JPS62145137A - Analyzing device for incineration gas - Google Patents

Abstract

PURPOSE:To prevent the corrosion without changing a piping and the machine quality of an equipment, etc., and also to measure exactly an incineration gas component, by diluting an incinerator exhaust gas brought to sampling, by the dry gas of a prescribed flow rate. CONSTITUTION:Dry air from an instrument air system 10 is fed to an instrument piping 2 through a dust removing part 11, a pressure regulating part 12, a flow rate adjusting part 13, an instrument air temperature control part 14, and an instrument piping 15, and a sampling gas from an incinerator 1 is diluted in a prescribed ratio by the dry gas. Thereafter, the sample gas is fed to a filter catching part 5 through an exhaust gas temperature control part 3, radioactive particles contained in an incineration exhaust gas are caught continuously, and a radiant ray is measured by a radiation measuring part 4. Next, the sample gas from the filter catching part 5 is fed to an instrument piping 9 through a flow rate adjusting part 6 and a sample pump 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an incineration gas analyzer, and particularly to an incineration gas analyzer suitable for exhaust gas containing corrosive gas.

[Conventional technology]

As described in Japanese Patent Application Laid-Open No. 57-66398, conventional devices have been designed to prevent corrosion of the exhaust gas filter by hydrogen chloride by mixing cooling air. However, no consideration was given to preventing corrosion of the incineration gas analyzer.

[Problem that the invention seeks to solve]

The problem with the conventional method is that the incinerator exhaust gas contains corrosive gas components, and as the gas temperature drops, it becomes a drain, causing pinholes in piping and malfunctions due to tar adhesion to flow rate regulating valves. A problem has occurred, which is interfering with continuous measurement. The current device is used to prevent sample gas from liquefying.

Instrumentation piping and a heater in the analyzer have been installed to control the temperature of the sample gas. Heater control should be carried out at approximately 55°C because, for example, the upper limit of operating temperature for radiation detectors, etc. is approximately 60°C, and the dew point of incinerator exhaust gas is approximately 50°C (design value). ing. On the other hand, the incinerator exhaust gas components change depending on the combustion materials, and it is thought that this causes a temporary increase in corrosive gas components and a rise in the dew point, leading to the above-mentioned problems. As a countermeasure to the problem, the first thing to consider is to change the materials of piping and equipment to corrosion-resistant materials. As a corrosion-resistant material,
Titanium, FRP, and Teflon coated materials are well known, but Teflon coated material is the best when evaluating workability, temperature resistance, etc. However, it is difficult to use Teflon coating material for all piping and equipment, and at the current technological level, it is difficult to coat Teflon coatings on flow rate regulating valves and sample pumps.

An object of the present invention is to prevent corrosion without changing the nature of piping and equipment, and to accurately measure incineration gas components.

[Means for solving problems]

The above objective is achieved by diluting the sampled incinerator exhaust gas with a constant flow of dry gas. That is, corrosion suppression is effective by lowering the relative temperature in the sample gas as much as possible and by reducing the absolute amount of corrosive gas components in the sample gas as much as possible. First, in order to lower the relative temperature in the sample gas, the sample gas must be dehumidified. For example, if the measurement item is radioactive particles, iodine, or a gas that is easily liquefied, dehumidification will cause the object to drain. will be moved to. Therefore, regarding the above measurement items, directly dehumidifying the sample gas will cause errors in the measured values at the subsequent stage. Furthermore, it is necessary to correct the amount of material transferred into the drain by manual analysis, etc., which deviates from the purpose of continuous measurement.

Next, in order to reduce the absolute amount of corrosive gas components, the amount of sample gas must be reduced to an extent that does not interfere with the measurement ability of the analyzer. Since the exhaust gas analyzer samples a constant flow rate, the amount of sample gas will be reduced and the remaining amount will be supplemented with gas that does not contain corrosive gases. As for the supplementary gas, a controlled gas that does not affect the analysis items in the gas analyzer is suitable. A controlled gas is suitable if the gas components are clear, the particle size contained in the gas is as small as possible, and the gas is dehumidified.

Therefore, nitrogen gas or the like (approximately 100%) is suitable as the supplementary gas, but the supply method using a cylinder is not possible in an apparatus that requires continuous measurement because the cylinder capacity is limited.

In nuclear couplants, etc., there is a system that supplies compressed air necessary for operation control and maintenance of each system that makes up the equipment. There is. Instrument air is characterized by very low relative humidity (approximately 0.26%) and by the fact that it does not contain particles larger than approximately 5 μm. For example, one analysis item is
Instrument air can be used as a supplementary gas to collect radioactive particles and measure radiation.

[Effect]

Reducing the sampling flow rate of the incineration gas to a constant flow rate will reduce the absolute amount of corrosive gas components introduced into the gas analyzer.

Mixing the sample gas with a constant flow of dry gas is
This indirectly works to lower the relative humidity of the sampling gas. As a result, the sample gas brought into the gas analyzer may be under conditions that make it difficult to corrode. In gas analyzers.

Since the amount of sampling gas is diluted with dry gas at a constant ratio, the total amount is il! It is necessary to simply add a certain correction to the l value.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. This example is a system that measures radiation while continuously collecting radioactive particles contained in incineration exhaust gas. The sensitivity of the detector in a radiation measurement device is a general target value (
The actual value of the detector is more than 10 times better than the designed value. Therefore, compared to the conventional sampling gas amount of 1, the sampling gas amount was set to 1/10, and 9/1
By setting 0 to be the amount of dry gas, the total amount of sampling gas in the radiation measuring device is set to 1. As a result, the absolute amount of corrosive gas components is reduced by a factor of 10, and the dry gas effectively lowers the relative temperature. In other words, the corrosion progression rate is based on the conventional rate.
It can be seen that according to the present invention, it is at least 1/10 or less. This is considered to provide a design with considerable leeway for increases and decreases in corrosive gas components due to changes in the incinerated material. In FIG. 1, instrumentation air is used as the drying gas. Regarding instrument air, various considerations are made as shown below.

First, since it contains particles of about 5 μm, a dust removal section with the same size as a filter in a radiation measurement device is installed, and a pressure adjustment section is installed due to fluctuations in usage load in other systems, and the sample gas and instrumentation air are constantly mixed. A flow control unit has been installed to control the temperature of the sample gas, and an instrumentation air temperature control unit has been installed to eliminate the temperature difference between the sample gas temperature and the instrumentation air.

FIG. 2 shows a conventional radiation measurement system.

〔Effect of the invention〕

According to the present invention, it is possible to prevent malfunctions due to corrosion of the incineration gas analyzer, and it is possible to continuously monitor incinerator exhaust gas. Conventionally, problems due to corrosion would occur approximately six months after the facility was put into operation, and even after restoration, the problem would occur again, hindering the operation of the incineration facility.

By reducing the sample amount of exhaust gas, the absolute amount of corrosive gas components is reduced, and by mixing dry air and keeping the total sample gas flow rate constant, indirectly the relative amount of corrosive gas components in the sample gas is It will reduce humidity,
This has the effect of reducing factors that promote corrosion. Therefore, the operation of the incineration equipment is made smooth, and the maintainability of the incineration gas analyzer is sufficiently improved.

Brief Explanation of Concave Surface FIG. 1 is a schematic diagram of a radiation measurement system according to an embodiment of the present invention, and FIG. 2 is a schematic diagram of a conventional radiation measurement system I\.

Claims (1)

[Claims] 1. An incineration gas analyzer characterized in that an exhaust gas analysis system comprising an instrumentation pipe and an incineration gas analyzer is provided with a dilution device using dry gas.