CN216837396U - Desulfurization waste liquid treatment system for ship - Google Patents

Abstract

The utility model provides a desulfurization waste liquid treatment system for boats and ships, include: the mixing unit can receive the desulfurization waste liquid and an additive and mix the desulfurization waste liquid and the additive into low-concentration slag liquid, wherein the additive comprises a coagulant, a neutralizer and/or a heavy metal remover; and the solid-liquid separation unit is connected with the mixing unit, can separate low-concentration slag liquid into deslagging liquid and high-concentration slag liquid, and can discharge the deslagging liquid and the high-concentration slag liquid to the ocean and a designated collection area respectively. The utility model provides a pair of a desulfurization waste liquid processing system for boats and ships helps to solve the desulfurization waste liquid and is polluted, destroy the marine problem after being discharged, specifically is to avoid or reduced harmful substance such as suspended particle (taking aromatic compound as the owner), heavy metal ion, acid and/or alkali to the pollution and destruction of ocean.

Description

Desulfurization waste liquid treatment system for ship

Technical Field

The utility model belongs to the technical field of boats and ships, concretely relates to desulfurization waste liquid treatment system for boats and ships.

Background

In world freight transportation, ocean transportation occupies a large proportion. The ocean cargo transportation has the characteristics of large traffic capacity, large transportation volume, low transportation cost, strong adaptability to cargos, low speed, high risk and the like. At present, more than two thirds of the total transportation volume of international trade and 90% of the total transportation volume of goods at import and export in China are transported by ocean. In the marine transportation process, pollution and harm of pollutants discharged by ships to the atmospheric environment and the marine environment are becoming serious. The tail gas discharged by the combustion of the marine diesel engine mainly comprises sulfur dioxide and nitrogen oxide, and according to statistical data, the annual sulfur dioxide and nitrogen oxide discharged by the marine tail gas respectively account for about 13 percent and 14 percent of the total global emission. Therefore, the International Maritime Organization (IMO) made a decision to implement a global upper limit of 0.50 wt% for the sulfur content of marine fuels by the year 2020.

At present, the following three treatment measures are mainly taken for preventing the ship tail gas pollution: low sulfur content fuels are used, Liquefied Natural Gas (LNG) is used as an alternative fuel, or approved marine exhaust gas desulfurization techniques are used. Among them, the ship exhaust gas desulfurization technology is the most widely used technology at present, but a desulfurization waste liquid is generated in the exhaust gas desulfurization process, and the desulfurization waste liquid contains harmful substances such as suspended particles (main component aromatic compounds), heavy metal ions, acids and/or alkalis, and the pollution and damage to the marine environment can be caused after the desulfurization waste liquid is discharged to the sea.

SUMMERY OF THE UTILITY MODEL

In order to solve all or part of the above problems, the present invention provides a desulfurization waste liquid treatment system for ships, which is used to solve the problem that the desulfurization waste liquid pollutes and destroys the sea after being discharged, and particularly, to avoid or reduce the pollution and destruction of harmful substances such as suspended particles (mainly aromatic compounds), heavy metal ions, acids and/or alkalis to the sea.

The utility model provides a desulfurization waste liquid treatment system for boats and ships, include: the mixing unit can receive the desulfurization waste liquid and an additive and mix the desulfurization waste liquid and the additive into low-concentration slag liquid, wherein the additive comprises a coagulant, a neutralizer and/or a heavy metal removal agent; and the solid-liquid separation unit is connected with the mixing unit, can separate the low-concentration slag liquid into a deslagging liquid and a high-concentration slag liquid, and can discharge the deslagging liquid and the high-concentration slag liquid to the sea and a designated collection area respectively.

Further, the solid-liquid separation unit comprises a first-stage solid-liquid separation device for separating the low-concentration slag liquid into medium-concentration slag liquid and deslagging liquid and a second-stage solid-liquid separation device capable of separating the medium-concentration slag liquid into the high-concentration slag liquid and deslagging liquid, a low-concentration slag liquid inlet of the first-stage solid-liquid separation device is connected with a low-concentration slag liquid outlet of the mixing unit, a medium-concentration slag liquid outlet of the first-stage solid-liquid separation device is connected with a medium-concentration slag liquid inlet of the second-stage solid-liquid separation device, a deslagging liquid outlet of the first-stage solid-liquid separation device is used for discharging the deslagging liquid, a high-concentration slag liquid outlet of the second-stage solid-liquid separation device is used for discharging the high-concentration slag liquid, and a deslagging liquid outlet of the second-liquid separation device is also used for discharging the deslagging liquid.

Further, the secondary solid-liquid separation device comprises: the medium-concentration slag liquid inlet is arranged at the bottom end of the bottle of the shell; the high-concentration slag liquid outlet is arranged at the bottle mouth end of the shell; the bent pipe is inserted into the shell, the inlet of the bent pipe is positioned in the shell and faces to the medium-concentration slag liquid inlet of the shell, and the outlet of the bent pipe is positioned outside the shell and is used as a slag removal liquid outlet of the secondary solid-liquid separation device; the impeller is arranged in the bottom end of the bottle of the shell; the power source is arranged inside or outside the shell and is used for driving the impeller to rotate; wherein the power source is configured to drive the impeller to rotate and promote the medium-concentration slag liquid to generate vortex under the stirring of the impeller and perform solid-liquid separation, so that the separated high-concentration slag liquid and the separated deslagged liquid are discharged from the high-concentration slag liquid outlet and the deslagged liquid outlet respectively.

Further, the second-stage solid-liquid separation device further comprises a flow guide piece arranged on one side, close to the medium-concentration slag liquid inlet of the shell, of the impeller, and the cross section area of the flow guide piece is gradually increased along the flowing direction of the medium-concentration slag liquid.

Further, the impeller comprises a rotating shaft and blades arranged on the rotating shaft, wherein the number of the blades is 10-24, and an included angle between each blade and a radial plane of the rotating shaft is 8-24 degrees.

Further, the first-stage solid-liquid separation device is a gravity type solid-liquid separator, and the second-stage solid-liquid separation device is a centrifugal type solid-liquid separator.

Further, the solid-liquid separation unit also comprises a first conveying pump arranged between the first-stage solid-liquid separation device and the second-stage solid-liquid separation device.

Further, desulfurization waste liquid treatment system still includes: the first feeding unit comprises a first storage tank capable of supplementing the neutralizing agent into the mixing unit, and a second delivery pump and a first throttling valve which are arranged between the first storage tank and the mixing unit; the second charging unit comprises a second storage tank which can supplement the coagulant into the mixing unit, and a third delivery pump and a second throttling valve which are arranged between the second storage tank and the mixing unit; and/or the third feeding unit comprises a third storage tank for supplementing the heavy metal removal agent into the mixing unit, and a fourth delivery pump and a third throttling valve which are arranged between the third storage tank and the mixing unit.

Further, the desulfurization waste liquid treatment system also comprises a collection container which is connected with the high-concentration slag liquid and is used for collecting the high-concentration slag liquid.

Further, the neutralizing agent is a sodium hydroxide solution, the coagulant is a polyaluminium chloride solution or a polyferric sulfate solution, and the heavy metal remover is an organic sulfur heavy metal remover.

According to the technical scheme, the desulfurization waste liquid treatment system for the ship mixes the desulfurization waste liquid (containing seawater) and the additive into the low-concentration slag liquid through the mixing unit, and as the additive contains the coagulant, the neutralizer and/or the heavy metal remover and the like, therefore, when the desulfurization waste liquid is changed into low-concentration slag liquid, suspended particles (mainly aromatic compounds) in the desulfurization waste liquid can be flocculated and coagulated to form coagulants, heavy metal ions can be removed, excessive acid or alkali can be neutralized by a neutralizing agent, then separating the low-concentration slag liquid containing the condensate into high-concentration slag liquid and desludging liquid through a solid-liquid separation unit, wherein the large, less polluting detritus liquid is discharged to the ocean, while the small, harmful and high concentration detritus liquid containing large amounts of condensate is discharged to a collection area for secondary treatment or utilization. In this way, the desulfurization waste liquid treatment system can solve the problem that the desulfurization waste liquid pollutes and destroys the sea after being discharged, and particularly, the pollution and destruction of harmful substances such as suspended particles (mainly aromatic compounds), heavy metal ions, acid and/or alkali and the like to the sea can be avoided or reduced. In addition, the desulfurization waste liquid treatment system is simple in structure, easy to assemble, safe and reliable to use, high in purification efficiency and convenient to implement, popularize and apply.

Drawings

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the figure:

FIG. 1 is a functional block diagram of a desulfurization waste liquid treatment system for a ship according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a second-stage solid-liquid separation device of a desulfurization waste liquid treatment system for ships according to an embodiment of the present invention.

In the drawings, like parts are provided with like reference numerals. The figures are not drawn to scale.

Detailed Description

The present invention will be further explained with reference to the accompanying drawings. FIG. 1 is a structural frame of a desulfurization waste liquid treatment system for a ship according to an embodiment of the present invention; fig. 2 is a schematic structural diagram of a second-stage solid-liquid separation device of a desulfurization waste liquid treatment system for ships according to an embodiment of the present invention. As shown in fig. 1 and 2, an embodiment of the present invention includes at least one desulfurization waste liquid treatment system 100 for a ship. The desulfurization waste liquid treatment system 100 includes a mixing unit 10 and a solid-liquid separation unit 20. The mixing unit 10 can receive the desulfurization waste liquid and an additive, and mix the desulfurization waste liquid and the additive into low-concentration slag liquid, wherein the additive comprises a coagulant, a neutralizer and/or a heavy metal removal agent. In the using process, the existence and proportion of the coagulant, the neutralizer and the heavy metal remover are selected according to the harmful substance components and the content in the desulfurization waste liquid. In this example, the neutralizing agent is preferably a sodium hydroxide solution, the coagulant is preferably a polyaluminum chloride solution, and the heavy metal removal agent is preferably an organic sulfur-based heavy metal removal agent (also known as a 15% TMT solution). The solid-liquid separation unit 20 is connected to the mixing unit 10, and can separate the received low-concentration slag liquid into a deslagged liquid and a high-concentration slag liquid, and discharge the deslagged liquid and the high-concentration slag liquid to the ocean and a designated collection area, respectively.

According to the embodiment of the utility model, desulfurization waste liquid processing system 100 mixes desulfurization waste liquid (including sea water) and additive through mixing unit 10 for low concentration slag liquid, because the additive has contained coagulant, neutralizer and/or heavy metal desorption agent etc., so when desulfurization waste liquid becomes low concentration slag liquid, suspended particle (mainly with aromatic compound) in it can take place flocculation and coagulation and form the coagulation body, heavy metal ion can be got rid of, excessive acid or alkali can be neutralized by the neutralizer, then the low concentration slag liquid that contains the coagulation body is separated into high concentration slag liquid and desludging liquid through solid-liquid separation unit 20, wherein the volume is big, the desludging liquid that pollutes little is discharged to the ocean, and the volume is few, harmful and the high concentration slag liquid that contains a large amount of coagulation body is discharged the collection region, with treating secondary treatment or utilizing. In this way, the desulfurization waste liquid treatment system 100 can solve the problem that the desulfurization waste liquid pollutes and damages the sea after being discharged, and particularly, the pollution and damage of harmful substances such as suspended particles (mainly aromatic compounds), heavy metal ions, acids and/or alkalis to the sea can be avoided or reduced.

The solid-liquid separation unit 20 may be selected as one-stage or multi-stage solid-liquid separation device or a combination of devices. However, in the present embodiment, in order to achieve the dual advantages of low cost and good separation effect, the solid-liquid separation unit 20 may include a primary solid-liquid separation device 21 capable of separating low-concentration slag liquid into medium-concentration slag liquid and deslagging liquid, and a secondary solid-liquid separation device 23 capable of separating medium-concentration slag liquid into high-concentration slag liquid and deslagging liquid. Wherein, the low concentration slag liquid inlet of the first solid-liquid separation device 21 is connected with the low concentration slag liquid outlet of the mixing unit 10, the medium concentration slag liquid outlet of the first solid-liquid separation device 21 is connected with the medium concentration slag liquid inlet of the second solid-liquid separation device 23, the deslagging liquid outlet of the first solid-liquid separation device 21 is used for discharging deslagging liquid, the high concentration slag liquid outlet 233 of the second solid-liquid separation device 23 is used for discharging high concentration slag liquid, and the deslagging liquid outlet of the second solid-liquid separation device 23 is also used for discharging deslagging liquid. Preferably, the desludging liquid outlet of the stage solid-liquid separation device 21 and the desludging liquid outlet of the stage solid-liquid separation device 23 can discharge the desludging liquid into the ocean directly or with the help of a discharge pipeline.

The first-stage solid-liquid separation device 21 and the second-stage solid-liquid separation device 23 may be selected from a filtration type solid-liquid separator, a gravity type solid-liquid separator, a centrifugal type solid-liquid separator, and the like. However, in the present embodiment, the first-stage solid-liquid separation device 21 is preferably a gravity type solid-liquid separator, and the second-stage solid-liquid separation device 23 is preferably a centrifugal type solid-liquid separator. The gravity type solid-liquid separator is used firstly, the preliminary separation can be completed under the condition of minimum consumption, the total amount of slag liquid flowing into the secondary solid-liquid separation device 23 is reduced, the energy consumption of the secondary solid-liquid separation device 23 is reduced, and the centrifugal solid-liquid separator is selected by the secondary solid-liquid separation device 23 to complete the solid-liquid separation with higher efficiency. As shown in fig. 2, the two-stage solid-liquid separation device 23 is a novel and efficient centrifugal solid-liquid separator, and includes a bottle-shaped housing 231, a medium-concentration slag-liquid inlet 232, a high-concentration slag-liquid outlet 233, an elbow 234, an impeller 235 and a power source. Wherein, the medium concentration slag liquid inlet 232 is arranged at the bottom end of the bottle of the shell 231, and the high concentration slag liquid outlet 233 is arranged at the bottle opening end of the shell 231. The elbow 234 is inserted into the housing 231, and has an inlet located in the housing 231 and facing the medium-concentration slag liquid inlet 232 of the housing 231, and an outlet located outside the housing 231 and serving as a slag-removed liquid outlet of the secondary solid-liquid separation device 23. An impeller 235 is provided in the bottom end of the housing 231. The power source is disposed inside or outside the housing 231 and is used to drive the impeller 235 to rotate, and is preferably an electric motor. Wherein, the power source is configured to drive the impeller 235 to rotate and promote the medium-concentration slag liquid to generate vortex under the stirring of the impeller 235 and carry out solid-liquid separation, so that the separated high-concentration slag liquid bypasses the elbow 234 after passing through the impeller 235 and then is discharged through the high-concentration slag liquid outlet 233, and the desludging liquid enters the elbow 234 after passing through the impeller 235 and then is discharged through the desludging liquid outlet.

A large number of tests prove that when the inlet of the elbow 234 is preferably arranged at the central position of the vortex generated by the impeller 235, the distance from the impeller 235 is preferably 2-10 times that of the impeller 235, and the diameter of the inlet is preferably 0.05-0.5 times that of the impeller 235, the deslagging liquid collected by the elbow 234 contains less harmful substances, and the separation effect of the solid-liquid separation unit 20 is further improved.

In this embodiment, the secondary solid-liquid separation device 23 further includes a flow guide member 236 disposed on the side of the impeller 235 close to the medium-concentration slag liquid inlet 232 of the housing 231, and the cross-sectional area of the flow guide member 236 gradually increases along the flowing direction of the medium-concentration slag liquid. The flow guiding element 236 can send the inflowing medium-concentration slag liquid to the outer side of the impeller 235 with higher linear velocity so as to avoid the slag liquid flowing to the central part with lower linear velocity. The high-concentration slag liquid and the high-concentration deslag liquid are separated under the combined action of density difference and centrifugal force, and the separation effect is improved. The flow guide 236 may alternatively be a semi-ellipsoid, semi-cone or semi-sphere, etc. A large number of tests prove that when the flow guide member 236 is a hemisphere and the diameter of the flow guide member 236 is 0.05-0.35 times of the overall diameter of the impeller 235, the flow guide member has a high flow guide effect, and further the separation effect is improved.

In the present embodiment, the impeller 235 includes a rotating shaft and blades disposed on the rotating shaft, wherein the number of the blades is preferably 10-24, and the inclination angle of the blades to the radial plane of the rotating shaft is preferably 8-42 °. Preferably, the vanes have a projected shape in the radial plane that is preferably trapezoidal with the longer base having a width of about 0.2 to 2 times the diameter of the impeller 235 and the shorter base having a width of about 0.1 to 1 times the longer base. A large number of tests prove that when the blades meet the conditions, the secondary solid-liquid separation device 23 has higher separation efficiency.

In the present embodiment, the solid-liquid separation unit 20 further includes a first transfer pump 22 provided between the primary solid-liquid separation device 21 and the secondary solid-liquid separation device 23. The first conveying pump 22 can convey the medium-concentration slag liquid generated by the first-stage solid-liquid separation device 21 into the second-stage solid-liquid separation device 23 to provide power for the medium-concentration slag liquid to flow to the second-stage solid-liquid separation device 23.

In this embodiment, the desulfurization waste liquid treatment system 100 further includes a first feeding unit 40, a second feeding unit 50, and/or a third feeding unit 60. Wherein the first feeding unit 40 comprises a first storage tank capable of replenishing the neutralizing agent into the mixing unit 10, and a second delivery pump and a first throttling valve provided between the first storage tank and the mixing unit 10. The second charging unit 50 includes a second storage tank capable of replenishing coagulant into the mixing unit 10, and a third delivery pump and a second throttle valve provided between the second storage tank and the mixing unit 10. The third feeding unit 60 includes a third storage tank for replenishing the heavy metal removal agent into the mixing unit 10, and a fourth transfer pump and a third throttle valve provided between the third storage tank and the mixing unit 10. The additives required by the mixing unit 10 can be stored by the first feeding unit 40, the second feeding unit 50 and/or the third feeding unit 60, and the amount of the additives can be controlled by the first throttling valve, the second throttling valve and/or the third throttling valve, so that the mixing effect of the mixing unit 10 can be adjusted, the content of harmful components in discharged desludging liquid can be reduced, and the pollution and damage to the marine environment can be reduced.

In this embodiment, the desulfurization waste liquid treatment system 100 further includes a collection container 30 connected to and for collecting the high concentration slag liquid. The collecting container 30 is used for collecting high-concentration slag liquid, and is beneficial to reducing pollution and damage to the marine environment caused by leakage and outflow of the high-concentration slag liquid. Collecting container 30 can be selected as the metal tank body, and the internal anticorrosive coating that is equipped with of metal tank is favorable to increase of service life.

Experiments prove that the concentration of suspended particles in the desulfurization waste liquid is generally 0.001-0.006%, and after passing through the desulfurization waste liquid treatment system 100, the concentration of suspended particles in the high-concentration slag liquid is 10-45%. For example, a diesel engine model for a cruise ship generator set

9L46D, power 9.8MW, design adopts 3.5% sulfur content marine heavy fuel oil (abbreviated as HFO in English), is equipped with ship exhaust gas desulfurization device and desulfurization waste liquid processing system 100, and ship exhaust gas desulfurization device uses sea water as detergent, and the sea water consumption is 80m 3/MW. After sailing, the ship waste gas desulfurization device and the desulfurization waste liquid treatment system 100 are started, when the ship waste gas desulfurization device and the desulfurization waste liquid treatment system operate at full load, the amount of washing seawater is 784m3/h, the desulfurization waste liquid in the ship waste gas desulfurization device is extracted at the speed of 5m 3/h-25 m3/h and is sent into the desulfurization waste liquid treatment system 100, and finally the concentration of suspended particles in the high-concentration slag liquid is 15-30%. Adopt desulfurization waste liquid processing system 100 can simplify present complicated effluent treatment plant, provides technical support for the suitability of boats and ships desulfurization ring-opening mode, and its simple structure, assembly are easy moreover, use safe and reliable and purification efficiency is high, the implementation of being convenient for popularize and apply.

To sum up, the utility model provides a desulfurization waste liquid processing system 100 for boats and ships can reduce the pollution and the destruction that harmful component such as heavy metal, suspended particles (use aromatic compound as the main) caused marine environment in the desulfurization waste liquid that the boats and ships waste gas desulfurization in-process produced. Furthermore, the utility model provides a desulfurization waste liquid treatment system 100 for boats and ships's simple structure, the effect is obvious, low in manufacturing cost, very facilitate promotion and implementation.

In the description of the present application, it is to be understood that the terms "center", "length", "width", "thickness", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", and the like, are used in the orientation or positional relationship indicated in the drawings, merely for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be considered as limiting the present invention.

Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

In this application, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can include, for example, fixed connections, removable connections, or integral parts; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

The above description is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily make changes or variations within the technical scope of the present invention, and such changes or variations should be covered by the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims. The technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. The present invention is not intended to be limited to the particular embodiments disclosed herein, but rather to include all embodiments falling within the scope of the appended claims.

Claims (9)

1. A desulfurization waste liquid treatment system for a ship, characterized by comprising:

the mixing unit can receive the desulfurization waste liquid and the additive and mix the desulfurization waste liquid and the additive into low-concentration slag liquid;

the solid-liquid separation unit is connected with the mixing unit, can separate the low-concentration slag liquid into a deslagging liquid and a high-concentration slag liquid, and also respectively discharges the deslagging liquid and the high-concentration slag liquid to the sea and a designated collection area;

the solid-liquid separation unit comprises a first-stage solid-liquid separation device and a second-stage solid-liquid separation device, wherein the first-stage solid-liquid separation device is used for separating the low-concentration slag liquid into medium-concentration slag liquid and deslagging liquid, the second-stage solid-liquid separation device is used for separating the medium-concentration slag liquid into the high-concentration slag liquid and deslagging liquid, a low-concentration slag liquid inlet of the first-stage solid-liquid separation device is connected with a low-concentration slag liquid outlet of the mixing unit, a medium-concentration slag liquid outlet of the first-stage solid-liquid separation device is connected with a medium-concentration slag liquid inlet of the second-stage solid-liquid separation device, a deslagging liquid outlet of the first-stage solid-liquid separation device is used for discharging the deslagging liquid, and a high-concentration slag liquid outlet of the second-solid separation device is also used for discharging the deslagging liquid.

2. The desulfurization waste liquid treatment system according to claim 1, wherein the secondary solid-liquid separation device includes:

a shell body, a plurality of first connecting rods and a plurality of second connecting rods,

the medium-concentration slag liquid inlet is arranged at the bottom end of the shell;

the high-concentration slag liquid outlet is arranged at the end opposite to the bottom end of the shell;

the elbow pipe is inserted into the shell, the inlet of the elbow pipe is positioned in the shell and faces to the medium-concentration slag liquid inlet of the shell, and the outlet of the elbow pipe is positioned outside the shell and serves as a slag removing liquid outlet of the secondary solid-liquid separation device;

an impeller disposed within a bottom end of the housing;

the power source is arranged inside or outside the shell and is used for driving the impeller to rotate;

wherein the power source is configured to drive the impeller to rotate and promote the medium-concentration slag liquid to generate vortex under the stirring of the impeller and perform solid-liquid separation, so that the separated high-concentration slag liquid and the separated deslagged liquid are discharged from the high-concentration slag liquid outlet and the deslagged liquid outlet respectively.

3. The desulfurization waste liquid treatment system according to claim 2, wherein the secondary solid-liquid separation device further comprises a flow guide member provided on a side of the impeller close to the medium-concentration slag liquid inlet of the housing, and a cross-sectional area of the flow guide member gradually increases along a flow direction of the medium-concentration slag liquid.

4. The desulfurization waste liquid treatment system of claim 2, wherein the impeller comprises a rotating shaft and blades arranged on the rotating shaft, wherein the number of the blades is 10-24, and an included angle between each blade and a radial plane of the rotating shaft is 8-24 °.

5. The desulfurization waste liquid treatment system according to claim 1, wherein the primary solid-liquid separation device is a gravity solid-liquid separator, and the secondary solid-liquid separation device is a centrifugal solid-liquid separator.

6. The desulfurization waste liquid treatment system according to claim 1, wherein the solid-liquid separation unit further comprises a first transfer pump provided between the primary solid-liquid separation device and the secondary solid-liquid separation device.

7. The desulfurization waste liquid treatment system according to any one of claims 1 to 6, further comprising:

the first feeding unit comprises a first storage tank capable of supplementing a neutralizing agent into the mixing unit, and a second delivery pump and a first throttling valve which are arranged between the first storage tank and the mixing unit;

the second charging unit comprises a second storage tank, a third delivery pump and a second throttling valve, wherein the second storage tank can be used for supplementing a coagulant into the mixing unit, and the third delivery pump and the second throttling valve are arranged between the second storage tank and the mixing unit; and/or

And the third feeding unit comprises a third storage tank for supplementing the heavy metal removal agent into the mixing unit, and a fourth delivery pump and a third throttling valve which are arranged between the third storage tank and the mixing unit.

8. The desulfurization waste liquid treatment system according to any one of claims 1 to 6, further comprising a collection container connected to and for collecting the high concentration slag liquid.

9. The desulfurization waste liquid treatment system according to claim 7, wherein the neutralizing agent is a sodium hydroxide solution, the coagulant is a polyaluminum chloride solution or a polyferric sulfate solution, and the heavy metal removal agent is an organic sulfur heavy metal removal agent.

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