JPH0834395A - Smoke stack for ship - Google Patents

Abstract

PURPOSE:To prevent air pollution by smoke by making in-ship combustion gas exhausted from the inner tube of a smokestack into a turning flow by spiral fins installed projectedly on the inside wall of the inner tube and guiding it upward taking care so that it is not caught into a turbulent area. CONSTITUTION:The combustion gas led from a combustion gas exhaust part in a ship during cruising into the inner tube 3 of a smokestack through a duct is guided to spiral fins 4 installed projectedly on the inside wall of the inner tube 3 while it passes the inner tube 3. By this, the combustion gas becomes an exhaust flow to which a turning component is given, and rises as a turning flow through the inside of the inner tube 3. Then, even if it is exhausted to a turbulent area formed at the rear of a hull upper structure part, it is not diffused into the turbulent area, and can flow upward after breaking through a turbulent area boundary surface. Also the inclined angle of the spiral fins 4 is most suitable at approx. 30 to 45 deg. for the exhaust flow to become an upward air flow.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chimney used for ships.

[0002]

2. Description of the Related Art There is a conventional ship chimney as shown in FIG. 5, which includes an outer cylinder 2 erected on the upper part of a hull 1, and an inner cylinder 3 arranged inside the outer cylinder 2. The chimney is configured by the inner cylinder 3 through the duct 3a, and the engine and the boiler onboard the ship.
11 is connected to the combustion gas exhaust.

The inner cylinder 3 requires a "penetration" projecting upward from the turbulent flow region boundary surface 8 which is generated rearward from the upper front edge of the hull upper structure 6 which receives the wind W during navigation. Thus, the exhaust flow 7 from the inner cylinder 3 is prevented from being caught in the turbulent flow region and the diffused gas of the exhaust flow 7 is prevented from causing smoke damage to the inside of the ship through the ventilation pipe 5 and the window of the ship. In addition,
Reference numeral 9 in FIG. 5 indicates a chimney inner deck, and 10 indicates a reinforcing material.

[0004]

By the way, in the conventional marine chimney as described above, the turbulent flow region boundary surface 8 also changes due to changes in wind strength and wind direction, and the exhaust flow 7 from the inner cylinder 3 changes. There is a risk of being caught inside and causing smoke damage. Therefore, it is conceivable that both the outer cylinder 2 and the inner cylinder 3 are made higher, or only the inner cylinder 3 is projected further upward. However, in this case, the size of the chimney is increased, the cost is increased, and the appearance is impaired. There is a problem.

The present invention is intended to solve the above-mentioned various problems. By giving a swirling component to the flow of the combustion gas flowing through the inner cylinder, the exhaust gas is surely prevented from being entrained in the turbulent flow region. It is an object of the present invention to provide a marine chimney that can be breached upward and can sufficiently prevent smoke damage from occurring.

[0006]

In order to achieve the above-mentioned object, a ship chimney of the present invention comprises an outer cylinder erected on a ship and a combustion gas in a ship via a duct arranged inside the outer cylinder. In a marine chimney composed of an inner cylinder connected to a discharge part, a spiral fin for discharging combustion gas from the inboard combustion gas discharge part as a swirl flow is projectingly provided on an inner peripheral wall of the inner cylinder. It is characterized by that.

[0007]

In the above-mentioned marine chimney of the present invention, the inboard combustion gas discharged from the inner cylinder of the chimney during the navigation of the ship is spirally projected on the inner peripheral wall of the inner cylinder when passing through the inner cylinder. Since the swirling component is given by the fins, the exhaust flow is directed upward as a swirling flow. Therefore, even if the exhaust flow is discharged into the turbulent flow region formed behind the upper hull structure, the exhaust flow as a swirl flow will flow upward without being diffused in the turbulent flow region.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A marine chimney as an embodiment of the present invention will be described below with reference to the drawings. FIG.
4 is a perspective view of the main part thereof, FIG. 3 is a longitudinal sectional view of the inner cylinder thereof, and FIG.
FIG. 4 is a plan view of the inner cylinder of FIG. 3. As shown in FIG. 1, a chimney is formed by an outer cylinder 2 provided upright on the upper portion of a hull 1 and an inner cylinder 3 arranged inside the outer cylinder 2, and the inner cylinder 3 is provided with a duct 3
It is connected via a to the combustion gas discharge part such as the engine and the boiler 11 in the ship.

The upper end position of the inner cylinder 3 is set at a level lower than that of the turbulent flow area boundary surface 8 generated rearward from the upper front edge of the hull upper structure 6 receiving the wind W during navigation. In order for the exhaust flow 7 from the inner cylinder 3 to be discharged into the turbulent flow region as a swirling flow, the inner peripheral wall of the inner cylinder 3 is spiraled as shown in FIGS. Fin 4
Is protruding. The inclination angle of the spiral fin 4 is preferably about 30 to 45 degrees in consideration of the effect that the exhaust flow 7 becomes an upward flow. Reference numeral 5 in FIG. 1 indicates a ventilation tube installed near the chimney, reference numeral 9 indicates an inner deck of the chimney, and 10 indicates a reinforcing material.

Since the marine chimney of the present invention is constructed as described above, the combustion gas introduced from the combustion gas discharge part in the vessel to the inner cylinder 3 of the chimney through the duct 3a during navigation of the vessel is
When passing through the inner cylinder 3, while being guided by the spiral fins 4 projecting on the inner peripheral wall of the inner cylinder 3, the exhaust flow 7 is given a swirling component as shown in FIG. Three
The exhaust flow 7 discharged from the air flows upward as a swirling flow. Therefore, even if the exhaust flow 7 as the swirling flow is discharged to the turbulent flow region formed behind the upper hull 6 of the hull, the exhaust flow 7 does not diffuse in the turbulent flow region and passes through the turbulent flow region boundary surface 8. It breaks through and goes upward.

As described above, in the marine chimney of this embodiment, even if the upper end position of the inner cylinder 3 of the chimney is set to a level lower than the turbulent flow area boundary surface 8, the exhaust gas flow 7 is passed through the ventilation tube 5 and the ship window. The diffused gas does not flow into the ship to cause smoke damage to passengers, and the height of the outer cylinder 2 and the inner cylinder 3 can be made lower than that of the conventional chimney, so that the chimney can be downsized.

[0012]

As described above in detail, the marine chimney of the present invention has the following effects. (1) Since the spiral fins are provided on the inner peripheral wall of the inner cylinder of the chimney, the exhaust flow from the inner cylinder is discharged as a swirl flow, so the turbulent flow area behind the hull upper structure. Even if the exhaust flow is discharged to the above, the exhaust flow does not diffuse and breaks through the boundary surface of the turbulent region and goes upward, thereby preventing smoke damage to the inside of the ship. (2) Since the upper end position of the inner tube of the chimney can be set to a level lower than the boundary surface of the turbulent region, the inner tube and the outer tube of the chimney can be lowered to downsize the chimney.

[Brief description of drawings]

FIG. 1 is a side view showing a ship chimney as one embodiment of the present invention.

FIG. 2 is a perspective view of a main part of the marine chimney of FIG.

FIG. 3 is a vertical sectional view of an inner cylinder of the marine chimney shown in FIGS.

FIG. 4 is a plan view of the inner cylinder of FIG.

FIG. 5 is a side view showing a conventional marine chimney.

[Explanation of symbols]

 1 Hull 2 Outer Cylinder 3 Inner Cylinder 3a Duct 4 Spiral Fin 5 Ventilation Cylinder 6 Hull Upper Structure 7 Exhaust Flow 8 Turbulent Area Boundary 9 Chimney Inner Deck 10 Reinforcement 11 Engine or Boiler W Wind

Claims (1)

[Claims] 1. A marine chimney comprising an outer cylinder erected on a ship and an inner cylinder arranged inside the outer cylinder and connected to an inboard combustion gas discharge portion via a duct, wherein A marine chimney, characterized in that spiral fins for projecting the combustion gas from the inboard combustion gas discharge section as a swirling flow are provided on the inner peripheral wall.