Desulfurization tower and desulfurization system for ship exhaust gas treatment

Abstract

The present invention discloses a desulfurization tower for treating ship exhaust gas, comprising a tower body, an air inlet, an air outlet and a seawater inlet are arranged on the tower body, at least one set of flue gas cyclone device and a spray device are arranged in the tower body, the air inlet is connected to the flue gas distribution device, the flue gas cyclone device is arranged above the flue gas distribution device, the spray device is arranged above the flue gas cyclone device, and the spray device is connected to the seawater inlet. The present invention also discloses a desulfurization system, the present invention provides a multi-stage flue gas cyclone device and a spray device, the flue gas passes through the flue gas cyclone device, and forms a uniform flue gas flow that rotates and rises, thereby making the flue gas evenly distributed, and increasing the contact area and contact time with the seawater sprayed by the spray device, so that the desulfurization reaction is more sufficient. At the same time, it is ensured that most of the ash generated by the flue gas will be washed away at the same time, reducing the volume of the desulfurization tower and reducing the amount of seawater used, saving the installation space of the desulfurization tower.

Description

Technical Field

[0001] The invention belongs to the technical field of ship exhaust gas treatment, and in particular relates to a desulfurization tower and a desulfurization system for ship exhaust gas treatment. Background Art

[0002] Since ship diesel engines burn low-quality heavy oil, the pollutants in the exhaust gas released are complex and have a serious impact on the ecological environment. Seawater desulfurization is usually used at sea. The flue gas generated by combustion is first dedusted before the seawater desulfurization is operated. Generally, a high-efficiency fiber or electrostatic precipitator is used and installed upstream of the SO2 absorption tower. The dedusted flue gas enters the bottom of the SO2 absorption tower and flows in the opposite direction of the seawater from top to bottom, completing a cycle. The clean flue gas coming out of the absorption tower is generally reheated before being discharged to prevent corrosion and ensure sufficient lifting height. Absorbing SO 2 The remaining seawater flows to the seawater treatment plant by gravity, where it is mixed with the rest of the seawater and introduced with an appropriate amount of air. The desulfurization towers of current ship desulfurization devices are basically in the form of axial reactors. Due to the limitation of ship installation space, the equipment volume cannot be too large, and due to the limitations of liquid flooding and reaction time, the tower diameter and height cannot be too small, forming a contradiction. In order to ensure that no liquid flooding occurs and the sulfur oxide removal rate is required, only larger equipment can be used to meet the relevant requirements, but it is limited by the ship space. Summary of the invention

[0003] The technical problem solved by the present invention is to reduce the volume of a desulfurization tower, increase the desulfurization reaction time, and thus improve the desulfurization capacity of the desulfurization tower.

[0004] Technical solution: In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0005] A desulfurization tower for treating ship exhaust gas comprises a tower body, on which an air inlet, an air outlet and a seawater inlet are arranged, in which at least one group of flue gas cyclone devices and a spray device are arranged, the air inlet is connected to a flue gas distribution device, the flue gas cyclone device is arranged above the flue gas distribution device, the spray device is arranged above the flue gas cyclone device, and the spray device is connected to the seawater inlet.

[0006] Preferably, the smoke cyclone device comprises a plurality of coaxially arranged mounting tubes, a circumferentially distributed cyclone plate assembly is arranged between two adjacent mounting tubes, and the cyclone plate assembly is provided with at least two circles.

[0007] Preferably, the swirl plate combination comprises a plurality of swirl plates evenly distributed on a circumference, and the rotation direction of each swirl plate is consistent.

[0008] Preferably, the swirl plate is in the shape of a spiral surface, and the angle α between the tangent direction of the bottom end of the swirl plate and the horizontal direction is 50° to 75°.

[0009] Preferably, the outermost circle of mounting tubes is fixed on the inner wall of the tower body, and the innermost circle of mounting tubes is coaxial with the tower body.

[0010] Preferably, at least four swirl plates are provided in each circle, and the number of swirl plates in the outer circle is greater than that in the inner circle.

[0011] Preferably, the spray device comprises a centrally distributed spray pipe, on which a nozzle is arranged, and the inclination direction of the nozzle is opposite to the swirl direction of the swirl plate.

[0012] Preferably, the smoke distribution device comprises at least three smoke distribution boxes and smoke distribution pipes separately connected to the smoke distribution boxes, the smoke distribution pipes are all connected to the air inlet, are closed on all sides and the bottom of the smoke distribution box, and a perforated plate is arranged on the upper end surface.

[0013] The desulfurization system using the above-mentioned desulfurization tower for ship exhaust treatment includes a seawater tank, a seawater pump unit, a desulfurization tower, a gray water discharge pipe and a purified exhaust gas discharge device. One end of the seawater pump unit is connected to the seawater tank, and the other end is connected to the seawater inlet of the desulfurization tower. The gray water discharge pipe is connected to the bottom of the desulfurization tower. The purified exhaust gas discharge device includes an exhaust fan and a chimney connected to the outlet at the top of the desulfurization tower.

[0014] Preferably, a water quality analysis unit is provided on the grey water discharge pipe, and an exhaust gas analyzer is provided between the exhaust fan and the chimney.

[0015] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0016] The present invention provides a multi-stage flue gas cyclone device and a spray device. After the flue gas passes through the flue gas cyclone device, it forms a uniform flue gas flow that rotates and rises, thereby making the flue gas evenly distributed and increasing the contact area and contact time with the seawater sprayed by the spray device, so that the desulfurization reaction is more complete. At the same time, it ensures that most of the ash generated by the flue gas will be washed away at the same time, reducing the volume of the desulfurization tower and the amount of seawater used, saving the installation space of the desulfurization tower. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the structure of a desulfurization tower for ship exhaust treatment;

[0018] Figure 2 It is a schematic diagram of the structure of a flue gas cyclone device of a desulfurization tower for ship exhaust treatment;

[0019] Figure 3This is a top view of the flue gas cyclone device of the desulfurization tower for ship exhaust treatment;

[0020] Figure 4 It is a schematic diagram of the structure of the flue gas distribution device of the desulfurization tower for ship exhaust gas treatment;

[0021] Figure 5 This is a top view of the flue gas distribution device of the desulfurization tower for ship exhaust treatment;

[0022] Figure 6 It is a schematic diagram of the structure of a desulfurization tower spray device for ship exhaust gas treatment. DETAILED DESCRIPTION

[0023] The present invention is further illustrated below in conjunction with specific examples. The examples are implemented based on the technical solutions of the present invention. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0024] The desulfurization tower for ship exhaust treatment of this embodiment includes a tower body 1, an air inlet 2 is arranged at the lower end of the tower body 1, the air inlet 2 is connected to the exhaust gas discharge port of the main engine and auxiliary engine of the ship, an air outlet 3 is arranged at the upper end of the tower body, a plurality of seawater inlets 4 are arranged on the side of the tower body, at least one group of flue gas cyclone device 5 and spray device 6 are arranged in the tower body 1, the air inlet 2 is connected to the flue gas distribution device 7, the flue gas cyclone device 5 is arranged above the flue gas distribution device 7, the spray device 6 is arranged above the flue gas cyclone device 5, and the spray device 6 is connected to the seawater inlet 4.

[0025] The smoke cyclone device 5 includes a plurality of coaxially arranged mounting tubes 51, and a cyclone plate assembly distributed around the circumference is arranged between two adjacent mounting tubes 51. The cyclone plate assembly is provided with at least two circles, and three circles are provided in this embodiment. The cyclone plate 52 assembly includes a plurality of cyclone plates 52 evenly distributed on the circumference, and each cyclone plate 52 rotates in the same direction. The cyclone plate 52 is in the shape of a spiral surface, similar to a fan blade, and the angle α between the tangent direction of the bottom end of the cyclone plate 52 and the horizontal direction is 50° to 80°, preferably 65°.

[0026] The outermost ring of mounting tubes 51 is fixed to the inner wall of the tower body 1 by bolts or welding, and the innermost ring of mounting tubes 51 is coaxial with the tower body 1. The mounting tubes are connected by swirl plates 52. The innermost ring of mounting tubes 51 may or may not be provided with a guide plate, which is determined according to the internal size of the desulfurization tower.

[0027] At least four swirl plates 52 are provided in each circle, and the number of swirl plates 52 in the outer circle is greater than that in the inner circle. In this embodiment, no swirl plates 52 are provided in the innermost circle of the mounting tube 51, the innermost circle of swirl plates is combined with four swirl plates 52, the middle circle of swirl plates is combined with six swirl plates 52, the outermost circle of swirl plates is combined with ten swirl plates, and the swirl plates of two adjacent circles are arranged alternately. After the flue gas passes through the flue gas swirl device, a uniform flue gas flow that is rotating and rising is formed, thereby making the flue gas evenly distributed, and increasing the contact area and contact time with the seawater sprayed by the spray device, so that the desulfurization reaction is more sufficient.

[0028] The spray device 6 includes a spray pipe 61 distributed in the center of a circle, and a nozzle 62 is arranged on the spray pipe 61. In order to further increase the contact area between seawater and flue gas, the inclination direction of the nozzle 62 is opposite to the swirl direction of the swirl plate 52, so that the two can contact each other in the fastest time, ensuring that the flue gas and washing water inside the desulfurization tower can have the longest reaction time and the most efficient reaction result, and ensuring that most of the ash generated by the flue gas can be washed away at the same time.

[0029] In order to make the flue gas entering the tower body from the air inlet enter the smoke cyclone device 5 evenly, the present invention provides a smoke distribution device, the smoke distribution device 7 includes at least three smoke distribution boxes 71 and smoke distribution pipes 72 separately connected to the smoke distribution boxes 71, the smoke distribution pipes 72 are all connected to the air inlet 2, and are closed on all sides and the bottom of the smoke distribution box 71, and a perforated plate 73 is provided on the upper end surface, and the smoke distribution pipes 72 are connected to the bottom of the smoke distribution box 71.

[0030] The present invention also discloses a desulfurization system using the above-mentioned desulfurization tower for ship exhaust treatment, comprising a seawater tank 8, a seawater pump unit 9, a desulfurization tower, a gray water discharge pipe 10 and a purified waste gas discharge device, wherein one end of the seawater pump unit 9 is connected to the seawater tank 8, a pre-pump filter is arranged at the front end of the seawater pump unit 9, and the other end is connected to the seawater inlet 4 of the desulfurization tower, the gray water discharge pipe 10 is connected to the bottom of the desulfurization tower, and the purified waste gas discharge device comprises an exhaust fan 11 and a chimney 12 connected to the gas outlet 3 at the top of the desulfurization tower.

[0031] The substandard liquid mixture after treatment in the desulfurization tower is discharged through the gray water discharge device. A water quality analysis unit 13 is provided on the gray water discharge pipe 10. The water quality analysis unit 13 mainly analyzes the pH value, turbidity, and polycyclic aromatic hydrocarbons (PAH) content of the discharged seawater. An exhaust gas analyzer 14 is provided between the exhaust fan 11 and the chimney 12 to detect the pollutant content of the purified gas, mainly the content of sulfur oxides and nitrogen oxides, to ensure that the purified gas discharged is up to standard. The two achieve the degree of purification of the gas and liquid discharged from the ship together.

[0032] Seawater is extracted from the seawater tank by two seawater pumps and passes through the pre-pump filter and necessary regulating butterfly valves (the pressure gauges before and after the pump show the normal working pressure of the seawater pump) to reach the upper space of the desulfurization tower. The seawater is mixed with the exhaust gas discharged by the main engine / auxiliary engine through the lower space of the desulfurization tower to form a convection mixing vortex treatment, so that clean air is discharged into the atmosphere from the upper pipe of the tower body, and the liquid mixture that does not meet the standards is discharged to the corresponding collection cabinet through the gray water discharge pipeline below, and the clean water is discharged to the ship, reducing the volume of the desulfurization tower and the amount of seawater used.

[0033] When the ship uses low-sulfur fuel oil, the present invention uses ordinary seawater to desulfurize the low-sulfur fuel oil after combustion. The ordinary seawater desulfurization method uses the natural alkaline components of seawater to neutralize the acidic gas components in the exhaust gas, thereby achieving the purpose of removing harmful gas components. However, ordinary seawater is not effective in treating high-sulfur fuel exhaust gas, because seawater has low solubility and adsorption capacity for SO2 and NO, especially for NO that is difficult to dissolve in water. When the ship uses high-sulfur fuel oil, the present invention uses a modified seawater method for desulfurization. First, an electrocatalytic method is used to modify natural seawater, change the pH of seawater, and enhance the seawater's ability to remove harmful components in exhaust gas. For example, seawater is electrolyzed to generate an alkaline sodium hydroxide solution. Compared with direct seawater washing, the use of sodium hydroxide solution as a detergent to purify the exhaust gas has a better effect.

[0034] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A desulfurization tower for ship exhaust treatment, Features: The tower body (1) comprises an air inlet (2), an air outlet (3) and a seawater inlet (4) arranged on the tower body (1); at least one set of a smoke cyclone device (5) and a spray device (6) are arranged in the tower body (1); the air inlet (2) is connected to a smoke distribution device (7); the smoke cyclone device (5) is arranged above the smoke distribution device (7); the spray device (6) is arranged above the smoke cyclone device (5); and the spray device (6) is connected to the seawater inlet (4); The smoke cyclone device (5) comprises a plurality of coaxially arranged mounting tubes (51), a circumferentially distributed cyclone plate assembly is arranged between two adjacent mounting tubes (51), and the cyclone plate assembly is provided with at least two circles; The swirl plate (52) combination comprises a plurality of swirl plates (52) evenly distributed on a circumference, and the rotation direction of each swirl plate (52) is consistent; the swirl plates (52) are in the shape of a spiral surface, and the angle α between the tangent direction of the bottom end of the swirl plate (52) and the horizontal direction is 50° to 75°; at least four swirl plates (52) are provided in each circle, and the number of swirl plates (52) in the outer circle is greater than the number of swirl plates (52) in the inner circle; the outermost circle mounting tube (51) is fixed on the inner wall of the tower body (1), and the innermost circle mounting tube (51) is coaxial with the tower body (1); The spray device (6) comprises a centrally distributed spray pipe (61), a nozzle (62) being arranged on the spray pipe (61), and the inclination direction of the nozzle (62) being opposite to the swirl direction of the swirl plate (52); The smoke distribution device (7) comprises at least three smoke distribution boxes (71) and smoke distribution pipes (72) separately connected to the smoke distribution boxes (71), wherein the smoke distribution pipes (72) are all connected to the air inlet (2), and the smoke distribution box (71) is closed on all sides and at the bottom, and a perforated plate (73) is provided on the upper end surface.

2. A desulfurization system using the desulfurization tower for ship exhaust treatment according to claim 1, Features: It comprises a seawater tank (8), a seawater pump unit (9), a desulfurization tower, a grey water discharge pipe (10) and a purified waste gas discharge device, wherein one end of the seawater pump unit (9) is connected to the seawater tank (8) and the other end is connected to a seawater inlet (4) of the desulfurization tower, the grey water discharge pipe (10) is connected to the bottom of the desulfurization tower, and the purified waste gas discharge device comprises an exhaust fan (11) and a chimney (12) connected to an outlet (3) at the top of the desulfurization tower; When ships use low-sulfur fuel oil, ordinary seawater is used for desulfurization after the low-sulfur fuel oil is burned. The ordinary seawater desulfurization method uses the natural alkaline components of seawater to neutralize the acidic gas components in the exhaust gas, thereby achieving the purpose of removing harmful gas components; when ships use high-sulfur fuel oil, the modified seawater method is used for desulfurization. First, the natural seawater is modified by an electrocatalytic method to change the pH of the seawater and enhance the seawater's ability to remove harmful components in the exhaust gas; the seawater is electrolyzed to generate an alkaline sodium hydroxide solution, and the sodium hydroxide solution is used as a detergent to purify the exhaust gas.

3. A desulfurization system using a desulfurization tower for ship exhaust treatment according to claim 2, Features: A water quality analysis unit (13) is provided on the grey water discharge pipe (10), and an exhaust gas analyzer (14) is provided between the exhaust fan (11) and the chimney (12).

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