JPS6140057B2 - - 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, methods for heating the filter section include electric heating or steam heating. However, in the case of electric heating, the lifespan of the heater is short, the cost of outdoor construction is high, the cost of wiring increases, and a special energy source is required for operation. On the other hand, in the case of the steam heating type, it was difficult to obtain steam easily, and extra piping work was required. Furthermore, the connection between the sample gas sampling tube inserted into the flue and the flange of the filter section is subject to the cooling effect of outside air, so the sampling gas may be cooled below the dew point temperature and condensed water may be produced. When hydrogen chloride gas is contained, such as in waste incinerator exhaust gas, this dissolves in condensed water and becomes highly corrosive drain, which can lead to accidents such as corrosion of collection pipes and blockage of pipes. The problem was that it occurred frequently.

SUMMARY OF THE INVENTION An object of the present invention is to provide an inexpensive 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, in the exhaust gas extractor mentioned at the beginning, the heat receiving part at one end is located in the flue, the filter part is heated and kept warm at the center part above the dew point temperature of the exhaust gas, and the heat radiation part at the other end is located in the flue. Exhaust gas is collected by using a heat pipe whose part is exposed to the outside of the flue so that the heat receiving part is located below the axis of the exhaust gas collector and the heat dissipating part is located above the axis of the exhaust gas collector. This is achieved by arranging it at an angle to the axis of the vessel.

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, ie, the clean sampling gas Q, which has passed through the filter 10 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 sampling device inserted into the horizontal opening of the flue wall 5, a flange 11 provided on the exhaust gas sampling device is coupled to a flange 4 that projects outside of the flue wall 5. There is. The flanges 4, 11 support the soaking tube 8 and an external protection tube 14 for reducing heat dissipation therefrom. The opening at the rear end 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 exhaust gas from condensing in the internal filter chamber 9, a heat pipe is installed in the center of the tube in close contact with the outer peripheral surface of the soaking tube 8. 6 and 6' are provided. The heat pipes 6, 6' are in contact with the heat soaking tube 8 as far down as possible on the heat receiving section 2, 2' side at one end, and as far as possible above the heat soaking tube 8 on the heat dissipating section 3, 3' side at the other end. It is arranged so that it is tangential to the position and is therefore inclined in the middle with respect to the axis of the exhaust gas extractor. In that case, the angle of inclination is preferably approximately 5° or more. The reason for this is to allow the condensate to return from the heat radiation section to the heat reception section by its own weight so that the heat pipes 6, 6' can be constructed without a wick, as will be described later. The heat receiving parts 2, 2' at one end of the heat pipes 6, 6' protrude almost horizontally into the flue, and the heat radiating parts 3, 3' at the other end extend almost horizontally to the outside of the flue wall 5 and are exposed. There is.

In this way, the heat receiving parts 2, 2' of the heat pipes 6, 6' are heated by the flue gas, usually at a temperature of 200 to 400°C,
The heat heats and insulates the filter section consisting of the filter chamber 9 and filter 10 through the soaking tube 8 in the center, and further discards excess heat in the heat radiating sections 3 and 3' to raise the filter section above the dew point temperature of the exhaust gas. ,for example
Maintain at around 110-120℃. In the above process, the working fluid in the heat pipes 6, 6' is heated in the heat receiving parts 2, 2' and turns into steam, which turns into a steam flow inside and reaches the heat radiating parts 3, 3', where it is condensed. It becomes a liquid and returns to the heat receiving parts 2, 2' using the slope due to its own weight even without a wick.

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 above, 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 or piping as with electric heating or steam heating methods, resulting in energy savings 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 can be converted to drain during the process, and therefore, there is no possibility of interaction between the drain and dust or hydrogen chloride gas during the sampling pipe. Accidents of pipe blockage, corrosion, or breakage due to the action can also be effectively prevented. Furthermore, even if the exhaust gas sampling device of the present invention is inserted horizontally into the flue, the condensate of the heat pipe returns from the heat radiating section to the heat receiving section under its own weight, so that it can be an inexpensive heat pipe that does not require a heat pipe. Therefore, since this exhaust gas collector only needs to be installed horizontally on the flue wall, machining work on the flue wall side is also facilitated.

[Brief explanation of the drawing]

Fig. 1 is a schematic layout diagram showing a state in which the exhaust gas sampling device of the present invention is attached to a flue wall, and Fig. 2 is a longitudinal section showing an embodiment of the exhaust gas sampling device of the present invention along the - line in Fig. 3. Figure 3 is a schematic diagram of the exhaust gas collector shown in Figure 2 viewed from the direction of arrow _P1 , Figure 4 is a cross-sectional view taken along the - line in Figure 2, and Figure 5 is a schematic diagram of the exhaust gas collector shown in Figure 2. FIG. ₂ is a schematic diagram of the collector viewed from two directions of arrow P. 1... Exhaust gas sampling pipe, 2, 2'... Heat pipe heat receiving section, 3, 3'... Heat pipe heat dissipating section,
6, 6'...heat pipe, 9...filter chamber,
14...External protection tube.

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. The filter section is heated and kept warm at the center to a temperature higher than the dew point temperature of the exhaust gas, and the heat radiating section at the other end is exposed to the outside of the flue. An exhaust gas sampler, characterized in that the heat radiating part is located below the exhaust gas sampler, and the heat radiating part is arranged at an angle with respect to the axis of the exhaust gas sampler. 2. The exhaust gas collector according to claim 1, wherein the heat receiving part and the heat radiating part of the heat pipe are substantially parallel to the axis of the exhaust gas collector, and only the central part of the heat pipe is inclined. Exhaust gas sampler.