JPH0531394Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a swirl vane that is disposed inside a chimney for discharging exhaust gas from a boiler or the like and is used to swirl the exhaust gas.

[Conventional technology]

The scattering of mist from the top of the chimney (known as static rain) due to the drop in boiler exhaust gas temperature has resurfaced as an environmental problem, and a mist removal device has been installed at the top of the chimney to collect the mist. It has become necessary to do so.

In order to remove mist at the top of the chimney, it is more efficient to first allow the mist contained in the exhaust gas to adhere to the inner wall of the chimney, and then install a device that removes this adhering mist.

In FIGS. 5 to 9, the swirl vane 01 is
It is arranged inside a chimney 07 that discharges exhaust gas 06 from a boiler 05 or the like, and gives swirl to the exhaust gas. A plurality of the swirling vanes 01 are fixedly arranged between an outer ring 02 having a length l defining the outer circumference and an inner ring 03 arranged concentrically at the center of the outer ring 02. The shape of the swirling vane 01 is as shown in the developed views of FIGS. 7 and 8.

[Problem that the invention attempts to solve]

According to the known technology as described above, the swirl vane 01
As can be seen from FIGS. 7 and 8, the arrangement pitch in the circumferential direction is wide near the outer periphery and narrow near the center.

This means that the flow 06 of exhaust gas, etc. easily flows toward the outer circumference, but it is difficult to flow toward the center, and the flow that has uniformly flowed through the chimney 07 until just before the swirl vane 01 flows to the outer circumference when it flows into the swirl vane 01. As a result, the water droplets that had adhered to the inner wall of the chimney were scattered again, reducing the collection efficiency.

[Means for solving problems]

Equalizes the circumferential velocity of the entire gas flow area in the center of the chimney,
In addition, an intermediate ring is installed between the inner ring and the outer ring, and a blade is placed between the inner ring and the intermediate ring for the purpose of causing the mist in the central gas flow to adhere to the inner wall of the chimney using centrifugal force. The arrangement pitch of the swirling vanes between the center part and the outer peripheral part is made to be approximately the same as the pitch of the swirling vanes arranged between the outer ring and the intermediate ring.

[Effect]

By reducing the number of blades between the intermediate ring and the inner ring, the amount of exhaust gas flowing between them increases and the peripheral speed increases, making it easier for mixed mist to adhere to the inner wall of the chimney. In addition, the exhaust gas between the intermediate ring and the outer ring is not pressed strongly against the outer ring side, that is, the inner wall of the chimney, as in the conventional case, and the flow velocity is not so high that it causes the mist to scatter again, and the mist is collected. Increased efficiency.

〔Example〕

In Figures 1 to 4, 2 is an outer ring, 3 is an inner ring, 6 is an exhaust gas, and 10 is a swirl vane, which has a length of about 60% of the diameter of the outer ring 2 that defines the outer circumference. A plurality of rings are fixedly arranged between intermediate rings 13 whose diameter is . Further, 11 is also a swirling vane, which is fixed between the intermediate ring 13 and the inner ring 14, and has half the number of swirling vanes 10.
Moreover, the inlet sides of the flow 15 of exhaust gas etc. are arranged so that every other sheet is aligned.

FIG. 10 shows the above action as a circumferential velocity distribution diagram of the exhaust gas discharged from the swirl vane.

The dotted line shows the circumferential speed distribution in a conventional swirling blade, and the closer to the outer ring 2 the circumferential speed increases.

The solid line shows how the peripheral speed on the inner surface of the intermediate ring 13 increases and decreases on the inner surface of the outer ring 2.

[Effect of idea]

With the proposed swirling vane, the exhaust gas containing mist in the central part of the swirling vane increases in circumferential velocity and quickly reaches the chimney wall surface due to centrifugal force, and adheres thereto, while the circumferential velocity decreases and adheres to the outer circumferential part of the swirling vane. It is possible to prevent the mist from dispersing again, and as a result, improve the collection rate of the mist in the exhaust gas.

[Brief explanation of the drawing]

Fig. 1 is a plan view of an embodiment of the swirl vane for a chimney according to the present invention, Fig. 2 is a sectional view of Fig. 1, Fig. 3 is a developed view of Fig. 1, and Fig. 4 is a - of Fig. 1. This is a developed diagram. Fig. 5 is a plan view of the conventional device, Fig. 6 is a sectional view of Fig. 5, and Fig. 7 is a - of Fig. 5.
The developed view, FIG. 8, is a - developed view of FIG. FIG. 9 is a conceptual diagram of the chimney, and FIG. 10 is a circumferential velocity distribution diagram of exhaust gas exiting the swirl vane.

Claims (1)

[Scope of Claim for Utility Model Registration] In a swirl vane installed inside a chimney for discharging exhaust gas from a boiler, etc. and used to give swirl to the exhaust gas, an intermediate ring is arranged between an inner ring and an outer ring. A swirl vane for a chimney, characterized in that the number of swirl vanes arranged between the intermediate ring and the inner ring is half the number of swirl vanes arranged between the intermediate ring and the outer ring. .