Liquid treatment apparatus

Abstract

To provide a liquid treatment apparatus capable of improving liquid tightness with a simple configuration.SOLUTION: A liquid treatment apparatus irradiates a liquid to be treated with ultraviolet light. The liquid treatment apparatus has: a case having a first recess opening at one end and a second recess opening at the bottom of the first recess; a light source provided inside the second recess and having a light emitting element capable of irradiating the ultraviolet rays; a window which is plate-shaped and provided near the opening of the first recess, through which the ultraviolet rays irradiated from the light emitting element can pass; and a sealing member provided between the side surface of the first recess and the side surface of the window, and adhered to the side surface of the first recess and the side surface of the window by elastic force.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE Embodiments of the present invention relate to a liquid treatment device. [Background technology]

[0002] There are liquid treatment devices that irradiate liquids such as water with ultraviolet light to sterilize the liquid or remove organic matter contained in the liquid. Discharge lamps that irradiate ultraviolet light have been used as light sources for liquid treatment devices, but light emitting devices such as light emitting diodes that irradiate ultraviolet light have begun to be used from the viewpoints of energy saving and long life.

[0003] Such a liquid treatment device includes a case, a light-emitting element provided in the internal space of the case for irradiating ultraviolet light, and a window provided at an opening of the internal space of the case, and the gap between the window and the case is sealed to prevent the liquid from contacting the light-emitting element provided in the internal space of the case.

[0004] For example, an adhesive or sealant may be applied between the window and the case to seal the gap between them, but this can have problems such as time-consuming work, variations in the amount of application resulting in variations in liquid-tightness, and difficulty in disassembly, resulting in reduced maintainability.

[0005] In some cases, a seal member is provided between the window and the case to seal the gap between the window and the case. However, simply providing a seal member may cause variations in the crush rate of the seal member, which may allow liquid to seep into the internal space of the case. In this case, providing a mechanism for controlling the crush rate of the seal member in the case may complicate the configuration of the liquid treatment device, which may lead to an increase in size and cost of the liquid treatment device. Therefore, there has been a demand for the development of a liquid treatment device that has a simple configuration and can improve liquid-tightness. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2021-041382 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a liquid treatment device that has a simple configuration and is capable of improving liquid-tightness. [Means for solving the problem]

[0008] A liquid treatment device according to an embodiment irradiates ultraviolet light to a liquid to be treated. The liquid treatment device includes a case having a first recess opening at one end and a second recess opening at a bottom surface of the first recess; a light source provided inside the second recess and having a light emitting element capable of irradiating the ultraviolet light; a plate-shaped window provided near the opening of the first recess and capable of transmitting the ultraviolet light irradiated from the light emitting element; and a seal member provided between a side surface of the first recess and a side surface of the window and adapted to come into close contact with the side surface of the first recess and the side surface of the window by elastic force. Effect of the Invention

[0009] According to an embodiment of the present invention, it is possible to provide a liquid treatment device that can improve liquid-tightness with a simple configuration. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic perspective view illustrating a liquid treatment apparatus according to an embodiment of the present invention; [Diagram 2] 2 is a schematic cross-sectional view of the liquid treatment device in FIG. 1 taken along line AA. [Diagram 3] 10A and 10B are schematic cross-sectional views illustrating a liquid treatment device including a sealing member according to a comparative example. [Figure 4]13 is a schematic cross-sectional view illustrating a liquid treatment device including a seal member according to another comparative example. FIG. [Diagram 5] 5A to 5C are schematic cross-sectional views illustrating a sealing member. [Figure 6] 11A and 11B are schematic cross-sectional views illustrating liquid treatment devices according to other embodiments. [Figure 7] FIG. 7 is a schematic enlarged view of part C in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and detailed description thereof will be omitted as appropriate.

[0012] FIG. 1 is a schematic perspective view illustrating a liquid treatment device 1 according to the present embodiment. FIG. 2 is a schematic cross-sectional view of the liquid treatment device 1 in FIG. 1 taken along the line AA. A liquid treatment device 1 according to this embodiment irradiates a liquid to be treated with ultraviolet light. The liquid treatment device 1 may be immersed in the liquid, or may be provided at a position separated from the liquid. As shown in FIGS. 1 and 2, a liquid treatment device 1 includes, for example, a case 2, a light source 3, a window 4, a connector 5, and a sealing member 6.

[0013] The case 2 has a columnar shape. The case 2 has, for example, a cylindrical shape. However, the shape of the case 2 is not limited to a cylindrical shape. The case 2 can have any shape, such as a rectangular column. However, when the case 2 is immersed in the liquid to be treated, it is preferable that the outline of the case 2 is a shape composed of curves such as a circle or an ellipse when viewed from a direction along the central axis 1a of the liquid treatment device 1. By forming the case 2 in this way, it is possible to suppress the occurrence of turbulence in the flow of the liquid when the case 2 is immersed in the liquid to be treated. In addition, even if the case 2 collides with the inner wall of the flow path, it is possible to suppress the inner wall of the flow path from being damaged, and the case 2 from being chipped or cracked. In this case, as shown in FIG. 1, if the case 2 has a cylindrical shape, it is easy to manufacture the case 2.

[0014] The case 2 has, for example, a recess 2a (corresponding to an example of a first recess), a recess 2b (corresponding to an example of a second recess), a recess 2c, and a hole 2d. The recess 2a is open at one end of the case 2. A window 4 and a seal member 6 are housed inside the recess 2a. The recess 2b opens to the bottom surface of the recess 2a. The light source 3 is housed inside the recess 2b. This makes it possible to prevent external forces from being applied to the light source 3. In addition, as will be described later, the case 2 cooperates with the window 4 and the seal member 6 to prevent liquid from coming into contact with the light source 3.

[0015] The recess 2c opens to the other end of the case 2. The connector 5 is housed inside the recess 2c. In this case, the recess 2c can be omitted. By omitting the recess 2c, the length of the liquid treatment device 1 in the direction of the central axis 1a can be shortened. In addition, the weight of the liquid treatment device 1 can be reduced. On the other hand, if the recess 2c is provided, it is possible to prevent external forces, etc. from being applied to the connector 5. Therefore, the waterproofness of the connector 5 can be maintained and damage to the connector 5 can be suppressed.

[0016] The hole 2d penetrates between the bottom surface of the recess 2b and the bottom surface of the recess 2c. A wire 5c that electrically connects the light source 3 and the connector 5 is provided in the hole 2d.

[0017] The dimensions of the case 2 can be appropriately changed depending on the size of the light source 3, the application of the liquid treatment device 1, and the like.

[0018] As described above, the light source 3 is housed inside the recess 2b. Therefore, ultraviolet light emitted from the light source 3 is incident on the inner wall of the recess 2b. Furthermore, the liquid treatment device 1 (case 2) may be immersed in the liquid to be treated, or the liquid may adhere to the outer wall of the case 2. Furthermore, an external force may be applied to the liquid treatment device 1 (case 2).

[0019] Therefore, it is preferable that the material of the case 2 has resistance to the ultraviolet rays irradiated from the light source 3, resistance to the liquid to be treated, and resistance to external forces. For example, the material of the case 2 can be a metal such as stainless steel or a ceramic such as steatite. In this case, if the material of the case 2 is white ceramic, the ultraviolet rays incident on the inner wall of the recess 2b are easily reflected. Therefore, the utilization efficiency of the ultraviolet rays irradiated from the light source 3 can be improved.

[0020] The light source 3 can be provided inside the recess 2b. The light source 3 can be provided, for example, on the bottom surface of the recess 2b. The light source 3 includes, for example, a light emitting element 3a and a substrate 3b. The light-emitting element 3a is provided on the surface of the substrate 3b opposite to the bottom surface side of the recess 2b. The light-emitting element 3a irradiates ultraviolet light toward the window 4. At least one light-emitting element 3a can be provided. The light source 3 illustrated in FIG. 1 and FIG. 2 is provided with one light-emitting element 3a. When multiple light-emitting elements 3a are provided, the multiple light-emitting elements 3a can be connected in series. There is no particular limitation on the light-emitting element 3a as long as it is an element capable of irradiating ultraviolet light. The light-emitting element 3a can be, for example, a light-emitting diode or a laser diode.

[0021] The light emitting element 3a can be, for example, a surface mount type light emitting element or a bullet type light emitting element having a lead wire. The light emitting element 3a can also be, for example, a chip type light emitting element. The chip type light emitting element 3a can be mounted on the wiring pattern of the substrate 3b by COB (Chip On Board). The light emitting element 3a illustrated in FIG. 1 and FIG. 2 is a surface mount type light emitting element.

[0022] The peak wavelength of the ultraviolet light emitted from the light-emitting element 3a is not particularly limited as long as it can kill bacteria contained in the liquid, inactivate viruses, decompose organic matter, etc. However, if the light-emitting element 3a is capable of emitting ultraviolet light with a peak wavelength of 200 nm to 280 nm, it can effectively kill bacteria and inactivate viruses.

[0023] The substrate 3b is plate-shaped and is provided on the bottom surface of the recess 2b. For example, the substrate 3b can be detachably attached to the bottom surface of the recess 2b using a fastening member such as a screw. In this way, the maintenance of the light source 3 becomes easy. In this case, a layer made of thermally conductive grease (heat dissipating grease) can be provided between the substrate 3b and the bottom surface of the recess 2b. If a layer made of thermally conductive grease is provided, it is possible to prevent a gap from being generated between the substrate 3b and the bottom surface of the recess 2b. Therefore, the heat generated in the light emitting element 3a is easily transferred to the case 2, and it is possible to prevent the temperature of the light emitting element 3a from exceeding the maximum junction temperature.

[0024] Also, for example, the substrate 3b can be bonded to the bottom surface of the recess 2b using an adhesive or double-sided tape. In this case, the adhesive is preferably an adhesive with high thermal conductivity. For example, the adhesive can be an adhesive mixed with a filler using an inorganic material such as aluminum oxide. If the substrate 3b is bonded to the bottom surface of the recess 2b, it is possible to prevent a gap from being generated between the substrate 3b and the bottom surface of the recess 2b. Therefore, it is easy to prevent the temperature of the light-emitting element 3a from exceeding the maximum junction temperature. In addition, since the configuration of the liquid treatment device 1 is simplified, it is possible to reduce the manufacturing cost.

[0025] A wiring pattern can be provided on the surface of the substrate 3b opposite to the bottom surface side of the recess 2b. The light emitting element 3a can be electrically connected to the wiring pattern.

[0026] The material of the substrate 3b is preferably resistant to the ultraviolet light irradiated from the light emitting element 3a. The material of the substrate 3b may be, for example, ceramics such as aluminum oxide. The substrate 3b may also be a metal core substrate in which the surface of a metal plate is covered with an inorganic material.

[0027] In this case, since ceramics and metal core substrates have high thermal conductivity, forming the substrate 3b using these materials facilitates the transfer of heat generated in the light-emitting element 3a to the case 2. Therefore, the temperature of the light-emitting element 3a can be effectively prevented from exceeding the maximum junction temperature.

[0028] The window 4 is plate-shaped and is provided in the case 2 near the opening of the recess 2a. The window 4 covers the opening of the recess 2b. The window 4 faces the light-emitting element 3a. The window 4 is made of a material that can transmit ultraviolet light irradiated from the light-emitting element 3a and is resistant to ultraviolet light and the liquid used for processing. The window 4 is made of, for example, quartz glass or a fluororesin that transmits ultraviolet light.

[0029] An anti-reflection film may be provided on the surface of the window 4 facing the light-emitting element 3a. If an anti-reflection film is provided, it is possible to prevent the ultraviolet light irradiated from the light-emitting element 3a from being reflected by the window 4, making it difficult for the ultraviolet light to be irradiated to the liquid to be treated. In other words, it is possible to improve the efficiency of use of the ultraviolet light irradiated from the light-emitting element 3a.

[0030] An anti-soiling film may be provided on the surface of the window 4 opposite to the light-emitting element 3a side. For example, the liquid treatment device 1 may be used to treat seawater, groundwater, etc. In this case, seawater, groundwater, etc. contain foreign matter such as sand, dead microorganisms, and inorganic salts, and the foreign matter may adhere to the surface of the window 4 opposite to the light-emitting element 3a side. If the foreign matter adheres to the surface of the window 4, the ultraviolet light irradiated from the light-emitting element 3a is less likely to pass through the window 4, which may inhibit the sterilization of bacteria contained in the liquid, the inactivation of viruses, and the decomposition of organic matter. If an anti-soiling film is provided on the surface of the window 4, it is possible to inhibit the adhesion of foreign matter to the surface of the window 4, so that the amount of ultraviolet light irradiated to the liquid to be treated can be maintained for a long time and the number of maintenance operations can be reduced.

[0031] The connector 5 is provided on the bottom surface of the recess 2c of the case 2. In this case, the connector 5 can also be provided on the outer surface of the case 2 or on the end of the case 2 where the recess 2c opens. However, as described above, if the connector 5 is provided on the bottom surface of the recess 2c of the case 2, it is easier to protect the connector 5 from external forces and the like.

[0032] The connector 5 may be immersed in the liquid to be treated. The liquid to be treated may adhere to the connector 5. Therefore, the connector 5 may be a so-called waterproof connector. The connector 5 may be, for example, a connector conforming to IP68 as specified in JIS C 0920.

[0033] The connector 5 includes, for example, a plug 5a and a socket 5b. The plug 5a can be provided liquid-tightly in a hole 2d that opens into the bottom surface of the recess 2c of the case 2. A terminal provided inside the plug 5a is electrically connected to the wiring pattern provided on the substrate 3b, and further to the light-emitting element 3a, via a wire 5c extending inside the hole 2d.

[0034] The socket 5b is detachably connected to the end of the plug 5a opposite to the case 2. When the socket 5b and the plug 5a are connected, the space between the socket 5b and the plug 5a is sealed liquid-tight, and a terminal provided inside the socket 5b and a terminal provided inside the plug 5a are electrically connected. The terminal provided inside the socket 5b is electrically connected to a lighting circuit or the like provided outside the liquid treatment device 1 via a wire 5d.

[0035] If the connector 5 is provided, it becomes easy to connect and disconnect the wiring 5d to and from the case 2 in which the light source 3, the window 4, and the sealing member 6 are provided, and therefore it is possible to improve the ease of maintenance.

[0036] Here, the liquid treatment device 1 is used, for example, to sterilize a liquid or remove organic matter contained in the liquid, and is therefore immersed in the liquid or placed near the liquid. In this case, if the liquid penetrates into the inside of the case 2, the penetrating liquid may come into contact with the light emitting element 3a, etc., and cause the liquid treatment device to break down. For this reason, the liquid treatment device 1 is provided with a seal member 6.

[0037] First, the sealing members 16 and 26 according to the comparative example will be described. FIG. 3 is a schematic cross-sectional view illustrating a liquid treatment device 10 including a seal member 16 according to a comparative example. As shown in FIG. 3, the liquid treatment device 10 has a case 12 , a light source 3 , a window 4 , a connector 5 , and a sealing member 16 .

[0038] A recess 12a is provided in the case 12. The recess 12a opens at one end of the case 12. The light source 3 is housed inside the recess 12a. The window 4 closes the opening of the recess 12a in the case 12.

[0039] Also, a groove 12b is provided at the end of the case 12 on the side where the recess 12a is open. The groove 12b opens at the end of the case 12. The groove 12b surrounds the opening of the recess 12a. A silicone adhesive is filled inside the groove 12b. When the silicone adhesive hardens, the window 4 is bonded to the case 12 so as to be liquid-tight. When the silicone adhesive hardens, a seal member 16 is formed between the window 4 and the case 12. In this manner, the gap between the window 4 and the case 12 can be sealed.

[0040] However, doing so leads to problems such as the silicone adhesive taking a long time to fill and harden, variations in the amount filled resulting in inconsistent liquid-tightness, and difficulty in disassembling the window 4 and the case 12, reducing maintainability.

[0041] Also, instead of the silicone adhesive, a sealing member such as an O-ring can be provided inside the groove 12b. However, doing so requires a mechanism for pressing the surface of the window 4 on the light source 3 side against the sealing member. In this case, if the compression rate of the sealing member varies, liquid may seep into the inside of the recess 12a of the case 12. In this specification, the compression rate can be expressed as "(compression amount (compressed dimension) / original dimension) x 100%".

[0042] Therefore, the mechanism for pressing the surface of window 4 facing light source 3 against the sealing member needs to have a function for adjusting the squeezing rate of the sealing member as shown in Fig. 4 described later, which will result in a complicated configuration of liquid treatment device 10, and ultimately an increase in size and cost of liquid treatment device 10.

[0043] FIG. 4 is a schematic cross-sectional view illustrating a liquid processing device 11 including a seal member 26 according to another comparative example. As shown in FIG. 4, the liquid treatment device 11 has a case 22, a light source 3, a window 4, a connector 5, and a sealing member .

[0044] The case 22 has a base 22a and a lid 22b. The base 22a has a cylindrical shape and is provided with a male screw on the side surface. A recess is provided at one end of the base 22a, and the light source 3 is provided inside the recess. The lid 22b is provided on the side of the base 22a where the light source 3 is provided. The lid 22b has a recess that opens at one end. An internal thread is provided on the inner wall of the recess of the lid 22b to be screwed into the external thread on the side of the base 22a. Also, a hole is provided that penetrates between the bottom surface of the recess of the lid 22b and the other end of the lid 22b.

[0045] The seal member 26 has an annular shape and is made of an elastic material such as rubber. When the lid 22b is attached to the base 22a, the window 4 and the seal member 26 are provided between the bottom surface of the recess of the lid 22b and the end of the base 22a. In this case, the window 4 contacts the bottom surface of the recess of the lid 22b, and the seal member 26 is sandwiched between the window 4 and the end of the base 22a. Ultraviolet light emitted from light source 3 is irradiated onto the liquid to be treated through a recess provided in lid 22b, window 4, and a hole provided in lid 22b.

[0046] Here, as described above, if the compression rate of the seal member 26 is not within an appropriate range, liquid will seep into the inside of the recess of the lid 22b. The case 22 is provided with the base 22a having a male thread and the lid 22b having a female thread, so that the base 22a and the lid 22b form a mechanism for pressing the surface of the window 4 on the light source 3 side against the seal member 26.

[0047] In this case, by rotating the lid 22b, it is possible to adjust the distance between the window 4 and the end of the base 22a, and therefore the crushing rate of the seal member 26. However, providing a mechanism for pressing the window 4 against the seal member 26 would complicate the configuration of the liquid treatment device 11, leading to an increase in size and cost of the liquid treatment device 11. In addition, it would become necessary to manage the crushing rate of the seal member 26 and provide a mechanism to prevent the lid 22b from loosening.

[0048] Next, the seal member 6 according to the present embodiment will be illustrated. FIG. 5 is a schematic cross-sectional view illustrating the seal member 6. As shown in FIG. FIG. 5 is a schematic enlarged view of part B in FIG. 2 and 5, the seal member 6 has, for example, an annular shape and is provided inside the recess 2a that opens at one end of the case 2. The outer surface of the seal member 6 contacts the side surface of the recess 2a. The end of the seal member 6 on the bottom side of the recess 2a can contact the bottom surface of the recess 2a. The inner surface of the seal member 6 contacts the side surface of the window 4.

[0049] In a direction perpendicular to the central axis 1a of the liquid processing device 1, the inner dimension L1 of the seal member 6 is smaller than the dimension L2 of the window 4. The difference L3 between the dimension L2 of the window 4 and the inner dimension L1 of the seal member 6 is the compression allowance (compressed dimension). The difference between the outer dimension of the seal member 6 before the seal member 6 is provided inside the recess 2a and the inner dimension of the seal member 6 is the "original dimension" in the above-mentioned equation for the compression ratio.

[0050] The sealing member 6 can be made of an elastic material such as rubber. In this case, it is preferable to form the sealing member 6 from an elastic material that is highly resistant to ultraviolet rays, considering that the ultraviolet rays irradiated from the light-emitting element 3a are incident on the sealing member 6. The sealing member 6 can be made of, for example, fluororubber.

[0051] When attaching the window 4 to the case 2, a seal member 6 is provided inside the recess 2a, and the window 4 is pressed into the seal member 6. When the window 4 is pressed into the seal member 6, the surface of the window 4 facing the light source 3 comes into contact with the bottom surface of the recess 2a. Therefore, the position of the window 4 in the direction along the central axis 1a of the liquid treatment device 1 can be determined.

[0052] Furthermore, when the window 4 is pressed into the inside of the sealing member 6, an elastic force is generated in the sealing member 6. Therefore, the sealing member 6 comes into close contact with the side surface of the recess 2a, the bottom surface of the recess 2a, and the side surface of the window 4. If the sealing member 6 comes into close contact with these, it is possible to prevent liquid from entering the inside of the recess 2b that opens into the bottom surface of the recess 2a. As described above, since the light source 3 is housed inside the recess 2b, if it is possible to prevent liquid from entering the inside of the recess 2b, it is possible to prevent the light source 3 from breaking down. That is, the seal member 6 is provided between the side surface of the recess 6a and the side surface of the window 4, and is in close contact with the side surface of the recess 6a and the side surface of the window 4 due to elastic force.

[0053] The adhesion between the sealing member 6 and these can be controlled by the crushing ratio. The crushing ratio can be controlled by the inner dimension L1 of the sealing member 6, the outer dimension of the sealing member 6, the dimension L2 of the window 4, and the dimension of the side of the recess 2a in the direction perpendicular to the central axis 1a of the liquid processing device 1. In this case, the outer dimension of the sealing member 6 may be the same as or slightly larger than the dimension of the side of the recess 2a.

[0054] In this case, if the crushing ratio is too large, it becomes difficult to push the window 4 inside the seal member 6. If the crushing ratio is too small, liquid will easily penetrate into the inside of the recess 2b. According to the knowledge obtained by the present inventors, it is preferable that the crushing ratio of the seal member 6 between the side surface of the recess 2a and the side surface of the window 4 is 13% or more and 27% or less. In this way, it becomes easier to push the window 4 inside the seal member 6, and it is possible to prevent liquid from penetrating into the inside of the recess 2b.

[0055] As described above, when such a seal member 6 is provided, there is no need to provide a mechanism for pressing the window 4 against the seal member 26 as in the above-described liquid treatment device 11. Therefore, the configuration of the liquid treatment device 1 can be simplified.

[0056] Moreover, by generating an elastic force in the seal member 6, the seal member 6 and the window 4 can be held in the case 2. This further simplifies the configuration of the liquid treatment device 1. If the liquid treatment device 1 is subject to vibration, a plate or the like that prevents the window 4 from falling off may be provided as an auxiliary member near the opening of the recess 2a.

[0057] FIG. 6 is a schematic cross-sectional view illustrating a liquid treatment device 1b according to another embodiment. FIG. 6 corresponds to FIG. 2 described above. FIG. 7 is a schematic enlarged view of part C in FIG. As shown in FIG. 6, the liquid treatment device 1b includes, for example, a case 20, a light source 3, a window 4, a connector 5, and a sealing member 60.

[0058] The case 20 has a columnar shape. The case 20 has, for example, a recess 2a, a recess 2b, a recess 2c, a hole 2d, and a recess 2e (corresponding to an example of a third recess). The case 20 may be the case 2 described above further provided with a recess 2e.

[0059] The recess 2e opens to the bottom surface of the recess 2a. When viewed from a direction along the central axis 1c of the liquid processing device 1b, the recess 2e surrounds the opening of the recess 2b. When viewed from a direction along the central axis 1c of the liquid processing device 1b, the outer side surface of the recess 2e overlaps with the side surface of the recess 2a. In a direction perpendicular to the central axis 1c of the liquid processing device 1b, the distance between the inner side surface of the recess 2e and the central axis 1c is longer than the distance between the side surface of the recess 2b and the central axis 1c.

[0060] The seal member 60 has a portion 60a (corresponding to an example of a first portion) and a portion 60b (corresponding to an example of a second portion). The portion 60a and the portion 60b may be integrally formed. The material of the seal member 60 may be, for example, the same as the material of the seal member 6 described above.

[0061] The portion 60a has an annular shape and is provided between a side surface of the recess 2a and a side surface of the window 4. The portion 60a may be, for example, similar to the above-described seal member 6. That is, the seal member 60 may be the seal member 6 plus the portion 60b.

[0062] The portion 60b is annular and is provided at the end of the portion 60a on the bottom side of the recess 2a. When viewed from the direction along the central axis 1c of the liquid processing device 1b, the outer side surface of the portion 60b overlaps with the outer side surface of the portion 60a. The inner side surface of the portion 60b is located closer to the central axis 1c of the liquid processing device 1b than the inner side surface of the portion 60a. The inner side surface of the portion 60b may be in contact with the side surface of the recess 2e, or a small gap may be provided between the inner side surface of the portion 60b and the side surface of the recess 2e.

[0063] When attaching the window 4 to the case 20, the portion 60b is provided inside the recess 2e, and the portion 60a is provided inside the recess 2a. Then, the window 4 is pushed into the inside of the portion 60a. When the window 4 is pushed into the inside of the seal member 60 (portion 60a), the surface of the window 4 facing the light source 3 comes into contact with the bottom surface of the recess 2a. Therefore, the position of the window 4 in the direction along the central axis 1c of the liquid processing device 1b can be determined.

[0064] Furthermore, when the window 4 is pressed into the inside of the seal member 60 (portion 60a), an elastic force is generated in the seal member 60. Therefore, the seal member 60 comes into close contact with the side surface of the recess 2a, the outer side surface of the recess 2e, the bottom surface of the recess 2e, the inner side surface of the recess 2e, the side surface of the window 4, and the surface of the window 4 facing the light source 3. If the seal member 60 comes into close contact with these, it is possible to prevent liquid from entering the inside of the recess 2b that opens into the bottom surface of the recess 2a. Therefore, it is possible to prevent the light source 3 from breaking down.

[0065] Also, similar to the above-described seal member 6, the adhesion between the seal member 60 and these can be controlled by the crushing ratio. The crushing ratio can be the same as that of the above-described seal member 6. For example, the crushing ratio of the seal member 60 between the side surface of the recess 2a and the side surface of the window 4 may be set to 13% or more and 27% or less. In this way, the operation of pushing the window 4 into the inside of the seal member 60 becomes easier, and the infiltration of liquid into the inside of the recess 2b can be suppressed.

[0066] When the seal member 60 is provided, the same effect as when the seal member 6 is provided can be obtained. That is, the configuration of the liquid treatment device 1b can be simplified. Furthermore, when the portion 60b is provided, the rigidity of the seal member 60 becomes greater than the rigidity of the seal member 6. Therefore, for example, when the seal member 60 is attached to the inside of the recess 2a or the inside of the recess 2e, or when the seal member 60 is removed from the inside of the recess 2a or the inside of the recess 2e, it is possible to suppress the occurrence of twisting or the like in the seal member 60. Therefore, the work of attaching and removing the seal member 60 becomes easier. Furthermore, if the portion 60b is provided, the path through which liquid can penetrate becomes longer, which can further suppress the penetration of liquid.

[0067] Although some embodiments of the present invention have been illustrated above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, etc. can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims. In addition, the above-mentioned embodiments can be implemented in combination with each other. [Explanation of symbols]

[0068] 1 liquid treatment device, 1a central axis, 1b liquid treatment device, 1c central axis, 2 case, 2a recess, 2b recess, 2e recess, 3 light source, 3a light emitting element, 3b substrate, 4 window, 6 sealing member, 20 case, 60 sealing member, 60a portion, 60b portion

Claims

1. A liquid treatment device that irradiates a liquid to be treated with ultraviolet light; a case having a first recess that opens at one end and a second recess that opens at a bottom surface of the first recess; a light source provided inside the second recess and having a light emitting element capable of irradiating the ultraviolet light; a plate-like window provided near an opening of the first recess and capable of transmitting the ultraviolet light irradiated from the light-emitting element; a seal member provided between a side surface of the first recess and a side surface of the window, the seal member being brought into close contact with the side surface of the first recess and the side surface of the window by elastic force; A liquid treatment device comprising:

2. the case further has a third recess that opens to a bottom surface of the first recess and surrounds an opening of the second recess when viewed from a direction along a central axis of the liquid treatment device; the sealing member has a first portion provided between a side surface of the first recess and a side surface of the window, and a second portion provided at an end of the first portion on a bottom surface side of the first recess, 2. The liquid treatment device according to claim 1, wherein an inner side surface of the second portion is located closer to the central axis of the liquid treatment device than an inner side surface of the first portion.

3. 3. The liquid treatment device according to claim 1, wherein a crushing ratio of the seal member between a side surface of the first recess and a side surface of the window is 13% or more and 27% or less.

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