A dilute sulfuric acid evaporation and recovery device

Abstract

The present invention relates to the technical field of evaporation equipment, and particularly to a dilute sulfuric acid evaporation and recovery device, which includes a base. A tank body is installed on the base. A liquid injection pipe is connected to the top of the tank body. Two upper and lower circular plates are connected inside the tank body. Connecting holes are spaced apart on both the upper and lower circular plates. Bellows are connected between two corresponding connecting holes above and below. A heater is installed inside the tank body above the upper circular plate. A spiral heat conduction pipe communicated with the liquid injection pipe is installed inside the heater. An installation plate is connected inside the tank body between the upper circular plate and the heater. A rotary liquid distributor communicated with the spiral heat conduction pipe is provided on the installation plate. Through the arrangement of the heater and the spiral heat conduction pipe, preheating of the dilute sulfuric acid solution can be achieved, thereby improving the evaporation efficiency of the dilute sulfuric acid. Through the rotation of the liquid distribution plate, rotary dynamic liquid distribution can be achieved to improve the uniformity of the liquid film distribution, and further improve the evaporation and recovery efficiency of the dilute sulfuric acid.

Description

Technical Field

[0001] The present invention relates to the technical field of evaporation equipment, and particularly to a dilute sulfuric acid evaporation and recovery device. Background Art

[0002] Sulfuric acid is one of the important products in the basic chemical industry. It is not only used as a raw material for many chemical products but also widely applied in multiple industries such as metallurgy, petrochemical, chemical fiber, agricultural fertilizers, and atomic energy. However, during the production and use of sulfuric acid, a large amount of low-concentration dilute sulfuric acid is generated. If these waste acids cannot be properly treated, it will not only cause waste of resources but also exacerbate environmental pollution.

[0003] Traditional methods for treating dilute sulfuric acid mainly involve neutralization with lime or liquid alkali to meet the discharge standards. However, this method generates a large amount of waste residue, increasing production costs and failing to effectively recover sulfuric acid. In addition, traditional heating evaporation processes, such as drum concentration, submerged combustion method, spray evaporation concentration method, etc., although they can obtain sulfuric acid with a higher concentration, due to the need for high temperature and vacuum conditions, they consume a large amount of energy, and sulfuric acid is highly corrosive in a high-temperature environment, easily damaging equipment.

[0004] To solve the above problems, the dilute sulfuric acid evaporation and recovery technology has emerged. This technology mainly removes the water in the dilute sulfuric acid through the evaporation process, thereby increasing the concentration of sulfuric acid and realizing its recycling. Commonly used ones include MVR evaporators, graphite multi-effect evaporators, etc.

[0005] Although the existing MVR evaporators can evaporate and recover dilute sulfuric acid, they have the following deficiencies in practical applications:

[0006] 1. Lack of preheating mechanism: The existing MVR evaporators directly introduce the dilute sulfuric acid solution into the distributor through the liquid injection pipe at the top. Before distributing the dilute sulfuric acid solution to the tube bundle of the distributor, there is a lack of preheating of the dilute sulfuric acid solution, resulting in unsatisfactory evaporation efficiency.

[0007] 2. Uneven liquid film distribution: The existing MVR evaporators use static liquid distribution. The static liquid distribution method is difficult to ensure uniform distribution of the dilute sulfuric acid solution into the tube bundle of the distributor, easily forming local stagnation or overly thick areas, affecting the evaporation and recovery efficiency.

[0008] 3. Uneven heating of the dilute sulfuric acid solution: The tube bundle of the existing MVR evaporators is a vertical circular tube. The vertical circular tube design of the tube bundle not only causes the flow rate of the dilute sulfuric acid solution to be fast, making it difficult to ensure sufficient heating and evaporation, but also makes the part flowing along the tube wall receive more heat, while the middle area receives less heat, resulting in uneven overall heating and affecting the recovery rate of dilute sulfuric acid. Summary of the Invention

[0009] The object of the present invention is to provide a dilute sulfuric acid evaporation and recovery device that can preheat dilute sulfuric acid solution, dynamically distribute the liquid, and ensure that the dilute sulfuric acid solution is uniformly and sufficiently heated to solve the above problems.

[0010] The present invention realizes the above object through the following technical solutions: A dilute sulfuric acid evaporation and recovery device includes a base, on which a tank body is installed. A liquid injection pipe is connected to the top of the tank body. Two upper and lower circular plates are connected inside the tank body. An air outlet pipe is connected to the tank body above the lower circular plate. A drain pipe is connected to the bottom of the tank body. An air-liquid separator is provided on the base, and the air-liquid separator is connected to the tank body through a pipeline, and the pipeline is located below the lower circular plate. Connecting holes are spaced on both the upper and lower circular plates, and corrugated pipes are connected between the two corresponding connecting holes. A heater is installed inside the tank body above the upper circular plate. A spiral heat conduction pipe communicated with the liquid injection pipe is installed inside the heater. An installation plate is connected inside the tank body between the upper circular plate and the heater. A rotary liquid distributor communicated with the spiral heat conduction pipe is provided on the installation plate. An injector one for injecting high-temperature gas between the two circular plates is provided on the tank body.

[0011] Preferably, the wave spacing of the corrugated pipe increases layer by layer from top to bottom.

[0012] Preferably, the rotary liquid distributor includes a rotary seat arranged on the installation plate. A cylinder with an open bottom is connected to the bottom of the rotary seat. The cylinder is rotationally matched with the upper circular plate. A liquid distribution plate is connected inside the cylinder. Liquid distribution holes are spaced on the liquid distribution plate, and the aperture of the liquid distribution holes gradually increases from the center of the liquid distribution plate to the edge. The liquid distribution plate is a conical plate with a higher middle and a lower outer part. A rotary pipe extending into the cylinder is connected to the lower part inside the rotary seat. A connecting seat is rotatably connected to the upper part inside the rotary seat, and the connecting seat is fixedly connected to the bottom of the heater. The liquid outlet end of the spiral heat conduction pipe extends into the connecting seat. A sealing ring is connected inside the connecting seat. The rotary pipe is communicated with the liquid outlet end of the spiral heat conduction pipe through the sealing ring. A driving member for driving the rotary seat to rotate is provided on the installation plate.

[0013] Preferably, the air-liquid separator includes an air-liquid separation tank installed on the base. The air-liquid separation tank is connected to the tank body through a pipeline. An exhaust pipe is connected to the top of the air-liquid separation tank. A wire mesh demister is installed in the upper part inside the air-liquid separation tank. A three-way pipe one is connected to the bottom of the air-liquid separation tank.

[0014] Preferably, a secondary evaporation recovery mechanism is provided on the base, and the secondary evaporation recovery mechanism includes a mounting frame connected to the base, an evaporation tank is installed on the mounting frame, a gas supply pipe is connected to the top of the evaporation tank, the gas supply pipe is connected to the gas-liquid separation tank, a three-way pipe 2 is connected to the bottom of the evaporation tank, the three-way pipe 2 is connected to the three-way pipe 1, the three-way pipe 2 is connected to the discharge pipe through the liquid infusion pipe, an electromagnetic valve 1 is installed on the three-way pipe 1, an electromagnetic valve 2 is installed on the three-way pipe 2, and an electromagnetic valve 3 is installed on the side of the liquid infusion pipe close to the three-way pipe 2, two upper and lower connecting plates are connected in the evaporation tank, a discharge pipe located above the lower connecting plate is connected to the evaporation tank, a tube bundle is connected between the two connecting plates at intervals, and the tube bundle passes through the connecting plates, an injector 2 for injecting high-temperature gas between the two connecting plates is provided on the evaporation tank, a liquid level sensor is installed in the gas-liquid separation tank, and a pH online monitor is installed in the gas-liquid separation tank.

[0015] Preferably, injector 1 includes a guide ring installed on the tank body, a gas injection pipe is connected to the side of the guide ring, and guide plates for guiding high-temperature gas are connected at circumferential intervals inside the guide ring so that the airflow enters the tank body evenly along the guide ring. The structure of injector 2 is consistent with that of injector 1.

[0016] Preferably, a fan is installed in the pipeline, and the fan is connected to a curved pipe extending into the gas-liquid separation tank.

[0017] Preferably, the driving member comprises a motor mounted on the mounting plate, and the output shaft of the motor is transmission-connected to the rotating seat via a gear set.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. By setting up the heater and the spiral heat pipe, the dilute sulfuric acid solution can be preheated, thereby improving the evaporation efficiency of the dilute sulfuric acid.

[0020] 2. Rotation of the liquid distribution plate can realize rotary dynamic liquid distribution, so that the dilute sulfuric acid solution is evenly distributed, avoiding local retention or excessively thick areas, so that the dilute sulfuric acid solution can be evenly distributed in the wave tube, improving the uniformity of liquid distribution, thereby improving the uniformity of film distribution, thereby improving the uniformity of liquid film distribution, and further improving the evaporation recovery efficiency of dilute sulfuric acid.

[0021] 3. The wave tube can not only slow down the flow rate of the dilute sulfuric acid solution, but also extend the flow path of the dilute sulfuric acid solution, ensuring that the dilute sulfuric acid solution is fully heated and evaporated. In addition, the design of the wave tube makes the dilute sulfuric acid solution frequently hit the pipe wall when flowing downward, increasing the contact area between the dilute sulfuric acid solution and the pipe wall, thereby ensuring that the dilute sulfuric acid solution is heated evenly, achieving the effect of ensuring that the dilute sulfuric acid solution is evenly and fully heated, thereby improving the recovery rate of the dilute sulfuric acid.

[0022] 4. The setting of the secondary evaporation recovery mechanism can not only detect whether the liquid after gas-liquid separation meets the requirements, but also perform secondary evaporation recovery on the liquid that does not meet the requirements after gas-liquid separation, so as to further improve the recovery rate of dilute sulfuric acid. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a three-dimensional structural schematic diagram of the present invention.

[0024] Figure 2 It is a partial three-dimensional structural schematic diagram of the present invention.

[0025] Figure 3 It is an installation schematic diagram of the rotary liquid distributor and injector I of the present invention.

[0026] Figure 4 It is a three-dimensional structural schematic diagram of the rotary liquid distributor of the present invention.

[0027] Figure 5 It is a partial three-dimensional structural schematic diagram of the rotary liquid distributor of the present invention.

[0028] Figure 6 It is a three-dimensional structural schematic diagram of injector I of the present invention.

[0029] Figure 7 It is an installation schematic diagram of the secondary evaporation recovery mechanism of the present invention.

[0030] Figure 8 It is a three-dimensional structural schematic diagram of the secondary evaporation recovery mechanism of the present invention.

[0031] In the figure: 1 - base, 2 - tank body, 20 - spiral heat conduction tube, 21 - liquid injection pipe, 22 - air outlet pipe, 23 - pipeline, 24 - liquid discharge pipe, 25 - circular plate, 26 - connection hole, 27 - corrugated pipe, 28 - mounting plate, 29 - heater, 3 - rotary liquid distributor, 31 - rotary seat, 32 - cylinder, 33 - liquid distribution plate, 34 - liquid distribution hole, 35 - rotary pipe, 36 - connection seat, 37 - sealing ring, 38 - motor, 39 - gear set, 4 - injector I, 41 - guide ring, 42 - gas injection pipe, 43 - guide vane, 5 - gas-liquid separator, 50 - gas-liquid separation tank, 51 - exhaust pipe, 52 - wire mesh demister, 53 - tee pipe I, 54 - fan, 55 - elbow pipe, 61 - mounting frame, 62 - evaporation tank, 63 - gas transmission pipe, 64 - tee pipe II, 65 - liquid transmission pipe, 66 - solenoid valve I, 67 - solenoid valve II, 68 - solenoid valve III, 69 - connection disk, 610 - tube bundle, 611 - liquid level sensor, 612 - pH on-line monitor, 613 - injector II, 614 - discharge pipe. DETAILED DESCRIPTION OF THE INVENTION

[0032] The present application will be further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the protection scope of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0033] Refer to Figures 1 - 7 , a dilute sulfuric acid evaporation and recovery device, including a base 1. On the left side of the top of the base 1, a tank body 2 is installed. A liquid injection pipe 21 is connected to the top of the tank body 2. Two upper and lower circular plates 25 are connected inside the tank body 2. An air outlet pipe 22 is connected to the left side of the tank body 2 above the lower circular plate 25. A drain pipe 24 is connected to the bottom of the tank body 2. The inner bottom surface of the tank body 2 is a conical surface that is lower in the middle and higher on the outside to concentrate the liquid and guide it to the drain pipe 24, reducing the liquid residue. In the middle of the top of the base 1, a gas-liquid separator 5 is provided. The gas-liquid separator 5 includes a gas-liquid separation tank 50 installed in the middle of the top of the base 1. An exhaust pipe 51 is connected to the top of the gas-liquid separation tank 50. A wire mesh demister 52 is installed in the upper part of the gas-liquid separation tank 50. A tee pipe 53 is connected to the bottom of the gas-liquid separation tank 50. The inner bottom surface of the gas-liquid separation tank 50 is a conical surface that is lower in the middle and higher on the outside. The gas-liquid separation tank 50 is connected to the tank body 2 through a pipe 23. The pipe 23 is located below the lower circular plate 25 and the wire mesh demister 52. Square connection holes 26 are spaced apart on both the upper and lower circular plates 25. Square corrugated pipes 27 are connected between the two corresponding connection holes 26 up and down. The corrugation spacing of the corrugated pipe 27 increases layer by layer from top to bottom. The corrugation spacing of the corrugated pipe 27 is the spacing of the corrugated structure (that is, the distance from crest to crest). The top surface of the circular plate 25 is a conical surface that is lower in the middle and higher on the outside to guide the liquid to the corrugated pipe 27, enabling the liquid to flow into the corrugated pipe 27 faster, reducing the residence time of the liquid on the circular plate 25, and reducing the liquid residue. A heater 29 is installed inside the tank body 2 above the upper circular plate 25. A spiral heat conduction pipe 20 is installed inside the heater 29. The liquid inlet end of the spiral heat conduction pipe 20 is communicated with the liquid injection pipe 21. An installation plate 28 is connected inside the tank body 2 between the upper circular plate 25 and the heater 29. A rotary liquid distributor 3 is provided on the installation plate 28. The rotary liquid distributor 3 is communicated with the liquid outlet end of the spiral heat conduction pipe 20. An injector 4 for injecting high-temperature gas between the two circular plates 25 is provided on the tank body 2. The injector 4 includes a diversion ring 41 installed on the tank body 2. The diversion ring 41 is communicated with the tank body 2. The diversion ring 41 is flush with the upper circular plate 25. An air injection pipe 42 is connected to the side surface of the diversion ring 41. The inner top surface of the diversion ring 41 is designed as an inclined surface to divert the high-temperature gas downward. Diversion vanes 43 for diverting the high-temperature gas are connected along the circumferential direction inside the diversion ring 41 to enable the air flow to uniformly enter the tank body 2 along the diversion ring 41, so that the high-temperature gas can uniformly flow from top to bottom, improving the heating efficiency and heating uniformity of the corrugated pipe 27.

[0034] Refer toFigures 3 - 6 The rotary liquid distributor 3 includes a rotary base 31 rotatably arranged in the middle of the mounting plate 28. A cylinder 32 with an open bottom is connected to the bottom of the rotary base 31. An annular sliding groove for guiding the rotation of the cylinder 32 is formed on the upper circular plate 25. A liquid distribution plate 33 is connected inside the cylinder 32. Liquid distribution holes 34 are spaced apart on the liquid distribution plate 33. The aperture of the liquid distribution holes 34 gradually increases from the center to the edge of the liquid distribution plate 33 (the aperture of the liquid distribution hole 34 near the axis of the liquid distribution plate 33 is smaller than that of the liquid distribution hole 34 far from the axis of the liquid distribution plate 33). The liquid distribution plate 33 is a conical plate with a higher middle and a lower outer part. The top of the cylinder 32 is a conical surface with a higher middle and a lower outer part to guide the liquid from the center to the edge and ensure uniform distribution. A rotary tube 35 extending into the cylinder 32 is connected to the lower part inside the rotary base 31. A connecting seat 36 is rotatably connected to the upper part inside the rotary base 31. The connecting seat 36 is fixedly connected to the bottom of the heater 29. The liquid outlet end of the spiral heat-conducting tube 20 extends into the connecting seat 36. A sealing ring 37 is connected inside the connecting seat 36. The sealing ring 37 is slidably sleeved outside the rotary tube 35 and the spiral heat-conducting tube 20. The rotary tube 35 is communicated with the liquid outlet end of the spiral heat-conducting tube 20 through the sealing ring 37 to prevent liquid leakage. A driving member for driving the rotary base 31 to rotate is provided on the mounting plate 28. The driving member includes a motor 38 mounted on the mounting plate 28. The motor 38 is located on the right side of the rotary base 31. The output shaft of the motor 38 is drivingly connected to the rotary base 31 through a gear set 39. The gear set 39 is composed of two gears. The two gears are respectively connected to the outer wall of the rotary base 31 and the output shaft of the motor 38, and the two gears are meshed.

[0035] First, control the heater 29 to work to heat the spiral heat-conducting tube 20. Then, inject the dilute sulfuric acid solution into the spiral heat-conducting tube 20 through the liquid injection tube 21. Heat the dilute sulfuric acid solution through the spiral heat-conducting tube 20 to preheat the dilute sulfuric acid solution, thereby improving the evaporation efficiency of the dilute sulfuric acid. The spiral heat-conducting tube 20 can extend the flow path of the dilute sulfuric acid solution, ensure sufficient preheating of the dilute sulfuric acid solution, and provide a preheating effect. The preheated dilute sulfuric acid solution is discharged into the cylinder 32 through the rotary tube 35 and discharged onto the liquid distribution plate 33. Then, it is discharged downward through the liquid distribution holes 34 on the liquid distribution plate 33 onto the upper circular plate 25, and then enters the corrugated tube 27. The dilute sulfuric acid solution is distributed through the corrugated tube 27 and forms a liquid film flowing downward.

[0036] Control the operation of the motor 38, drive the rotating base 31 to rotate through the gear set 39, thereby driving the cylinder 32, the liquid distribution plate 33 and the rotating pipe 35 to rotate. The rotation of the liquid distribution plate 33 disperses the dilute sulfuric acid solution outward by centrifugal force, so that the dilute sulfuric acid solution is evenly distributed, avoiding local retention or thick areas, so that the dilute sulfuric acid solution can be evenly distributed into the corrugated pipe 27, improving the uniformity of liquid distribution, so as to improve the uniformity of film coating. Since the aperture of the liquid distribution holes 34 gradually increases from the center to the edge of the liquid distribution plate 33 (the aperture of the liquid distribution holes 34 close to the axis of the liquid distribution plate 33 is smaller than that of the liquid distribution holes 34 far from the axis of the liquid distribution plate 33), the dilute sulfuric acid solution can be more evenly distributed, further improving the uniformity of liquid distribution, so as to further improve the uniformity of film coating. By improving the uniformity of the liquid film distribution, the evaporation recovery efficiency of dilute sulfuric acid can be improved.

[0037] Inject high-temperature gas between the two circular plates 25 through the injector 1. The high-temperature gas flows downward to heat the corrugated pipe 27, and then the high-temperature gas is discharged from the air outlet pipe 22. Heat the dilute sulfuric acid solution through the corrugated pipe 27, so that the water in the dilute sulfuric acid solution evaporates to obtain a concentrated solution, realizing the evaporation and recovery of dilute sulfuric acid. The concentrated solution is discharged downward from the corrugated pipe 27 to the bottom of the tank body 2, and finally discharged outward through the drain pipe 24. The corrugated pipe 27 can not only delay the flow rate of the dilute sulfuric acid solution, but also extend the flow path of the dilute sulfuric acid solution, ensuring that the dilute sulfuric acid solution is fully heated and evaporated. In addition, the design of the corrugated pipe 27 makes the dilute sulfuric acid solution frequently impact the pipe wall when flowing downward, increasing the contact area between the dilute sulfuric acid solution and the pipe wall, so as to ensure that the dilute sulfuric acid solution is evenly heated, achieving the effect of ensuring that the dilute sulfuric acid solution is evenly and fully heated, and then improving the recovery rate of dilute sulfuric acid. Since the corrugated spacing of the corrugated pipe 27 increases layer by layer from top to bottom, the flow rate of the dilute sulfuric acid solution can be gradually increased, avoiding excessive accumulation of the concentrated solution on the pipe wall, not only ensuring that the dilute sulfuric acid solution is evenly heated during the whole flow process, but also effectively preventing the problems of scaling or blockage caused by too high local concentration.

[0038] The hot mixed gas discharged from the corrugated pipe 27 is discharged into the gas-liquid separation tank 50 through the pipeline 23, then flows upward through the wire mesh demister 52, and finally is discharged from the exhaust pipe 51. Separate the liquid droplets entrained in the gas through the wire mesh demister 52 (the wire mesh demister 52 is an existing technology and will not be elaborated here), preventing the liquid from being discharged together with the gas. Specifically, when the gas containing tiny liquid droplets passes through the wire mesh, these liquid droplets will be captured by the wire mesh and aggregated into larger liquid droplets, and finally fall to the bottom of the gas-liquid separation tank 50 due to gravity, and then are discharged outward through the tee 1 53 to realize gas-liquid separation.

[0039] See Figures 7 - 8A secondary evaporation recovery mechanism is provided on the base 1, and the secondary evaporation recovery mechanism includes a mounting frame 61 connected to the right side of the top of the base 1, an evaporation tank 62 is installed on the mounting frame 61, and a gas supply pipe 63 is connected to the top of the evaporation tank 62, and the gas supply pipe 63 is connected to the gas-liquid separation tank 50. The gas outlet end of the gas supply pipe 63 is located below the wire mesh demister 52, and a three-way pipe 64 is connected to the bottom of the evaporation tank 62. The inner bottom surface of the evaporation tank 62 is a conical surface with a low middle and a high outer surface. The three-way pipe 64 is connected to the three-way pipe 1 53, and the three-way pipe 2 64 is connected to the drainage pipe 24 through the liquid delivery pipe 65. A solenoid valve 1 66 is installed at the liquid outlet end of the rear side of the three-way pipe 1 53, and a solenoid valve 2 67 is installed on the three-way pipe 2 64. The solenoid valve 2 67 is located at the connection between the three-way pipe 2 64 and the three-way pipe 1 53. A solenoid valve three 68 is installed on the side of the infusion tube 65 close to the three-way tube two 64, two upper and lower connecting plates 69 are connected in the evaporator 62, and a discharge pipe 614 located above the lower connecting plate 69 is connected to the right side of the evaporator 62. A tube bundle 610 is connected between the two connecting plates 69 at intervals, and the tube bundle 610 penetrates the connecting plate 69. An injector two 613 for injecting high-temperature gas between the two connecting plates 69 is provided on the evaporator 62. The structure of the injector two 613 is consistent with that of the injector one 4. A liquid level sensor 611 is installed in the gas-liquid separation tank 50, and the liquid level sensor 611 is located below the wire mesh demister 52. A pH online monitor 612 is installed in the gas-liquid separation tank 50, and the pH online monitor 612 is located below the liquid level sensor 611.

[0040] The liquid level height in the gas-liquid separation tank 50 can be monitored in real time by the liquid level sensor 611, and the pH value of the liquid in the gas-liquid separation tank 50 can be monitored in real time by the pH online monitor 612 (the pH online monitor 612 is a prior art and will not be described in detail here). When the pH online monitor 612 detects that the pH value of the liquid reaches a preset value, the pH online monitor 612 sends a signal to the controller (the controller is not shown in the figure, the controller is a prior art and will not be described in detail here). When the liquid level sensor 611 detects that the liquid level reaches a first preset value, the liquid level sensor 611 sends a signal to the controller. After receiving the signal, the controller controls the solenoid valve 1 66 to open, and the liquid (liquid that meets the requirements) in the gas-liquid separation tank 50 with a pH value reaching the preset value is discharged backward. When the liquid level sensor 611 detects that the liquid level is lower than the second preset value, the liquid level sensor 611 sends a signal to the controller. After receiving the signal, the controller controls the solenoid valve 1 66 to close. The above is a mode for discharging the liquid (liquid that meets the requirements) with a pH value reaching the preset value.

[0041] When the pH on-line monitor 612 detects that the pH value of the liquid is less than the preset value (when the pH value is less than 7, it indicates that the liquid has acidic characteristics, and the lower the value, the stronger the acidity), the pH on-line monitor 612 sends a signal to the controller. When the liquid level sensor 611 detects that the liquid level reaches the first preset value, the liquid level sensor 611 sends a signal to the controller. After receiving the signal, the controller first controls the solenoid valve three 68 to open, and discharges the concentrated liquid in the tube bundle 610 into the drain pipe 24 through the infusion pipe 65. Then the controller controls the solenoid valve three 68 to close, and controls the solenoid valve two 67 to open, and discharges the liquid with a pH value less than the preset value (non-conforming liquid) in the gas-liquid separation tank 50 into the evaporation tank 62. The liquid with a pH value less than the preset value (non-conforming liquid) then enters the tube bundle 610. The high-temperature gas is injected between the two connecting plates 69 through the injector two 613. The high-temperature gas flows downward to heat the tube bundle 610, and then the high-temperature gas is discharged from the discharge pipe 614. The liquid with a pH value less than the preset value (non-conforming liquid) is evenly distributed through the tube bundle 610 and flows upward to form a thin film (liquid film) for secondary evaporation recovery to obtain the concentrated liquid. The hot mixed gas flows upward and is transported back to the gas-liquid separation tank 50 through the gas transmission pipe 63. When the liquid level sensor 611 detects that the liquid level is lower than the second preset value, the liquid level sensor 611 sends a signal to the controller, and the controller controls the solenoid valve two 67 to close after receiving the signal. In this way, the device can not only detect whether the liquid after gas-liquid separation meets the requirements, but also perform secondary evaporation recovery on the non-conforming liquid after gas-liquid separation to further improve the recovery rate of dilute sulfuric acid.

[0042] See Figure 7 , a fan 54 is installed in the pipeline 23. A bent pipe 55 extending into the gas-liquid separation tank 50 is connected to the fan 54. When the fan 54 works, it can quickly pump the hot mixed gas located below the lower circular plate 25 into the bent pipe 55, and then the hot mixed gas is discharged into the gas-liquid separation tank 50 through the bent pipe 55. In this way, the hot mixed gas can form a vortex and move upward in the gas-liquid separation tank 50, thereby improving the gas-liquid separation efficiency. Specifically, the vortex helps the liquid droplets in the gas to separate from the gas. The liquid droplets sink due to gravity, and the gas continues to move upward, finally realizing efficient gas-liquid separation.

[0043] The above-described embodiments only represent the preferred embodiments of the present invention, and the description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations, improvements and substitutions can be made, and these all belong to the protection scope of the present invention.

Claims

1. A dilute sulfuric acid evaporation recovery device, comprising a base (1), a tank body (2) is installed on the base (1), a liquid injection pipe (21) is connected to the top of the tank body (2), two upper and lower circular plates (25) are connected inside the tank body (2), an air outlet pipe (22) located above the lower circular plate (25) is connected to the tank body (2), a drain pipe (24) is connected to the bottom of the tank body (2), a gas-liquid separator (5) is provided on the base (1), the gas-liquid separator (5) is communicated with the tank body (2) through a pipeline (23), the pipeline (23) is located below the lower circular plate (25), and it is characterized in that, Both the upper and lower circular plates (25) are provided with connecting holes (26) at intervals. A corrugated pipe (27) is connected between the two corresponding connecting holes (26) above and below. A heater (29) is installed inside the tank body (2) above the upper circular plate (25). A spiral heat conduction pipe (20) communicated with the liquid injection pipe (21) is installed inside the heater (29). An installation plate (28) is connected inside the tank body (2) between the upper circular plate (25) and the heater (29). A rotary liquid distributor (3) communicated with the spiral heat conduction pipe (20) is arranged on the installation plate (28). An injector one (4) for injecting high-temperature gas between the two circular plates (25) is arranged on the tank body (2). The gas-liquid separator (5) includes a gas-liquid separation tank (50) installed on the base (1). The gas-liquid separation tank (50) is communicated with the tank body (2) through a pipeline (23). An exhaust pipe (51) is connected to the top of the gas-liquid separation tank (50). A wire mesh demister (52) is installed in the upper part inside the gas-liquid separation tank (50). A tee one (53) is connected to the bottom of the gas-liquid separation tank (50). A secondary evaporation recovery mechanism is arranged on the base (1). The secondary evaporation recovery mechanism includes an installation frame (61) connected to the base (1). An evaporation tank (62) is installed on the installation frame (61). A gas transmission pipe (63) is connected to the top of the evaporation tank (62). The gas transmission pipe (63) is communicated with the gas-liquid separation tank (50). A tee two (64) is connected to the bottom of the evaporation tank (62). The tee two (64) is communicated with the tee one (53). The tee two (64) is communicated with the drain pipe (24) through an infusion pipe (65). An electromagnetic valve one (66) is installed on the tee one (53). An electromagnetic valve two (67) is installed on the tee two (64). An electromagnetic valve three (68) is installed on the infusion pipe (65) near the tee two (64). Two connecting plates (69) are connected inside the evaporation tank (62) from top to bottom. A discharge pipe (614) is connected to the evaporation tank (62) above the lower connecting plate (69). A tube bundle (610) is connected at intervals between the two connecting plates (69). The tube bundle (610) penetrates through the connecting plates (69). An injector two (613) for injecting high-temperature gas between the two connecting plates (69) is arranged on the evaporation tank (62). A liquid level sensor (611) is installed inside the gas-liquid separation tank (50). A pH on-line monitor (612) is installed inside the gas-liquid separation tank (50).

2. The dilute sulfuric acid evaporation and recovery device according to claim 1, wherein, The wave spacing of the corrugated pipe (27) increases layer by layer from top to bottom.

3. The sulfuric acid evaporation recovery device according to claim 2, characterized in that, The rotary liquid distributor (3) comprises a rotary seat (31) arranged on a mounting plate (28), the bottom of the rotary seat (31) is connected to a cylinder (32) with an open bottom, the cylinder (32) is rotatably matched with the upper circular plate (25), a liquid distribution plate (33) is connected inside the cylinder (32), liquid distribution holes (34) are spaced apart on the liquid distribution plate (33), the aperture of the liquid distribution holes (34) gradually increases from the center to the edge of the liquid distribution plate (33), the liquid distribution plate (33) is a cone plate with a high center and a low outside, and the lower inner portion of the rotary seat (31) is provided with a plurality of liquid distribution holes (34). A rotating tube (35) is connected and extends into the cylinder (32); a connecting seat (36) is rotatably connected to the upper part of the rotating seat (31); the connecting seat (36) is fixedly connected to the bottom of the heater (29); the liquid outlet end of the spiral heat conducting tube (20) extends into the connecting seat (36); a sealing ring (37) is connected to the connecting seat (36); the rotating tube (35) is connected to the liquid outlet end of the spiral heat conducting tube (20) via the sealing ring (37); and a driving member for driving the rotating seat (31) to rotate is provided on the mounting plate (28).

4. The dilute sulfuric acid evaporation and recovery device according to claim 3, characterized in that, The injector 1 (4) comprises a guide ring (41) mounted on the tank body (2), a gas injection pipe (42) being connected to the side of the guide ring (41), and guide plates (43) for guiding high-temperature gas being connected at intervals along the circumferential direction inside the guide ring (41) so that the gas flow evenly enters the tank body (2) along the guide ring (41). The structure of the injector 2 (613) is consistent with that of the injector 1 (4).

5. The dilute sulfuric acid evaporation recovery device according to claim 4, characterized in that, A fan (54) is installed in the pipeline (23), and a curved pipe (55) extending into the gas-liquid separation tank (50) is connected to the fan (54).

6. The dilute sulfuric acid evaporation recovery device according to claim 5, characterized in that, The driving member comprises a motor (38) mounted on the mounting plate (28), and an output shaft of the motor (38) is transmission-connected to the rotating seat (31) via a gear set (39).

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