JP2017056380A - Dry type desulfurization system and exhaust gas treatment equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dry type desulfurization system capable of suitably removing sulfur oxides from an exhaust gas exhausted out of a marine engine, and to provide exhaust gas treatment equipment.SOLUTION: A dry type desulfurization system 40, which removes sulfur oxides from an exhaust gas exhausted out of a diesel engine 11, comprises a dry type desulfurization reactor 41 where a fluid material P1 having a solid particle form and being capable of flowing when the exhaust gas has a predetermined flow rate is stored to make the exhaust gas pass through a fluid part K2 where the fluid material P1 is stored, a desulfurization agent feeder 45 that feeds a desulfurization agent P2 in a solid particle form into the fluid part K2 of the dry type desulfurization reactor 41 where the fluid material P1 is stored, and a classifier 42 arranged on the downstream side from the dry type desulfurization reactor 41 in a flow direction of the exhaust gas to separate the fluid material P1 from the desulfurization agent P2, and to feed the fluid material P1 into the dry type desulfurization reactor 41, thereby exhausting the desulfurization agent P2 and the exhaust gas to the downstream side.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a dry desulfurization system and an exhaust gas treatment apparatus.

  In a marine engine mounted on a marine vessel, a heavy fuel containing a large amount of sulfur is mainly used as a fuel. Exhaust gas discharged from marine engines contains harmful substances such as sulfur oxide (SOx), nitrogen oxide (NOx), and dust. These harmful substances cause air pollution. For this reason, the regulation is strengthened in the ship. A desulfurization system is installed to reduce sulfur oxides in the exhaust gas. As a desulfurization system for marine engines, a wet desulfurization system that performs desulfurization by gas-liquid contact in which a liquid that absorbs sulfur oxides is brought into contact with exhaust gas is known. Moreover, although it is a processing apparatus of the exhaust gas discharged | emitted from a waste combustion furnace instead of a ship, patent document 1 has described the dry-type desulfurization system.

Japanese Patent No. 3009926

  A wet desulfurization system requires wastewater treatment containing sulfur oxides. Moreover, since exhaust gas temperature falls, when performing catalytic denitration in a downstream, a heat exchange apparatus etc. are needed separately. Further, when a dry desulfurization system such as Patent Document 1 is mounted on a ship, further improvement is required in terms of desulfurization performance.

  The present invention has been made in view of the above, and an object of the present invention is to provide a dry desulfurization system and an exhaust gas treatment apparatus that can appropriately remove sulfur oxides from exhaust gas discharged from a marine engine.

  The dry desulfurization system of the present invention for achieving the above object is a dry desulfurization system that removes sulfur oxide from exhaust gas discharged from a marine engine, and is in the form of solid particles, and the exhaust gas has a predetermined flow rate. A dry desulfurization reactor in which the exhaust gas passes through a region where the fluid material is stored, and a region where the fluid material is stored in the dry desulfurization reactor. A desulfurizing agent supply unit for supplying the desulfurizing agent; and a downstream of the dry desulfurization reactor in the exhaust gas flow direction, separating the fluidizing material and the desulfurizing agent; And a classifier for supplying the desulfurization agent and the exhaust gas to the downstream side in the flow direction of the exhaust gas.

  Accordingly, the exhaust gas flowing into the dry desulfurization reactor passes through the region where the fluidized material is stored and contacts the desulfurization agent supplied to the region. Thereby, the sulfur oxide in exhaust gas reacts with a desulfurization agent and is removed. The desulfurizing agent after reacting with the sulfur oxide is flowed to the classifier by the exhaust gas together with the fluidizing material, for example, and discharged to the downstream side together with the exhaust gas by the classifier. In this case, it can suppress that the desulfurization agent after reaction stays in a dry-type desulfurization reactor. Further, by supplying a new desulfurization agent to the dry desulfurization reactor, it is possible to maintain a state in which the unreacted desulfurization agent is disposed in the dry desulfurization reactor. Thereby, sulfur oxides can be appropriately removed from the exhaust gas discharged from the marine engine.

  The dry desulfurization system of the present invention includes a filter that is disposed downstream of the classifier in the flow direction of the exhaust gas and collects the desulfurization agent contained in the exhaust gas via the classifier.

  Therefore, since the desulfurizing agent is recovered from the exhaust gas by the filter, it can be suppressed that the desulfurizing agent is mixed into the exhaust gas and flows to the downstream side.

  The dry desulfurization system of the present invention includes a desulfurization agent recovery unit that recovers the desulfurization agent collected by the filter.

  Therefore, by collecting the desulfurization agent collected by the filter, it is possible to more reliably suppress the desulfurization agent from flowing to the downstream side while the desulfurization agent is mixed in the exhaust gas.

  In the dry desulfurization system of the present invention, the relationship between the average particle size of the fluidizing material and the average particle size of the desulfurizing agent is 15 ≦ (average particle size of the fluidizing material / average particle size of the desulfurizing agent) ≦ 33. Fulfill.

  Therefore, by setting the particle size ratio to 15 or more and 33 or less, it is possible to make the operation under a condition that a fluidized bed is formed during the operation of the ship at a higher time ratio. Moreover, by setting the particle size ratio to 15 or more and 33 or less, it is possible to appropriately form a fluidized bed with an operation load that needs to maintain high desulfurization performance.

  In the dry desulfurization system of the present invention, the desulfurization agent supply unit supplies the desulfurization agent to a pipe through which the fluidized material classified by the classifier is supplied to the dry desulfurization reactor.

  Accordingly, since the desulfurizing agent and the fluidizing material are mixed and supplied to the dry desulfurization reactor, it is possible to prevent the desulfurizing agent or the fluidizing material from being unevenly distributed.

  The dry desulfurization system of the present invention includes a supply amount adjustment unit that adjusts the amount of the desulfurization agent supplied from the desulfurization agent supply unit to the dry desulfurization reactor according to the flow rate of the exhaust gas discharged from the marine engine. .

  Therefore, since the desulfurizing agent can be replenished according to the use situation of the desulfurizing agent, the desulfurizing agent can be used efficiently.

  The dry desulfurization system of the present invention further includes an exhaust gas circulation unit that supplies the exhaust gas that has passed through the classifier to the dry desulfurization reactor.

  Therefore, since the flow rate of the exhaust gas supplied to the dry desulfurization reactor can be adjusted, the fluidized bed can be adjusted to a suitable state.

  An exhaust gas treatment apparatus according to the present invention is provided on the downstream side in the flow direction of the exhaust gas from the dry desulfurization system and the dry desulfurization reactor constituting the dry desulfurization system, and removes nitrogen oxides from the exhaust gas. And a denitration device.

  Therefore, in addition to the effects of the above desulfurization apparatus, the catalyst of the denitration apparatus can be prevented from being deteriorated and the desulfurization performance can be maintained, so that an exhaust gas treatment apparatus with high exhaust gas treatment performance can be obtained.

  According to the present invention, sulfur oxides can be appropriately removed from exhaust gas discharged from a marine engine.

FIG. 1 is a schematic configuration diagram illustrating an exhaust gas treatment apparatus according to the present embodiment. FIG. 2 is a diagram illustrating an example of a dry desulfurization system according to the present embodiment. FIG. 3 is a graph for explaining the flow state of the fluidized material. FIG. 4 is a diagram illustrating a dry desulfurization system according to a modification.

  Hereinafter, embodiments of an exhaust gas treatment apparatus according to the present invention will be described with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

  FIG. 1 is a schematic configuration diagram illustrating an exhaust gas treatment apparatus according to the present embodiment. As shown in FIG. 1, the exhaust gas treatment device 10 includes a dry desulfurization system 40 and a denitration device 47. The exhaust gas treatment device 10 treats exhaust gas discharged from a diesel engine (marine engine) 11 that is mounted on a ship and used as a harmful substance in the exhaust gas, such as sulfur oxide (SOx), nitrogen oxide. (NOx), unburned components, dust, etc. are reduced or removed. In this case, the diesel engine 11 is used as a main engine or a power generation device of a ship.

  The diesel engine 11 is configured such that a scavenging trunk 13 is disposed on one side of a cylinder portion 12 and an exhaust manifold 14 is disposed on the other side. The cylinder portion 12 includes a plurality (six in this embodiment) of cylinders 21 arranged in series. Although not shown, each cylinder 21 is provided with a piston in a reciprocating manner in the vertical direction to form a combustion chamber. Each piston has a lower portion connected to the crankshaft.

  The scavenging trunk 13 is connected to each cylinder 21 of the cylinder portion 12 via an intake port 22. The exhaust manifold 14 is connected to each cylinder 21 of the cylinder portion 12 via an exhaust port 23, and an exhaust valve (not shown) is provided in each exhaust port 23. The scavenging trunk 13 is connected to the intake path L1, and the exhaust manifold 14 is connected to the exhaust path L2. The cylinder portion 12 is provided with an injector 24 for injecting fuel (for example, heavy oil) inside each cylinder 21, and each injector 24 is connected to a fuel tank (not shown).

  Therefore, the cylinder portion 12 is supplied with the fuel supplied from the injectors 24 to the combustion chamber and the combustion gas (for example, air) supplied from the scavenging trunk 13 via the intake ports 22, mixed and compressed. To burn. And each piston moves up and down by the energy generated by this combustion, and the crankshaft to which the lower end of each piston is connected is rotated. On the other hand, the exhaust gas generated by the combustion is discharged to the exhaust manifold 14 through the exhaust port 23.

  The diesel engine 11 is provided with an exhaust turbine supercharger 31. The exhaust turbine supercharger 31 is configured such that a compressor 32 and a turbine 33 are coaxially connected via a rotation shaft 34, and the compressor 32 and the turbine 33 can rotate integrally with the rotation shaft 34. The compressor 32 is connected to an intake path L3 for taking in air or the like from the outside and to an intake path L1 reaching the scavenging trunk 13. The turbine 33 is connected to an exhaust path L2 leading to the exhaust manifold 14, and is connected to an exhaust path L4 for exhausting to the outside. The intake passage L1 is provided with an air cooler 35 that cools the air compressed by the compressor 32.

  Therefore, the turbine 33 is driven by the exhaust gas (combustion gas) guided from the exhaust manifold 14 through the exhaust path L2, and after driving the compressor 32, the exhaust gas is discharged to the outside from the exhaust path L4. On the other hand, the compressor 32 is driven by the turbine 33 and compresses the air taken in from the intake path L3, and then pumps the compressed air from the intake path L1 to the scavenging trunk 13.

  The exhaust path (flow path) L4 discharges exhaust gas discharged from the exhaust manifold 14 and driving the turbine 33 to the outside. The exhaust gas treatment device 10 is provided on the downstream side in the exhaust gas flow direction from the exhaust path L4. As shown in FIG. 1, in the exhaust gas treatment device 10 of the present embodiment, a denitration device 47 is arranged between a classifier 42 and a bag filter 43 described later constituting the dry desulfurization system 40.

  FIG. 2 is a diagram illustrating an example of the dry desulfurization system 40 according to the present embodiment. As shown in FIGS. 1 and 2, a dry desulfurization system 40 includes a desulfurization reactor (dry desulfurization reactor) 41, a classifier 42, a bag filter (filter) 43, a supply pipe (pipe) 44, and a desulfurization. An agent supply unit 45 and a desulfurization agent recovery unit 46 are provided. The dry desulfurization system 40 is provided with a desulfurization reactor 41, a classifier 42, and a bag filter 43 in this order toward the downstream side in the exhaust gas flow direction. In FIG. 2, the denitration device 47 disposed between the classifier 42 and the bag filter 43 is not shown. Here, the dry desulfurization system 40 is a flue gas desulfurization system that supplies a solid (particulate) desulfurization agent into exhaust gas and removes the desulfurization agent by reacting with sulfur oxide in the exhaust gas. Therefore, in the dry desulfurization system 40, water is not used for the reaction of the desulfurization agent, so that wastewater treatment containing sulfur oxide is not necessary. The dry desulfurization system 40 is distinguished from the following wet and semi-dry desulfurization systems. The wet desulfurization system is a flue gas desulfurization system that supplies exhaust gas to an aqueous solution layer or slurry layer in which a desulfurization agent is dissolved or dispersed, and reacts the desulfurization agent with sulfur oxide in the exhaust gas to remove it. Examples of the wet desulfurization system include an apparatus that performs processes such as a lime-gypsum method, a magnesium hydroxide method, and a soda method. The semi-dry type dry desulfurization system is a flue gas desulfurization system in which a slurry obtained by mixing a desulfurization agent and water is sprayed into exhaust gas, and the desulfurization agent is reacted with sulfur oxide to be removed. Examples of the semi-dry type desulfurization system include an apparatus that sprays slaked lime slurry into a spray dryer. The dry desulfurization system 40 is arranged in the order of a desulfurization reactor (dry desulfurization reactor) 41, a classifier 42, and a bag filter (filter) 43 from the upstream side to the downstream side in the exhaust gas flow direction.

  As shown in FIG. 2, the desulfurization reactor 41 includes a casing 51 and a dispersion plate 53. An exhaust gas inlet 52 and an exhaust gas outlet 54 are formed in the casing 51. The casing 51 is formed, for example, in a box shape, and the inside K is hollow. The exhaust gas inlet 52 is provided in the lower part of the housing 51, for example. The exhaust gas inlet 52 is connected to the exhaust path L4. The exhaust gas inlet 52 introduces the exhaust gas flowing through the exhaust path L4 into the interior K of the housing 51. The exhaust gas outlet 54 is provided in the upper part of the housing 51. The exhaust gas outlet 54 is connected to the exhaust path L5.

  The dispersion plate 53 is disposed in the interior K of the casing 51 so as to block the upper side of the exhaust gas inlet 52. By the dispersion plate 53, the interior K is divided into a chamber K1 and a flow part (region) K2. The chamber K1 is formed below the dispersion plate 53. The flow part K2 is formed above the dispersion plate 53. The fluidized part K2 stores a granular material P containing a solid particulate fluidized material P1 and a desulfurizing agent P2.

  The fluidizing material P1 is solid particles and can flow when the exhaust gas has a predetermined flow rate. As the fluid material P1, for example, silica sand, dolomite, limestone, or the like is used. The average particle diameter of the fluidizing material P1 is set so as to form a fluidized bed by the flow of exhaust gas. Here, the average particle diameter is a 50% diameter value measured by a light diffraction scattering method using laser light in accordance with JIS Z 8825 using a particle size distribution measuring device.

  The desulfurizing agent P2 is formed into solid particles so as to flow together with the fluidizing material P1 by the flow of exhaust gas. The desulfurizing agent P2 reacts with the sulfur oxide contained in the exhaust gas, and removes the sulfur oxide from the exhaust gas. As the desulfurizing agent P2, for example, an alkali metal compound or an alkaline earth metal compound is used.

  Further, the dispersion plate 53 is formed in a porous shape so as to allow the exhaust gas to pass therethrough and not allow the particulate matter P to pass therethrough. Therefore, the dispersion plate 53 allows the exhaust gas introduced into the casing 51 from the exhaust gas inlet 52 to pass from the chamber K1 to the fluidizing portion K2 side, and the particulate matter P accommodated in the fluidizing portion K2 falls to the chamber K1 side. It prevents that.

  The classifier 42 is disposed downstream of the desulfurization reactor 41 in the exhaust gas flow direction. The classifier 42 is connected to the desulfurization reactor 41 via the exhaust path L5. The classifier 42 separates the fluidizing material P1 and the desulfurizing agent P2 contained in the exhaust gas. The classifier 42 collects the separated fluid P1 and supplies it to the desulfurization reactor 41, and discharges the desulfurization agent P2 and the exhaust gas downstream. For example, a cyclone is used as the classifier 42. The classifier 42 has an exhaust gas inlet 61, an exhaust gas outlet 62, and a fluidized material recovery unit 63. The exhaust gas inlet 61 is connected to the exhaust path L5 and introduces the exhaust gas from the desulfurization reactor 41. The exhaust gas outlet 62 is provided in the upper part of the classifier 42, and exhausts exhaust gas to the exhaust path L6. The fluid material recovery unit 63 separates the fluid material P1 from the exhaust gas, and discharges the separated fluid material P1 to the supply pipe 44.

  The supply pipe 44 is connected to the classifier 42 and the desulfurizing agent supply unit 45. The supply pipe 44 supplies the fluidized material P1 discharged from the classifier 42 to the desulfurization reactor 41. The supply pipe 44 supplies a desulfurization agent P2 supplied from a desulfurization agent supply unit 45 described later to the desulfurization reactor 41. In the supply pipe 44, the granular material P of the fluidizing material P1 and the desulfurizing agent P2 can be circulated in a fluidized bed state. The supply pipe 44 has a downcomer 44a. The downcomer 44 a is connected to the flow part K <b> 2 of the desulfurization reactor 41. The supply piping 44 supplies the granular material P to the fluidized part K2 via the downcomer 44a. In addition, the fluidized material circulation part R is formed by the exhaust path L5, the exhaust gas inlet 61 and the fluidized material recovery part 63 of the classifier 42, the supply pipe 44 and the downcomer 44a. The fluidizing material circulation portion R is a path for circulating the fluidizing material P1 contained in the exhaust gas discharged from the fluidizing portion K2 to the fluidizing portion K2.

  The desulfurization agent supply unit 45 supplies the desulfurization agent P <b> 2 to the supply pipe 44. The desulfurization agent supply unit 45 includes a supply amount adjustment unit 45a. The supply amount adjusting unit 45 a adjusts the supply amount of the desulfurization agent P <b> 2 according to the flow rate of exhaust gas discharged from the diesel engine 11. In addition, as the value of the flow rate of the exhaust gas, the oxygen concentration of the diesel engine 11 and the amount of fuel supplied to the combustion chamber (engine) are set as in the case of setting the average particle size (Archimedes number) of the fluid P1. The value calculated based on the load) can be used. For example, a flow rate adjustment valve may be provided as the supply amount adjustment unit 45a.

  The bag filter 43 is connected to the classifier 42 via the exhaust path L6, the denitration device 47, and the exhaust path L7. Since the denitration device 47 is disposed between the classifier 42 and the bag filter 43, the dry desulfurization system 40 has the bag filter 43 disposed downstream of the denitration device 47 in the exhaust gas flow direction. For this reason, for example, the bag filter 43 having a heat resistant temperature lower than the exhaust gas temperature required for denitration in the denitration apparatus 47 can be used. For example, when the bag filter 43 having a heat resistance temperature higher than the exhaust gas temperature required for denitration in the denitration device 47 is used, the bag filter 43 is arranged upstream of the denitration device 47 in the exhaust gas flow direction. May be. The bag filter 43 reduces or removes unburned components and dust in the exhaust gas and discharges the exhaust gas to the exhaust path L8. The bag filter 43 has an exhaust gas inlet 71, a filter part 72, and an exhaust gas outlet 73. The exhaust gas inlet 71 is connected to the exhaust path L6 and introduces exhaust gas. The filter unit 72 captures unburned components and dust in the exhaust gas. The filter unit 72 captures the desulfurization agent P2 from the exhaust gas introduced into the bag filter 43. The exhaust gas outlet 73 is connected to the exhaust path L <b> 7 and exhausts the exhaust gas via the filter unit 72.

  Further, the bag filter 43 is provided with a desulfurization agent recovery unit 46. The desulfurization agent recovery unit 46 recovers the desulfurization agent P2 captured by the filter unit 72, for example. The desulfurization agent recovery unit 46 includes a receiving unit 74, a pipe 75, and a tank unit 76. The receiving part 74 receives the desulfurization agent P2 captured and dropped by the filter part 72. The pipe 75 connects the receiving portion 74 and the tank portion 76, and sends the desulfurizing agent P <b> 2 that has dropped to the receiving portion 74 to the tank portion 76. The tank unit 76 stores the desulfurizing agent P2 sent through the pipe 75.

  Further, as shown in FIG. 1, the denitration device 47 is disposed between the classifier 43 and the bag filter 44, and reduces or removes nitrogen oxides in the exhaust gas sent from the exhaust path L6, thereby removing the exhaust gas. Is discharged to the exhaust path L7.

  Further, the exhaust gas treatment device 10 has an exhaust gas recirculation path L9 for returning the exhaust gas to the scavenging trunk 13. The exhaust gas recirculation path L9 connects between the exhaust path L8 and the intake path L3. The exhaust gas recirculation path L9 is provided with a flow rate adjusting valve 49 for adjusting the amount of exhaust gas introduced. The compressor 32 compresses the mixed gas of the air sucked from the intake path L3 and the exhaust gas recirculation gas introduced from the exhaust gas recirculation path L9.

  Next, the operation of the exhaust gas treatment apparatus 10 will be described. As shown in FIG. 1, exhaust gas generated by combustion in the diesel engine 11 is discharged to the exhaust manifold 14 through the exhaust port 23 and is discharged to the exhaust path L2. The exhaust gas is introduced into the exhaust turbine supercharger 31, and after exhausting the turbine 33 and the compressor 32, the exhaust gas is discharged to the exhaust path L4. Further, the air taken into the compressor 32 from the intake path L3 is compressed by the compressor 32 and is pumped to the scavenging trunk 13 from the intake path L1 as combustion gas.

  The exhaust gas discharged to the exhaust path L4 is introduced into the dry desulfurization system 40. Specifically, it is introduced into the chamber K1 from the exhaust gas inlet 52 of the desulfurization reactor 41, and is introduced into the fluidizing section K2 via the dispersion plate 53. The exhaust gas introduced into the fluidized portion K2 flows upward and is discharged from the exhaust gas outlet 54 to the exhaust path L5. The exhaust gas discharged to the exhaust path L5 is discharged to the exhaust path L6 via the classifier 42 and introduced into the bag filter 43. The exhaust gas introduced into the bag filter 43 is removed by the filter unit 72 and is discharged to the exhaust path L7. In this way, the exhaust gas passes through the dry desulfurization system 40.

  At this time, in the desulfurization reactor 41, the flowing material P1 supported by the dispersion plate 53 is fluidized by supplying the exhaust gas. Further, the fluidizing material P1 fluidizes the desulfurizing agent P2 together with the fluidizing material P1. For example, the fluid P1 floats due to the flow of the exhaust gas and is discharged from the exhaust gas outlet 54 to the exhaust path L5 together with the exhaust gas. The fluid material P1 discharged to the exhaust path L5 is separated from the exhaust gas by the classifier 42 and is discharged from the fluid material recovery part 63 to the supply pipe 44. Since the fluidizer P1 is reliably separated from the exhaust gas by the classifier 42, the fluidizer P1 is prevented from flowing to the downstream side while the fluidizer P1 is mixed in the exhaust gas. Then, the fluid P1 is supplied from the supply pipe 44 to the fluid section K2 together with the desulfurizing agent P2 via the downcomer 44a. Since the fluidized material P1 and the desulfurizing agent P2 are mixed and supplied to the fluidizing part K2, the fluidized material P1 or the desulfurizing agent P2 is prevented from being unevenly distributed in the granular material P. Thus, the fluid P1 circulates in the fluid circulation part R from the fluid part K2 to the fluid part K2 via the exhaust path L5, the classifier 42, and the supply pipe 44 (downcomer 44a). Therefore, a circulating fluidized bed S (see FIG. 2) of the fluidized material P1 is formed in the dry desulfurization system 40.

  In the dry desulfurization system 40, the fluidized material P1 and the desulfurizing agent P2 are both floated and flow in the circulating fluidized bed S by the flow of exhaust gas. The desulfurization agent P2 fluidized in the dry reactor 41 contacts the exhaust gas and reacts with the sulfur oxide contained in the exhaust gas. Thereby, the sulfur oxide contained in exhaust gas is removed.

  The dry desulfurization system 40 passes through the dry reactor 41 and the exhaust gas from which the sulfur oxide is removed flows into the classifier 42. Further, in the dry desulfurization system 40, a part of the fluidized material P1 and the desulfurization agent P2 of the dry reactor 41 flows into the classifier 42 together with the exhaust gas. The fluidizing material P1 and the desulfurizing agent P2 flowing into the classifier 42 are separated by the classifier 42 from the exhaust gas. Further, the desulfurizing agent P2 is separated from the exhaust gas in a state where a part of the desulfurizing agent P2 adheres to the fluidizing material P1, and a part of the desulfurizing agent P2 is conveyed to the downstream side together with the exhaust gas. That is, a part of the desulfurizing agent P2 is separated from the fluidized material P1, and is discharged from the exhaust gas outlet 62 to the exhaust gas path L6 together with the exhaust gas, not the circulating path.

  The exhaust gas discharged to the exhaust path L6 is introduced into the denitration device 47 disposed on the downstream side. The denitration device 47 reduces or removes nitrogen oxides contained in the introduced exhaust gas and discharges it to the exhaust path L7. In the dry desulfurization system 40, the exhaust gas flowing into the exhaust passage L7 passes through the bag filter 43. As for the exhaust gas, the foreign matter and the desulfurization agent P2 flowing together with the exhaust gas are collected (captured) by the bag filter 43. In the dry desulfurization system 40, the exhaust gas that has flowed into the exhaust passage L7 after passing through the denitration device 47 passes through the bag filter 43, so even if the heat resistance temperature of the bag filter 43 is lower than the temperature required for denitration in the denitration device 47. Fully usable. The desulfurization agent P <b> 2 captured by the filter unit 72 is collected in the tank unit 76 via the receiving unit 74 and the pipe 75. The dry desulfurization system 40 discharges the exhaust gas that has passed through the bag filter 43 to the exhaust path L8.

  The dry desulfurization system 40 supplies the desulfurization agent P <b> 2 from the desulfurization agent supply unit 45 to the supply pipe 44. As a result, the dry desulfurization system 40 is replenished with the desulfurization agent P2 being discharged from the fluidized portion K2 by the exhaust gas and the number of the desulfurizing agents P2 in the fluidized portion K2 being reduced. Further, the dry desulfurization system 40 adjusts the amount of the desulfurizing agent P2 supplied from the supply amount adjusting unit 45 according to the flow rate of the exhaust gas.

  As described above, in the dry desulfurization system 40 of the present embodiment, the exhaust gas that has flowed into the dry desulfurization reactor 41 passes through the fluidized part K2 in which the fluidized material P1 is stored, and is supplied to the fluidized part K2. Contact P2. Thereby, the sulfur oxide in exhaust gas can react with the desulfurization agent P2, and can be removed. The desulfurization agent P2 after reacting with the sulfur oxide is caused to flow to the classifier 42 by the exhaust gas together with, for example, the fluidizing material P1, and is discharged to the downstream side together with the exhaust gas by the classifier 42. The desulfurizing agent P2 separated from the fluid P1 by the classifier 42 is discharged downstream along with the exhaust gas, so that sulfur oxides in the exhaust gas can be removed while flowing with the exhaust gas. Thereby, the flow path of the exhaust gas that can be desulfurized can be lengthened, and sulfur oxides in the exhaust gas can be suitably removed (reduced). Further, since the desulfurization agent P2 after the reaction can be separated by the classifier 42, it is possible to suppress the desulfurization agent P2 after the reaction from remaining in the dry desulfurization reactor 41.

  In the dry desulfurization system 40, the desulfurization agent P2 captured by the bag filter 43 also reacts with the sulfur oxide in the exhaust gas through which the unreacted component passes. Thereby, the desulfurization agent P2 captured by the bag filter 43 can also remove sulfur oxides in the exhaust gas. Thereby, the flow path of the exhaust gas that can be desulfurized can be made longer, and sulfur oxides in the exhaust gas can be suitably removed (reduced).

  Further, by supplying a new desulfurization agent P2 to the dry desulfurization reactor 41, the state where the unreacted desulfurization agent P1 is disposed in the dry desulfurization reactor 41 can be maintained. As a result, it is possible to improve the desulfurization performance. Moreover, according to this embodiment, since the circulating fluidized bed S is formed in the desulfurization reactor 41 by the flow of exhaust gas, there is no loss of the fluid P1, and the dry desulfurization system 40 with high reactivity is obtained.

  In addition, since the dry desulfurization system 40 according to the present embodiment is a dry dry desulfurization system, there is no need for waste water treatment including, for example, sulfur oxides. Further, since the dry desulfurization system 40 can be discharged to the exhaust path L7 without lowering the temperature of the exhaust gas, it is not necessary to separately provide equipment such as a heat exchanger. Thereby, size reduction and space saving of the dry-type desulfurization system 40 and the exhaust gas treatment apparatus 10 can be achieved.

  Here, fluidization of the fluid P1 in the desulfurization reactor 41 will be described in more detail. When the exhaust gas does not flow, the fluidizing material P1 is in a state of being deposited as a fixed layer on the dispersion plate 53. On the other hand, as the exhaust gas is introduced into the casing 51 and the exhaust gas increases from the dispersion plate 53 to the fluidized portion K2, the fluid P1 starts to flow and forms a fluidized bed. Examples of such a fluidized bed include a bubble fluidized bed and a circulating fluidized bed. The bubble type fluidized bed is a fluidized bed in which bubbles are formed by exhaust gas inside. The circulating fluidized bed is a fluidized bed in which the fluidized material P1 is suspended by the exhaust gas and the suspended fluidized material P1 is circulated by a classifier or the like. When the circulating fluidized bed is formed, the fluidized material P1 needs to be suspended and circulated, so that the fluidity of the fluidized material P1 needs to be higher than that of the bubble fluidized bed. If the fluidity of the fluidizing material P1 is too high, the fluidizing material P1 is scattered with the exhaust gas, and a fluidized bed (circulating fluidized bed) is not formed.

  FIG. 3 is a graph for explaining the flow state of the fluid P1. The horizontal axis of the graph represents Archimedes number (Ar), and the vertical axis of the graph represents Reynolds number (Re). The graph of FIG. 3 is a log-log graph.

  As parameters for determining the flow state of the fluid P1, there are, for example, Archimedes number and Reynolds number which are dimensionless parameters. The Archimedes number is determined by the average particle diameter of the fluidized material P1 in the fluidized bed. The Reynolds number is determined by the flow rate of exhaust gas per unit time supplied to the fluidized bed. The flow rate of the exhaust gas can be calculated based on the oxygen concentration of the diesel engine 11 and the amount of fuel supplied to the combustion chamber (engine load).

  A curve 102 in the graph of FIG. 3 shows the Reynolds number in a state where particles are infinitely linked. The curve 104 in the graph of FIG. 3 shows the Reynolds number on a single particle weekend speed basis. As shown in FIG. 3, when the Archimedes number and Reynolds number of the fluidized material P1 are values within the shaded area 106 surrounded by the curve 102 and the curve 104 of the graph, the fluidized part K2 has a circulating fluidized bed. Can be formed.

  On the other hand, for example, when the Archimedes number is constant, when the Reynolds number is a value above the region 106 (when the gas flow rate per unit time is too large), the fluid P1 is scattered with the exhaust gas. . In addition, when the Reynolds number is a value lower than the region 106 (when the gas flow rate per unit time is too small), a bubble type fluidized bed or a fixed bed is formed.

  For example, when the Reynolds number is constant and the Archimedes number is a value on the left side of the region 106 (when the average particle diameter of the fluid P1 is too small), the fluid P1 is scattered with the exhaust gas. It becomes. When the Archimedes number is a value on the right side of the region 106 (when the average particle diameter of the fluid P1 is too large), a bubble fluidized bed or a fixed bed is formed.

  Thus, when Archimedes number and Reynolds number become the value of the area | region above the area | region 106, it will be in the state which the fluidized material P1 scatters with waste gas. When the Archimedes number and the Reynolds number are values in the lower region of the region 106, a bubble-type fluidized bed or a fixed bed is formed.

  In the present embodiment, the Reynolds number is set according to the load of the diesel engine 11. Therefore, when the circulating fluidized bed is formed using the fluidized material P1, the Archimedes number corresponding to the Reynolds number (load of the diesel engine 11) is set so that the Archimedes number and the Reynolds number of the fluidized material P1 become values in the region 106. What is necessary is just to set (average particle diameter of the fluidized material P1).

  Furthermore, in order to form a circulating fluidized bed in the fluidized part K2 of the casing 51, it is necessary to consider the height of the fluidized part K2. In this case, as the Reynolds number increases, that is, as the flow rate of exhaust gas per unit time increases, it is necessary to increase the height of the casing 51 so that the fluid P1 does not scatter. Since the housing | casing 51 is provided in a ship, it is calculated | required that height does not become high too much. For this reason, when the Reynolds number becomes large, for example, when the value is 15 or more, the Archimedes number (average particle diameter of the fluid P1) is set so that the height of the casing 51 does not become too high. Good. In addition, when fluidizing the fluid P1, the average particle size of the fluid P1 may be reduced due to wear. Therefore, the Archimedes number (average particle diameter of the fluidized material P1) may be set in consideration of the reduction of the particle diameter due to such wear.

  Here, the particle size ratio of the fluidizing material P1 and the desulfurizing agent P2 (average particle size of the fluidizing material P1 / average particle size of the desulfurizing agent P2) can be set to be 15 or more and 33 or less, for example. However, the present invention is not limited to this. By setting the particle size ratio to 15 or more and 33 or less, it is possible to make the operation under a condition that a fluidized bed is formed during the operation of the ship at a higher time ratio. Moreover, by setting the particle size ratio to 15 or more and 33 or less, it is possible to appropriately form a fluidized bed with an operation load that needs to maintain high desulfurization performance. Further, for example, by setting the particle size ratio to 15 or more, the range of the load in which the circulating fluidized bed S can be formed can be widened. Therefore, even if the load of the diesel engine 11 changes, the circulating fluidized bed S Can be suitably formed. For example, by setting the particle size ratio to 15 or more, the circulating fluidized bed S can be suitably formed even when the fluidized material P1 is worn and the average particle size of the fluidized material P1 is reduced.

  Further, in the dry desulfurization system 40, the desulfurization agent P2 floats together with the fluidizing material P1 by the flow of exhaust gas, and flows in the circulating fluidized bed S. Thus, since the desulfurization agent P2 floats and the dry desulfurization system 40 flows through the circulating fluidized bed S, the contact time of the desulfurization agent P2 with respect to the exhaust gas becomes long, and sulfur oxides can be efficiently removed from the exhaust gas. it can.

  The technical scope of the present invention is not limited to the above-described embodiment, and appropriate modifications can be made without departing from the spirit of the present invention. FIG. 4 is a diagram showing a dry desulfurization system 40A according to a modification. As shown in FIG. 4, the dry desulfurization system 40A has an exhaust gas circulation path (exhaust gas circulation section) L10.

  The exhaust gas circulation path L10 connects between the exhaust path L6 and the exhaust path L4. The exhaust gas circulation path L10 circulates and supplies the exhaust gas via the classifier 42 to the exhaust path L4. A flow rate adjustment valve 49 is provided in the exhaust gas circulation path L10. The flow rate adjustment valve 49 can adjust the flow rate of the exhaust gas flowing through the exhaust gas circulation path L10. It is also possible to prevent the exhaust gas from flowing through the exhaust gas circulation path L10 by closing the flow rate adjustment valve 49. With this configuration, the flow rate of the exhaust gas supplied to the desulfurization reactor 41 can be adjusted, so that the state of the circulating fluidized bed S can be adjusted to a suitable state. That is, even when the exhaust gas flow rate is small, more gas than the exhaust gas flow rate can be supplied to the desulfurization reactor 41. Thereby, the load range (exhaust gas flow rate range) of the marine engine capable of generating the circulating fluidized bed S can be increased.

  Moreover, in the said embodiment, although the case where the circulating fluidized bed S was formed with the fluidized material P1 was mentioned as an example, it did not limit to this, For example, the case where other fluidized beds, such as a bubble type fluidized bed, are formed Even so, the application of the present invention is possible.

  Moreover, in the said embodiment, although it was set as the structure which provides the bag filter 43, it is not limited to this, For example, it replaces with the bug filter 43 and the structure provided with the filter of the simple structure may be sufficient.

K internal K1 chamber K2 fluid part L1, L3 intake path L2, L4, L5, L6, L7, L8 exhaust path L9 exhaust gas recirculation path L10 exhaust gas circulation path P particulate matter P1 fluidizing material P2 desulfurizing agent R fluidizing material circulation part S circulation Fluidized bed 10 Exhaust gas treatment device 11 Diesel engine 12 Cylinder part 13 Scavenging trunk 14 Exhaust manifold 21 Cylinder 22 Intake port 23 Exhaust port 24 Injector 31 Exhaust turbine supercharger 32 Compressor 33 Turbine 34 Rotating shaft 35 Air cooler 40, 40A Dry desulfurization System 41 Desulfurization reactor 42 Classifier 43 Bag filter 44 Supply pipe 44a Downcomer 45 Desulfurization agent supply unit 45a Supply amount adjustment unit 46 Desulfurization agent recovery unit 47 Denitration device 48 Chimney 49 Flow control valve 51 Housings 52, 61, 71 Exhaust gas Entrance 53 Dispersion plates 54 and 62 73 exhaust gas outlet 63 flow material collecting section 73 filter section 74 separating portion 75 pipe 76 the tank section

Claims (8)

A dry desulfurization system for removing sulfur oxides from exhaust gas discharged from a marine engine,
A dry desulfurization reactor in which a fluidized material that is solid particles and is flowable when the exhaust gas has a predetermined flow rate is stored, and the exhaust gas passes through a region where the fluidized material is stored;
A desulfurization agent supply unit that supplies a solid particle desulfurization agent to a region where the fluidizing material is stored in the dry desulfurization reactor;
It is arranged downstream of the dry desulfurization reactor in the flow direction of the exhaust gas, separates the fluidizing material and the desulfurizing agent, supplies the fluidizing material to the dry desulfurization reactor, and the desulfurizing agent and the exhaust gas. And a classifier for discharging the exhaust gas downstream in the flow direction of the exhaust gas.   2. The dry desulfurization system according to claim 1, further comprising a filter disposed downstream of the classifier in the flow direction of the exhaust gas and collecting the desulfurization agent contained in the exhaust gas via the classifier.   The dry desulfurization system according to claim 2, further comprising a desulfurization agent recovery unit that recovers the desulfurization agent collected by the filter.   The relationship between the average particle size of the fluidized material and the average particle size of the desulfurizing agent satisfies 15 ≦ (average particle size of the fluidized material / average particle size of the desulfurized agent) ≦ 33. The dry desulfurization system according to any one of the above.   The said desulfurization agent supply part supplies the said desulfurization agent to the piping by which the said fluidized material classified with the said classifier is supplied to the said dry-type desulfurization reactor. Dry desulfurization system.   The supply amount adjustment part which adjusts the quantity of the said desulfurization agent supplied to the said dry-type desulfurization reactor from the said desulfurization agent supply part according to the flow volume of the said exhaust gas discharged | emitted from the said marine engine of Claims 1-5. The dry desulfurization system according to any one of the above.   The dry desulfurization system according to any one of claims 1 to 6, further comprising an exhaust gas circulation unit that supplies the exhaust gas that has passed through the classifier to the dry desulfurization reactor.   The dry desulfurization system according to any one of claims 1 to 7, and the dry desulfurization reactor that constitutes the dry desulfurization system, is provided on the downstream side in the flow direction of the exhaust gas, and nitrogen is oxidized from the exhaust gas. An exhaust gas treatment device comprising a denitration device for removing matter.

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