JP7357331B2 - Scrubber equipment and ships equipped with scrubber equipment - Google Patents

Description

The present invention relates to a scrubber device for treating exhaust gas from a combustion engine, and a ship equipped with the scrubber device.

The scrubber device removes SOx (sulfur oxides) from exhaust gas. Further, scrubber devices are known as a technology that has the potential to not only reduce SOx but also remove black carbon.
Figure 22 is a chronology of tightening regulations regarding the upper limit of the sulfur content concentration of fuel oil. In the ship-related field, many ships are expected to use low-sulfur fuel or be equipped with scrubber devices in line with the 2020 fuel oil sulfur content regulations (SOx regulations).

FIG. 23 is a diagram showing an example of a conventional scrubber device type, and FIG. 23(a) is a packed column type, and FIG. 23(b) is a counterflow type.
In the case of a packed tower type, the packing material may become clogged. Further, liquid ejecting means are required in a plurality of routes, and miniaturization is difficult because a large amount of liquid is flowed. In the case of a counterflow type, it is possible to downsize the combustion engine, but the pressure loss is large and there is a risk that reverse pressure will be applied to the combustion engine.

Here, in Patent Document 1, when removing harmful components in the exhaust gas to be treated using a scrubber that brings the exhaust gas to be treated and salt water into gas-liquid contact, there are two sides: an upstream side and a downstream side with respect to the flow direction of the salt water in the scrubber. DC voltage is applied through at least one pair of electrodes between the electrodes, and conduction is established between both electrodes via salt water flowing from the upstream side to the downstream side, so that the exhaust gas to be treated and the salt water flowing inside the scrubber and on the surface of the electrodes are connected. An exhaust gas purification method is disclosed in which gas-liquid contact treatment and electrolytic oxidation/reduction treatment are performed.
Further, Patent Document 2 discloses a method for sterilizing underwater marine life for seawater utilization equipment that generates acidic waste liquid, which includes a gas diffusion electrode as a means for generating acidic waste liquid by subjecting combustion exhaust gas to a gas-liquid contact reaction with seawater. It has been disclosed that a combustion exhaust gas purification treatment device consisting of a scrubber having a gas-liquid contact part is used to perform exhaust gas purification treatment by supplying seawater and combustion exhaust gas to the gas-liquid contact part to cause a gas-liquid contact reaction.

Japanese Patent Application Publication No. 2004-89770 Japanese Patent Application Publication No. 2009-112996

Patent Document 1 and Patent Document 2 have complicated device configurations, similar to the packed column type, and are difficult to downsize.
SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a scrubber device that has sufficient ability to treat exhaust gas from a combustion engine and is small in size, and a ship equipped with the scrubber device.

A scrubber device according to claim 1 is a scrubber device for treating exhaust gas from a combustion engine, wherein the scrubber device includes a first exhaust gas path through which the exhaust gas flows, and a treatment liquid for the exhaust gas in the first exhaust gas path. a second exhaust gas path connected to the first exhaust gas path; and a liquid recovery device provided at a connection between the first exhaust gas path and the second exhaust gas path to recover the liquid ; and a liquid flow rate changing means for changing the flow rate of the liquid injected from the liquid injection means according to the load of the combustion engine. The liquid is injected only into the first exhaust gas path , and the liquid flow rate changing means changes the flow rate by selecting a plurality of liquid injection means to be used depending on the load of the combustion engine.
According to the present invention as set forth in claim 1, since the liquid recovery means is provided at the connection between the first exhaust gas path and the second exhaust gas path, the injected liquid can be easily recovered, and the liquid for treatment can be combined with the flow of the exhaust gas. Since the fuel is injected in parallel, there is no back pressure applied to the combustion engine that will impede combustion, and a small scrubber device with high exhaust gas processing capacity can be achieved. Further, by injecting the processing liquid only in the first exhaust gas path, the amount of liquid to be injected can be reduced, and the scrubber device can also be simplified. Furthermore, it is possible to ensure an appropriate amount of liquid depending on the load and to more appropriately process exhaust gas.

The present invention according to claim 2 is characterized in that the liquid/gas ratio, which is the ratio between the flow rate of the liquid injected from the liquid injection means and the flow rate of the exhaust gas flowing through the first exhaust gas path, is set to 4 L/Nm ³ or more.
According to the second aspect of the present invention, the liquid/gas ratio can be ensured and the regulation value for exhaust gas treatment can be more reliably cleared.

A third aspect of the present invention is characterized in that the liquid flow rate changing means changes the flow rate of the liquid injected from the liquid injection means in accordance with the flow rate of the exhaust gas which changes depending on the load of the combustion engine .
According to the third aspect of the present invention, an appropriate liquid/gas ratio can be maintained and exhaust gas can be treated more appropriately .

The present invention as set forth in claim 4 is characterized in that the liquid flow rate changing means changes the flow rate by selecting a combination of a plurality of liquid ejecting means to be used .
According to the fourth aspect of the present invention, the flow rate of the liquid can be changed more easily and appropriately by selecting a combination of liquid ejecting means.

In the present invention as set forth in claim 5 , a plurality of stages of liquid injection means are provided in the first exhaust gas path, and the injection pressure of the liquid injected from the liquid injection means located upstream of the plurality of stages of liquid injection means is directed to the downstream side. It is characterized in that the injection pressure is lower than the injection pressure of the liquid injected from the liquid injection means located therein.
According to the present invention as set forth in claim 5 , it is possible to reduce the amount of liquid to be injected while maintaining a high exhaust gas treatment capacity, thereby saving energy consumption.

A sixth aspect of the present invention is characterized in that the liquid injection means injects the liquid from a position above the center point of the inner diameter of the first exhaust gas path.
According to the present invention as set forth in claim 6 , the injected liquid is less likely to come into contact with the lower wall surface of the first exhaust gas path, and is distributed throughout the entire exhaust gas, making it possible to improve the exhaust gas treatment performance with a smaller flow rate.

The present invention as set forth in claim 7 is characterized in that the first exhaust gas path is directed downward and the second exhaust gas path is directed upward.
According to the seventh aspect of the present invention, the liquid in the liquid recovery means can be easily recovered while preventing the liquid from flowing back toward the liquid injection means.

The present invention as set forth in claim 8 is characterized in that the second exhaust gas path is provided in a substantially vertical direction, and the first exhaust gas path is diagonally connected to the second exhaust gas path.
According to the eighth aspect of the present invention, it is possible to more effectively process the exhaust gas and prevent backflow of the liquid in the liquid recovery means even if the scrubber device is shaken, for example.

The present invention as set forth in claim 9 is characterized in that the liquid recovery means includes a gas-liquid separator that captures the liquid injected into the first exhaust gas path and separates it from the exhaust gas.
According to the present invention as set forth in claim 9 , the injected liquid can be effectively recovered.

The present invention as set forth in claim 10 is characterized in that the second exhaust gas path is provided with a mist catcher for collecting droplets of liquid that cannot be collected by the liquid collecting means.
According to the tenth aspect of the present invention, it is possible to prevent droplets such as the mist of the liquid that cannot be completely recovered by the liquid recovery means and the mist generated by the injected liquid from being discharged to the outside of the scrubber device.

The present invention according to claim 11 is characterized in that sulfur oxides contained in exhaust gas from a combustion engine are treated.
According to the eleventh aspect of the present invention, it is possible to reduce SOx (sulfur oxides) contained in exhaust gas.

The present invention according to claim 12 is characterized in that seawater is used as the liquid.
According to the present invention as set forth in claim 12 , the desulfurization performance can be improved compared to the case of fresh water or industrial water, and it can be provided at a low cost.

A ship equipped with a scrubber device according to claim 13 is characterized in that the scrubber device is installed on the ship to treat exhaust gas from a diesel engine serving as a combustion engine.
According to the present invention as set forth in claim 13 , it is possible to make ships comply with fuel oil sulfur concentration regulations (SOx regulations), exhaust gas regulations, etc., and for example, it is also possible to remove black carbon.

The present invention as set forth in claim 14 is characterized in that the operation of the scrubber device is controlled in accordance with exhaust gas regulations from ships that differ depending on the sea area.
According to the fourteenth aspect of the present invention, it is possible to efficiently operate the scrubber device in accordance with exhaust gas regulations for each sea area.

According to the scrubber device of the present invention, since the liquid recovery means is provided at the connection between the first exhaust gas path and the second exhaust gas path, the injected liquid can be easily recovered, and the treatment liquid is injected in parallel with the flow of the exhaust gas. Therefore, it is possible to provide a small-sized scrubber device that has high exhaust gas processing ability without adverse pressure being applied to the combustion engine and causing combustion problems. Further, by injecting the processing liquid only in the first exhaust gas path, the amount of liquid to be injected can be reduced, and the scrubber device can also be simplified. Furthermore, it is possible to ensure an appropriate amount of liquid depending on the load and to more appropriately process exhaust gas.

In addition, when the liquid/gas ratio, which is the ratio of the flow rate of the liquid injected from the liquid injection means to the flow rate of the exhaust gas flowing through the first exhaust gas path, is set to 4 L/Nm ³ or more, the liquid/gas ratio is secured and the exhaust gas Processing regulation values can be more reliably cleared.

In addition, when changing the flow rate of the liquid injected from the liquid injection means in accordance with the flow rate of exhaust gas that changes depending on the load of the combustion engine , the liquid flow rate changing means maintains an appropriate liquid/gas ratio and Exhaust gas can be appropriately treated .

In addition , the liquid flow rate changing means can be changed by selecting a combination of a plurality of liquid ejecting means to be used. Flow rate can be changed.

Further, a plurality of stages of liquid injection means are provided in the first exhaust gas path, and the injection pressure of the liquid to be injected from the liquid injection means located on the upstream side of the plurality of stages of liquid injection means is injected from the liquid injection means located on the downstream side. When the injection pressure is lower than the liquid injection pressure, the amount of liquid injection can be kept low while maintaining a high exhaust gas treatment capacity, and energy consumption can be saved.

Furthermore, when the liquid injection means injects the liquid from a position above the center point of the inner diameter of the first exhaust gas path, the injected liquid becomes difficult to come into contact with the lower wall surface of the first exhaust gas path, and the liquid is distributed throughout the entire exhaust gas. Exhaust gas treatment performance can be improved with a smaller flow rate.

In addition, when the first exhaust gas path is configured to face downward and the second exhaust gas path is directed upward, the liquid in the liquid recovery means can be prevented from flowing back toward the liquid injection means, and the liquid in the liquid recovery means can be Liquid recovery can be facilitated.

In addition, when the second exhaust gas path is provided in a substantially vertical direction and the first exhaust gas path is connected to the second exhaust gas path diagonally, the exhaust gas can be processed more effectively and, for example, the scrubber device can be oscillated. It is possible to prevent backflow of the liquid in the liquid recovery means even if the liquid is recovered.

Furthermore, when the liquid recovery means includes a gas-liquid separator that captures the liquid injected into the first exhaust gas path and separates it from the exhaust gas, the injected liquid can be effectively recovered.

In addition, if the second exhaust gas path is equipped with a mist catcher that collects droplets of liquid that could not be recovered by the liquid recovery means, the mist of the liquid that could not be recovered by the liquid recovery means or the sprayed liquid may It is possible to prevent the generated mist and other droplets from being discharged to the outside of the scrubber device.

Furthermore, when treating sulfur oxides contained in exhaust gas from a combustion engine, it is possible to reduce SOx (sulfur oxides) contained in exhaust gas.

Furthermore, when seawater is used as the liquid, it has higher desulfurization performance and can be provided at a lower cost than in the case of fresh water or industrial water.

Further, according to a ship equipped with the scrubber device of the present invention, the ship can be made to comply with fuel oil sulfur concentration regulations (SOx regulations), exhaust gas regulations, etc., and, for example, black carbon can be removed.

Furthermore, when the operation of the scrubber device is controlled in accordance with exhaust gas regulations from ships that differ for each sea area, the scrubber device can be operated efficiently in accordance with the exhaust gas regulations for each sea area.

Installation schematic diagram of a scrubber device according to an embodiment of the present invention A schematic diagram of the main parts of the scrubber device Exterior photo of the liquid injection means Schematic diagram of a scrubber device according to another embodiment A schematic diagram of a scrubber device according to still another embodiment A schematic diagram of a scrubber device according to still another embodiment Configuration diagram of test equipment Exterior photo of part of the scrubber device in the test equipment Graph showing estimated flow rate versus liquid pressure for each injection nozzle Graph showing the measurement results of black carbon by a scrubber device using two liquid injection means having injection nozzles with the same diameter Graph showing test results of black carbon reduction rate by scrubber device using three liquid injection means having injection nozzles with different diameters (load rate 37.5%) Graph showing evaluation results of desulfurization performance by a scrubber device using two liquid injection means having injection nozzles of the same diameter (load rate 50%) Graph showing the test results of exhaust gas properties when changing the exhaust gas measurement position in a scrubber device using two liquid injection means having injection nozzles with the same diameter Graph showing test results of exhaust gas properties when changing liquid properties in a scrubber device using two liquid injection means having injection nozzles with the same diameter (load rate 50%, measurement position 0.9 m) Graph showing test results regarding the effect of liquid water flow rate on desulfurization performance in a scrubber device using two liquid injection means having injection nozzles with the same diameter (load rate 25 to 100%) Graph showing the results of measuring exhaust gas properties by changing the injection nozzle and liquid flow rate in a scrubber device using three liquid injection means having injection nozzles with different diameters. A graph showing the desulfurization performance versus liquid flow rate at each engine load factor, which is a compilation of the graphs in Figure 16. A graph showing the desulfurization performance versus liquid flow rate at each engine load factor, with the horizontal axis of the graph in Figure 17 as the liquid/gas ratio. Graph showing test results regarding the influence of injection nozzles on desulfurization performance in a scrubber device using two liquid injection means having injection nozzles of the same diameter Graph showing test results regarding the influence of exhaust gas flow rate (load factor) in a scrubber device using two liquid injection means having injection nozzles of the same diameter Graph showing test results regarding the influence of exhaust gas flow rate (load factor) in a scrubber device using two liquid injection means having injection nozzles of the same diameter Chronology of strengthening regulations regarding the upper limit of sulfur content in fuel oil Diagram showing an example of a conventional scrubber device model

Below, a scrubber device according to an embodiment of the present invention and a ship equipped with the scrubber device will be described.

FIG. 1 is an installation schematic diagram of a scrubber device according to this embodiment.
Exhaust gas from a combustion engine 100 such as a diesel engine flows into the scrubber device 1 through a selective catalytic reduction and denitration device (SCR) 200 or by bypassing the selective catalytic reduction and denitration device (SCR) 200.

FIG. 2 is a schematic view of the main parts of the scrubber device according to this embodiment, with FIG. 2(a) being an overall view and FIG. 2(b) being a diagram of a liquid ejecting means. Moreover, FIG. 3 is an external photograph of the liquid ejecting means.
The scrubber device 1 processes exhaust gas from the combustion engine 100. In FIG. 2, the flow direction of exhaust gas is indicated by an arrow. The scrubber device 1 includes a first exhaust gas path 10 through which exhaust gas flows, a liquid injection means 20 that injects a treatment liquid to the exhaust gas in the first exhaust gas path 10 in parallel with the flow of the exhaust gas, and is connected to the first exhaust gas path. The second exhaust gas path 30 is provided with a second exhaust gas path 30 , and a liquid recovery means 40 is provided at a connecting portion between the first exhaust gas path 10 and the second exhaust gas path 30 to recover the liquid. In the scrubber device 1, the liquid for exhaust gas treatment is injected only into the first exhaust gas path 10.
Since the liquid recovery means 40 is provided at the connection between the first exhaust gas path 10 and the second exhaust gas path 30, the injected liquid can be easily recovered. The scrubber device 1 can be small-sized and has a high exhaust gas processing ability without causing a problem in combustion due to back pressure being applied to the scrubber device 1.
Further, by injecting the liquid for exhaust gas treatment only in the first exhaust gas path 10 in parallel with the flow of the exhaust gas, the amount of liquid to be injected can be reduced, and the scrubber device 1 can be simplified.
Further, the scrubber device 1 can reduce SOx (sulfur oxides) contained in the exhaust gas from the combustion engine 100.

A plurality of liquid injection means 20 are provided, each of which is provided with an injection nozzle. The diameter of the injection nozzle of the first liquid injection means 20A is larger than the diameter of the injection nozzle of the second liquid injection means 20B, and the diameter of the injection nozzle of the second liquid injection means 20B is larger than the diameter of the injection nozzle of the second liquid injection means 20C. larger than the diameter of the injection nozzle. The aperture ratio of the injection nozzles is: first liquid injection means 20A: second liquid injection means 20B: third liquid injection means 20C≈4:2:1. Thereby, the flow rate [L/min] of the liquid injected from each injection nozzle is made different.
As shown in FIG. 2, the injection port of the injection nozzle of the first liquid injection means 20A is arranged at a position above the center point C of the inner diameter of the first exhaust gas path 10, and the injection port of the second liquid injection means 20B is The injection port of the nozzle is arranged at the center point C of the inner diameter of the first exhaust gas path 10, and the injection port of the injection nozzle of the third liquid injection means 20C is arranged below the center point C of the inner diameter of the first exhaust gas path 10. placed in position. By injecting the liquid from a position above the center point C of the inner diameter of the first exhaust gas path 10, the injected liquid injects the liquid from a position below the center point C of the inner diameter of the first exhaust gas path 10. Compared to the case, it is less likely to come into contact with the lower wall surface of the first exhaust gas path 10, and the exhaust gas can be distributed throughout the entire exhaust gas, thereby improving exhaust gas treatment performance with a smaller flow rate.

The liquid ejecting means 20 includes a liquid flow rate changing means 50 that changes the flow rate of the liquid injected from the liquid ejecting means 20 according to the flow rate of the exhaust gas. The liquid flow rate changing means 50 is composed of a valve and a control section, and controls the flow rate of the liquid to be injected according to the separately measured exhaust gas flow rate.
By changing the flow rate of the injected liquid according to the flow rate of the exhaust gas, an appropriate liquid/gas ratio can be maintained and the exhaust gas can be treated more appropriately.
Further, the liquid flow rate changing means 50 can also change the flow rate of the injected liquid depending on the load of the combustion engine 100. The load on the combustion engine 100 is determined from sensor information such as a rotation detector. Thereby, an appropriate amount of liquid can be secured according to the load, and exhaust gas can be treated more appropriately.
Further, when a plurality of liquid ejecting means 20 are provided as in this embodiment, the liquid flow rate changing means 50 can change the flow rate of the liquid by selecting the number of liquid ejecting means 20 to be used. can. Thereby, the number of liquid ejecting means 20 to be used can be selected and the flow rate of the liquid can be changed more easily and appropriately.

In the scrubber device 1, the first exhaust gas path 10 is configured to face downward, and the second exhaust gas path 30 is configured to face upward. Thereby, exhaust gas can be effectively treated. Further, the connecting portion between the first exhaust gas path 10 and the second exhaust gas path 30 is located below the liquid injection means 20 disposed on the exhaust gas inlet side to the first exhaust gas path 10. The liquid collected in the provided liquid recovery means 40 can be prevented from flowing back toward the liquid injection means 20, and the liquid can be easily recovered in the liquid recovery means 40. This is particularly effective when the scrubber device 1 is applied to a ship whose hull is moving.
Furthermore, the second exhaust gas path 30 is provided so as to stand up in a substantially vertical direction, and the first exhaust gas path 10 is diagonally connected to the second exhaust gas path 30. This makes it possible to more effectively process the exhaust gas and prevent backflow of the liquid in the liquid recovery means 40 even if the scrubber device 1 swings, for example.
In FIG. 2, the first exhaust gas path 10 is connected diagonally to the second exhaust gas path 30 at an angle of about 45 degrees; however, when applied to a ship, it is connected to the second exhaust gas path 30 at an angle of about 45 degrees. It is desirable that the angle is .

The liquid recovery means 40 has a structure including a gas-liquid separator 41 that captures the liquid injected into the first exhaust gas path 10 and separates it from the exhaust gas. Thereby, the injected liquid can be effectively recovered.
In this embodiment, the connecting portion between the first exhaust gas path 10 and the second exhaust gas path 30 is provided a predetermined distance above the bottom surface of the device, so that a gas-liquid separator 41 is provided between the connecting portion and the bottom surface of the device. The liquid accumulated in the gas-liquid separator 41 is sent to a drain tank (not shown) via a drain pipe 42 connected to the bottom surface of the device.

Further, the scrubber device 1 includes a mist catcher 60 above the second exhaust gas path 30 for collecting droplets of liquid that could not be collected by the liquid collection means 40. Thereby, it is possible to prevent droplets such as the mist of the liquid that cannot be completely recovered by the liquid recovery means 40 and the mist generated by the injected liquid from being discharged to the outside of the scrubber device 1 . Note that the liquid droplets that could not be recovered by the liquid recovery means 40 contain sulfuric acid mist generated due to rapid cooling of the exhaust gas, and depending on the scrubber device 1, the sulfuric acid mist may account for most of the sulfuric acid mist. Sometimes it occupies.

Further, the scrubber device 1 can also use seawater as the liquid. By using seawater as the liquid for exhaust gas treatment, desulfurization performance can be improved compared to fresh water or industrial water, and it can be provided at a lower cost.

In addition, by installing the scrubber device 1 on a ship and treating exhaust gas from a diesel engine as the combustion engine 100, the ship can be made to comply with fuel oil sulfur concentration regulations (SOx regulations), exhaust gas regulations, etc. For example, black carbon can also be removed.
In addition, when the scrubber device 1 is installed on a ship, the operation of the scrubber device 1 can be controlled in accordance with the exhaust gas regulations from ships that differ depending on the sea area. It is possible to carry out effective operations.

Next, a scrubber device according to another embodiment of the present invention and a ship equipped with the scrubber device will be described. In addition, the same reference numerals are attached to the same functional members as in the above-described embodiment, and the description thereof will be omitted.
FIG. 4 is a schematic diagram of a scrubber device according to another embodiment of the present invention.
The scrubber device 1 according to the present embodiment is provided with liquid injection means 20 in two stages, an upstream side and a downstream side, in the first exhaust gas path 10, and the liquid injection means 20 located on the upstream side of the two stages of liquid injection means 20. The injection pressure of the liquid injected from the liquid injection means 20 is set lower than the injection pressure of the liquid injected from the liquid injection means 20 located on the downstream side.
By providing the liquid injection means 20 in multiple stages, exhaust gas can be treated even more effectively. In addition, since the main purpose of the liquid injection from the upstream liquid injection means 20 can be to lower the exhaust gas temperature, the amount of liquid injection can be kept low while maintaining high exhaust gas processing capacity to save energy consumption. be able to.
Note that the liquid ejecting means 20 may be provided in three or more stages.

Next, a scrubber device according to still another embodiment of the present invention and a ship equipped with the scrubber device will be described. In addition, the same reference numerals are attached to the same functional members as in the above-described embodiment, and the description thereof will be omitted.
FIG. 5 is a schematic diagram of a scrubber device according to still another embodiment of the present invention.
In FIG. 5A, the first exhaust gas path 10 is provided perpendicularly to the second exhaust gas path 30. In FIG.
In FIG. 5(b), the first exhaust gas path 10 is provided parallel to the second exhaust gas path 30. In this case, it is possible to further prevent the liquid accumulated in the liquid recovery means 40 provided at the connection portion from flowing back toward the liquid injection means 20 side.

Next, a scrubber device according to still another embodiment of the present invention and a ship equipped with the scrubber device will be described. In addition, the same reference numerals are attached to the same functional members as in the above-described embodiment, and the description thereof will be omitted.
FIG. 6 is a schematic diagram of a scrubber device according to still another embodiment of the present invention.
In this embodiment, the liquid recovery means 40 is provided with a separation section 43 (gas-liquid separator) made of a porous material and arranged opposite to the outlet of the first exhaust gas path 10. Thereby, the liquid injected into the first exhaust gas path 10 can be captured more reliably and separated from the exhaust gas.
In FIG. 6, the first exhaust gas path 10 is connected to the second exhaust gas path 30 at an angle of about 10 degrees. This was determined based on the actual space requirements with other structures on the ship, and if the angle is less than this, liquid may flow backwards when the ship rocks, so the connection angle is 10 It is preferably at least 15 degrees, more preferably at least 15 degrees. However, this is not the case when the first exhaust gas path 10 is provided with a backflow prevention means.

Next, test results using the scrubber device according to the embodiment of the present invention will be explained.
FIG. 7 is a configuration diagram of the test device. Moreover, FIG. 8 is an external photograph of a part of the scrubber device in the test equipment.
The test equipment includes an SO ₂ meter and a CO ₂ meter 71, an exhaust gas outlet temperature meter 72, an exhaust gas path temperature meter 73, an O ₂ meter 74, an exhaust gas inlet temperature meter 75, a booster pump 76, a sample collection port 77, and a circulation tank. 78, a turbidity meter 79, a PAH meter 80, a pH meter 81, a scrubber water temperature meter 82, a pH controller 83, a circulation pump 84, and a circulating water cooler 85.

In this test, heavy oil C (sulfur concentration of about 2.0 to 3.5%) was used. Furthermore, a 257 kW medium-speed diesel engine was used as the combustion engine 100. Table 1 below shows the main features of diesel engines.

The scrubber device 1 used in the test is designed to desulfurize SO ₂ in exhaust gas from a diesel engine, and is capable of processing exhaust gas with an SO ₂ concentration of approximately 800 ppm and a maximum flow rate of approximately 1200 Nm ³ /h. It is.
The scrubber device 1 injects a liquid (cleaning water) for absorbing SO ₂ into the exhaust gas. Note that the second exhaust gas path 30 is provided with a second liquid injection means 86 that injects a processing liquid downward, but it was not used in this test.
When the scrubber device 1 is operated in a closed loop, the injected liquid is stored in the circulating water tank 78 from the lower circulating water outlet, and is again injected into the exhaust gas as a liquid for exhaust gas treatment. In the circulating water tank 78, 25% sodium hydroxide is automatically injected to maintain the pH at 7.
In addition, in the test, C heavy oil with a sulfur content of approximately 2.2% was used as fuel (initially, the sulfur content was 2.24%, and thereafter the sulfur content was 2.16% for refueling).

A liquid ejecting means 20 shown in FIG. 3 was used in the test. As described above, the diameters of the injection nozzles are different in the first liquid injection means 20A, the second liquid injection means 20B, and the third liquid injection means 20C, and these injection nozzles can be used in combination. That is, depending on the liquid flow rate, the state of liquid injection can be changed by using the injection nozzles in any combination. Table 2 below shows the detailed specifications of the three types of injection nozzles. Moreover, FIG. 9 shows estimated values of the flow rate with respect to the liquid pressure of each injection nozzle. In addition, in FIG. 9, the injection nozzle of the first liquid injection means 20A is No. 3. The injection nozzle of the second liquid injection means 20B is No. 2. The injection nozzle of the third liquid injection means 20C is No. Corresponds to 3.

The following tests (I) and (II) were conducted to examine the effects of liquid injection conditions and liquid flow rates on SOx and black carbon processing performance.
(I) Measurement of black carbon by the scrubber device 1 using two liquid injection means 20 having injection nozzles of the same diameter As a preliminary test, two liquid injection means having injection nozzles of the same diameter were used downstream of the mist catcher 60. The black carbon processing capacity of the scrubber device 1 using the scrubber device 20 is measured using an actual device.
(II) Test to investigate the influence of liquid jetting by the scrubber device 1 using three liquid jetting means 20 having jetting nozzles with different diameters Using the liquid jetting means 20 that can change the state of liquid jetting shown in FIG. Then, the black carbon processing capacity is measured by changing the injection nozzle and liquid flow rate. In order to examine the influence of liquid injection, the black carbon measurement position was set to a pipe 0.9 m away from the injection nozzle (see FIG. 8).

In order to verify the black carbon processing ability of the scrubber device 1, a diesel engine was operated with C heavy oil (sulfur content concentration 2.2%), and the scrubber device 1 used two liquid injection means 20 having injection nozzles of the same diameter. The black carbon reduction rate was measured using The black carbon reduction rate was calculated from the BC concentration immediately after the engine (before the scrubber device 1) and the BC concentration sampled in the pipe downstream of the mist catcher 60 (after the scrubber device 1). Figure 10 shows the test results. FIG. 10 is a graph showing the measurement results of black carbon by a scrubber device (packed tower type) using two liquid injection means having injection nozzles of the same diameter.
From this, it can be seen that the black carbon reduction rate is about 60 to 80% in the range of engine load factor of 25 to 100%.

Using a scrubber device 1 that uses three liquid injection means 20 having injection nozzles with different diameters, the black carbon processing capacity was measured while changing the injection nozzles and the liquid flow rate. In order to examine the influence of liquid injection, the black carbon measurement position was set to a pipe 0.9 m away from the injection nozzle (see FIG. 8).

FIG. 11 shows the test results of the black carbon reduction rate when using the scrubber device 1 using three liquid injection means 20 having injection nozzles with different diameters when the engine load factor is 37.5%. From this, it can be seen that the black carbon reduction rate increases as the liquid flow rate increases, and increases as the injection nozzle becomes smaller at the same liquid flow rate. This means that the black carbon reduction ability of the scrubber device 1 is strongly influenced by the injection nozzle, and by using an appropriate injection nozzle suitable for the liquid flow rate, a high black carbon reduction rate can be achieved even with a small amount of liquid. This shows that it is possible to obtain

FIG. 12 is an example of the results of a test conducted separately, and is the result of evaluating desulfurization performance from SO ₂ concentration (ppm) and CO ₂ concentration (% v/v) when the engine load rate is 50%.
This test was conducted using a scrubber device 1 that uses two liquid injection means 20 having injection nozzles of the same diameter, and with two injection nozzles of the same type installed, the injection nozzle used Measurements are made by changing the number of . This shows that the desulfurization performance is strongly influenced not only by the liquid flow rate but also by the liquid injection conditions. Note that the broken line shown in FIG. 12 represents the regulation value (SO ₂ /CO ₂ = 21.7 or less, equivalent to 0.5% S).

The following items were confirmed from these tests.
1) An actual machine test was conducted on the black carbon processing ability of the scrubber device 1 using two liquid injection means 20 having injection nozzles of the same diameter, and the black carbon reduction rate was 60 to 60% in the engine load rate range of 25 to 100%. It was confirmed that it was about 80%.
2) Black carbon processing capacity is strongly affected by liquid injection conditions, and we confirmed that by using an appropriate injection nozzle suited to the liquid flow rate, a high black carbon reduction rate can be obtained even with a small amount of liquid. .
3) It was confirmed that the maximum black carbon reduction rate was about 55% at a position 0.9 m away from the injection nozzle.
From the above, it was confirmed that the scrubber device 1 is effective not only in reducing SOx but also in reducing black carbon.

The results of the above-mentioned confirmation test of the scrubber device 1 using the actual equipment confirmed that it was possible to reduce black carbon by up to 55% in a pipe with a length of about 0.9 m, and also achieved desulfurization performance to clear SOx regulations. It was confirmed that On the other hand, when the scrubber device 1 is mounted on a relatively small ship of several hundred to several thousand tons, the scrubber device 1 needs to be downsized. Therefore, we focused on downsizing the scrubber device 1 assuming that it would be installed on a relatively small ship, and here are the results of a detailed investigation of the desulfurization performance and the results of a trial design of the small scrubber device 1. At the same time, the black carbon reduction effect of the small scrubber device 1 will be evaluated.

A test was conducted to estimate the amount of liquid water (pump specifications including injection pressure) required when installed on an actual ship.
The following actual machine tests (I) to (III) were conducted.
(I) Measurement of exhaust gas properties when changing the exhaust gas measurement position In the scrubber device 1 using two liquid injection means 20 having injection nozzles of the same diameter, the distance from the injection nozzle to the measurement position is 0.3~ The exhaust gas properties are measured when changing over a range of 1.5 m (see Figure 8).
(II) Desulfurization performance when using seawater Measure the exhaust gas properties when using seawater assuming use with an open-loop scrubber. The measurement position of the exhaust gas properties is set at a distance of 0.9 m from the injection nozzle to the measurement position.
(III) Test using scrubber device 1 using three liquid injection means 20 having injection nozzles with different diameters The distance from each injection nozzle of three liquid injection means 20 to the measurement position was 0.9 m, and the engine load factor and The exhaust gas properties are measured by changing the liquid flow rate. Furthermore, a comparison will be made with the test results of the scrubber device 1 using two liquid injection means 20 having injection nozzles of the same diameter.

FIG. 13 shows the desulfurization performance when the distance from the injection nozzle to the measurement position is varied in the range of 0.3 to 1.5 m in the scrubber device 1 using two liquid injection means 20 having injection nozzles of the same diameter. This is the result of finding. In this test, the SO ₂ concentration and CO ₂ concentration in the exhaust gas are measured, and the desulfurization performance is evaluated based on the ratio. From this, the longer the measurement position and the higher the liquid flow rate, the higher the desulfurization performance.When the liquid flow rate is 120L/min, when the distance from the injection nozzle to the measurement position is 0.6m or more, and when the liquid flow rate is 90L/min, It can be seen that the regulation value (SO ₂ /CO ₂ = 21.7 or less, equivalent to 0.5% S) can be cleared when the distance from the injection nozzle to the measurement position is 0.9 m or more. That is, it was possible to set a guideline for the dimensions of the scrubber device 1 and the liquid flow rate in order to clear the regulation values.

When designing equipment with the aim of downsizing the scrubber device 1, an open-loop scrubber that uses seawater as the liquid is promising. This is because open-loop scrubbers can not only reduce the amount of related equipment required, but also have higher desulfurization performance in seawater than in fresh water.
FIG. 14 shows the results of examining the influence of liquid (fresh water, seawater) by varying the liquid flow rate with the engine load factor set at 50%. This shows that seawater has higher desulfurization performance than fresh water.

FIG. 15 shows test results when the engine load factor was set to 25 to 100% in the scrubber device 1 using two liquid injection means 20 having injection nozzles of the same diameter. Desulfurization performance was evaluated from the SO ₂ concentration and CO ₂ concentration measured during this test. The broken line shown in FIG. 15 represents the regulation value (equivalent to 0.5% S when SO ₂ /CO ₂ = 21.7 or less). It can be seen that when the liquid flow rate is 100%, the liquid flow rate is about 130 L/min, which clears the regulation value. This means that the desulfurization performance to clear the regulation value can be obtained in the pipe with a length of about 0.9 m shown in FIG. 8.

FIG. 16 shows the results of measuring exhaust gas properties while changing the injection nozzles and liquid flow rate in the scrubber device 1 using three liquid injection means 20 having injection nozzles with different diameters.
Figure 16(a) shows the results when the engine load factor is 25%, and in the scrubber device 1 using two liquid injection means 20 having injection nozzles of the same diameter, 70L is required to clear the regulation value. /min was required, whereas injection nozzle No. It can be seen that sufficient desulfurization performance is obtained with a liquid flow rate of about 15 L/min by using Nozzle No. 1 (the smallest nozzle).
FIG. 16(b) shows the results when the engine load factor is 50%, and the results are shown for injection nozzle No. 1 or No. 2, sufficient desulfurization performance can be obtained with a liquid flow rate of about 1/3 compared to the liquid flow rate of the scrubber device 1 using two liquid injection means 20 having injection nozzles of the same diameter. I understand.
FIGS. 16(c) and 16(d) show the results when the engine load factor is 75% and 100%, respectively, and the injection nozzle No. 3 (the largest nozzle) or a combination of a plurality of injection nozzles can provide the desulfurization performance to meet the SOx regulations.

From this, it was confirmed that desulfurization performance to meet SOx regulations could be obtained in the engine load ratio range of 25 to 100%. In addition, the desulfurization performance of the scrubber device 1 is strongly influenced by the injection nozzle, and by using an appropriate injection nozzle suitable for the liquid flow rate, the scrubber device 1 uses three liquid injection means 20 having injection nozzles with different diameters. It was confirmed that high desulfurization performance can be obtained even with a small amount of liquid. That is, by attaching an inverter or the like to the electric motor of the liquid injection pump and performing appropriate control, it is possible to reduce the pump power output.

FIG. 17 is a graph arranging the test results shown in FIG. 16, extracting and plotting the results when appropriate injection nozzles were used at each engine load factor. There is a limit on the temperature inside the column of the scrubber device 1, and when the engine load rate is 75%, the injection nozzle No. 1 and no. Since it was not possible to operate with a combination of 2, there is a large difference in liquid flow rate between 50% and 75% engine load rates. It is thought that if the scrubber device 1 has high heat resistance, appropriate desulfurization performance can be obtained with a smaller liquid flow rate even during an engine load rate of 50 to 75%.

FIG. 18 is a graph in which the horizontal axis of FIG. 17 is the liquid/gas ratio (ratio of liquid flow rate [L/h] to exhaust gas flow rate [Nm3/h]). The liquid/gas ratio is an index representing the performance of the scrubber device 1, and is a numerical value that can be used for designing the scrubber device 1, controlling the liquid flow rate, and the like. The test results show that the liquid/gas ratio is 7L/Nm ³ or less, clearing the regulatory value.

The scrubber device 1 prototyped in this test can be approximately 1/2 the height of conventional scrubber devices, achieving significant miniaturization and achieving engine load rates in the range of 25% to 100%. This provides desulfurization performance to meet SOx regulations. Further, the black carbon reduction rate is about 40 to 60%. Furthermore, by using a plurality of liquid injection means 20 each having injection nozzles of different diameters, which were prototyped in this test, the liquid flow rate can be appropriately controlled, so that the pump output can be minimized. This shows that not only can the scope of application of the scrubber device 1 for removing SOx in exhaust gas be expanded to various ships, but also that it can contribute to the reduction of black carbon associated with it.

Further, the scrubber device 1 of this test maintains heat resistance by being made of metal without applying a resin coating for the purpose of preventing material corrosion. Furthermore, by making the scrubber device 1 made of metal, the exhaust gas can be passed through the scrubber device 1 even when liquid is not injected, so the bypass path can be omitted and the device can be further downsized.

FIG. 19 is a diagram showing other results of a test using the scrubber device 1 using two liquid injection means 20 having injection nozzles of the same diameter.
FIG. 19(a) is a diagram showing SO ₂ /CO ₂ versus liquid/gas ratio, and FIG. 19(b) is a diagram showing SO ₂ concentration versus liquid/gas ratio. Note that the broken line shown in FIG. 19(a) indicates the regulation value.
From FIG. 19, it can be seen that appropriate selection of the liquid ejecting means 20 is important for the scrubber device 1.
Also, from FIG. 19(a), although it depends on the sulfur content concentration of the fuel, in order to ensure the liquid/gas ratio and clear the regulation value for exhaust gas treatment, the flow rate of the liquid injected from the liquid injection means 20 must be adjusted. It is preferable that the liquid/gas ratio, which is the ratio of the flow rates of the exhaust gases flowing through the first exhaust gas path 10, is 4 L/Nm ³ or more, and it is more preferable that the liquid/gas ratio is 6 L/Nm ³ or more. In addition, from the viewpoint of saving the amount of liquid to be injected and not increasing the pump capacity, the liquid/gas ratio is preferably 14 L/Nm ³ or less, more preferably 12 L/Nm ³ or less, and even more preferably 10 L/Nm ³ or less. preferable.

FIG. 20 is a diagram showing other results of a test using the scrubber device 1 using two liquid injection means 20 having injection nozzles of the same diameter.
FIG. 20(a) is a diagram showing SO ₂ /CO ₂ versus liquid flow rate depending on engine load factor, and FIG. 20(b) is a diagram showing SO ₂ /CO ₂ versus liquid/gas ratio depending on engine load factor. Note that the broken line shown in FIG. 20 indicates the regulation value.
In FIG. 20, the desulfurization performance was measured while changing the engine load factor in order to examine the influence of the exhaust gas flow rate (flow velocity). It can be seen that even when the load factor is 100%, the regulation value is cleared at a liquid/gas ratio of about 6.7 [L/Nm ³ ].

FIG. 21 is a diagram showing other results of a test using the scrubber device 1 using two liquid injection means 20 having injection nozzles of the same diameter.
Figure 21(a) is a graph showing SO ₂ concentration versus liquid/gas ratio, Figure 21(b) is a graph showing CO ₂ concentration versus liquid/gas ratio, and Figure 21(c) is a graph showing exhaust gas flow rate and temperature versus load factor. FIG.
Based on these data, an appropriate scrubber device 1 can be developed.

INDUSTRIAL APPLICABILITY The present invention can be utilized for exhaust gas treatment in ships and land facilities.

1 Scrubber device 10 First exhaust gas path 20 Liquid injection means 30 Second exhaust gas path 40 Liquid recovery means 41, 43 Gas-liquid separator 50 Liquid flow rate changing means 60 Mist catcher 100 Combustion engine C Center point

Claims (14)

A scrubber device for treating exhaust gas from a combustion engine, comprising a first exhaust gas path through which the exhaust gas flows, and a liquid for injecting a processing liquid to the exhaust gas in the first exhaust gas path in parallel with the flow of the exhaust gas. an injection means, a second exhaust gas passage connected to the first exhaust gas passage, a liquid recovery means for recovering the liquid provided at a connecting portion between the first exhaust gas passage and the second exhaust gas passage , and the liquid injection means. a liquid flow rate changing means for changing the flow rate of the liquid injected from the combustion engine according to the load of the combustion engine, a plurality of the liquid injection means are provided, and the diameters of the respective injection nozzles are different, The liquid is injected only in the first exhaust gas path, and the liquid flow rate changing means performs the change by selecting the plurality of liquid injection means to be used according to the load of the combustion engine. Characteristic scrubber device. 2. The liquid-gas ratio, which is the ratio of the flow rate of the liquid injected from the liquid injection means and the flow rate of the exhaust gas flowing through the first exhaust gas path, is set to 4 L/Nm ³ or more. Scrubber equipment. The liquid flow rate changing means changes the flow rate of the liquid injected from the liquid injection means in accordance with the flow rate of the exhaust gas that changes depending on the load of the combustion engine. The scrubber device according to item 2. 4. The scrubber apparatus according to claim 3 , wherein the liquid flow rate changing means performs the change by selecting a combination of the plurality of liquid ejecting means to be used . A plurality of stages of the liquid injection means are provided in the first exhaust gas path, and the injection pressure of the liquid injected from the liquid injection means located on the upstream side of the plurality of stages of the liquid injection means is controlled by the liquid injection means located on the downstream side. The scrubber device according to any one of claims 1 to 4 , characterized in that the injection pressure of the liquid is lower than the injection pressure of the liquid injected from the liquid injection means. The scrubber device according to any one of claims 1 to 5 , wherein the liquid injection means injects the liquid from a position above a center point of the inner diameter of the first exhaust gas path. The scrubber device according to any one of claims 1 to 6 , wherein the first exhaust gas path is configured to go downward, and the second exhaust gas path is configured to go upward. 8. The scrubber device according to claim 7 , wherein the second exhaust gas path is provided in a substantially vertical direction, and the first exhaust gas path is diagonally connected to the second exhaust gas path. According to any one of claims 1 to 8 , the liquid recovery means includes a gas-liquid separator that captures the liquid injected into the first exhaust gas path and separates it from the exhaust gas. scrubber equipment. The scrubber according to any one of claims 1 to 9 , characterized in that the second exhaust gas path is provided with a mist catcher that collects droplets of the liquid that could not be collected by the liquid collection means. Device. The scrubber device according to any one of claims 1 to 10 , characterized in that the scrubber device treats sulfur oxides contained in the exhaust gas from the combustion engine. The scrubber device according to any one of claims 1 to 11, wherein seawater is used as the liquid. A ship equipped with a scrubber device, characterized in that the scrubber device according to any one of claims 1 to 12 is mounted on the ship, and the exhaust gas from a diesel engine as the combustion engine is processed. 14. A ship equipped with a scrubber device according to claim 13 , wherein the operation of the scrubber device is controlled according to exhaust gas regulations from the ship that differ depending on the sea area.