JPS5850004A - Oxygen concentration control device - Google Patents

Abstract

PURPOSE:To continue automatically a stable operation, by turning on a relay contact, which short-circuits the output terminal of a proportional plus integral and differential controller, when a disturbance is detected by a signal converter and setting the holding time of the turning-on by a timer. CONSTITUTION:Besides conventional devices, a sequence circuit 9 is provided between a signal converter 4 and a proportional plus integral and differential PID controller 6. In this circuit 9, a timer 9D is connected in series to a circuit which has relay contacts 9A, 9B, and 9C connected in parallel to the converter 4. This timer 9D is operated when one of contacts 9A, 9B, and 9C is turned on, and the timer 9D is held in the turn-on state for a prescribed time after the turned-on relay is turned off. When tie timer 9D is operated, a contact 9E which short-circuits the circuit between terminals led out from the controller 6 is turned on. Thus, the O2 concentration value for the disturbance is held, and an air supply quantity is held in a certain value.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an oxygen concentration control device (hereinafter referred to as an O2 concentration control device), and particularly relates to an O2 concentration control device that can supply a stable amount of air even when a disturbance occurs. Regarding equipment.

A conventional Ox 111 degree control device has a configuration as shown in FIG. That is, exhaust gas process line 1
In order to detect 02 in the exhaust gas, a glove 2 is attached to take out a portion of the exhaust gas. This probe has a configuration as shown in FIG. That is, the glove 2 has two gas suction holes provided in a part of a cylinder whose tip is closed. A transmitter 3 is attached to the glove 20, and a signal converter 4- is connected to the transmitter 3 as shown in FIG. A PID controller 6 is connected to the signal converter 4 via a filter 5 to adjust the 02 concentration in the exhaust gas. This PI
A function generator 7 is connected to the D controller 6. Also,
A calculator 8 is connected to this PID controller 6, and the amount of air to be supplied is adjusted by the calculator 8.

, Konoyori na O! In the concentration control device, probe 2, which is attached to process line 1 where exhaust gas is actually discharged, has two gas suction holes that are small, so soot, etc. in the exhaust gas causes blisters. . If this blistering occurs, it is purged by the method shown in FIG. That is, a separate system is connected to the transmitter 3 connected to the probe 2, and purge air can be inserted using three solenoid valves.

Therefore, when the probe 2 becomes clogged, the solenoid valve 3A is operated to insert purge air and remove the blockage.

If this purging is performed, excessive air will be inserted, so the transmitter 3 will detect the 02 concentration as an abnormal value, and the air supply amount will be controlled based on this 02 concentration, resulting in disturbance. Such a disturbance occurs both when the transmitter 3 for detecting the 02 concentration in the exhaust gas is down and when the sub-tube P is turned on. This suit blower uses steam in place of the air used during the purging process for reverse blowing.

In the event of such a disturbance, the conventional 02 concentration control device temporarily stops automatic control and switches to manual control.
As a guideline, the manual crystal power signal of the PID controller 6 was sent to the calculator 8, which made it impossible to control smooth automatic operation, and if there were gaps in the operator's operations, the operating efficiency would drop significantly. It had

The purpose of the present invention is to perform stable automatic control even when a temporary disturbance occurs.
When the 2 transmitter is down, when the glove is in reverse purging (so-called reverse purge), and when the suit is being operated, a disturbance signal is placed on the exhaust gas O2 concentration transmitter, which disrupts the control system and makes it impossible to operate safely. In order to prevent this from occurring, and also cause a decline in production efficiency, the idea was to temporarily hold a stable signal at that position before the disturbance to perform stable automatic control. It is.

Examples of the present invention will be described below.

FIG. 4 shows an embodiment of the invention.

In the drawings, the same reference numerals as in the conventional example shown in FIG. 1 indicate the same parts and the same functions. This embodiment differs from the conventional example shown in FIG. 1 in that a sequence circuit 9 is connected between the signal converter 4 and the PID controller 6. This Noken circuit 9 has a power source and a series relay contact 9A.

9B and 9C are connected in parallel, and a timer 9D is connected in series to these parallel circuits, which delays the instantaneous opening time by a predetermined time. This timer 9D is connected to the relay contact 9A.
, 9B, and 9C are turned ON, and has the function of maintaining the ON state for a predetermined period of time even after the relays 9B and 9C are turned on. When the timer 9D is activated, a contact 9E that short-circuits the terminals of the PIDll1 meter 61 is turned on. By turning on this relay contact 9E, the 02 concentration value at the time of disturbance is held, and the amount of supplied air is maintained at a constant value. Note that the relay contact 9A is connected to the transmitter 3.
The relay contacts 9B and 9C are designed to operate when the machine goes down, and the relay contacts 9B and 9C operate when the gear is in reverse gear and suit gear, respectively.

Therefore, the signal converter 4 detects the exhaust gas O, the signal converter 4 detects the signal converter 4, and immediately the output signal of the exhaust gas 02 PID 111 meter becomes DOWN, or the signal before receiving the reverse blow signal. The position is temporarily held, and the signal is supplied to the computing unit 8 to automatically continue stable operation. This control operation is also performed at the time of the suit blower, which is performed periodically.

It should be noted that in the sequence circuit 9 of this device, it takes some time for the disturbance signal to return and for the process disturbance to settle down in the next state, so by adding a delay timer control circuit during that time, the output signal of the exhaust gas PID controller 6 is adjusted to that position. Extend with hold to stabilize control. Also exhaust gas O, PID controller 6
By incorporating a reset windup mechanism similar to that of a pan press, it is possible to synchronize with the output hold signal and perform stable control.

Although this device is an electric signal control circuit, when it is an air signal control circuit, the present invention can be applied to all operation signals by replacing the corresponding equipment.

Therefore, according to this embodiment, the 02 concentration control can be performed automatically and stably, and can be controlled without changing the operating parameters, resulting in less wasteful fuel consumption and energy saving. Connect.

As described above, according to the present invention, stable automatic control can be performed even if a temporary disturbance occurs.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a conventional oxygen concentration control device, FIG. 2 is a configuration diagram of the glove shown in FIG. FIG. 4 is a circuit diagram showing an embodiment of the present invention. 2...Probe, 3...Combiner, 4...Signal converter, 61 z Port Figure 3

Claims (1)

[Claims] 1. A probe that takes in exhaust gas, a transmitter that sends a signal based on the concentration of oxygen in the exhaust gas that is taken in by the viewing probe, and a signal converter that converts the signal into a predetermined signal. A filter that removes noise, a PID controller that adjusts oxygen in exhaust gas, a function generator, and a calculator that adjusts the air supply amount to maintain the oxygen concentration of exhaust gas at a constant value. The oxygen concentration control device includes: a first means for detecting a disturbance; a second means for holding an air amount according to an oxygen concentration at the time of detecting the disturbance when the disturbance is detected by the first means; An oxygen concentration control device comprising: third means for determining the hold time of the second means. 2. In the invention set forth in claim 1, the hold time of the third means is the time from the occurrence of the disturbance to the end of the disturbance plus a predetermined time until stabilization. Characteristic oxygen concentration control device. 3. The oxygen concentration control device according to claim 1, wherein the third means is a timer having a delay time for opening, which is activated by a relay activated by disturbance detection.