humidifier

Abstract

To provide a heating evaporation type humidifier that makes scale less likely to deposit to a humidification tray, in which scale deposits to a heater part and to which scale is fixed, and can readily clean a heater when scale deposits on the heater.SOLUTION: A humidifier includes: a high-thermal conductive cap 4 such as a metal thin plate keeping a slight distance from a heater 3; and a cylindrical cap 2 encapsulating the cap and disposed on an outside of the high-thermal conductive cap, thereby allowing scale to selectively deposit to those two components. Accordingly, the humidifier has a structure capable of removing those components upward so as to readily clean the scale.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a steam humidifier that heats water to generate water vapor. [Background technology]

[0002] In steam humidifiers, which heat water, generate steam, and humidify, the most common method is to supply water from a water supply tank to an evaporating dish and heat it with a heater or other heating device to evaporate the water and generate steam (Figure 2). In this case, tap water is used as water 5, but tap water contains metals (calcium, magnesium, etc.) in the form of sulfates and carbonates, and these salts turn into scale when it evaporates, and adhere to and accumulate on the evaporating dish and heater. To prevent this, the evaporating dish 1 and heater 3 must be washed periodically to remove the scale.

[0003] However, in conventional steam humidifiers, the evaporation dish and heater are integrated, meaning that it is not possible to remove and clean just the evaporation dish 1, making the task of removing scale time-consuming (Figure 2).

[0004] To solve this problem, proposals have been made such as those in Patent Document 1 and Patent Document 2. Patent Document 1 describes that the heat generating section and / or the evaporation section are covered with a removable water-permeable filter material such as a fiber mesh with a large internal surface area, scale is deposited on the filter material, and cleaning is performed by removing the filter material, making the work easier.

[0005] Meanwhile, Patent Document 2 discloses a configuration that makes cleaning easy to remove scale. The humidifier disclosed in Patent Document 2 uses an electromagnetic induction coil (IH coil) disposed at a position away from the heating tank to heat water supplied from a water supply tank to the heating tank. The heating tank is made of a magnetic material, and generates heat by itself due to high-frequency magnetic flux from the IH coil, heating the water in the tank. The structure is such that water evaporates as a result of heating, and scale accumulates on this magnetic tank (heater).

[0006] The tank and coil are separated by a separation wall, with the induction source located below and a magnetic material acting as a heater located above, making it easier to clean the evaporating dish. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 4-327741 [Patent Document 2] JP 2019-124383 A Summary of the Invention [Problem to be solved by the invention]

[0008] First, in the method of precipitating scale on a permeable filter material as described in Patent Document 1, the scale accumulates in the vicinity of the heater. As time passes, the water-contacting part of the heater becomes covered with scale deposits, which reduces the efficiency of heat transfer to the raw water and causes overheating damage to the heater, so scale removal (cleaning and replacement of the permeable filter material) is required frequently. In addition, the running costs of the permeable filter material cannot be ignored, and there is a concern that replacement will take time. Furthermore, if not used, there is also the problem that mold is likely to appear. As such, there are problems in terms of cost, hygiene, ease of handling, etc.

[0009] On the other hand, the method of using an IH coil as described in Patent Document 2 has the drawback of being expensive due to the use of a coil. In addition, the distance between the IH coil and the heater is correlated with so-called efficiency, and since it is used for long periods of time, it is possible that the entire humidifier will heat up, and the configuration will become even more complicated, including the cooling of the drive power supply unit.

[0010] In addition, if pure water is used instead of tap water as a method other than those described in References 1 and 2, it is expected that scaling will not occur because it does not contain any elements that cause scaling. However, this method also requires pure water, which incurs running costs, and there are concerns about the growth of organic stains such as slime and mold during downtime in addition to scaling, so the environment in which it can be used is limited. [Means for solving the problem]

[0011] In order to solve the above problems, we propose a method characterized by the arrangement of a thermally conductive metal cap 4 that surrounds the heater, and a cylindrical cap 2 that coaxially surrounds 4. These two functional parts are structured so that they can be easily removed by simply lifting them up from above. Furthermore, the two parts are light, so that scale that adheres to these parts can be easily removed and cleaned. It has become possible to prevent scale accumulation on the water-contacting parts of the heater by depositing most of the scale on the surfaces of these two removable functional parts.

[0012] First, the main cause of scale formation is the condensation and precipitation of multiple inorganic salts dissolved in the water on the surface of the heat-generating components that are submerged in water as the raw water evaporates. Typically, the dissolved salts in the tap water used in evaporative humidifiers have a hardness of about 50 to 100, and 0.5 to 5 grams of scale will form when 1000 ml of raw water evaporates.

[0013] A humidifier with a heater power of about 200W consumes about 2 liters of raw water per day, and assum- ing that the heat transfer surface area of ​​the submerged heater components is about 25 cm2 and the specific gravity of the scale material is about 2, the average thickness of scale that precipitates on the surface of the heating element (heater) from raw water with a hardness of 100 will be 0.1 mm per day; if the scale is not removed, the efficiency of heat transfer from the heating element to the inflowing water will decrease over time, resulting in increased power consumption and a shortened heater lifespan.

[0014] Figure 2 shows the configuration of a conventional humidifier in which the heating element (heater) is directly immersed in the raw water. The mechanism by which scale forms on the surface of the heating element is that when heating begins, the surface of the heating element (heater) heats up and generates a large number of bubbles made of dissolved air and water vapor, and as the raw water in the bubble region evaporates, the dissolved inorganic salts precipitate on the surface of the heating element (heater) as initial nuclei of scale. In the water vapor generation section, raw water in an amount equivalent to the amount of water that evaporates is continuously supplied from the water supply container, so that the scale nuclei grow and enlarge over the heating time.

[0015] By installing two removable functional parts (2 and 4 in Fig. 1), the present invention suppresses the generation and growth of scale nuclei on the surface of the heating element, and shifts the site of scale adhesion and accumulation to the surfaces of the two functional parts located away from the surface of the heating element.

[0016] In FIG. 1, the metal cap 4 and the cylindrical cap 2 of the present invention are arranged coaxially, the metal cap 4 covers the water-immersed portion of the heating element 3, and the cylindrical cap 2 is attached so as to cover the metal cap 4. By inserting the metal cap 4 and the cylindrical cap 2, the raw water reservoir 5 of the steam generating section is separated into an inner volume (V1) in which the heat-generating components are immersed, a volume (V2) restricted to the inside of the cylindrical cap 2 outside the metal cap 4, and a volume (V3) between the outside of the cylindrical cap 2 and the raw water container. The water levels of V1 and V2 drop due to evaporation of the raw water, but a narrow gap of about 1 mm is provided at the bottom of the metal cap 4 and the cylindrical cap 2 as a flow path to compensate for this drop in water level. The flow resistance of this gap mitigates momentary backflow in the supply path during bumping, ensuring a stable supply of raw water.

[0017] Below, we will first explain the function of the first part, the thermally conductive metal cap 4. The metal cap 4 is made of a strip of metal with good thermal conductivity, such as Cu, with a thickness of about 0.1-1 mm, and allows the raw water that comes into direct contact with the surface of the heat-generating component 3 to flow in only from the gap between the metal cap 4 and the bottom of the container 1. The volume V1 of water surrounded by the cap 4 and heater 3 is in contact with the heater, so by setting the distance between the heater 3 and the heat-conducting metal cap 4 at 0.1 to several millimeters, the boiling water moves up and down vigorously, causing bumping, and V1 is replaced with high-temperature steam. As a result, the contact time of the raw water required for scale nuclei to form continuously on the surface of the heating element is shortened to less than one-tenth of that required at the very least, and the location is also unsteady. During bumping, the space between the heating element and the metal cap 4 is filled with high-temperature steam, and the high thermal conductivity caused by this is responsible for the transfer of heat from the heating element to the raw water. The upper part of the metal cap 4 is opened (8) so that the evaporated high-temperature steam can escape, and the high-temperature steam during bumping is quickly released. Splashing water droplets from the bumping water surface adhere to the upper water surface on the back side of the metal cap 4, but they do not stick to one place, and the droplets spread wet to both the inside and outside of 4. In this way, raw water is supplied to the upper part of the metal cap 4 by bumping from both areas V1 and V2 and by the infiltration of raw water on the wall surface of the metal cap 4. Regarding the temperature of the upper part of the metal cap 4, T0>T1>T2>T3, where T2 is higher than 100°C, assuming that the temperature of the heater 3 (T0) and the average temperature of V1 (T1), the surface temperature of the metal cap 4 exposed from the water surface is at least equal to T1. As a result, recondensation of the high-temperature steam on the upper part of 4 is suppressed, and dilution of the infiltrated boiling raw water is also prevented, so that there is no re-dissolution of scale. During this time, steam evaporation continues, so scale can be preferentially deposited on the area of ​​the metal cap 4 exposed above the water surface.

[0018] Due to the above mechanism, almost no scale forms in the area close to the heater inside the heat conductive metal cap 4. Because the metal cap 4 is made of Cu, a metal with high thermal conductivity, the temperature approaches 100°C, suppressing recondensation of high-temperature steam, while the supply of raw water from areas V1 and V2 continues, causing scale to grow preferentially on the outside of the heat conductive metal cap 4 that is exposed above the water surface.

[0019] The second part, cylindrical cap 2, is about 10 cm long, which is necessary as an airflow guide to guide high-temperature steam from raw water reservoirs V1 and V2 into the air, and is made of plastic with moderate heat retention. When the high-temperature steam leaves the gap (8) above cylindrical cap 2, the outside of cylindrical cap 2 is exposed to the outside air temperature, and as the high-temperature steam diffuses upward, it comes into contact with the inner wall of cylindrical cap 2, and some of it recondenses and flows back to V2. As a result, the recondensed water flows down in the part of the inner wall of cylindrical cap 2 that is above the water, preventing the infiltration of raw water into V2 and preventing the formation of scale. In the portion of the inner wall of the cylindrical cap 2 that is underwater, the raw water in the V2 section is diluted by the returning recondensed water 9, so the scale concentration in the raw water also decreases. In addition, because the concentration of dissolved salts in the raw water flowing into the V2 region has decreased due to the generation of scale on the outside of the cylindrical cap 2, scale generation is at a negligible level. The part of the outer surface of cylindrical cap 2 that is immersed in V3 is at the raw water inlet, so there is no temperature difference that would cause precipitation of dissolved substances, and the amount of scale is negligible, just like the inner surface of cylindrical cap 2. Meanwhile, in the boundary area of ​​this outer surface of cylindrical cap 2 that is exposed to the air from the water surface of V3, scale nuclei form due to evaporation of the gas-liquid boundary where the raw water comes into contact. This initially occurs preferentially near the water surface, but over time it gradually infiltrates and covers almost the entire surface of the outer surface of V2 that is exposed to the air. This occurs when the heat of condensation from the high-temperature steam condenses on the inner wall of the cylindrical cap 2 is used to evaporate the raw water that has infiltrated the outer surface of the cylindrical cap 2, resulting in the precipitation of dissolved substances at that site. The surface of the cylindrical cap 2 covered with this scale develops fine flake-like irregularities, resulting in an extremely large evaporation surface area. As a result, the amount of scale generated is nearly one order of magnitude more efficient than with the thermally conductive metal cap 4, and scale growth continues. The bumping of V1 causes The inflow of raw water into the heating element is suppressed, and the amount of evaporation from V2 increases. The amount of heat Q2 passing through member 2 increases, and the number of scale nuclei increases in the water-saving parts of the exterior wall. In addition, by coating the outer surface of the cylindrical cap 2 with a hydrophilic treatment or a film that is easily penetrated, the infiltration of raw water at the initial stage of scale nucleation in V3 can be initiated quickly, thereby shortening the time until a scale coating is formed on the outer surface of 2. Effect of the Invention

[0020] The steam humidifier of the present invention has suitable parts 2, 4 arranged around the heater, making it easier for scale to adhere selectively to these parts. As scale buildup on the heater's water-contacting parts can be ignored, long-term continuous operation is possible. In addition, because these parts are easy to remove, scale removal and cleaning can be easily performed in a short time, for example by washing the entire parts. [Brief description of the drawings]

[0021] [Figure 1] 2 is a steam generating section of the steam humidifier of the present invention. [Diagram 2] Conventional steam humidifier. [Diagram 3] The steam humidifier of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The steam humidifier has a structure in which scale formation is controlled at a specific location, making it easy to clean. EXAMPLES

[0023] Figure 1 shows the steam generation section of a steam type humidifier according to the present invention. There is a heater 3 fixed to an evaporating dish 1, and the submerged portion of this heater 3 has a small gap between it and a thermally conductive metal cap 4. This gap is closest to the heater, and although water is supplied from the bottom of the thermally conductive metal cap 4, the water is always at a high temperature and is in a state of bumping, filling the gap with high-temperature steam, suppressing the formation of scale. Scale formation due to infiltration of bumping splashes and droplets is concentrated in the part of the thermally conductive cap above the water surface.

[0024] The cylindrical cap 2 has almost no scale on either the inner or outer walls of the submerged portion, but above the water surface, scale accumulates only on the outer wall due to evaporation of the infiltrating raw water. Also, almost no scale forms on the inner wall due to the downward flow of re-condensed water. [Industrial Applicability]

[0025] Steam generators with a structure in which the heat source for generating steam is directly immersed in water are used in humidifiers and other industrial products that use steam as a heat source, but dealing with the scale that forms on the heat source is an issue. The present invention uses a component that is easy to remove and maintain for the heat source, and causes scale to form preferentially on its surface, thereby suppressing the formation of scale on the surface of the heat source. [Explanation of symbols]

[0026] 1 Evaporation dish 2 Cylindrical Cap 3. Heater 4 Thermally conductive metal cap 5 water 6. Water tank 7 Scale 8. Water Vapor 9 Recondensed water 10 Bottom gap 11 Evaporation surface 12 Water supply valve 13. Water vapor escape hole T0 Heater center temperature T1 Heater envelope temperature T2 Average temperature of raw water in vessel C T3 Steam release surface temperature T4 Recondensed water temperature Q2 Heat dissipation from the recondensation section

Claims

1. A steam type humidifier comprising an evaporating dish for storing raw water and a direct immersion heat source heater, which generates water vapor by heating the raw water, further comprising a detachable cylindrical highly thermally conductive metal cap which maintains a small gap with the outer edge of the heat source heater, and a cylindrical cap which surrounds the outer edge of the highly thermally conductive metal cap, the highly thermally conductive metal cap and the cylindrical cap having holes through which water vapor can escape, and the raw water flows in through the gap between the highly thermally conductive metal cap and the bottom of the evaporating dish, and when bumping occurs, the space between the heat source heater and the highly thermally conductive metal cap is filled with high temperature water vapor.

2. A steam humidifier, wherein the cylindrical cap as recited in claim 1 has an outer surface which is hydrophilic and / or roughened.

3. The steam humidifier according to claim 1, The cylindrical cap that encases this on the outside of the high thermal conductivity metal cap is A steam humidifier is characterized by having holes that allow water vapor to escape.

4. The steam humidifier according to claim 1, The highly thermally conductive cap is fixed to the heater at a small distance. A steam humidifier is characterized by having holes that allow water vapor to escape.

5. A steam humidifier according to claim 1, wherein the cylindrical cap has an outer surface which is hydrophilic and / or roughened.

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