JPS6338610B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a stack crane prevention device that is attached to the upper end of a chimney to prevent the occurrence of stack cranes.

In a static crane, the moisture in the flue gas rising inside the chimney condenses into water droplets on the way up, and these water droplets rise with the flue gas due to the overflow phenomenon caused by the rising action of the flue gas and scatter in all directions from the chimney.
It is a phenomenon that falls like rain around the chimney.

Conventionally, the device shown in FIG. 1 has been developed as a device for preventing the stack crane.

This device collides the exhaust gas rising inside the chimney with a porous moisture-absorbing material, thereby causing the moisture-absorbing material to capture water droplets that have risen together with the exhaust gas. 2, a porous hygroscopic material 3 attached to the inner periphery of the cylindrical body 2, a drift plate 4 for converting the flow of exhaust gas into a swirling flow in order to cause the exhaust gas to collide with the hygroscopic material 3, and the hygroscopic material 3. The structure includes a gutter 5 that collects water droplets trapped in the gutter 5, and a discharge device 6 that discharges the water droplets collected in the gutter 5 to the outside of the chimney 1.

By the way, chimneys that require such a device usually range from 50 to 200 meters in height and even several meters in diameter. On the other hand, in order to completely remove the water droplets that rise with the exhaust gas, the conventional device as mentioned above requires a height dimension of about 6 times the diameter of the chimney, and if the diameter of the chimney is 6 meters, If so, the height H (see Figure 1) of the device would be as high as 36 meters. In other words, the construction of the above-mentioned depot was a large-scale construction work at a high place, which caused problems such as a long construction period and a very high construction cost.

This invention has been proposed in view of the above circumstances, and has a new configuration for the means for capturing water droplets rising with exhaust gas, thereby reducing the height of the device to less than half that of the conventional device. is possible,
The object of the present invention is to obtain a stack crane prevention device that can shorten the construction period and reduce the construction cost by reducing the construction scale due to this compactness.

Embodiments of the present invention will be described below based on the drawings.

FIG. 2 is a side sectional view of an embodiment of the present invention,
10 is an existing chimney, and 11 is a stack crane prevention device according to the present invention.

The stack crane prevention device 11 is installed in the chimney 10.
It has a large diameter part 12a with a larger diameter, and the chimney 1
a cylinder 12 that is attached to the upper end of the cylinder 12 and serves as a passage for exhaust gas; and an external cylinder 14 that concentrically covers the outer periphery of the cylinder 12 and forms a space 13 that opens upward between the cylinder 12 and the cylinder 12. The inside of the cylinder 12 is vertically partitioned at a position corresponding to the large diameter part 12a, and at least one side is formed in the circumferential wall of the cylinder 12, and the exhaust gas is diverted from the opening 12b to the cavity 13.
It includes a plurality of water bottle collection plates 15 protruding inward.

The above-mentioned cylinder body 12 and external cylinder body 14 have respective upper ends 12c and 14a constricted in the shape of a nozzle, and accelerate the passing exhaust gas by converting it into a contracted flow. Further, a bottom plate portion 14b joined to the cylinder body 12 is provided at the lower part of the external cylinder body 14, and the bottom plate portion 14b functions as a bottom portion of the cavity 13. The bottom plate portion 14 is provided with a discharge pipe 16 for discharging water that has flowed into the cavity 13.

As shown in FIG. 3, the plurality of water droplet collecting plates 15 are arranged in parallel to each other via a connecting plate 17 that is vertically supported within the cylinder 12 and including the central axis of the cylinder 12. Supported by That is, the plurality of water droplet collecting plates 15 are regularly arranged on both sides of the connecting plate 17 as a boundary surface, thereby vertically dividing the interior of the cylinder 12 into a large number of sections.

Each water droplet collecting plate 15 divides the exhaust gas passage into a large number of passages and causes the exhaust gas passing through the passage to collide with a slope to catch water droplets that rise together with the exhaust gas.The configuration thereof is shown in Fig. 4. As shown in the figure, the slope parts 18 and 19 that cause the exhaust gas to collide are inclined in opposite directions to each other and are arranged alternately in the exhaust gas flow direction (vertical direction in the figure) to form a zigzag shape in the exhaust gas flow direction. , and on the front and back sides of the lowermost portions of the water bottle collecting plates 15 and the respective joining parts of the inclined slopes in mutually opposite directions, the collecting plates 15 are provided.
Drain groove 20 that collects water droplets attached to the surface side of
and a drain groove 21 that collects water droplets attached to the back side.
are provided for each. Note that each of these drain grooves 20 and 21 opens in the same direction as the upward flow direction of exhaust gas, and has an inclined end (lower end).
is electrically connected to the space 13. As shown in FIG. 2, the collection plate 15 having such a configuration has dimensions etc. selected so that one side protrudes from the opening 12b into the space 13, and has a diameter that extends from each drain groove 2.
For reasons such as allowing the water that collects in drain grooves 20 and 21 to flow into the cavity 13, the cavity 13 side is lowered to give each drain groove 20 and 21 an inclination angle θ. The angle of inclination of the slope portions 18 and 19 is set in consideration of pressure loss when exhaust gas collides with each other, and in this embodiment, it is approximately 45 degrees.

Regarding the stack crane prevention device 11 described above, an experimental device as shown in FIG. 5 was manufactured and an experiment was conducted.

First, let us explain the experimental apparatus shown in Figure 5.
A ventilation duct 23 is connected to the lower part of the chimney 10,
A damper 24 and a blower 25 are provided at the end of the blower duct 23, and the damper 24 and blower 25 create a state similar to the actual flow of exhaust gas. In addition, a spray nozzle 26 and a pump 27 that sends water to the spray nozzle 26 are provided at an intermediate height position of the chimney 10, and these spray nozzles 26 and pump 27 cause an overflow phenomenon (of the chimney 10). (This is a phenomenon in which a part of the water film formed on the inner peripheral surface peels off and becomes water droplets and scatters.) Water droplets that should have been formed are now formed.

In addition, in the above experimental equipment, the dimensions of each part are as follows:
As follows (units are millimeters) H ₁ (equipment height) = 1865, H ₂ (chimney height) = 4350, H ₃ =
400, H ₄ = 900, D ₁ (chimney diameter) = 760, D ₂ = 680, D ₃
= 1160, D ₄ = 1460 In addition, in the water droplet collecting plate shown in FIG. 4, the dimension C of the gap 28 between the collecting plates 15, 15 is C=50,
Length L ₁ of needle face parts 18, 19 = 141, drain groove 20
The width W ₁ =16.

In the above experimental apparatus, an experiment was conducted by generating water droplets with a diameter of about 0.52 mm from the nozzle 26.

The diameter of the water droplets formed in the experimental chimney is 0.5
mm to 3.5 mm, and the water droplets formed by the nozzle 26 are within that range and on the small particle size side. It is estimated that good results can be obtained even when installed in

Regarding the results of the experiment, the water droplets ejected from the nozzle 26 and rising inside the chimney 10 by the wind sent from the blower 25 are well captured by each collection plate 15, and are discharged from the drain pipe 16 into the chimney. It was discharged to the outside for 10 minutes, and no stacclain occurred.

In other words, regarding this result, in the experimental device, the height dimension of the stack crane prevention device 11 was
H ₁ is approximately 25 times the diameter D ₁ of the chimney 10, making it possible to prevent stack rain with less than half the size of the conventional device.

The function of the stack rain prevention device 11 to trap water droplets will be considered as follows.

Water droplets formed at the lower part of the chimney 10 due to the overflow phenomenon (nozzle 26 in the experiment) rise inside the chimney 10 together with the exhaust gas as in the conventional case, but the water droplets formed on the adjacent water droplet collection plate 15, When passing through the gap 28 between the collecting plates 15 (see FIGS. 3 and 4), the exhaust gas collides with the front and back surfaces of each of the collecting plates 15, 15, especially the slope portions 18, 19,
The water droplets that have risen together with the exhaust gas due to this collision adhere to the slope portions 18, 19, and the like. The water droplets adhering to these slope parts 18 and 19 are collected by the water droplet collecting plate 1
The flow velocity passing through the gap 28 between 5 and 15 is
Since the flow rate is smaller than the flow rate inside the chimney 10, it is difficult to peel off compared to when it adheres to the substantially vertical inner circumferential surface of the chimney 10, and it sequentially travels along the slope parts 18 and 19 and is collected in the drain grooves 20 and 21. It flows into the cavity 13 as shown by the broken line in FIG. 2, and is discharged to the outside of the chimney 10 through the drain pipe 16.

On the other hand, most of the exhaust gas from which water droplets have been removed by the collection plate 15 rises within the cylinder 12, is accelerated by the nozzle-shaped upper end 12c, and is discharged, but some of the exhaust gas When passing through the gap 28, it flows into the space from the opening 12b of the cylinder 12, and the space 1
3 and is accelerated at the upper end 14a of the outer cylinder 14 and discharged. In addition, at this time (when the exhaust gas flows into the space 13 from the opening 12b), the exhaust gas flow produces an effect of drawing out and discharging the collected water flowing out from the drain grooves 20 and 21, and the collected water flows from the drain grooves 20 and 21. It has the effect of encouraging and promoting drainage of collected water. Moreover, in the embodiment, a phenomenon occurs in which the exhaust gas is drawn out from the cavity 13 by the action of the exhaust gas flow passing through the cylinder 12 and blowing through the upper opening thereof.
It has the effect of further promoting the action of drawing in and discharging. Furthermore, the exhaust gas rising inside this space 13 warms the peripheral wall of the cylinder 12 and
This produces the effect of preventing moisture in the exhaust gas from condensing on the inner circumferential surface of No. 2.

Also, as in the previous experiment, the size of the device
The reason why it costs less than half of the conventional one is that the collection plate 15, which serves as a means for capturing water droplets, is provided so that the inside of the cylinder 12, which serves as a passage for exhaust gas, is vertically divided, so it is less susceptible to rising exhaust gas. Even if the number of collection plates 15 is increased to densely divide the inside of the passage, the pressure loss will not become so large.
9 are formed in multiple stages in the flow direction of exhaust gas,
Water droplets that fail to adhere to the lowermost slope part 18 have the opportunity to be captured by the upper slope part 19, and the drain grooves 20 and 21 provided on both sides of the joining part of the slope part and both sides of the lowermost part have the opportunity to be captured. Therefore, the slope portion 18,
Since the water droplets captured on both sides of the tube 19 are collected and drained to the outside of the cylinder through the plurality of drain grooves 20 and 21, it is considered that the water droplets can be efficiently captured in a short ascending distance. In the embodiment, a plurality of water droplet collecting plates 1 vertically partition the inside of the cylindrical body 12.
5 are regularly arranged in the cylinder body 12 to divide the exhaust gas passage into many sections, so that all the exhaust gas passing through the cylinder body 12 hits the water droplet collection plate 15, and the water droplets that have risen together with the exhaust gas are removed. This water droplet collection plate 15 reliably collects the water droplets, and drains the water droplets into the drain grooves 20 and 21 provided on both surfaces of the joining portions and the bottom portions of the slope portions 18 and 19, respectively.
Since water is collected on the slopes and drained outside the cylindrical body 12, the water droplets collected on the slopes 18 and 19 are allowed to drip down to the drain groove at the bottom, or the water droplets are collected on the slopes 18 and 19 to the drain groove at the bottom. There is no need to conduct water droplets to drain them, and water droplets can be efficiently drained to the outside of the cylindrical body, thereby improving the water-capturing ability. Therefore, there is an effect that water droplets can be efficiently captured in a short ascending distance. In addition, since the water droplets are collected by the drain grooves 20, 21 after traveling only a short distance between the collected slope portions 18, 19, there is less risk that the collected water droplets will be rolled up by the exhaust gas on the way. There is also the advantage of being able to do so.

In order to investigate the effect on the soot contained in the exhaust gas and the peeled pieces of the lining material attached to the inner peripheral surface of the chimney 10, the chimney 1 was measured using the apparatus shown in FIG.
When sand was mixed in from the bottom of the bottle, it was found that sand could be collected well. The collected sand is
Together with the water, it was discharged from the collection plate 15 to the cavity 13 and from the cavity 13 to the drain pipe 16. From this result, it was found that even if powder was mixed in the exhaust gas, the water droplet trapping effect did not decrease, and moreover, the powder itself could be captured.

Although one embodiment has been described above, the structure of the collection plate 15 itself and the mutual arrangement of the collection plates 15 are not limited to the above-described embodiment. For example, as shown in FIGS. 6 and 7, the connecting plate 17 may not be used, and both ends of the collection plate 15 may be directly supported by the cylindrical body 12. Furthermore, as shown in FIG. 8, collection plates 15 may be provided radially around the cylindrical connecting member 29.

Furthermore, the water droplet collecting plate can be improved as shown in FIG.

The water droplet collecting plate 30 in FIG. 9 is provided with a gutter 31 at the top of the slopes 18 and 19 where water droplets collide.
Moreover, by lengthening the upper edges of the slope parts 18 and 19, a V-shaped drain groove 33 is formed between the upper parts of the slope parts 18 and 19 and the joined vertical wall 32.

As shown in FIG. 10, the gutter 31 has an arcuate cross section with about 1/4 of the circumference cut out.
The slope portion 18 is inserted into the gutter 31 from the opening 31a,
The slope part 1 is designed so that the upper edge of the gutter 31 protrudes, and a gap is left between the lower end 31b of the gutter 31 and the slope parts 18 and 19 through which exhaust gas can flow.
It is attached to the top of 8 and 19.

The collection plate 30 having such a structure is suitable when the flow rate of exhaust gas is faster than the collection plate 15 shown in FIG. 4. The reason for this is that as the flow velocity of the exhaust gas is gradually increased, the overflow phenomenon also occurs on the slope section 18, etc., but even if separation occurs on the slope section 18 in this way, the phenomenon shown in Fig. 9 Then, the water droplets separated from the slope portion 18 rise along the slope portion 18 together with the exhaust gas and flow into the gutter 31, collide with the inner circumferential surface of the gutter 31, and are captured. The captured water droplets flow through the inner bottom 31c (see FIG. 10) of the gutter 31 and flow into the cavity 13, so that even when the flow rate of exhaust gas is high, capture and leakage is unlikely to occur.

When conducting an experiment using the collection plate 30 shown in Fig. 9 with an experimental apparatus similar to that shown in Fig. 5, the one shown in Fig. 9 performed well until the flow velocity reached 7.57 m/s. was able to capture water droplets. on the other hand,
In the structure shown in FIG. 4, the critical flow velocity at which water droplets could be captured was 5.73 m/s. Therefore, by providing the gutter 31 as shown in Fig. 9,
This means that the critical flow velocity has improved by approximately 32%. If the critical flow velocity can be improved in this way, when processing a certain amount of exhaust gas, the diameter of the chimney can be reduced by the amount of increased flow velocity, which corresponds to a reduction in the diameter of the chimney. As a result, the stack crane prevention device 11 itself can be made more compact.

In the above experiments, the inclination angle θ of the capture plate shown in Fig. 2 was set to θ = 10°.
By setting θ to a more appropriate value, it is possible to further improve the water droplet trapping performance and to achieve further compactness. For example, if we use the collection plate 30 shown in FIG. 9 and have the structure shown in FIGS. 6 and 7, θ
When θ=15°, the critical flow velocity Vmax was 7.62 (m/s), but when θ=20°, Vmax10.0 (m/s) was obtained.

As explained above, the stack crane prevention device of the present invention is provided with a plurality of water droplet collecting plates vertically partitioning the cylinder inside the cylinder that connects to the top of the chimney and serves as a passage for exhaust gas. The collection plate is used as a means for trapping water droplets that rise together with the exhaust gas. It has a zigzag configuration in the flow direction, and there is also a drain groove at the bottom of the water droplet collection plate and the slanted surface where they meet to collect water droplets that have adhered to the front surface of the slope, and a drain groove that collects water droplets that have adhered to the back side of the slanted surface. Since the water droplets collected by the drain grooves are drained to the outside of the cylinder body, the following effects are achieved.

All the exhaust gas passing through the cylinder hits the water droplet collection plate, and the water droplets that rise with the exhaust gas can be reliably collected by the water droplet collection plate. It's not that much of a resistance.

The front and back sides of the water droplet collection plate perform the water-catching function, and water droplets that fail to adhere to the bottom slope have the opportunity to be captured by the upper slope, making it possible to capture them extremely efficiently over a short ascending distance. can.

The water droplets captured on each slope are collected by the drain grooves provided on both sides of the joining part and the bottom of the slope, so water droplets are extremely efficiently drained to the outside of the cylinder on each slope. can do.

As a result of the above-mentioned effects, compared to a conventional device in which a porous moisture-absorbing material is attached to the inner circumferential surface of the cylindrical body and the moisture-absorbing material is used as a means for capturing water droplets, the collision efficiency of exhaust gas is high, and the efficiency is less than half that of the conventional device. The height dimension makes it possible to prevent static cranes.

In other words, in the present invention, drain grooves are provided on the lowermost part of the water droplet collecting plate and on the front and back sides of each joining portion of the slope portions inclined in opposite directions to each other to collect water droplets adhering to the surface side of the slope portion, and on the back surface side. Since the water droplets are each provided with a drain groove that collects water droplets attached to the slope, the water droplets can be collected by the drain groove after being transmitted only a short distance on the slope where they were collected. It is possible to efficiently capture water droplets at a distance and improve water capture ability.

In addition, in the present invention, because drain grooves are provided on both the inner and outer surfaces of each mating part of the slope, water that collides with the slope becomes larger water droplets while descending or rising toward the drain groove. Even when I get old,
Since the water droplets are collected in the drain groove before they are released from the slope again, the water droplets may be released and dispersed from the slope due to the vibration of the collection plate, the upward flow of exhaust gas, etc. This improves its water-capturing ability and contributes to making the device more compact. The reason for this compact design is to take into account special construction and design considerations, such as the fact that the stack crane prevention device of the present invention is installed at the top of the chimney, requiring work at heights, and that the center of gravity is high. If this happens, the effect will be extremely important.

Further, according to the present invention, a part of the water droplet collecting plate is configured to protrude into the cavity from the opening formed in the peripheral wall of the cylinder body for separating the exhaust gas, so that the exhaust gas flows into the cavity from the opening. The flow is collected all at once by the collection plate, and the collected water that flows out from the drain groove is actively pulled out and discharged, promoting the discharge of the collected water from the drain groove and improving drainage. Furthermore, in the present invention, a phenomenon occurs in which exhaust gas is drawn out from the cavity by the action of the exhaust gas flow that passes through the cylinder and blows through its upper opening, so the collected water is drawn out and discharged. It has the effect of further promoting the action. Furthermore, in the present invention, by disposing an external cylinder around the outer periphery of the cylinder to form a double structure, in addition to promoting liquid discharge, it is also possible to prevent dew condensation on the cylinder. We are also creating a synergistic effect that allows us to improve the performance of stack crane prevention devices.

In addition, since the drain groove of the present invention opens in the same direction as the upward flow direction of the exhaust gas, the water flowing in the drain groove is affected by the upward flow wind pressure caused by the exhaust gas.
Problems such as difficulty in flow do not occur, and even when the flow rate of exhaust gas becomes high, there is no risk of overflowing inside the drain groove, and drain is reliably discharged.

As a result of the above-mentioned effects, the equipment can be downsized to less than half its size without sacrificing the effectiveness of preventing stack cranes, and the reduction in construction scale associated with this downsizing will result in a reduction in the size of the equipment. , it has become possible to shorten the construction period and reduce construction costs. In addition, due to the above-mentioned compactness, it becomes easier to adopt construction methods such as assembling the main parts or the entire device in the factory and installing the assembled product in the shape of an existing chimney. Therefore, it is possible to improve workability in construction work and further shorten the construction period.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a conventional stack crane prevention device, FIG. 2 is a side sectional view of an embodiment of the present invention, and FIG.
The figure is a sectional view taken along the - line in Figure 2, Figure 4 is a perspective view of the main parts in Figure 2, Figure 5 is a schematic configuration diagram of an experimental apparatus to which one embodiment is applied, and Figure 6 is the main part. 7 is a sectional view taken along the line - in FIG. 6; FIG. 8 is a sectional view of yet another embodiment of the invention; FIG. 9 is a sectional view taken along the line - in FIG. A perspective view showing another embodiment of the collection plate, FIG.
It is a side view of the main part in a figure. DESCRIPTION OF SYMBOLS 10...Chimney, 11...Stuck crane prevention device, 12...Cylinder body, 12a...Large diameter part, 12b...
...Opening, 12c...Top end, 13...Vacancy, 1
4...External cylindrical body, 14a...Upper end, 14b...
Bottom plate part, 15... Water droplet collection plate, 16... Drain pipe,
17... Connecting plate, 18, 19... Slope portion, 20,
21...Drain groove, 28...Gap, 29...Connection member, 30...Water droplet collection plate, 31...Gutter, 31a
...opening, 31b...lower end, 31c...inner bottom, 32...vertical wall, 33...drain groove.

Claims (1)

[Claims] 1. A cylinder 12 that is attached to the upper end of the chimney 10 and serves as a passage for exhaust gas, and a space 13 that covers the outer periphery of the cylinder 12 concentrically to form an upwardly open space 13 between the cylinder and the drain pipe. an outer cylinder 14 having 16;
A plurality of water droplet collecting plates 15 are provided which partition the inside of the cylinder vertically and protrude into the space 13 from an opening 12b formed in the circumferential wall of the cylinder at least on one side and which separates the exhaust gas. A plurality of water droplet collection plates 15 are regularly arranged in the cylinder body to divide exhaust gas passages into a large number of passages, and each water droplet collection plate 15 has a slope portion 1 that collides with the exhaust gas.
8 and 19 are arranged in a zigzag shape in the flow direction of the exhaust gas in such a manner that they are inclined in opposite directions to each other, forming a zigzag shape in the flow direction of the exhaust gas, and one side facing the cavity 13 is held in the cylinder with a downward slope. Furthermore, drain grooves 20 are provided on the front and back surfaces of the lowermost part of the water droplet collecting plate 15 and the joint portions of the slope portions inclined in opposite directions to each other to collect water droplets adhering to the surface side of the slope portions, and drain grooves 20 are provided on the back surface side. Drain grooves 21 are provided to collect attached water droplets, and these drain grooves 20 and 21 are opened in the same direction as the upward flow direction of the exhaust gas, and their inclined ends are connected to the space 13. A static crane prevention device characterized by: