JP6548562B2 - Dehumidifying module and gas analyzer equipped with the dehumidifying module - Google Patents

Description

  The present invention relates to a dehumidifying module mounted on a gas analyzer, and more particularly to a dehumidifying module capable of maintaining the dehumidifying performance normally even at a high temperature of 80 to 120 ° C. and a gas analysis to which the dehumidifying module is applied It relates to the device.

  The combustion gas discharged from an exhaust gas generator such as a boiler for burning coal or heavy oil or a waste incinerator contains components such as nitrogen oxides (NOx) and sulfur oxides (SOx). For this reason, the concentration of the component is constantly measured by a gas analyzer, and the analysis result by this gas analyzer is used to control denitration and desulfurization.

In addition, the installer of these exhaust gas generators is obliged to measure the concentration of nitrogen oxides, sulfur oxides, etc. in the exhaust gas at a predetermined measurement cycle. Therefore, in thermal power plants, waste incinerators, etc. where large-scale exhaust gas generators with exhaust gas volumes above a prescribed standard are installed, continuous flue gas exhaust monitoring devices are installed to constantly monitor the concentration of flue gas. ing.
For example, Patent Document 1 is an example of a gas analyzer that analyzes exhaust gas flowing in a flue in this way.

  The gas analyzer has a sampling line for sampling and sampling a portion of the exhaust gas flowing through the flue. The target component in the exhaust gas sampled by this gas sampling line is quantitatively measured by a gas analyzer.

FIG. 4 shows an outline of the configuration of a conventional sampling line.
A gas sampling unit 1, a gas conditioner 2, and a gas suction unit 3 are connected in series to the sampling line, and the exhaust gas drawn from the flue by the gas suction unit 3 is taken in via the gas collection unit 1 There is.

Japanese Patent Application Publication No. 2002-214216

  By the way, the exhaust gas that has passed through the gas collector 1, the gas conditioner 2, and the gas aspirator 3 is cooled by the cooler 4, and then passes through the dehumidifying module 5, the flow checker 6, and the filter 7 for dehumidifying the water in the sample gas. It is measured quantitatively by the gas analyzer 8.

  Here, the reason that the dehumidifying module 5 is disposed at the front stage of the gas analyzer 8 is that the water vapor is contained in the gas when each component such as nitrogen oxide (NOx) and sulfur oxide (SOx) is measured. If this is done, measurement error will occur and it will lead to failure of the measurement sensor.

  The dehumidifying module 5 composed of hollow fibers of fluororesin material is non-porous and can only transmit water vapor, and does not transmit required nitrogen oxides (NOx) and sulfur oxides (SOx), etc. Therefore, it is an effective means for a gas analyzer. The hollow fibers are tube-shaped, and when gas analysis works, there is a slight gap between adjacent hollow fibers to allow water vapor to pass through.

  However, the hollow fiber of the fluororesin material has a low softening point temperature of 120 ° C. When the temperature is higher than the softening point temperature, although the hollow fiber of the fluorocarbon resin material does not melt the material, its volume can be rapidly expanded and the shape can not be maintained by the gas pressure applied inside the hollow fiber, It is easy to deform.

  If the exhaust gas is passed as it is without lowering the temperature of the exhaust gas at the front stage of the dehumidifying module 5, the hollow fiber is exposed to a high temperature gas of 80 to 120 ° C. As a result, although there is a slight gap between the original hollow fibers, the hollow fibers are attached to each other due to the volume expansion or deformation of the hollow fiber accompanying the high temperature, and the gap only allows water vapor to pass through There is a risk that the dehumidification function can not be performed due to the disappearance.

  For this reason, conventionally, it was necessary to cool the temperature of the exhaust gas to 60 ° C. at the front stage of the dehumidifying module 5.

  The present invention has been made in view of such conventional problems, and a dehumidifying module capable of normally maintaining dehumidifying performance even at a high temperature of 80 to 120 ° C. as a sample gas temperature, and this dehumidifying module are applied To provide a gas analyzer installed in a gas sampling line that measures components such as nitrogen oxides (NO.sub.x) and sulfur oxides (SO.sub.x) contained in flue gases such as various boilers and waste incinerators. To aim.

  For this reason, the present invention (claim 1) is a dehumidifying module for removing water vapor from the exhaust gas to analyze the components contained in the exhaust gas of the flue, and a braided yarn woven into a braided structure is formed around the outer periphery A plurality of tube-shaped hollow fibers which are mounted and through which the exhaust gas flows therethrough are provided, and the braided yarn is made of a material having a softening point temperature higher than that of the material of the hollow fibers.

In the dehumidifying module, the exhaust gas passes through the inside of the hollow fiber. A braided yarn made of a material having a softening point temperature higher than that of the material of the hollow fiber is braided in the outer periphery of the hollow fiber. For this reason, even if the hollow fiber is exposed to high temperature exhaust gas, its shape is maintained. That is, since the hollow fiber does not expand or deform, its dehumidification performance is normally maintained.
Therefore, the same dehumidification performance can be obtained even if the exhaust gas is not cooled.

  The present invention (claim 2) is an invention of a dehumidifying module, wherein the braided yarn is a fiber made of resin or metal, and the softening point temperature of the material is 130 ° C. or higher. Do.

  When the softening point temperature of the material of the braided yarn is 130 ° C. or more, expansion and deformation of the hollow fiber can be reliably prevented. Therefore, its dehumidification performance is reliably maintained normal.

  Furthermore, the present invention (claim 3) is an invention of a dehumidifying module, wherein the resin is a group consisting of polyester, polyamide, acrylic resin, polyimide, polyamide, polypropylene, rayon, acetate, vinylon, polyvinyl chloride, and polyurethane. It is characterized in that it is one or more selected.

  Furthermore, the present invention (claim 4) is an invention of a dehumidifying module, wherein the temperature of the exhaust gas flowing into the hollow fiber is 80 to 120 ° C.

  Even if the exhaust gas is not cooled, the dehumidifying performance can be obtained even if it flows into the dehumidifying module as it is at 80 to 120 ° C.

  Furthermore, the present invention (claim 5) is an invention of a gas analyzer, characterized in that the dehumidifying module according to any one of claims 1 to 4 is mounted on a sampling line of the exhaust gas.

  Furthermore, the present invention (claim 6) is an invention of a gas analyzer, wherein the flue gas of the flue is a boiler or a waste incinerator flue gas.

  Furthermore, the present invention (Claim 7) is an invention of a gas analyzer, wherein the exhaust gas contains at least one component of nitrogen oxide and sulfur oxide.

  As described above, according to the present invention, since the outer periphery of the hollow fiber includes the braided yarn woven into a braided shape made of a material whose softening point temperature is higher than the material of the hollow fiber, the hollow fiber Its shape is maintained even if it is exposed to high temperature exhaust gas. That is, since the hollow fiber does not expand or deform, its dehumidification performance is normally maintained. Therefore, the same dehumidification performance can be obtained even if the exhaust gas is not cooled.

External view of hollow fiber with braided yarn mounted around its periphery Simplified configuration diagram of the dehumidifying module (example) Simplified configuration diagram of the dehumidifying module (comparative example) Diagram showing the outline of the conventional sampling line configuration

Hereinafter, embodiments of the present invention will be described. A block diagram of an embodiment of the present invention is shown in FIG. 1 and FIG.
FIG. 1 shows the appearance of the hollow fiber. The hollow fiber 11 is formed in a tube shape so that the exhaust gas sampled at the center passes through. A braided yarn 13 woven in a braided shape is mounted around the outer periphery of the hollow yarn 11.

Both ends of the braided yarn 13 and the hollow yarn 11 are cut leaving a necessary length. The ends of the braided yarn 13 are heat welded so as not to be loosened. The heat welding is performed by heating while sandwiching the periphery of the end portion of the braided yarn 13 with a heater (not shown).
The hollow fiber 11 is formed of a non-porous membrane. The material of the hollow fiber 11 is preferably a fluorine-based resin, and particularly preferably a fluorine-based ion exchange resin.

  As the fluorine-based ion exchange resin, a copolymer having a repeating unit based on tetrafluoroethylene (hereinafter referred to as TFE) and a repeating unit having an ion exchange group is preferable, and in particular, a repeating unit based on TFE and a sulfone A copolymer having a repeating unit based on perfluorovinyl ether having an acid group is preferred.

  The braided yarn 13 is made of resin or metal fibers. The material of the braided yarn 13 desirably has a softening point temperature higher than that of the hollow fiber 11, and in particular, one having a softening point temperature of 130 ° C. or more is preferable. The softening point temperature of the material of the braided yarn 13 is preferably 140 ° C. or more, more preferably 150 ° C. or more, and particularly preferably 160 ° C. or more. As the material of the braided yarn 13, when the material having a softening point temperature of 130 ° C. or more is a resin, for example, polyester, polyamide, acrylic resin, polyimide, polyamide, polypropylene, rayon, acetate, vinylon, polyvinyl chloride, and polyurethane And at least one selected from the group consisting of

  A simplified block diagram of the dehumidifying module 20 is shown in FIG. In FIG. 2, a hollow yarn 11 to which a braided yarn 13 shown in FIG. 1 is attached is disposed in a cylindrical casing 21. Both ends of the hollow yarn 11 to which the braided yarn 13 is attached are fixed by an epoxy resin 23 or the like having heat resistance. The inner diameter of the casing 21 is, for example, 30 to 50 mm in diameter and 700 to 1300 mm in length. Inside the casing 21, 20 to 100 hollow yarns 11 to which the braided yarn 13 is attached are disposed. Therefore, the gaps between the hollow fibers 11 are visible to the naked eye.

  In order to efficiently permeate the water vapor contained in the gas from the hollow fiber, the dried air is flowed from the purge gas inlet 28 in the direction opposite to the gas flow, and the air containing the water vapor is discharged from the purge gas outlet 29 Do. There are two methods of this purge method: a self purge method in which a part from the gas outlet 29 is returned to the purge gas inlet 28, and an external purge method in which it is separately introduced from the external system into the purge gas inlet 28.

  In such a configuration, a high temperature sample gas of 80 to 120 ° C. flows into the gas inlet 25 of the dehumidifying module 20 without being cooled. If the braided yarn 13 is not attached as in the prior art, when the hollow fiber 11 exceeds 120 ° C., which is the softening point temperature of the hollow fiber 11, the shape which has been maintained until melting does not have its shape. It can not be maintained, it will be in a state of sudden deformation.

  In this case, particularly under conditions where the sampling gas passes through the interior of the hollow fiber 11 and a constant gas pressure is applied, the hollow fiber 11 has a high gas pressure when the softening point temperature of 120 ° C. is exceeded. It swells and deforms rapidly depending on the temperature, and the degree of deformation can be easily confirmed even with the naked eye.

  The sample gas is introduced from the gas inlet 25, dehumidified while passing through the center of the hollow fiber 11, and then discharged from the gas outlet 27. Here, in the present embodiment, since the braided yarn 13 made of a material whose softening point temperature is higher than the material of the hollow fiber 11 is mounted around the hollow fiber 11, the hollow fiber 11 has a high temperature of 80 to 120 ° C. The shape is maintained even if exposed to That is, since the hollow fiber 11 does not expand or deform, a gap for water vapor to be dissipated is maintained unchanged between the hollow fiber 11 and its dehumidifying performance is normally maintained.

  Therefore, it is possible to obtain the same dehumidifying performance even without the cooler 4 which has been conventionally installed. Alternatively, even in a plant in which the cooler 4 has already been installed, the need for operating the cooler 4 is eliminated, which leads to a reduction in operating cost.

Example 1
As an example, the hollow fiber 11 of the dehumidifying module 20 is made of a fluorocarbon resin. The braided yarn 13 was formed of polyester having a softening point temperature of 150 ° C. or more. The inner diameter of the casing 21 is 30 mm in diameter and 700 mm in length. Thirty-five hollow fibers 11 to which the braided yarn 13 was attached were disposed on the inside of the casing 21 at substantially equal intervals. Then, a sample gas having a gas temperature of 120 ° C. and a dew point of 13 ° C. was introduced from the gas inlet 25 of the dehumidifying module 20. Dry air with a dew point of -10 ° C. was introduced from the purge gas inlet 28 by an external purge method. As a result, a sample gas with a dew point of −10 ° C. was obtained from the gas outlet 27.

(Comparative example 1)
On the other hand, as a comparative example, the hollow fibers 31 of 35 fluorocarbon resin materials were arranged in the same manner as in the embodiment in the casing 21 of the dehumidifying module 30 shown in FIG. The present comparative example has the same configuration as that of the embodiment of FIG. 2 except that the braided yarn 13 is not attached to the hollow fiber 31. Then, a sample gas having a gas temperature of 120 ° C. and a dew point of 13 ° C. was introduced from the gas inlet 25 of the dehumidifying module 30. Dry air with a dew point of -10 ° C. was introduced from the purge gas inlet 28 by an external purge method.

At this time, the hollow fiber 31 can not maintain its shape, and expands and deforms so that it can be clearly confirmed even with the naked eye. That is, adjacent hollow fibers 31 are attached to each other and no gap can be seen between the hollow fibers 31 at all. As a result, the dew point of the gas outlet 27 remained at 13 ° C. at the gas inlet 25.
As described above, when the braided yarn 13 is not attached to the hollow yarn 31, the shape of the hollow yarn 31 of the dehumidifying module 30 is deformed, and the dehumidifying performance is not obtained.

11 hollow fiber 13 braided yarn 20, 30 dehumidifying module 21 casing 23 epoxy resin etc. 25 gas inlet 27 gas outlet 28 purge gas inlet 29 purge gas outlet

Claims (7)

A dehumidifying module for removing water vapor from exhaust gas to analyze components contained in flue gas of the flue,
A braided yarn braided in a braided manner is mounted around the outer periphery, and a plurality of tube-shaped hollow fibers through which the exhaust gas flows in and pass through the inside are provided,
The dehumidifying module, wherein the braided yarn is made of a material having a softening point temperature higher than that of the material of the hollow fiber.   The said braided yarn is a fiber which uses resin or a metal as a material, The softening point temperature of this material is 130 degreeC or more, The dehumidification module of Claim 1.   The dehumidifying module according to claim 2, wherein the resin is at least one selected from the group consisting of polyester, polyamide, acrylic resin, polyimide, polyamide, polypropylene, rayon, acetate, vinylon, polyvinyl chloride, and polyurethane.   The temperature of the waste gas which flows into the said hollow fiber is 80-120 degreeC, The dehumidification module as described in any one of Claims 1-3.   A gas analyzer characterized in that the dehumidifying module according to any one of claims 1 to 4 is mounted on a sampling line of the exhaust gas.   The gas analyzer according to claim 5, wherein the flue gas of the flue is a boiler or a waste incinerator flue gas.   7. The gas analyzer according to claim 5, wherein the exhaust gas contains at least one component of nitrogen oxide and sulfur oxide.

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