AT523651A4 - Exhaust aftertreatment device - Google Patents

Abstract

The invention relates to an exhaust gas aftertreatment device (5) for aftertreatment, in particular for desulfurization and dedusting, of exhaust gases from a ship's diesel engine on a ship, comprising a filter with at least one filter element (11), with two holders (12; 12a, for each filter element (11)) 12b) are provided, with which the filter element (11) is held in a lying, preferably essentially horizontal, state. The invention also relates to a method for the aftertreatment of the exhaust gases from a marine diesel engine (3).

Description

The invention relates to an exhaust gas aftertreatment device for aftertreatment, in particular dedusting and desulfurization, of the exhaust gases of a marine diesel engine on a ship, having a filter with at least one filter element. The invention further relates to a ship with a marine diesel engine and a method for aftertreatment, in particular dedusting and dedusting

sulphurization, of exhaust gases from a ship's diesel engine.

The operation of marine diesel engines with heavy fuel oil causes massive air pollution through sulfur oxide emissions (SOx), but also fine dust (soot) and unburned hydrocarbons. increasingly stricter rules for pollutant emissions from ships are being enacted. The IMO (International Maritime Organization) has decided to drastically reduce sulfur emissions. The sulfur emissions must then correspond to the values as if a fuel with a sulfur content of 0.5% were used. If heavy oil is to be retained as a fuel, an exhaust gas purification system may be required in the future. Otherwise, an (expensive) alternative fuel such as liquefied natural gas (LNG) or a so-called compliance fuel would have to be used, which has a sulfur content of less than

Less than 0.5% and therefore without a desulphurisation system

can be used.

For cleaning the engine exhaust gases, on the one hand, scrubber systems are known in the prior art, in which the exhaust gases are introduced into the washer and brought into contact with seawater. In the so-called “open-loop” process, the sulfur-containing exhaust gases are washed in a continuous process using the natural alkalinity of the seawater. The process water is discharged into the sea in accordance with the IMO specifications. In contrast, in a "closed-loop" process, the scrubber is operated as a closed circuit by adding an additive to the washing water for chemical-physical separation. The process water is stored in a tank. The introduction of process water can be completely avoided in specially protected areas. In addition, hybrid processes are also

se known, which is a combination of "open loop" and "clo-

Perform sed-Loop “processes in a washer. However, the use of a scrubber has the disadvantages that in the case of an “open-loop” application the system is heavily dependent on the alkalinity of the water, corrosion problems from washing water can occur and the energy consumption by seawater pumps is very high. "Open loop" systems are currently being gradually banned from ports because the effects of the washing water discharge have not been fully clarified. On the other hand, "closed-loop" systems also require several tanks. Hybrid systems, on the other hand, have a large space requirement for chemical and additive tanks. The more complex structure results in high installation times and costs. Usually there are structural changes to the ship

necessary.

Furthermore, dry sorption systems are known in the prior art, in which the exhaust gases are cleaned with the aid of a filter. An example of this is described in DE 10 2010 042 419 A1. In this prior art, the exhaust gas flow is passed through a fine dust filter in which sorbents are attached to the filter surface. A fabric filter can be provided as the fine dust filter. Furthermore, the challenge that the fine dust filter in ship operation should be insensitive to fluctuations, changes in position and pounding of the ship has already been addressed. In order to meet these requirements, a filter is used in which the filter cassettes are permanently installed with a filter fabric that is folded like a concertina. By installing spring elements and vibration dampers, vibration compensation should be achieved in relation to the ship's superstructure. However, due to the thin-walled structure of the filter cake, this harmonica-like design is only suitable for

Suitable for small amounts of dust. Accordingly, the object of the present invention is to alleviate or remedy the disadvantages of the prior art.

ben.

This task is accomplished by an exhaust gas aftertreatment device

according to claim 1, a ship according to claim 12 and a method

solved according to claim 14. Preferred embodiments are in

specified in the dependent claims.

According to the invention, brackets are provided for each filter element, with which the filter element in a lying, present

preferably essentially horizontal, state is kept.

Accordingly, the filter element is arranged in a lying state, including here an arrangement at an angle of less than 45 °, in particular less than 20 °, to the horizontal, preferably therefore in an essentially horizontal state,

should be understood.

This design of the filter has proven to be particularly suitable for withstanding the harsh conditions on the high seas. Wind and weather can cause the ship to list or roll. High forces act on the filter, which can be absorbed by the two-sided mounting of each filter element. The operation of the ship also places high loads on the filter. Strong vibrations can occur, which could damage conventional filters. Due to the lying, in particular horizontal, mounting of the elongated filter element, which has a longitudinal axis, over the mounts, the effects of vibrations are reduced to a minimum. Due to the brackets, the longitudinal axis of the filter element is fixed in the lying, preferably horizontal state (i.e. parallel to a horizontal walking surface on the ship). The filter can advantageously be used to remove sulfur compounds, in particular sulfur oxides (SOx), from the exhaust gases. At the same time, a development

dusting of the exhaust gases can be carried out.

The location and direction information such as "horizontal", "vertical", "top", "bottom", "side" etc. relate here to the intended operating state of the exhaust gas aftertreatment system on a horizontal subsurface, ie in ship operation with a horizontal central position of the Ship. Thus, a reliable

casual operation of the exhaust aftertreatment device on the

In order to be able to absorb the forces during operation on a ship, it is advantageous if a first holder for a first end of the filter element and a second holder for an opposite second end of the filter element are provided as holders. The brackets are designed to stabilize the filter element against horizontal and vertical vibrations.

bilize.

According to a preferred embodiment, the first holder has at least one horizontal holding element, in particular a holding plate, and / or a vertical holding element, in particular a vertical holding plate. It is particularly preferred if the first holder has two horizontal holding elements, one above and one below the filter element. In addition, it is advantageous if the first holder has two vertical holding elements on both sides of the filter element. Thus, horizontal

and vertical movements of the filter element are prevented.

In order to secure the second end of the filter element against upward and downward movements as well as lateral deflections, it is also advantageous if the second holder has a mounting element

having an opening for the second end of the filter element.

In a preferred embodiment, several filter elements are arranged one above the other in the lying, in particular horizontal, state. In addition, a plurality of filter elements are preferably arranged in the lying, in particular horizontal, state side by side, i.e. in a row. The filter elements are each fixed in their horizontal position by two brackets. The parallel alignment of the fil-

terelements are retained to each other.

To discharge the cleaned exhaust gas, it is advantageous if the filter has a clean gas space which is arranged laterally next to the at least one filter element. Preferred he

the clean gas space extends over several lying filter elements

te in the vertical direction upwards.

In order to achieve effective cleaning of the exhaust gases, a device for introducing a sorbent, in particular sodium bicarbonate or hydrated lime, into the exhaust gases is preferably provided in front of the filter. A lance is preferably provided for injecting the sorbent (also called sorbent) into the exhaust gas flow. A first part of the sorbent can already react with the sulfur oxides (SOx) during the flight time. However, a second part of the sulfur oxide separation from the exhaust gas takes place on the filter cake, i.e. on the residues that settle on the surface of the filter element during filtration. The sorbent loaded with the sulfur oxide is deposited on the filter element and can then be cleaned and removed from the filter

be carried out.

In a preferred embodiment, a cooling device for cooling the exhaust gases is provided in front of the filter. This can do that

The filter medium of the filter is spared.

In a preferred embodiment, a cleaning device for cleaning the filter, for example by means of

hitting the filter with compressed air, provided.

In a further preferred embodiment, a discharge device is provided for discharging solids deposited on the filter element. Depending on the design, the discharge device can have a push floor, a trough chain conveyor or a screw conveyor. These designs have a flat design in common, with which a disadvantage for the statics of the ship.

liger high center of gravity of the filter is avoided.

The filter element has a longitudinal axis, the length of the filter element (ie the extent of the filter element viewed in the direction of the longitudinal axis) by a multiple, in particular by a multiple, for example by more than five times, greater than its maximum width (ie its maximum extent lowering

right to the longitudinal axis). The horizontal arrangement of the filter element

ment refers to the longitudinal axis of the filter element.

In a preferred embodiment, the filter is designed as a hose filter, a filter hose being provided as the filter element. The filter hose can be formed from a fabric material. The bag filter preferably has a raw gas space, in particular on the upper side of the filter, and a clean gas space, in particular on the side next to the filter element. The exhaust gases are fed to the raw gas space of the bag filter, flow through the filter material, in particular fabric material, of the at least one filter tube and get into the clean gas space of the bag filter, from where the cleaned exhaust gases are discharged. The filter hose preferably has a first,

closed end and a second, open end.

The filter hose preferably has a greater, in particular several times greater, extent in the vertical direction than in the horizontal direction. In this embodiment, the filter hose is thus designed with a flattened cross-section. For example, the filter hose can have an oval cross

have cut.

The advantage of this version is its compactness. Much more filter bags can be accommodated, whereby the cleaning performance can be increased accordingly. Given the limited space on a ship, this advantage is particularly important. Due to the flattened, in particular oval, shape, there is hardly any dust left

lie on the filter bags.

A plurality of filter hoses are preferably arranged essentially parallel to one another. In addition, several rows of fil-

hoses can be arranged one above the other.

In an alternative embodiment, a hot gas filter element, in particular a ceramic filter element, is provided as the filter element. If the filter is designed as a hot gas filter,

the exhaust gases can have a temperature of more than 265 degrees

71725

Celsius (° C), in particular more than 300 ° C, filtered, i.e. deposited on a hot gas filter material such as ceramic or metal, cleaned and discharged. With this design, the cooling of the exhaust gases before filtering can be omitted. As a ceramic for the ceramic filter element, for example, silicon

carbide may be provided.

The exhaust gas aftertreatment device described above can be used on a ship in order to achieve the advantages already mentioned.

to achieve le.

In a preferred embodiment, the exhaust gas aftertreatment device is arranged within a chimney for releasing the exhaust gases to the environment. On the one hand, this design is favorable because the appearance of the ship is not impaired. Another advantage of this design is that the filter absorbs the noise of the ship's diesel engine. The chimney can therefore preferably be free of a silencer, which at

conventional ships.

The method for post-treatment, in particular dedusting and desulfurization, of exhaust gases from a ship's diesel engine has at least the following step:

Filtering the exhaust gases with the aid of a filter which has at least one filter element which is provided with brackets in a lying, preferably essentially horizontal, state

is held.

The method preferably also has the step: introducing a sorbent, in particular sodium bicar-

bonat, in the exhaust gases in front of the filter.

In addition, the method can include cooling the exhaust gases upstream of the filter. In order to protect the filter, the exhaust gases in this embodiment, viewed in the direction of flow, are cooled to a temperature of preferably less than essentially 250 degrees Celsius (° C.) upstream of the filter. Depending on the sorbent, the

Cooling of the exhaust gases after or before the introduction of the sorption

by means of taking place. The cooling can take place via ambient air or the introduction of water. If cooling via ambient air is provided, cooling air inlets can be provided in an exhaust pipe or a convection cooler. The convection cooler can be installed in front of the filter. The exhaust gas can be cooled to the target temperature via the airflow. With water cooling, treated seawater can be in the exhaust gas

canal be sprayed.

In a method for operating a ship, at least the following steps are carried out: operating a ship's diesel engine on a ship and supplying the exhaust gases from the ship's diesel engine to an exhaust gas

after-treatment device as described above.

The ship's diesel engine, preferably the ship's main drive, can be powered by heavy fuel oil (HFO), which can have a mass fraction of more than 1%, in particular more than 4%. The exhaust gases from the ship's diesel engine can contain at least 1000 mg of sulfur oxides (SOx) per standard cubic meter.

ter have.

The invention is explained below with reference to in the drawings

illustrated embodiments further explained.

Fig. 1 shows schematically a ship according to the invention, in which the exhaust gases of a ship's diesel engine with the help of an exhaust gas

after-treatment device to be cleaned. Fig. 2 shows schematically an exhaust gas aftertreatment device according to the invention, in which individual filter hoses one

Bag filter are held in a horizontal position.

Fig. 3 shows a further view of the exhaust gas aftertreatment pre-

direction according to FIG. 2.

Fig. 4 shows a detailed view of the exhaust gas aftertreatment device

device in the area of a holder for the filter hose.

Fig. 5 shows a detailed view of several horizontally side by side

the arranged filter bags.

Fig. 6 shows a system diagram of the ship.

7A shows a front view and FIG. 7B shows a side view of an embodiment variant in which the filter next to a

Chimney of the ship is arranged.

Fig. 7C shows a further variant in which the bag filter is completely inside the chimney of the ship.

is ordered.

Fig. 8 and Fig. 9 show an embodiment variant in which

ceramic filter candles are provided.

1 shows a ship 1 with a hull 2 in which a ship's diesel engine 3 (only shown schematically), in particular a ship's main propulsion engine, is arranged. The marine diesel engine 3 is operated with heavy oil, which can have a high sulfur content of up to 4.5%. When the ship's diesel engine 3 is in operation, exhaust gases are produced which are laden with dust and sulfur compounds, in particular sulfur oxides. The exhaust gases from the ship's diesel engine are fed to an exhaust gas aftertreatment device 5 via a line 4. After leaving the exhaust gas aftertreatment device 5, the cleaned exhaust gases are released into the environment (see arrow 6). Valves 7 are provided in the line 4 so that the exhaust gases can either be passed through the exhaust gas aftertreatment device 5 or released directly into the environment. The exhaust gas aftertreatment device 5 has a filter 8 with which the exhaust gases are filtered. In the embodiment shown, the exhaust gases are provided with a sorbent upstream of the filter 8 (see arrow 9). Part of the filter cake including the sorbate is discharged from the filter 8 (see arrow 10). For this purpose, a cleaning device can be provided for cleaning the filter 8, for example by applying compressed air to the filter 8.

hen be (not shown).

2 shows an embodiment of the filter 8 as a bag filter 8. The bag filter 8 accordingly has a plurality of filter elements 11 in the form of filter bags made of a fabric material, the filter bags each being arranged in a substantially horizontal state. At least two brackets 12 are provided per filter hose, which fix the respective filter hose essentially immovably in the horizontal state. The filter hoses are arranged one above the other in parallel and spaced apart from one another in the vertical direction. Furthermore, several filter hoses 11 can be arranged parallel to one another. The bag filter 8 has a raw gas space 13 on the top of the bag filter. A clean gas space 14 through which the cleaned exhaust gas is discharged is formed to the side of the filter hoses. A discharge device 15 is provided on the underside of the bag filter 8, with which material deposited on the filter bags is discharged (see also FIG. 3, in which the filter bags

che are not visible).

During operation, the exhaust gas from the ship's diesel engine 3 is directed into the raw gas space 13 of the bag filter and then hits the filter bags vertically in the filter space (see arrow

16 in Fig. 2). After the separation, the cleaned exhaust gas flows in a horizontal direction through the filter hoses into the clean gas space 14 (cf. arrows 17 in FIG. 2). Subsequently, the

gas withdrawn from the clean gas space 14.

4 and 5 schematically show the holders 12 with which the opposite, longitudinal ends of the filter bags are held in the horizontal position. A first holder 12a is provided at each of the one (first) ends of the filter bags. In the embodiment shown, the holder 12a has two horizontal holding elements 18a, for example holding plates, above and below one end of the filter hose. With the help of the holding elements 18a, one of the ends of the filter bags are framed on the top and bottom, so that the filter bag can be seen in the vertical direction

Is arranged essentially immovable.

In addition, the first holders 12a have vertical holding elements 18b, for example holding plates, at one (first) ends, which are each arranged between two horizontally adjacent filter hoses in order to also

wanted to prevent horizontal movement of the filter bags.

The horizontal holding elements 18a and / or the vertical holding elements 18b of the holder 12a can be arranged with a slight gap of preferably less than 1 cm, in particular less than 5 mm, for example 2 to 3 mm, to the filter hose in order to facilitate installation and to adjust tolerances -

same.

As can be seen from FIG. 4, second brackets 12b are provided at the other (second) ends of the filter bags on the side of the clean gas space 14, which, for example, as in WO

2012/135881 Al can be formed. Accordingly, the filter has a mounting plate (filter base) 27 with openings 28, in which the other (second) ends of the filter tubes are arranged essentially precisely in order to achieve a horizontal and vertical

le movement of the filter bags.

As can also be seen from FIG. 4, seals 29 are provided in the mounting plate 27 for sealing the filter hoses with respect to the openings 28. Furthermore, an injector nozzle 30 is provided, which serves on the one hand to conduct and accelerate the compressed air pulses originating from a device for emitting compressed air pulses, and on the other hand seals the filter hose against the opening 28 in the mounting plate. For this purpose, the injector nozzle 30 can have sealing elements on the outside at the level of the mounting plate 27 to form a defined gap for a defined compression of the filter hose between the sealing elements and the outer surface of the opening 28 in the mounting plate 27 and thus an automatic sealing of the filter hose 4 the opening 28

of the tube bottom 2 have.

Fig. 5 shows schematically several fil-

hoses. In the embodiment shown, the filter bags have a greater, in particular several times greater, extension in the vertical direction than in the horizontal direction. The filter hoses are thus designed with a flattened cross section, the filter hoses being arranged in a row. This allows the flow resistance and the resulting differential pressure to be optimized. Furthermore,

only a little dust collects.

6 shows a functional diagram from which further details of the exhaust gas aftertreatment device 5 can be seen. Accordingly, a device 20 for introducing the sorbent, in particular sodium bicarbonate, into the exhaust gases is provided upstream of the bag filter 8. The device 20 has a storage container 21, for example a silo or a big bag, for the sorbent (also called sorbent), which is introduced into the exhaust line 4 via a conveyor 22 and a metering unit 23 for the sorbent. In order to cool the exhaust gases to a temperature of less than 250 ° C., which is harmless to the bag filter 8, a cooling device 24 in the form of a heat exchanger or a quench for operation with air or water is arranged in front of the bag filter 8, viewed in the flow direction of the exhaust gases. The sorbate, dust and other solids are deposited on the bag filter via a discharge device 25. The cleaned exhaust gases are released into the environment via a chimney 26. The exhaust gas aftertreatment device 5 can in particular be set up to reduce the sulfur dioxide content from more than 1000 milligrams per standard cubic meter (mg / Nm3), for example 1500 mg / Nm3), to less than 250 mg / Nm3.

adorn.

Depending on the design, the bag filter can be installed in the vicinity of the chimney 26 (Fig. 4A) or inside the chimney 26 (Fig. 4B).

be lured. Thus, a method for the aftertreatment of the exhaust gases from the

Marine diesel engine 3 performed with the following steps

will:

Operating the marine diesel engine 3 with heavy fuel oil;

Discharging the exhaust gases from the marine diesel engine 3;

Introducing a sorbent, particularly sodium bicarbonate, into the exhaust gases;

Preferably cooling the exhaust gases; and then

Filtering the exhaust gases with the aid of a filter 8, in particular with the aid of a bag filter, which has at least a plurality of filter elements 11, in particular filter bags, each with two holders 12 in a substantially ho-

rizontal state are maintained.

An alternative embodiment is shown in FIGS. 8 and 9, the following merely referring to the differences

for the variant of FIGS. 4 and 5 have been included.

Accordingly, in the embodiment of FIGS. 8 and 9, elongated ceramic filter elements (filter candles) are provided as filter elements 11, which are held in the horizontal state with the holders 12. At one end, the first holders 12a are provided, which, as in the embodiment of FIGS. 4, 5, have individual horizontal holding elements 18a and vertical holding elements 18b. The other ends of the ceramic filter elements are fastened to the mounting plate 27 with the second brackets 12b.

Claims (17)

Patent claims: 1. Exhaust gas aftertreatment device (5) for aftertreatment, in particular for desulfurization and dedusting, of exhaust gases from a ship's diesel engine (3) on a ship (1), comprising: a filter (8) with at least one filter element (11), characterized in that for each filter element (11) holders (12; 12a, 12b) are provided, with which the filter element (11) in a lying state, preferably in a substantially horizontal len state, is maintained. 2. Exhaust aftertreatment device (5) according to claim 1, characterized in that a first holder (12a) for a first end of the filter element (11) and a second holder (12b) for an opposite second end of the Filter element (11) are provided. 3. exhaust gas aftertreatment device (5) according to claim 2, characterized in that the first holder (12a) has at least one horizontal holding element (18a), in particular a holding plate, and / or a vertical holding element (18b), in particular a vertical retaining plate. 4. exhaust gas aftertreatment device (5) according to claim 2 or 3, characterized in that the second holder (12b) has a mounting element (27) with an opening (28) for the second end of the Has filter element (11). 5. exhaust gas aftertreatment device (5) according to one of claims 1l to 4, characterized in that a plurality of filter elements (12) are arranged one above the other in the lying state. 6. exhaust gas aftertreatment device (5) according to one of claims 1l to 5, characterized in that the filter (8) has a clean gas space (14) which is located laterally next to the at least one NEN filter element (12) is arranged. 7. exhaust gas aftertreatment device (5) according to one of claims 1l to 6, characterized in that a device (20) for introducing a sorbent, in particular sodium bicarbonate nat, is provided in the exhaust gases in front of the filter (8). 8. exhaust gas aftertreatment device (5) according to one of claims 1l to 7, characterized in that a cooling device for Cooling of the exhaust gases is provided in front of the filter (8). 9. exhaust gas aftertreatment device (5) according to one of claims 1 to 8, characterized in that a discharge device (25) for discharging with the filter (8) deposited solid substances is provided. 10. exhaust gas aftertreatment device (5) according to one of claims 1l to 9, characterized in that a filter element (11) Filter hose is provided. 11. exhaust gas aftertreatment device (5) according to one of claims 1l to 9, characterized in that the filter element (11) is a hot gas filter element, in particular a ceramic filter element, is provided. 12. Ship (1) with a marine diesel engine (3), characterized by an exhaust gas aftertreatment device (5) according to one of claims 1 to 11. 13. Ship (1) according to claim 12, characterized by a chimney (26) for releasing the exhaust gases to the environment, wherein the exhaust gas aftertreatment device (5) is connected within the chimney (26) is arranged. 14. A method for aftertreatment, in particular dedusting and desulfurization, of exhaust gases from a ship's diesel engine (3), comprising the step: Filtering the exhaust gases with the aid of a filter (8) which has at least one filter element (11) with brackets (12) in a lying, preferably essentially horizontal len, state is held. 15. The method according to claim 14, characterized by: introducing a sorbent, in particular sodium bicar- bonat, in the exhaust gases in front of the bag filter (8). 16. The method according to claim 14 or 15, characterized by: Cooling of the exhaust gases in front of the filter (8). 17. Procedure with the steps: Operation of a marine diesel engine (3) on a ship (1) and Feeding the exhaust gases from the marine diesel engine (3) to an exhaust gas aftertreatment device (5) according to one of Claims 1 to 11.