation will focus on the differences from the moisture removal device A shown in Figure 1, and the same components will be omitted. 【0032】 In Embodiment 4, container 2 forms a connecting pipe with a second container 16 (an example of a "second container") located outside the storage compartment 1. That is, the bottom of container 2 and the bottom of the second container 16 are connected by a pipe 17. As a result, the liquid level in container 2 and the liquid level in the second container 16 are at the same height. The moisture removal device A also has a supply unit 18 (an example of a "distance-maintaining means") that supplies liquid W to the second container 16. The supply unit 18 has, for example, a storage tank (not shown) for storing liquid W, and controls the opening and closing of the stopper of the storage tank in response to the evaporation of moisture in the liquid W in container 2 causing the liquid level of liquid W to drop relative to container 2 (a decrease in the weight of liquid W), thereby supplying liquid W to the second container 16. As a result, the liquid level in container 2 rises, maintaining the distance h at a predetermined distance. 【0033】 Next, the moisture removal method of this embodiment will be explained using Figure 6. 【0034】 First, put the solid block ice into container 2 (step S1). 【0035】 Next, the block ice in container 2 is heated to thaw it (step S2). As a result, the block ice in container 2 melts and becomes liquid W. 【0036】 Next, the container 2 containing liquid W is placed in storage unit 1 (step S3). 【0037】 Next, the liquid W in container 2 is irradiated with microwaves M (step S4). This causes the water in the liquid W to evaporate. The irradiation with microwaves M continues until the process shown in the flowchart is completed. 【0038】 Next, it is determined whether the water in the liquid W in container 2 has evaporated sufficiently (step S5). For example, it is determined whether the weight of the liquid W has decreased sufficiently (to a predetermined weight) from the initial weight before irradiation with microwave M. 【0039】 If it is determined that the water in the liquid W in container 2 has sufficiently evaporated (Step S5: YES), the process shown in the flowchart is terminated. On the other hand, if it is determined that the water in the liquid W in container 2 has not sufficiently evaporated (Step S5: NO), the distance h between the discharge unit 3A and the liquid surface is adjusted to maintain a predetermined distance (Step S6). For example, this adjustment may be made using the distance-holding mechanism of the water removal device A described in Example 1-4, or it may be adjusted by manually lifting container 2 and replacing the base 4 with a taller base 4. After completing Step S6, the process proceeds to Step S5. This allows for continuous irradiation of the liquid W with microwaves M, and by maintaining the distance h at a predetermined distance even as the water evaporates, the water in the liquid W can be efficiently removed. 【0040】 Next, using Figures 7(A) and (B), we will explain the experimental results regarding the change in weight of liquid W obtained by thawing block ice and irradiating it with microwaves M. According to these experimental results, when 10 kg of liquid W was placed in a plastic bucket and irradiated with microwaves M, approximately 5.6 kg of water was removed in 60 minutes. On the other hand, when 20 kg of liquid W was placed in an enamel container and irradiated with microwaves M, approximately 19.3 kg of water was removed in 225 minutes. 【0041】 As described above, the moisture removal device A of this embodiment includes a waveguide 3 (an example of "irradiation means") that irradiates microwaves M onto a liquid W containing moisture in a container 2, and a distance-holding mechanism (an example of "distance-holding means") that maintains the distance h between the surface of the liquid W in the container 2 and the emission section 3A of the waveguide 3 that emits microwaves M at a predetermined distance. 【0042】 Therefore, according to the moisture removal device A of this embodiment, when evaporating the moisture from liquid W by irradiating with microwaves M, the microwaves M can be continuously irradiated while maintaining the distance h between the microwave M emitter 3A and the liquid surface of liquid W at a predetermined distance. By setting this predetermined distance to the optimal distance for evaporation, the moisture from the liquid can be efficiently removed. 【0043】 Furthermore, the moisture removal method of this embodiment includes a step S4 (an example of an "irradiation step") in which microwaves M are irradiated onto a liquid W containing moisture in a container 2, and a step S6 (an example of a "distance holding step") in which the distance h between the surface of the liquid W in the container 2 and the emission unit 3A that emits microwaves M in step S4 is maintained at a predetermined distance. 【0044】 Therefore, according to the moisture removal method of this embodiment, when evaporating the moisture from liquid W by irradiating with microwaves M, the microwaves M can be continuously irradiated while maintaining the distance h between the microwave M emitter 3A and the liquid surface of liquid W at a predetermined distance. By setting this predetermined distance to the optimal distance for evaporation, the moisture from the liquid can be efficiently removed. 【0045】 In step S2 of Figure 6, block ice (an example of "solid") may be heated and thawed to become liquid W. Alternatively, the heating and thawing of the block ice may be performed in a separate container from container 2, the liquid W from that separate container may be transferred to container 2, and container 2 may be stored in storage unit 1. 【0046】 Furthermore, the moisture removal device A may be equipped with a heating mechanism (an example of a "heating means") that converts block ice (an example of a "solid") into liquid W by heating and thawing it. That is, the heating mechanism heats the block ice by recovering the heat of the steam discharged from the exhaust port 6 by an exhaust fan (an example of a "discharge means"). As for the method of heating the block ice, for example, heated steam may be blown directly onto the block ice, or a thawing chamber (not shown) for thawing the block ice may be prepared, the block ice may be placed inside the thawing chamber, and the block ice may be heated by heating the inside of the thawing chamber with heated steam. 【0047】 [Differentiation] Modifications of Examples 1-4 described above will now be explained. The modifications described below may be combined as appropriate. 【0048】 [Example 1] In Modification 1, a liquid level gauge is installed in the moisture removal device A to measure the height of the liquid W inside container 2, and the liquid level is measured. For example, in the moisture removal device A of Example 4, a float-type liquid level gauge or the like is installed in the second container 16 to measure the liquid level. In the moisture removal device A of Examples 1 to 3, a weighing scale is installed to measure the weight of container 2, and the liquid level is measured by the change in weight. 【0049】 [Differentiation 2] In Modification 2, the liquid W, which is thawed in step S2 of Figure 6, is preheated before irradiation with microwave M. Specifically, a preheater is provided in the moisture removal device A to preheat the liquid W, which is thawed in step S2 of Figure 6. For example, in Example 4, an IH (Induction Heating) device (an example of "preheating means") is provided to heat the liquid W in the second container 16, and a preheater (an example of "preheating means") is provided to recover the heat of the water vapor discharged from the exhaust port 6 and heat it, thereby raising the initial temperature of the liquid W with the preheater. By raising the temperature of the liquid W in this way, the water in the liquid W can be efficiently evaporated by irradiation with microwave M. Alternatively, a heater for heating the liquid W during the irradiation with microwave M may be provided in the moisture removal device A and the liquid W may be heated. [Explanation of symbols] 【0050】 1: Storage room 2: Container 3: Waveguide 3A: Output section 4: Base 5: Air supply port 6: Exhaust vent 11: Spring base 11A: Spring 11B: Mounting plate 12: Float 13: Wire 14: Jack 15: Mounting platform 16:Second container 17: tube 18: Supply section A: Moisture removal equipment S: Water vapor W:Liquid h :distance

Claims

[Claim 1] An irradiation means for irradiating a liquid containing water in a container with microwaves, Distance-holding means for maintaining a predetermined distance between the surface of the liquid contained in the container and the emission part of the irradiation means that emits the microwaves, Equipped with, The distance-maintaining means is a float provided in the ejection section that floats on the liquid, The water removal device is characterized in that the float is sized such that when it floats on the liquid, the distance between the surface of the liquid and the discharge part is the predetermined distance. [Claim 2] A heating means that turns a solid into a liquid by heating and thawing it, An irradiation means for irradiating the liquid containing water in a container with microwaves, Distance-holding means for maintaining a predetermined distance between the surface of the liquid contained in the container and the emission part of the irradiation means that emits the microwaves, A storage unit for storing the aforementioned container, A discharge means for discharging water vapor from the storage compartment, Equipped with, The moisture removal device is characterized in that the heating means heats using the heat of the steam discharged by the discharge means. [Claim 3] A moisture removal device according to claim 1, A storage unit for storing the aforementioned container, A discharge means for discharging water vapor from the storage compartment, A moisture removal device characterized by comprising the following features. [Claim 4] A moisture removal device according to any one of claims 1 to 3, A moisture removal device characterized in that the irradiation means further comprises a preheating means for heating the liquid before the microwave is irradiated. [Claim 5] An irradiation step of irradiating a liquid containing water in a container with microwaves, The process includes a distance-holding step of maintaining a predetermined distance between the surface of the liquid contained in the container and the emission unit that emits the microwaves in the irradiation step, In the distance maintenance step, A float having a size such that the distance between the surface of the liquid and the ejection part is the predetermined distance when floated on the liquid is placed on the surface of the liquid. A method for removing moisture, characterized in that the discharge part descends in accordance with the descent of the float, thereby maintaining the distance between the surface of the liquid and the discharge part at the predetermined distance. [Claim 6] A heating step of heating a solid to thaw it and turn it into a liquid, An irradiation step of irradiating the liquid containing water in a container with microwaves, A distance-holding step of maintaining a predetermined distance between the surface of the liquid contained in the container and the emission unit that emits the microwaves in the irradiation step, Includes, A method for removing moisture, characterized in that the heating step involves heating using the heat of steam discharged from a storage compartment that houses the container.

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