JP3448157B2 - Probe tube for gas sampling - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is provided, for example, in a flue duct of flue gas discharged from a power generation boiler such as a coal-fired boiler or a heavy oil-fired boiler, and a part of this flue gas is used in a gas analyzer. The present invention relates to a sample gas sampling probe tube that is used to supply and analyze a gas component.

[0002]

2. Description of the Related Art As shown in the above-mentioned example, NO _x is contained in combustion exhaust gas discharged from a boiler that burns coal or heavy oil,
SO _X, contain components such as SO _2, CO _2, CO, and the component amount constantly analyzed by a gas analyzer, which help the analysis denitration, the control of the desulfurization.

In this case, the gas component analysis makes it possible to control the ideal exhaust gas component in a timely and appropriate manner if the gas component actually collected is immediately discriminated.
It can be expected to make a great contribution to industrial use.

One means for satisfying the above requirements is to enhance the high speed response of the gas analyzer.
Therefore, as shown in FIG. 12, the presently implemented probe tube 01 for collecting gas of this kind is inserted and arranged from the side surface of the flue 02 into the flue 02 in a posture orthogonal to the combustion exhaust gas flow 0V. Moreover, its diameter (inner diameter) 0D is 20
The suction port 03 at the lower end is located higher in the downstream side of the combustion exhaust gas flow 0V, and is formed so as not to directly face the combustion exhaust gas flow 0V. It is provided with a structure in which a large amount of combustion exhaust gas is sucked from 03.

[0005]

However, a large amount of dust and soot (hereinafter referred to as "dust") is mixed in the combustion exhaust gas from the boiler as described above, and this dust is inevitably contained during gas sampling. Although they are sucked together, it is more difficult than before to treat the sucked dust. Therefore, as the combustion exhaust gas is sucked in a larger amount in order to improve the high-speed response of the gas analyzer, the amount of sucked dust increases, and it is difficult to improve the high-speed response of the gas analyzer. Also, disposing this type of gas sampling probe tube at a sampling point with a large amount of dust is also problematic in view of the difficulty of dust processing, and various examinations are required for setting the installation location thereof. Since various dust removing means must be adopted, the apparatus is inevitably increased in size and the structure is complicated, and there is a problem in cost. Further, according to this conventional technique, the flow of the combustion exhaust gas acts directly on the suction port to increase the suction amount of dust.

The present invention was devised in view of the above-mentioned problems of the prior art. A first object of the present invention is to downsize the device,
While the structure can be simplified, the dust treatment can be significantly facilitated by a simple means, and at the same time, the gas analyzer can be remarkably fast-responsive, for example, when it is used for controlling denitration, desulfurization, etc. , It is to provide a gas sampling probe tube which can be expected to have high efficiency. A second object is to provide a probe tube capable of more efficiently treating dust while achieving the simplification of the structure of the probe tube in addition to achieving the first object. . A third object is, in addition to achieving the first object, to provide a probe tube capable of more efficiently performing dust treatment between the suction port and the main body of the probe tube. A fourth object is to provide a probe tube that can maintain strength enough to withstand the flow velocity in the gas flow path and can more efficiently perform dust treatment.

[0007]

In order to achieve the above object, the gas sampling probe tube of the present invention is provided in a gas flow path.
Inserted and aspirated for sample gas uptake at the tip
The mouth is open to the downstream side of the gas flow,
The diameter of this suction port is such that the suction flow rate at this suction port is
It is dimensioned to be 1/5 or less and
The lower wall of the inlet is equipped with an inclined surface that is lower on the downstream side of the gas flow.
The suction port is formed in a funnel shape.
To do. That is, as shown in the principle diagram of FIG. 1, the probe tube 1 for gas sampling has a shape structure in which the dust 5 does not reach the gas suction port 2 directly, and the dust 5 at the suction port 2 The structure is provided with a diameter d so as to reduce the suction flow rate vcm / sec as much as possible. Then, such a shape structure that the dust 5 does not directly reach the gas suction port 2, and a suction flow velocity vcm / sec of the dust 5 at the suction port 2
In combination with the diameter d for making the value as small as possible, the suction of dust is reduced as much as possible, the treatment is also simple, and the remarkably high-speed response of the gas analyzer can be achieved.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is, for example, inserted and arranged in a gas flow path such as a flue duct of combustion exhaust gas discharged from a power generation boiler, and a suction port 2 for taking in sample gas at the tip is gas. The flow velocity 4 is opened toward the downstream side of the flow 4, and the suction flow velocity vcm / sec of the suction port 2 is equal to the gas flow velocity V.
The diameter d of the suction port 2 is set so as to be 1/5 or less of cm / sec, and the lower wall 3 of the suction port 2 is provided with an inclined surface which becomes lower toward the downstream side of the gas flow 4. There is something.

The reason why the diameter d of the suction port 2 is set so that the suction flow velocity vcm / sec of the suction port 2 is not more than one fifth of the gas flow velocity Vcm / sec is as follows. Figure 11
Is a gas sampling probe tube according to the present invention having the structure shown in FIG. 1 and a gas sampling probe tube according to the prior art shown in FIG. 12, with a dust concentration of 30 g / Nm ³
It shows the relationship between the sampled gas velocity ratio and the measurement result of the sampled gas concentration when installed in the flue where the coal combustion exhaust gas flows. The probe tube 1 according to the present invention has an inner diameter Dφ.
The diameter dφ of the suction port 2 is changed at (8 mm), and the ratio of the opening area between the probe tube and the suction port 2, that is, d /
The measurement result when D is 1.0, 3.5, and 7.0 is shown.

As can be understood from the measurement results, it is understood that the area ratio between the suction port 2 and the probe tube 1 becomes the flow velocity ratio near the suction port, which greatly affects the concentration in the sampled gas. Therefore, in the structure shown in FIG. 1 according to the present invention, if the dust removal rate is set to 95% or more, the sample dust concentration of 1.5 g / Nm ³ in FIG. The area ratio (d / D) ² of the suction port 2 is about 5 times.

By the way, on the extension line of the measurement example shown in FIG. 11, when the dust removal rate of the probe tube (tip 45 ° cut) according to the conventional technique shown in FIG. 12 is observed, it is 84%.
It was about.

If the sampled gas flow rate ratio is ⅕ or more, the amount of suctioned dust increases, and it is difficult to dispose it at a sampling point with a large amount of dust, making it difficult to improve the high-speed response of the gas analyzer. Therefore, the problems caused by the conventional technology will appear remarkably. On the contrary, a remarkable effect can be seen even when the area ratio (d / D) ² of the suction port 2 to the probe tube 1 is about 50 times. In other words, the initial dust removal effect can be obtained even if the sampling gas flow rate ratio is set to 1/50 or less. Due to the structure, the setting of the flow velocity ratio is
Although it is determined by the area ratio (d / D) ² of the suction port, it corresponds to the length h and the diameter dφ in the funnel-shaped suction portion 2A of FIG. Specifically, when measuring the flue gas, it is necessary to manufacture the flue gas with a size equal to or smaller than the pipe diameter of the sampling point flange installed in advance. Therefore, the size that satisfies the above area ratio (d / D) ² is limited by the inner diameter of the flange.

While the apparatus can be downsized and the structure can be remarkably simplified, the dust treatment can be remarkably easily performed by a simple means, and at the same time, the remarkably high-speed response of the gas analyzer can be achieved, and the dust can be treated. In order to achieve the second object of providing a probe tube capable of more efficient processing, the probe tube has a main body formed in a hook shape and a funnel shape formed at the tip thereof. It is even more effective to adopt a configuration having a suction port.

A portion of the main body of the probe tube is inserted and arranged in the gas flow passage so that the angle of the suction port with respect to the gas flow is adjusted according to the amount of dust in the gas flow passage.
A flexible structure can also be provided.

Further, in order to achieve the third object of more efficiently performing the dust treatment from the suction port to the main body of the probe tube, the tip of the main body of the probe tube is formed in a zigzag suction flow path. A suction port for taking in sample gas is opened at the tip of this suction flow path toward the downstream side of the gas flow, and the diameter of this suction port is such that the suction flow velocity at this suction port is at least 5 minutes of the gas flow velocity. It is possible to adopt a configuration in which the lower wall which is connected to the suction port of the zigzag suction flow path is formed to be an inclined surface which becomes lower toward the downstream side of the gas flow.

[0016] The strength which can sufficiently withstand the flow velocity in the gas flow passage can be maintained, and at the same time, the dust treatment can be performed more efficiently.
In order to achieve the above-mentioned object, it is possible to adopt a configuration in which the probe tube is entirely surrounded by a reinforcing structure in a posture in which the suction port 2 for taking in the sample gas is opened to the downstream side of the gas flow 4.

[0017]

When the sample gas is sucked from the suction port 2 to collect the sample gas by the gas sampling probe tube configured as described above, as shown in the principle diagram of FIG.
The sample gas intake suction port 2 that is opened toward the downstream side of the gas flow 4 has a positive effect that the gas flow positively removes dust, like a conventional suction port that is simply opened in a direction orthogonal to the gas flow. Unlike the structure in which the gas 5 is pushed into the suction port, the dust 5 mixed in the gas flow 4 is once made to flow to the downstream side of the suction port 2 and then placed on the suction flow 6 from the suction port 2. , The structure is such that it makes a U-turn in a direction completely opposite to the direction of the gas flow 4 up to now, and the dust 5 cannot be easily sucked, and by causing this U-turn phenomenon, it is relatively heavy and large. The dust 5 is allowed to flow down to the downstream side without being sucked by the inertia I, does not easily reach the suction port 2, and only the lightweight and minute dust 5a that can float in the suction flow 6 rides on the suction flow 6. Work for
Here, the function of classifying and separating the dust works.

The classifying / separating action is promoted by the lower wall 3 of the suction port 2 having an inclined surface which becomes lower on the downstream side of the gas flow 4. That is, the inclined lower wall 3 does not cause the gas flow 4 to linearly flow from the upstream side to the downstream side, but positively guides the gas flow 4 to the side away from the suction port 2 toward the downstream side on the outer surface of the inclined surface. Thus, it acts so as to positively give the inertia I in the direction further away from the suction port 2 so that the dust cannot easily get on the suction flow 6.

Moreover, the suction flow velocity vcm is set by the suction port 2 whose size is set to be one fifth or less of the gas flow velocity.
/ Sec is made as small as possible, and the light and minute dust 5a that gets into the suction port 2 by riding on the suction flow 6 is also settled in the suction port 2 due to its own weight. It works so that it is deposited on the lower wall 3 of this suction port 2 having an inclined surface that becomes lower on the downstream side of the probe tube. Even though it is lightweight and minute dust 5a, it is easily sucked up to the main body 1A of the probe tube. Work not to. And the lower wall 3 of this suction port 2
To fall on, when deposited to a certain thickness, and Tsu by its own weight or the like of the vibration or the deposition of dust probe tube 1, the slope of the lower wall 3 acts so as to fall the deposition dust naturally.

As shown in FIG. 3, the main body of the probe tube is formed in a hook shape, and the funnel-shaped suction port is provided at the tip of the main body of the probe tube as shown in the above-mentioned principle diagram. While working well, it also works to simplify the structure of the probe tube itself, especially without letting the gas flow linearly flow from upstream to downstream,
The so-called trumpet-shaped outer surface is positively guided toward the side that is radially away from the entire circumference of the suction port as it goes downstream, and is further away from the suction port 2 so that the dust cannot easily get on the suction flow. It works to give inertia in the direction.

As shown in FIG. 4, the tip of the main body of the probe tube is formed in a zigzag suction flow path, and a suction port for taking in sample gas is directed to the downstream side of the gas flow at the tip of this suction flow path. And the diameter of this suction port is set so that the suction flow rate at this suction port is not more than one fifth of the gas flow rate, and the suction port of this zigzag suction flow path is The configuration in which the lower wall that is connected to the lower surface is formed on the inclined surface that becomes lower on the downstream side of the gas flow is that the dust that has reached the zigzag suction flow path is also displayed while successfully exerting the action as shown in the above principle diagram. , At the curved part of the flow path, that is, at the turning point, it works by making good use of the inertial force in the straight direction up to now and hitting the wall of the curved part of the flow path to make it fall from the suction flow. Repeated several times, suction flow of dust Working free al so much enhanced.

Further, as shown in FIGS. 5 to 8, the structure in which the entire probe tube is surrounded by the reinforcing structure in a posture in which the suction port for taking in the sample gas is opened to the downstream side of the gas flow The suction port 2 shown in the principle diagram of FIG. 1 is used while also exerting the effect as shown in the principle diagram, and at the same time, acts to maintain strength enough to withstand the flow velocity in the gas flow path. In the same way that the lower wall 3 acts on the gas flow 4, the gas flow 4 does not flow straight down from upstream to downstream, and the side away from the suction port on the outer surface of the reinforcing structure toward the downstream side. Positively guiding the dust to the inertial flow in a direction away from the suction port so that the dust cannot easily get on the suction flow.

Further, as shown in FIG. 9 and FIG. 10, at the portion inserted and arranged in the gas flow path of the main body of the probe tube,
The structure with a flexible structure is able to perform the function as shown in the above principle diagram well, and at the same time, the angle of the suction port with respect to the gas flow direction can be freely changed and adjusted according to the amount of dust in the gas flow path. And work to get the most ideal angle.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A case where the present invention is applied to an exhaust gas passage of combustion exhaust gas discharged from a boiler for burning coal will be described below with reference to the drawings. FIG. 2 shows the overall configuration of a gas sampling apparatus to which the present invention is applied, and shows a gas sampling probe tube 11 provided in the flue 10.
The sampling gas collected in 1 is sent to the gas analyzer A through the sample gas supply path R. Then, in the sample gas supply path R from the gas sampling probe tube 11 to the gas analyzer, a cyclone S for separating dust, a sampling pump P and a pair of filters F sandwiching the front and rear thereof. Further, a dehumidifying device E and a sluice valve V are appropriately provided. The gas analyzer A includes a gas analyzer (not shown), a CPU for controlling and processing data,
It is equipped with a display unit and the like, and is configured so that one or more of the components such as SO ₂ , NO _X , CO ₂ and CO in the supplied sample gas can be analyzed continuously and at high speed. .

Therefore, FIG. 3 schematically shows a gas sampling probe tube according to the first embodiment of the present invention. In FIG. 3, 10 is a flue, through which combustion exhaust gas flows. Reference numeral 11 denotes a probe tube which is inserted and arranged in the flue 10 and serves as a gas sampling section. The probe tube 11 collects a part of the combustion exhaust gas as a sample gas. Then, the sample gas collected by the probe tube 11 is supplied from the main body 11A of the probe tube 11 to the gas analyzer A via the sample gas supply path R as shown in FIG.

As shown in FIG. 3, the probe tube 11 has a tip 11 B in which the tip 11 B is located inside the flue 10.
It is bent into an L-shape so as to be opened toward the downstream side in the gas flow direction 14 of the combustion exhaust gas. The tip 11B is provided with a wall that widens in the radial direction toward the downstream side in the gas flow 14 direction, and is, so to speak, a funnel-shaped suction port 12
Are installed in a row. The opening angle θ of the funnel-shaped suction port 12 is about 30 ° to 100 ° depending on the condition of the flue.
Is appropriately selected within the range of, but is preferably set to about 90 °.

The present invention is characterized by the fact that the suction port 12 is formed in a funnel shape as described above, and the opening diameter is set within a certain range. Both characteristics work synergistically, and the suction of the dust 15 can be reduced as much as possible. Therefore, this suction port 1
The diameter d of 2, that is, the inner diameter of the funnel-shaped open edge is 40 to
It is formed to 50 mm. This value is obtained as a result of various experiments by the inventors of the present invention over many years and basically follows the basic law that the amount of dust 15 taken in is inversely proportional to the opening diameter of the tip of the probe tube. Is configured.

Specifically, the suction flow velocity vcm / sec at the suction port 12 is set so as to be one fifth or less of the gas flow velocity Vcm / sec of the combustion exhaust gas. In consideration of this condition and the condition that the flow velocity for suction applied to the probe tube 11 is generally 50 to 200 cm / sec, in the present embodiment, this probe tube 1 is used.
The inner diameter D of the main body 11A of FIG.
The diameter is set to 8 to 10 mm, which is about one fifth of the diameter d. Therefore, as compared with the conventional structure shown in FIG. 11, a diameter reduction of about 30 to 40% can be achieved.

When the sample gas is sucked from the gas sampling probe tube 11 thus constructed, the probe tube 11
Since the diameter d of the suction port 12 is larger than the inner diameter D of the suction port 12 by about 5 times as described above, the suction flow velocity at the suction port 12 portion is significantly slowed down, and the dust 15 that is about to be sucked together with the sample gas Does not ride on the suction flow 16 due to its own weight and settles on the inclined lower wall 13 of the suction port 12, that is, the inner surface of the funnel, and is not easily sucked by the probe tube 11.

Further, since the suction port 12 is open toward the downstream side in the direction of the gas flow 14 of the combustion exhaust gas, a large amount of dust 15 is flown to the downstream side of the suction port 12 due to the inertia I, which is easy. In addition, the suction flow 16 does not reach the suction port 12, and only the lightweight and minute dust 15a that can float in the suction flow 16 remains.

Further, since the suction port 12 is formed in a funnel shape, the combustion exhaust gas is guided to the inclined outer surface thereof and does not flow straight down from the upstream side to the downstream side. The inertia I in the direction further away from the suction port 12 is positively guided so that the dust 15 cannot easily get on the suction flow 16 as being guided toward the side further away from the suction port 12 as it goes toward the downstream side. The amount of dust taken in can be further reduced.

Moreover, the suction flow 16 reaches the inside of the suction port 12, where it settles on the inner surface of the funnel, and the light and minute dusts 15a are successively deposited on the inner surface of the funnel. Due to the vibration of the probe tube 11 or the self-weight of the accumulated dust, the probe tube 11 is naturally guided by the inclination of the funnel and falls into the flue, and is discharged to the downstream side by the combustion exhaust gas.

As described above, in the gas sampling probe tube according to the present invention, in addition to the feature that the suction port 12 is formed in a funnel shape as described above, the opening diameter thereof is within a certain range. The stipulations act synergistically, and while the device can be downsized and the structure can be simplified, the dust treatment can be significantly facilitated by a simple means, and at the same time, the gas analyzer can be remarkably fast-responsive. When used for controlling denitration, desulfurization, etc., high efficiency can be expected.

Next, the structure shown in FIG. 4 shows a second embodiment, and roughly speaking, the main body 11A of the probe tube.
11B is formed in a zigzag suction flow path, and a suction port 12 is opened at the tip of this suction flow path toward the downstream side of the gas flow 14, and the diameter d of this suction port 12 is 12 shows an example in which the suction flow velocity vcm / sec of 12 is set to be equal to or less than one fifth of the gas flow velocity Vcm / sec of the combustion exhaust gas.

The specific structure of the zig-zig-shaped suction flow path is as follows. As shown in the drawing, the main body 11A of the probe tube 11 is a straight tube and is inserted and disposed in the flue gas 10 of the combustion exhaust gas in a substantially vertical posture.
The primary expanded passage 11a is connected to the lower end of the. A suction passage 11b, which opens the tip toward the downstream side of the gas flow 14 and serves as a suction port 12, is connected under the primary expanded passage 11a. The primary expanded passage 11a is composed of a case 17 having a rectangular cross-sectional shape along the gas flow 14 direction, and one diagonal line of the case 17 is arranged along the vertical direction. The upper corners, which are opposed to each other on the diagonal line, are connected to the lower end of the main body 11A through the communication port 11
and the suction path 11 is provided at the other corner.
A communication port 11d that is continuous with the upper end of b is opened.

The suction passage 11b is connected to the gas flow 14
Case 18 with a rectangular cross-section along the direction
And a lower wall 17a of the case 17 forming the primary expanded passage 11a has an upper end corner portion formed with the communication port 11d.
Through the primary expanded passage 11a, and the lower end is continuously arranged in an inclined posture in which the lower end is positioned lower toward the downstream side in the gas flow 14 direction. The lower end of the inclined case 18 is connected to the suction port. There are twelve.

By combining the rectangular case 17 and the rectangular case 18 as described above, the tip 11B of the main body 11A is formed into a zigzag-shaped suction flow path, and the flow path from the suction port 12 to the main body 11A is formed. Is meandered, so that the suction of the dust 15 is reduced as much as possible. Further, the lower wall 13 that is connected to the suction port 12 of the inclined case 18 has an inclined posture that is positioned lower toward the downstream side in the gas flow 14 direction.

The suction port 12 opened at the lower end of the case 18 is formed by cutting the lower end of the case 18 in an inclined posture along an imaginary vertical line as shown in the drawing. Suction flow rate of this suction port 12 vcm /
The diameter d is set so that sec is not more than 1/5 of the gas flow velocity Vcm / sec of the combustion exhaust gas.

Therefore, the light and minute dust 15a which is about to be sucked from the suction port 12 goes straight by the inertia I ₀ and first hits the upper end wall of the case 18 in the inclined posture, where it is once classified and separated. To be done. Then, the dust 15a that has fallen adheres and accumulates on the inclined lower wall 13 of the case 18, but when it accumulates to a certain thickness,
Due to the vibration of the probe tube 11 or the self-weight of the accumulated dust, the probe tube 11 is naturally guided by the inclination of the lower wall 13 and falls into the flue 10, and is discharged downstream by the combustion exhaust gas.

Further, the lighter and finer dust 15a is sucked into the primary expanded passage 11a through the communication port 11d at the upper end corner, but the primary expanded passage 11a is constructed in a large room. As a result, the suction flow inevitably has a slow velocity, so that the dust 15a undergoes further classification / separation, and most of it falls and settles. Here, the dust 15a that has fallen is present on the downstream side of the gas flow 14 of the rectangular case 17, and the inclined wall 17a.
Although it adheres to and deposits on the upper surface, when it is deposited to a certain thickness, it is naturally guided by the inclination of the lower wall 17a by the vibration of the probe tube 11 or the self-weight of the accumulated dust, and the like through the communication port 11d. It falls into the inclined case 18, falls into the flue 10 in the same manner as described above, and flows down to the downstream side by the combustion exhaust gas.

In this way, the probe tube 1 is drawn from the suction port 12.
By making the suction flow path meandering several times to reach the main body 11A of No. 1, it was possible to effectively utilize the inertial force and enable effective dust separation.

As shown in the figure, the primary expansion path 1
The inclined wall 17a on the downstream side of the gas flow 14 of the rectangular case 17 forming 1a is extended into the inclined case 18, and the narrow portion 18A is provided in the flow path in the inclined case 18.
If this is formed, the suction flow downstream side of the narrow portion 18A can be formed as an expansion path, and the dust classification / separation action can be more effectively exhibited in combination with the primary expanded path 11a.

Next, the configuration shown in FIG. 5 and FIG.
A third embodiment is shown and, to put it roughly, the probe tube 1
1 shows a structure surrounded by a reinforcing structure 19 in a posture in which a suction port 12 for taking in a sample gas is opened to the downstream side of a gas flow 14, and this reinforcing structure 19
Is composed of an outer tube 20 and a tip flow path forming body 21 integrally connected to the lower end thereof.

Specifically, the main body 11A of the probe tube 11 is a straight tube, and although not shown, it is inserted and disposed in the flue 10 of the combustion exhaust gas in a substantially vertical posture. The outer side of 11A is surrounded by another straight tubular outer tube 20. The outer tube 20 is made of, for example, a pipe made of stainless steel, and has a slightly larger diameter so that a predetermined space is formed on the outer periphery of the main body 11A as shown in the figure. ing.

The tip flow path forming body 21 is formed of a heat resistant material such as ceramic or quartz glass, and is formed in a cylindrical shape having a diameter equal to that of the outer tube 20. They are integrally connected to the lower ends of the straight-tube main body 11A and the outer tube 20. Then, as shown in the figure, the columnar tip flow path forming body 21 is provided with a suction port 12 in an attitude of being opened to the downstream side of the gas flow 14, and the suction port 12 and the main body 11A. Tip 11 of
An L-shaped flow path 22 that communicates with B is formed.

In the reinforcing structure 19, the probe tube 11 is sucked into the sample gas suction port 12 as described above.
Surround the whole in a posture in which it is opened to the downstream side of the gas flow 14, so that as shown in FIG. 6, the combustion exhaust gas is exposed to the upstream side of the gas flow 14 of this cylindrical reinforcing structure 19. It is guided by the half-circle that runs down to the downstream side. At this time, the dust 15 has a tendency to linearly flow down to the downstream side without wrapping around to the suction port 12 side due to the inertia I when passing through the maximum diameter portion of the reinforcing structure 19, so that At this point, primary classification of heavy and large dust
Allows separation. In this embodiment, the presence of the reinforcing structure 19 enables the flow of the combustion exhaust gas to be greatly separated from the suction port 12, and has a dust classification / separation action as compared with the structure shown in FIG. It can be remarkably effective, the amount of dust suction can be reduced as much as possible, and the high-speed response of the gas analyzer can be remarkably improved. Further, it is inevitable that the strength of the flue 10 that can withstand the gas flow velocity in the flue 10 can be maintained, so that it is suitable for a flue having a high pressure and high speed flow.

Further, in this reinforcing structure 19, the main body 11A of the probe tube shown in FIG. 3 is formed in a hook shape, and the suction port 1 formed in a funnel shape at the tip thereof.
2, the tip portion 11B of the main body 11A of the probe tube is formed in a zigzag-shaped suction flow path, and the suction port 12 formed in a funnel shape is provided at the tip thereof. It can also be applied to structures that have
As shown in the fourth embodiment of FIG. 7 and the fifth embodiment of FIG. 8, the probe tube 11 is surrounded only by the outer tube 23 which is made of stainless steel and whose lower end is closed. Therefore, in this example, the tip channel forming body 21 shown in FIGS. 5 and 6 is not required, and a probe tube having a simple structure can be obtained.

The structure shown in FIG. 9 shows the sixth embodiment of the present invention, and the structure shown in FIG. 10 shows the seventh embodiment of the present invention, both of which are shown in FIG. A portion located in the flue (see FIGS. 1 and 3) near the tip 11B, to which the suction port 12 is integrally connected, is configured by a flexible structure 24, as shown in the principle diagram of FIG. While demonstrating the action well, the angle of the suction port 12 with respect to the gas flow direction can be freely changed and adjusted according to the amount of dust in the gas flow path to obtain the most ideal angle. When placing the probe tube in the flue,
The flexible structure 24 is straightened and inserted into the flue, and then the flexible structure 2
The suction port 12 can be adjusted to a predetermined proper angle via the connector 4, and the device is devised so that the installation hole formed in the flue is as small as possible.

Therefore, the flexible structure 24 shown in FIG. 9 specifically illustrates a case where the flexible metal tube 24A is adopted. Also, the flexible structure 24 of FIG.
Shows a modification of the structure shown in FIG. 9, and is a flexible tube 2 made of a heat-resistant synthetic resin such as Teflon.
The outer periphery of 4B is surrounded by a plurality of protective tubes 24C. Specifically, the short pipe 24a formed to have a larger diameter toward the suction port side, the small diameter side of the next short pipe 24a is sequentially inserted into the large diameter side, and the fitting portions are connected to each other by the pin 24b. The protective tube 24C surrounds the outer circumference of the flexible tube 24B, the suction port 12 is provided at the tip of the flexible tube 24B, and the probe tube is provided on the opposite side. Body tip 11
They are connected to B respectively.

[0050]

As described above, in the gas sampling probe tube according to the present invention, unlike the conventional method, the suction port for taking in the sample gas is opened toward the downstream side of the gas flow. The dust mixed in the gas flow once flows to the downstream side of the suction port, then rides on the suction flow from this suction port and makes a U-turn in the direction completely opposite to the gas flow direction up to now. Therefore, it is necessary to allow relatively heavy and large dust to flow down to the downstream side as it is without being sucked due to inertia so that only light and minute dust that can float in the suction flow remains. In addition, the dust classification / separation function works well, the amount of suction dust can be significantly reduced, and the gas analyzer can have a significantly high-speed response.For example, it can be used for controlling denitration and desulfurization. When, the efficiency can be expected.

The diameter of the suction port is dimensioned so that the suction flow velocity at the suction port is not more than one fifth of the gas flow velocity, so that the suction flow velocity at the suction port is vcm / se.
Light weight and minute dust that gets into the suction port by riding on the suction flow can be well settled by its own weight inside the suction port, further reducing the suction amount of dust. As a result, the gas analyzer can have a higher response speed.

Further, since the suction port is provided with a slanted lower wall which becomes lower on the downstream side of the gas flow, it is possible to reduce the weight and weight of the thin wall that has fallen on the lower wall and accumulated to a certain thickness.
Small dust can be naturally dropped by the inclination of this lower wall due to the vibration of the probe tube or the self-weight of accumulated dust, etc. It is possible to achieve high-speed response.

As described above, in the present invention, since the suction amount of dust can be reduced as much as possible, it is necessary to remove dust disposed in the sample gas supply path from the probe tube to the gas analyzer. The various devices and parts can be replaced with a simple structure, and in some cases, these devices and parts can be omitted, so that the structure of the entire device can be simplified and can be economically provided.

Further, according to the present invention, by adopting a structure in which the main body of the probe tube is formed in a hook shape and the suction port formed in a funnel shape is provided at the tip thereof, the gas as described above is obtained. The high-speed response of the analyzer can be achieved, and the overall structure of the probe tube can be significantly simplified. In particular, the gas flow is not allowed to flow straight down from the upstream side to the downstream side, and so to speak, the trumpet-shaped outer surface positively guides it toward the side away from the entire suction port radial direction toward the downstream side, Since it is possible to positively give inertia in a direction further away from the suction port such that the dust cannot easily get on the suction flow, the suction amount of dust can be significantly reduced, and the high-speed response of the gas analyzer can be improved. Further improvement can be achieved.

In addition, by providing a flexible structure at the portion of the main body of the probe tube that is inserted and arranged in the gas flow path, the gas as shown in the principle diagram of FIG. Depending on the amount of dust in the flow path, the angle of the suction port with respect to the gas flow direction can be freely changed and adjusted to obtain the most ideal angle, further improving the high-speed response of the gas analyzer. Moreover, even when the probe tube is placed in the flue, the flexible structure is straightened and inserted into the flue, and then the suction port is inserted through the flexible structure to a predetermined proper position. Since it can be adjusted to an angle, the installation hole for the flue can be made as small as possible, and the installation work can be simplified.

Further, by forming the tip of the main body of the probe tube into a zigzag-shaped suction flow passage, the high-speed response of the gas analyzer as described above can be achieved, and the zigzag suction flow passage can be obtained. At the curved part of the flow path, that is, at the turning point, it is possible to make good use of the inertial force in the straight ahead direction to hit the dust on the wall of the curved part of the flow path and drop it from the suction flow well. , By repeating this several times, the release of dust from the suction flow can be significantly increased, so the amount of dust suction can be significantly reduced, and the high-speed response of the gas analyzer can be further improved. it can.

Further, by enclosing the entire probe tube with the reinforcing structure in a posture in which the suction port for taking in the sample gas is opened on the downstream side of the gas flow, the high-speed response of the gas analyzer as described above. In addition to being able to maintain sufficient strength to withstand the flow velocity in the gas flow path, the gas flow is not allowed to flow linearly from upstream to downstream, and the external surface of this reinforcing structure Actively guiding the side away from the suction port as it goes downstream, so that the dust cannot easily get on the suction flow, it is possible to positively give inertia in a direction further away from the suction port, The amount of dust suction can be significantly reduced, and the high-speed response of the gas analyzer can be further improved.

[Brief description of drawings]

FIG. 1 is an explanatory view of the principle of a gas sampling probe tube according to the present invention.

FIG. 2 is a schematic explanatory view of an apparatus to which the gas sampling probe tube according to the present invention is applied.

FIG. 3 is a schematic cross-sectional view of a main part showing a first embodiment of a gas sampling probe tube according to the present invention.

FIG. 4 is a schematic cross-sectional view of an essential part showing a second embodiment of the gas sampling probe tube according to the present invention.

FIG. 5 is a schematic cross-sectional view of an essential part showing a third embodiment of the gas sampling probe tube according to the present invention.

6 is a cross-sectional view taken along the line AA in FIG. 5, showing a third embodiment of the gas sampling probe tube according to the present invention.

FIG. 7 is a schematic sectional view of an essential part showing a fourth embodiment of the gas sampling probe tube according to the present invention.

FIG. 8 is a schematic cross-sectional view of an essential part showing a fifth embodiment of the gas sampling probe tube according to the present invention.

FIG. 9 is a schematic sectional view of an essential part showing a sixth embodiment of the gas sampling probe tube according to the present invention.

FIG. 10 is a schematic sectional view of an essential part showing a seventh embodiment of the gas sampling probe tube according to the present invention.

FIG. 11 is a graph showing the characteristics of the sample gas flow velocity ratio and the sample gas dust concentration of the gas sample probe tube according to the present invention.

FIG. 12 is a schematic explanatory diagram of a conventional structure.

[Explanation of symbols]

1, 11 ... Probe tube, 1A, 11A ... Probe tube body, 1B, 11B ... Probe tube tip, 2, 12 ... Suction port, 2A ... Funnel-shaped suction section, 3, 13 ... Suction port lower wall,
4, 14 ... Gas flow, 5, 15 ... Dust, 5a, 15a
... Lightweight / fine dust, 6, 16 ... Suction flow, 10 ... Flue, 19 ... Reinforcement structure, 23 ... Outer tube, 24 ... Flexible structure, D ... Inner diameter of probe tube body, d ... Suction port diameter , G ... Combustion exhaust gas, h ... Length of funnel suction part, V ... Gas flow rate, v ... Suction flow.

Front page continued (72) Inventor Shigeyuki Akiyama 2 Higashimachi, Kichijoin Miya, Minami-ku, Kyoto, Japan Horiba Manufacturing Co., Ltd. (72) Inventor Masahiko Fujiwara 2 Higashi-cho, Kichijoin Miya, Minami-ku, Kyoto, Kyoto Inside the Horiba Plant (72) Inventor Satoshi Inoue 2 Higashimachi, Kichijoin Miya, Minami-ku, Kyoto City, Kyoto Prefecture (56) Inside the HORIBA MFG. Co., Ltd. (56) Reference JP-A-59-50336 (JP, A) JP-A-63-191943 ( JP, A) JP 1-232231 (JP, A) JP 2-115742 (JP, A) Actual opening 5-50341 (JP, U) Actual opening Sho 59-25453 (JP, U) Actual opening Flat 7-12952 (JP, U) Actual Open 56-105830 (JP, U) Actual Open 58-180451 (JP, U) Actual Open 59-120452 (JP, U) Actual Flat 2-79443 (JP , U) Sekikai Sho 60-173052 (JP, U) JPK Sho 53-28234 (JP, B2) JPK Sho 57-1778 (JP, B2) JPK Sho 62-45156 (JP, Y2) JPK Sho 50-29975 (JP, 2) the actual public Akira 58-24185 (JP, Y2) (58 ) investigated the field (Int.Cl. ^7, DB name) G01N 1/00 - 1/44 JICST file (JOIS)

Claims (5)

(57) [Claims] 1. A suction port for inserting a sample gas at the tip is opened toward the downstream side of the gas flow, and the diameter of this suction port is equal to that of the suction port. Is sized so that the suction flow velocity is less than one fifth of the gas flow velocity, and the lower wall of the suction port is provided with an inclined surface that becomes lower toward the downstream side of the gas flow, and the suction port is shaped like a funnel.
A gas sampling probe tube characterized by being formed. 2. The probe tube for gas sampling according to claim 1, wherein the main body of the probe tube is formed in a hook shape, and the suction port is provided at the tip thereof. 3. The gas sampling probe tube according to claim 1, wherein a portion of the main body of the probe tube that is inserted and arranged in the gas flow path has a flexible structure. 4. The tip of the main body of the probe tube is formed in a zigzag-shaped suction channel, and a suction port for taking in sample gas is opened at the tip of this suction channel toward the downstream side of the gas flow. The diameter of the suction port is set so that the suction flow velocity at the suction port is at least 1/5 or less of the gas flow velocity, and the lower wall of the zigzag suction flow passage that is continuous with the suction port is A gas sampling probe tube, characterized in that the gas sampling probe tube is formed on an inclined surface that becomes lower on the downstream side of the gas flow. 5. The probe tube according to claim 1, wherein the probe tube is in a posture in which a suction port for taking in the sample gas is opened to the downstream side of the gas flow, and is entirely surrounded by a reinforcing structure. The gas collection probe tube described.