Polymeric ferric aluminum sulfate oxidation system and use method

Abstract

The invention discloses a polymeric ferric sulfate aluminum oxidation system which comprises a reaction tank, an oxygen tank, a stock solution pulp pool and a qualified pulp pool, the oxygen tank is connected with the reaction tank through an oxygen adding pipe, and an oxygen inlet valve is further installed on the oxygen adding pipe; the device further comprises a buffer metering tank, the buffer metering tank is provided with a second pipeline, a feeding pipe and a charging pipe, and the two ends of the second pipeline are connected with the upper portion of the reaction tank and the upper portion of the buffer metering tank respectively. The two ends of the feeding pipe are respectively connected with the buffer metering tank and the stock solution pulp pool, and a feeding pump and a feeding valve are further arranged on a pipe body of the feeding pipe; two ends of the feeding pipe are respectively connected with the bottom of the buffer metering tank and the upper part of the reaction tank; a circulating centrifugal pump and a feeding valve are arranged on the feeding pipe; a discharge pipe is arranged at the bottom of the reaction tank, two ends of the discharge pipe are respectively connected with the bottom of the reaction tank and a qualified slurry pool, and a slurry discharge valve is further arranged on the discharge pipe. The device has the advantages of novel structure, high oxidation efficiency and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of equipment for preparing polyferric aluminum sulfate, and particularly to a gas-liquid transformation position buffer device for a polyferric aluminum sulfate oxidation system. Background Art

[0002] Polyferric aluminum sulfate (PFAS) is developed on the basis of polyferric sulfate (PFS) and is a new type of highly efficient water treatment agent that combines the advantages of PFS. It can be widely used for coagulation and precipitation treatment of various wastewaters, industrial waters, and drinking waters. As a new type of water treatment agent, polyferric aluminum sulfate must have good flocculation effects to have a development prospect. Through a series of coagulation experiments, comparing PFS and PFAS with the same molar concentration, observing the flocculation effect of PFAS, visually observing the turbidity change, it is found that compared with the sample adding PFS with the same molar concentration, the precipitate flocs generated by adding PFAS are larger, settle faster, and the turbidity of the water sample is lower, and the effect is significantly better.

[0003] The existing patent document CN103991912B discloses a synthesis process of polyferric aluminum sulfate, which uses by-product ferrous sulfate heptahydrate and titanium white waste acid produced by the sulfuric acid method as raw materials and liquid oxygen as an oxidant, and synthesizes polyferric aluminum sulfate by changing the reaction temperature and reaction time. It adopts a traditional oxidation system.

[0004] The disclosure of the above background art content is only used to assist in understanding the concept and technical solution of the present invention, and it does not necessarily belong to the prior art of this patent application. Without clear evidence indicating that the above content was publicly available on the filing date of this patent application, the above background art should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0005] The main object of the present invention is to propose a polyferric aluminum sulfate oxidation system with good oxidation continuity and high efficiency, and at the same time propose a usage method of this oxidation system.

[0006] To this end, the present invention proposes a polyferric aluminum sulfate oxidation system and a usage method.

[0007] Preferably, the present invention can also have the following technical features:

[0008] The polyferric aluminum sulfate oxidation system includes a reaction tank, an oxygen tank, a raw liquid slurry tank, and a qualified slurry tank. The oxygen tank is connected to the reaction tank through an oxygen addition pipe, and an oxygen inlet valve is also installed on the oxygen addition pipe. It further includes a buffer metering tank, and the buffer metering tank is provided with a second pipeline, a feeding pipe, and a dosing pipe. Among them,

[0009] Both ends of the second pipeline are respectively connected to the upper part of the reaction tank and the upper part of the buffer metering tank;

[0010] Both ends of the feeding pipe are respectively connected to the buffer metering tank and the raw liquid pulp pool, and a feeding pump and a feeding valve are further arranged on the pipe body;

[0011] Both ends of the feeding pipe are respectively connected to the bottom of the buffer metering tank and the upper part of the reaction tank; a circulating centrifugal pump and a feeding valve are arranged on the feeding pipe;

[0012] A discharge pipe is arranged at the bottom of the reaction tank. Both ends of the discharge pipe are respectively connected to the bottom of the reaction tank and the qualified pulp pool, and a pulp discharge valve is further arranged on the discharge pipe.

[0013] Further, the volume of the buffer metering tank is smaller than that of the reaction tank.

[0014] Further, a low-pressure liquid seal connecting pipe is further included. Both ends of the low-pressure liquid seal connecting pipe are respectively connected to the top of the reaction tank and the raw liquid pulp pool, and a safety valve is further arranged in the middle of the pipe body.

[0015] Further, one end of the low-pressure liquid seal connecting pipe extends below the slurry liquid level of the raw liquid pulp pool.

[0016] Further, one end of the oxygen adding pipe extends into the middle of the reaction tank.

[0017] Further, one end of the feeding pipe extends to the middle of the buffer metering tank.

[0018] Further, a branch is arranged at one end of the feeding pipe connected to the reaction tank.

[0019] Further, a first valve is further included. The first valve is installed on the pipeline of the feeding pipe between the feeding valve and the circulating centrifugal pump.

[0020] Further, a connecting pipe is further included. One end of the connecting pipe is connected to the pipeline of the discharge pipe between the pulp discharge valve and the reaction tank, and the other end is connected to the pipeline of the feeding pipe between the feeding valve and the first valve.

[0021] A using method of a polyferric aluminum sulfate oxidation system including the above-mentioned one comprises the following steps:

[0022] In the starting stage, raw liquid slurry and oxygen are introduced into the reaction tank, the buffer metering tank is filled with oxygen, the volume of oxygen in the buffer metering tank is the same as the volume of the raw liquid slurry in the reaction tank, and all pipeline valves are closed to make the air pressure in the reaction tank reach the preset air pressure;

[0023] In the reaction stage, the oxygen inlet valve is opened to continuously input oxygen into the reaction tank for oxidation reaction. After the oxidation reaction ends, the oxygen inlet valve is closed, and the pulp discharge valve is opened to discharge pulp; when discharging pulp, the feeding pump and the feeding valve are opened to input raw liquid slurry into the buffer metering tank, and the feeding pump is stopped and the feeding valve is closed after the buffer metering tank is filled with raw liquid slurry;

[0024] In the circulation stage, turn on the circulating centrifugal pump and the feed valve, and pump the stock solution slurry in the buffer metering tank into the reaction tank, so that the oxygen in the reaction tank is exchanged back to the buffer metering tank through the second pipeline; after all the stock solution slurry is input into the reaction tank, turn off the circulating centrifugal pump and the feed valve, and open the oxygen inlet valve to continuously input oxygen into the reaction tank for oxidation reaction, and enter the reaction stage of repeating the above steps.

[0025] The beneficial effects of the present invention compared with the prior art include: in this embodiment, 26 cubic meters of stock solution slurry is oxidized in each cycle. By setting up the buffer metering tank, it plays the role of quantitative, transitional and material exchange. It operates in multiple cycles during the working hours, with strong work continuity and high work efficiency. When discharging the slurry, turn on the feed pump and the feeding valve to input 26 cubic meters of stock solution slurry into the buffer metering tank, and press the 26 cubic meters of oxygen in the buffer metering tank back to the reaction tank through the second pipeline, preventing the reaction tank from being overly flattened due to negative pressure and accelerating the slurry discharge. The circulating centrifugal pump can not only transport the stock solution slurry, but also circulate the stock solution slurry in the reaction tank, which can improve the oxidation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic structural diagram of the present invention, showing the operation of oxygen and slurry during the oxidation reaction.

[0027] Figure 2 Showing the operation of oxygen and slurry during slurry discharge.

[0028] Figure 3 Showing the operation of oxygen and slurry when the buffer metering tank feeds the reaction tank. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The present invention will be further described in detail below in conjunction with the specific embodiments and with reference to the accompanying drawings. It should be emphasized that the following description is merely exemplary and not intended to limit the scope of the present invention and its applications.

[0030] Referring to the following drawings, non-limiting and non-exclusive embodiments will be described, where like reference numerals represent like components, unless otherwise specifically stated.

[0031] As Figures 1 to 3The shown polyaluminum ferric sulfate oxidation system includes a reaction tank 2, an oxygen tank 1, a buffer metering tank 3, a stock solution pulp tank 4 and a qualified pulp tank 5. The oxygen tank 1 is connected to the reaction tank 2 through an oxygen addition pipe 12, and an oxygen inlet valve 11 is also installed on the oxygen addition pipe 12. The buffer metering tank 3 is provided with a second pipeline 8, a feeding pipe 9 and a feeding pipe 31. Among them, both ends of the second pipeline 8 are respectively connected to the upper part of the reaction tank 2 and the upper part of the buffer metering tank 3. The second pipeline 8 serves as a channel for oxygen to move between the buffer metering tank 3 and the reaction tank 2. Both ends of the feeding pipe 9 are respectively connected to the buffer metering tank 3 and the stock solution pulp tank 4. Preferably, a feeding pump 91 and a feeding valve 92 are also provided on the feeding pipe 9. Both ends of the feeding pipe 31 are respectively connected to the bottom of the buffer metering tank 3 and the upper part of the reaction tank 2, and are used to transport the slurry in the buffer metering tank 3 to the reaction tank 2. Preferably, a circulating centrifugal pump 32 and a feeding valve 34 are provided on the feeding pipe 31, and the feeding valve 34 is installed between the circulating centrifugal pump 32 and the buffer metering tank 3. A discharge pipe 51 is also provided at the bottom of the reaction tank 2, and both ends of the discharge pipe 51 are respectively connected to the bottom of the reaction tank 2 and the top of the qualified pulp tank 5. Preferably, a slurry discharge valve 52 is also provided on the discharge pipe 51. In this embodiment, the buffer metering tank 3 is a 26-cubic-meter tank. Optionally, the buffer metering tank 3 includes a middle cylindrical section, and an upper cone and a lower cone connected to both ends of the cylindrical section. The reaction tank 2 is a 28-cubic-meter tank, and the reaction tank 2 is a round tank or a square tank. A pressure gauge is provided to measure the pressure of the reaction tank 2.

[0032] It further includes a low-pressure liquid seal connecting pipe 7. Both ends of the low-pressure liquid seal connecting pipe 7 are respectively connected to the top of the reaction tank 2 and the stock solution pulp tank 4, and a safety valve 71 is provided in the middle. When the pressure in the reaction tank 2 exceeds a preset value, the safety valve 71 opens, and discharges the oxygen in the reaction tank 2 into the stock solution pulp tank 4, effectively preventing the pressure in the reaction tank 2 from being too high. Preferably, one end of the low-pressure liquid seal connecting pipe 7 extends into the slurry in the stock solution pulp tank 4, and this port is kept below the slurry liquid level. In this way, during operation, it can exhaust and reduce pressure through the low-pressure liquid seal connecting pipe 7, and can also prevent air from entering the reaction tank 2 through the low-pressure liquid seal connecting pipe 7.

[0033] Preferably, one end of the oxygen addition pipe 12 extends into the interior of the reaction tank 2 and extends downward to the middle of the reaction tank 2, which can improve the contact between oxygen and the slurry in the reaction tank 2.

[0034] Preferably, one end of the feeding pipe 9 extends to the middle of the buffer metering tank 3.

[0035] More preferably, the end of the feeding pipe 31 connected to the reaction tank 2 is provided with branches, preferably 2 branches, and the slurry is injected into the reaction tank 2 through 2 branches, increasing the contact between the slurry and oxygen.

[0036] It also includes a connecting pipe 35 and a first valve 33. The front end of the connecting pipe 35 is connected to the discharge pipe 51, and the rear end is connected to the feeding pipe 31. Specifically, the front end of the connecting pipe 35 is connected to the pipeline of the discharge pipe 51 between the discharge valve 52 and the reaction tank 2, the first valve 33 is installed on the pipeline of the feeding pipe 31 between the feeding valve 34 and the circulating centrifugal pump 32, and the rear end of the connecting pipe 35 is connected to the pipeline of the feeding pipe 31 between the feeding valve 34 and the first valve 33.

[0037] The using method of the polyaluminum ferric sulfate oxidation system includes:

[0038] In the initial stage, 26 cubic meters of original liquid slurry and 2 cubic meters of oxygen are input into the reaction tank 2, 26 cubic meters of oxygen are input into the buffer metering tank 3, and all pipeline valves are closed, including the discharge valve 52, the oxygen inlet valve 11, the feeding valve 92, the first valve 33 and the feeding valve 34; preferably, the air pressure in the reaction tank 2 reaches 0.02 MPa.

[0039] In the reaction stage, combined with Figure 1 、 2 , the oxygen inlet valve 11 is opened to continuously input oxygen into the reaction tank 2 for oxidation reaction. After the oxidation reaction is completed, the oxygen inlet valve 11 is closed, the discharge valve 52 is opened, and 26 cubic meters of qualified slurry are discharged into the qualified slurry tank 5, and then the discharge valve 52 is closed; during discharging, the feeding pump 91 and the feeding valve 92 are opened to input 26 cubic meters of original liquid slurry into the buffer metering tank 3, and 26 cubic meters of oxygen in the buffer metering tank 3 are pressed back into the reaction tank 2 through the second pipeline 8 to prevent the reaction tank 2 from being overly flattened due to negative pressure and to accelerate discharging until the slurry in the buffer metering tank 3 reaches 26 cubic meters, then the feeding pump 91 is stopped and the feeding valve 92 is closed. That is to say, at the beginning of the reaction stage, there are 26 cubic meters of oxygen in the buffer metering tank 3, 26 cubic meters of original liquid slurry and 2 cubic meters of oxygen in the reaction tank 2; when the discharging is completed, there are 26 cubic meters of original liquid slurry in the buffer metering tank 3 and 28 cubic meters of oxygen in the reaction tank 2. Preferably, the circulating centrifugal pump 32 is opened to circulate the slurry in the reaction tank 2 during the oxidation reaction process, at this time the feeding valve 34 is in the closed state, and the circulating centrifugal pump 32 is closed after the oxidation reaction is completed to improve the oxidation efficiency.

[0040] In the circulation stage, combined with Figure 2 、 3, turn on the circulating centrifugal pump 32, the first valve 33 and the feed valve 34, and pump the stock solution slurry in the buffer metering tank 3 into the reaction tank 2, so that the oxygen in the reaction tank 2 is exchanged back to the buffer metering tank 3 through the second pipeline 8; after all 26 cubic meters of the stock solution slurry are input into the reaction tank 2, turn off the circulating centrifugal pump 32, the first valve 33 and the feed valve 34, and open the oxygen inlet valve 11 to continuously input oxygen into the reaction tank 2 for the oxidation reaction, and enter and repeat the above reaction stage. In this way, in this embodiment, the oxidation reaction of 26 cubic meters of the stock solution slurry is carried out in each cycle. By setting the buffer metering tank 3, the functions of quantitative measurement, transition and material exchange are achieved. The operation is cycled multiple times during the working hours, with strong work continuity and high work efficiency. During the oxidation reaction, the circulating centrifugal pump 32 and the first valve 33 can also be opened, and the feed valve 34 can be closed to improve the oxidation efficiency by circulating the stock solution slurry in the reaction tank 2.

[0041] In the above, during the reaction stage or the circulation stage, the air pressure in the reaction tank 2 is maintained at 0.01 - 0.02 MPa. If the air pressure is lower than 0.01 MPa, the oxygen flow rate is appropriately increased. If the air pressure is higher than 0.02 MPa, the safety valve 71 is opened, and the oxygen enters the stock solution slurry pool 4 through the low-pressure liquid seal connecting pipe 7 and is discharged into the environment.

[0042] Those skilled in the art will recognize that numerous variations to the above description are possible, so the embodiments and the drawings are only used to describe one or more specific embodiments.

[0043] Although the exemplary embodiments that are regarded as the present invention have been described and recited, those skilled in the art will understand that various changes and substitutions can be made thereto without departing from the spirit of the present invention. Additionally, many modifications can be made to adapt a particular situation to the teachings of the present invention without departing from the central concept described herein. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but the present invention may also include all embodiments and their equivalents that fall within the scope of the present invention.

Claims

1. Polyferric aluminum sulfate oxidation system, comprising a reaction tank, an oxygen tank, a stock solution pulp tank and a qualified pulp tank, wherein the oxygen tank is connected to the reaction tank through an oxygen addition pipe, and an oxygen inlet valve is further installed on the oxygen addition pipe; characterized in that: It further includes a buffer metering tank, which is provided with a second pipeline, a feeding pipe and a charging pipe. Among them, Both ends of the second pipeline are respectively connected to the upper part of the reaction tank and the upper part of the buffer metering tank; Both ends of the feeding pipe are respectively connected to the buffer metering tank and the raw slurry tank, and a feeding pump and a feeding valve are also provided on its pipe body; Both ends of the charging pipe are respectively connected to the bottom of the buffer metering tank and the upper part of the reaction tank; a circulating centrifugal pump and a feeding valve are provided on the charging pipe; A discharging pipe is provided at the bottom of the reaction tank, and both ends of the discharging pipe are respectively connected to the bottom of the reaction tank and the qualified slurry tank, and a slurry discharging valve is also provided on the discharging pipe.

2. The polyaluminum ferric sulfate oxidation system according to claim 1, characterized in that: The volume of the buffer metering tank is smaller than that of the reaction tank.

3. The polyferric aluminum sulfate oxidation system according to claim 1, wherein: It further includes a low-pressure liquid seal connecting pipe, and both ends of the low-pressure liquid seal connecting pipe are respectively connected to the top of the reaction tank and the raw slurry tank, and a safety valve is also provided in the middle of the pipe body.

4. The polyferric aluminum sulfate oxidation system according to claim 3, wherein: One end of the low-pressure liquid seal connecting pipe extends below the slurry liquid level of the raw slurry tank.

5. The polyferric aluminum sulfate oxidation system according to claim 1, wherein: One end of the oxygen adding pipe extends into the middle of the reaction tank.

6. The polyferric aluminum sulfate oxidation system according to claim 1, wherein: One end of the feeding pipe extends to the middle of the buffer metering tank.

7. The polyferric aluminum sulfate oxidation system according to claim 1, characterized in that: A branch is provided at one end of the charging pipe connected to the reaction tank.

8. The polyferric aluminum sulfate oxidation system according to claim 1, wherein: It further includes a first valve, and the first valve is installed on the pipeline of the charging pipe between the feeding valve and the circulating centrifugal pump.

9. The polyferric aluminum sulfate oxidation system according to claim 8, wherein: It further includes a connecting pipe, one end of the connecting pipe is connected to the pipeline of the discharging pipe between the slurry discharging valve and the reaction tank, and the other end is connected to the pipeline of the charging pipe between the feeding valve and the first valve.

10. A method for using the polyaluminum ferric sulfate oxidation system according to claim 1, characterized in that, It includes the following steps: In the initial stage, raw slurry and oxygen are introduced into the reaction tank, the buffer metering tank is filled with oxygen, the volume of oxygen in the buffer metering tank is the same as the volume of the raw slurry in the reaction tank, and all pipeline valves are closed to make the air pressure in the reaction tank reach the preset air pressure; In the reaction stage, the oxygen inlet valve is opened to continuously input oxygen into the reaction tank for oxidation reaction. After the oxidation reaction is completed, the oxygen inlet valve is closed, and the slurry discharging valve is opened to discharge slurry; when discharging slurry, the feeding pump and the feeding valve are opened to input raw slurry into the buffer metering tank, and the feeding pump is stopped and the feeding valve is closed after the buffer metering tank is filled with raw slurry; In the circulation stage, the circulating centrifugal pump and the feeding valve are opened to pump the raw slurry in the buffer metering tank into the reaction tank, so that the oxygen in the reaction tank is exchanged back to the buffer metering tank through the second pipeline; after all the raw slurry is input into the reaction tank, the circulating centrifugal pump and the feeding valve are closed, and the oxygen inlet valve is opened to continuously input oxygen into the reaction tank for oxidation reaction, and then enter the above-mentioned reaction stage again.

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