JPS6140056B2 - - 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
A flue gas analyzer is installed, and a pretreatment device is installed to remove dust from the sampling gas collected by such an analyzer to maintain the cleanliness required by the flue gas analyzer. Dust removal processing is performed. In general, 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 at the filter section, condensed water is produced. If dust gets mixed into this condensed water, it can clog the filter and cause an increase in pressure loss, and furthermore, the interaction between the condensed water and sulfuric acid mist can lead to rapid corrosion. The filter section is heated to maintain it above the dew point temperature of the exhaust gas to prevent condensed water from forming. Conventionally, methods for heating the filter section using electricity or steam have been adopted as a heating method, but in the case of electric heating, the life of the heater is short, and the cost for outdoor construction is high. Disadvantages include high wiring work costs and the need for a special energy source for operation.On the other hand, steam heating systems have the disadvantages that it is difficult to obtain steam easily, and piping work costs are high. The disadvantage was that it required a special Furthermore, the connection between the exhaust gas sampling pipe 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 and condensed. Water may be generated, 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, corroding the collection pipe and causing the pipe line to become damaged. There was a disadvantage that accidents frequently occurred in which the pipes became blocked or broke.

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, this purpose is such that the heat receiving part at one end is located inside 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 the heat pipe so that it can be inserted into and removed from the exhaust gas sampling pipe and the filter section, and by providing an adjustment mechanism between the heat pipe and the filter section to adjust the insertion/removal position of the heat pipe.

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

In FIGS. 1 to 4, the exhaust gas P in the flue is guided into the soaking cylinder 25 through the exhaust gas sampling pipe 1. The interior of the soaking cylinder 25 is configured as a filter chamber 11, in which a filter 12 is disposed. Filter 1
The exhaust gas, ie, the clean sampling gas Q, which has passed through 2 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 collector inserted into the opening of the furnace wall 5, a flange 26 on the exhaust gas collector side is coupled to the flange 4 protruding from the outer surface of the furnace wall. The flanges 4 and 26 support the soaking tube 25 and an external protection tube 24 (integrated with the flange 4) that reduces heat radiation from the tube. The opening at the rear end of the soaking cylinder 25 is a gasket 8.
It is closed by a lid 9 through the.

In order to maintain the temperature of the soaking tube 25 above the dew point temperature (approximately 110 to 120 degrees Celsius) and to prevent the exhaust gas from condensing in the internal filter chamber 11, the center portion of the soaking tube 25 is
Two heat pipes 3 are inserted into the protection tube 2 and extend in the axial direction in close contact with the outer periphery of the heat pipe 5 . The heat receiving part 13 at one end of the heat pipe 3 is located in the flue, and the heat radiating part 10 at the other end is exposed to the outside of the furnace wall 5.

The heat pipe 3 is installed in the protective tube 2 so that it can be inserted and removed freely, and adjusts the amount of heat received from the exhaust gas P or R at the heat receiving part 13 by adjusting the length of insertion into the furnace wall 5. The filter chamber 9 and the filter 10 are heated through the soaking tube 25 in the center by the heat of the pipe gas.
A heat dissipation section 10
The excess heat is discarded and the filter section is maintained at a temperature above the dew point temperature of the exhaust gas, for example around 110 to 120 degrees Celsius.

The amount of heat received by the heat receiving section 13 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,
One way is to adjust the amount of heat received by changing the diameter of the heat receiving portion 13 of the heat pipe 3, but this method is not versatile. Therefore, in this embodiment, the heat pipe 3 is made removable within the protective tube 2, and the effective length of the heat receiving section 13 is adjusted. Therefore, an adjustment fitting 30 having a screw hole is fixed to the rear end of the protection tube 2, and a support fitting 31 having a through hole corresponding to the position of the screw hole is fixed to the heat pipe 3. By screwing the adjustment screw 15 into the screw hole of the adjustment fitting 30 through the through hole of the support fitting 31 and adjusting the screwed-in length, the effective length of the heat receiving part 13 of the heat pipe 3 can be adjusted. Even if the temperature of the road gas changes, the amount of heat received by the heat receiving section 13 of the heat pipe 3 is adjusted to keep the filter section at about 110 to 120 DEG C. as described above, thereby effectively preventing the generation of condensed water.

The temperature of the filter section can be determined, for example, by placing several temperature-sensitive labels 1 on the rear end of the soaking cylinder 25, which can display the temperature in several levels above and below the above-mentioned 110 to 120 degrees Celsius.
You can easily know by pasting 4.

FIG. 5 shows that the center part of the heat pipe 3 closely penetrates into the heat equalizing body 16 which is in close contact with the outer periphery of the heat equalizing tube 25 forming the filter chamber 11, and the heat receiving part 13 is connected to the furnace. This embodiment shows an embodiment in which the heat dissipation section 10 is directly exposed to the flue gas inside the wall and exposed to the outside air outside the furnace wall, similar to the embodiments shown in FIGS. 1 to 4. In this configuration, the O-ring 40 ensures a seal between the heat pipe 3 and the heat equalizer 16 on the heat radiation section 10 side. The structure of other parts is the same as that of FIGS. 1-4. In the case of this embodiment as well, the only difference is whether or not the heat receiving part 13 of the heat pipe 3 is directly exposed to the flue gas.
It can be said that it has substantially the same function as the one in Figures 4 to 4.

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, clogging and corrosion of the filter caused by condensation of the sampling gas can be prevented. Moreover, since it is a self-heating method of exhaust gas, there is no need for wiring or piping as is required for electric heating or steam heating, 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, FIG. 4 is a side view of the main parts of the exhaust gas sampling device of the present invention, and FIG. 5 is a cross-sectional view of another embodiment of the exhaust gas sampling device of the present invention. FIG. 1...Exhaust gas collection pipe, 3...Heat pipe, 2
5... Soaking cylinder, 10... Heat pipe heat dissipation section, 1
1...Filter chamber, 12...Filter, 13...
Heat pipe heat receiving part, 15...adjustment screw, 16...
...Soaking body.

Claims (1)

[Scope of Claims] 1. In 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, one end of the heat receiving section is connected to the A heat pipe that is located in the flue, has a central portion that keeps the filter section warm above the dew point temperature of the exhaust gas, and has a heat radiating section at the other end exposed to the outside of the flue, is connected to the exhaust gas sampling pipe and the filter section. An exhaust gas sampling device characterized in that an adjustment mechanism is provided between the heat pipe and the filter portion to adjust the insertion/removal position of the heat pipe. 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, wherein the filter section is provided with a temperature sensing element for displaying temperature. 4. The exhaust gas collector according to any one of claims 1 to 3, wherein the heat receiving part of the heat pipe is housed in a protection tube in the flue. . 5. The exhaust gas collector according to any one of claims 1 to 3, wherein the heat receiving part of the heat pipe is exposed in the flue.