Waste gas treatment device for alkali recovery boiler

Abstract

The invention discloses a waste gas treatment device for an alkali recovery boiler, and belongs to the technical field of waste gas treatment.The waste gas treatment device comprises a gas washing mechanism used for treating waste gas of the alkali recovery boiler, and the gas washing mechanism is provided with a detection mechanism used for detecting the pH value of the waste gas and a switching mechanism used for conducting physical adsorption on the waste gas; the gas washing mechanism firstly carries out gas washing with water to remove water-soluble acid gas in waste gas, then the waste gas is subjected to secondary gas washing with alkali liquor, the gas washing effect is good, and water is prevented from being sucked back into a gas inlet pipe through high-density silicone oil at the bottom of the pretreatment tank; the detection mechanism can detect waste gas after two times of gas washing, so that whether water and alkali liquor in the gas washing mechanism need to be replaced or not is ensured, and the gas washing effect is ensured; the arranged switching mechanism can automatically replace the discharge filter element, the reliability of physical filtration of waste gas is ensured, and the automation degree is high.

Description

Technical Field

[0001] The present invention relates to the technical field of waste gas treatment, and particularly relates to a waste gas treatment device for an alkali recovery boiler. Background Art

[0002] An alkali recovery boiler is a key piece of equipment in the pulp and paper industry. It is specifically designed to recover and treat the alkaline waste liquid generated during the pulp manufacturing process. Its main function is to recover and utilize the alkali in the waste liquid in the pulp industry, thereby reducing environmental pollution, saving energy, improving the utilization rate of resources, and at the same time generating high-pressure steam for power generation or process heat. The waste gas generated by the alkali recovery boiler is mainly acidic. If directly discharged, sulfur dioxide and nitrogen oxides in the acidic waste gas will react with water vapor and oxygen in the air to form sulfuric acid and nitric acid. After these acidic substances fall to the ground, they form acid rain, which has a serious destructive effect on the ecological environment, especially on the soil, water sources, and plants. Moreover, the chemical substances in the acidic waste gas will react with the moisture in the air to form acidic aerosols. These particulate matters will further pollute the air, increase the concentration of fine particulate matter, and affect air quality. Therefore, it is necessary to treat the acidic waste gas before discharging it. The waste gas treatment devices for alkali recovery boilers in the prior art cannot automatically detect whether the treated waste gas is qualified, and cannot automatically replace the physical adsorption filter element. Summary of the Invention

[0003] In view of the above technical problems, the technical solution adopted by the present invention is: a waste gas treatment device for an alkali recovery boiler, including a scrubbing mechanism for treating the waste gas of the alkali recovery boiler. The scrubbing mechanism includes a bottom plate, and a detection mechanism for detecting the pH value of the waste gas and a switching mechanism for physically adsorbing the waste gas are arranged on the scrubbing mechanism; The scrubbing mechanism includes a bracket fixedly installed on the bottom plate. A temporary storage tank and a post-treatment tank are fixedly installed on the bracket. A connecting frame is fixedly installed on the post-treatment tank, and a pre-treatment tank is fixedly installed on the connecting frame. A detection pipe is fixedly installed on the temporary storage tank; The detection mechanism includes a detection tank, and an upper electromagnetic valve is fixedly installed on the detection tank. A docking plate is fixedly installed on the upper electromagnetic valve.

[0004] Further, the scrubbing mechanism further includes an intake pipe fixedly installed on the pre-treatment tank, a water replenishing pipe fixedly installed on the pre-treatment tank, a connecting pipe fixedly installed on the pre-treatment tank. The connecting pipe is fixedly installed with the post-treatment tank. A liquid replenishing pipe is fixedly installed on the post-treatment tank, a temporary storage pipe is fixedly installed on the post-treatment tank. The temporary storage pipe is fixedly installed with the temporary storage tank. The detection pipe is fixedly installed with the detection tank.

[0005] Furthermore, a collection box is fixedly installed on the bottom plate. There are two cavities in the collection box, which are divided into a front cavity and a rear cavity. The connecting frame is fixedly installed with the collection box. A liquid discharge pipe is fixedly installed at the bottom of the pretreatment tank, and a rear liquid discharge pipe is fixedly installed at the bottom of the post-treatment tank. An inlet pipe for the rear medicine, an inlet pipe for the front medicine, a front liquid discharge pipe, and a rear liquid discharge pipe are fixedly installed on the collection box. A back suction pipe is fixedly installed on the collection box. A water pump is fixedly installed in the collection box. The water pump is connected to the back suction pipe, and the back suction pipe is fixedly installed with the pretreatment tank. The liquid discharge pipe, the inlet pipe for the front medicine, the front liquid discharge pipe, the back suction pipe, and the water pump are located in the front cavity of the collection box, and the rear liquid discharge pipe, the inlet pipe for the rear medicine, and the rear liquid discharge pipe are located in the rear cavity of the collection box.

[0006] Furthermore, electromagnetic valves are provided on the water supply pipe, the liquid supply pipe, the rear liquid discharge pipe, the liquid discharge pipe, the inlet pipe for the rear medicine, the inlet pipe for the front medicine, the rear liquid discharge pipe, and the front liquid discharge pipe. A controller is provided on the bottom plate, and all the electromagnetic valves are electrically connected to the controller, and the upper electromagnetic valve is electrically connected to the controller.

[0007] Furthermore, high-density silicone oil is filled at the bottom of the pretreatment tank, water is filled above the high-density silicone oil, the air inlet pipe is inserted into the high-density silicone oil, sodium hydroxide solution is filled in the post-treatment tank, and the connecting pipe is inserted into the sodium hydroxide solution in the post-treatment tank.

[0008] The waste gas from the alkali recovery boiler enters the high-density silicone oil in the pretreatment tank through the air inlet pipe. The high-density silicone oil is used to prevent water from being sucked back into the air inlet pipe. Then the gas enters the water above the high-density silicone oil, and part of the water-soluble acidic waste gas in the waste gas is adsorbed by the water. Then the waste gas enters the sodium hydroxide solution in the post-treatment tank through the connecting pipe, and the acidic waste gas in the waste gas is further neutralized by the sodium hydroxide solution. Then the waste gas enters the temporary storage tank through the temporary storage pipe, and then the waste gas enters the detection tank through the detection pipe. The one-way valve makes the waste gas can only enter the detection tank from the detection pipe, but cannot enter the detection pipe from the detection tank.

[0009] As the amount of acidic gas adsorbed by the water in the pre-treatment tank increases, the water needs to be replaced and replenished. However, the high-density silicone oil can be reused. Similarly, as the acidic waste gas continuously enters the post-treatment tank, the sodium hydroxide solution in the post-treatment tank will gradually be consumed and needs to be replaced and replenished. When replacing the water in the pre-treatment tank, the solenoid valve on the drain pipe is opened, and the water and high-density silicone oil in the pre-treatment tank enter the front cavity of the collection tank. Eventually, the high-density silicone oil will be located at the bottom layer, while the water is at the upper layer. Subsequently, the solenoid valve on the drain pipe is closed, and the solenoid valve on the forward medicine pipe is opened. The external liquid medicine enters and reacts with the acidic substances in the water in the front cavity of the collection tank. Then, the solenoid valve on the front drain pipe is opened, and the reacted water and liquid medicine are discharged together. Since the silicone liquid is located at the lower layer and the front drain pipe is located in the middle of the collection tank, the front drain pipe will not discharge the high-density silicone oil. The water pump pumps the high-density silicone oil from the back suction pipe into the pre-treatment tank, and the solenoid valve on the water replenishing pipe is opened to replenish water into the pre-treatment tank. The water is located above the high-density silicone oil. When replacing the sodium hydroxide solution in the post-treatment tank, the solenoid valve on the rear drain pipe is opened, and the sodium hydroxide solution in the post-treatment tank enters the rear cavity of the collection tank. The solenoid valve on the rear medicine pipe is opened to allow the liquid medicine to enter the rear cavity of the collection tank and react with the sodium hydroxide solution. Then, the solenoid valve on the rear drain pipe is opened to discharge the liquid in the rear cavity of the collection tank. The solenoid valve on the liquid replenishing pipe is opened to replenish the sodium hydroxide solution into the post-treatment tank.

[0010] Further, the detection mechanism further includes a detection bracket fixedly installed on the temporary storage tank. The detection tank is fixedly installed with the temporary storage tank. The detection tank is filled with a spiropyran solution. The detection tank is provided with a transparent part. A light source and a color plate are fixedly installed on the detection bracket. The light source and the color plate are located beside the transparent part of the detection tank. A one-way valve is fixedly installed on the detection pipe. The one-way valve is fixedly installed at the bottom of the detection tank.

[0011] Further, an alkali tank is fixedly installed on the detection bracket. A replenishing pipe is fixedly installed on the alkali tank. A dosing one-way valve is fixedly installed below the detection tank. A push-out pipe is fixedly installed on the dosing one-way valve. A push cylinder is fixedly installed on the push-out pipe. An agent outlet one-way valve is fixedly installed at the bottom of the alkali tank. The push cylinder is fixedly installed with the agent outlet one-way valve.

[0012] Further, a cylinder frame is fixedly installed on the push cylinder. An electric cylinder is fixedly installed on the cylinder frame. A sliding column is slidably installed on the cylinder frame. A movable frame is fixedly installed on the sliding column. The movable frame is fixedly installed on the output end of the electric cylinder. A sliding column spring is arranged between the movable frame and the cylinder frame. A piston rod and an inner push frame are fixedly installed on the movable frame. An inner push plate is fixedly installed on the piston rod. The inner push plate slides in the push cylinder. A side column is slidably installed on the detection bracket. A heating plate is fixedly installed on the side column. A side column spring is arranged between the side column and the detection bracket. The inner push frame is slidably installed with the side column.

[0013] The exhaust gas entering the detection tank reacts with the spiropyran in the detection tank. The spiropyran is irradiated by a light source. If the color plate shows red, it means that the water in the pre-treatment tank and the sodium hydroxide solution in the post-treatment tank need to be replaced. The gas then enters the docking plate and is discharged after being filtered through the discharge filter element.

[0014] When the alkali liquid in the alkali tank is insufficient, it is replenished through the replenishing pipe.

[0015] Furthermore, the switching mechanism includes an upper frame fixedly mounted on the base plate, an upper frame fixedly mounted on the upper frame, an upper electric cylinder fixedly mounted on the upper frame, a lifting frame fixedly mounted on the output end of the upper electric cylinder, a rack fixedly mounted on the lifting frame, the lifting frame and the upper frame are slidably mounted, two inner rollers are rotatably mounted on the upper frame, a transmission belt is wrapped around the two inner rollers, a number of toggle rods are provided on the transmission belt, a one-way gear is rotatably mounted on the upper frame, an inner gear ring is fixedly mounted on the one-way gear, the inner gear ring is provided with inner teeth, a one-way rotating tooth is rotatably mounted on the inner roller located on the inner side of the one-way gear, a torsion spring is provided between the one-way rotating tooth and the inner roller, the one-way rotating tooth cooperates with the inner teeth of the inner gear ring, and a number of discharge filter elements are slidably mounted in the upper frame.

[0016] Furthermore, a column is fixedly installed below the upper frame, a lower plate is fixedly installed below the column, a lower pressing block is slidably installed on the column, and a column spring is provided between the lower pressing block and the lower plate.

[0017] When the discharge filter element needs to be replaced, the upper solenoid valve is closed, and the upper electric cylinder contracts first, driving the lifting frame and the rack to rise. The lifting frame rises, causing the column spring that was originally in a compressed state to rebound, causing the lower pressure block to rise along the column. The lower pressure block drives the discharge filter element to rise, and the discharge filter element reaches the upper frame. When the rack rises to contact with the one-way gear, it drives the one-way gear and the inner gear ring to rotate counterclockwise. At this time, the inner teeth of the inner gear ring contact with the one-way rotating gear, which will compress the torsion spring between the one-way rotating gear and the inner roller. At this time, the inner roller will not rotate, and then the power is turned on. The cylinder extends, driving the lifting frame and rack to descend. The descending rack drives the one-way gear and the inner gear ring to rotate clockwise, thereby driving the one-way rotating gear and the inner roller to rotate through the inner gear ring, driving the transmission belt to rotate, thereby pushing the used discharge filter element away from the top of the lower pressure block through the toggle rod, and the next unused discharge filter element reaches the top of the lower pressure block. Then the rack disengages from the one-way gear, and the lifting frame continues to descend for a while and contacts the lower pressure block, driving the lower pressure block to descend. The column spring is compressed, so that the discharge filter element fits with the docking plate, completing the replacement of the discharge filter element.

[0018] Compared with the prior art, the present invention has the following advantages: (1) the scrubbing mechanism provided in the present invention first scrubs the exhaust gas with water to remove water-soluble acidic gases in the exhaust gas, and then scrubs the exhaust gas with alkaline solution for a second time, which has a good scrubbing effect and prevents water from being sucked back into the intake pipe through the high-density silicone oil at the bottom of the pre-treatment tank; (2) the detection mechanism provided in the present invention can detect the exhaust gas after two scrubbings to ensure whether the water and alkaline solution in the scrubbing mechanism need to be replaced to ensure the scrubbing effect; (3) the switching mechanism provided in the present invention can replace the exhaust filter element to ensure the reliability of physical filtration of the exhaust gas. At the same time, each time the upper electric cylinder is extended, it drives the exhaust filter element on the upper shelf forward once, and presses the replaced forward filter element onto the docking plate, which has a high degree of automation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0020] Figure 2 Schematic diagram of the gas washing mechanism structure of the present invention Figure 1 .

[0021] Figure 3 Schematic diagram of the gas washing mechanism structure of the present invention Figure 2 .

[0022] Figure 4 Schematic diagram of the gas washing mechanism structure of the present invention Figure 3 .

[0023] Figure 5 Schematic diagram of the detection mechanism structure of the present invention Figure 1 .

[0024] Figure 6Schematic diagram of the detection mechanism structure of the present invention Figure 2 .

[0025] Figure 7 Schematic diagram of the detection mechanism structure of the present invention Figure 3 .

[0026] Figure 8 Schematic diagram of the switching mechanism structure of the present invention Figure 1 .

[0027] Figure 9 Schematic diagram of the switching mechanism structure of the present invention Figure 2 .

[0028] Figure 10 Schematic diagram of the switching mechanism structure of the present invention Figure 3 .

[0029] Figure numbers: 101-base plate; 102-collection box; 103-bracket; 104-temporary storage tank; 105-detection tube; 106-temporary storage tube; 107-post-treatment tank; 108-pre-treatment tank; 109-inlet pipe; 110-connecting frame; 111-return pipe; 112-water supply pipe; 113-drain pipe; 114-connecting pipe; 115-fluid supply pipe; 116-rear drain pipe; 117-rear drug supply pipe; 118-front drug supply pipe; 119-rear drain pipe; 120-water pump; 121-front drain pipe; 201-detection tank; 202-upper solenoid valve; 203-detection bracket; 204-light source; 205-color plate; 206-alkali tank; 207-supply pipe; 208-lower one-way valve; 209-discharge one-way valve Valve; 210- one-way valve for inlet; 211- heating plate; 212- side column; 213- side column spring; 214- inner push frame; 215- electric cylinder; 216- push cylinder; 217- electric cylinder frame; 218- movable frame; 219- slide column; 220- slide column spring; 221- piston rod; 222- inner push plate; 223- ejection tube; 224- docking plate; 301- upper frame; 302- upper frame; 303- upper electric cylinder; 304- lifting frame; 305- rack; 306- one-way gear; 307- inner roller; 308- one-way rotating gear; 309- inner gear ring; 310- transmission belt; 311- toggle lever; 312- lower pressure block; 313- discharge filter element; 314- column; 315- column spring; 316- lower plate. DETAILED DESCRIPTION

[0030] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0031] Example: Reference Figures 1 - 10, An exhaust gas treatment device for an alkali recovery boiler, comprising a gas scrubbing mechanism for treating the exhaust gas of the alkali recovery boiler. The gas scrubbing mechanism includes a bottom plate 101, and a detection mechanism for detecting the pH value of the exhaust gas and a switching mechanism for physically adsorbing the exhaust gas are arranged on the gas scrubbing mechanism; The gas scrubbing mechanism includes a bracket 103 fixedly installed on the bottom plate 101. A temporary storage tank 104 and a post-treatment tank 107 are fixedly installed on the bracket 103. A connecting frame 110 is fixedly installed on the post-treatment tank 107, and a pre-treatment tank 108 is fixedly installed on the connecting frame 110. A detection tube 105 is fixedly installed on the temporary storage tank 104; The detection mechanism includes a detection tank 201. An upper solenoid valve 202 is fixedly installed on the detection tank 201, and a docking plate 224 is fixedly installed on the upper solenoid valve 202.

[0032] As Figures 2 - 4 shown, the gas scrubbing mechanism further includes an intake pipe 109 fixedly installed on the pre-treatment tank 108. A water replenishing pipe 112 is fixedly installed on the pre-treatment tank 108. A connecting pipe 114 is fixedly installed on the pre-treatment tank 108. The connecting pipe 114 is fixedly installed with the post-treatment tank 107. A liquid replenishing pipe 115 is fixedly installed on the post-treatment tank 107. A temporary storage pipe 106 is fixedly installed on the post-treatment tank 107. The temporary storage pipe 106 is fixedly installed with the temporary storage tank 104. The detection tube 105 is fixedly installed with the detection tank 201.

[0033] As Figures 2 - 4 shown, a collection box 102 is fixedly installed on the bottom plate 101. There are two cavities in the collection box 102, which are divided into a front cavity and a rear cavity. The connecting frame 110 is fixedly installed with the collection box 102. A liquid discharge pipe 113 is fixedly installed at the bottom of the pre-treatment tank 108. A rear liquid discharge pipe 116 is fixedly installed at the bottom of the post-treatment tank 107. A rear medicine inlet pipe 117, a front medicine inlet pipe 118, a front drain pipe 121 and a rear drain pipe 119 are fixedly installed on the collection box 102. A back suction pipe 111 is fixedly installed on the collection box 102. A water pump 120 is fixedly installed in the collection box 102. The water pump 120 is connected to the back suction pipe 111. The back suction pipe 111 is fixedly installed with the pre-treatment tank 108. The liquid discharge pipe 113, the front medicine inlet pipe 118, the front drain pipe 121, the back suction pipe 111 and the water pump 120 are located in the front cavity of the collection box 102. The rear liquid discharge pipe 116, the rear medicine inlet pipe 117 and the rear drain pipe 119 are located in the rear cavity of the collection box 102.

[0034] As Figures 2 - 4 shown, solenoid valves are arranged on the water replenishing pipe 112, the liquid replenishing pipe 115, the rear liquid discharge pipe 116, the liquid discharge pipe 113, the rear medicine inlet pipe 117, the front medicine inlet pipe 118, the rear drain pipe 119 and the front drain pipe 121. A controller is arranged on the bottom plate 101. All solenoid valves are electrically connected to the controller, and the upper solenoid valve 202 is electrically connected to the controller.

[0035] As shown Figures 2 - 4 in the figure, high-density silicone oil is installed at the bottom of the pretreatment tank 108, water is installed above the high-density silicone oil, the inlet pipe 109 is inserted into the high-density silicone oil, sodium hydroxide solution is installed in the post-treatment tank 107, and the connecting pipe 114 is inserted into the sodium hydroxide solution in the post-treatment tank 107.

[0036] The waste gas from the alkali recovery boiler enters the high-density silicone oil in the pretreatment tank 108 through the inlet pipe 109. The high-density silicone oil is used to prevent water from being sucked back into the inlet pipe 109. Subsequently, the gas enters the water above the high-density silicone oil, and part of the water-soluble acidic waste gas in the waste gas is adsorbed by the water. Subsequently, the waste gas enters the sodium hydroxide solution in the post-treatment tank 107 through the connecting pipe 114, and the acidic waste gas in the waste gas is further neutralized by the sodium hydroxide solution. Subsequently, the waste gas enters the storage tank 104 through the storage pipe 106, and then the waste gas enters the detection tank 201 from the detection pipe 105. The one-way valve 208 makes the waste gas can only enter the detection tank 201 from the detection pipe 105, but cannot enter the detection pipe 105 from the detection tank 201.

[0037] As the amount of acidic gas adsorbed by the water in the pretreatment tank 108 increases, the water needs to be replaced and replenished, but the high-density silicone oil can be reused. Similarly, as the acidic waste gas continuously enters the post-treatment tank 107, the sodium hydroxide solution in the post-treatment tank 107 will gradually be consumed, and the sodium hydroxide solution needs to be replaced and replenished. When replacing the water in the pretreatment tank 108, the solenoid valve on the drain pipe 113 is opened, and the water and high-density silicone oil in the pretreatment tank 108 enter the front cavity of the collection box 102. The high-density silicone oil will finally be located at the bottom layer, while the water is located at the upper layer. Subsequently, the solenoid valve on the drain pipe 116 is closed, and the solenoid valve on the forward medicine pipe 118 is opened. The external liquid medicine enters and reacts with the acidic substances in the water in the front cavity of the collection box 102. Subsequently, the solenoid valve on the front drain pipe 121 is opened, and the reacted water and liquid medicine are discharged together. Since the silicone liquid is located at the lower layer, and the front drain pipe 121 is located in the middle of the collection box 102, the front drain pipe 121 will not discharge the high-density silicone oil. The water pump 120 pumps the high-density silicone oil from the back suction pipe 111 into the pretreatment tank 108, and the solenoid valve on the water replenishing pipe 112 is opened to replenish water into the pretreatment tank 108. The water is located above the high-density silicone oil. When replacing the sodium hydroxide solution in the post-treatment tank 107, the solenoid valve on the rear drain pipe 116 is opened, and the sodium hydroxide solution in the post-treatment tank 107 enters the rear cavity of the collection box 102. The solenoid valve on the rear medicine pipe 117 is opened, so that the liquid medicine enters the rear cavity of the collection box 102 and reacts with the sodium hydroxide solution. Subsequently, the solenoid valve on the rear drain pipe 119 is opened to discharge the liquid in the rear cavity of the collection box 102, and the solenoid valve on the liquid replenishing pipe 115 is opened to replenish the sodium hydroxide solution into the post-treatment tank 107.

[0038] As Figures 5 - 7 shown, the detection mechanism further includes a detection bracket 203 fixedly installed on the temporary storage tank 104. The detection tank 201 is fixedly installed with the temporary storage tank 104. The detection tank 201 is filled with a spiropyran solution. The detection tank 201 is provided with a transparent part. A light source 204 and a color plate 205 are fixedly installed on the detection bracket 203. The light source 204 and the color plate 205 are located beside the transparent part of the detection tank 201. A one-way valve 208 is fixedly installed on the detection pipe 105. The one-way valve 208 is fixedly installed at the bottom of the detection tank 201.

[0039] As Figures 5 - 7 shown, an alkali tank 206 is fixedly installed on the detection bracket 203. A replenishing pipe 207 is fixedly installed on the alkali tank 206. An inlet agent one-way valve 210 is fixedly installed below the detection tank 201. A push-out pipe 223 is fixedly installed on the inlet agent one-way valve 210. A push cylinder 216 is fixedly installed on the push-out pipe 223. An outlet agent one-way valve 209 is fixedly installed at the bottom of the alkali tank 206. The push cylinder 216 is fixedly installed with the outlet agent one-way valve 209.

[0040] As Figures 5 - 7 shown, an electric cylinder frame 217 is fixedly installed on the push cylinder 216. An electric cylinder 215 is fixedly installed on the electric cylinder frame 217. A sliding column 219 is slidably installed on the electric cylinder frame 217. A movable frame 218 is fixedly installed on the sliding column 219. The movable frame 218 is fixedly installed on the output end of the electric cylinder 215. A sliding column spring 220 is arranged between the movable frame 218 and the electric cylinder frame 217. A piston rod 221 and an inner push frame 214 are fixedly installed on the movable frame 218. An inner push plate 222 is fixedly installed on the piston rod 221. The inner push plate 222 slides inside the push cylinder 216. A side column 212 is slidably installed on the detection bracket 203. A heating plate 211 is fixedly installed on the side column 212. A side column spring 213 is arranged between the side column 212 and the detection bracket 203. The inner push frame 214 is slidably installed with the side column 212.

[0041] The waste gas entering the detection tank 201 reacts with the spiropyran in the detection tank 201. Then the gas enters the docking plate 224 and is discharged after being filtered by the discharge filter element 313. By irradiating the spiropyran with the light source 204, if the color plate 205 shows red, it means that the acidity of the waste gas is strong, and the water in the pretreatment tank 108 and the sodium hydroxide solution in the post-treatment tank 107 need to be replaced.

[0042] When the spiropyran in the detection tank 201 turns red, the spiropyran needs to be reduced with alkali for the next use. The electric cylinder 215 contracts, driving the movable frame 218 and the sliding column 219 to slide inward, and the sliding column spring 220 is compressed, thereby driving the inner push plate 222 to slide in the push cylinder 216 through the piston rod 221. When the inner push plate 222 slides toward the push tube 223, the discharging check valve 209 is closed, and the inlet check valve 210 is opened. The inner push plate 222 pushes the alkali solution in the push cylinder 216 into the detection tank 201 through the push tube 223. At the same time, when the inner push frame 214 slides inward, it pushes the side column 212 and the heating plate 211 to slide toward the detection tank 201, and the side column spring The spring 213 is compressed, so that the heating plate 211 contacts the detection tank 201, and the detection tank 201 is heated by the heating plate 211. Through the heating and the addition of alkali solution, the spiropyran in the detection tank 201 is reduced to colorless. Then the electric cylinder 215 extends, driving the movable frame 218, the piston rod 221 and the inner push plate 222 to slide in the direction away from the push tube 223, so that the inlet check valve 210 is closed and the outlet check valve 209 is opened, and the alkali solution in the alkali tank 206 enters the push cylinder 216. At the same time, the side column spring 213 is reset, and the heating plate 211 is away from the detection tank 201. When the alkali solution in the alkali tank 206 is insufficient, it is replenished through the replenishing pipe 207.

[0043] like Figures 8 - 10 As shown, the switching mechanism includes an upper frame 301 fixedly mounted on the bottom plate 101, an upper frame 302 fixedly mounted on the upper frame 301, an upper electric cylinder 303 fixedly mounted on the upper electric cylinder 303, a lifting frame 304 fixedly mounted on the output end of the upper electric cylinder 303, a rack 305 fixedly mounted on the lifting frame 304, the lifting frame 304 and the upper frame 302 are slidably mounted, two inner rollers 307 are rotatably mounted on the upper frame 301, and a transmission belt 310 is wrapped around the two inner rollers 307. Several toggle rods 311 are provided on the belt 310, a one-way gear 306 is rotatably installed on the upper frame 301, an inner gear ring 309 is fixedly installed on the one-way gear 306, the inner gear ring 309 is provided with inner teeth, a one-way rotating tooth 308 is rotatably installed on the inner roller 307 located on the inner side of the one-way gear 306, a torsion spring is provided between the one-way rotating tooth 308 and the inner roller 307, the one-way rotating tooth 308 cooperates with the inner teeth of the inner gear ring 309, and several discharge filter elements 313 are slidably installed in the upper frame 301.

[0044] like Figures 8 - 10 As shown, a column 314 is fixedly installed below the upper frame 301, a lower plate 316 is fixedly installed below the column 314, a lower pressing block 312 is slidably installed on the column 314, and a column spring 315 is provided between the lower pressing block 312 and the lower plate 316.

[0045] When it is necessary to replace the discharge filter element 313, the upper solenoid valve 202 is closed, and the upper electric cylinder 303 first contracts, driving the lifting frame 304 and the rack 305 to rise. As the lifting frame 304 rises, the column spring 315 that was originally in a compressed state rebounds, causing the lower pressing block 312 to rise along the column 314. The lower pressing block 312 drives the discharge filter element 313 to rise. The discharge filter element 313 reaches inside the upper frame 301. When the rack 305 rises to contact the one-way gear 306, it drives the one-way gear 306 and the internal gear ring 309 to rotate counterclockwise. At this time, the internal teeth of the internal gear ring 309 contact the one-way rotating tooth 308, causing the torsion spring between the one-way rotating tooth 308 and the internal roller 307 to be compressed. At this time, the internal roller 307 does not rotate. Subsequently, the upper electric cylinder 303 extends, driving the lifting frame 304 and the rack 305 to descend. The descent of the rack 305 drives the one-way gear 306 and the internal gear ring 309 to rotate clockwise, thereby driving the one-way rotating tooth 308 and the internal roller 307 to rotate through the internal gear ring 309, driving the transmission belt 310 to rotate, and thereby pushing the used discharge filter element 313 away from above the lower pressing block 312 through the toggle rod 311. The next unused discharge filter element 313 reaches above the lower pressing block 312. Subsequently, the rack 305 disengages from the one-way gear 306. After the lifting frame 304 continues to descend for a period, it contacts the lower pressing block 312, driving the lower pressing block 312 to descend, and the column spring 315 is compressed, causing the discharge filter element 313 to fit with the docking plate 224, completing the replacement of the discharge filter element 313.

[0046] The working principle of an exhaust gas treatment device for an alkali recovery boiler disclosed in the present invention is as follows: The exhaust gas of the alkali recovery boiler enters the high-density silicone oil in the pretreatment tank 108 through the intake pipe 109. The high-density silicone oil is used to prevent water from being sucked back into the intake pipe 109. Subsequently, the gas enters the water above the high-density silicone oil, and part of the water-soluble acidic exhaust gas in the exhaust gas is adsorbed by the water. Subsequently, the exhaust gas enters the sodium hydroxide solution in the post-treatment tank 107 through the connecting pipe 114, and the acidic exhaust gas in the exhaust gas is further neutralized by the sodium hydroxide solution. Subsequently, the exhaust gas enters the storage tank 104 through the storage pipe 106. Subsequently, the exhaust gas enters the detection tank 201 from the detection pipe 105. The one-way valve 208 below allows the exhaust gas to only enter the detection tank 201 from the detection pipe 105 and not enter the detection pipe 105 from the detection tank 201. The exhaust gas entering the detection tank 201 reacts with the spiropyran in the detection tank 201. Subsequently, the gas enters the docking plate 224 and is discharged after being filtered by the discharge filter element 313. By irradiating the spiropyran with the light source 204, if the color plate 205 shows red, it indicates that the water in the pretreatment tank 108 and the sodium hydroxide solution in the post-treatment tank 107 need to be replaced.

[0047] As the amount of acidic gas adsorbed by the water in the pretreatment tank 108 increases, the water needs to be replaced and replenished. However, the high-density silicone oil can be reused. Similarly, as the acidic waste gas continuously enters the post-treatment tank 107, the sodium hydroxide solution in the post-treatment tank 107 will gradually be consumed and needs to be replaced and replenished. When replacing the water in the pretreatment tank 108, the solenoid valve on the drain pipe 113 is opened, and the water and high-density silicone oil in the pretreatment tank 108 enter the front cavity of the collection tank 102. The high-density silicone oil will eventually be located at the bottom layer, while the water is on the upper layer. Subsequently, the solenoid valve on the drain pipe 116 is closed, and the solenoid valve on the forward medicine pipe 118 is opened. The external medicine enters and reacts with the acidic substances in the water in the front cavity of the collection tank 102. Then, the solenoid valve on the front drain pipe 121 is opened, and the reacted water and medicine are discharged together. Since the silicone liquid is located at the lower layer and the front drain pipe 121 is located in the middle of the collection tank 102, the front drain pipe 121 will not discharge the high-density silicone oil. The water pump 120 pumps the high-density silicone oil from the back-drawing pipe 111 into the pretreatment tank 108, and the solenoid valve on the water replenishing pipe 112 is opened to replenish water into the pretreatment tank 108. The water is located above the high-density silicone oil. When replacing the sodium hydroxide solution in the post-treatment tank 107, the solenoid valve on the rear drain pipe 116 is opened, and the sodium hydroxide solution in the post-treatment tank 107 enters the rear cavity of the collection tank 102. The solenoid valve on the rear medicine pipe 117 is opened, allowing the medicine to enter the rear cavity of the collection tank 102 and react with the sodium hydroxide solution. Then, the solenoid valve on the rear drain pipe 119 is opened to discharge the liquid in the rear cavity of the collection tank 102. The solenoid valve on the liquid replenishing pipe 115 is opened to replenish the sodium hydroxide solution into the post-treatment tank 107.When the spiropyran in the detection tank 201 turns red, the spiropyran needs to be reduced with alkali for the next use. The electric cylinder 215 contracts, driving the movable frame 218 and the sliding column 219 to slide inward, and the sliding column spring 220 is compressed, thereby driving the inner push plate 222 to slide in the push cylinder 216 through the piston rod 221. When the inner push plate 222 slides toward the push tube 223, the discharging check valve 209 is closed, and the inlet check valve 210 is opened. The inner push plate 222 pushes the alkali solution in the push cylinder 216 into the detection tank 201 through the push tube 223. At the same time, when the inner push frame 214 slides inward, it pushes the side column 212 and the heating plate 211 to slide toward the detection tank 201. The spring 213 is compressed, so that the heating plate 211 contacts the detection tank 201, and the detection tank 201 is heated by the heating plate 211. The spiropyran in the detection tank 201 is reduced to colorless by the action of the heating and alkali solution. Then the electric cylinder 215 extends, driving the movable frame 218, the piston rod 221 and the inner push plate 222 to slide in the direction away from the push tube 223, so that the inlet one-way valve 210 is closed and the outlet one-way valve 209 is opened. The alkali solution in the alkali tank 206 enters the push cylinder 216. At the same time, the side column spring 213 is reset, and the heating plate 211 is away from the detection tank 201. When the alkali solution in the alkali tank 206 is insufficient, it is replenished through the replenishing pipe 207. When the discharge filter element 313 needs to be replaced, the upper solenoid valve 202 is closed, and the upper electric cylinder 303 contracts first, driving the lifting frame 304 and the rack 305 to rise. The lifting frame 304 rises, causing the column spring 315 that was originally in a compressed state to rebound, causing the lower pressure block 312 to rise along the column 314. The lower pressure block 312 drives the discharge filter element 313 to rise, and the discharge filter element 313 reaches the inside of the upper frame 301. When the rack 305 rises to contact the one-way gear 306, it drives the one-way gear 306 and the inner gear ring 309 to rotate counterclockwise. At this time, the inner teeth of the inner gear ring 309 contact the one-way rotating gear 308, which will compress the torsion spring between the one-way rotating gear 308 and the inner roller 307. At this time, the inner roller 307 will not rotate, and then the upper electric cylinder 30 3 extends, driving the lifting frame 304 and the rack 305 to descend. The descent of the rack 305 drives the one-way gear 306 and the inner gear ring 309 to rotate clockwise, thereby driving the one-way rotating gear 308 and the inner roller 307 to rotate through the inner gear ring 309, driving the transmission belt 310 to rotate, thereby pushing the used discharge filter element 313 away from the top of the lower pressure block 312 through the toggle rod 311, and the next unused discharge filter element 313 reaches the top of the lower pressure block 312. Then the rack 305 disengages from the one-way gear 306, and the lifting frame 304 continues to descend for a while and then contacts the lower pressure block 312, driving the lower pressure block 312 to descend. The column spring 315 is compressed, so that the discharge filter element 313 fits onto the docking plate 224, and the replacement of the discharge filter element 313 is completed.

[0048] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope of the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered within the protection scope of the present invention.

Claims

1. An exhaust gas treatment device for an alkali recovery boiler, comprising a gas scrubbing mechanism for treating the exhaust gas of the alkali recovery boiler, characterized in that: The scrubbing mechanism includes a bottom plate (101), and a detection mechanism for detecting the pH value of the waste gas and a switching mechanism for physically adsorbing the waste gas are arranged on the scrubbing mechanism; The scrubbing mechanism includes a bracket (103) fixedly installed on the bottom plate (101), a temporary storage tank (104) and a post-treatment tank (107) are fixedly installed on the bracket (103), a connecting frame (110) is fixedly installed on the post-treatment tank (107), a pre-treatment tank (108) is fixedly installed on the connecting frame (110), a detection pipe (105) is fixedly installed on the temporary storage tank (104); The detection mechanism includes a detection tank (201), an upper solenoid valve (202) is fixedly installed on the detection tank (201), and a docking plate (224) is fixedly installed on the upper solenoid valve (202).

2. The waste gas treatment device for an alkali recovery boiler according to claim 1, characterized in that: The scrubbing mechanism further includes an air inlet pipe (109) fixedly installed on the pre-treatment tank (108), a water replenishing pipe (112) is fixedly installed on the pre-treatment tank (108), a connecting pipe (114) is fixedly installed on the pre-treatment tank (108), the connecting pipe (114) is fixedly installed with the post-treatment tank (107), a liquid replenishing pipe (115) is fixedly installed on the post-treatment tank (107), a temporary storage pipe (106) is fixedly installed on the post-treatment tank (107), the temporary storage pipe (106) is fixedly installed with the temporary storage tank (104), and the detection pipe (105) is fixedly installed with the detection tank (201).

3. An exhaust gas treatment device for an alkali recovery boiler according to claim 2, characterized in that: A collection box (102) is fixedly installed on the bottom plate (101), there are two cavities in the collection box (102), which are divided into a front cavity and a rear cavity, the connecting frame (110) is fixedly installed with the collection box (102), a liquid discharge pipe (113) is fixedly installed at the bottom of the pre-treatment tank (108), a rear liquid discharge pipe (116) is fixedly installed at the bottom of the post-treatment tank (107), a rear medicine inlet pipe (117), a front medicine inlet pipe (118), a front liquid discharge pipe (121) and a rear liquid discharge pipe (119) are fixedly installed on the collection box (102), a back suction pipe (111) is fixedly installed on the collection box (102), a water pump (120) is fixedly installed in the collection box (102), the water pump (120) is connected with the back suction pipe (111), the back suction pipe (111) is fixedly installed with the pre-treatment tank (108), the liquid discharge pipe (113), the front medicine inlet pipe (118), the front liquid discharge pipe (121), the back suction pipe (111) and the water pump (120) are located in the front cavity of the collection box (102), and the rear liquid discharge pipe (116), the rear medicine inlet pipe (117) and the rear liquid discharge pipe (119) are located in the rear cavity of the collection box (102).

4. An exhaust gas treatment device for an alkali recovery boiler according to claim 3, characterized in that: Solenoid valves are arranged on the water replenishing pipe (112), the liquid replenishing pipe (115), the rear liquid discharge pipe (116), the liquid discharge pipe (113), the rear medicine inlet pipe (117), the front medicine inlet pipe (118), the rear liquid discharge pipe (119) and the front liquid discharge pipe (121), a controller is arranged on the bottom plate (101), all the solenoid valves are electrically connected with the controller, and the upper solenoid valve (202) is electrically connected with the controller.

5. The waste gas treatment device for an alkali recovery boiler according to claim 4, characterized in that: The bottom of the pre-treatment tank (108) is filled with high-density silicone oil, water is filled above the high-density silicone oil, the air inlet pipe (109) is inserted into the high-density silicone oil, the post-treatment tank (107) is filled with sodium hydroxide solution, and the connecting pipe (114) is inserted into the sodium hydroxide solution in the post-treatment tank (107).

6. The waste gas treatment device for an alkali recovery boiler according to claim 1, characterized in that: The detection mechanism further includes a detection bracket (203) fixedly installed on the temporary storage tank (104). The detection tank (201) is fixedly installed with the temporary storage tank (104). The detection tank (201) is filled with a spiropyran solution. The detection tank (201) is provided with a transparent part. A light source (204) and a color plate (205) are fixedly installed on the detection bracket (203). The light source (204) and the color plate (205) are located beside the transparent part of the detection tank (201). A one-way valve (208) is fixedly installed on the detection pipe (105), and the one-way valve (208) is fixedly installed at the bottom of the detection tank (201).

7. An exhaust gas treatment device for an alkali recovery boiler according to claim 6, characterized in that: An alkali tank (206) is fixedly installed on the detection bracket (203). A replenishing pipe (207) is fixedly installed on the alkali tank (206). A one-way valve (210) for injecting agent is fixedly installed below the detection tank (201). A pushing pipe (223) is fixedly installed on the one-way valve (210) for injecting agent. A pushing cylinder (216) is fixedly installed on the pushing pipe (223). A one-way valve (209) for discharging agent is fixedly installed at the bottom of the alkali tank (206). The pushing cylinder (216) is fixedly installed with the one-way valve (209) for discharging agent.

8. An exhaust gas treatment device for an alkali recovery boiler according to claim 7, characterized in that: An electric cylinder bracket (217) is fixedly installed on the pushing cylinder (216). An electric cylinder (215) is fixedly installed on the electric cylinder bracket (217). A sliding column (219) is slidably installed on the electric cylinder bracket (217). A movable bracket (218) is fixedly installed on the sliding column (219). The movable bracket (218) is fixedly installed at the output end of the electric cylinder (215). A sliding column spring (220) is arranged between the movable bracket (218) and the electric cylinder bracket (217). A piston rod (221) and an inner pushing bracket (214) are fixedly installed on the movable bracket (218). An inner pushing plate (222) is fixedly installed on the piston rod (221). The inner pushing plate (222) slides in the pushing cylinder (216). A side column (212) is slidably installed on the detection bracket (203). A heating plate (211) is fixedly installed on the side column (212). A side column spring (213) is arranged between the side column (212) and the detection bracket (203). The inner pushing bracket (214) is slidably installed with the side column (212).

9. An exhaust gas treatment device for an alkali recovery boiler according to claim 1, characterized in that: The switching mechanism comprises an upper frame (301) fixedly mounted on the bottom plate (101), an upper frame (302) fixedly mounted on the upper frame (301), an upper electric cylinder (303) fixedly mounted on the upper frame (302), a lifting frame (304) fixedly mounted on the output end of the upper electric cylinder (303), a rack (305) fixedly mounted on the lifting frame (304), the lifting frame (304) and the upper frame (302) are slidably mounted, two inner rollers (307) are rotatably mounted on the upper frame (301), a transmission belt (310) is wound around the two inner rollers (307), and a transmission belt (310) is driven by the transmission belt. A plurality of toggle rods (311) are provided on the belt (310), a one-way gear (306) is rotatably mounted on the upper frame (301), an inner gear ring (309) is fixedly mounted on the one-way gear (306), the inner gear ring (309) is provided with inner teeth, a one-way rotating gear (308) is rotatably mounted on an inner roller (307) located inside the one-way gear (306), a torsion spring is provided between the one-way rotating gear (308) and the inner roller (307), the one-way rotating gear (308) cooperates with the inner teeth of the inner gear ring (309), and a plurality of discharge filter elements (313) are slidably mounted in the upper frame (301).

10. An exhaust gas treatment device for an alkali recovery boiler according to claim 9, characterized in that: A column (314) is fixedly installed below the upper frame (301), a lower plate (316) is fixedly installed below the column (314), a lower pressing block (312) is slidably installed on the column (314), and a column spring (315) is provided between the lower pressing block (312) and the lower plate (316).

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