A coke oven flue gas desulfurization pulp preparation control method

Abstract

The present application belongs to the technical field of desulfurization pulping, and relates to a coke oven flue gas desulfurization pulping control method. A slurry distributor is connected to a pulping digestion tank, and the slurry distributor is arranged in parallel with a vibrating screen, so that the slurry discharge direction of the slurry distributor is parallel to the vibrating screen, the impact of the slurry on the vibrating screen is reduced, the width of the slurry discharge port is expanded through the slurry distributor, and the slurry is uniformly discharged onto the vibrating screen. The slurry distributor comprises a distributor shell and baffles. One end of the distributor shell is provided with a slurry inlet, and the other end is provided with a slurry discharge port. The slurry inlet is communicated with the pulping digestion tank through a slurry downpipe. The baffles are multiple and are arranged between the slurry inlet and the slurry discharge port. The baffles guide the slurry from the slurry inlet to the slurry discharge port. The present application guides the slurry through the slurry distributor, so that the slurry discharge direction is parallel to the vibrating screen and the width of the discharge port is expanded, the problem of impacting the vibrating screen during the lime slurry discharging process is solved, the splashing of the slurry is reduced, and the effect of the vibrating screen is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of desulfurization pulping, and relates to a coke oven flue gas desulfurization pulping control method. BACKGROUND

[0002] According to the Work Plan for Ultra-low Emission Transformation of Steel Enterprises, the ultra-low emission limit value of the coke oven chimney is that particulate matter is less than or equal to 10 mg / m 3 , SO2 is less than or equal to 30 mg / m 3 , and NO X is less than or equal to 150 mg / m 3 by the end of 2025. In order to meet the requirements of ultra-low emission of steel enterprises, the coke oven chimney exhaust gas must be treated by a desulfurization and denitrification device to meet the emission standard. The semi-dry SDA desulfurization process is usually selected for desulfurization and denitrification, but a series of problems occur in the pulping system during implementation.

[0003] 1. During the digestion process of the pulping digestion tank, the distance between the stirrer and the conical hopper at the bottom of the digestion tank is too large (> 500 mm), which causes the raw lime to accumulate in the conical hopper, resulting in poor digestion effect.

[0004] 2. After the digestion of the slurry is completed, the raw lime accumulated in the bottom conical hopper causes the discharge pipe to be blocked, which is difficult to dredge, and there is a certain safety risk of unreacted raw lime during the treatment process.

[0005] 3. When the lime slurry after the digestion reaction is discharged to the vibrating screen, the discharge port is at 90° to the vibrating screen, and the slurry splashes in all directions after impacting the vibrating screen, which not only causes environmental pollution but also reduces the operation effect of the vibrating screen.

[0006] 4. There is no throttling control valve during the discharging process of the lime slurry after the digestion reaction, and the discharging speed of the slurry is not limited, which causes the slurry to flow into the collection hopper along with the dregs, thereby polluting the ground environment. SUMMARY

[0007] Therefore, the purpose of the present application is to solve the above problems and provide a coke oven flue gas desulfurization pulping control method.

[0008] To achieve the above purpose, the present application provides the following technical scheme:

[0009] A coke oven flue gas desulfurization pulping control method, a slurry distributor is connected to the pulping digestion tank, the slurry distributor is arranged in parallel with the vibrating screen, so that the discharge direction of the slurry in the slurry distributor is parallel to the vibrating screen, reducing the impact of the slurry on the vibrating screen, and at the same time, the width of the slurry discharge port is expanded through the slurry distributor, so that the slurry is uniformly discharged onto the vibrating screen.

[0010] Further, the slurry distributor comprises a distributor shell, a baffle plate, one end of the distributor shell is provided with a slurry inlet, the other end is provided with a slurry outlet; the slurry inlet is communicated with the pulp digestion tank through a slurry pipe; the baffle plate is provided between the slurry inlet and the slurry outlet, and the baffle plate guides the slurry from the slurry inlet to the slurry outlet.

[0011] Further, the baffle plate is provided with a 60°-60° angle structure along the length direction, which buffers and reduces the speed of the slurry.

[0012] Further, the pulp digestion tank adopts double-layer agitators, and the distance between the lower agitator blade and the bottom plate of the pulp digestion tank is not greater than 200mm.

[0013] Further, the slurry pipe is arranged on the side wall of the pulp digestion tank and close to the bottom of the pulp digestion tank.

[0014] Further, the side wall of the pulp digestion tank is further provided with an overflow pipe, the overflow pipe is arranged above the slurry pipe and communicated with the slurry pipe.

[0015] Further, the overflow pipe is provided with an overflow valve, and one end of the slurry pipe close to the pulp digestion tank is provided with a slurry discharging valve.

[0016] Further, the slurry pipe is further connected with a cleaning pipe, and the cleaning pipe is provided with a cleaning valve.

[0017] Further, a manual butterfly valve is arranged at one end of the slurry pipe close to the slurry inlet, and the slurry flow is controlled through the manual butterfly valve.

[0018] The beneficial effects of the present application are as follows:

[0019] 1. The slurry distributor is installed between the pulp digestion tank and the vibrating screen, the slurry is guided by the slurry distributor, the slurry outlet direction is parallel to the vibrating screen, the width of the outlet is expanded, the slurry is uniformly discharged to at least 2 / 3 of the vibrating screen surface, the problem of impacting the vibrating screen during the lime slurry discharging process is solved, the splashing of the slurry is reduced, and the effect of the vibrating screen is improved.

[0020] 2. The distance between the agitator and the bottom of the digestion tank is reduced; the lime slurry discharge is changed to the side bottom position, the blockage of the discharge pipe caused by the accumulation of the conical hopper is avoided; the cleaning pipe is additionally arranged to solve the occasional blockage problem; the control valve is additionally arranged on the slurry pipe, the opening degree can be adjusted according to the on-site operation condition, the efficient and environmentally-friendly operation of the vibrating screen is ensured, the stable and efficient and environmentally-friendly operation of the pulp system is realized, and the necessary conditions for the stable and safe operation of the whole desulfurization and denitrification system are provided.

[0021] Additional advantages, objects, and features of the application will be apparent to those skilled in the art upon examination of the following detailed description, it being understood that each of the foregoing general statements are true of the particular embodiments of the application. The objects and other advantages of the application can be better understood and appreciated from the following detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to make the objects, technical solutions and advantages of the present application clearer, the preferred embodiments of the present application will be described in detail below with reference to the drawings, in which:

[0023] Fig. 1 A schematic diagram of a pulping system in the present application.

[0024] Fig. 2 A schematic diagram of a slurry distributor in the present application.

[0025] Legend: 1 - water supply pipe; 2 - upper and lower double-layer stirrer; 3 - lime pipe; 4 - pulping digestion tank; 5 - overflow pipe; 6 - slurry discharge valve; 7 - cleaning pipe; 8 - slurry discharge pipe; 9 - manual butterfly valve; 10 - slurry distributor; 11 - vibrating screen; 12 - screen mesh; 13 - residue discharge port; 14 - residue collecting hopper; 15 - lime slurry tank; 16 - slurry discharge pipe; 101 - distributor shell; 102 - baffle; 103 - fixing rib; 104 - slurry inlet; 105 - slurry discharge port. DETAILED DESCRIPTION

[0026] The present application is described below by way of specific embodiments, and those skilled in the art can easily understand other advantages and effects of the present application from the disclosure of the present specification. The present application can also be implemented or applied by different specific embodiments, and various modifications or changes can be made to the details in the present specification based on different views and applications without departing from the spirit of the present application. It should be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present application in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0027] The drawings are only used for exemplary illustration, and the representation is only a schematic diagram, not a physical diagram, and should not be understood as a limitation of the present application; in order to better illustrate the embodiments of the present application, some components in the drawings may be omitted, enlarged or reduced, and do not represent the actual size of the product; it can be understood by those skilled in the art that some known structures and their descriptions in the drawings may be omitted.

[0028] The same or similar reference numerals in the drawings of the embodiments of the present application correspond to the same or similar components; in the description of the present application, it is understood that if the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "front", "back", etc. are based on the orientations or positional relationships shown in the drawings, they are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the terms describing the positional relationships in the drawings are only used for exemplary illustration and cannot be understood as a limitation on the present application, for those skilled in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0029] Please refer to Figs. 1-2 For the pulp making system applying the coke oven flue gas desulfurization and pulp making control method in the present application, a pulp liquid distributor 10 is connected to the pulp making digestion tank 4, the pulp liquid distributor 10 is arranged in parallel with the vibrating screen 11, so that the pulp liquid discharge direction in the pulp liquid distributor 10 is parallel to the vibrating screen 11, reducing the impact of the pulp liquid on the vibrating screen 11, and at the same time, the width of the pulp liquid discharge port 105 is expanded through the pulp liquid distributor 10, so that the pulp liquid is uniformly discharged onto the vibrating screen 11. Among them, the pulp liquid distributor 10 includes a distributor shell 101 and a baffle plate 102; the distributor shell 101 is made of 6mm steel plate, the length of the distributor shell 101 is 500mm, the width is 600mm, the distance between the distributor bottom plate and the top plate is 80mm, the baffle plate 102 is installed between the bottom plate and the top plate, and the beginning and the end of the baffle plate 102 are both welded and fixed with a φ10 round steel as a fixing rib 103.

[0030] One end of the distributor shell 101 is provided with a pulp inlet 104, and the other end is provided with a pulp liquid discharge port 105; the pulp inlet 104 is communicated with the pulp making digestion tank 4 through the pulp downpipe 8; the baffle plate 102 is processed with a 2mm steel plate into a 60° angle structure in forward and reverse directions, which buffers and reduces the speed of the pulp liquid. Among them, the baffle plate 102 is multiple and is installed between the pulp inlet 104 and the pulp liquid discharge port 105, guiding the pulp liquid from the pulp inlet 104 to the pulp liquid discharge port 105.

[0031] The pulp making digestion tank 4 is installed with a water supplement tank and a lime pipeline 3 through a screw conveyor, the pulp making digestion tank 4 adopts an upper and lower double-layer agitator 2, and the distance between the lower agitator blade and the bottom plate of the pulp making digestion tank 4 is not greater than 200mm.

[0032] The pulp pipe 8 is arranged on the side wall of the pulp digestion tank 4 and close to the bottom of the pulp digestion tank 4. The overflow pipe 5 is arranged on the side wall of the pulp digestion tank 4 and above the pulp pipe 8 and communicates with the pulp pipe 8. The overflow valve is arranged on the overflow pipe 5, and the pulp discharge valve 6 is arranged on one end of the pulp pipe 8 close to the pulp digestion tank 4. The cleaning pipe 7 is connected to the pulp pipe 8 and the cleaning valve is arranged on the cleaning pipe 7 to flush in case of occasional blockage or poor flow. Meanwhile, the manual butterfly valve 9 is arranged on one end of the pulp pipe 8 close to the pulp inlet 104 to control the pulp flow.

[0033] The pulp distributor 10 is fixedly arranged on one side of the vibrating screen 11, the width of the pulp discharge outlet 105 can cover at least 2 / 3 of the screen surface of the screen 12, and the lower end of the vibrating screen 11 is provided with the pulp discharge pipe 16, the pulp enters the lime pulp tank 15 through the pulp discharge pipe 16, and the screened dregs enter the dreg collecting hopper 14 through the dreg discharge port 13.

[0034] During operation, when the liquid level of the lime pulp tank 15 is lower than 1200mm, the pulp preparation is started, the water is added to the pulp digestion tank 4 through the water supplement pipe 1 to 1000mm, the weight is calculated and set in advance, the raw lime is fed to the pulp digestion tank 4 through the screw scale, and the feeding of the raw lime is stopped when the set weight is reached or the temperature in the digestion tank is greater than 80℃. The digestion tank is digested for 450s under the action of the upper and lower double-layer mixers 2 (the digestion time can be appropriately prolonged or shortened according to the pulp condition). After the digestion reaction is completed, the pulp discharge valve 6 is opened to discharge the pulp, and the optimized pulp discharge speed, the pulp splashing condition and the pulp entrainment in the dregs are observed during the period, and the manual butterfly valve 9 is adjusted in time to control the pulp flow.

[0035] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application but not limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the purpose and scope of the present application, and all of them should be covered in the scope of the claims of the present application.

Claims

1. A method for controlling the desulfurization and pulping of coke oven flue gas, characterized in that: A slurry distributor is connected to the pulping and digestion tank. The slurry distributor is arranged parallel to the vibrating screen so that the slurry discharge direction in the slurry distributor is parallel to the vibrating screen, thereby reducing the impact of the slurry on the vibrating screen. At the same time, the slurry distributor expands the width of the slurry discharge outlet, so that the slurry is evenly discharged onto the vibrating screen. The slurry distributor includes a distributor housing and baffles. One end of the distributor housing has a slurry inlet, and the other end has a slurry outlet. The slurry inlet is connected to the pulping and digestion tank via a slurry drain pipe. Multiple baffles are spaced between the slurry inlet and the slurry outlet to guide the slurry from the inlet to the outlet. Each baffle has a 60° bend along its length to buffer and reduce the slurry velocity. The pulping and digestion tank uses a double-layer agitator, with the distance between the lower agitator blades and the bottom plate of the tank controlled to be no more than 200mm. The slurry drain pipe is located on the side wall of the pulping and digestion tank, near the bottom. An overflow pipe is also located on the side wall of the tank, above and connected to the slurry drain pipe.

2. The method for controlling the desulfurization and pulping of coke oven flue gas according to claim 1, characterized in that: An overflow valve is provided on the overflow pipe, and a slurry discharge valve is provided at the end of the slurry discharge pipe near the pulping and digestion tank.

3. The method for controlling the desulfurization and pulping of coke oven flue gas according to claim 1, characterized in that: The slurry pipe is also connected to a cleaning pipe, and the cleaning pipe is equipped with a cleaning valve.

4. The method for controlling the desulfurization and pulping of coke oven flue gas according to claim 1, characterized in that: A manual butterfly valve is installed at one end of the slurry pipe near the slurry inlet to control the slurry flow rate.

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