A pesticide production wastewater treatment device and method

Abstract

This invention discloses a device and method for treating pesticide production wastewater, belonging to the field of wastewater treatment. The device includes an ozone catalytic oxidation reactor, and further includes a tail gas buffer tank, a tail gas extraction tank, a purification tank, and a transfer tank. The tail gas buffer tank is connected to the ozone catalytic oxidation reactor for collecting tail gas. The tail gas extraction tank is connected to the tail gas buffer tank for extracting ozone and carbon dioxide. The purification tank is connected to the tail gas extraction tank for absorbing carbon dioxide. The transfer tank is connected to the purification tank for transferring ozone to the ozone catalytic oxidation reactor. The method achieves ozone recycling through tail gas treatment, ozone adsorption and desorption, and carbon dioxide absorption. This invention recycles ozone in tail gas, improving the utilization rate of ozone.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a device and method for treating pesticide production wastewater. Background Technology

[0002] A pesticide production wastewater treatment process disclosed in CN108358395B states that "unreacted ozone and gaseous products generated by catalytic oxidation reaction flow from the middle outlet of ozone catalytic oxidation reactor 105 into an integrated tail gas catalytic adsorption reactor 107. The integrated tail gas catalytic adsorption reactor 107 is divided into upper and lower sections. The upper section is filled with particulate adsorbent, which can adsorb unreacted ozone; the lower section is filled with the same catalyst as that in ozone catalytic oxidation reactor 105; ozone and some gaseous products generated in ozone catalytic oxidation reactor 105 undergo catalytic oxidation reaction, and the reaction mixture after reaction is physically adsorbed by particulate adsorbent. The tail gas that meets the emission standards is discharged from tail gas emission port 7." Therefore, it can be seen that in the existing technology, ozone in the tail gas is treated by adsorption, but the ozone in the tail gas is not recycled, which increases the cost of ozone use. Summary of the Invention

[0003] The purpose of this invention is to provide a device and method for treating pesticide production wastewater, which solves the problem of low ozone utilization rate caused by the lack of ozone recycling in existing devices.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a pesticide production wastewater treatment device, comprising an ozone catalytic oxidation reactor, and further comprising a tail gas buffer tank, a tail gas extraction tank, a purification tank, and a transfer tank. The tail gas buffer tank is connected to the ozone catalytic oxidation reactor for collecting tail gas. The tail gas extraction tank is connected to the tail gas buffer tank for extracting ozone and carbon dioxide. The purification tank is connected to the tail gas extraction tank for absorbing carbon dioxide. The transfer tank is connected to the purification tank for transferring ozone to the ozone catalytic oxidation reactor.

[0005] Preferably, the bottom of the exhaust gas buffer cylinder is connected to an exhaust pipe, and a spherical shell is connected to the exhaust pipe. An extraction pipe perpendicular to the exhaust pipe is connected between the spherical shell and the exhaust gas extraction cylinder. An arc-shaped cylinder is rotatably connected inside the spherical shell. A columnar molecular sieve is connected inside the arc-shaped cylinder, and the outer wall of the arc-shaped cylinder is in contact with the inner wall of the spherical shell.

[0006] A first piston plate is slidably connected inside the exhaust gas extraction tube. When the columnar molecular sieve is coaxial with the exhaust pipe, the exhaust gas flows toward the columnar molecular sieve, so that nitrogen in the exhaust gas passes through the columnar molecular sieve and is discharged, and ozone and carbon dioxide are adsorbed on the columnar molecular sieve. When the columnar molecular sieve is coaxial with the extraction tube, the first piston plate moves up, so that ozone and carbon dioxide are desorbed from the columnar molecular sieve.

[0007] Preferably, a transmission pipe connects the exhaust gas extraction cylinder and the purification cylinder, and a first one-way valve is provided on the transmission pipe. The purification cylinder is filled with sodium hydroxide solution. When the first piston plate moves down, ozone and carbon dioxide are transferred to the purification cylinder through the transmission pipe, thereby removing carbon dioxide.

[0008] Preferably, an extraction pipe is connected between the transfer cylinder and the purification cylinder, and a second one-way valve is provided on the extraction pipe. An ozone supply pipe is connected to the ozone catalytic oxidation reactor, and a transfer pipe is connected between the ozone supply pipe and the transfer cylinder. A third one-way valve is provided on the transfer pipe. A second piston plate is slidably connected inside the transfer cylinder. When the second piston plate moves down, it can extract the gas in the purification cylinder. When the second piston plate moves up, it can transfer the gas to the ozone catalytic oxidation reactor.

[0009] Preferably, there are two purification cylinders. Both the extraction tube and the transmission tube are T-shaped. The three ports of the transmission tube are connected to the bottom walls of the two purification cylinders and the bottom wall of the exhaust gas extraction cylinder, respectively. The three ports of the extraction tube are connected to the top walls of the two purification cylinders and the top wall of the transfer cylinder, respectively. A return pipe is connected between the transfer pipe and the section of the transmission tube connected to the exhaust gas extraction cylinder. A first three-way valve is provided at the connection between the transfer pipe and the return pipe. A second three-way valve is provided at the T-shaped intersection of the transmission tube. A third three-way valve is provided at the T-shaped intersection of the extraction tube.

[0010] When the downward movement distance of the second piston plate increases, the first three-way valve, the second three-way valve, and the third three-way valve all operate, so that the transfer cylinder and the exhaust gas extraction cylinder are connected to another purification cylinder, and the transfer cylinder is connected to a section of the transmission pipe connected to the exhaust gas extraction cylinder.

[0011] Preferably, an inner rod is connected to the upper surface of the second piston plate, an outer cylinder is sleeved at the bottom of the inner rod, a spring is connected between the inner rod and the outer cylinder, a rectangular frame is fixedly connected to the bottom of the outer cylinder, a toothed gear is rotatably connected to the inside of the rectangular frame, and teeth that mate with the toothed gear are provided on the two inner walls of the rectangular frame in the vertical direction.

[0012] The bottom of the transfer cylinder is fixedly connected to a bracket, the outer cylinder slides through the bracket, and a displacement sensor for detecting the sliding distance of the outer cylinder is provided on the bracket.

[0013] Preferably, a third piston plate is slidably connected inside the exhaust gas buffer cylinder, a ring is connected to the top of the exhaust gas buffer cylinder, and a pressure spring is connected between the ring and the third piston plate.

[0014] Preferably, a piston cylinder is fixedly connected to the middle of the ring, a piston rod is slidably connected inside the piston cylinder and filled with sodium hydroxide solution, a pressure pipe is fixedly connected to the top of the piston cylinder, and two branch pipes are connected to the pressure pipe. The two branch pipes are respectively connected to the two purification cylinders. When the third piston plate moves up, it can push the piston rod to slide in the piston cylinder, thereby increasing the pressure inside the purification cylinder.

[0015] Preferably, a pressure control tube is connected to the pressurizing tube, and a pressure control cylinder is connected to the end of the pressure control tube. A fourth piston plate is slidably connected inside the pressure control cylinder, and a pressure control spring is connected between the fourth piston plate and the end of the pressure control cylinder.

[0016] A method for treating pesticide production wastewater, using the aforementioned pesticide production wastewater treatment device, includes the following steps:

[0017] Set the rotation time interval of the arc-shaped cylinder so that the arc-shaped cylinder reciprocates within a 90-degree range at set time intervals;

[0018] Ozone is introduced into the ozone catalytic oxidation reactor. The tail gas from the ozone catalytic oxidation reactor enters the tail gas buffer cylinder. Initially, the columnar molecular sieve is in a vertical state. The tail gas gathers in the tail gas buffer cylinder and pushes the third piston plate to move up and compress the pressure spring. After a set time interval is reached, the arc-shaped cylinder rotates 90 degrees, making the columnar molecular sieve horizontal. The pressure spring applies pressure to the third piston plate, so that the tail gas passes through the columnar molecular sieve under pressure. Nitrogen in the tail gas passes through the columnar molecular sieve, and carbon dioxide and ozone are adsorbed on the columnar molecular sieve.

[0019] After the set time interval is reached again, the arc-shaped cylinder rotates 90 degrees, making the columnar molecular sieve vertical. After the control system detects that the columnar molecular sieve is vertical, it controls the first piston plate to move up, providing a negative pressure state inside the spherical shell, so that carbon dioxide and ozone are desorbed from the columnar molecular sieve and enter the tail gas extraction cylinder.

[0020] Set the upward movement distance and time of the first piston plate. When the first piston plate moves up to the set distance and is maintained for the set time, the first piston plate moves down and pushes the ozone and carbon dioxide collected in the exhaust gas extraction tube into the purification tube through the transmission pipe.

[0021] The first piston plate is set to move up and down a predetermined distance and for a predetermined number of cycles over a given time period, thereby removing as much ozone and carbon dioxide as possible from the columnar molecular sieve.

[0022] When ozone and carbon dioxide enter the purification cylinder, carbon dioxide reacts with the sodium hydroxide solution inside the purification cylinder and is largely removed, while ozone passes through the sodium hydroxide solution and accumulates at the top of the purification cylinder.

[0023] When the columnar molecular sieve is in a vertical state, the exhaust pipe is not connected to the spherical shell. At this time, the exhaust gas accumulates in the exhaust gas buffer cylinder, causing the third piston plate to move upward. As a result, the third piston plate pushes the piston rod to slide into the piston cylinder, allowing the sodium hydroxide solution in the piston cylinder to enter the purification cylinder in the working state, increasing the pressure in the purification cylinder in the working state and promoting the absorption of carbon dioxide.

[0024] The timing for the downward movement of the second piston plate is set to be the time after the first piston plate stops operating. After the time after the first piston plate stops operating is reached, the second piston plate moves downward and extracts ozone from the purification cylinder through the extraction pipe. The downward movement of the second piston plate is the height of the transfer cylinder, resulting in a negative pressure state inside the transfer cylinder. After the second piston plate moves downward, the downward pull force applied to the second piston plate is removed, and the negative pressure acts on the second piston plate, causing the second piston plate to move upward. After the second piston plate moves upward and its position stabilizes, an upward thrust is applied to the second piston plate, causing the second piston plate to push the ozone in the transfer cylinder through the transfer pipe into the ozone catalytic oxidation reactor for reuse.

[0025] A reference range for the downward movement distance of the outer cylinder is set. When the second piston plate moves downward, the outer cylinder moves downward synchronously. After the position of the second piston plate stabilizes, the position of the outer cylinder also gradually stabilizes. The displacement sensor detects the downward movement distance of the outer cylinder and compares it with the reference range. If the downward movement distance is greater than the reference range, it indicates that the sodium hydroxide solution in the purification cylinder in the working state is saturated with adsorption. The second piston plate continues to move upward, and at this time, the first three-way valve, the second three-way valve, and the third three-way valve are all in operation, so that the transfer cylinder and the tail gas extraction cylinder are connected to another purification cylinder. The transfer cylinder is connected to the section of the transmission pipe connected to the tail gas extraction cylinder, so that the carbon dioxide that has not been completely adsorbed is passed into another purification cylinder, so that the carbon dioxide is absorbed again.

[0026] After the second piston plate moves to the top of its stroke, the first three-way valve operates, restoring the connection between the transfer cylinder and the ozone catalytic oxidation reactor;

[0027] The control system acquires the operating status of the first three-way valve, the second three-way valve, and the third three-way valve. After the first three-way valve, the second three-way valve, and the third three-way valve operate, and when the outer cylinder moves downward more than the reference range during the subsequent reciprocating motion of the second piston plate, the second three-way valve and the third three-way valve maintain their current state.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] This invention involves discharging the exhaust gas from an ozone catalytic oxidation reactor through an exhaust pipe into an exhaust gas buffer tank. The buffer tank allows the exhaust gas from the ozone catalytic oxidation reactor to be collected and stored when the exhaust pipe is closed. An exhaust gas extraction tank collects carbon dioxide and ozone from the exhaust gas and transports them to a purification tank. The purification tank absorbs carbon dioxide, leaving mostly ozone in the remaining gas. A transfer tank then transports the remaining gas from the purification tank to an ozone supply pipe, where it mixes with the ozone in the supply pipe before entering the ozone catalytic oxidation reactor to participate in the oxidation reaction, thereby improving the utilization rate of ozone. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0031] Figure 2 This is a schematic diagram of the overall structure of the present invention without the support;

[0032] Figure 3 This is a schematic diagram of the structure of the exhaust gas buffer cylinder of the present invention;

[0033] Figure 4 This is a schematic diagram of the structure of the purification cylinder of the present invention;

[0034] Figure 5 This is a schematic diagram of the structure of the transfer cylinder of the present invention;

[0035] Figure 6 This is a schematic diagram of the structure of the reflux pipe of the present invention;

[0036] Figure 7 This is a schematic diagram of the piston cylinder of the present invention.

[0037] In the diagram: 100, support; 110, ozone catalytic oxidation reactor; 120, ozone supply pipe; 130, exhaust pipe; 140, drying cotton; 200, exhaust buffer cylinder; 210, third piston plate; 220, pressure spring; 230, ring; 240, exhaust pipe; 300, exhaust extraction cylinder; 310, rack; 320, full-tooth gear; 330, first piston plate; 340, extraction pipe; 350, spherical shell; 360, arc-shaped cylinder; 370, columnar molecular sieve; 380, electric rotary rod; 390, transmission pipe; 391, first one-way valve; 392, second three-way valve; 400, purification cylinder; 410, extraction pipe; 420, the... 430. Three-way valve; 440. Second check valve; 450. Pressure stabilizing pipe; 460. Filling pipe; 470. Discharge pipe; 471. Piston cylinder; 472. Piston rod; 473. Pressurizing pipe; 480. Pressure control cylinder; 481. Fourth piston plate; 482. Pressure control spring; 483. Pressure control pipe; 500. Transfer cylinder; 510. Transfer pipe; 511. Third check valve; 520. Second piston plate; 530. Inner rod; 531. Outer cylinder; 532. Spring; 540. Rectangular frame; 550. Gear with missing teeth; 560. Return pipe; 561. First three-way valve; 570. Bracket; 571. Displacement sensor. Detailed Implementation

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0039] Reference Figures 1-7 This embodiment provides a technical solution: a pesticide production wastewater treatment device, including an ozone catalytic oxidation reactor 110, and further including a tail gas buffer tank 200, a tail gas extraction tank 300, a purification tank 400, and a transfer tank 500. The tail gas buffer tank 200 is connected to the ozone catalytic oxidation reactor 110 for collecting tail gas, the tail gas extraction tank 300 is connected to the tail gas buffer tank 200 for extracting ozone and carbon dioxide, the purification tank 400 is connected to the tail gas extraction tank 300 for absorbing carbon dioxide, and the transfer tank 500 is connected to the purification tank 400 for transferring ozone to the ozone catalytic oxidation reactor 110.

[0040] The ozone catalytic oxidation reactor 110 is connected to the support 100. Ozone is introduced into the ozone catalytic oxidation reactor 110 through the ozone supply pipe 120 to react, so that the large molecules and difficult-to-biodegrade organic matter in the pesticide wastewater are oxidized into carbon dioxide and water by ozone. The tail gas of the ozone catalytic oxidation reactor 110 is discharged into the tail gas buffer tank 200 through the tail gas pipe 130. The tail gas buffer tank 200 is set so that the tail gas discharged from the ozone catalytic oxidation reactor 110 can be collected and stored when the exhaust pipe 240 is closed. The tail gas extraction tank 300 collects carbon dioxide and ozone in the tail gas and transports carbon dioxide and ozone to the purification tank 400. The purification tank 400 absorbs carbon dioxide, so that most of the remaining gas is ozone. The transfer tank 500 transports the remaining gas in the purification tank 400 to the ozone supply pipe 120, mixes with the ozone in the ozone supply pipe 120 and enters the ozone catalytic oxidation reactor 110 to participate in the oxidation reaction.

[0041] An ozone concentration sensor, such as an ultraviolet absorption detector, is installed at the connection between the ozone supply pipe 120 and the ozone catalytic oxidation reactor 110. A flow regulating valve is installed at the connection between the ozone supply pipe 120 and the ozone supply point. The control system obtains the ozone concentration through the ozone concentration sensor and adjusts the opening of the flow regulating valve in real time to ensure that the ozone concentration entering the ozone catalytic oxidation reactor 110 is within a suitable range.

[0042] The bottom of the exhaust gas buffer cylinder 200 is connected to an exhaust pipe 240, and a spherical shell 350 is connected to the exhaust pipe 240. An extraction pipe 340 perpendicular to the exhaust pipe 240 is connected between the spherical shell 350 and the exhaust gas extraction cylinder 300. An arc-shaped cylinder 360 is rotatably connected inside the spherical shell 350. A columnar molecular sieve 370 is connected inside the arc-shaped cylinder 360, and its outer wall is in contact with the inner wall of the spherical shell 350. A first piston plate 330 is slidably connected inside the exhaust gas extraction cylinder 300. When the columnar molecular sieve 370 is coaxial with the exhaust pipe 240, the exhaust gas flows towards the columnar molecular sieve 370, so that the nitrogen in the exhaust gas passes through the columnar molecular sieve 370 and is emitted, and ozone and carbon dioxide are adsorbed on the columnar molecular sieve 370. When the columnar molecular sieve 370 is coaxial with the extraction pipe 340, the first piston plate 330 moves upward, so that the ozone and carbon dioxide are desorbed from the columnar molecular sieve 370.

[0043] An electric rotating rod 380 is connected to the outer wall of the arc-shaped cylinder 360. The electric rotating rod 380 passes through the spherical shell 350. The control system controls the electric rotating rod 380 to reciprocate at a certain time interval, thereby driving the arc-shaped cylinder 360 to reciprocate, so that the columnar molecular sieve 370 can move to the vertical and horizontal states and stay in the vertical and horizontal states. The columnar molecular sieve 370 can be of type 13X or other types that can absorb carbon dioxide and ozone and allow nitrogen to pass through.

[0044] When the columnar molecular sieve 370 is in a horizontal state, the exhaust gas enters the exhaust gas buffer cylinder 200 through the exhaust pipe 130, and then flows to the columnar molecular sieve 370 through the exhaust pipe 240. This causes carbon dioxide and ozone in the exhaust gas to be adsorbed onto the columnar molecular sieve 370, while nitrogen passes through the columnar molecular sieve 370 and is discharged from the port of the exhaust pipe 240. After a set time interval, the electric rotary rod 380 rotates 90 degrees, making the columnar molecular sieve 370 vertical. At this time, the outer wall of the arc-shaped cylinder 360 blocks the connection between the exhaust pipe 240 and the spherical shell 350, causing the exhaust gas emitted from the ozone catalytic oxidation reactor 110 to accumulate in the exhaust gas buffer cylinder 200. At this point, the control system controls the motor connected to the full-tooth gear 320 to rotate forward, thereby driving the gear 320 to drive the meshing rack 310. The rack 310 moves the first piston plate 330 connected to its bottom upwards to the exhaust gas extraction cylinder 300, creating a negative pressure state inside the exhaust gas extraction cylinder 300. Under this negative pressure, carbon dioxide and ozone are reverse-released from the columnar molecular sieve 370. The reverse-released carbon dioxide and ozone enter the exhaust gas extraction cylinder 300 through the extraction tube 340. The motor starts, causing the full-tooth gear 320 to rotate to a set angle and remain stationary. This allows the first piston plate 330 to maintain its position for a period of time after moving upwards, ensuring sufficient time for the ozone and carbon dioxide on the columnar molecular sieve 370 to reverse. After the full-tooth gear 320 remains stationary for a period, the motor reverses, driving the full-tooth gear 320 to reverse, causing the first piston plate 330 to move downwards, thereby releasing the ozone and carbon dioxide collected in the exhaust gas extraction cylinder 300.

[0045] A transmission pipe 390 connects the exhaust gas extraction cylinder 300 and the purification cylinder 400. A first one-way valve 391 is installed on the transmission pipe 390. The purification cylinder 400 is filled with sodium hydroxide solution. When the first piston plate 330 moves down, ozone and carbon dioxide are transferred to the purification cylinder 400 through the transmission pipe 390, thereby removing carbon dioxide.

[0046] The motor drives the full-tooth gear 320 to reciprocate, causing the first piston plate 330 to move upward, pause, and then move downward, repeating this cycle a set number of times. This ensures that the columnar molecular sieve 370 can remove carbon dioxide and then ozone as much as possible. Each time the first piston plate 330 moves downward, the gas removed by the columnar molecular sieve 370 is transported to the purification cylinder 400 through the transmission pipe 390. The sodium hydroxide solution in the purification cylinder 400 absorbs the carbon dioxide in the gas, greatly reducing the concentration of carbon dioxide in the gas. The remaining ozone remains at the top of the purification cylinder 400. The first one-way valve 391 prevents the sodium hydroxide solution in the purification cylinder 400 from flowing back when the first piston plate 330 moves upward.

[0047] An extraction pipe 410 connects the transfer cylinder 500 and the purification cylinder 400. A second one-way valve 430 is installed on the extraction pipe 410. An ozone supply pipe 120 is connected to the ozone catalytic oxidation reactor 110. A transfer pipe 510 connects the ozone supply pipe 120 and the transfer cylinder 500. A third one-way valve 511 is installed on the transfer pipe 510. A second piston plate 520 is slidably connected inside the transfer cylinder 500. When the second piston plate 520 moves downward, it can extract the gas in the purification cylinder 400. When the second piston plate 520 moves upward, it can transfer the gas to the ozone catalytic oxidation reactor 110.

[0048] When the second piston plate 520 moves down into the transfer cylinder 500, it creates a negative pressure inside the transfer cylinder 500. This negative pressure allows the ozone at the top of the purification cylinder 400 to be drawn into the transfer cylinder 500 through the extraction pipe 410. Subsequently, the second piston plate 520 moves up, causing the ozone in the transfer cylinder 500 to be discharged into the ozone supply pipe 120 through the transfer pipe 510. After mixing with the ozone in the ozone supply pipe 120, the ozone enters the ozone catalytic oxidation reactor 110 to participate in the oxidation reaction again. The second one-way valve 430 and the third one-way valve 511 ensure that the purified ozone can flow unidirectionally to the ozone supply pipe 120.

[0049] Reference Figure 4 There are two purification cylinders 400. Both the extraction pipe 410 and the transfer pipe 390 are T-shaped. The three ports of the transfer pipe 390 are connected to the bottom walls of the two purification cylinders 400 and the bottom wall of the exhaust gas extraction cylinder 300, respectively. The three ports of the extraction pipe 410 are connected to the top walls of the two purification cylinders 400 and the top wall of the transfer cylinder 500, respectively. A return pipe 560 connects the transfer pipe 510 and the section of the transfer pipe 390 connected to the exhaust gas extraction cylinder 300. The connection between the transfer pipe 510 and the return pipe 560... A first three-way valve 561 is provided, a second three-way valve 392 is provided at the T-shaped junction of the transmission pipe 390, and a third three-way valve 420 is provided at the T-shaped junction of the extraction pipe 410. When the downward movement distance of the second piston plate 520 increases, the first three-way valve 561, the second three-way valve 392, and the third three-way valve 420 all operate, so that the transfer cylinder 500 and the tail gas extraction cylinder 300 are connected to another purification cylinder 400, and the transfer cylinder 500 is connected to a section of the transmission pipe 390 connected to the tail gas extraction cylinder 300.

[0050] To prevent the sodium hydroxide solution in the purification cylinder 400 from becoming saturated and reducing its carbon dioxide absorption capacity, two purification cylinders 400 are installed. These two purification cylinders 400 operate alternately, with one in operation and connected to both the transfer cylinder 500 and the purification cylinder 400, while the other is in standby mode. When the position of the second piston plate 520 stabilizes, an increase in its downward movement indicates that the gas entering the transfer cylinder 500 contains carbon dioxide. At this point, the sodium hydroxide solution in the working purification cylinder 400 becomes saturated. The control system then activates the first three-way valve 561, the second three-way valve 392, and the third three-way valve 420, connecting the transfer cylinder 500 and the purification cylinder 400 to the standby purification cylinder 400. The transfer cylinder 500 is connected to the section of the transmission pipe 390 connected to the tail gas extraction cylinder 300 via the transfer pipe 510 and the return pipe 560. Thus, when the second piston plate 520 moves upward, it allows ozone gas containing carbon dioxide to be introduced into the switched purification cylinder 400, enabling the removal of carbon dioxide.

[0051] An inner rod 530 is connected to the upper surface of the second piston plate 520. An outer cylinder 531 is sleeved at the bottom of the inner rod 530. A spring 532 is connected between the inner rod 530 and the outer cylinder 531. A rectangular frame 540 is fixedly connected to the bottom of the outer cylinder 531. A toothed gear 550 is rotatably connected to the inside of the rectangular frame 540. Teeth that mate with the toothed gear 550 are provided on the two inner walls of the rectangular frame 540 in the vertical direction. A bracket 570 is fixedly connected to the bottom of the transfer cylinder 500. The outer cylinder 531 slides through the bracket 570. A displacement sensor 571 for detecting the sliding distance of the outer cylinder 531 is provided on the bracket 570.

[0052] A motor is also connected to the support 100. The output of the motor is connected to a toothed gear 550. This motor drives the toothed gear 550 to rotate unidirectionally. The toothed gear 550 alternately meshes with two sets of teeth in the rectangular frame 540, and there is a state where the toothed gear 550 is not meshing with any teeth. When the toothed gear 550 is meshing with the teeth on one side, it can drive the rectangular frame 540 to move downward. As a result, the rectangular frame 540 pulls the second piston plate 520 downward through the outer cylinder 531, spring 532, and inner rod 530. At this time, the transfer cylinder 500 draws gas from the purification cylinder 400. The downward movement distance of the rectangular frame 540 is relatively long, which can drive the second piston plate 520 to slide close to the bottom of the transfer cylinder 500. After the transfer cylinder 500 draws gas from the purification cylinder 400, a negative pressure state will still appear inside. Then the toothed gear 550 continues to rotate until it is not meshing with any teeth, and the rectangular frame 540 moves up and down. No longer restricted, the negative pressure causes the second piston plate 520 to move upward. At this time, the rectangular frame 540 also moves upward. If the carbon dioxide in the gas is largely absorbed by the sodium hydroxide solution in the purification cylinder 400, the upward movement distance of the second piston plate 520 is larger, and vice versa. That is to say, when a large amount of carbon dioxide is absorbed, the downward movement distance of the second piston plate 520 after stabilization is smaller. If the sodium hydroxide solution is saturated and the gas contains a large amount of carbon dioxide, the downward movement distance of the second piston plate 520 after stabilization is longer. After the position of the second piston plate 520 stabilizes, the position of the outer cylinder 531 also stabilizes. The displacement sensor 571 detects the downward movement distance of the outer cylinder 531 after stabilization. When the downward movement distance of the outer cylinder 531 is longer, the control system controls the first three-way valve 561, the second three-way valve 392 and the third three-way valve 420 to operate, so that the purification cylinder 400 in the standby state becomes the working state.

[0053] In addition, the setting of spring 532 allows the toothed gear 550 to drive the rectangular frame 540 to move upward and the second piston plate 520 to the top position of the transfer cylinder 500. The continued upward movement of the rectangular frame 540 can compress the spring 532, causing the outer cylinder 531 to move upward to the inner rod 530, thereby preventing the toothed gear 550 from getting stuck.

[0054] After the second piston plate 520 moves to the top of its stroke, the first three-way valve 561 operates, restoring the connection between the transfer cylinder 500 and the ozone supply pipe 120, so that the gas after carbon dioxide removal can flow through the transfer pipe 510 into the ozone supply pipe 120 again.

[0055] A third piston plate 210 is slidably connected inside the exhaust gas buffer cylinder 200, and a ring 230 is connected to the top of the exhaust gas buffer cylinder 200. A pressure spring 220 is connected between the ring 230 and the third piston plate 210.

[0056] Because the arc-shaped cylinder 360 rotates intermittently, the exhaust gas enters the exhaust gas buffer cylinder 200 and is stored before being released. When the exhaust gas is stored in the exhaust gas buffer cylinder 200, it can push the third piston plate 210 upward. At this time, the pressure spring 220 is compressed and applies downward pressure to the third piston plate 210. When the arc-shaped cylinder 360 rotates and the columnar molecular sieve 370 is in a horizontal state, the pressure spring 220 pushes the third piston plate 210 downward, so that the exhaust gas passes through the columnar molecular sieve 370 at a higher pressure, ensuring the adsorption effect of the columnar molecular sieve 370 on carbon dioxide and ozone.

[0057] A piston cylinder 470 is fixedly connected to the middle of the ring 230. A piston rod 471 is slidably connected inside the piston cylinder 470 and filled with sodium hydroxide solution. A pressure pipe 472 is fixedly connected to the top of the piston cylinder 470. Two branch pipes 473 are connected to the pressure pipe 472. The two branch pipes 473 are respectively connected to two purification cylinders 400. When the third piston plate 210 moves upward, it can push the piston rod 471 to slide in the piston cylinder 470, thereby increasing the pressure inside the purification cylinder 400.

[0058] During the process of the exhaust gas entering the purification cylinder 400, the columnar molecular sieve 370 is in a vertical state. At this time, the exhaust pipe 240 is closed, and the third piston plate 210 is in an upward state. As a result, the third piston plate 210 pushes the piston rod 471 to slide upward, so that the sodium hydroxide solution stored in the piston cylinder 470 is injected into the purification cylinder 400 in the working state through the branch pipe 473. This increases the pressure inside the purification cylinder 400, promotes the absorption of carbon dioxide by the sodium hydroxide solution, and there is a magnetic attraction between the third piston plate 210 and the piston rod 471. When the third piston plate 210 moves downward, it can pull the piston rod 471 to move downward synchronously, so that the pressure inside the purification cylinder 400 can be restored.

[0059] An electromagnetic three-way valve can be installed at the connection between the two branch pipes 473 and the pressurization pipe 472. This electromagnetic three-way valve is adjusted according to the operating status of the first three-way valve 561, the second three-way valve 392 and the third three-way valve 420, so that the piston cylinder 470 is connected to the purification cylinder 400 in the working state.

[0060] A pressure control pipe 483 is connected to the pressure pipe 472. The end of the pressure control pipe 483 is connected to a pressure control cylinder 480. A fourth piston plate 481 is slidably connected inside the pressure control cylinder 480. A pressure control spring 482 is connected between the fourth piston plate 481 and the end of the pressure control cylinder 480.

[0061] To prevent excessive internal pressure in the purification cylinder 400 during operation, when the pressure inside the purification cylinder 400 exceeds the elastic force of the pressure control spring 482, the sodium hydroxide solution is diverted into the pressure control cylinder 480 through the pressure control tube 483 and pushes the fourth piston plate 481 to move downward against the elastic force of the pressure control spring 482. At this time, the pressure control cylinder 480 stores a portion of the sodium hydroxide solution, thus preventing excessive internal pressure in the purification cylinder 400 during operation.

[0062] Drying cotton 140 or silica gel is installed in both the exhaust pipe 130 and the transfer pipe 510 to absorb the moisture in the exhaust gas. Activated carbon can also be installed in the exhaust pipe 240 or the exhaust pipe 130 to remove organic impurities (VOCs) in the exhaust gas before ozone separation, so as to avoid them competing with ozone for adsorption sites or polluting the columnar molecular sieve 370.

[0063] An ozone selective permeation membrane (such as a fluoropolymer membrane) can also be installed inside the transfer tube 510 to isolate the remaining small amount of carbon dioxide.

[0064] In addition, the columnar molecular sieve 370 can be removed and purged with hot nitrogen (150-200℃) to remove adsorbed carbon dioxide and organic matter. The regeneration cycle is set to eight to twenty-four hours according to the tail gas load. Alternatively, the columnar molecular sieve 370 can be directly replaced.

[0065] The top of the purification cylinder 400 is connected to a pressure stabilizing pipe 440, and the bottom of the side wall is connected to a filling pipe 450 and a discharge pipe 460. When the sodium hydroxide solution is saturated, the valves on the pressure stabilizing pipe 440 and the discharge pipe 460 are opened to discharge the saturated sodium hydroxide solution. Then the valve on the discharge pipe 460 is closed, and the valve on the filling pipe 450 is opened to replenish the sodium hydroxide solution into the purification cylinder 400 through the filling pipe 450. After replenishment, all the aforementioned valves are closed.

[0066] A method for treating pesticide production wastewater, using the pesticide production wastewater treatment device of this embodiment, includes the following steps:

[0067] Set the rotation time interval of the arc-shaped cylinder 360 so that the arc-shaped cylinder 360 reciprocates within a 90-degree range at the set time interval;

[0068] Ozone is introduced into the ozone catalytic oxidation reactor 110 through the ozone supply pipe 120. The tail gas of the ozone catalytic oxidation reactor 110 enters the tail gas buffer cylinder 200. In the initial state, the columnar molecular sieve 370 is in a vertical state. The tail gas gathers in the tail gas buffer cylinder 200 and pushes the third piston plate 210 to move upward and compress the pressure spring 220. After reaching the set time interval, the arc cylinder 360 rotates ninety degrees, so that the columnar molecular sieve 370 is in a horizontal state. The pressure spring 220 applies pressure to the third piston plate 210, so that the tail gas passes through the columnar molecular sieve 370 under pressure. Nitrogen in the tail gas passes through the columnar molecular sieve 370, and carbon dioxide and ozone are adsorbed in the columnar molecular sieve 370.

[0069] After the set time interval is reached again, the arc-shaped cylinder 360 rotates 90 degrees, making the columnar molecular sieve 370 vertical. After the control system detects that the columnar molecular sieve 370 is vertical, it controls the first piston plate 330 to move upward, providing a negative pressure state inside the spherical shell 350, so that carbon dioxide and ozone are desorbed from the columnar molecular sieve 370 and enter the tail gas extraction cylinder 300.

[0070] Set the upward movement distance and time of the first piston plate 330. When the first piston plate 330 moves up to the set distance and is maintained for the set time, the first piston plate 330 moves down and pushes the ozone and carbon dioxide collected in the exhaust gas extraction cylinder 300 into the purification cylinder 400 through the transmission pipe 390.

[0071] The first piston plate 330 is set to move up and down a predetermined distance and for a predetermined number of cycles over a given time period, thereby removing as much ozone and carbon dioxide as possible from the columnar molecular sieve 370.

[0072] When ozone and carbon dioxide enter the purification cylinder 400, carbon dioxide reacts with the sodium hydroxide solution inside the purification cylinder 400 and is largely removed, while ozone passes through the sodium hydroxide solution and accumulates at the top of the purification cylinder 400.

[0073] When the columnar molecular sieve 370 is in a vertical state, the exhaust pipe 240 is not connected to the spherical shell 350. At this time, the exhaust gas accumulates in the exhaust gas buffer cylinder 200, causing the third piston plate 210 to move upward. As a result, the third piston plate 210 pushes the piston rod 471 to slide into the piston cylinder 470, allowing the sodium hydroxide solution in the piston cylinder 470 to enter the purification cylinder 400 in the working state, increasing the pressure in the purification cylinder 400 in the working state, and promoting the absorption of carbon dioxide.

[0074] The timing for the downward movement of the second piston plate 520 is set to be the time after the first piston plate 330 stops operating. After the time after the first piston plate 330 stops operating is reached, the second piston plate 520 moves downward and extracts ozone from the purification cylinder 400 through the extraction pipe 410. The downward movement of the second piston plate 520 is the height of the transfer cylinder 500, resulting in a negative pressure state inside the transfer cylinder 500. After the second piston plate 520 moves downward, the downward pulling force applied to the second piston plate 520 is removed, and the negative pressure acts on the second piston plate 520, causing the second piston plate 520 to move upward. After the second piston plate 520 moves upward and its position stabilizes, an upward pushing force is applied to the second piston plate 520, causing the second piston plate 520 to push the ozone in the transfer cylinder 500 through the transfer pipe 510 into the ozone catalytic oxidation reactor 110 for reuse.

[0075] A reference range for the downward movement distance of the outer cylinder 531 is set. When the second piston plate 520 moves downward, the outer cylinder 531 moves downward synchronously. After the position of the second piston plate 520 stabilizes, the position of the outer cylinder 531 also gradually stabilizes. The displacement sensor 571 detects the downward movement distance of the outer cylinder 531 and compares it with the reference range. If the downward movement distance is greater than the reference range, it indicates that the sodium hydroxide solution in the working purification cylinder 400 is saturated with adsorption. The second piston plate 520 continues to move upward. At this time, the first three-way valve 561, the second three-way valve 392, and the third three-way valve 420 are all in operation, so that the transfer cylinder 500 and the tail gas extraction cylinder 300 are connected to another purification cylinder 400. The transfer cylinder 500 is connected to a section of the transmission pipe 390 connected to the tail gas extraction cylinder 300, so that the carbon dioxide that has not been completely adsorbed is introduced into another purification cylinder 400, so that the carbon dioxide is absorbed again.

[0076] After the second piston plate 520 moves to the top of its stroke, the first three-way valve 561 operates, restoring the connection between the transfer cylinder 500 and the ozone supply pipe 120;

[0077] The control system acquires the operating status of the first three-way valve 561, the second three-way valve 392, and the third three-way valve 420. After the first three-way valve 561, the second three-way valve 392, and the third three-way valve 420 operate, and when the second piston plate 520 reciprocates once, the outer cylinder 531 moves downward more than the reference range, the second three-way valve 392 and the third three-way valve 420 maintain their current state.

[0078] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A pesticide production wastewater treatment device, comprising an ozone catalytic oxidation reactor (110), characterized in that: It also includes an exhaust gas buffer tank (200), an exhaust gas extraction tank (300), a purification tank (400), and a transfer tank (500). The exhaust gas buffer tank (200) is connected to the ozone catalytic oxidation reactor (110) for collecting exhaust gas. The exhaust gas extraction tank (300) is connected to the exhaust gas buffer tank (200) for extracting ozone and carbon dioxide. The purification tank (400) is connected to the exhaust gas extraction tank (300) for absorbing carbon dioxide. The transfer tank (500) is connected to the purification tank (400) for transferring ozone to the ozone catalytic oxidation reactor (110). The bottom of the exhaust gas buffer cylinder (200) is connected to an exhaust pipe (240), and a spherical shell (350) is connected to the exhaust pipe (240). An extraction pipe (340) perpendicular to the exhaust pipe (240) is connected between the spherical shell (350) and the exhaust gas extraction cylinder (300). An arc-shaped cylinder (360) is rotatably connected inside the spherical shell (350). A columnar molecular sieve (370) is connected inside the arc-shaped cylinder (360), and its outer wall is attached to the inner wall of the spherical shell (350). A first piston plate (330) is slidably connected inside the exhaust gas extraction cylinder (300). When the columnar molecular sieve (370) is coaxial with the exhaust pipe (240), the exhaust gas flows toward the columnar molecular sieve (370), so that the nitrogen in the exhaust gas passes through the columnar molecular sieve (370) and is discharged, and ozone and carbon dioxide are adsorbed on the columnar molecular sieve (370). When the columnar molecular sieve (370) is coaxial with the extraction pipe (340), the first piston plate (330) moves upward, so that ozone and carbon dioxide are desorbed from the columnar molecular sieve (370).

2. The pesticide production wastewater treatment device according to claim 1, characterized in that: A transmission pipe (390) connects the exhaust gas extraction cylinder (300) and the purification cylinder (400). A first one-way valve (391) is provided on the transmission pipe (390). The purification cylinder (400) is filled with sodium hydroxide solution. When the first piston plate (330) moves down, ozone and carbon dioxide are transferred to the purification cylinder (400) through the transmission pipe (390), thereby removing carbon dioxide.

3. The pesticide production wastewater treatment device according to claim 2, characterized in that: An extraction pipe (410) is connected between the transfer cylinder (500) and the purification cylinder (400). A second one-way valve (430) is provided on the extraction pipe (410). An ozone supply pipe (120) is connected to the ozone catalytic oxidation reactor (110). A transfer pipe (510) is connected between the ozone supply pipe (120) and the transfer cylinder (500). A third one-way valve (511) is provided on the transfer pipe (510). A second piston plate (520) is slidably connected inside the transfer cylinder (500). When the second piston plate (520) moves down, it can extract the gas in the purification cylinder (400). When the second piston plate (520) moves up, it can transfer the gas to the ozone catalytic oxidation reactor (110).

4. The pesticide production wastewater treatment device according to claim 3, characterized in that: There are two purification cylinders (400). The extraction pipe (410) and the transmission pipe (390) are both T-shaped. The three ports of the transmission pipe (390) are respectively connected to the bottom walls of the two purification cylinders (400) and the bottom wall of the exhaust gas extraction cylinder (300). The three ports of the extraction pipe (410) are respectively connected to the top walls of the two purification cylinders (400) and the top wall of the transfer cylinder (500). A return pipe (560) is connected between the transfer pipe (510) and the section of the transmission pipe (390) connected to the exhaust gas extraction cylinder (300). A first three-way valve (561) is provided at the connection between the transfer pipe (510) and the return pipe (560). A second three-way valve (392) is provided at the T-shaped intersection of the transmission pipe (390). A third three-way valve (420) is provided at the T-shaped intersection of the extraction pipe (410). When the downward distance of the second piston plate (520) increases, the first three-way valve (561), the second three-way valve (392) and the third three-way valve (420) all operate, so that the transfer cylinder (500) and the exhaust gas extraction cylinder (300) are connected to another purification cylinder (400), and the transfer cylinder (500) is connected to a section of the transmission pipe (390) connected to the exhaust gas extraction cylinder (300).

5. The pesticide production wastewater treatment device according to claim 4, characterized in that: An inner rod (530) is connected to the upper surface of the second piston plate (520). An outer cylinder (531) is sleeved on the bottom of the inner rod (530). A spring (532) is connected between the inner rod (530) and the outer cylinder (531). A rectangular frame (540) is fixedly connected to the bottom of the outer cylinder (531). A toothed gear (550) is rotatably connected to the inside of the rectangular frame (540) on a fixed axis. Teeth that mate with the toothed gear (550) are provided on the two inner walls of the rectangular frame (540) in the vertical direction. The bottom of the transfer cylinder (500) is fixedly connected to a bracket (570), the outer cylinder (531) slides through the bracket (570), and a displacement sensor (571) is provided on the bracket (570) for detecting the sliding distance of the outer cylinder (531).

6. The pesticide production wastewater treatment device according to claim 5, characterized in that: A third piston plate (210) is slidably connected inside the exhaust gas buffer cylinder (200), and a ring (230) is connected to the top of the exhaust gas buffer cylinder (200). A pressure spring (220) is connected between the ring (230) and the third piston plate (210).

7. The pesticide production wastewater treatment device according to claim 6, characterized in that: A piston cylinder (470) is fixedly connected to the middle of the ring (230). A piston rod (471) is slidably connected inside the piston cylinder (470) and filled with sodium hydroxide solution. A pressure tube (472) is fixedly connected to the top of the piston cylinder (470). Two branch tubes (473) are connected to the pressure tube (472). The two branch tubes (473) are respectively connected to the two purification cylinders (400). When the third piston plate (210) moves upward, it can push the piston rod (471) to slide in the piston cylinder (470), thereby increasing the pressure inside the purification cylinder (400).

8. The pesticide production wastewater treatment device according to claim 7, characterized in that: The pressurizing tube (472) is connected to a pressure control tube (483), and the end of the pressure control tube (483) is connected to a pressure control cylinder (480). A fourth piston plate (481) is slidably connected inside the pressure control cylinder (480), and a pressure control spring (482) is connected between the fourth piston plate (481) and the end of the pressure control cylinder (480).

9. A method for treating pesticide production wastewater, using the pesticide production wastewater treatment device as described in claim 8, characterized in that, Includes the following steps: Set the rotation time interval of the arc-shaped cylinder (360) so that the arc-shaped cylinder (360) reciprocates within a 90-degree range at the set time interval; Ozone is introduced into the ozone catalytic oxidation reactor (110), and the tail gas of the ozone catalytic oxidation reactor (110) enters the tail gas buffer cylinder (200). In the initial state, the columnar molecular sieve (370) is in a vertical state. The tail gas gathers in the tail gas buffer cylinder (200) and pushes the third piston plate (210) to move upward and compress the pressure spring (220). After reaching the set time interval, the arc cylinder (360) rotates ninety degrees, so that the columnar molecular sieve (370) is in a horizontal state. The pressure spring (220) applies pressure to the third piston plate (210), so that the tail gas passes through the columnar molecular sieve (370) under pressure. Nitrogen in the tail gas passes through the columnar molecular sieve (370), and carbon dioxide and ozone are adsorbed on the columnar molecular sieve (370). After the set time interval is reached again, the arc-shaped cylinder (360) rotates ninety degrees, so that the columnar molecular sieve (370) is in a vertical state. After the control system detects that the columnar molecular sieve (370) is in a vertical state, it controls the first piston plate (330) to move upward, providing a negative pressure state inside the spherical shell (350), so that carbon dioxide and ozone are desorbed from the columnar molecular sieve (370) and enter the tail gas extraction cylinder (300); Set the upward movement distance and time of the first piston plate (330). When the first piston plate (330) moves up to the set distance and is maintained for the set time, the first piston plate (330) moves down and pushes the ozone and carbon dioxide collected in the exhaust gas extraction cylinder (300) into the purification cylinder (400) through the transmission pipe (390). The first piston plate (330) is set to move up and down a set distance and time, and the number of cycles is set so that the first piston plate (330) moves up and down a set number of times, thereby removing the ozone and carbon dioxide adsorbed by the columnar molecular sieve (370) as much as possible. When ozone and carbon dioxide enter the purification cylinder (400), carbon dioxide reacts with the sodium hydroxide solution inside the purification cylinder (400) and is largely removed, while ozone passes through the sodium hydroxide solution and accumulates at the top of the purification cylinder (400). When the columnar molecular sieve (370) is in a vertical state, the exhaust pipe (240) is not connected to the spherical shell (350). At this time, the exhaust gas accumulates in the exhaust gas buffer cylinder (200), causing the third piston plate (210) to move upward. As a result, the third piston plate (210) pushes the piston rod (471) to slide into the piston cylinder (470), allowing the sodium hydroxide solution in the piston cylinder (470) to enter the purification cylinder (400) in the working state, increasing the pressure in the purification cylinder (400) in the working state and promoting the absorption of carbon dioxide. The timing for the downward movement of the second piston plate (520) is set to be the time after the first piston plate (330) stops operating. After the time after the first piston plate (330) stops operating is reached, the second piston plate (520) moves downward and extracts ozone from the purification cylinder (400) through the extraction pipe (410). The downward movement of the second piston plate (520) is the height of the transfer cylinder (500), resulting in a negative pressure state inside the transfer cylinder (500). After the second piston plate (520) moves downward, the downward force applied to the second piston plate (520) is removed, and the negative pressure acts on the second piston plate (520), causing the second piston plate (520) to move upward. After the second piston plate (520) moves upward and its position stabilizes, an upward thrust is applied to the second piston plate (520), causing the second piston plate (520) to push the ozone in the transfer cylinder (500) through the transfer pipe (510) into the ozone catalytic oxidation reactor (110) for reuse. Set a reference range for the downward movement distance of the outer cylinder (531). When the second piston plate (520) moves downward, the outer cylinder (531) moves downward synchronously. After the position of the second piston plate (520) stabilizes, the position of the outer cylinder (531) also gradually stabilizes. The displacement sensor (571) detects the downward movement distance of the outer cylinder (531) and compares it with the reference range. If the downward movement distance is greater than the reference range, it indicates that the sodium hydroxide solution in the working purification cylinder (400) is saturated with adsorption. The second piston plate (520) continues to move upward. At this time, the first three-way valve (561), the second three-way valve (392), and the third three-way valve (420) are all in operation, so that the transfer cylinder (500) and the tail gas extraction cylinder (300) are connected to another purification cylinder (400). The transfer cylinder (500) is connected to a section of the transmission pipe (390) connected to the tail gas extraction cylinder (300), so that the carbon dioxide that has not been completely adsorbed is introduced into another purification cylinder (400) and the carbon dioxide is absorbed again. After the second piston plate (520) moves to the top of its stroke, the first three-way valve (561) operates, restoring the connection between the transfer cylinder (500) and the ozone catalytic oxidation reactor (110); The control system acquires the operating status of the first three-way valve (561), the second three-way valve (392), and the third three-way valve (420). After the first three-way valve (561), the second three-way valve (392), and the third three-way valve (420) are in operation, and when the second piston plate (520) reciprocates once, the outer cylinder (531) moves down more than the reference range. The second three-way valve (392) and the third three-way valve (420) maintain their current state.

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