JPS5823884B2 - Ammonia gas analyzer with furnace emergency protection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ammonia gas analyzer.
In particular, it relates to an ammonia gas analyzer equipped with a reactor emergency protection device.

In recent years, an ammonia reduction method has been widely used as a technology for removing nitrogen oxides from various combustion furnace exhaust gases and preventing air pollution.

The nitrogen oxide removal device using the ammonia reduction method is equipped with an ammonia gas analyzer for monitoring to prevent unreacted ammonia from flowing out.

The commonly used ammonia gas analyzer is
Because it uses the so-called NHa oxidation and NO2 reduction method, which converts NH8 and NO2 into NO under a high-temperature catalyst, the NHa oxidizer and NO2 reducer each have a temperature of about 00°C.
to about 800°C and from about 00°C to about 500°C.

Furthermore, in order to prevent sampling loss caused by the reaction of NH8 with SOa, there is It is heated above the reaction equilibrium temperature of SOa (approximately 300°C).

That is, the probe itself is heated by a glove heater, and the sample line is heated by a line heater.

However, the ammonia gas analyzer with the above configuration,
If an abnormality were to occur in the combustion furnace and unburned hydrocarbons were generated within the furnace, an extremely dangerous situation would result.

In other words, since the ammonia gas analyzer, which is maintained at an extremely high temperature from the probe to the inlet of the NHs oxidizer, is directly connected to the inside of the furnace, the unburnt hydrocarbons can ignite, which can destroy the furnace and cause work to be carried out. This would put the person in an extremely dangerous situation.

Therefore, the main object of the present invention is to provide an ammonia gas analyzer equipped with a furnace emergency protection device and capable of guaranteeing the safety of the furnace in the event of a furnace failure.

An object of the present invention is to provide a furnace emergency protection device that is equipped with a heater power cutoff means, an exhaust gas inflow cutoff means provided at a connection part with the furnace, and a N2 gas supply means, and is extremely reliable and ensures the safety of the furnace. It is an object of the present invention to provide an ammonia gas analyzer that can be fully guaranteed.

Next, the ammonia gas analyzer with a furnace emergency protection device according to the present invention will be described in detail with reference to the drawings.

Referring to FIG. 1, a typical conventional ammonia gas analyzer is depicted.

The probe 2 of the ammonia gas analyzer is inserted through the furnace wall 4 to detect nitrogen oxides (NO2 and N2) generated in the furnace.
o) and the exhaust gas G containing NHa is collected.

The globe 2 is usually made of a metal tube, and an electric probe heater 6 is provided around the circumference of the globe 2, which is heated to a temperature higher than the reaction equilibrium temperature (approximately 300° C.) of SOa and NH8 in the exhaust gas G to be collected.

Exhaust gas G collected via probe 2 and heated
is fed into a filter means 8 arranged as required.

Providing the filter means 8 has the advantage of removing dust from the exhaust gas.

A metal filter 10 is provided within the filter means 8 to remove dust in the exhaust gas G.

The filter means is also heated and kept warm at 300° C. or higher by a heating means (filter heater) 12.

The exhaust gas G from which dust has been removed is introduced into the converter 16 via a line (pipe line) 14 .

The line 14 that transfers the sample exhaust gas G is also equipped with heating means, so that the components in the sample do not chemically react within the pipe.
A line heater 18 is provided and configured to keep the inside of the line at a constant temperature.

The flow path of the sample exhaust gas G introduced into the converter 16 is branched into two flow paths 20 and 22.

The sample exhaust gas G flowing into one flow path 20 is the first NO.
2 flows into the reducer 24, and all NO2 in the exhaust gas is converted into NO2.
and is introduced into the first analyzer 36 via the flow path 26.

The sample exhaust gas G that has flowed into the other flow path 22 flows into the NHa oxidizer 28, where the NHa in the exhaust gas is converted to NO, and then the exhaust gas G is led to the second NO2 reducer 32 via the flow path 30. All of the NO2 in the exhaust gas is converted to NO.

N by the NHa oxidizer 28 and the second NO2 reducer 32
The sample exhaust gas G in which all Ha and NO2 have been converted to No is introduced into the second analyzer 38 via the flow path 34.

The NHa oxidizer 28 is heated to 700°C, and the NO2 reducers 24 and 32 are heated to 400°C by converter heaters 40, respectively.

By comparing the measured values of the first and second analyzers 36 and 38, the concentration of NHa is determined.

Referring to FIG. 2, an embodiment of an ammonia gas analyzer with a furnace emergency protection device according to the present invention is schematically illustrated.

The ammonia gas analyzer according to the present invention is basically completely the same as the conventional ammonia gas analyzer shown in FIG. ing.

The ammonia gas analyzer according to the present invention is structurally significantly different from conventional analyzers in that (1) an N2 gas supply port 3 is provided so that N2 gas can be supplied to the probe 2; (2) A shutoff valve 7 is disposed between the probe 2 and the converter 16, preferably the filter means 8; (3) The probe heater 6, the filter heater 12, the line heater 18, the converter heater 40, etc. The point is that the heating means is connected to the power cutoff circuit 50.

That is, in the ammonia gas analyzer according to the present invention, N2
It differs greatly from conventional analyzers in that it is equipped with a furnace emergency protection device that includes a gas supply means, a sample exhaust gas cutoff means, and a heater power cutoff means provided between the furnace and the analyzer.

The operation of the ammonia gas analyzer according to the present invention will be explained in detail.

A furnace emergency circuit 100 is provided in various combustion furnaces.
For example, abnormally low flue gas pressure, abnormally low fuel gas pressure,
In the event of an abnormal drop in steam pressure, power failure, etc., the furnace emergency circuit activates and generates an emergency signal.

In particular, even when there is a possibility that the furnace is filled with unburned gas, the furnace emergency circuit is activated and generates an emergency signal.

The signal is transmitted to the reactor emergency protection system. The emergency signal from the furnace emergency circuit 100 is transmitted to the globe heater 6, filter heater 12, line heater 18, and converter heater 4.
0 and the power supply 108 of the cutoff valve heater 9 are cut off, and the supply of electricity to each heater is stopped.

At the same time, the solenoid valve 110 is operated to close the shutoff valve I.

As a result, the flow of the sample exhaust gas G from the probe 2 to the filter 8 is completely blocked.

Furthermore, the emergency signal from the reactor emergency circuit 100 is sent to the solenoid valve 10.
2 is opened, and the N2 gas from the N2 gas reservoir 104 is transferred to the pipe 10.
6 to the probe 2ON2 gas supply port 3, through which the probe 2 is discharged into the combustion furnace or into the flue.

As a result, not only the probe 2 but also the probe heater 6 provided around the probe 2 are rapidly cooled.

In addition, since the N2 gas fills the inside of the probe 2 and flows, it completely fluidly seals the communication part between the shutoff valve 7 and the probe 2, and in the event that the N2 gas enters the inside of the probe 2 from inside the furnace. Exhaust gas is also completely shut off at the front of the shutoff valve 7, and furthermore, exhaust gas is completely prevented from entering the filter means 8 and the converter 16.

Therefore, in the ammonia gas analyzer according to the present invention, when an abnormality occurs in the furnace and the furnace emergency circuit is activated, the furnace emergency protection device is activated, quickly cooling the high temperature probe portion protruding into the furnace, and By blocking the flow of exhaust gas from flowing into the analyzer, the furnace and analyzer can be protected and safe.

In the above description, the ammonia gas analyzer with a furnace emergency protection device according to the present invention was applied to a combustion furnace to analyze flue gas, but this device is also applicable to automobile exhaust gas,
It will be appreciated that the present invention can be effectively applied when analyzing effluent gas from an ammonia synthesizer and various other ammonia-containing gases.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a conventional ammonia gas analyzer. FIG. 2 shows an ammonia gas analyzer equipped with a furnace emergency protection device according to the present invention. 2...Glove, 3...N2 gas supply port, 4...Furnace wall, 6...Probe heater, 7
...Shutoff valve, 8; ...Filter means,
9...Shutoff valve heater, 12...Filter heater, 14...Line, 16...Converter, 18...Line heater, 24,32...・
...NO2 reducer, 28...N) (8 oxidizer, 36.38...Nitrogen oxide analyzer, 40.
...-Converter heat 1, 50...Power cutoff circuit, 100...Furnace emergency circuit, 102,1
10... Solenoid valve, 108... Heater power supply.

Claims (1)

[Claims] 1. A sample exhaust gas sampling probe; a converter equipped with an NHs oxidizer and a NO2 reducer for converting NHatN02 in the sample exhaust gas into No; measuring No from the converter and determining the concentration of NH8; An ammonia gas analyzer equipped with a nitrogen oxide analyzer for measurement, further configured to be activated in the event of a furnace emergency, (1) N2 gas supply means for supplying N2 gas to the probe;
(2) flow path blocking means for blocking a sample exhaust gas flow path between the probe and the converter; heater power cutoff means for disabling at least the heaters of the probe, the converter, and the flow path blocking means; An ammonia gas analyzer characterized in that it is equipped with a furnace emergency protection device. 2. A filter means is disposed between the probe and the converter, the flow path cutoff means of the reactor emergency protection device is a shutoff valve, and the filter means is disposed between the probe and the filter means. Ammonia gas analyzer described in Section 1.