JP4164973B2 - Sulfuric acid gas concentration meter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sulfuric acid gas meter that continuously measures the concentration of sulfuric acid gas in exhaust gas in a flue of a combustion facility or the like.
[0002]
[Prior art]
Since exhaust gas discharged from combustion facilities such as boilers and garbage incinerators contains harmful components such as sulfur oxides, it is necessary to remove them with a flue gas treatment device or the like. In addition, it is necessary to measure the concentration of sulfur oxides in the exhaust gas discharged from the combustion facility or the flue gas treatment device.
[0003]
Here, sulfuric acid gas is mentioned as the sulfur oxide in the exhaust gas. The concentration measurement of the sulfuric acid gas was performed by neutralizing titration after the collected sulfuric acid gas was once dissolved in water and ionized as an aqueous solution.
[0004]
[Problems to be solved by the invention]
However, the concentration measurement of sulfuric acid gas is performed by titration, which is troublesome and difficult to perform continuously.
[0005]
Then, the objective of this invention is providing the sulfuric acid gas concentration meter which can solve the said subject and can measure the sulfuric acid gas concentration in waste gas continuously.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the sulfuric acid gas concentration meter of the present invention is a sulfuric acid gas concentration meter for measuring the concentration of sulfuric acid gas in the flue gas of a combustion facility, etc. The exhaust pipe for discharging exhaust gas to the pipe and the flue has a cavity having two transparent windows facing each other, and the temperature of the exhaust gas that is provided in the intake pipe and passes through the intake pipe is 400 ° C. or higher and 450 ° C. or lower. A preheating unit for irradiating light, a light source for irradiating light into the cavity, a reflection mirror disposed outside the cavity for reciprocating the light from the light source into the cavity multiple times, and the light after reciprocation And a calculating means for calculating the concentration of sulfuric acid gas in the exhaust gas by spectroscopic analysis.
[0007]
In addition to the above configuration, the sulfuric acid gas concentration meter of the present invention is preferably provided with a filter for removing dust in the exhaust gas in the middle of the suction pipe.
[0008]
In addition to the above configuration, the sulfuric acid gas concentration meter of the present invention is preferably provided with a pump for forcibly discharging the exhaust gas in the cavity into the flue in the middle of the discharge pipe.
[0009]
In addition to the above configuration, the sulfuric acid gas concentration meter of the present invention is preferably provided with a heater for heating the cavity in the cavity.
[0010]
Here, when sulfuric acid gas is heated to a temperature of 400 ° C. or higher and 450 ° C. or lower, it decomposes into SO ₃ and water vapor, so the concentration of sulfuric acid gas in the exhaust gas is measured by determining the concentration of SO ₃ after heating. can do.
[0011]
That is, the SO ₃ concentration can be measured by reciprocating the light from the light source a plurality of times to the exhaust gas preheated in the preheating part immediately before being sucked into the cavity from the flue and performing spectral analysis of the light after the reciprocation. it can. The concentration of sulfuric acid gas in the exhaust gas can be accurately measured from the concentration of SO ₃ . Moreover, since the exhaust gas sucked into the cavity from the flue is discharged into the flue after the concentration measurement, the concentration of sulfuric acid gas in the exhaust gas can be continuously measured. In addition, by providing a filter in the middle of the suction pipe, dust can be removed when the exhaust gas contains dust, so that dust enters the cavity and scatters light from the light source, resulting in measurement errors. I will not let you. Furthermore, by providing a pump that forcibly exhausts the exhaust gas in the cavity in the middle of the exhaust pipe, the exhaust gas is always introduced into the cavity without decreasing the flow rate of the exhaust gas flowing in the flue, and after concentration measurement, Since it is discharged into the flue, the exhaust gas does not stay in the cavity. Since the reflecting mirror is arranged outside the cavity, it is not corroded by the exhaust gas.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0013]
FIG. 1 is a conceptual diagram showing an embodiment of a sulfuric acid gas concentration meter according to the present invention.
[0014]
In the figure, reference numeral 1 denotes a flue such as a combustion facility. One end (suction port) of the suction pipe 3a is attached to the upstream side of the flue 1 where the exhaust gas flows in the direction of the arrow 2, and one end (discharge port) of the discharge pipe 4a is attached to the downstream side of the flue 1. ing. The other end of the suction pipe 3a is connected to the suction port 5a of the filter 5 (for example, a container filled with glass wool), and the discharge port 5b of the filter 5 is connected to the suction port 6a of the cavity 6 via the suction pipe 3b. It is connected to the.
[0015]
Between the intake pipes 3b and 3c, there is provided a preheating unit 23 for setting the temperature of the exhaust gas passing through the intake pipes 3a to 3c to 400 ° C. or higher and 450 ° C. or lower. 24 is connected. The preheating unit 23 has a preheating chamber 23 a that temporarily stores exhaust gas and is covered with a heat insulating material, and the temperature of the exhaust gas in the preheating chamber 23 a is adjusted by a heater 23 b connected to the temperature regulator 24. It has become.
[0016]
The discharge port 6b of the cavity 6 is connected to the suction port of the pump 7 through the discharge pipe 4b. The discharge port of the pump 7 is connected to the other end of the discharge pipe 4a. The cavity 6 is a substantially cylindrical sealed container, and has transparent windows 8a and 8b made of two transparent members (for example, quartz glass) facing each other. A light source (for example, a xenon lamp) 9 and a spectroscope 10 are arranged on one end face side (left side in the figure) of the cavity 6. A plurality of reflection mirrors 11 a to 11 c are arranged on both end surfaces of the cavity 6 so that the light emitted from the light source 9 enters the spectroscope 10 after reciprocating in the cavity 6 a plurality of times. These cavities 6 and reflecting mirrors 11a to 11c constitute a multi-pass cell.
[0017]
The spectroscope 10 is provided with a light detection element (for example, a photodiode) 12 that receives the light that has been dispersed after reciprocating in the cavity 6 and converts it into an electrical signal. The light detection element 12 obtains the SO ₃ concentration in the exhaust gas based on the signal from the light detection element 12, and calculates the sulfuric acid gas concentration from the SO ₃ concentration (performs multivariate analysis) (for example, a personal computer) 25 Is connected. The spectroscope 10, the light detection element 12, and the arithmetic unit 25 constitute a calculation means.
[0018]
A heater 15 is disposed in the cavity 6, and the exhaust gas sucked into the cavity 6 is heated to a temperature of 400 ° C. or higher and 450 ° C. or lower under the control of the temperature regulator 14.
[0019]
Here, sulfuric acid gas decomposes into SO ₃ and water vapor when heated to a temperature of 400 ° C. or higher and 450 ° C. or lower. Therefore, by determining the concentration of SO ₃ after heating, the concentration of sulfuric acid gas in the exhaust gas is reduced. It can be measured. That is, exhaust gas is sucked into the cavity 6 from the flue 1, the light from the light source 9 is reciprocated in the cavity 6 a plurality of times, and is received by the light detection element 12. The SO ₃ concentration can be obtained by spectroscopic analysis according to 25. The concentration of sulfuric acid gas in the exhaust gas can be calculated from this SO ₃ concentration. Since the exhaust gas sucked into the cavity 6 from the flue 1 is discharged into the flue 1 after measuring the concentration, the concentration of sulfuric acid gas in the exhaust gas can be continuously measured.
[0020]
(Reason for setting the temperature of exhaust gas to 400 ° C to 450 ° C)
FIG. 2 is a graph showing the relationship between the composition of SO ₃ , the concentration of water, and the temperature. The horizontal axis represents the water concentration axis, and the vertical axis represents the SO ₃ composition axis.
[0021]
From the figure, it can be seen that at 350 ° C. or lower, the composition of SO ₃ decreases as the concentration of water increases. That is, SO ₃ combines with water vapor at 350 ° C. or lower to form sulfuric acid gas, so the concentration cannot be measured. However, at 350 ° C. or higher, the SO ₃ composition does not change much even if the water concentration increases. I understand. However, the concentration of SO ₃ cannot be measured because it decomposes into SO ₂ at 450 ° C. or higher. For this reason, it is necessary to maintain the temperature of exhaust gas at 400 ° C to 450 ° C.
[0022]
FIG. 3 is a conceptual diagram of an exhaust gas sampling apparatus showing a modification of the filter used in the sulfuric acid gas concentration meter of the present invention. FIG. 4 is a view showing a state in which the exhaust gas sampling device shown in FIG. 3 is attached to the flue of the combustion facility.
[0023]
The filter 5 shown in FIG. 1 has a container filled with glass wool, whereas the exhaust gas sampling device 26 is an exhaust gas sampling device that samples only exhaust gas from exhaust gas discharged from a combustion facility or the like and containing dust. The inlet 27 a is connected to the upstream side of the flue 1 of the combustion facility and the outlet 27 b is connected to the downstream side of the flue 1. The duct 27 is inserted in the middle of the duct 27 and the inner wall is substantially the same as the duct 27. The filter 28 includes a substantially cylindrical filter 28 having the same cross-sectional shape, and a cover 29 that covers the outside of the filter 28 and has a take-out port 29a for taking out the filtered exhaust gas.
[0024]
The duct 27 is inserted with a pump 30 for sucking exhaust gas containing dust from the flue 1 and forcibly discharging it into the flue 1.
[0025]
When this sampling apparatus is used in the SO ₃ concentration meter shown in FIG. 1, the suction port and the discharge port of the duct 27 are attached to the flue 1 after removing the suction pipe 3a and the filter 5 of the SO ₃ concentration meter. The extraction port 29a may be attached to the suction pipe 3b (in this case, two pumps 7 and 30 are used).
[0026]
According to this exhaust gas sampling device, since the filter 28 has a substantially cylindrical shape having substantially the same cross-sectional shape as the duct 27, there is little resistance to block the flow when dust-containing exhaust gas flows in the direction of the arrow 31 in the filter 28. Even if the dust 32 adheres to and accumulates on the inner wall of the filter 28, it is pushed by the flow of exhaust gas, so that it passes through the duct 27 again and returns to the flue 1 so that the filter 28 is hardly clogged. The SO ₃ gas in the exhaust gas sucked into the duct 27 passes through the filter 28 in the direction of the arrow 33 and is sent to the cavity 6 in the direction of the arrow 34 from the take-out port 29a formed in the cover 29.
[0027]
In addition, since a pump 30 for inserting exhaust gas into the duct 27 and forcibly discharging it into the flue 1 is inserted, the flow rate of exhaust gas flowing in the direction of arrows 35 and 36 in the duct 27 is increased. The dust 32 adhering to the filter 28 without being reduced is forcibly removed and discharged to the flue 1 so that the filter 28 is hardly clogged.
[0028]
【The invention's effect】
In short, according to the present invention, the following excellent effects are exhibited.
[0029]
It is possible to provide a sulfuric acid gas concentration meter capable of continuously measuring the sulfuric acid gas concentration in the exhaust gas.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing an embodiment of a sulfuric acid gas concentration meter according to the present invention.
FIG. 2 is a diagram showing the relationship between the composition of SO ₃ , the concentration of water, and the temperature.
FIG. 3 is a conceptual diagram of an exhaust gas sampling apparatus showing a modification of the filter used in the sulfuric acid gas concentration meter of the present invention.
4 is a view showing a state in which the exhaust gas sampling device shown in FIG. 3 is attached to a flue of a combustion facility.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Flue 5 Filter 6 Cavity 7 Pump 8a, 8b Transparent window 9 Light source 10 Spectroscope 11a-11c Reflection mirror 12 Photodetection element 14, 24 Temperature regulator 15 Heater 23 Preheating part 25 Arithmetic unit

Claims (4)

A sulfuric acid gas concentration meter for measuring the concentration of sulfuric acid gas in exhaust gas in a flue of a combustion facility or the like, comprising a suction pipe for sucking exhaust gas from the flue and a discharge pipe for discharging exhaust gas to the flue In addition, a cavity having two transparent windows facing each other, a preheating portion provided in the suction pipe for passing the temperature of the exhaust gas passing through the suction pipe to be 400 ° C. or more and 450 ° C. or less, and in the cavity A light source for irradiating light, a reflection mirror disposed outside the cavity and reciprocating the light from the light source into the cavity a plurality of times, and analyzing the light after the reciprocation in the exhaust gas A sulfuric acid gas concentration meter, comprising: a calculating means for calculating the sulfuric acid gas concentration of the gas. The sulfuric acid gas concentration meter according to claim 1, wherein a filter for removing dust in the exhaust gas is provided in the middle of the intake pipe. The sulfuric acid gas concentration meter according to claim 2, wherein a pump for forcibly discharging the exhaust gas in the cavity into the flue is provided in the middle of the discharge pipe. The sulfuric acid gas concentration meter according to claim 3, wherein a heater for heating the cavity is provided in the cavity.

Images