Snow melting device

Abstract

To provide an efficient snow-melting apparatus using a heater.SOLUTION: A snow-melting apparatus has a casing in which an inner cavity is formed on one surface, and a heater installed on the inner cavity. The casing has one surface open to allow an infrared emission from the heater to pass through. The peak wavelength of the irradiation energy distribution of the infrared emission is 1.4 to 1.5 μm. As a result, the liquid phase (water) of the snow is heated efficiently.SELECTED DRAWING: Figure 3C

Description

Technical Field

[0001] The present invention relates to a snow melting device.

Background Art

[0002] In snowy regions, snow causes obstacles such as a load on buildings and an obstacle hindering traffic. As a process for removing this obstacle, there are snow removal, snow clearance, snow melting, etc. Snow removal and snow clearance are processes of moving snow while keeping it solid. On the other hand, snow melting is a process of melting snow into water and then treating it in the same way as rain.

[0003] The snow removed and cleared on the road becomes an obstacle to pedestrians. On narrow sidewalks, it is difficult to perform mechanical snow removal because of signs, billboards, and exclusive possessions, and there is a problem of a shortage of manpower for timely snow removal during the snowy season.

[0004] Conventionally, a watering facility installed on the road surface of a paved road or a road heating facility buried in a paved road has also been widely adopted. However, the watering facility and the road heating facility involve a great deal of labor and cost for auxiliary work on the paved road. The repair work also involves a great deal of labor and cost.

[0005] Therefore, there is an increasing interest in an infrared snow melting device that melts snow and has the following advantages. (1) No manual labor such as mechanical snow removal is required. (2) The restrictions on the installation location can be relaxed. That is, it can be installed in the form of a lighting fixture at a position away from the paved road. (3) Construction and maintenance management are easy.

[0006] As an infrared snow melting device, snow melting appliances that utilize heaters have conventionally existed and are also commercially sold on the market. In Patent Document 1 below, it is stated that, "In the present invention, it is preferable to set the peak wavelength of the light output from the heater 4 to be about 1.0 μm to 1.3 μm.... On the other hand, when the peak wavelength becomes longer than 1.3 μm, it is easily absorbed by the air and the intended effect cannot be obtained." (Paragraph 0013), which negates the peak wavelength of the snow melting appliance according to the present invention.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] When the inventors obtained and investigated snow melting appliances that utilize heaters, their characteristics were diverse. Therefore, the inventors examined the characteristics required for snow melting treatment and, based on the examination results, have been developing efficient and effective snow melting appliances. Accordingly, an object of the present invention is to provide an efficient snow melting appliance that utilizes a heater.

Means for Solving the Problems

[0009] The snow melting appliance according to the present invention has, on one side, a casing in which an internal cavity is formed and a heater installed in the internal cavity, and the casing is a snow melting appliance in which one side through which infrared light emission from the heater passes is open, and the peak wavelength of the irradiation energy distribution of the infrared light emission is 1.4 to 1.5 μm, and it is characterized by efficiently heating the liquid phase (water) of the snow accumulation.

[0010] Furthermore, in the above snow melting appliance, the peak wavelength of the infrared irradiation energy distribution may be 1.5 μm.

[0011] Furthermore, in the snow melting device, the surface of the heater through which infrared light is emitted may be covered with a metal net, and the mesh of the metal net may be formed to a size that prevents a human finger from passing through.

[0012] Furthermore, in the snow melting device, the heater may have a filament diameter of 0.334 mm, a filament length of 8463 mm, and a color temperature of 1930K.

[0013] Furthermore, in the snow melting device, the heater filament may be in the form of a double coil formed by further winding a single coil filament twice.

[0014] Furthermore, in the snow melting tool, the filament of the heater may be formed of a halogen lamp. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide an efficient snow melting device that utilizes a heater. [Brief description of the drawings]

[0016]

Figure 1

Figure 2A

Figure 2B

Figure 2C

Figure 3A

Figure 3B

Figure 3C

Figure 3D

Figure 4A

Figure 4B

Figure 4C

Figure 5A

Figure 5B

Embodiments for Carrying Out the Invention

[0017] Hereinafter, embodiments of a snow melting device using a heater according to the present invention will be described with reference to the accompanying drawings. In the drawings, the same reference numerals are given to the same components, and duplicate descriptions in the specification are omitted.

[0018] [Basic Technical Idea] The snow melting device using the heater according to the present embodiment uses a general heating heater using an existing heater. The basic technical idea of this snow melting device is to make maximum use of melting the snow on the object without wasting the irradiation energy of the heater.

[0019] Snow accumulation exists in a state where water vapor (gas phase), water (liquid phase), and snow / ice (solid phase) are mixed, although the ratio varies depending on the ambient temperature. When the ambient temperature rises above zero degrees Celsius (the melting point), the snow / ice gradually melts from the surface and changes into water, increasing the ratio of water. The air existing between the heater and the snow accumulation is basically in the gas phase.

[0020] As shown in FIG. 1, the irradiation energy 11 from the heater 10a of the snow melting device 10 is irradiated onto the snow accumulation 12 through the air 14. A part of the irradiation energy 11 is absorbed and reflected by the air 14 and becomes a loss. Similarly, a part of the irradiation energy 11 is also reflected and transmitted by the snow accumulation 12 and becomes a loss. Therefore, the inventors aimed to irradiate the irradiation energy 11 of the heater 10 efficiently onto the water part on the surface of the snow accumulation 12 while suppressing these losses. In the snow melting device according to the present embodiment, a typical example of the heater is a halogen lamp.

[0021] Specifically, As a first step, the infrared absorption rates of the irradiation energy 11 of the heater 10 with respect to the gas phase (air) 14 and the liquid phase (moisture) of the snow accumulation 12 are examined, and infrared characteristics that are not absorbed as much as possible by the air and show a high absorption rate with respect to the moisture of the snow accumulation are determined. As a second step, a heater that effectively emits infrared rays showing a high absorption rate with respect to the moisture of the snow accumulation is developed. That's what we did.

[0022] [Snow Melting Device] (Structure of the Snow Melting Device) The structure of the snow melting device 10 is formed based on a conventionally used lighting fixture. FIGS. 2A to 2C are a perspective view, a front view, and a view for explaining the heater 10a mounted at the back of the internal cavity of the snow melting device 10, respectively. As shown in the perspective view of FIG. 2A, the snow melting device 10 has a main body portion 10c that forms an internal cavity 10b and has one open side on the front side, and an arm portion 10d attached to the main body portion.

[0023] The open surface on the front side was covered with a glass plate in conventional lighting fixtures, but glass absorbs infrared rays, leading to losses. Therefore, the open surface has the glass plate removed and is covered with a metal mesh (for example, a stainless steel mesh such as SUS304) 10e. The mesh size is such that a human finger cannot pass through (for example, an opening of 12 mm × 12 mm), ensuring safety.

[0024] The inner peripheral surface of the internal cavity 10b shown in the perspective view is covered with a reflector. A heater 10a is installed at the back of the internal cavity. When the heater is lit, the infrared light emission of the heater 10a is directly or reflected by the reflector, passes through the mesh of the metal mesh 10e on the front side, and is irradiated towards the accumulated snow 12.

[0025] (Determination of heater characteristics) In the snow melting device according to this embodiment, a typical example of the heater is a halogen lamp. As a first step, the inventors investigated the infrared absorption rate of the irradiation energy 11 of the heater 10 with respect to the moisture in the atmosphere 14 and the accumulated snow 12, and determined the characteristics of infrared rays that are not absorbed as much as possible by the atmosphere and show a high absorption rate with respect to the moisture in the accumulated snow. Figures 3A to 3D are graphs using the same data, but each graph selects the data to be displayed according to the necessary explanations to make it an easy-to-understand graph. The horizontal axis is displayed as the peak wavelength of the light emission of the heater, and the left vertical axis is displayed as the irradiation energy ratio normalized with the maximum value of the infrared irradiation energy as 100%. The right vertical axis is displayed as the absorption ratio normalized with the maximum absorption rate of water as 100%.

[0026] Figure 3A is a graph showing the difference in the absorption rate of the irradiation energy of the heater in the gas phase (atmosphere) and the liquid phase (the water part of the snow). The curve of the absorption ratio of water changes sharply in height as the peak wavelength on the horizontal axis changes, and the absorption rate reaches a maximum value at three points where the peak wavelength of the heater is 1.4 μm, 1.9 μm, and 2.4 μm.

[0027] Please refer to FIG. 3B. In order to easily grasp the rapidly changing water absorption ratio curve on a graph, three elliptical high infrared absorption rate zones corresponding to the three maximum absorption rate points are defined and used instead of the water absorption ratio curve.

[0028] FIG. 3C is a graph showing the relationship between the three high absorption rate zones and the irradiation energy of the conventional heating heater and the heater according to this embodiment. The peak wavelength of the conventional heating heater is around 1.2 μm, and as the wavelength increases, the irradiation energy gradually attenuates.

[0029] Therefore, for the three high absorption rate zones, the peak wavelength of the conventional heating heater is shifted. In order to efficiently deliver the irradiation energy to the three high absorption rate zones, it is necessary to relatively increase the peak wavelength compared to the peak wavelength of the conventional heating heater. That is, the irradiation energy curve needs to cover the high absorption rate zones.

[0030] Specifically, as shown in FIG. 3C, it has been found that the heater according to this embodiment can efficiently supply irradiation energy to the three high absorption rate zones by setting the peak wavelength to 1.4 - 1.5 μm. Since the wavelength distribution (spread) of the irradiation energy of the heater does not change, the irradiation energy of the heater according to this embodiment has a distribution in which the peak wavelength of the irradiation energy curve of the conventional heating heater moves from 1.2 μm to 1.4 - 1.5 μm on the graph. [[ID=I3]]

[0031] Figure 3D is a graph showing the relationship between the absorption rate curve of the irradiation energy of the heater by the atmosphere, the irradiation energy of the heater according to this embodiment (peak wavelength 1.5 μm), and the heating heater (peak wavelength 2.6 μm) which is a reference example. The absorption ratio curve of the atmosphere shown in Figure 3D is displayed at a ratio normalized with the maximum absorption ratio of the atmosphere as 100%, so the amplitude is enlarged compared to the absorption ratio curve of the atmosphere in Figure 3A. The irradiation energy of the heater in the reference example largely covers the absorption rate curve of the atmosphere, that is, it warms the atmosphere during passage through the atmosphere and results in energy loss. In comparison, for the heater according to this embodiment, the irradiation energy ratio rapidly decreases at wavelengths of 2.5 μm or more, and therefore the energy loss due to the atmosphere is reduced.

[0032] (Verification in the laboratory) The findings obtained here, that is, the finding that it is effective for heating water by relatively lengthening the peak wavelength of the conventional heating heater (peak wavelength 1.2 μm) (specifically, 1.4 to 1.5 μm), was to be verified at the laboratory level (constant temperature bath).

[0033] The heaters used are as follows. Example 1: Heater with a peak wavelength of 1.4 μm (without coating) Example 2: Heater with a peak wavelength of 1.5 μm (without coating) Comparative Example 1: Conventional general heating heater (without coating) Comparative Example 2: Snow melting heater A (the heater is the same as Comparative Example 1, but with a ceramic-based white coating applied) Comparative Example 3: Snow melting heater B (with a carbon-containing ceramic-based black coating applied)

[0034]

Table 1

[0035] Table 1 shows the verification experiment results of the peak wavelength of infrared rays effective for the temperature rise of moisture with respect to the heater for snow melting appliances. Except for Comparative Example 3 (snow melting heater with black coating) of No. 5, the test conditions (power value, power density, change amount of room temperature during measurement) were almost the same. The amount of water temperature rise, 16.6 °C in Example 1 of the present invention, showed a higher value compared with Comparative Examples 1 and 2. The amount of 18.0 °C in Example 2 of the present invention showed a higher value compared with Comparative Examples 1, 2, and 3. Therefore, among Examples 1 and 2, the peak wavelength 1.5 of Example 2 gave the most favorable result.

[0036] Comparative Example 3 of No. 5 shows the second highest value of the amount of water temperature rise after Example 2 of the present invention. Since it is a heater manufactured by another company, its structure is different, and it shows a lower power density value compared with other heaters.

[0037] Figure 3C is a graph showing the irradiation energy distribution of the heater of Comparative Example 3. Here, when transcribing the absorption rate of the irradiation energy of the heater in the gas phase (atmosphere) shown in Figure 3 (however, the maximum value is normalized to 100%), it can be seen that the heater of Comparative Example 3 supplies a large amount of irradiation energy to the gas phase (atmosphere).

[0038] (Development of a heater effective for snow melting) As the second step, a heater that effectively emits infrared rays showing a high absorption rate in the liquid phase (water) was developed. Specifically, a heater was developed with a relatively longer peak wavelength compared with the peak wavelength of a conventional heating heater. More specifically, a heater with a peak wavelength of 1.4 to 1.5 μm was developed.

[0039] It is known that Wien's displacement law states that the wavelength of a heater is inversely proportional to the temperature. According to this displacement law, a heater with a relatively lower color temperature and a longer wavelength was realized by making the filament of a conventional heating heater (Comparative Example 1) relatively thicker in wire diameter and longer in wire length. Specifically, it is as follows.

[0040]

Table 2

[0041] Figure 4A is a cross-sectional view along the heater axis of the heater 10a of Example 2. The heater 10a has a gas composed of an inert gas and a trace amount of halogen element sealed inside a bulb 10f formed from a quartz glass tube. This heater 10a emits infrared rays that exhibit a high absorption rate in the liquid phase (water) effectively, and thus the filament 10g is different compared to a conventional heating heater (Comparative Example 1).

[0042] Figure 4B is a diagram showing that the winding form of the filament of a conventional heating heater (Comparative Example 1) is a single coil wound once.

[0043] Figure 4C is a diagram showing that the winding form of the filament of the heater of Example 2 is a double coil in which the filament of a single coil is further wound twice. In Example 2, by adopting a double coil as the winding form, a filament with a relatively thicker wire diameter and a relatively longer wire length is accommodated in the same bulb (emission tube) 10f as that of a conventional heating heater (Comparative Example 1). Thereby, the color temperature is lowered and the peak wavelength of the irradiation energy is made relatively longer. Specifically, the peak wavelength of 1.2 μm of the conventional heating heater (Comparative Example 1) is changed to 1.5 μm in Example 2.

[0044] [Advantages and Effects] An experimental verification in the field was conducted using the snow melting device according to this embodiment. An experiment was carried out simultaneously with a conventional heating heater (Comparative Example 1) using a heater with a peak wavelength of 1.4 μm (Example 1). Figure 5A is a photograph of the experimental verification situation of the snow melting device using the heater of Example 1. In contrast, Figure 5B is a photograph of the experimental verification situation of the snow melting device using a conventional heating heater (Comparative Example 1). Comparing the two, it can be confirmed that the amount of snow melted shown in Figure 5A is more than the amount of snow melted shown in Figure 5B.

[0045] [Application Example] In this embodiment, in order to effectively utilize the heating device (heater), attention is paid to the difference in infrared absorption between the air from the heating device to the snow accumulation and the water constituting the snow accumulation. In order to effectively melt the snow accumulation, the loss of infrared rays during passage through the air is suppressed, and the infrared rays are concentrated and heated on the water on the surface of the snow accumulation. Specifically, the difference in absorption between the air and water according to the peak wavelength of the infrared rays is examined, and the infrared peak wavelength effective for heating the water is determined.

[0046] Such an idea can be applied to a drying device for wet clothes or the like. By examining the difference in infrared absorption between the clothes and the moisture and determining the infrared peak wavelength effective for heating the moisture. With the same idea, a heater that concentrates and heats infrared rays on a specific object among objects in which a solid phase, a liquid phase, and a gas phase are mixed can be made.

[0047] [Summary] The embodiments of the snow melting device according to the present invention have been described above, but these are examples and do not limit the scope of the present invention. The technical scope of the present invention is defined by the description in the appended claims.

Explanation of reference numerals

[0048] 10: Snow melting device, 10a: Heater, 10b: Internal space, 10c: Main body part, 10e: Metal mesh, 12: Snow accumulation, 14: Air,

Claims

1. A snow melting device having a casing with an internal cavity and a heater installed in the internal cavity, wherein one surface of the casing through which infrared light emitted from the heater passes is open, the filament of the heater is in the form of a double coil obtained by further double winding a single coil filament, the peak wavelength of the irradiation energy distribution of the infrared light emitted from the heater is 1.5 μm, and the snow melting device is characterized in that irradiation energy is efficiently supplied to the infrared high absorption rate zone of the liquid phase (water) of the snow accumulation.

2. The snow melting device according to Claim 1, wherein the surface through which the infrared light of the heater passes is covered with a metal mesh, and the mesh of the metal mesh is formed in a size that does not allow a human finger to pass through.

3. The snow melting device according to Claim 1, wherein the heater is composed of a halogen lamp, the wire diameter of the filament of the heater is 0.334 mm, the wire length is 8463 mm, and the color temperature is 1930 K.

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