JPS626246Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an exhaust gas purification device for a small marine diesel engine.

[Conventional technology and its problems]

As is well known, the gas discharged from a diesel engine contains aldehydes, which are partly discharged as unburned gas, and this produces a pungent odor. Such irritating odors are often generated when the engine is in a steady state with low output, when the engine is idling, or when the engine is started.

As countermeasures, various proposals have been made as follows. That is, when the temperature of the exhaust gas falls below the set value during idling operation, the exhaust valve installed in the exhaust pipe is closed and the heater installed between the exhaust valve and the engine body is heated. An exhaust gas purification device for removing irritating odor components contained in exhaust gas has been proposed (Japanese Utility Model Publication No. 52-25526).

However, with such a device, engine output cannot be obtained because the exhaust pipe is closed by the exhaust valve during idling operation.

In addition, the muffler installed on a diesel engine consists of a normally used muffler and a muffler for removing irritating odors, these mufflers are installed side by side, and an exhaust valve is installed at the inlet of each muffler. An exhaust gas purification system for diesel engines for vehicles is designed to close the exhaust valve of the muffler used and open the exhaust valve of the purification muffler, and during normal operation, open the exhaust valve of the muffler normally used and close the exhaust valve of the purification muffler. It has been proposed (Utility Model Publication No. 52-31872).

However, in this proposal, since the exhaust gas purification device is composed of two pipes that discharge exhaust gas into the atmosphere, if the exhaust gas purification device is applied to a small marine diesel engine, it would occupy space inside the ship, which is undesirable.

[Means for solving problems]

Therefore, the present invention aims to completely eliminate the various disadvantages of these conventional techniques and provide an exhaust gas purification device suitable for small marine diesel engines. We have measures like this.

That is, an approximately U-shaped bypass with a smaller diameter is attached to an exhaust pipe attached to a small diesel engine, an exhaust valve is installed in the exhaust pipe, and the bypass is communicated with the exhaust valve sandwiched therebetween. ,
The bypass is therefore rejoined further downstream of the exhaust valve. Furthermore, a small marine diesel engine is provided in which a liquid that absorbs aldehydes in the exhaust gas is interposed in the middle of the bypass, and the exhaust valve is closed only when the engine output is low to allow the exhaust gas to pass through the bypass. This is an exhaust gas purification device.

[Effect]

Since the exhaust valve is closed during low output (idling), exhaust gas passing through the exhaust pipe enters the bypass through the bypass inlet and comes into contact with the absorption liquid. The purified exhaust gas then reenters the exhaust pipe from the bypass outlet and is discharged to the atmosphere. During normal operation (at rated output), the exhaust valve is open, so
Most of the exhaust gas is directly discharged into the atmosphere without passing through the bypass. Therefore, the purpose of the present invention can be achieved by such action.

〔Example〕

Hereinafter, the configuration of the present invention will be explained in detail with reference to embodiments shown in the accompanying drawings.
Two embodiments are shown, and the same parts are designated by the same reference numerals.

In Fig. 1, 1 is an exhaust pipe installed vertically in a small marine diesel engine, 2 is an exhaust valve provided in the exhaust pipe 1, and a bypass with a diameter smaller than the exhaust pipe 1 is provided immediately before the exhaust valve 2. An inlet 3 is provided, a bypass 4 communicating with the bypass inlet 3 is formed in a U-shape, and an absorbent outlet 6 is provided at the lowest position of the bypass 4.
The bypass 4 is provided with a spout 5 for absorbing liquid at the upper part thereof. The outlet 7 of the bypass 4 is provided downstream of the exhaust valve 2. Therefore, during normal operation, set the exhaust valve 2 to position A in the figure.
At low output, do this manually so that it is in position B. Of course, this operation may be performed automatically via a device that is linked to the rack position of the fuel injection pump, the regulator position, or the engine speed of the diesel engine. Therefore, during low output (idling), exhaust gas passing through the exhaust pipe 1 enters the bypass 4 from the bypass inlet 3 and comes into contact with the absorption liquid spouted from the absorption liquid inlet 5. Then, the absorption liquid is discharged from the absorption liquid outlet 6, and the purified exhaust gas reenters the exhaust pipe 1 from the bypass outlet 7 and is discharged to the atmosphere. Since the exhaust valve 2 is in the A position during normal operation, most of the exhaust gas is exhausted to the atmosphere without passing through the bypass 4.

The aldehydes (mainly bomaldehyde) discharged during idling are dissolved in the liquid (water) to become formalin and discharged from the absorption liquid outlet 6 into the water.

In the second embodiment shown in FIG. 2, reference numeral 8 denotes an absorption liquid tank, and the structure is such that the absorption liquid tank 8 is suspended from a bypass 4, and the bypass 4 is inserted into the liquid. 9 is an absorption liquid inlet, and 10 is an absorption liquid outlet.

In the third embodiment shown in FIG. 3, a tank is suspended in the middle of the bypass 4, and the absorbent inlet 5 is directed toward the exhaust gas outlet in the tank. Note that 6 is a liquid outlet.

In the fourth embodiment shown in FIG. 4, a tank is suspended in the middle of the bypass 4, and a wire mesh 1 is placed inside the tank.
1, and the tank is provided with an absorption liquid inlet 5 and an absorption liquid outlet 6.

As the absorption liquid, water or a liquid that easily absorbs aldehyde, which is a known catalyst, is used.

In summary, the present invention adopts the structure described in the claims for utility model registration, and therefore has the following effects.

[Effect of idea]

Only during idling or at low power (and therefore when back pressure allows poor engine power), especially high aldehydes are brought into contact with easily absorbed liquids such as water, which removes pungent odors and removes HC. , it absorbs unburned gas like an underwater muffler, reduces the emission of blue-white smoke and odor, does not come in contact with liquid at rated output, and therefore does not reduce engine output. Overall, it is extremely rational. It can be made into a device.
In addition, a bypass with a smaller diameter and approximately U-shaped is installed in the middle of the diesel engine's exhaust pipe,
Since the exhaust pipe is merged downstream again, the aldehyde absorbing liquid can be easily interposed in the bypass, resulting in a simple structure and most of the exhaust gas can be purified. Moreover, good contact between the liquid and the exhaust gas is achieved, and in addition, it is possible to provide a small, compact, simple, and inexpensive exhaust gas purification device that does not take up space in the ship's engine room. .

[Brief explanation of the drawing]

Fig. 1 shows a first embodiment of the present invention, Fig. 2 shows a second embodiment, Fig. 3 shows a third embodiment, and Fig. 4 shows a fourth embodiment. 1 ... exhaust pipe, 4 ... bypass.

Claims (1)

[Scope of utility model registration request] A substantially U-shaped bypass with a smaller diameter is attached to the side of an exhaust pipe attached to a small diesel engine, and an exhaust valve is provided in the exhaust pipe on the downstream side of the inlet of the bypass, and the bypass is connected to the exhaust pipe. Further downstream of the exhaust valve, the exhaust gas is joined again, a liquid that absorbs aldehydes in the exhaust gas is interposed in the middle of the bypass, and the exhaust valve is closed only when the engine output is low, so that the exhaust gas passes through the bypass. Exhaust gas purification device for small marine diesel engines.