JPS63286753A - Measuring instrument for particle concentration in sample gas - Google Patents

Abstract

PURPOSE:To easily measure the concentration of a contained particle by constituting the titled device so that a voltage is applied to a conductor for forming a collecting electrode, a current is allowed to flow and the particle concentration is measured by a variation quantity of the current, and also, the adhering particle is burned and removed. CONSTITUTION:Between a discharge electrode 1 being a cathode and a collecting electrode 2 being an anode, a high DC voltage is applied, a corona discharge is executed by applying a high voltage electrostatic field to sample gas, gas in the vicinity of the discharge electrode 1 is converted to a corona and a particle is electrified to negative, by which the particle is allowed to adhere to the collecting electrode 2. Thereafter, a conductor 4 being parallel to the collecting electrode 2 is connected to a power source 7 through changeover switch mechanisms 5, 6, and the concentration of an adhering particle is measured. In this case, if the adhesion quantity of the particle exceeds some extent, the measurement becomes impossible, therefore, a current is fed to the conductor 4 from a power source 8 and it is burned in red heat and regenerated. In such a way, the concentration is measured from a ratio of the variation quantity of the current per unit time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for measuring the concentration of particles in a sample gas.

[Conventional technology]

Conventionally, various types of devices for measuring particle concentration in gas have been known, but none are known in which a dust collection electrode is configured as a mechanism for burning off adhering particles as in the present invention.

In a particle concentration measuring device, it is desired to quickly and easily remove particles attached to a discharge portion for the next measurement, but no such device has been proposed to date.

[Means for solving problems]

This invention uses the principle of dust collection by an electrostatic precipitator to attach particles to an anode, which is a dust collection electrode, and forms the dust collection electrode with a set of two parallel electric wires. A voltage is applied between them, a current is applied, the current is measured, and the amount of attached particles is measured from the amount of change. This method has the disadvantage that it becomes impossible to measure when the amount of attached particles reaches a certain amount, but in the present invention, the electric wire of the dust collection electrode is further configured with a heating wire,
This problem was solved by burning the adhering particles, regenerating the dust collection function, and making it possible to measure the amount of adhering particles again.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to the drawings. The overall structure consists of a discharge electrode (cathode) to which a high voltage is applied, and a flat or curved dust collection electrode (cathode) provided opposite to the discharge electrode.
anode).

FIG. 1 shows a case where the dust collection electrode is planar and the discharge electrode is needle-shaped with its tip facing this plane.

In the figure, reference numeral 1 denotes a discharge electrode, which is made of a single needle-shaped metal wire installed vertically. Reference numeral 2 denotes a dust collecting pole, in which conducting wires 4.4 consisting of two heating wires are laid in parallel to each other in a spiral or other suitable shape on an insulating flat plate 3 provided horizontally. In addition to being used as dust collecting poles, these conductive wires 4.4 are also used as two changeover switch mechanisms 5 which are connected to each other by a continuous rod and operate simultaneously, as shown in FIG.
．． 6, the power source 7 and the heating power source 8 are alternately switched,
In this way, it is used as a substrate when the particle concentration is 8111 constant and combustible particles are removed. That is, as shown in FIGS. 3(A) to 3(D), the conductive wires 4.4 are bent in a wavy manner parallel to each other on the upper surface of the insulating flat plate 3 (FIG. 3(A)). Those that are parallel to each other and bent in a thin spiral shape ((B) in the same figure), those that are parallel to each other and have a concentric shape with a part cut out ((C)), and those that are parallel to each other and are completely bent. are formed into many parallel lines (Fig. 4 (D)), and the tips and ends of these conductors 3.3 are shown in Fig. 4 (A).
As shown in ~(D), they are connected to two sets of terminals aTcTbTd attached to the peripheral edge of the insulating flat plate 3 via lead wires, and in FIG. When both terminals are moved to the left side of the figure, the conductors 4.4 between terminals a, b, c, and d are connected to both ends of the power supply 70, respectively, and the current judger 9.4 connected to the ammeter A is connected. The amount of particles between the conductor wires 4 and 4 can be measured using the degree calculator 10, and if the tips of the changeover switch mechanisms 5 and 6 are moved to the right side of the figure, the terminals a, b and The conductive wires 4.4 between the terminals c and d together form a heating circuit that connects both ends of the power source 8, making it possible to remove combustible particles.

Now, in FIG. 1, the discharge electrode 1 is simply a single needle-shaped thing, and is simply connected to the high voltage power supply 12 via the changeover switch 11, but in FIG. A case is shown in which the electrode 1 also has a structure capable of burning combustible particles attached to its tip. In other words, the discharge electrode 1 connects the heating wire to V
It is bent into a letter shape and is connected to the high-voltage power source 12 via the changeover switch 11, and the heating power source 1 is connected to both ends of the V-shaped opening via the switch 13.
4, and both switches 11 and 13 are linked so that only one of them can be operated at any time.

Next, FIG. 6 shows a case where the discharge electrode is a single line and the dust collecting electrode is a curved surface surrounding it. The dust collecting electrode 2 has a shape in which a large number of conducting wires 4 made up of heating wires are arranged in parallel along the axial direction on the inner surface of one insulating cylinder, and the shape shown in FIG. 3 (0) is rolled into a cylindrical shape. It becomes. The discharge electrode 1 is formed of a single heating wire stretched along the axis of this cylinder. This discharge electrode l is the switch mechanism 11 shown in FIG.
, 13 are connected to a high voltage power source and a heating power source, and the dust collecting electrode 2 is connected to conductive wires 4 . . . in the same manner as in FIG. 2.

[action, effect]

This invention has the above-mentioned configuration, and after the entire device is placed in a duct of a sample gas to be measured, a high-voltage direct current is applied between the discharge electrode 1, which is a cathode, and the dust collection electrode 2, which is an anode. After applying a voltage and applying a high-pressure electrostatic field to the sample gas to cause corona discharge, the gas near the cathode turns into a corona and the particles are negatively charged, causing the particles to adhere to the anode.
The concentration of adhered particles is measured by connecting the parallel conducting wires 4 of the dust collection electrode 2 to the power source 7 via the changeover switch mechanism 5.6, but in this case, if the amount of adhered particles exceeds a certain level, Since measurement becomes impossible, electric current is sent from the power source 8 to the conductors 4 to cause red-hot combustion and regeneration.

Calculation of particle concentration is based on the ratio of the change in current (Δt) per unit time (Δt) (ΔI/Δt), which is proportional to the amount of particles adhering between the electrodes. The concentration can be determined from the value.

The present invention has a simple configuration as described above, and can easily measure the concentration of contained particles, and can also be installed in the duct of a Cottrell dust collector and regenerate the dust collecting electrode of the Cottrell dust collector. It has the advantage that it can also be used as a sensor to indicate when the required time has arrived.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention. Fig. 1 is an overall perspective view, Fig. 2 is an explanatory diagram of the wiring of the dust collection electrode, and Fig. 3 (A) to (D).
) is a plan view showing each side of the arrangement shape of the conducting wires of the dust collection pole, FIGS. 4(A) to (D) are plan views showing the terminals connected to the conducting wires in FIG. 3 above, and FIG. 5 is the plan view shown in FIG. 1. FIG. 6 is an overall slope view showing another example, and is a principal slope portion showing a modification of FIG. 1. 1... Discharge electrode, 2... Dust collection electrode, 4... Conductive wire, 5
, 6... Changeover switch mechanism, 7... Power supply, 8, 14
...Heating power source, 9... Current judger, 10... Concentration calculator, 11.13... Changeover switch, 12... High voltage power source, a, b, c, d... Terminal, A...Ammeter. Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (2)

[Claims] (1) A dust collecting electrode consisting of a pair of parallel heating wires arranged in an appropriate shape along one surface, connected to a mechanism for applying high voltage DC voltage, and a metal wire at its discharge section. consists of a discharge electrode held so as to face approximately the center of the conductive wire arranged above, and a voltage is applied to the conductive wire forming the dust collecting electrode, a current is passed through it, and the amount of change in this current is measured. A device for measuring the concentration of particles in a sample gas, which is equipped with a mechanism that calculates the particle concentration by applying a current and a mechanism that burns and removes adhering particles by applying an electric current. (2) The conductive wire forming the discharge electrode is formed of a heating wire like the dust collecting electrode, and is equipped with a mechanism for burning off adhering particles by passing an electric current. Particle concentration measuring device.