JPH0476576B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method in which the detection section of a concentration meter is directly inserted into a flue or other duct, and a lead pipe connected to the detection section is inserted into the duct. The present invention relates to a simple soot and dust concentration meter that can measure the amount of soot and dust at a plurality of measurement points on the same line by adjusting the insertion length.

[Prior art and its problems] The concentration of so-called dust, such as soot and dust in exhaust gas generated from the use of fuel, synthesis, decomposition, and electricity, as well as dust generated from mechanical processing, etc. The method of measurement is specified in JIS Z8808.

This method is a filtration collection method using isokinetic suction, and is supposed to be expressed as the mass of dust contained in 1/m ³ N of dry exhaust gas.

However, this method is cumbersome in use, such as the need to measure the exhaust gas temperature, water content, static pressure, mass per unit volume, exhaust gas flow rate, etc., and to perform correction calculations.

On the other hand, soot and dust concentration meters used for continuous measurement in pollution prevention management and plant management such as collection ducts and chimneys are installed types in which the sample tube is fixed at the measurement point, and a part of the dust is placed outside the flue. A method is used in which the soot and dust concentration is measured by taking out a continuous stream into a measurement chamber and detecting this with a detector.

However, when measuring inside the flue, there are many target measurement points that must be measured intermittently.
In the conventional method, the measurement point is fixed at one point, so the sample tube must be replaced as the measurement point moves, and there are drawbacks such as measurement time and complexity of calculation, so this method saves labor. There was a demand for the development of a simple soot and dust concentration meter for this purpose.

[Specific means for solving the problem] Instead of the conventional fixed-point sampling method, the present invention directly measures the dust concentration in the duct by inserting the detection part into the duct. By adjusting the length of insertion into the duct, it is possible to measure the concentration of soot and dust at multiple measurement points on the same line. A light-emitting side unit is provided with an optical system at the tip of each lead pipe, and is disposed facing each other so that the light beam from each optical path port does not irradiate the opposing optical path port and intersects at an appropriate position. A detection section consisting of a light receiving side unit is attached, and each optical system is connected to the measurement section at the rear of the lead pipe via an optical fiber, and the lead pipe is
The detection section is characterized in that the length of insertion into a duct such as a flue is adjusted so that the detection section is placed at an appropriate measurement point within the duct.

[Example] Hereinafter, an example of the simple soot and dust concentration meter according to the present invention will be described with reference to the attached drawings.

The tip of the lead pipe 1, whose length is determined according to the diameter or cross-sectional length of the flue or duct to be measured, has a Y-shape that is symmetrical about the axis of the lead pipe 1. The base of the cylindrical body 2 is fixed by welding, and the outer surface of the lead pipe 1 is provided with a distance scale 3 from the center of the measuring section C, which will be described later.

Both ends of the Y-shape of body 2 have the same shape, the same size,
A light emitting unit A and a light receiving unit B having the same configuration are installed symmetrically.

Each of these units A and B includes stainless steel outer frames 4a and 4b in the shape of a cylindrical head with an open end inserted and fixed into the body 2, and a rectifying plate 5a and 5b, the outer frame 4a,
cylindrical ceramic inner frames 6a, 6b installed with a gap from 4b; collimators 8a, 8b with optical fibers 7a, 7b attached to the center of the inner frames 6a, 6b;
In the inner frames 6a, 6b ahead of the collimators 8a, 8b, horizontal holes 9a, 9b are bored in the diametrical direction passing through the centers of the inner frames 6a, 6b.
a rectangular prism 10 hermetically fitted to the outer wall of the
a, 10b, and quartz glass 11a, 11b hermetically fitted to the inner wall.

The ends of the optical fibers 7a and 7b are connected through the inside of the lead pipe 1 to a known measuring section (not shown) installed outside the lead pipe 1, and the optical fiber 7a on the light emitting side is connected to the light source of the measuring section. It is connected to the.

An appropriate number of ventilation holes 12a, 12b are bored on the circumference of the rectifying plates 5a, 5b, and a ventilation path 2 is formed between the inside of the lead pipe 1, the inner frames 6a, 6b, and the outer frames 4a, 4b.
0a, 20b are configured to be freely ventilable, and an appropriate number of air vents 13a, 13b are bored at the heads of the outer frames 4a, 4b on the circumference that coincides with the ventilation passages 20a, 20b. ing.

A flat portion 14 is provided in the axial direction on a portion of the opposing circumferences of both outer frames 4a and 4b.
a, 14b are formed, and these flat parts 14a, 14
An optical path opening 15 from the prisms 10a and 10b is installed at the end of the mounting body 2 at a position on b that corresponds to the mounting position of the quartz glasses 11a and 11b.
a, 15b are bored, and the plane parts 14a,
14b and the inner wall surface of each unit A, B attachment part in the body 2, and the gap that communicates with the inside of the lead pipe 1 is formed by the air curtain grooves 16a, 1.
6b.

The light emitting side unit A and the light receiving side unit B are arranged such that the light from the respective optical path openings 15a and 15b is on the center line of the lead pipe 1 and relative to the center line.
fixed to body 2 so as to intersect at an angle of 60°,
The intersection position of these lights is defined as the measurement position C.

At the tip of the body 2 on the center line of the lead pipe 1 between the light-emitting unit A and the light-receiving unit B, there is a scattering plate holder 18 with a standard scattering plate 17 located at the measurement position C. It is detachably attached to the hole 19.

When using the soot and dust densitometer configured in this way, the detection part body 2 must be inserted through the measurement hole provided in the duct (not shown) without the scattering plate holder 18 being attached to the attachment/detachment hole 19 of the body 2.
is specified based on the duct size (cross-sectional size) measured in advance so that the plane connecting the optical path of the light-emitting unit A and the light-receiving unit B is perpendicular to the flow of dust in the duct. Check the distance scale 3 on the lead pipe 1 to the measurement point and fix it.

In this way, light guided by the optical fiber 7a from the light source of the measuring section (not shown) passes through the collimator 8a of the light emitting unit A, is reflected at 90 degrees by the prism 10a, and is reflected by the quartz glass 10a.
1a, the dust is irradiated at the measurement part C in the duct through the optical path opening 15a, and the scattered light passes through the optical path opening 15b of the light receiving unit B, the quartz glass 11b, is reflected at 90 degrees by the prism 10b, and is transmitted to the optical fiber. 7b to the measuring section, and the soot and dust concentration in the duct is measured.

On the other hand, an air compressor (not shown) installed outside the duct sends air through the lead pipe 1 to the light emitting unit A and the light receiving unit B at a pressure higher than the pressure inside the duct.

This air flows through the ventilation holes 12a, 12b of the rectifying plates 5a, 5b of each unit A, B, the inner frames 6a, 6b and the outer frames 4a, 4b.
The air passes through the air passages 20a, 20b formed by the air passages 20a, 20b, and is blown out into the duct from the air blowholes 13a, 13b.

Also, some air does not pass through the rectifier plate,
The flow of air passing through the air curtain grooves 16a, 16b and blown out from the optical path openings 15a, 15b is pushed and bent to prevent disturbance of the optical axis in the optical path to the measuring section C.

After the measurement at a predetermined measurement point is completed, the lead pipe 1 is pulled out and pushed to the next measurement point while checking the distance scale 3 on the lead pipe 1 to reach another measurement point on the same line. By the way, this is fixed again, and the soot and dust concentration at that measurement point is measured according to the above-mentioned procedure.

In this way, by adjusting the insertion length of the lead pipe 1 into the duct, the soot and dust concentrations at a plurality of measurement points on the same line are measured.

The measurements are repeated and the quartz glasses 11a, 11
If the measured values are thought to be affected by dirt adhering to body 2 or cloudiness, etc., remove body 2 in a timely manner.
Attach the scattering plate holder 18 to which the standard scattering plate 17 is attached to the mounting/removal hole 19, measure the value of the scattered light of the standard scattering plate 17 in the same way as when measuring the dust concentration, and if there is a discrepancy with the standard value, Adjust the measured values in the measuring section.

[Effect] As described above, according to the simple dust concentration meter of the present invention, the dust is directly irradiated with light in the flue (inside the duct) and measured, so the detection part outside the flue is forcibly removed. Compared to the conventional measurement method, which involves sucking up soot and dust and irradiating it with light, this method does not require the time required for sampling, and it is possible to determine the concentration instantaneously in terms of time and space. It is possible to measure the soot and dust concentration at multiple measurement points along a straight line simply by adjusting the insertion length of the lead pipe, eliminating the need for multiple correction calculations for sampling air, and it is compact and lightweight. It is easy to handle, saves labor by not requiring manpower or time, and has excellent effects as a simple soot and dust concentration meter, such as being useful for combustion management, pollution prevention management, and even simplification of the JIS method.

Additionally, the temperature in ducts such as flues is generally high, and if a detection unit with an optical system is left in such high temperatures for a long time, the optical system may become distorted or the optical axis may shift. However, as shown in the example, the optical system is protected by an inner frame made of highly insulating ceramic, and a compressor is used from outside the duct to reduce the pressure inside the duct (inside the flue). By continuously feeding a certain amount of air set at a high temperature, the outer periphery of the inner frame is constantly cooled, which has the effect of keeping the inside of the optical system at a constant temperature, and the quartz glass placed in the optical path. It also has the effect of preventing the adhesion of dust and has a cleaning effect, and allows continuous measurement at high temperatures.

[Brief explanation of the drawing]

The drawings show an embodiment of the simple soot and dust concentration meter according to the present invention, in which FIG. 1 is a sectional view of the main part, FIG. 2 is a side view, and FIG. 3 is a plan view. 1...Lead pipe, 3...Distance scale, 4a,
4b... Outer frame, 6a, 6b... Inner frame, 7a, 7b... Optical fiber, 8
a, 8b... collimator, 10a, 10b...
Right angle prism, 11a, 11b... quartz glass,
15a, 15b... optical path opening, 16a, 16b...
Air curtain groove, 17...Standard scattering plate, 18...
...Scatter plate holder, A... Light emitting side unit, B...
...Light receiving side unit, C...Measurement section.

Claims (1)

[Claims] 1. Each of the long lead pipes is provided with an optical system at its tip, and the light beams from each optical path port are opposed to each other so that they do not irradiate the opposing optical path port and intersect at appropriate positions. A detection section consisting of a light emitting side unit and a light receiving side unit arranged at 1. A simple dust and dust concentration meter characterized in that the detection section is arranged at an appropriate measurement point within the duct by adjusting the length of insertion into the duct such as a road. 2. The light-emitting side unit and the light-receiving side unit are composed of an inner frame and an outer frame that support the optical system, and a ventilation passage communicating with the inside of the lead pipe and the outside of the outer frame is formed between the two frames, and the inner frame The simple dust concentration meter according to claim 1, wherein the light emitting side unit and the light receiving side unit are made of a material with low thermal conductivity such as ceramic. 3. The simple soot dust filter according to claim 1 or 2, wherein the light path opening in the light emitting side unit and the light receiving side unit is a light path opening provided at the end of an air curtain groove that communicates with the inside of the lead pipe. Densitometer. 4. The simple impurity concentration device according to any one of claims 1 to 3, wherein the lead pipe is a lead pipe with an appropriate number of lengths from the tip of the detection part indicated in the axial direction on its outer periphery. Total. 5. Claims 1 to 4, wherein the detecting section is a detecting section having a detachable scattering plate holder in which the scattering plate is positioned at the measuring section at the intersection of the optical paths of the light-emitting side unit and the light-receiving side unit. The simple dust concentration meter described.