Graded pressure reduction and negative pressure stripping ozone reaction system

Abstract

The utility model discloses a graded depressurization and negative pressure stripping ozone reaction system, and belongs to the technical field of sewage treatment systems. The device comprises a first-stage catalytic oxidation tank, a second-stage ozone release tank and a third-stage negative pressure release and air stripping tank which are sequentially connected through pipelines, catalysts are arranged in the first-stage catalytic oxidation tank and the second-stage ozone release tank, and an aeration disc is arranged at the bottom of the third-stage negative pressure release and air stripping tank; and tail gas of the first-stage catalytic oxidation tank and the second-stage ozone release tank is controlled to be discharged by an electromagnetic valve, and enters an aeration disc in the third-stage negative pressure release and air stripping tank through a one-way valve. The tank body pressures of the first-stage catalytic oxidation tank, the second-stage ozone release tank and the third-stage negative pressure release and stripping tank are sequentially reduced. According to the utility model, ozone dissolved gas water releases ozone in batches in a graded pressure reduction manner, so that the ozone is efficiently utilized; air stripping is carried out under the negative pressure condition of the three-stage reaction tank, the denitrification effect is enhanced, front-end ozone tail gas is secondarily utilized, the ozone utilization rate is increased, and the COD removal effect is enhanced.

Description

Technical Field

[0001] The utility model belongs to the technical field of sewage treatment systems, and particularly relates to a step-down and negative-pressure stripping ozone reaction system with grading. Background Art

[0002] Sewage treatment is a process of purifying sewage to meet the water quality requirements for drainage or reuse. With the increasing attention to environmental protection and the full utilization of water resources, sewage treatment is widely applied in various fields such as construction, agriculture, transportation, energy, petrochemical industry, and environmental protection. Generally, according to the source of sewage, sewage treatment is generally divided into production sewage treatment and domestic sewage treatment. Among them, production sewage includes industrial sewage, agricultural sewage, etc. Taking industrial production sewage as an example, in industries such as oil fields, refineries, petrochemical industries, metallurgy, steel, and paper making, a large amount of sewage containing various pollutants such as oil and organic substances will be produced every day.

[0003] At present, the main treatment methods for sewage are ozone oxidation technology, air flotation separation technology, or a combination of the two. Ozone catalytic oxidation technology can effectively remove organic substances after secondary treatment of sewage. However, in the existing pressurized ozone catalytic oxidation reaction device, due to the increase in the solubility of ammonia nitrogen under high pressure, its denitrification effect is poor. At the same time, the conventional ammonia nitrogen stripping tower has a high energy consumption for atmospheric pressure stripping, the nitrogen removal effect is average, the ozone utilization rate is low, and the catalytic oxidation efficiency is low. Further optimization is required to improve its reaction efficiency and reduce the operating cost. For this reason, a step-down and negative-pressure stripping ozone reaction system with grading is proposed to solve the above problems. Content of the Utility Model

[0004] The purpose of the utility model is to provide a step-down and negative-pressure stripping ozone reaction system with grading, aiming to solve the problems in the existing sewage treatment technology such as low ozone utilization rate, low catalytic oxidation efficiency, low reaction efficiency, and high operating cost in the background art. To achieve the above purpose, the technical solution adopted by the utility model is: a step-down and negative-pressure stripping ozone reaction system with grading, which includes a first-stage catalytic oxidation tank, a second-stage ozone release tank, and a third-stage negative-pressure release and stripping tank connected in sequence through pipelines. A mixing device for mixing sewage and ozone is arranged at the front end of the first-stage catalytic oxidation tank. Catalysts are arranged in both the first-stage catalytic oxidation tank and the second-stage ozone release tank. The water inlet of the third-stage negative-pressure release and stripping tank is connected to a spray head at the top inside the tank body, and an aeration disc is arranged at the bottom of the third-stage negative-pressure release and stripping tank. The tank body pressures of the first-stage catalytic oxidation tank, the second-stage ozone release tank, and the third-stage negative-pressure release and stripping tank decrease in sequence. This technical solution enables the ozone-dissolved water to release ozone in batches by means of step-down and grading, achieving more efficient utilization of ozone; at the same time, stripping is carried out under the negative-pressure condition of the third-stage negative-pressure release and stripping tank to enhance the denitrification effect.

[0005] For further description of the foregoing solution, a part of the sewage after reaction in the secondary ozone release tank is refluxed to the front end of the mixing device through a secondary reflux pump. The mixing device uses a jet ejector. A part of the sewage is pumped into the tertiary negative pressure release and stripping tank by a lift pump. The sewage is evenly sprayed from the nozzles at the top of the tank body, and the remaining ozone is released under negative pressure to react with the sewage. A part of the sewage after being treated in the tertiary negative pressure release and stripping tank enters the jet ejector through a tertiary reflux pump, and the remaining sewage is discharged to the water outlet end.

[0006] More preferably, the catalysts in the primary catalytic oxidation tank and the secondary ozone release tank adopt composite ozone catalysts, and a sieve plate is also provided in the tank body to promote the ozone oxidation reaction.

[0007] Furthermore, a central draft tube is provided inside the primary catalytic oxidation tank and the secondary ozone release tank. The top of the central draft tube is higher than the catalyst to maintain the liquid level, ensure that the water flow passes through the catalyst area, and then divert the treated sewage out.

[0008] Furthermore, the pressures of the three tank bodies of the primary catalytic oxidation tank, the secondary ozone release tank, and the tertiary negative pressure release and stripping tank decrease in sequence, and the tank body pressures are positive pressure, slightly positive pressure, and negative pressure respectively. The sequentially decreasing pressures can enable the ozone in the dissolved air water to be released in batches, and efficiently utilize ozone for reaction. The aeration disk is arranged in the tertiary negative pressure release and stripping tank with negative pressure, which can reduce the partial pressure of ammonia nitrogen in the gas phase and improve the stripping efficiency of ammonia nitrogen in the sewage.

[0009] More preferably, a packing layer and a sieve plate are provided inside the tertiary negative pressure release and stripping tank to increase the gas-liquid contact area, increase the contact time, and improve the ozone reaction and air stripping efficiency. The packing mainly consists of alumina, which can play a catalytic role in the reaction between ozone and sewage.

[0010] For further description of the foregoing solution, the tail gases of the primary catalytic oxidation tank and the secondary ozone release tank are discharged under the control of electromagnetic valves, and are mixed with air in the aeration pipeline of the tertiary negative pressure release and stripping tank through one-way valves, and the tail gases are reused in the tertiary tank to improve the ozone utilization rate.

[0011] A water separation tank is provided in front of the negative pressure pump of the tertiary negative pressure release and stripping tank to prevent sewage from accidentally entering the exhaust system. The water in the water separation tank can be automatically discharged into the tertiary tank after shutdown. The tail gas at the top of the tertiary negative pressure release and stripping tank is connected to the water separation tank through a pipeline. A certain height of liquid level is left at the bottom of the tertiary negative pressure release and stripping tank, which can maintain the stability of reflux and increase the contact time between the aeration disk and the sewage.

[0012] More preferably, the sensors, water pumps, electromagnetic valves, and vacuum pumps in the system are fully automatically controlled by a PLC programmable logic controller or DCS.

[0013] Compared with the prior art, the utility model makes the ozone dissolved gas water release ozone in batches by means of hierarchical pressure reduction, achieving more efficient utilization of ozone; stripping is carried out under the negative pressure condition of the three-stage reaction tank to strengthen the denitrification effect, and the ozone tail gas at the front end is reused to improve the ozone utilization rate and enhance the COD removal effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a principle block diagram provided by an embodiment of the utility model.

[0015] Among them, the reference numerals in the figure are as follows:

[0016] 1. Air intake end; 2. Ozone intake end; 3. Sewage intake end; 4. Exhaust end; 5. Water outlet end;

[0017] 101. Feed water pump; 102. Ejector; 103. First-stage catalytic oxidation tank; 104. Central diversion pipe; 105. Ozone catalyst;

[0018] 201. Second-stage ozone release tank; 202. Check valve; 203. Second-stage reflux pump; 204. Lift pump;

[0019] 301. Third-stage negative pressure release and stripping tank; 302. Sprinkler head; 303. Packing layer; 304. Aeration disc; 305. Third-stage reflux pump; 306. Water isolation tank; 307. Vacuum pump. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] In order to facilitate the understanding of the utility model, the utility model will be described more comprehensively below with reference to the relevant drawings. The preferred embodiments of the utility model are shown in the drawings. However, the utility model can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided so that the disclosure of the utility model can be understood more thoroughly and comprehensively.

[0021] The technical solution of this patent will be further described in detail below in combination with the specific embodiments.

[0022] Please refer to Figure 1, the present utility model provides a step-down and negative pressure stripping ozone reaction system, which includes a first-stage catalytic oxidation tank 103, a second-stage ozone release tank 201, and a third-stage negative pressure release and stripping tank 301 connected in sequence through pipelines. A mixing device for mixing sewage and ozone is provided at the front end of the first-stage catalytic oxidation tank 103. Catalysts are provided in both the first-stage catalytic oxidation tank 103 and the second-stage ozone release tank 201. The water inlet of the third-stage negative pressure release and stripping tank 301 is connected to a spray head 302 at the top inside the tank body, and an aeration disc 304 is provided at the bottom of the third-stage negative pressure release and stripping tank 301. The tank pressures of the first-stage catalytic oxidation tank 103, the second-stage ozone release tank 201, and the third-stage negative pressure release and stripping tank 301 decrease in sequence. The catalysts in the first-stage catalytic oxidation tank 103 and the second-stage ozone release tank 201 adopt a composite ozone catalyst 105, and a sieve plate is also provided inside the tank body to promote the ozone oxidation reaction. A central draft tube 104 is provided inside the first-stage catalytic oxidation tank 103 and the second-stage ozone release tank 201. The top of the central draft tube 104 is higher than the catalyst to maintain the liquid level, ensure that the water flows through the catalyst area, and then divert the treated sewage out. The sensors, water pumps, solenoid valves, and vacuum pump 307 in the system are fully automatically controlled by a PLC programmable logic controller or a DCS.

[0023] Part of the sewage after the reaction in the second-stage ozone release tank 201 is refluxed to the front end of the mixing device through a second-stage reflux pump 203. The mixing device adopts a jet pump 102. Part of the sewage is pumped into the third-stage negative pressure release and stripping tank 301 by a lift pump 204. The sewage is evenly sprayed from the spray head 302 at the top of the tank body, and the remaining ozone is released under negative pressure to react with the sewage. The tail gases of the first-stage catalytic oxidation tank 103 and the second-stage ozone release tank 201 are discharged under the control of a solenoid valve, and pass through a check valve 202 to be mixed with air in the aeration pipeline of the third-stage negative pressure release and stripping tank 301, so as to reuse the tail gases in the third-stage tank and improve the ozone utilization rate.

[0024] Part of the sewage treated by the three - stage negative - pressure release and stripping tank 301 enters the ejector 102 through the three - stage reflux pump 305, and the remaining sewage is discharged to the water outlet end 5. The pressures of the three tanks, namely the primary catalytic oxidation tank 103, the secondary ozone release tank 201, and the three - stage negative - pressure release and stripping tank 301, decrease in sequence. The tank pressures are positive pressure, slightly positive pressure, and negative pressure respectively. The decreasing pressures in sequence can cause the ozone in the dissolved - air water to be released in batches, making efficient use of ozone for the reaction. The aeration disk 304 is installed in the three - stage negative - pressure release and stripping tank 301 with negative pressure, which can reduce the partial pressure of ammonia nitrogen in the gas phase and improve the stripping efficiency of ammonia nitrogen in the sewage. A packing layer 303 and a sieve plate are arranged inside the three - stage negative - pressure release and stripping tank 301 to increase the gas - liquid contact area, increase the contact time, and improve the ozone reaction and air stripping efficiency. The packing is mainly composed of alumina, which can play a catalytic role in the reaction between ozone and sewage. A water - separating tank 306 is installed in front of the negative - pressure pump of the three - stage negative - pressure release and stripping tank 301 to prevent sewage from accidentally entering the exhaust system. The water in the water - separating tank 306 can be automatically discharged into the three - stage tank after shutdown. The tail gas at the top of the three - stage negative - pressure release and stripping tank 301 is connected to the water - separating tank 306 through a pipeline. A certain liquid level height is reserved at the bottom of the three - stage negative - pressure release and stripping tank 301, which can maintain the stability of the reflux and increase the contact time between the aeration disk 304 and the sewage.

[0025] To understand the disclosed content of the present utility model more thoroughly and comprehensively, the following further explains its principle in combination with the usage method.

[0026] During actual operation, please refer to Figure 1As shown, sewage is pumped from the sewage inlet end 3 by the feed pump 101 into the ejector 102, and ozone enters the ejector 102 from the ozone inlet end 2. The sewage and ozone are mixed in the ejector 102 to form dissolved air water, and then enter the lower end of the first-stage catalytic oxidation tank 103. The pressure inside this tank is normal pressure. The dissolved air water rises to the ozone catalyst 105 and flows out from the top of the central draft tube 104. Part of the ozone in the dissolved air water is released to form a large number of microbubbles, which react with pollutants under the action of the catalyst. The bottom of the central draft tube 104 is connected to the bottom of the second-stage ozone release tank 201 through a valve, and the sewage that has been treated once is discharged into the second-stage ozone release tank 201. After the sewage enters the second-stage ozone release tank 201, it rises through the ozone catalyst 105 and flows out from the top of the central draft tube 104. The pressure inside this tank is lower than the pressure inside the first-stage catalytic oxidation tank 103. The remaining ozone in the sewage is released again to form microbubbles for a secondary reaction. The bottom of the central draft tube 104 is connected to the nozzle 302 at the top of the third-stage negative pressure release and stripping tank 301 through the lift pump 204. The sewage that has been treated twice is evenly sprayed at the nozzle 302 at the top, and the remaining ozone is released under negative pressure for reaction. Compressed air enters the aeration disc 304 at the bottom of the third-stage negative pressure release and stripping tank 301 from the air inlet end 1. At the same time, the tail gases of the first-stage catalytic oxidation tank 103 and the second-stage ozone release tank 201 enter the aeration disc 304 together with the air through the solenoid valve and the one-way valve 202. Ozone and air are used to strip nitrogen from the sewage, and the tail gas is reused in the third-stage tank to improve the ozone utilization rate. The third-stage negative pressure release and stripping tank 301 is under negative pressure, and this tank is connected to the water isolation tank 306 and the vacuum pump 307 to extract the air at the top of the tank to the exhaust end 4. The third-stage negative pressure release and stripping tank 301 is provided with packing and sieve plates, which can increase the gas-liquid contact area, increase the contact time, and improve the ozone reaction and air stripping efficiency. The packing in the third-stage tank is mainly composed of alumina, which can play a catalytic role in the reaction between ozone and sewage. It should be noted that part of the sewage treated by the second-stage ozone release tank 201 is pumped to the front end of the ejector 102 by the second-stage reflux pump 203, and part of the sewage treated by the third-stage negative pressure release and stripping tank 301 is pumped to the front end of the ejector 102 by the third-stage reflux pump 305, and the rest is discharged to the water outlet end 5.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this utility model belongs. The terms used in the description of this utility model herein are only for the purpose of describing specific embodiments, and are not intended to limit this utility model. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0028] The above embodiments are only used to illustrate the present utility model and are not intended to limit the present utility model. Those of ordinary skill in the relevant technical field can also make various changes and modifications without departing from the spirit and scope of the present utility model. Therefore, all equivalent technical solutions also fall within the scope of the present utility model. The patent protection scope of the present utility model shall be defined by the claims.

Claims

1. A graded pressure reduction and negative pressure stripping ozone reaction system, comprising a primary catalytic oxidation tank (103), a secondary ozone release tank (201), and a tertiary negative pressure release and stripping tank (301) connected in sequence by pipelines, characterized in that: A mixing device for mixing sewage and ozone is arranged at the front end of the primary catalytic oxidation tank (103); catalysts are arranged in the primary catalytic oxidation tank (103) and the secondary ozone release tank (201); a water inlet of the tertiary negative pressure release and blow-off tank (301) is connected to a nozzle (302) at the top of the tank body, and an aeration plate (304) is arranged at the bottom of the tertiary negative pressure release and blow-off tank (301); and the tank body pressures of the primary catalytic oxidation tank (103), the secondary ozone release tank (201), and the tertiary negative pressure release and blow-off tank (301) are sequentially reduced.

2. The step-by-step decompression and negative pressure stripping ozone reaction system according to claim 1 is characterized in that: Part of the sewage after the reaction in the secondary ozone release tank (201) is refluxed to the front end of the mixing device through the secondary reflux pump (203), and the mixing device is an ejector (102). Part of the sewage is pumped into the tertiary negative pressure release and blow-off tank (301) through the lifting pump (204), and the sewage is evenly sprayed from the nozzle (302) on the top of the tank body, and the remaining ozone is released under negative pressure to react with the sewage; part of the sewage treated in the tertiary negative pressure release and blow-off tank (301) enters the ejector (102) through the tertiary reflux pump (305), and the remaining sewage is discharged to the water outlet (5).

3. The step-by-step decompression and negative pressure stripping ozone reaction system according to claim 1 is characterized in that: The first-stage catalytic oxidation tank (103) and the second-stage ozone release tank (201) are provided with a composite ozone catalyst (105) and a sieve plate to promote the ozone oxidation reaction.

4. The step-by-step decompression and negative pressure stripping ozone reaction system according to claim 1 is characterized in that: The primary catalytic oxidation tank (103) and the secondary ozone release tank (201) are provided with a central flow guide pipe (104), and the top of the central flow guide pipe (104) is higher than the catalyst.

5. The step-by-step decompression and negative pressure stripping ozone reaction system according to claim 1 is characterized in that: The pressures of the three tanks, namely, the primary catalytic oxidation tank (103), the secondary ozone release tank (201), and the tertiary negative pressure release and blow-off tank (301), decrease in sequence, and the tank pressures are respectively positive pressure, slightly positive pressure, and negative pressure.

6. The step-by-step decompression and negative pressure stripping ozone reaction system according to claim 1 is characterized in that: The three-stage negative pressure release and blow-off tank (301) is provided with a packing layer (303) and a sieve plate to increase the gas-liquid contact area.

7. The step-by-step decompression and negative pressure stripping ozone reaction system according to claim 1 is characterized in that: The tail gas from the primary catalytic oxidation tank (103) and the secondary ozone release tank (201) is discharged under the control of a solenoid valve and mixed with air in the aeration pipeline of the tertiary negative pressure release and stripping tank (301) through a one-way valve (202).

8. The step-by-step decompression and negative pressure stripping ozone reaction system according to claim 1 is characterized in that: A water-blocking tank (306) is provided in front of the negative pressure pump of the three-stage negative pressure release and blow-off tank (301), and the tail gas at the top of the three-stage negative pressure release and blow-off tank (301) is connected to the water-blocking tank (306) through a pipeline.

9. A step-by-step decompression and negative pressure stripping ozone reaction system according to any one of claims 1 to 8, characterized in that: The sensors, water pumps, solenoid valves and vacuum pumps (307) in the system are fully automatically controlled by a PLC programmable logic controller or a DCS.

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