JP5104813B2 - Ultraviolet irradiation device and total organic carbon measuring device using the same - Google Patents

Description

  The present invention provides a total organic carbon (TOC) measurement which is one application example of an ultraviolet irradiation device that irradiates ultraviolet rays onto a sample water or other measurement object with an ultraviolet lamp and an analysis device equipped with the ultraviolet irradiation device. It relates to the device.

  The ultraviolet irradiation apparatus has a built-in ultraviolet lamp in a casing, and an object to be irradiated with ultraviolet rays from the ultraviolet lamp, for example, a flow path through which sample water flows is provided in the casing.

  Taking the total organic carbon measuring device as an example of an analyzer equipped with an ultraviolet irradiation device, the total organic carbon measuring device decomposes the organic carbon in the sample water into carbon dioxide by ultraviolet irradiation, and then the carbon dioxide concentration in the sample water The total organic carbon concentration is measured by detecting. Specifically, a sample oxidation unit that oxidizes carbon in the sample solution to convert it into carbon dioxide and a carbon dioxide detection unit that detects carbon dioxide in the sample solution that has passed through the sample oxidation unit are provided. An ultraviolet irradiation device is used as the part (see Patent Document 1).

  Some sample waters have high organic carbon concentrations and others have low concentrations. If the UV lamp is not lit due to life or failure, the organic carbon in the sample water is not converted to carbon dioxide, so even if the sample water has a high organic carbon concentration, it is detected as the carbon dioxide concentration. Airframe carbon concentration is low. Therefore, even if the detected value of the carbon dioxide concentration is low, it cannot always be determined that the organic carbon concentration in the sample water itself is low, and the ultraviolet ray lamp was not lit. It is possible that the organic carbon was not converted to carbon dioxide.

  Therefore, in the conventional total organic carbon measuring device, in order to confirm that the ultraviolet lamp is lit, it is necessary to take out the ultraviolet lamp from the housing of the ultraviolet irradiation device and start the lamp before starting the analysis. I have confirmed. In addition, there is an all-organic carbon measuring device in which a lighting confirmation window is provided in the ultraviolet irradiation device so that lighting can be confirmed without removing the lamp.

JP 2007-40729 A

  In order to confirm that the ultraviolet lamp is lit, the method of taking the lamp out of the apparatus and confirming it requires eye protection by eye protection when the lamp is viewed directly with the naked eye. Even if protective glasses are used, it is dangerous to turn on the ultraviolet lamp outside the housing.

  In the ultraviolet irradiation device provided with the lighting confirmation window, the lighting is confirmed through a transparent resin plate that does not transmit ultraviolet rays. When the ultraviolet lamp is turned on, oxygen in the air is oxidized and ozone is generated. Therefore, the casing of the ultraviolet irradiation device has a sealed structure so that ozone does not leak to the outside. For this reason, when a lighting confirmation window is provided, a sealing structure around the window is required, resulting in an increase in apparatus cost.

  Therefore, the present invention eliminates the need to take out the lamp from the housing or to provide a confirmation window in the housing in order to confirm the operation of the ultraviolet lamp, and UV irradiation is provided with means that can confirm the operation of the lamp more easily. It is an object of the present invention to provide a total organic carbon measuring apparatus which is an example of an apparatus and an analyzer equipped with the apparatus.

  The ultraviolet irradiation device of the present invention is a device in which an ultraviolet lamp is held in a light-shielding casing. The ultraviolet lamp is provided with a tube made of an ultraviolet light transmissive material. An ultraviolet radiation gas is sealed in the tube body, and lead terminals are drawn out from the sealing portions at both ends of the tube body. The tubular body is held by the holding portion. The holding part has a cylindrical shape, and both end sealing parts of the tubular body are fitted into one opening part of the holding part, and the other opening part of the holding part is made of a visible light transmissive resin that blocks ultraviolet rays. Thus, the lead terminal is sealed so as to protrude.

  The housing accommodates the tube portion of the ultraviolet lamp and the target to be irradiated with ultraviolet light, and holds the ultraviolet lamp in a state where the other opening of the holding part of the ultraviolet lamp is exposed to the outside.

  There are mercury lamps and xenon lamps as ultraviolet lamps, and all of them generate not only ultraviolet rays but also light in the visible light region. In the ultraviolet lamp of the present invention, the member that seals the opening protruding outside the housing among the opening of the holding part is a resin that is transparent to visible light, so the opening of the holding part of the ultraviolet lamp It can be confirmed from the outside of the housing that the ultraviolet lamp is lit through the sealing member.

  The resin generally does not transmit ultraviolet rays. As a normally used sealing member, a pigment that absorbs visible light is often added to the resin so as not to transmit visible light. An example of the sealing member of the present invention is obtained by curing a resin adhesive to which such a pigment is not added.

  The total organic carbon measurement device of the present invention includes a sample oxidation unit that oxidizes carbon in a sample solution to convert it into carbon dioxide, and a carbon dioxide detection unit that detects carbon dioxide in the sample solution that has passed through the sample oxidation unit. The ultraviolet irradiation device of the present invention is used as the sample oxidation part. And the object accommodated in the housing | casing of an ultraviolet irradiation device is the flow path which consists of ultraviolet permeable materials, and a sample solution flows through the flow path.

  In the ultraviolet irradiation device of the present invention, the portion of the opening of the holding portion of the ultraviolet lamp to which the tube portion is attached is inside the housing, but the opposite portion of the opening is exposed to the outside of the housing. Therefore, when the lamp is lit, light in the visible light region leaks outside through the resin sealing the holding portion. Since ultraviolet rays are absorbed by the resin and do not leak outside, safety is maintained. Since the structure that can confirm that the lamp itself is lit is provided, it is not necessary to take the lamp out of the housing in order to confirm the lighting of the lamp, so that the work can be performed safely. In addition, since there is no need to provide a confirmation window in the housing, there is no need for parts for the ozone seal to prevent ozone from leaking from the window material and the joint between the window material and the housing, making the UV irradiation device cheaper. Can be manufactured. Moreover, if such an ultraviolet irradiation device is provided, it contributes to the cost reduction of analyzers, such as a total organic carbon measuring device.

It is sectional drawing which shows the ultraviolet irradiation device of one Example. It is a figure which shows the ultraviolet lamp in the Example, (A) is a partially notched top view, (B) is a front view. It is a flow path figure showing the total organic carbon measuring device to which the ultraviolet irradiation device of one example is applied.

  FIG. 1 is a front sectional view of an ultraviolet irradiation apparatus according to one embodiment, and FIG. 2 shows an ultraviolet lamp according to the embodiment. FIG. 2A is a plan view with a part cut away, and FIG. 2B is a front view.

  The ultraviolet irradiation device 2 has a housing 4 with a built-in ultraviolet lamp 6. An object 8 to be irradiated with ultraviolet rays is also built in the housing 4.

  The housing 4 is a metal block having a sealed structure so that ultraviolet rays do not leak outside and ozone does not leak. The material of the housing is not particularly limited, but is aluminum, for example.

  As shown in FIG. 2, the ultraviolet lamp 6 has a quartz glass cover 12, which is an ultraviolet transmissive material, attached to one opening of a cylindrical holding part 10, and the cover 12 is bent into a U shape. The tube body 14 of the ultraviolet lamp is accommodated, and both ends of the tube body 14 are attached so as to be in the holding unit 10.

  The tube body 14 is made of quartz glass that transmits ultraviolet rays, is an airtight container, and contains mercury and a rare gas or a rare gas halide as a discharge medium. Xenon, argon, or helium can be used as the rare gas, and xenon chloride (XeCl), krypton chloride (KrCl), or the like can be used as the rare gas halide. As a specific example, 100 mg of mercury is sealed in the tube body 14, and argon is sealed as a rare gas so as to have a pressure of 0.5 torr. Lead terminals made of refractory metal such as nickel, tungsten, molybdenum, stainless steel, or titanium are attached to both ends of the tube body 14, and both ends serve as sealing portions. Both-end sealing portions are sealed by melting the quartz glass of the tubular body. Cables 16 are connected to lead terminals protruding from both ends of the tube body 14.

  Both ends of the tube body 14 and the cover 12 are inserted into one opening of the holding unit 10, and the sealing member 18 is filled into the holding unit 10 from the other opening of the holding unit 10, so that the opening of the holding unit 10 is opened. It is sealed. The sealing member 18 is a resin adhesive to which a pigment that absorbs visible light is not added, and is filled and cured from the opening on the lead terminal side of the holding unit 10. The cable 16 connected to the lead terminal is taken out from the holding unit 10 to the outside.

  Returning to FIG. 1, a flow path 8 through which sample water flows as an object to be irradiated with ultraviolet rays is provided in the housing 4 so as to face the ultraviolet lamp 6. The flow path 8 is made of quartz glass, and one connection port 20 protruding to the outside of the housing 4 serves as the sample water inlet, and the connection port 22 protruding to the outside from the housing 4 on the opposite side serves as the sample water outlet. It has become.

  When the ultraviolet lamp 6 is turned on, organic carbon in the sample water 10 flowing through the flow path 8 is decomposed by ultraviolet rays from the lamp 6 to become carbon dioxide. At this time, when the lamp 6 is lit, a part of visible light leaks from the opening of the holding unit 10 through the resin sealing member 18 to the outside of the casing 4, so that the lamp 6 is lit. 4 can be confirmed from the outside. The ultraviolet rays from the lamp 6 are shielded from light by the resin and do not leak outside the housing 4.

  The housing 4 seals the portion holding the lamp holding portion 10 and the portion where the flow path 8 protrudes outside the housing 4 in an airtight state, and the inside of the housing 4 is sealed. Yes. Therefore, even if ozone is generated in the housing, it does not leak out of the housing 4.

  FIG. 3 shows an embodiment in which the present invention is applied to a total organic carbon measuring apparatus for measuring total organic carbon in an aqueous solution as an analyzer using the ultraviolet irradiation apparatus of the present invention.

  There is total organic carbon (TOC) as a method of expressing the degree of contamination of an aqueous solution by the amount of carbon contained in the organic matter in the aqueous solution. A total organic carbon measuring device is used to measure TOC. As a general measurement method for measuring TOC, total carbon (TC) and inorganic carbon (IC) in a sample aqueous solution are measured. There is a method of obtaining a value obtained by subtracting the IC measurement value from the TC measurement value (TOC = TC-IC).

  A schematic configuration diagram of the total organic carbon measuring apparatus is shown in FIG. A sample solution containing organic carbon is introduced from the sample inlet 31, and a certain amount of the phosphoric acid solution accommodated in the phosphoric acid reservoir 33 is added to the sample solution by the phosphoric acid syringe pump 34, and further to the peroxodisulfate reservoir 36. A constant amount of the stored peroxodisulfate solution is added to the sample solution by a peroxodisulfate syringe pump 37. By adding a phosphoric acid solution to the sample solution, inorganic carbon (IC) contained in the sample is converted to carbon dioxide. By measuring the amount of carbon dioxide with the conductivity sensor 41, the concentration of inorganic carbon is measured. On the other hand, a peroxodisulfate solution is added to the sample, and the sample oxidation channel 38 is irradiated with ultraviolet rays by an ultraviolet lamp 39, whereby all the carbon contained in the sample is oxidized and carbon dioxide is generated. The total carbon concentration is measured by measuring the amount of carbon dioxide with the conductivity sensor 42. The total organic carbon concentration is obtained by subtracting the inorganic carbon concentration from the measured total carbon concentration.

  Here, as the sample oxidation channel 38 and the ultraviolet lamp 39, the ultraviolet irradiation device 2 of the embodiment shown in FIG. 1 is used.

  Also, a total organic carbon measuring device that measures with one channel and one conductivity sensor without separating the sample solution reacted with the phosphate solution and peroxodisulfate solution into two channels. You can also. In that case, by turning on / off the ultraviolet lamp that irradiates the sample solution with ultraviolet rays, the inorganic carbon is measured when it is off, and the total carbon is measured when it is on. In other words, inorganic carbon can be measured by measuring the conductivity of the sample solution without irradiating ultraviolet rays, and total carbon can be measured by measuring the conductivity of the sample solution while irradiating ultraviolet rays. . By subtracting the amount of carbon measured when not irradiating ultraviolet rays from the amount of carbon measured when irradiating with ultraviolet rays, the total organic carbon amount can be measured.

  As a total organic carbon measuring device that measures with one flow path and one conductivity sensor, it does not perform ultraviolet irradiation or non-irradiation by turning on / off the ultraviolet lamp, but between the sample solution and the ultraviolet lamp. It is also possible to control the irradiation and non-irradiation of ultraviolet rays by driving the shielding plate with a motor or solenoid.

DESCRIPTION OF SYMBOLS 2 Ultraviolet irradiation apparatus 4 Case 6,39 Ultraviolet lamp 8 Object irradiated with ultraviolet rays 10 Holding part 14 Ultraviolet lamp tube 16 Cable connected to lead terminal 18 Sealing member 38 Sample oxidation flow path 41, 42 Conductivity sensor

Claims (3)

Lead terminals are drawn to the outside from both end sealing portions of the ultraviolet transmissive tube encapsulating the ultraviolet radiation gas, and both end sealing portions are fitted into one opening of the cylindrical holding portion, An ultraviolet lamp sealed so as to project the lead terminal by a sealing member made of a visible light transmitting resin whose other opening shields ultraviolet light; and
The light shielding unit that holds the ultraviolet lamp tube in a state in which the tube portion of the ultraviolet lamp and the target to which the ultraviolet ray is irradiated are housed and the other opening of the holding part of the ultraviolet lamp is exposed to the outside. Ultraviolet irradiation device provided with a sexual housing.   The ultraviolet irradiation device according to claim 1, wherein the resin is obtained by curing a resin adhesive to which a pigment that absorbs visible light is not added. In an all-organic carbon measuring device including a sample oxidation unit that oxidizes carbon in a sample solution to convert it into carbon dioxide, and a carbon dioxide detection unit that detects carbon dioxide in the sample solution that has passed through the sample oxidation unit,
The ultraviolet irradiation device according to claim 1 or 2 is used as the sample oxidation unit,
An all-organic carbon measuring device in which the object housed in a housing of the ultraviolet irradiation device is made of an ultraviolet transmitting material and is a flow path through which a sample solution flows.

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