JP2011137646A - Electronic cooler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase a response speed of analysis by making it hard to allow the gas, which is produced by the reevaporation of a flocculation liquid such as dewing water or the like, to flow in an inner pipe and shortening the replacement time of sample gas in an outer pipe. <P>SOLUTION: An electronic cooler includes the outer pipe 3 arranged in up and down directions in contact with a heat exchanger 2 and having a gas lead-in part 5 and a drain discharge part 6 provided to the upper and lower parts, respectively, the inner pipe 4 which is inserted in the outer pipe 3 and has a gas lead-out part 7 provided to the upper part and which keeps the lower opening 4H positioned in the outer pipe 3 and the shield structure 12 provided under the lower opening 4H so as to cover at least part of the lower opening in the outer pipe 3 to interrupt the inflow of the gas from the drain discharge part 6 in the lower opening 4H. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electronic cooler that aggregates and removes water vapor or the like contained in a sample gas such as exhaust gas.

Conventionally, in air pollution analyzers such as exhaust gas analyzers, non-dispersive infrared analyzers (NDIR) and chemiluminescence analyzers (CLDs) with nitrogen oxides (NO _x ), sulfur dioxide (SO ₂ ), etc. as measurement targets ) Etc. are used. Since these analytical instruments cause measurement errors due to the interference of moisture in the sample gas, an electronic cooler is connected in front of the analytical instrument.

  This electronic cooler separates and removes moisture from the sample gas by cooling the sample gas and condensing water vapor in the sample gas. As its basic configuration, as shown in Patent Document 1 and Patent Document 2, for example, an outer tube that is closely and vertically disposed on a heat exchanging portion made of a metal having excellent thermal conductivity such as aluminum or copper, And an inner tube provided by being inserted into the outer tube. A gas introduction part for introducing a sample gas is provided in the upper part of the outer pipe, and a drain discharge for discharging drain water generated by condensation of moisture in the sample gas is provided in the lower part of the outer pipe. Is provided. A gas outlet for guiding the sample gas from which moisture has been removed to an analytical instrument is provided at the upper part of the inner pipe, and a lower opening of the inner pipe is disposed inside the outer pipe.

  In such a configuration, the sample gas is introduced into the outer tube from the gas introduction part and descends in the outer tube. At the time of this descent, the sample gas is cooled by receiving a predetermined heat exchange by the heat exchanging unit and separated by moisture condensation, and the dehumidified and dried sample gas flows into the lower opening of the inner tube. Then, the inside of the inner pipe is raised and supplied to the analytical instrument through the gas outlet. On the other hand, the separated water (condensation water) is discharged as drain through a drain discharge portion.

  However, in the conventional electronic cooler, the condensed water once formed by condensation evaporates at the drain discharge part approaching the outside air temperature, or evaporates until reaching the drain discharge part, and becomes a sample gas again. There is a problem of being included and flowing into the inner pipe. As a result, the moisture concentration in the gas becomes high, and there arises a problem that, for example, the measurement error due to the interference effect of moisture by the analytical instrument cannot be sufficiently reduced.

  In addition, due to the problem of cooling efficiency, the lower opening of the inner pipe is positioned in the vicinity of the heat exchanging portion, and on the other hand, it is necessary to take some distance between the heat exchanging portion and the drain discharge portion approaching the outside air temperature. For this reason, the distance from the lower opening of the inner tube to the drain discharge portion becomes longer, and the space inside the outer tube becomes larger. If it does so, the replacement time of the sample gas inside an outer tube will become long, supply of the sample gas to an analytical instrument will be delayed, and there exists a problem that a response speed will become slow.

JP 2005-233890 A Japanese Utility Model Publication No. 63-199049

  Therefore, the present invention has been made to solve the above problems all at once, making it difficult for gas generated by re-evaporation of the condensed liquid such as condensed water to flow into the inner pipe, and for the sample gas inside the outer pipe. The main goal is to shorten the replacement time and increase the response speed of analysis.

  That is, the electronic cooler according to the present invention is arranged in the vertical direction in contact with the heat exchanging portion, and the drain for discharging the drain water condensed at the lower portion and the gas introducing portion for introducing the sample gas into the upper portion. An outer tube provided with a portion, a gas lead-out portion inserted into the outer tube, for leading a sample gas, and an inner tube having a lower opening inside the outer tube, and the outer tube In the inside of a pipe | tube, it is provided so that at least one part may be covered under the said lower opening, and the shielding structure which blocks | prevents that the gas from the said drain discharge part side flows in into the said lower opening is provided.

  In such a case, the shielding structure covers at least a part of the lower opening of the inner tube, so that the gas from the drain discharge part side does not easily flow into the lower opening. Measurement interference components such as moisture contained in the sample gas can be reduced as much as possible. In addition, by providing a shielding structure inside the outer tube, the space inside the outer tube can be reduced, the sample gas replacement time inside the outer tube can be shortened, and the response speed of analysis can be increased. it can.

  In order to make it difficult for the gas from the drain discharge part to flow into the lower opening and to make it difficult for the sample gas introduced into the outer tube to flow from the shield structure to the drain discharge part, the shielding structure includes It is desirable to be formed from a shielding block that is provided below the lower opening and covers substantially all of the lower opening and that forms a flow path for allowing condensed drain water to flow to the drain discharge portion between the inner surface of the outer tube.

  If the condensate stays on the shielding structure, the measurement target component in the sample gas is dissolved in the aggregate liquid, which may cause a measurement error. In order to solve this problem, the shielding structure has an inclined surface on the lower opening side, and the lower end of the inclined surface is connected to a flow path for flowing condensed drain water to the drain discharge portion. desirable.

  According to the present invention configured as described above, the gas generated by the re-evaporation of the condensed liquid such as condensed water is less likely to flow into the inner tube, and the sample gas replacement time in the outer tube is shortened to reduce the analysis response. Speed can be increased.

It is a figure which shows typically the structure of the electronic cooler which concerns on one Embodiment of this invention. It is an enlarged view which mainly shows the shielding block and support member of the embodiment. It is a perspective view which shows the shielding block and support member of the embodiment. It is a figure which shows the modification of a shielding structure. It is a figure which shows the modification of a shielding structure.

  Hereinafter, an embodiment of an electronic cooler 100 according to the present invention will be described with reference to the drawings.

The electronic cooler 100 according to the present embodiment includes, for example, a non-dispersive infrared analyzer (NDIR) or chemical that measures nitrogen oxide (NO _x ) and sulfur dioxide (SO ₂ ) contained in a sample gas such as automobile exhaust gas. It is provided on a line for supplying the sample gas to a gas analyzer such as a luminescence analyzer (CLD), and the sample gas is cooled to condense water vapor as a measurement interference component in the sample gas. To separate and remove moisture from the sample gas.

  Specifically, as shown in FIG. 1, this is provided in close contact with a thermomodule 1 made of, for example, a Peltier element, and a heat absorbing surface of the thermomodule 1, for example, a metal having excellent thermal conductivity such as aluminum or copper A heat exchanging portion 2 comprising: an outer tube 3 that is in close contact with the heat exchanging portion 2 and arranged in the vertical direction; and inserted into the outer tube 3 to form a double tube structure with the outer tube, 3 and an inner tube 4 in which a lower opening 4H is located. In addition, the electronic cooler 100 is provided in the upper part of the outer tube 3, provided in the outer tube 3, a gas introduction part 5 for introducing a sample gas, and provided in the lower part of the outer tube 3. A drain discharge unit 6 for discharging condensed (condensed) condensed liquid (condensed water) to the outside, and a gas derivation for supplying sample gas to the outside (gas analyzer) provided at the upper part of the inner tube 4 Part 7. The heat radiation fin 8 is provided in close contact with the heat radiation surface of the thermo module 1, and the cooling fan 9 for cooling the fin 8 is provided on the opposite side of the heat radiation fin 8 to the thermo module 1. A drain suction pump (not shown) is connected to the drain discharge portion 6, and gas (including condensed water) is sucked from the drain discharge portion 6 at a small capacity of 6 cc / minute, for example. . On the other hand, a derivation suction pump (not shown) is connected to the gas derivation unit 7, and gas is sucked from the gas derivation unit 7 at a large capacity, for example, 700 cc / min.

  The heat exchange unit 2 is disposed in close contact along the outer peripheral surface of the outer tube 3, and is composed of a block body (not shown) divided into two along the vertical direction. A concave groove having a substantially semicircular cross section is formed on the dividing surface of each block body so that the outer tube 3 is fitted.

  A spiral member 10 is provided between the outer tube 3 and the inner tube 4 so as to increase the surface area of the sample gas flowing between the outer tube 3 and the inner tube 4. . The spiral member 10 of the present embodiment is a spring member made of, for example, stainless steel, is a member separated from the outer tube 3 and the inner tube 4, and is configured to be detachable by a shielding block 12 and a support member 13 described later. ing.

  The gas introduction part 5 and the gas lead-out part 7 are provided in the branch block 11 and are connected to the branch block 11 so that the outer tube 3 and the inner tube 4 have a double tube structure. A sample gas pipe (not shown) is connected to the gas inlet 5 and the gas outlet 7. On the other hand, the drain discharge part 6 is formed of a drain block connected to the lower end of the outer tube 3. A drain discharge pipe (not shown) is connected to the drain discharge portion 6.

  In the electronic cooler 100 configured as described above, the sample gas introduced into the outer tube 3 from the gas introduction unit 5 flows downward through the flow path L1 formed between the outer tube 3 and the inner tube 4. . At this time, it flows downward spirally along the spiral member 10 disposed between the outer tube 3 and the inner tube 4. At the time of the descent, the sample gas is cooled to, for example, 2 ° C. to 5 ° C. by receiving a predetermined heat exchange from the heat exchange unit 2 through the outer tube 3, the inner tube 4 and the spiral member 10. And by this cooling, the moisture contained in the sample gas is condensed and separated from the sample gas. Thus, the sample gas dehumidified and dried flows into the lower opening 4H of the inner tube 4 and rises, and is supplied to a gas analyzer (not shown) through the gas outlet 7. On the other hand, the dew condensation water generated by the dew condensation flows below the outer pipe 3 and is discharged to the outside through the drain discharge part 6.

  Thus, as shown in FIGS. 1 and 2, the electronic cooler 100 of this embodiment includes a shielding structure 12 that makes it difficult for gas from the drain discharge portion 6 to flow into the lower opening 4H. Here, the gas from the drain discharge unit 6 includes water vapor generated by the evaporation of condensed water once condensed, and a sample gas containing the water vapor.

  The shielding structure 12 is provided below the lower opening 4H of the inner tube 4 inside the outer tube 3. The shielding structure 12 is provided so as to cover at least a part of the lower opening 4H when the inner tube 4 is viewed in the direction of the central axis C, that is, when the lower opening 4H is viewed from below.

  As shown in FIG. 2 in particular, the shielding structure 12 of the present embodiment is provided below the lower opening 4H so as to cover substantially all of the lower opening 4H and to open a flow path for allowing condensed water to flow to the drain discharge portion 6. It is comprised from the shielding block which forms the flow path L2 between the inner peripheral surfaces of the pipe | tube 3. As shown in FIG. The shielding block 12 has a substantially cylindrical shape having a diameter smaller than the inner diameter of the outer tube 3 and substantially the same as or larger than the outer diameter of the inner tube 4 (see FIG. 3). The material of the shielding block 12 is not limited as long as the surface has hydrophobicity and corrosion resistance, but in this embodiment, it is formed using a fluororesin. The shielding block 12 is supported by a support member 13 so as to be positioned below the lower opening 4H.

  As shown in FIGS. 2 and 3, the support member 13 includes a support rod 131 having one end connected to the lower surface of the shielding block 12 and a lower opening of the outer tube 3 provided at the other end of the support rod 131. And a fixing plate 132 to be fixed. The fixing plate 132 is provided with a through hole 132H for allowing condensed water flowing in the lower portion of the outer tube 3 to flow into the drain discharge portion 6. The fixing plate 132 is fixed at the same time when the drain block (drain discharge portion 6) is connected to the outer tube 3.

  As shown in FIG. 2, the shielding block 12 supported inside the outer tube 3 by the support member 13 is positioned away from the lower opening 4H so that its central axis substantially coincides with the central axis C of the inner tube 4. Placed in. Further, the shielding block 12 is disposed so as to cover the entire lower opening 4H of the inner tube 4 when viewed from the central axis C direction. At this time, a flow path L <b> 2 is formed between the outer peripheral surface of the shielding block 12 and the inner peripheral surface of the outer tube 3 to guide the condensed water to the drain discharge part 6. The flow path L2 has a size that allows dew condensation water to flow downward and prevents sample gas from flowing downward. If the dew condensation water can be flowed downward, the width of the flow path L2 (the distance between the outer peripheral surface of the shielding block 12 and the inner peripheral surface of the outer tube 3) should be as narrow as possible. The shielding block 12 divides the space inside the outer tube 3 into an upper space Sa including the lower opening 4H of the inner tube 4 and a lower space Sb continuous to the drain discharge part 6 via the flow path L2. . With this configuration, the gas from the drain discharge portion 6 (the gas in the lower space Sb) is less likely to flow into the lower opening 4H of the inner tube 4. In addition, the sample gas introduced into the outer tube 3 is less likely to flow into the lower space Sb, and only the upper space Sa is required to replace the sample gas, thereby shortening the sample gas replacement time. Yes.

  In addition, an inclined surface 12 a is formed on the lower opening 4 </ b> H side of the shielding block 12. The shielding block 12 of the present embodiment has a rotating body shape, and the lower opening 4H side (upper end portion) of the shielding block 12 has a shape (pointed shape) that becomes narrower as it goes to the tip, whereby the inclined surface 12a is formed. Is formed. By this inclined surface 12a, the condensed water adhering to the lower opening 4H side (upper end portion) of the shielding block 12 is easy to flow along the inclined surface 12a, and the condensed water stays at the upper end portion of the shielding block 12. The component to be measured in the sample gas is prevented from being dissolved in the condensed water. Further, the inclined surface 12a through which the dew condensation water flows downward is connected to the flow path L2, and the dew condensation water that has flowed down the inclined surface 12a flows into the flow path L2, so that the contact with the sample gas can be reduced. . At this time, by filling the flow path L2 with dew condensation water, it is possible to further prevent the gas from returning from the drain discharge part 6 side. Furthermore, since a drain suction pump is connected to the drain discharge part 6 and sucks gas at, for example, 6 cc / min, it is possible to prevent the dew condensation water from being clogged at the entrance and inside of the flow path L2. In addition, since the suction amount (for example, 6 cc / min) of the discharge suction pump is extremely smaller than the suction amount (for example, 700 cc / minute) of the derivation suction pump, the evacuation suction for the flow of the sample gas to the gas derivation unit. The suction effect by the pump can be substantially ignored.

  Further, the shielding block 12 disposed inside the outer tube 3 by the support member 13 presses and fixes the helical member 10 disposed between the outer tube 3 and the inner tube 4 from below. That is, the spiral member 10 and the shielding block 12 are fixed in a state where the spiral member 10 and the shielding block 12 are in contact with each other. As a result, the condensed water condensed on the surface of the spiral member 10 flows downward along the spiral member 10, and as a result, comes into contact with the inclined surface 12a of the shielding block 12, thereby further promoting the separation of the condensed water. Can do.

<Effect of this embodiment>
According to the electronic cooler 100 according to the present embodiment configured as described above, the shielding block 12 blocks the entire lower opening 4H of the inner tube 4 so that the gas from the drain discharge part 6 flows into the lower opening 4H. Therefore, the measurement interference component of moisture contained in the sample gas derived from the gas deriving unit 7 can be reduced as much as possible.

  Further, by providing the shielding block 12 inside the outer tube 3, the space inside the outer tube 3 can be reduced, and the outer diameter of the shielding block 12 is made substantially the same as the outer diameter of the inner tube 4, so that the sample gas Since the flowing space is reduced, the time for replacing the sample gas in the outer tube 3 can be shortened, and the response speed of the analysis can be increased.

<Other modified embodiments>
The present invention is not limited to the above embodiment.

  For example, in the above embodiment, the shielding structure is constituted by a member (shielding block 12) separated from the outer tube 3, but as shown in FIG. 4, from the lower opening 4H of the inner tube 4 of the outer tube 3. A constriction member 14 for narrowing the space in the outer tube 3 may be provided below so as to block a part of the lower opening 4H and reduce the space inside the outer tube 3. The narrowing member 14 has a flow path L3 formed coaxially with the central axis C of the inner tube. The inner diameter (cross-sectional area) of the flow path L3 is larger than the inner diameter (cross-sectional area) of the lower opening 4H of the inner tube 4. Is also made smaller. An inclined surface 14 a is formed on the upper surface of the constricting member 14. This constricting member 14 also makes it difficult for the gas generated by re-evaporation of the condensed liquid such as condensed water to flow into the inner tube 4, shortens the time for replacing the sample gas in the outer tube 3, and increases the response speed of the analysis. can do.

  Further, as shown in FIG. 5, a part of the lower portion of the lower opening 4H is provided by providing a partition member 15 in which one or a plurality of through holes 15H are formed in the outer tube 3 below the lower opening 4H of the inner tube 4. May be blocked. In this case as well, the gas generated by re-evaporation of the condensed liquid such as condensed water can be prevented from flowing into the inner tube 4, the sample gas replacement time in the outer tube 3 can be shortened, and the analysis response speed can be increased. it can.

  Further, as the shielding structure, in addition to providing another member on the outer tube 3, the outer tube 3 may be configured such that the inner diameter of the outer tube 3 is reduced below the lower opening 4 </ b> H of the inner tube 4.

  In addition, although the electronic cooler of the embodiment has a single flow path, it may be a cooler having a plurality of flow paths.

  In addition, it goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 100 ... Electronic cooler 2 ... Heat exchange part 3 ... Outer tube 4 ... Inner tube 4H ... Lower opening 5 ... Gas introduction part 6 ... Drain discharge part 7 ... Gas lead-out part 12 ... shielding structure (shielding block)
12a ... inclined surface L2 ... flow path

Claims (3)

An outer pipe provided in a vertical direction in contact with the heat exchanging part, provided with a gas introducing part for introducing a sample gas at the upper part and a drain discharging part for discharging the condensate at the lower part;
An inner tube that is inserted into the outer tube and is provided with a gas deriving portion for deriving sample gas at the upper portion, and a lower opening is located inside the outer tube;
An electronic cooler comprising: a shielding structure provided inside the outer tube so as to cover at least a part of the lower opening and covering a gas from the drain discharge portion side from flowing into the lower opening.   The shielding structure is configured by a shielding block which is provided below the lower opening and covers substantially all of the lower opening, and forms a flow path for allowing the condensate to flow to the drain discharge portion between the inner surface of the outer tube. The electronic cooler according to claim 1.   3. The electronic cooler according to claim 1, wherein the shielding structure has an inclined surface on the lower opening side, and a lower end of the inclined surface is connected to a flow path for flowing the condensate to the drain discharge portion.