JP2000146984A - Continuous analyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a defective measurement during the calibration, the failure or the periodic inspection of a continuous analyzer. SOLUTION: A plurality of analysis parts 1, 2 are used. Their input sides are connected respectively to a common port 6c at a flow-passage selector valve 6 and to a common port 7c at a flow-passage selector valve 7. An input port 6a and an input port 7a are connected to an introduction pipe 12. An input port 6b is connected to a flow-passage opening and shutting valve 8 in a calibration-gas flow passage, and an input port 7b is connected to a flow- passage opening and shutting valve 9 in a calibration-gas flow passage. When the output A of the analysis part 1 and the output B of the analysis part 2 are input to a computing and control part 3, the computing and control part 3 controls the outputs so as to become 0.5(A+B) while the analysis parts 1, 2 are performing a measurement normally, it controls the outputs so as to become B while the analysis part 1 stops a measurement, and it controls the outputs so as to become A while the analysis part 2 stops a measurement. Thereby, a continuous and normal output signal can be obtained even during the calibration the failure or the periodic inspection of a continuous analyzer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous analyzer for continuously measuring the components of ambient air and flue gas.

[0002]

2. Description of the Related Art Atmospheric analyzers for measuring harmful substances such as nitrogen oxides, sulfur dioxide, and carbon monoxide in the ambient atmosphere or at their sources need to be continuously and continuously measured for the purpose. Conventionally, a spare analyzer is prepared in order to prevent the measurement from being interrupted when the analyzer fails, and when the analyzer in use is interrupted due to a failure or the like, switching to the output side of the spare analyzer is performed. Therefore, a method of minimizing missing measurement (interruption of measurement for a certain period) has been adopted. In addition, the concentration to be measured has been reduced due to the development of environmental protection technology, and it has been required to measure the low concentration more accurately.

[0003]

In the conventional method, if a used analyzer breaks down, it must be confirmed and then manually switched to a spare analyzer. Since the measurement is interrupted in the cycle of, missing measurement cannot be prevented. In addition, in order to shorten the missing time due to a failure, a spare analyzer and its replacement parts must be provided at all times, and a continuous monitoring service system must be maintained, resulting in a large cost. In addition, due to the development of harmful substance reduction technology, analyzers are required to measure with higher accuracy even at low concentrations.However, since characteristic deterioration such as drift that occurs in the analyzer being used is output as it is, high There was a problem that the accuracy could not be measured.

[0004] The present invention has been made in view of such circumstances, and does not cause a missing measurement even during a failure, calibration, or periodic inspection (hereinafter abbreviated as regular inspection) of an analyzing unit in use. It is intended to provide a continuous analyzer.

[0005]

In order to achieve the above object, a continuous analyzer according to the present invention comprises a plurality of analyzers, a flow path switching mechanism for independently performing calibration, and a flow path switching mechanism. A calibration gas cylinder and a channel opening / closing mechanism for sending a calibration gas through the mechanism, and an output signal of the analyzer are taken in, and all analyzers perform averaging during normal measurement, and analyzers during measurement suspension. The present invention is characterized in that it is provided with arithmetic control means for using the output of the analyzer during normal measurement as an output signal except for the output of the analyzer, and a display output unit for displaying and outputting the output of the analyzer.

[0006] The continuous analyzer of the present invention is configured as described above, and by using this, it is possible to perform continuous analysis without any failures during use or during calibration or regular inspection.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The continuous analyzer of the present invention will be described in detail below with reference to FIGS. FIG. 1 is a schematic configuration diagram of an embodiment of the present continuous analyzer, and FIG. 2 is a block diagram (a) of operation control in an operation controller of the continuous analyzer and a state diagram (b) of a measurement mode. 3 is an output characteristic diagram of the continuous analyzer, FIG. 4 is a flowchart for explaining a measurement procedure of the continuous analyzer, and FIG. 5 is a flowchart showing a part of a calibration procedure.

As shown in FIG. 1, the present continuous analyzer has an independent analyzing section 1 and an analyzing section 2, and the input side of the analyzing section 1 is connected to a common port 6 c of the flow path switching valve 6 and to the analyzing section 2. Is connected to a common port 7c of the flow path switching valve 7. Also,
The input ports 6a and 7a of the flow path switching valves 6 and 7 are connected to the sample gas introducing pipe 12, and the input ports 6b and 7b are connected to the flow path opening / closing valve 8 and the span for opening and closing the zero calibration gas flow path from the zero calibration gas cylinder 10. It is connected to a flow path opening / closing valve 9 that opens and closes a span calibration gas flow path from the calibration gas cylinder 11.

On the other hand, the output signal A of the analyzer 1 and the output signal B of the analyzer 2 are input to the arithmetic and control unit 3. The arithmetic control unit 3 reads the program written in the memory 5 from FIG.
The operation contents shown in the operation block 13 of the operation control block diagram of FIG. 7A are taken in, and the output signals A and B of the analysis units 1 and 2 are added and averaged. Arithmetic block 13
Are scalers 13a and 13b for correcting zero and span each time the analyzers 1 and 2 are calibrated, an adder 13g for adding their outputs, and the outputs of the scalers 13a and 13b and the adder 1
3g and switches 13c to 13f for connecting to 3g and a coefficient unit 13h for multiplying the addition result by a coefficient of 0.5. Tc to Tf in the drawing are contact symbols of the switches 13c to 13f, and the ON / OFF state is determined by the measurement mode of the analyzers 1 and 2 as shown in FIG. According to this measurement mode, the following arithmetic expressions (a), (b), and (c) are selected. (A) indicates that Tc and Tf are ON and Td and Te are OFF when the analyzers 1 and 2 are performing normal measurement.
Thus, the arithmetic expression X is X = 0.5 (A + B). In (b), X = B only during the measurement suspension due to failure, calibration or regular inspection of the analysis unit 1 only. In the case of (3), only the analysis unit 2 becomes X = A during the suspension of the measurement as in the case of the item (2).

The calculated data calculated according to the measurement mode as described above is sent to the display / output unit 4. The display / output unit 4 has a function of performing digital processing such as smoothing on input data, then performing screen display and print recording, and outputting a digital signal or an analog signal. FIG. 3 shows output characteristics of the output of the analyzer 1, the output of the analyzer 2, and the final output of the continuous analyzer. In this case, continuous output signals can be obtained by using the analysis units 1 and 2 having the same performance. Assuming that the individual error of the analysis units 1 and 2 is e, the total error of the final output is about 0.7e, and the accuracy and stability are relatively improved.

Normally, the calibration is automatically performed based on a program written in the memory 5. As shown in FIG. 3, the calibration periods of the analyzer 1 and the analyzer 2 are set so as not to overlap. During this calibration period, a control signal is sent from the control block 14 to the switches 13c to 13f, the flow path switching valves 6, 7 and the flow path opening / closing valves 8, 9 of the operation block 13 of the operation control section 3. Hereinafter, the measurement procedure will be described with reference to the flowchart of FIG.

When the continuous analyzer is operated (started), the arithmetic and control unit 3 sequentially repeats the processing of steps (S1) to (S6). In (S1), it is checked whether or not the analysis unit 1 is out of order.
Proceeding to 2), if a failure occurs, only the output B of the analysis unit 2 is output, and the processing of (S1) is repeated. If the failure of the analysis unit 1 is completed and the operation is restarting, the process proceeds to (S2). In (S2), it is checked whether or not the analysis unit 2 is out of order. If not, the process proceeds to step (S3). If it is out of order, only the output A of the analysis unit 1 is output, and the process returns to (S1). . If the failure of the analysis unit 2 has been repaired and restarted, the process proceeds to (S3).
In (S3), it is checked whether the analysis unit 1 is calibrating. If calibration is not being performed, the process proceeds to step (S4). If calibration is being performed, only the output B of the analysis unit 2 is output, and the process returns to (S1). .
When the calibration of the analyzer 1 is completed, the process proceeds to (S4). (S4)
Then, it is checked whether the analysis unit 2 is performing calibration. If calibration is not being performed, the process proceeds to step (S5). If calibration is being performed, only the output A of the analysis unit 1 is output, and the process returns to step S1. When the calibration of the analyzer 2 is completed, the process proceeds to (S5). In (S5), it is checked whether the analysis unit 1 is performing the regular inspection. If the regular inspection is not being performed, the process proceeds to step (S6). If the regular inspection is being performed, only the output B of the analysis unit 2 is output. Return to processing. When the regular inspection of the analyzer 1 is completed, the process proceeds to (S6). In (S6), it is checked whether the analysis unit 2 is performing the regular inspection. If the regular inspection is not being performed, the outputs A and B of the analysis units 1 and 2 are averaged and output, and the process returns to (S1). If the analysis unit 2 is performing the regular inspection, only the output A of the analysis unit 1 is output, and the process returns to (S1). When the regular inspection of the analyzer 2 is completed, the outputs A and B of the analyzers 1 and 2 are added and averaged and output, and the process returns to (S1).

In the above-mentioned fault, the output of the scaler 13a and the output of the scaler 13b are
j, if the difference is within a certain tolerance, both analyzers are normal, and if the difference exceeds a certain tolerance, a sudden change, large drift or no change It can be determined that the analysis unit that matches the predetermined failure pattern has failed. Also,
By monitoring signals from the temperature sensor, pressure sensor, flow rate sensor, and the like attached to the analysis unit, and transmitting a failure signal from the analysis unit to the operation control unit 3, the operation control unit 3 can perform the above-described failure. May be performed.

FIG. 5 is a flowchart showing a calibration procedure.
It is programmed in advance and stored in the memory 5. For example, when performing zero calibration of the analysis unit 1, the arithmetic control unit 3
The input port of the flow path switching valve 6 is switched to the side 6b by the control signal from the control block 14 of FIG.
Is opened to supply the zero calibration gas to the analysis unit 1. Zero output is adjusted by matching the output at this time with the 0% output of the scaler 13a in the arithmetic and control unit 3. Next, the flow path opening / closing valve 8 is closed, and the input port of the flow path switching valve 6 is switched to the side 6a to complete the zero calibration. During this time, the steps (S
In 3), a digital signal indicating that calibration is in progress is sent. When the span calibration of the analysis unit 1 is performed, the input port of the flow path switching valve 6 is switched to the side 6b by the control signal from the arithmetic control unit 3, and then the flow path opening / closing valve 9 is opened to analyze the span calibration gas. Supply to unit 1. Span calibration is performed by matching the output at this time with the 100% output of the scaler 13a in the arithmetic and control unit 3. Next, the flow path opening / closing valve 9 is closed, and the input port of the flow path switching valve 6 is switched to the side 6a to complete span calibration. The calibration of the analyzer 2 is performed in the same manner using the flow path switching valve 7. This program starts at the same time as the operation of the continuous analyzer, and is executed in conjunction with the measurement flowchart shown in FIG.

If the start time and end time data of calibration and regular inspection are input to the arithmetic and control unit 3 using a setting input device (not shown) while the continuous analyzer is in operation, it is determined in advance by a program. It is also possible to additionally execute the calibration and the regular inspection.

Further, as a modified example of the present invention, a bypass mechanism for outputting the output of the analysis unit 1 or 2 as the final output when the operation control unit fails may be provided, thereby further improving the reliability. it can.

[0017]

The continuous analyzer of the present invention is configured as described above, and has the following effects. (1) Normal 2
Since the outputs of the analyzers are averaged and output, zero and span drift are reduced as compared with the use of only one analyzer.
(2) Instruction noise is also reduced by averaging one term.
(3) Even if a failure occurs due to the execution of the measurement program, the other analysis unit instantaneously backs up the data, thereby preventing missing data and increasing reliability. (4) The analyzer under calibration or regular inspection is excluded by the arithmetic and control unit, and during that time, the other analyzer automatically backs up, so that there is no measurement interruption. (5) Since there is no missing measurement during calibration, the calibration cycle can be shortened and the calibration gas can be flown, and early failure judgment can be made from the drift during that period.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a continuous analyzer of the present invention.

FIGS. 2A and 2B are a calculation control block diagram (a) and a measurement mode state diagram (b) used in a calculation control unit of the continuous analyzer.

FIG. 3 is an output characteristic diagram of the continuous analyzer.

FIG. 4 is a flowchart showing a basic measurement operation of the continuous analyzer.

FIG. 5 is a flowchart showing the calibration time and calibration contents of the continuous analyzer.

[Explanation of symbols]

 1, 2 ... analysis unit 3 ... calculation control unit 4 ... display / output unit 5 ... memory 6, 7 ... flow path switching valve 6a, 6b, 7a, 7b ... input port 6c, 7c: Common port 8, 9: Flow opening / closing valve 10: Gas cylinder for zero calibration 11: Gas cylinder for span calibration 12: Introductory pipe 13: Operation block 13a, 13b ..Scalers 13c, 13d, 13e, 13f... Switches 13g... Adders 13h... Coefficient units 13j... Comparators 14... Control blocks

Claims (1)

[Claims] A plurality of analyzers, a channel switching mechanism for independently performing calibration, a calibration gas cylinder and a channel opening / closing mechanism for sending a calibration gas through the channel switching mechanism, Capture the output signal of the analyzer, perform averaging while all analyzers are performing normal measurement, and remove the output of the analyzer during normal measurement as an output signal, excluding the output of the analyzer during measurement interruption, if any. And a display output unit for displaying and outputting the output of the analysis unit.