JPS6140055B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exhaust gas sampling device in which an exhaust gas sampling tube is inserted into a flue, and the exhaust gas led out through the exhaust gas sampling tube is supplied to a gas analyzer via a filter section.

The flues of thermal power plants and garbage incinerators usually have
An exhaust gas analyzer is installed, and a pre-treatment device is provided to remove dust in the sampling gas flow path collected by such an analyzer to maintain the cleanliness required for the exhaust gas analyzer. Dust removal processing is performed as follows. Generally, exhaust gas contains not only a large amount of dust and sulfuric acid mist, but also water vapor, and when this temperature drops below the dew point temperature in the filter section, condensed water is generated. If dust gets mixed in with this condensed water, it can clog the filter and cause an increase in pressure loss, and furthermore, the condensed water and sulfuric acid mist interact, causing rapid corrosion. The filter section is heated to maintain it above the dew point temperature of the exhaust gas to prevent water from condensing. Conventionally, such heating methods have been adopted to electrically or steam-heat the filter section, but in the case of electric heating, the lifespan of the heater is short, the cost for outdoor construction is high, and wiring The disadvantages are that construction costs are high and a special energy source is required for operation.On the other hand, in the case of steam heating, it is difficult to obtain steam easily, and piping work costs are high. It had the disadvantage of being necessary. Furthermore, the connection between the sample gas sampling tube inserted into the flue and the flange of the filter section is not heated by the exhaust gas, but is instead cooled by the outside air, so the sampling gas is cooled below the dew point temperature. Condensed water may be produced, especially if it contains hydrogen chloride gas such as garbage incinerator exhaust gas, this will dissolve in the condensed water and become highly corrosive drain.
This method has the disadvantage that accidents frequently occur in which the collection tube becomes corroded and the conduit is blocked or broken.

SUMMARY OF THE INVENTION An object of the present invention is to provide an exhaust gas sampling device that can effectively heat and maintain a filter section above the dew point temperature in order to eliminate the above-mentioned drawbacks.

According to the present invention, the heat receiving part at one end is located in the flue, the filter part is kept warm at the center part above the dew point temperature of the exhaust gas, and the heat radiating part at the other end is exposed to the outside of the flue. This is achieved by providing a heat pipe and an adjustment mechanism that can adjust the insertion length of the entire extractor containing the heat pipe into the flue.

Next, the present invention will be explained in more detail with reference to the drawings.

In the illustrated apparatus, the exhaust gas P in the flue is guided into the soaking cylinder 8 through the exhaust gas sampling pipe 1 . The interior of the soaking cylinder 8 is configured as a filter chamber 9, in which a filter 10 is disposed. The exhaust gas that has passed through the filter 10, that is, the clean sampling gas Q, is supplied via a gas conduit 7 to a gas analyzer (not shown). On the other hand, in order to support the entire exhaust gas sampler inserted into the opening of the furnace wall 5, a flange 24 attached to the exhaust gas sampler is coupled to a flange 4 protruding from the outer surface of the furnace wall. The flanges 4, 24 support the soaking tube 8 and an external protection tube 23 which reduces heat radiation therefrom. The rear end opening of the soaking cylinder 8 is closed by a packing 12 and a lid 13.

In order to maintain the temperature of the soaking tube 8 above the dew point temperature (approximately 110 to 120 degrees Celsius) and to prevent the exhaust gas from condensing in the filter chamber 9 inside, the center portion is in close contact with the outer periphery of the soaking tube 8 in the axial direction. Two heat pipes 6 are provided that extend to. The heat receiving part 2 at one end of the heat pipe 6 is located in the flue, and the heat radiating part 3 at the other end is exposed to the outside of the furnace wall 5. Thus, usually 200
The heat receiving part 2 of the heat pipe 6 is heated by the flue gas R at ~400°C, the filter part consisting of the filter chamber 9 and the filter 10 is heated and kept warm through the soaking tube 8 in the center, and the heat radiating part is further heated. Step 3 discards excess heat and heats the filter section to a temperature above the dew point temperature of the exhaust gas, e.g.
Maintain at around 110-120℃.

The amount of heat received from the heat receiving section 2 changes significantly depending on the temperature of the exhaust gas in the flue, and therefore the temperature of the filter section can also change significantly. To eliminate this inconvenience,
The amount of heat received may be adjusted by adjusting the diameter of the heat receiving section 2 of the heat pipe, but it is also possible to adjust the effective length of the heat receiving section 2 by configuring the flange 24 so that it can move on the external protection tube 23. good. Because of the latter method, a gasket 25 is interposed between the flange 24 and the external protection tube 23 to maintain a seal. An adjustment fitting 20 having a screw hole is fixed to the flange 24, and a support fitting 26 having a through hole corresponding to the position of the screw hole is fixed to the rear end of the external protection tube 23. By screwing the adjusting screw 15 into the screw hole of the adjusting fitting 20 through the through hole of the support fitting 26 and adjusting the length of the screw, the insertion length of the entire exhaust gas sampling device into the furnace wall can be adjusted. Therefore, even if the temperature of the flue gas changes, it is possible to adjust the amount of heat received by the heat receiving part 2 of the heat pipe 6 and set the filter part to about 110 to 120 degrees Celsius as described above to efficiently prevent the generation of condensed water. can.

The temperature of the filter section can be determined, for example, by placing several temperature-sensitive labels 14 on the rear end of the soaking tube 8, which can display the temperature in several levels above and below the 110 to 120 degrees Celsius mentioned above.
You can easily find out by pasting the .

As described above, the present invention does not have any of the above-mentioned drawbacks of the electric heating method or the steam heating method, and effectively utilizes the isothermal effect of the heat pipe to heat the filter section using the heat of the exhaust gas to reach the dew point temperature of the exhaust gas. By maintaining the temperature within the above predetermined range, it is possible to prevent clogging and corrosion of the filter caused by condensation of the collected exhaust gas. Furthermore, since it is a self-heating method using exhaust gas, there is no need for wiring and piping as with electric heating or steam heating methods, resulting in energy saving and low cost, and maintenance is simple and easy.
Furthermore, since the gas sampling pipe and the filter chamber are maintained at a temperature higher than the dew point temperature of the exhaust gas, the sampling gas does not turn into drain during the process, and therefore, the condensate and dust or hydrogen chloride gas etc. in the sampling pipe do not mix. Accidents of pipe blockage, corrosion, or breakage due to interaction can also be effectively prevented.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical cross-sectional view showing the exhaust gas sampling device of the present invention attached to the furnace wall, and FIG. 2 is a vertical cross-sectional view showing one embodiment of the exhaust gas sampling device of the present invention, with the adjustment mechanism omitted. , FIG. 3 is a cross-sectional view taken along the - line in FIG. 2, and FIG. 4 is a side view showing one embodiment of the exhaust gas sampling device of the present invention. DESCRIPTION OF SYMBOLS 1...Exhaust gas sampling pipe, 2...Heat pipe heat receiving part, 3...Heat pipe heat radiation part, 4...Flute wall flange, 5...Flute wall, 6...Heat pipe, 8
... Soaking cylinder, 9 ... Filter chamber, 10 ... Filter, 15 ... Adjustment screw, 23 ... External protection tube,
24...Flange.

Claims (1)

[Scope of Claims] 1. In an exhaust gas sampling device in which an exhaust gas sampling pipe is inserted into a flue and the exhaust gas led out through the exhaust gas sampling pipe is supplied to a gas analyzer via a filter part, one end of the heat receiving part is located inside the flue. a heat pipe whose central part keeps the filter section warm above the dew point temperature of the exhaust gas and whose heat dissipation section at the other end is exposed to the outside of the flue; and the smoke of the entire collector containing this heat pipe. An exhaust gas sampling device characterized by being provided with an adjustment mechanism that can adjust the length of insertion into the road. 2. The exhaust gas sampling device according to claim 1, wherein the adjustment mechanism is of an adjustment screw type. 3. The exhaust gas sampling device according to claim 1 or 2, further comprising a temperature sensing element for displaying the temperature of the filter section.