JP2005002805A - Exhaust device for diesel engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust device for a diesel engine capable of preventing explosion by unburned gas by reducing temperature of unburned gas exhausted from the diesel engine or removing spark contained in exhaust gas. <P>SOLUTION: In this exhaust device for the diesel engine for leading exhaust gas exhausted from the diesel engine 1 into an exhaust silencer 9 through an exhaust pipe 2, the exhaust pipe 2 is branched into an exhaust pipe (flow-in pipe) 3 side and a bypass pipe 4, a water tank 7 in which water is filled onto an exhaust pipe (flow-in pipe) 3 side is attached, and a partition valve 8 is attached on the halfway of the bypass pipe 4. When the exhaust gas exhausted from the diesel engine 1 contains unburned gas, the partition valve 8 is closed so that the exhaust gas passes through water in the water tank 7. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an exhaust device for a diesel engine, and is particularly suitable for use as an exhaust device for a diesel engine used for driving a main pump in a pump machine station or other equipment for transferring, draining and pressurizing fresh water and other liquids. The present invention relates to an exhaust device.
[0002]
[Prior art]
When a diesel engine is started in a low-temperature environment during operation of the diesel engine, a sufficient temperature rise cannot be obtained in each cylinder of the diesel engine, resulting in poor combustion, and as a result, unburned gas may be generated. is there. Although this unburned gas depends on the shape of the exhaust pipe, it remains in the exhaust pipe, and when the diesel engine is started again, the unburned gas is ignited or the temperature of the unburned gas rises. There is a risk of detonation in the exhaust pipe. This detonation phenomenon is a very dangerous phenomenon because it is accompanied by a large shock wave and may cause not only great damage to the exhaust pipe or exhaust silencer, but also damage to surrounding people.
[0003]
For this reason, when starting a diesel engine in a low-temperature environment, a fuel pipe heater is installed to prevent a decrease in temperature so that unburned gas is not generated. It is necessary to take measures such as Further, when the startability cannot be improved, it is necessary to take measures to provide an exhaust fan facility for discharging unburned gas remaining in the exhaust pipe.
[0004]
As described above, in measures to improve the startability of diesel engines, it is necessary to install a fuel pipe heater for temperature drop prevention and to perform fuel control at the start, but when installing a fuel pipe heater, It is necessary to consider not only the fuel piping but also the heat retention of the fuel tank, and the equipment becomes expensive. Fuel control also requires modification of the diesel engine itself. Even if the startability of the diesel engine is improved by these means, it is difficult to completely prevent the generation of unburned gas, and there is no measure to prevent detonation when unburned gas is generated. Therefore, the danger associated with the above detonation cannot be prevented.
[0005]
Furthermore, in the measure for providing the exhaust fan in the exhaust pipe, mechanical equipment is added in the middle of the exhaust pipe, leading to a decrease in the reliability of the apparatus. In addition, this exhaust fan is required to be able to completely discharge unburned gas, but it is difficult to confirm this.
[0006]
[Problems to be solved by the invention]
The present invention has been made in view of the above points, and its purpose is to reduce the temperature of the unburned gas discharged from the diesel engine, or to separate the unburned gas and remove it from the exhaust gas. An object of the present invention is to provide an exhaust device for a diesel engine that can prevent detonation due to gas.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention described in claim 1 is directed to a diesel engine exhaust system that guides exhaust gas discharged from a diesel engine to an exhaust silencer through an exhaust pipe, and a liquid tank containing a liquid is attached to the exhaust pipe. The exhaust gas discharged from the diesel engine is configured to pass through the liquid in the liquid tank.
[0008]
As described above, since the exhaust gas is configured to pass through the liquid in the liquid tank, it is possible to cut off the sparks that cause detonation and to reduce the temperature of the exhaust gas including unburned gas. Therefore, detonation can be almost certainly prevented.
[0009]
Further, the invention according to claim 2 is the exhaust system for a diesel engine according to claim 1, wherein the exhaust pipe branches from a branch portion provided upstream from the liquid tank, and downstream from the liquid tank. A bypass pipe that joins at the provided junction is provided, and an open / close gate valve is attached in the middle of the bypass pipe.
[0010]
As described above, a bypass pipe is provided, and an open / close gate valve is attached in the middle of the bypass pipe, so when unburned gas is generated from the diesel engine, exhaust gas is led to the liquid tank and detonation In addition to shutting off the sparks that cause it, the temperature of the exhaust gas containing unburned gas can be lowered, and if no unburned gas is generated, the inside of the liquid containing the exhaust gas in the liquid tank It is possible to operate without exhausting the diesel engine without applying an extra load.
[0011]
The invention according to claim 3 is the exhaust system for a diesel engine according to claim 1, wherein the exhaust pipe branches from a branch portion provided upstream from the liquid tank, and is downstream from the liquid tank. Provided with a bypass pipe that joins at a junction provided in the exhaust pipe, a three-way switching valve attached to the branch portion of the exhaust pipe, and a check valve attached between the liquid tank and the junction. .
[0012]
As mentioned above, a bypass pipe is provided, a three-way switching valve is attached to the branching part, and a check valve is attached between the liquid tank and the merging part, so when unburned gas is generated from the diesel engine The exhaust gas can be guided to the liquid tank to cut off the sparks that cause detonation and the temperature of the exhaust gas including unburned gas can be lowered. Gas can be discharged without passing through the liquid contained in the liquid tank, and the diesel engine can be operated without excessive load.
[0013]
According to a fourth aspect of the present invention, there is provided an exhaust system for a diesel engine according to the second or third aspect, wherein the unburned gas detection means for detecting unburned gas in the exhaust gas discharged from the diesel engine. And when the unburned gas detection means detects unburned gas, the open / close gate valve is closed or the three-way switching valve is switched to the liquid tank side.
[0014]
As described above, the unburned gas detection means is provided, and when the unburned gas detection means detects the unburned gas, the open / close gate valve is closed or the three-way switching valve is switched to the liquid tank side. Accordingly, the exhaust gas passage route can be switched, detonation can be prevented, and when no unburned gas is generated, the diesel engine can be operated without applying an extra load.
[0015]
According to a fifth aspect of the present invention, in the exhaust system for a diesel engine according to the first aspect, the liquid tank is attached to a rear end portion of the exhaust pipe and is configured integrally with the exhaust silencer. Features.
[0016]
As described above, since the liquid tank and the exhaust silencer have an integrated structure, the bypass pipe is eliminated, and the entire exhaust device can be configured compactly.
[0017]
According to a sixth aspect of the present invention, in an exhaust system for a diesel engine that guides exhaust gas discharged from a diesel engine to an exhaust silencer through an exhaust pipe, unexhaust gas in the exhaust gas is separated into the exhaust pipe. Combustion gas separation means is provided.
[0018]
As described above, by providing the unburned gas separation means, unburned gas in the exhaust gas can be separated and removed, and the unburned gas is not led to the exhaust silencer.
[0019]
The invention according to claim 7 is the exhaust system for a diesel engine according to claim 6, wherein the unburned gas separation means includes a filter for unburned gas and a filter for burned gas, When the combustion gas is not less than a predetermined allowable value, the unburned gas filter is disposed in the exhaust pipe, and when the unburned gas in the exhaust gas is not more than the predetermined allowable value, the combustion gas filter is It is comprised so that it may arrange | position in the said exhaust pipe.
[0020]
As described above, the unburned gas separation means is configured to arrange an unburned gas filter or a combustion gas filter in the exhaust pipe depending on whether the unburned gas in the exhaust gas is greater than or equal to a predetermined allowable value. Therefore, when the unburned gas in the exhaust gas exceeds a predetermined allowable value, the unburned gas is not led to the exhaust silencer.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a first embodiment of an exhaust system for a diesel engine according to the present invention. In FIG. 1, an exhaust pipe 2 attached to the exhaust port of the diesel engine 1 is connected to an exhaust silencer 9. An exhaust pipe 6 is further attached to the exhaust silencer 9.
[0022]
The exhaust pipe 2 branches into an exhaust pipe (inflow pipe) 3 and a bypass pipe 4 in the middle, and the exhaust pipe (inflow pipe) 3 is in the liquid (water 10 in this embodiment) in the water tank (liquid tank) 7. It becomes the outflow pipe which discharges exhaust gas. A gate valve (open / close valve) 8 is attached in the middle of the bypass pipe 4. Further, an exhaust pipe (outflow pipe) 5 is attached to the water tank 7, and the exhaust pipe (outflow pipe) 5 merges on the downstream side of the bypass pipe 4 and the gate valve 8 to become one exhaust pipe 2. 9 is connected.
[0023]
Here, the water level (water surface) 10 a of the water 10 stored in the water tank 7 is positioned higher than the opening end of the exhaust pipe (inflow pipe) 3 and is lower than the opening end of the exhaust pipe (outflow pipe) 5. positioned. As a result, the exhaust gas released into the water from the exhaust pipe (inflow pipe) 3 is released onto the liquid surface in the water tank 7 by buoyancy and flows into the exhaust pipe (outflow pipe) 5. The positional relationship between the open ends of the exhaust pipe (inflow pipe) 3 and the exhaust pipe (outflow pipe) 5 and the water level 10a is not limited to the above, and as shown by the dotted line in the figure, the exhaust pipe (outflow pipe) The open end of 5 may be located lower than the water level 10a. In that case, the exhaust gas flows directly into the exhaust pipe (outflow pipe) 5 from the water. Reference numeral 13 denotes a scavenging valve. The scavenging valve 13 is used for scavenging the inside of the exhaust pipe 2, and is normally closed, and is opened and used only during scavenging.
[0024]
The operation of the exhaust device of the diesel engine having the above configuration will be described. As will be described in detail later, the exhaust system includes unburned gas detection means for detecting whether or not unburned gas is contained in the exhaust gas discharged from the diesel engine 1, and the partition The valve 8 is closed when the unburned gas detecting means detects unburned gas, and is opened when it is not detected. When complete combustion is not performed inside the diesel engine 1 when the diesel engine 1 is started and unburned gas is generated, the unburned gas detection means detects the generation of unburned gas and closes the gate valve 8. Here, the detection of unburned gas means that unburned gas exceeding the allowable value is detected in the exhaust gas.
[0025]
The details of the unburned gas detection means are as follows. The diesel engine is provided with a specified speed detector (not shown) that detects that the rotational speed has increased from 0 to a specified speed at the time of starting. And when this regulation speed detector does not operate by a fixed time from the start, the control which stops a diesel engine acts that some sort of failure has occurred in the diesel engine. Using this specified speed detector, when the specified speed detector is activated within a certain time from the start of the diesel engine, that is, when the diesel engine starts normally, it is assumed that no unburned gas is generated, Unburned gas detection means that unburned gas is generated when the specified speed detector does not operate after a certain period of time since the diesel engine starts, that is, when the diesel engine does not start normally It is. That is, when the specified speed detector is activated within a predetermined time from the start of the diesel engine, the gate valve 8 is opened to allow the exhaust gas to flow into the bypass pipe 4, and the predetermined speed detector has passed a predetermined time from the start of the diesel engine. However, when it does not operate, the gate valve 8 is closed, and the exhaust gas is introduced into the exhaust pipe (inflow pipe) 3 to be introduced into the water tank 7.
[0026]
Another example of the unburned gas detection means is a method for detecting the temperature of the exhaust gas. When the diesel engine 1 is normally started, the fuel is burned in the cylinder of the engine, so that the exhaust gas discharged from the diesel engine 1 becomes high temperature (about 400 ° C.). On the other hand, if the diesel engine 1 is not started normally, the fuel is not combusted sufficiently, and the exhaust gas contains unburned gas. Since the temperature of this unburned gas is lower than that of the combustion gas, measuring the temperature of the exhaust gas can detect whether the exhaust gas contains the unburned gas or the ratio of the unburned gas. it can. In this way, the unburned gas in the exhaust gas is detected based on the exhaust gas temperature. That is, the exhaust gas temperature is measured. When the exhaust gas temperature is equal to or higher than the predetermined temperature, the gate valve 8 is closed, and when the exhaust gas temperature is lower than the predetermined temperature, the gate valve 8 is opened.
[0027]
As described above, when unburned gas is generated (unburned gas exceeding the allowable value is included in the exhaust gas), exhaust gas containing this unburned gas is used to close the gate valve 8. The gas does not directly flow into the exhaust silencer 9 but flows into the exhaust pipe (inflow pipe) 3 and flows out from the exhaust pipe (inflow pipe) 3 into the water 10 inside the water tank 7. The exhaust gas released into the water 10 rises in the water 10 by buoyancy and is released onto the water surface 10 a in the water tank 7, flows into the exhaust pipe (outflow pipe) 5, passes through the exhaust pipe 2, and passes through the exhaust silencer 9. Then, it is discharged to the outside through the exhaust pipe 6. Here, when the open end of the exhaust pipe (outflow pipe) 5 is located below the water level 10 a, that is, when the open end of the exhaust pipe (outflow pipe) 5 is located in water, the exhaust gas is in the water 10. Directly into the exhaust pipe (outflow pipe) 5.
[0028]
The phenomenon that unburned gas burns in the exhaust pipe and leads to detonation is caused by ignition due to sparks in the exhaust gas, temperature rise of the unburned gas, etc., but the exhaust gas passes through the water like this By doing so, it becomes possible to remove the sparks in the exhaust gas and lower the temperature of the exhaust gas, so that detonation due to unburned gas can be prevented.
[0029]
On the other hand, when the diesel engine 1 is started up, if it is normally burned and no unburned gas is generated, the unburned gas detection means detects it and opens the gate valve 8. The exhaust gas passing through the exhaust pipe 2 does not flow into the exhaust pipe (inflow pipe) 3, passes through the bypass pipe 4, and is discharged to the outside through the exhaust silencer 9 and the exhaust pipe 6. As a result, when the diesel engine 1 is operating normally, the exhaust gas passes through the bypass pipe 4 with a small head loss and does not pass through the water in the water tank 7, so an extra load is applied to the diesel engine 1. It becomes possible to drive without applying.
[0030]
Since the water tank 7 is attached in the middle of the exhaust pipe 2 as described above, when the exhaust device is maintained, the water 10 in the water tank 7 may be replaced, and the operation can be easily performed. When scavenging unburned gas accumulated in the exhaust pipe 2, scavenging in the exhaust pipe 2 can be performed by opening the scavenging valve 13 that is normally closed.
[0031]
The means for attaching the water tank 7 in the middle of the exhaust pipe is attached to the water tank 7 in the middle of the existing exhaust pipe as compared with the conventional means for installing a device such as a wind fan in the middle of the exhaust pipe, which is a countermeasure against unburned gas. This can be done easily, leading to reduced installation costs. Note that by allowing the exhaust gas to pass through the water, it is possible to remove the soot contained in the exhaust gas, which is effective in preventing pollution.
[0032]
The unburned gas detection means is a means for detecting unburned gas from the operating state at the rotational speed of the diesel engine after a certain time from the start of the diesel engine 1 as described above, or by measuring the temperature of the exhaust gas. It is not limited to means for detecting unburned gas, and any means that can detect unburned gas in exhaust gas may be used.
[0033]
FIG. 2 is a diagram showing an exhaust device for a diesel engine according to a second embodiment of the present invention. The second embodiment is different from the first embodiment in that it is replaced with a gate valve 8 installed in the middle of the bypass pipe 4 at a branch point between the exhaust pipe (inflow pipe) 3 and the bypass pipe 4 in three directions. A switching valve 12 is attached, and a check valve 11 is attached in the middle of the exhaust pipe (outflow pipe) 5, that is, between the water tank 7 and the junction of the bypass pipe 4 and the exhaust pipe (outflow pipe) 5. When the unburned gas detecting means detects the unburned gas by the unburned gas detecting means (not shown) as in the case of the gate valve 8 of the first embodiment, the three-way switching valve 12 is connected to the exhaust pipe. (Inflow pipe) 3 is switched to the direction. That is, when unburned gas is detected by the unburned gas detection means, the exhaust gas is guided in the direction of the exhaust pipe (inflow pipe) 3 and released into the water in the water tank 7. If unburned gas is not detected, the three-way switching valve 12 switches to the direction of the bypass pipe 4.
[0034]
At this time, the exhaust gas that has passed through the bypass pipe 4 does not flow back from the exhaust pipe (outflow pipe) 5 to the water tank 7 because the check valve 11 is attached to the exhaust pipe (outflow pipe) 5. As it is, it passes through the exhaust silencer 9 and is discharged from the exhaust pipe 6 to the outside. Therefore, while the diesel engine 1 is operating normally, the exhaust gas does not pass through the water inside the water tank 7, so the temperature of the water 10 inside the water tank 7 due to the high-temperature exhaust gas is increased. 10 evaporation can be reduced, and the frequency of replenishing the water 10 to the water tank 7 can be reduced, and the maintenance is simplified.
[0035]
In the second embodiment as well, when unburned gas accumulated in the exhaust pipe 2 is scavenged as in the first embodiment, scavenging is performed by opening the scavenging valve 13, which is normally closed. Can be done.
[0036]
FIG. 3 shows an exhaust system for a diesel engine according to a third embodiment of the present invention. In the third embodiment, the water tank 7 is attached to the rear end of the exhaust pipe 2 so as to be integrated with the exhaust silencer 9. That is, the exhaust pipe 2 is connected to the water tank 7, and an exhaust pipe (outflow pipe) 5 is attached to the wall surface of the water tank 7 on the exhaust silencer 9 side so that exhaust gas from the water tank 7 enters the exhaust silencer 9 and passes through the exhaust pipe 6. It is configured to be discharged to the outside. The open end of the exhaust pipe (outflow pipe) 5 may be positioned lower than the water level 10a in the water tank 7, as indicated by a dotted line in the figure.
[0037]
In this exhaust device, exhaust gas is discharged from the exhaust pipe 2 into the atmosphere in the water tank 7, passes through the water 10 in the water tank 7, flows into the exhaust pipe (outflow pipe) 5, and is discharged to the exhaust silencer 9. The At this time, by providing the partition plate 15 so as to reach the water from the ceiling surface of the water tank 7, the exhaust gas discharged onto the water surface 10 a in the water tank 7 passes through the water and the exhaust pipe (outflow pipe) 5. Discharged from. In the case of the present embodiment as well, when unburned gas is accumulated in the exhaust pipe 2, the unburned gas can be discharged by opening the scavenging valve 13.
[0038]
By adopting the above-described configuration, the water tank 7 and the exhaust silencer 9 are integrated, and the bypass pipe 4 and the gate valve 8 in the first and second embodiments are eliminated, so that the exhaust system is compact. Therefore, the reliability and workability of the exhaust device are improved. Further, compared with the conventional means for installing a device such as an exhaust fan in the middle of the exhaust pipe, the attachment is easy and the reliability of the equipment is high.
[0039]
FIG. 4 is a diagram showing an exhaust device for a diesel engine according to a fourth embodiment of the present invention. As shown in the figure, in the present exhaust system, an exhaust silencer 9 is connected to an exhaust pipe 2 connected to an exhaust port of a diesel engine 1, and an exhaust pipe 6 is further connected to the exhaust silencer 9. An unburned gas separation filter 20 is attached in the middle of the exhaust pipe 2. The unburned gas separation filter 20 operates according to the output of the unburned gas detection means 30, that is, the detection result. The unburned gas detection means 30 is configured to detect the unburned gas in the exhaust gas by measuring the temperature of the exhaust gas, and rotates the unburned gas separation filter 20 according to the detection result. The position is switched.
[0040]
FIG. 5 is a view in the direction of arrow A in FIG. 4 showing the configuration of the unburned gas separation filter 20, and the unburned gas separation filter 20 is rotatably mounted around a rotating shaft 23 attached to the center of a circular main body. The combustion gas filter 21 and the unburned gas filter 22 are alternately attached around the rotary shaft 23. By rotating the unburned gas separation filter 20 around the rotating shaft 23, the filter passing through the exhaust pipe 2 is changed from the unburned gas filter 22 to the burned gas filter 21 and from the burned gas filter 21 to the unburned gas. It can be easily switched to the filter 22.
[0041]
As the unburned gas separation filter 20, a filter provided with a filter that cannot permeate unburned gas and is permeable to only burned gas is used by utilizing the difference in permeability between the burned gas and unburned gas. Alternatively, instead of the unburned gas separation filter 20, a separation device capable of adhering only unburned gas is used by utilizing the fact that the gas components of the burned gas and unburned gas are different. According to this separation device, the combustion gas can pass as it is without adhering.
[0042]
When complete combustion is performed at the time of starting the diesel engine 1, the combustion gas flowing inside the exhaust pipe 2 becomes high temperature, so that it is determined by the unburned gas detection means 30 that no unburned gas exists, and the combustion gas is used. A filter 21 is disposed inside the exhaust pipe 2. On the other hand, when unburned gas is generated due to combustion failure or the like when starting the diesel engine, the generated unburned gas flows in the exhaust pipe 2, and the temperature of the unburned gas is compared with the temperature of the combustion gas. Since the temperature is low, the unburned gas detection means 30 determines that there is unburned gas, and the unburned gas filter 22 is arranged inside the exhaust pipe 2. As a result, unburned gas, unburned fuel, and the like that cause detonation in the exhaust gas are separated and removed, and only the combustion gas is guided to the exhaust silencer 9 and discharged from the exhaust pipe 6.
[0043]
A plurality of the unburned gas filter 22 and the burned gas filter 21 are attached, and those other than those disposed in the exhaust pipe 2 can be replaced or cleaned. 20 maintenance can be performed easily.
[0044]
Further, the unburned gas detection means is not limited to the above-described method by detecting the temperature of the exhaust gas, and the diesel engine 1 (not shown) attached to the diesel engine 1 is attached as in the first embodiment. An unburned gas detection means for judging from the operating state of the diesel engine 1 with a specified speed detector that detects the rotational speed after a certain time from the start is also possible.
[0045]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Is possible. It should be noted that any shape or structure not directly described in the specification and drawings is within the scope of the technical idea of the present invention as long as the effects and advantages of the present invention are exhibited.
[0046]
【The invention's effect】
As described above, according to the invention described in each claim, the following excellent effects are obtained.
[0047]
According to the first aspect of the present invention, the temperature of the unburned gas in the exhaust gas can be lowered, and the sparks in the exhaust gas can be shut off. Can be prevented.
[0048]
According to the second aspect of the present invention, since the bypass pipe is provided and the on / off gate valve is attached in the middle of the bypass pipe, when unburned gas is generated from the diesel engine, the exhaust gas is liquefied. Guided to the tank, shuts off the sparks that cause detonation, and can prevent detonation by lowering the temperature of exhaust gas containing unburned gas, and if no unburned gas is generated, The exhaust gas is discharged without passing through the liquid in the liquid tank, and the diesel engine can be operated without applying an extra load.
[0049]
According to the invention described in claim 3, since the bypass pipe is provided, the three-way switching valve is attached to the branch part, and the check valve is attached between the water tank and the junction part, unburned gas is generated from the diesel engine. In this case, the exhaust gas is guided to the liquid tank, and the sparks that cause detonation are shut off, and the temperature of the exhaust gas containing unburned gas can be lowered to prevent detonation. When no gas is generated, the exhaust gas is discharged without passing through the liquid in the liquid tank, and the diesel engine can be operated without applying an extra load.
[0050]
According to the invention of claim 4, since the unburned gas detection means is provided, and when the unburned gas detection means detects the unburned gas, the open / close gate valve is closed or the three-way switching valve is switched to the liquid tank side. Depending on the generation of unburned gas, it is possible to switch the exhaust gas passage. If unburned gas is generated, it will shut off the sparks that cause detonation and remove the unburned gas. Detonation can be prevented by lowering the temperature of the exhaust gas contained, and if unburned gas is not generated, exhaust gas is exhausted without passing through the liquid in the liquid tank to the diesel engine. It becomes possible to operate without applying an extra load.
[0051]
According to the fifth aspect of the present invention, since the liquid tank and the exhaust silencer have an integrated structure, the bypass pipe is eliminated, and the entire exhaust device can be configured compactly.
[0052]
According to the invention described in claim 6, by providing the unburned gas separation means, it is possible to separate and remove the unburned gas in the exhaust gas, and the unburned gas is not led to the exhaust silencer. .
[0053]
According to the seventh aspect of the present invention, the unburned gas separation means includes an unburned gas filter or a combustion gas filter in the exhaust pipe depending on whether the unburned gas in the exhaust gas is greater than or equal to a predetermined allowable value. Therefore, when the unburned gas in the exhaust gas exceeds a predetermined allowable value, the unburned gas is not led to the exhaust silencer.
[Brief description of the drawings]
FIG. 1 is a diagram showing a first embodiment of an exhaust device for a diesel engine according to the present invention.
FIG. 2 is a diagram showing a second embodiment of an exhaust device for a diesel engine according to the present invention.
FIG. 3 is a diagram showing a third embodiment of an exhaust system for a diesel engine according to the present invention.
FIG. 4 is a diagram showing a fourth embodiment of an exhaust device for a diesel engine according to the present invention.
5 is a view showing an unburned gas separation filter 20, and is a view taken in the direction of arrow A in FIG.
[Explanation of symbols]
1 Diesel engine
2 Exhaust pipe
3 Exhaust pipe (inflow pipe)
4 Bypass pipe
5 Exhaust pipe (outflow pipe)
6 Exhaust pipe
7 Aquarium
8 Gate valve
9 Exhaust silencer
10 water
11 Check valve
12 Three-way selector valve
13 Scavenging valve
15 Partition plate
20 Unburned gas separation filter
21 Combustion gas filter
22 Filter for unburned gas
23 Rotating shaft
30 Unburned gas detection means

Claims (7)

In the exhaust system of a diesel engine that leads exhaust gas discharged from a diesel engine to an exhaust silencer through an exhaust pipe,
An exhaust system for a diesel engine, wherein a liquid tank containing a liquid is attached to the exhaust pipe so that exhaust gas discharged from the diesel engine passes through the liquid contained in the liquid tank. The exhaust system for a diesel engine according to claim 1,
The exhaust pipe is provided with a bypass pipe that branches from a branch section provided upstream from the liquid tank and joins at a junction provided downstream from the liquid tank, and an open / close gate valve is attached in the middle of the bypass pipe An exhaust system for a diesel engine characterized by that. The exhaust system for a diesel engine according to claim 1,
The exhaust pipe is provided with a bypass pipe that branches from a branch portion provided upstream from the liquid tank and joins at a junction provided downstream from the liquid tank.
An exhaust system for a diesel engine, wherein a three-way switching valve is attached to the branch part of the exhaust pipe, and a check valve is attached between the liquid tank and the junction part. The exhaust system for a diesel engine according to claim 2 or 3,
An unburned gas detection means for detecting unburned gas in the exhaust gas discharged from the diesel engine is provided,
An exhaust system for a diesel engine, wherein when the unburned gas detection means detects unburned gas, the open / close gate valve is closed or the three-way switching valve is switched to the liquid tank side. The exhaust system for a diesel engine according to claim 1,
An exhaust system for a diesel engine, wherein the liquid tank is attached to a rear end portion of the exhaust pipe and is configured integrally with the exhaust silencer. In the exhaust system of a diesel engine that leads exhaust gas discharged from a diesel engine to an exhaust silencer through an exhaust pipe,
An exhaust system for a diesel engine, wherein the exhaust pipe is provided with unburned gas separation means for separating unburned gas in the exhaust gas. The exhaust system for a diesel engine according to claim 6,
The unburned gas separation means includes an unburned gas filter and a combustion gas filter. When the unburned gas in the exhaust gas is equal to or greater than a predetermined allowable value, the unburned gas filter is placed in the exhaust pipe. An exhaust system for a diesel engine, wherein the exhaust gas filter is arranged so that the combustion gas filter is arranged in the exhaust pipe when the unburned gas in the exhaust gas is below a predetermined allowable value.

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