CN212091636U - Exhaust cleaning system - Google Patents

Exhaust cleaning system Download PDF

Info

Publication number
CN212091636U
CN212091636U CN201922434856.0U CN201922434856U CN212091636U CN 212091636 U CN212091636 U CN 212091636U CN 201922434856 U CN201922434856 U CN 201922434856U CN 212091636 U CN212091636 U CN 212091636U
Authority
CN
China
Prior art keywords
scrubber
exhaust gas
scrubber fluid
cleaning system
gas cleaning
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201922434856.0U
Other languages
Chinese (zh)
Inventor
S.皮特斯
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Alfa Laval Corporate AB
Original Assignee
Alfa Laval Corporate AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to EP19210362 priority Critical
Priority to EP19210362.0 priority
Application filed by Alfa Laval Corporate AB filed Critical Alfa Laval Corporate AB
Application granted granted Critical
Publication of CN212091636U publication Critical patent/CN212091636U/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/02Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
    • F01N3/04Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust using liquids
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D53/00Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34Chemical or biological purification of waste gases
    • B01D53/46Removing components of defined structure
    • B01D53/48Sulfur compounds
    • B01D53/50Sulfur oxides
    • B01D53/501Sulfur oxides by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound
    • B01D53/504Sulfur oxides by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound characterised by a specific device
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D47/00Separating dispersed particles from gases, air or vapours by liquid as separating agent
    • B01D47/02Separating dispersed particles from gases, air or vapours by liquid as separating agent by passing the gas or air or vapour over or through a liquid bath
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D53/00Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34Chemical or biological purification of waste gases
    • B01D53/46Removing components of defined structure
    • B01D53/48Sulfur compounds
    • B01D53/50Sulfur oxides
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D53/00Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34Chemical or biological purification of waste gases
    • B01D53/46Removing components of defined structure
    • B01D53/54Nitrogen compounds
    • B01D53/56Nitrogen oxides
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D53/00Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34Chemical or biological purification of waste gases
    • B01D53/74General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/75Multi-step processes
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D53/00Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34Chemical or biological purification of waste gases
    • B01D53/74General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/77Liquid phase processes
    • B01D53/78Liquid phase processes with gas-liquid contact
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D53/00Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34Chemical or biological purification of waste gases
    • B01D53/74General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/77Liquid phase processes
    • B01D53/79Injecting reactants
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D53/00Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34Chemical or biological purification of waste gases
    • B01D53/96Regeneration, reactivation or recycling of reactants
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N13/00Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
    • F01N13/004Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 specially adapted for marine propulsion, i.e. for receiving simultaneously engine exhaust gases and engine cooling water
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/02Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
    • F01N3/0205Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust using heat exchangers
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2247/00Details relating to the separation of dispersed particles from gases, air or vapours by liquid as separating agent
    • B01D2247/04Regenerating the washing fluid
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2251/00Reactants
    • B01D2251/40Alkaline earth metal or magnesium compounds
    • B01D2251/402Alkaline earth metal or magnesium compounds of magnesium
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2251/00Reactants
    • B01D2251/60Inorganic bases or salts
    • B01D2251/604Hydroxides
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2252/00Absorbents, i.e. solvents and liquid materials for gas absorption
    • B01D2252/10Inorganic absorbents
    • B01D2252/103Water
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2252/00Absorbents, i.e. solvents and liquid materials for gas absorption
    • B01D2252/10Inorganic absorbents
    • B01D2252/103Water
    • B01D2252/1035Sea water
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2257/00Components to be removed
    • B01D2257/30Sulfur compounds
    • B01D2257/302Sulfur oxides
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2257/00Components to be removed
    • B01D2257/50Carbon oxides
    • B01D2257/504Carbon dioxide
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2258/00Sources of waste gases
    • B01D2258/01Engine exhaust gases
    • B01D2258/012Diesel engines and lean burn gasoline engines
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2259/00Type of treatment
    • B01D2259/45Gas separation or purification devices adapted for specific applications
    • B01D2259/4566Gas separation or purification devices adapted for specific applications for use in transportation means
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2240/00Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being
    • F01N2240/02Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being a heat exchanger
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2560/00Exhaust systems with means for detecting or measuring exhaust gas components or characteristics
    • F01N2560/07Exhaust systems with means for detecting or measuring exhaust gas components or characteristics the means being an exhaust gas flow rate or velocity meter or sensor, intake flow meters only when exclusively used to determine exhaust gas parameters
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2560/00Exhaust systems with means for detecting or measuring exhaust gas components or characteristics
    • F01N2560/12Other sensor principles, e.g. using electro conductivity of substrate or radio frequency
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2590/00Exhaust or silencing apparatus adapted to particular use, e.g. for military applications, airplanes, submarines
    • F01N2590/02Exhaust or silencing apparatus adapted to particular use, e.g. for military applications, airplanes, submarines for marine vessels or naval applications
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2610/00Adding substances to exhaust gases
    • F01N2610/14Arrangements for the supply of substances, e.g. conduits
    • F01N2610/1406Storage means for substances, e.g. tanks or reservoirs
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2610/00Adding substances to exhaust gases
    • F01N2610/14Arrangements for the supply of substances, e.g. conduits
    • F01N2610/1426Filtration means
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2610/00Adding substances to exhaust gases
    • F01N2610/14Arrangements for the supply of substances, e.g. conduits
    • F01N2610/1433Pumps
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/10Greenhouse gas [GHG] capture, material saving, heat recovery or other energy efficient measures, e.g. motor control, characterised by manufacturing processes, e.g. for rolling metal or metal working

Abstract

An exhaust gas cleaning system is provided for cleaning exhaust gas on a marine vessel. The exhaust gas cleaning system includes: a scrubber arranged to scrub the exhaust gas with scrubber fluid circulating through the scrubber; and a first heat exchanger arranged in communication with the scrubber to cool scrubber fluid circulating through the scrubber. Further, the exhaust gas cleaning system includes: a circulation tank arranged in communication with the scrubber to feed scrubber fluid to the scrubber and to receive scrubber fluid from the scrubber; and a cleaning unit arranged in communication with the circulation tank to receive scrubber fluid from the circulation tank and separate it into first and second portions, the second portion being more contaminated than the first portion. The exhaust gas cleaning system is characterized by further comprising: a heating device arranged in communication with the circulation tank and the cleaning unit to heat the scrubber fluid after it exits the circulation tank and before it is received by the cleaning unit.

Description

Exhaust cleaning system
Technical Field
The present invention relates to an exhaust gas cleaning system for cleaning exhaust gases on a marine vessel, for example from a marine engine, burner or boiler.
Background
Large ships are typically driven by engines that run on sulfur-containing fuels. In the combustion of such fuels, Sulfur Oxide (SO) is formedX) To exhaust gas. The exhaust gas typically also contains particulate matter (e.g., soot, oil, and heavy metals) and Nitrogen Oxides (NO)X). To reduce the environmental impact of the exhaust gas, the exhaust gas should be cleaned prior to release into the atmosphere. For example, the exhaust gas may pass through a scrubber to be scrubbed with scrubber fluid, whereby contaminants in the exhaust gas are captured in the scrubber fluid.
The scrubber may be a so-called open loop scrubber and the scrubber fluid may be seawater, wherein the natural alkalinity of the seawater is used to wash sulfur oxides from the exhaust gas. Seawater is then fed from the ocean through a scrubber to absorb SO from the exhaust gas before it is discharged directly back to the oceanXAnd a particulate material.
Alternatively, the scrubber may be a so-called closed-loop scrubber using recycled fresh or sea water with an alkaline agent such as sodium hydroxide (NaOH) or sodium carbonate (Na)2CO3) As a scrubber fluid to wash out sulfur oxides and particulate matter from the exhaust gas. In such scrubbers, the amount of hydrous sulfite, sulfate and particulate matter in the circulating fresh or sea water gradually increases. Thus, in order to control the quality of the circulating fresh water or seawater, small amounts thereof may be occasionally or continuously replaced with clean fresh water or seawater and stored on board the vessel or discharged overboard after being cleaned of particulate matter.
When the hot exhaust gas comes into contact with the scrubber fluid inside the scrubber, it is cooled and a large amount of water contained in the scrubber fluid is evaporated. This evaporated water leaves the scrubber with the exhaust gas and may produce an undesirable visible plume when it comes into contact with ambient air conditions. According to a known solution to this problem, the exhaust gas containing evaporated water is heated before it is released from the vessel, so that the plume is less visible. However, the equipment used for this heating is large and expensive. It also consumes a lot of energy, which is negative from an environmental point of view.
SUMMERY OF THE UTILITY MODEL
It is an object of the present invention to provide an exhaust gas cleaning system for cleaning exhaust gases on a marine vessel, which at least partly solves the above mentioned problems. The basic concept of the invention is to cool the exhaust gas more inside the scrubber to reduce the amount of evaporated water leaving the scrubber with the exhaust gas. An exhaust system according to the present invention is discussed below.
The exhaust gas cleaning system according to the invention is arranged for cleaning exhaust gases on a marine vessel. The exhaust gas cleaning system comprises a scrubber arranged to scrub the exhaust gas with scrubber fluid circulating through the scrubber. The exhaust gas cleaning system further includes a first heat exchanger, a circulation tank, and a cleaning unit. The first heat exchanger is arranged in communication with the scrubber for cooling scrubber fluid circulating through the scrubber. The circulation tank is arranged in communication with the scrubber for feeding scrubber fluid to the scrubber and for receiving scrubber fluid from the scrubber. The cleaning unit is arranged in communication with the circulation tank for receiving the scrubber fluid from the circulation tank and for separating it into a first and a second portion, the second portion being more contaminated, i.e. containing more particulate matter, than the first portion. The exhaust gas cleaning system is characterized in that it further comprises a heating device. A heating device is arranged in communication with the circulation tank and the cleaning unit for heating the scrubber fluid after it leaves the circulation tank and before it is received by the cleaning unit.
The exhaust gas cleaning system may be arranged for cleaning exhaust gas from a marine engine on a vessel, a marine burner on a vessel or a marine boiler on a vessel.
It should be emphasized that "communicating" and "communication" throughout the text mean "directly or indirectly communicating" and "directly or indirectly communicating", respectively. Similarly, "receiving", "feeding" and the like throughout the text mean "receiving directly or indirectly" and "feeding directly or indirectly", respectively.
Since scrubber fluid circulates through the scrubber via the circulation tank of the exhaust gas cleaning system of the present invention, the scrubber is a so-called closed-loop scrubber. As previously mentioned, closed loop scrubbers typically operate using scrubber fluid in which fresh and/or seawater is mixed with a suitable alkaline agent.
The cleaning unit may be arranged to receive a constant or intermittent flow of scrubber fluid from the circulation tank, and this flow may vary over time.
The cleaning unit may comprise one or more separators and/or filters, for example a centrifugal separator (such as a high speed separator) and/or a decanter, and/or a membrane filter.
As described above, in the exhaust gas cleaning system according to the present invention, the cooling of the exhaust gas is increased to reduce the amount of water of the scrubber fluid evaporated inside the scrubber. This increased exhaust gas cooling is obtained by increasing the cooling of the scrubber fluid circulating through the scrubber by means of the first heat exchanger. Of course, depending on prevailing ambient air conditions, an exhaust gas containing more water vapor will generally produce a more visible plume upon leaving the boat than an exhaust gas containing less water vapor. By reducing the amount of water evaporated inside the scrubber, the amount of water vapor leaving the vessel with the exhaust gas will be reduced, which may result in less visible plume from the vessel.
As mentioned by way of introduction, for closed loop scrubbers, scrubber fluid may need to be replaced to control the quality of the circulating scrubber fluid. The scrubber fluid to be replaced may be cleaned of particulate matter and then discharged into the ocean or into a storage tank depending on the prevailing circumstances. In order to be discharged, the scrubber fluid may have to meet certain criteria, for example, it must not have a pH value that is too low and/or a turbidity value that is too high. Depending on the alkaline agent contained in the scrubber fluid, the reduced temperature of the scrubber fluid may cause the solubility of the alkaline agent to deteriorate and thus cause undissolved alkaline agent to be removed along with the particulate matter during the treatment of the scrubber fluid in the cleaning unit. Naturally, this is a waste of unused chemicals. Furthermore, again depending on the alkaline agent contained in the scrubber fluid, the alkaline agent may cause the scrubber fluid to have a high turbidity value, which may prevent the scrubber fluid from being discharged.
Since the exhaust gas cleaning system according to the invention comprises heating means to heat the scrubber fluid after it leaves the circulation tank and before it is received by the cleaning unit, the scrubber fluid to be replaced can be heated before it is processed by the cleaning unit. The heating of the scrubber fluid may increase the solubility of the alkaline agent, which may prevent the alkaline agent from eventually being in the more heavily contaminated second portion and being wasted. Additionally/alternatively, heating of the scrubber fluid may reduce its turbidity value, which may enable a cleaner first portion of the scrubber fluid to be discharged.
The exhaust gas cleaning system may further comprise means for supplying an alkaline agent to the scrubber fluid. Thus, the alkaline agent may be replenished as appropriate in order to optimize the efficiency of the exhaust gas cleaning system. For example, the means for supplying alkaline agent to the scrubber fluid may be arranged upstream of the circulation tank and downstream of the scrubber, i.e. replenishment of the alkaline agent may be performed.
The alkaline agent may include various chemicals, such as magnesium oxide or magnesium carbonate. According to one embodiment of the invention, the alkaline agent comprises magnesium hydroxide, which has the following advantages: the degree of crystallization of the sulphate formed in the scrubber fluid is low even at low temperatures of the scrubber fluid.
The means for supplying alkaline agent to the scrubber fluid may comprise a source of alkaline agent and a pump for pumping alkaline agent from the source to the scrubber fluid. The source of alkaline agent may simply be a container containing the alkaline agent. The pump may be a progressive cavity pump which may reduce erosion from any abrasive alkaline agent. In addition, screw pumps are relatively less prone to clogging.
The exhaust gas cleaning system may further comprise a measuring device arranged for measuring a value of a property of the scrubber fluid, which value may be lower, equal or higher than a predetermined value. The treatment of the scrubber fluid may depend on the output of the measurement device.
The measuring device may be arranged in communication with the heating device and the cleaning unit for measuring said property value of the scrubber fluid after the scrubber fluid has been heated by the heating device and before it is received by the cleaning unit. The treatment of the cleaner first portion of the scrubber fluid may depend on the output of the measurement device.
The measuring means may comprise a mass flow meter and the characteristic may be the density of the scrubber fluid. The density of the scrubber fluid depends on the salt content of the scrubber fluid.
The mass flow meter may be of any suitable type. According to one embodiment of the invention, the mass flow meter is a Coriolis mass flow meter having the following advantages: it is an online mass flow meter.
Alternatively or additionally, the measuring device may comprise a conductivity sensor and the characteristic may be the conductivity of the scrubber fluid. The conductivity of the scrubber fluid depends on the salt content of the scrubber fluid.
The cleaning unit may be in communication with the circulation tank for feeding at least some of the first portion, i.e. a portion, of the scrubber fluid to the circulation tank in case the property value is below the predetermined value. If the value is relatively low, the salt content of the scrubber fluid may be relatively low, and the discharge of the cleaner first portion of the scrubber fluid may not be necessary for proper operation of the exhaust gas cleaning system. The cleaning unit may be arranged to feed a constant or intermittent flow of scrubber fluid to the circulation tank, and this flow may vary over time.
The exhaust gas cleaning system may further comprise a water analysis unit arranged to determine a parameter value for the number of first portions of scrubber fluid ≧ 1. The processing of the cleaner first portion of the scrubber fluid may depend on the output of the water analysis unit. The parameter values determined by the water analysis unit may for example be the turbidity, the pH and the PAH concentration of the first part of the scrubber fluid.
The cleaning unit may be in communication with the circulation tank for feeding at least some of the first portion, i.e. a portion, of the scrubber fluid to the circulation tank in case at least one of said parameter values exceeds or equals a respective limit value. Thus, if a certain criterion is not fulfilled, i.e. if the first portion is not clean enough, the draining of the first portion of the scrubber fluid may be prevented, which is beneficial from an environmental point of view. The cleaning unit may be arranged to feed a constant or intermittent flow of scrubber fluid to the circulation tank, and this flow may vary over time.
Thus, the cleaning unit may be arranged to: feeding at least some of the first portion of scrubber fluid to the circulation tank in case the property value is below the predetermined value and/or at least one of the parameter values exceeds or equals a respective limit value.
As mentioned above, the exhaust gas cleaning system may further comprise a water analysis unit arranged to determine a parameter value for the number of first portions of scrubber fluid ≧ 1. Furthermore, the exhaust gas cleaning system may be arranged to: in case each of said parameter values is below a respective limit value and/or said characteristic value is above or equal to said predetermined value, at least some, i.e. a part, of the first portion of the scrubber fluid is discharged. For example, the first portion of the scrubber fluid may be discharged overboard, or to a temporary storage tank for later discharge overboard. The drained fluid can be replaced with fresh scrubber fluid. Thus, the salt concentration of the scrubber fluid circulating through the scrubber may be kept low enough for proper operation of the exhaust gas cleaning system.
The heating device for heating the scrubber fluid before it is received by the cleaning unit may comprise a second heat exchanger.
The first and second heat exchangers may be of any suitable type, such as plate heat exchangers or shell and tube heat exchangers. Furthermore, the first and second heat exchangers may be of the same type or of different types.
Other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings.
Drawings
The invention will now be described in more detail with reference to the accompanying schematic drawings, in which
FIG. 1 is a block diagram schematically illustrating an exhaust gas cleaning system according to the present invention.
Detailed Description
Fig. 1 shows an exhaust gas cleaning system 1 comprising a first plate heat exchanger 3, a circulation tank 5, a scrubber 7, a heating device 9 in the form of a second plate heat exchanger 9', a cleaning unit 11, a water analysis unit 13, a measuring device 15 in the form of a coriolis mass flowmeter 15', and a device 17 for supplying an alkaline agent, here magnesium hydroxide. In turn, the means 17 for supplying alkaline agent comprise: an alkaline agent source 19, more specifically a container containing an alkaline agent (here, magnesium hydroxide); and a screw pump 21. The exhaust gas cleaning system 1 is configured to clean exhaust gas EG from a marine diesel engine 23 on a marine vessel (not shown).
Inside the scrubber 7, which works in a conventional manner not further described herein, the exhaust gas EG is scrubbed with a scrubber fluid SF in the form of fresh water mixed with magnesium hydroxide. Thus, the scrubber 7 comprises an exhaust gas inlet 25 for receiving exhaust gas EG from the engine 23 and an exhaust gas outlet 27 for releasing scrubbed exhaust gas EGW. Scrubber fluid SF is fed from circulation tank 5 to scrubber 7, passes through scrubber 7 to absorb contaminants from exhaust EG to clean exhaust EG, returns to circulation tank 5, then again to scrubber 7, and so on.
The exhaust gas EG discharged from the engine 23 is very hot and, in order to maintain a suitable temperature of the scrubber fluid SF, the exhaust gas EG is cooled by means of seawater in the first plate heat exchanger 3 arranged upstream of the scrubber 7 and downstream of the circulation tank 5, i.e. on its path from the circulation tank 5 to the scrubber 7. Due to the high temperature of the exhaust gas EG, water contained in the scrubber fluid SF evaporates when the scrubber fluid contacts the exhaust gas EG inside the scrubber 7. The formed water vapour leaves the scrubber 7 and is discharged from the vessel through a stack together with the cleaned exhaust gas EGW. In order to reduce the visible plume formed by this moist cleaned exhaust gas when it is released into the atmosphere, the scrubber fluid SF recirculated through the scrubber 7 is more cooled than conventionally by means of the first plate heat exchanger 3. As a result, less water is evaporated inside the scrubber, which results in less humid cleaned exhaust gas and thus less visible plume.
As the scrubber fluid SF is recirculated through the scrubber 7, it becomes increasingly contaminated. To ensure efficient operation of the scrubber 7, the scrubber fluid must not be too contaminated. Thus, some scrubber fluid SF is continuously pumped from the circulation tank 5 to the cleaning unit 11 for cleaning. The cleaning unit 11 is a high-speed separator arranged to separate the contaminated scrubber fluid into a cleaner first part SF1 and a more contaminated second part SF 2. A second portion of SF2 is fed to slurry tank 29 for subsequent disposal. In order to ensure that there is a sufficient amount of scrubber fluid in the circulation tank 5, it is supplemented with scrubber fluid to compensate for the pumped out scrubber fluid. Such replenishment may include adding clean fresh water from outside the exhaust gas cleaning system 1. In this case, in order to maintain the properties of the scrubber fluid suitable for the correct operation of the exhaust system 1, the scrubber fluid replenishment will typically also comprise supplying the scrubber fluid with magnesium hydroxide. The magnesium hydroxide is then pumped from the source 19 to the scrubber fluid by means of a screw pump 21. The supply of magnesium hydroxide is performed downstream of the scrubber 7 and upstream of the circulation tank 5. The scrubber fluid replenishment may alternatively/additionally be "internal", in which case a cleaner first part SF1 of the scrubber fluid SF is returned from the cleaning unit 11 to the circulation tank 5. This will be discussed further below.
As previously mentioned, the use of magnesium hydroxide as an alkaline agent allows the scrubber fluid circulating through the scrubber to be cooled more than conventionally without the problems associated with crystallization. However, the relatively low solubility of magnesium hydroxide in water may result in scrubber fluid containing undissolved magnesium hydroxide. In order to avoid feeding such undissolved magnesium hydroxide into the cleaning unit 11 and eventually being discarded in the more contaminated second part SF2 of the scrubber fluid SF, the scrubber fluid to be treated by the cleaning unit 11 is heated in a second heat exchanger 9' arranged upstream of the cleaning unit 11 and downstream of the circulation tank 5, i.e. on its path from the circulation tank 5 to the cleaning unit 11, by means of water from the heat recovery system of the vessel. By this heating, undissolved magnesium hydroxide in the scrubber fluid is dissolved and thus ends up in the cleaner first part SF1 of the scrubber fluid SF, which cleaner first part SF1 can be returned to the circulation tank 5 as previously described.
As mentioned above, the more heavily contaminated second portion of the scrubber fluid SF2 is fed to the slurry tank 29. The occurrence of the cleaner first part SF1 depends on different factors, such as the characteristics of the cleaner first part SF 1. As the scrubber fluid is recirculated through the scrubber, the amount of sulfate in the scrubber fluid gradually increases. To ensure proper operation of the exhaust gas cleaning system 1, the salt content of the circulated scrubber fluid cannot be too high. For this purpose, the density of the scrubber fluid SF to be treated by the cleaning unit 11 is measured by means of a Coriolis mass flowmeter 15' arranged upstream of the cleaning unit 11 and downstream of the second plate heat exchanger 9' (i.e. on its path from the second plate heat exchanger 9' to the cleaning unit 11). If the density is higher than or equal to the predetermined value, the salt content in the scrubber fluid is so high that a cleaner first part of the scrubber fluid SF1 should be emitted or discharged from the exhaust gas cleaning system 1 according to its further characteristics. However, if the density is below a predetermined value, the discharge of the first part SF1 of the scrubber fluid SF is not necessary and the first part SF1 is changed back to the circulation tank 5 in the "internal" make-up of the scrubber fluid.
The bleeding or discharging of the first portion SF1 from the exhaust gas cleaning system 1 is only performed when the density of the scrubber fluid is sufficiently high and the first portion SF1 of the scrubber fluid SF meets certain criteria. This condition satisfying a certain criterion is checked by a water analyzing unit 13 arranged downstream of the cleaning unit 11 and upstream of the circulation tank 5. The water analysis unit 13 is arranged to determine turbidity values, pH values and PAH (polycyclic aromatic hydrocarbons) concentrations of the first part SF1 of the scrubber fluid SF. If one or more of the turbidity value, the pH value and the PAH concentration exceeds or equals the respective limit values, e.g. 25 NTU, 6.5(6,5) and 2250 ppb, respectively, the discharge of the first part SF1 of the scrubber fluid SF is not performed and the first part SF1 is instead returned to the circulation tank 5 in the "internal" makeup of the scrubber fluid. However, if the turbidity value, the pH value and the PAH value are all below the respective limit values and the density of the scrubber fluid is sufficiently high, the first fraction is let out or discharged overboard from the exhaust gas cleaning system 1, or to a temporary storage tank (not shown) for later discharge, for example in case the vessel is in an area where overboard discharge is prohibited.
Thus, the scrubber fluid circulating through the scrubber is cooled more than normal, for example to 6 ℃, to reduce visible plumes from the ship's stack. To enable such low scrubber fluid temperatures without disturbing the crystallization, magnesium hydroxide is used as alkaline agent. In order to prevent undissolved magnesium hydroxide from ending up in the reject fraction, i.e. the second fraction SF2 from the cleaning unit, the scrubber fluid to be treated in the cleaning unit is heated to e.g. 35 ℃ by means of the second plate heat exchanger before being fed to the cleaning unit. In addition to dissolving undissolved magnesium hydroxide in the scrubber fluid to be treated by the cleaning unit, the heating of the scrubber fluid reduces the turbidity of the scrubber fluid, and thus of the first portion of the scrubber fluid SF1, such that a sufficiently low turbidity value may be obtained to allow easier tapping or draining of the first portion of the scrubber fluid.
As mentioned before, the scrubber fluid circulating through the scrubber may be cooled by means of seawater, and naturally the seawater must be sufficiently cold in order to be able to achieve more cooling than conventionally. As also previously mentioned, the visibility of the plume is dependent on ambient air conditions, for example the plume is generally more visible when the ambient air temperature is low. Typically, low sea water temperatures are associated with low ambient air temperatures, which means that the exhaust gas cleaning system described above is most effective when most needed.
The components of the exhaust gas cleaning system described above are connected by suitable conduits to allow them to communicate in the specific manner described above. Furthermore, the above-mentioned exhaust system may comprise further components to make it work properly, such as pumps, valves, sensors, further water analysis units, control units, switching modules, etc. As an example, the exhaust system may include a pH meter or sensor between the scrubber and the circulation tank for measuring the pH of the scrubber fluid. The pH meter may be in communication with a supply 17 to supply magnesium hydroxide to the scrubber fluid when appropriate. The supply device 17 may additionally/alternatively be operated in response to the sulphur dioxide/carbon dioxide ratio of the cleaned exhaust gas.
The above-described embodiments of the invention should be considered as examples only. Those skilled in the art realize that the embodiments discussed can be varied in a number of ways without departing from the inventive concept.
As an example, the exhaust gas cleaning system may be operated with other alkaline agents than magnesium hydroxide, magnesium oxide. Furthermore, other chemicals than alkaline agents may be added to the scrubber fluid for optimized operation of the exhaust gas cleaning system, such as flocculants or coagulants to increase the efficiency of the cleaning unit 11.
The supply means 17 for supplying magnesium hydroxide to the scrubber fluid need not be arranged upstream of the circulation tank 5 and downstream of the scrubber 11, but may be arranged elsewhere, for example directly connected to the circulation tank 5.
In the above embodiments, the treatment of the first portion of the scrubber fluid is dependent on the density of the scrubber fluid after heating, as well as the turbidity value, pH value and PAH concentration of the first portion of the scrubber fluid. In alternative embodiments, the treatment of the first portion of the scrubber fluid may depend on only one or two of these parameters, additional parameters, and/or other parameters.
The scrubber fluid need not include fresh water and alkaline agent, but may instead include seawater and alkaline agent or a combination thereof.
The flow of scrubber fluid from the circulation tank to the cleaning unit need not be continuous, but may be intermittent and performed at regular intervals or only when appropriate.
The first plate heat exchanger 3 does not have to be arranged upstream (i.e. before) the scrubber and downstream (i.e. after) the circulation tank, but may instead be arranged downstream of the scrubber and upstream of the circulation tank.
The heating device 9 does not have to have the form of a second plate heat exchanger 9' but may have any form. For example, the heating device 9 may alternatively/additionally comprise an electric heater.
The scrubber fluid to be treated by the cleaning unit 11 does not have to be heated by means of water from the heat recovery system of the vessel, but may be heated by means of hot water or water vapour from any suitable source.
The measuring device 15 need not be in the form of a Coriolis mass flowmeter 15', but may be of any form. For example, the measuring device 15 may alternatively/additionally comprise a conductivity sensor.
It should be emphasized that the description of details not relevant to the present invention has been omitted and the drawings are purely schematic and not drawn to scale.

Claims (15)

1. An exhaust gas cleaning system (1) for cleaning Exhaust Gas (EG) on a marine vessel, the exhaust gas cleaning system (1) comprising:
a scrubber (7), the scrubber (7) being arranged to scrub the Exhaust Gas (EG) with Scrubber Fluid (SF) circulating through the scrubber (7),
a first heat exchanger (3), the first heat exchanger (3) being arranged in communication with the scrubber (7) for cooling Scrubber Fluid (SF) circulating through the scrubber (7),
a circulation tank (5), the circulation tank (5) being arranged in communication with the scrubber (7) for feeding Scrubber Fluid (SF) to the scrubber (7) and for receiving Scrubber Fluid (SF) from the scrubber (7), and
a cleaning unit (11), the cleaning unit (11) being arranged in communication with the circulation tank (5) for receiving Scrubber Fluid (SF) from the circulation tank (5) and separating it into a first portion (SF1) and a second portion (SF2), the second portion (SF2) being more contaminated than the first portion (SF1),
characterized in that the exhaust gas cleaning system (1) further comprises a heating device (9), the heating device (9) being arranged in communication with the circulation tank (5) and the cleaning unit (11) for heating the Scrubber Fluid (SF) after it leaves the circulation tank (5) and before it is received by the cleaning unit (11).
2. The exhaust gas cleaning system (1) according to claim 1, characterized in that the exhaust gas cleaning system (1) further comprises means (17) for supplying an alkaline agent to the Scrubber Fluid (SF).
3. The exhaust gas cleaning system (1) according to claim 2, characterized in that the alkaline agent comprises magnesium hydroxide.
4. The exhaust gas cleaning system (1) according to any one of claims 2-3, characterized in that the means (17) for supplying alkaline agent to the Scrubber Fluid (SF) comprises a source (19) of alkaline agent and a pump (21) for pumping alkaline agent from the source (19) of alkaline agent to the Scrubber Fluid (SF).
5. The exhaust gas cleaning system (1) according to claim 4, characterized in that the pump (21) is a screw pump.
6. The exhaust gas cleaning system (1) according to any one of claims 1-3, characterized in that the exhaust gas cleaning system (1) further comprises a measuring device (15), which measuring device (15) is arranged for measuring a value of a property of the Scrubber Fluid (SF), which value may be lower, equal or higher than a predetermined value.
7. The exhaust gas cleaning system (1) according to claim 6, characterized in that the measuring device (15) is arranged in communication with the heating device (9) and the cleaning unit (11) for measuring the value of the property of the Scrubber Fluid (SF) after the Scrubber Fluid (SF) is heated by the heating device (9) and before the Scrubber Fluid (SF) is received by the cleaning unit (11).
8. The exhaust gas cleaning system (1) according to claim 6, characterized in that the measuring device (15) comprises a mass flow meter (15') and the property is the density of the Scrubber Fluid (SF).
9. The exhaust gas cleaning system (1) according to claim 8, characterized in that the mass flow meter (15') is a Coriolis mass flow meter.
10. The exhaust gas cleaning system (1) according to claim 6, characterized in that the measuring device (15) comprises a conductivity sensor and the property is the conductivity of the Scrubber Fluid (SF).
11. The exhaust gas cleaning system (1) according to claim 6, characterized in that the cleaning unit (11) is in communication with the circulation tank (5) for feeding at least some of the first portion (SF1) of Scrubber Fluid (SF) to the circulation tank (5) in case the value of said property is lower than said predetermined value.
12. The exhaust gas cleaning system (1) according to any one of claims 1-3, characterized in that the exhaust gas cleaning system (1) further comprises a water analysis unit (13), the water analysis unit (13) being arranged to determine a parameter value for which the number of first portions (SF1) of the Scrubber Fluid (SF) is ≧ 1.
13. The exhaust gas cleaning system (1) according to claim 12, characterized in that the cleaning unit (11) is in communication with the circulation tank (5) for feeding at least some of the first portion (SF1) of Scrubber Fluid (SF) to the circulation tank (5) in case at least one of said parameter values exceeds or equals a respective limit value.
14. The exhaust gas cleaning system (1) according to claim 6, characterized in that the exhaust gas cleaning system (1) further comprises a water analyzing unit (13), the water analyzing unit (13) being arranged to determine a parameter value for which the number of first portions (SF1) of the Scrubber Fluid (SF) is larger than or equal to 1, wherein the exhaust gas cleaning system (1) is arranged to: -discharging at least some of the first portion (SF1) of Scrubber Fluid (SF) in case each of said parameter values is below a respective limit value and/or the value of said characteristic is above or equal to said predetermined value.
15. The exhaust gas cleaning system (1) according to any one of claims 1-3, characterized in that the heating device (9) comprises a second heat exchanger (9').
CN201922434856.0U 2019-11-20 2019-12-30 Exhaust cleaning system Active CN212091636U (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP19210362 2019-11-20
EP19210362.0 2019-11-20

Publications (1)

Publication Number Publication Date
CN212091636U true CN212091636U (en) 2020-12-08

Family

ID=68621164

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201922434856.0U Active CN212091636U (en) 2019-11-20 2019-12-30 Exhaust cleaning system

Country Status (7)

Country Link
JP (1) JP3232219U (en)
KR (1) KR20210001193U (en)
CN (1) CN212091636U (en)
DE (1) DE202020106421U1 (en)
DK (1) DK202000116U3 (en)
FR (1) FR3102939B3 (en)
GR (1) GR2003188Y (en)

Also Published As

Publication number Publication date
GR2003188Y (en) 2021-03-18
DK202000116U3 (en) 2021-02-23
DE202020106421U1 (en) 2020-11-20
FR3102939A3 (en) 2021-05-14
KR20210001193U (en) 2021-05-31
FR3102939B3 (en) 2021-11-12
JP3232219U (en) 2021-06-03

Similar Documents

Publication Publication Date Title
JP6042551B2 (en) Combined cleaning system and method for the reduction of SOX and NOX in exhaust gas from combustion engines
JP6189977B2 (en) Cleaning system and cleaning method for reducing SOx in exhaust gas
FI118576B (en) A method and arrangement for purifying exhaust gas from a watercraft internal combustion engine
CN212091636U (en) Exhaust cleaning system
DK201900059U3 (en) CLEANING SYSTEM AND USE
CN210993612U (en) Cleaning system
RU2760725C1 (en) System for purifying off-gas and method for purifying off-gas
JP3223498U (en) Purification system
DK201900097U3 (en) System for generating power on board a ship
KR200493729Y1 (en) Cleaning system, method and use
KR102266245B1 (en) Water Treatment System For a Ship including Exhaust Gas Purification Device
KR20220009640A (en) Apparatus for reducing water and air pollutant
CN114430698A (en) Marine exhaust gas treatment device
Adithya Babu et al. WASTE HEAT RECOVERY INTEGRATED SYSTEM

Legal Events

Date Code Title Description
GR01 Patent grant
GR01 Patent grant