Dilute sulfuric acid evaporation recovery equipment

Abstract

The invention relates to the technical field of evaporation equipment, in particular to dilute sulfuric acid evaporation recovery equipment which comprises a base, a tank is mounted on the base, a liquid injection pipe is connected to the top of the tank, an upper circular plate and a lower circular plate are connected into the tank, connecting holes are formed in the upper circular plate and the lower circular plate at intervals, and a wavy pipe is connected between every two vertically-corresponding connecting holes. A heater located above the upper side circular plate is installed in the tank body, a spiral heat conduction pipe communicated with the liquid injection pipe is installed in the heater, a mounting plate located between the upper side circular plate and the heater is connected in the tank body, and a rotary liquid distributor communicated with the spiral heat conduction pipe is arranged on the mounting plate. By arranging a heater and a spiral heat conduction pipe, a dilute sulfuric acid solution can be preheated, so that the evaporation efficiency of dilute sulfuric acid is improved; rotary dynamic liquid distribution can be realized through rotation of the liquid distribution disc, so that the distribution uniformity of a liquid film is improved, and the evaporation recovery efficiency of dilute sulphuric acid can be further improved.

Description

Technical Field

[0001] The invention relates to the technical field of evaporation equipment, and in particular to dilute sulfuric acid evaporation recovery equipment. 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 used in many industries such as metallurgy, petrochemicals, chemical fibers, agricultural fertilizers, and atomic energy. However, during the production and use of sulfuric acid, a large amount of low-concentration dilute sulfuric acid will be produced. If these waste acids are not properly handled, it will not only cause a waste of resources, but also aggravate environmental pollution.

[0003] The traditional method of treating dilute sulfuric acid is mainly to neutralize it with lime or liquid alkali to meet the emission standards. However, this method will produce a large amount of waste residue, increase production costs, and fail to achieve effective recovery of sulfuric acid. In addition, although traditional heating evaporation processes, such as drum concentration, immersion combustion, spray evaporation concentration, etc., can obtain higher concentrations of sulfuric acid, they require high temperature and vacuum conditions, consume a lot of energy, and sulfuric acid is highly corrosive in high temperature environments, which can easily damage equipment.

[0004] In order to solve the above problems, dilute sulfuric acid evaporation recovery technology came into being. This technology mainly removes water from dilute sulfuric acid through the evaporation process, thereby increasing the concentration of sulfuric acid and realizing its recovery and reuse. Commonly used ones include MVR evaporator, graphite multi-effect evaporator, etc.

[0005] Although the existing MVR evaporator can evaporate and recover dilute sulfuric acid, it has the following shortcomings in practical applications: 1. Lack of preheating mechanism: The existing MVR evaporator directly introduces the dilute sulfuric acid solution into the distributor through the injection pipe on 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.

[0006] 2. Uneven distribution of liquid film: The existing MVR evaporator uses static liquid distribution. The static liquid distribution method is difficult to ensure that the dilute sulfuric acid solution is evenly distributed in the tube bundle of the distributor, which is prone to form local retention or excessively thick areas, affecting the evaporation recovery efficiency.

[0007] 3. Uneven heating of dilute sulfuric acid solution: The existing MVR evaporator has a vertical circular tube bundle. The vertical circular tube bundle not only causes the dilute sulfuric acid solution to flow quickly, making it difficult to ensure sufficient heating and evaporation, but also causes the part flowing along the tube wall to be heated more, while the middle area is heated less, resulting in uneven overall heating and affecting the recovery rate of dilute sulfuric acid. Summary of the invention

[0008] The object of the present invention is to provide a dilute sulfuric acid evaporation and recovery device which can preheat the dilute sulfuric acid solution, dynamically distribute the solution, and ensure that the dilute sulfuric acid solution is evenly and fully heated in order to solve the above problems.

[0009] The present invention achieves the above-mentioned purpose through the following technical scheme: a dilute sulfuric acid evaporation and recovery equipment, including a base, a tank body is installed on the base, a liquid injection pipe is connected to the top of the tank body, an upper and lower circular plates are connected to the tank body, an air outlet pipe located above the lower circular plate is connected to the tank body, a liquid discharge pipe is connected to the bottom of the tank body, a gas-liquid separator is provided on the base, the gas-liquid separator is connected to the tank body through a pipeline, the pipeline is located below the lower circular plate, the upper and lower circular plates are spaced apart with connecting holes, a wave pipe is connected between the two corresponding upper and lower connecting holes, a heater located above the upper circular plate is installed in the tank body, a spiral heat conduction pipe connected to the liquid injection pipe is installed in the heater, a mounting plate located between the upper circular plate and the heater is connected in the tank body, a rotary liquid distributor connected to the spiral heat conduction pipe is provided on the mounting plate, and an injector 1 for injecting high-temperature gas between the two circular plates is provided on the tank body.

[0010] Preferably, the wave spacing of the wave tube increases layer by layer from top to bottom.

[0011] Preferably, the rotary liquid distributor includes a rotating seat arranged on a mounting plate, a cylinder with an open bottom connected to the bottom of the rotating seat, the cylinder rotatably cooperates with the upper circular plate, a liquid distribution pan is connected inside the cylinder, liquid distribution holes are spaced apart on the liquid distribution pan, the aperture of the liquid distribution holes gradually increases from the center to the edge of the liquid distribution pan, the liquid distribution pan is a conical pan with a high middle and a low outside, a rotating tube extending into the cylinder is connected to the lower inner part of the rotating seat, a connecting seat is rotatably connected to the upper inner part of the rotating seat, the connecting seat is fixedly connected to the bottom of the heater, the liquid outlet end of the spiral heat conducting pipe extends into the connecting seat, a sealing ring is connected inside the connecting seat, the rotating tube is connected to the liquid outlet end of the spiral heat conducting pipe through the sealing ring, and a driving member for driving the rotating seat to rotate is provided on the mounting plate.

[0012] Preferably, the gas-liquid separator includes a gas-liquid separation tank installed on the base, the gas-liquid separation tank is connected to the tank body through a pipeline, the top of the gas-liquid separation tank is connected to an exhaust pipe, a wire mesh demister is installed in the upper part of the gas-liquid separation tank, and the bottom of the gas-liquid separation tank is connected to a three-way pipe.

[0013] 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.

[0014] 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.

[0015] Preferably, a fan is installed in the pipeline, and the fan is connected to a curved pipe extending into the gas-liquid separation tank.

[0016] 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.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 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.

[0018] 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.

[0019] 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.

[0020] 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 a second 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

[0021] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention.

[0022] Figure 2 It is a partial three-dimensional structural schematic diagram of the present invention.

[0023] Figure 3 It is a schematic diagram of the installation of the rotary liquid distributor and injector of the present invention.

[0024] Figure 4 It is a schematic diagram of the three-dimensional structure of the rotary liquid distributor of the present invention.

[0025] Figure 5 It is a partial three-dimensional structural schematic diagram of the rotary liquid distributor of the present invention.

[0026] Figure 6 It is a schematic diagram of the three-dimensional structure of the injector 1 of the present invention.

[0027] Figure 7 It is a schematic diagram of the installation of the secondary evaporation recovery mechanism of the present invention.

[0028] Figure 8 It is a three-dimensional structural schematic diagram of the secondary evaporation recovery mechanism of the present invention.

[0029] In the figure: 1-base, 2-tank, 20-spiral heat conduction pipe, 21-liquid injection pipe, 22-air outlet pipe, 23-pipeline, 24-liquid discharge pipe, 25-circular plate, 26-connecting hole, 27-wave tube, 28-mounting plate, 29-heater, 3-rotary liquid distributor, 31-rotating seat, 32-cylinder, 33-liquid distribution plate, 34-liquid distribution hole, 35-rotating tube, 36-connecting seat, 37-sealing ring, 38-motor, 39-gear set, 4-injector 1, 41-guide ring, 42-injection pipe , 43-guide plate, 5-gas-liquid separator, 50-gas-liquid separation tank, 51-exhaust pipe, 52-wire mesh demister, 53-tee pipe one, 54-fan, 55-elbow pipe, 61-mounting frame, 62-evaporation tank, 63-gas pipe, 64-tee pipe two, 65-liquid pipe, 66-solenoid valve one, 67-solenoid valve two, 68-solenoid valve three, 69-connecting plate, 610-tube bundle, 611-liquid level sensor, 612-pH online monitor, 613-injector two, 614-discharge pipe. DETAILED DESCRIPTION

[0030] The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technical personnel in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0031] See also Figure 1-Figure 7 A dilute sulfuric acid evaporation and recovery device comprises a base 1, a tank body 2 is installed on the left side of the top of 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 left side of the tank body 2, a liquid discharge 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 with a low middle and a high outer surface, so as to centrally guide the liquid to the liquid discharge pipe 24 and reduce the residual liquid, a gas-liquid separator 5 is arranged in the middle of the top of the base 1, and the gas-liquid separator 5 comprises a gas-liquid separation tank 50 installed in the middle of the top of the base 1, and an exhaust pipe 51 is connected to the top of the gas-liquid separation tank 50, and the gas-liquid separation A wire mesh demister 52 is installed in the upper part of the tank 50, and a three-way 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 with a low center and a high 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 connecting holes 26 are spaced apart on the upper and lower circular plates 25. Square wave tubes 27 are connected between the two corresponding connecting holes 26. The wave spacing of the wave tubes 27 increases layer by layer from top to bottom. The wave spacing of the wave tubes 27 is the spacing of the wave structure (that is, the distance from wave crest to wave crest). The top surface of the plate 25 is a conical surface with a low center and a high outside, so as to guide the liquid to the wave tube 27, so that the liquid can flow into the wave tube 27 faster, reduce the residence time of the liquid on the circular plate 25, and reduce the residual liquid. A heater 29 located above the upper circular plate 25 is installed in the tank body 2, and a spiral heat conducting pipe 20 is installed in the heater 29. The liquid inlet end of the spiral heat conducting pipe 20 is connected to the liquid injection pipe 21. A mounting plate 28 located between the upper circular plate 25 and the heater 29 is connected in the tank body 2. A rotary liquid distributor 3 is provided on the mounting plate 28. The rotary liquid distributor 3 is connected to the liquid outlet end of the spiral heat conducting pipe 20. The tank body 2 is provided with An injector 4 is used for injecting high-temperature gas into between two circular plates 25. The injector 4 includes a guide ring 41 installed on the tank body 2. The guide ring 41 is connected to the tank body 2. The guide ring 41 is flush with the upper circular plate 25. A gas injection pipe 42 is connected to the side of the guide ring 41. The inner top surface of the guide ring 41 is designed as an inclined surface to guide the high-temperature gas downward. Guide plates 43 for guiding the high-temperature gas are connected to the guide ring 41 at circumferential intervals so that the airflow enters the tank body 2 evenly along the guide ring 41, so that the high-temperature gas can flow evenly from top to bottom, thereby improving the heating efficiency and heating uniformity of the wave tube 27.

[0032] See also Figure 3-Figure 6 The rotary liquid distributor 3 includes a rotating seat 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 rotating seat 31, an annular slide groove for guiding the rotation of the cylinder 32 is opened on the upper circular plate 25, a liquid distribution pan 33 is connected inside the cylinder 32, liquid distribution holes 34 are spaced apart on the liquid distribution pan 33, the aperture of the liquid distribution hole 34 gradually increases from the center to the edge of the liquid distribution pan 33 (the aperture of the liquid distribution hole 34 close to the axis of the liquid distribution pan 33 is smaller than the aperture of the liquid distribution hole 34 away from the axis of the liquid distribution pan 33), the liquid distribution pan 33 is a conical disk with a high middle and a low outside, and the top of the cylinder 32 is a conical surface with a high middle and a low outside to guide the liquid from the center to the edge to ensure uniform distribution, a rotating tube 35 extending into the cylinder 32 is connected to the lower inner part of the rotating seat 31, and the upper inner part of the rotating seat 31 rotates The heater 29 is connected with a connecting seat 36, which is fixedly connected to the bottom of the heater 29. The liquid outlet end of the spiral heat-conducting pipe 20 extends into the connecting seat 36. A sealing ring 37 is connected to the connecting seat 36. The sealing ring 37 is slidably sleeved on the outside of the rotating tube 35 and the spiral heat-conducting pipe 20. The rotating tube 35 is connected to the liquid outlet end of the spiral heat-conducting pipe 20 through the sealing ring 37 to prevent liquid leakage. A driving member for driving the rotating seat 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 rotating seat 31. The output shaft of the motor 38 is connected to the rotating seat 31 through a gear set 39. The gear set 39 consists of two gears, and the two gears are respectively connected to the outer wall of the rotating seat 31 and the output shaft of the motor 38, and the two gears are meshed.

[0033] First, the heater 29 is controlled to work to heat the spiral heat-conducting tube 20, and then the dilute sulfuric acid solution is injected into the spiral heat-conducting tube 20 through the injection tube 21. The dilute sulfuric acid solution is heated by the spiral heat-conducting tube 20 to achieve preheating of 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 that the dilute sulfuric acid solution is fully preheated, and provide a preheating effect. The preheated dilute sulfuric acid solution is discharged into the cylinder 32 through the rotating tube 35, and discharged onto the liquid distribution plate 33, and then discharged to the upper circular plate 25 through the liquid distribution holes 34 on the liquid distribution plate 33, and then enters the wave tube 27. The dilute sulfuric acid solution is distributed through the wave tube 27 and forms a liquid film to flow downward.

[0034] The control motor 38 works, and drives the rotating seat 31 to rotate through the gear set 39, thereby driving the cylinder 32, the liquid distribution plate 33 and the rotating tube 35 to rotate. The liquid distribution plate 33 rotates to disperse the dilute sulfuric acid solution outward through centrifugal force, 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 27, improving the uniformity of liquid distribution, so as to improve the uniformity of film distribution. Since the aperture of the liquid distribution hole 34 gradually increases from the center to the edge of the liquid distribution plate 33 (the aperture of the liquid distribution hole 34 close to the axis of the liquid distribution plate 33 is smaller than the aperture of the liquid distribution hole 34 far from the axis of the liquid distribution plate 33), the dilute sulfuric acid solution can be distributed more evenly, further improving the uniformity of liquid distribution, so as to further improve the uniformity of film distribution, and the evaporation recovery efficiency of dilute sulfuric acid can be improved by improving the uniformity of liquid film distribution.

[0035] High-temperature gas is injected between the two circular plates 25 through the injector 4, and the high-temperature gas flows downward to heat the wave tube 27, and then the high-temperature gas is discharged from the outlet pipe 22. The dilute sulfuric acid solution is heated by the wave tube 27, so that the water in the dilute sulfuric acid solution evaporates to obtain a concentrated solution, thereby realizing the evaporation recovery of the dilute sulfuric acid. The concentrated solution is discharged downward from the wave tube 27 to the bottom of the tank body 2, and finally discharged outward through the drain pipe 24. The wave tube 27 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 27 makes the dilute sulfuric acid solution frequently hit the tube wall when flowing downward, increasing the contact area between the dilute sulfuric acid solution and the tube 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. Since the wave-shaped spacing of the wave tube 27 increases layer by layer from top to bottom, the flow rate of the dilute sulfuric acid solution can be gradually accelerated, avoiding excessive accumulation of concentrated liquid on the tube wall, which not only ensures that the dilute sulfuric acid solution is evenly heated during the entire flow process, but also effectively prevents scaling or blockage problems caused by excessive local concentration.

[0036] The hot mixed gas discharged from the wave tube 27 is discharged into the gas-liquid separation tank 50 through the pipeline 23, then flows upward through the wire mesh demister 52, and is finally discharged from the exhaust pipe 51. The wire mesh demister 52 (the wire mesh demister 52 is a prior art and will not be described here) separates the droplets entrained in the gas to prevent the liquid from being discharged with the gas. Specifically, when the gas containing tiny droplets passes through the wire mesh, these droplets will be captured by the wire mesh and aggregated into larger droplets, and finally fall to the bottom of the gas-liquid separation tank 50 due to gravity, and then are discharged outwardly through the three-way pipe 53 to achieve gas-liquid separation.

[0037] See also Figure 7-Figure 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.

[0038] 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.

[0039] When the pH online 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 online 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 electromagnetic valve 3 68 to open, and the concentrated liquid in the tube bundle 610 is input into the discharge pipe 24 through the liquid infusion pipe 65 for discharge. The controller then controls the electromagnetic valve 3 68 to close, and controls the electromagnetic valve 2 67 to open, and discharges the liquid in the gas-liquid separation tank 50 with a pH value less than the preset value (liquid that does not meet the requirements) into the evaporation tank 62. The liquid with a pH value less than the preset value (liquid that does not meet the requirements) then enters the tube bundle 610, and the high-temperature gas is injected between the two connecting plates 69 through the injector 2 613. The high-temperature gas flows downward to heat the tube bundle 610, and the high-temperature gas is then discharged from the discharge pipe 614. The liquid with a pH value lower than the preset value (liquid that does not meet the requirements) is evenly distributed through the tube bundle 610, and flows upward to form a thin film (liquid film), and is evaporated and recovered for the second time to obtain a 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 electromagnetic valve 2 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 a second 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.

[0040] See also Figure 7 A fan 54 is installed in the pipe 23, and a curved pipe 55 extending into the gas-liquid separation tank 50 is connected to the fan 54. The fan 54 can quickly pump the hot mixed gas below the lower circular plate 25 into the curved pipe 55, and then the hot mixed gas is discharged into the gas-liquid separation tank 50 through the curved pipe 55, so that the hot mixed gas can form a vortex in the gas-liquid separation tank 50 and move upward, thereby improving the gas-liquid separation efficiency. Specifically, the vortex helps the liquid droplets in the gas to separate from the gas, and the liquid droplets sink due to gravity, while the gas continues to move upward, ultimately achieving efficient gas-liquid separation.

[0041] The above-mentioned embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for those skilled in the art, several modifications, improvements and substitutions can be made without departing from the concept of the present invention, 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) mounted on the base (1), a liquid injection pipe (21) connected to the top of the tank body (2), an upper and lower circular plates (25) connected inside the tank body (2), an air outlet pipe (22) located above the lower circular plate (25) connected to the tank body (2), a liquid discharge pipe (24) connected to the bottom of the tank body (2), a gas-liquid separator (5) disposed on the base (1), the gas-liquid separator (5) being connected to the tank body (2) via a pipe (23), the pipe (23) being located below the lower circular plate (25), and characterized in that: The upper and lower circular plates (25) are both provided with connection holes (26) at intervals, and a wave tube (27) is connected between the two corresponding upper and lower connection holes (26). A heater (29) located above the upper circular plate (25) is installed in the tank body (2), and a spiral heat-conducting pipe (20) connected to the liquid injection pipe (21) is installed in the heater (29). A mounting plate (28) located between the upper circular plate (25) and the heater (29) is connected in the tank body (2). A rotary liquid distributor (3) connected to the spiral heat-conducting pipe (20) is provided on the mounting plate (28), and an injector (4) for injecting high-temperature gas into between the two circular plates (25) is provided on the tank body (2).

2. A dilute sulfuric acid evaporation recovery equipment according to claim 1, characterized in that: The wave-shaped spacing of the wave tube (27) increases layer by layer from top to bottom.

3. A dilute sulfuric acid evaporation recovery equipment 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. A dilute sulfuric acid evaporation recovery equipment according to claim 3, characterized in that: The gas-liquid separator (5) comprises a gas-liquid separation tank (50) mounted on a base (1); the gas-liquid separation tank (50) is connected to the tank body (2) via 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 mounted in the upper part of the gas-liquid separation tank (50); and a three-way pipe (53) is connected to the bottom of the gas-liquid separation tank (50).

5. A dilute sulfuric acid evaporation recovery equipment according to claim 4, characterized in that: A secondary evaporation recovery mechanism is provided on the base (1), the secondary evaporation recovery mechanism comprising a mounting frame (61) connected to the base (1), an evaporation tank (62) being mounted on the mounting frame (61), a gas delivery pipe (63) being connected to the top of the evaporation tank (62), the gas delivery pipe (63) being connected to the gas-liquid separation tank (50), a three-way pipe (64) being connected to the bottom of the evaporation tank (62), the three-way pipe (64) being connected to the three-way pipe (53), the three-way pipe (64) being connected to the discharge pipe (24) via a liquid delivery pipe (65), a solenoid valve (66) being mounted on the three-way pipe (53), a solenoid valve (67) being mounted on the three-way pipe (64), and a liquid delivery pipe (65) being connected to the discharge pipe (24). A solenoid valve 3 (68) is installed on one side of the evaporator (65) close to the tee pipe 2 (64), the evaporator (62) is connected with two upper and lower connecting plates (69), the evaporator (62) is connected with a discharge pipe (614) located above the lower connecting plate (69), a tube bundle (610) is connected between the two connecting plates (69), the tube bundle (610) passes through the connecting plates (69), the evaporator (62) is provided with an injector 2 (613) for injecting high-temperature gas between the two connecting plates (69), a liquid level sensor (611) is installed in the gas-liquid separation tank (50), and a pH online monitor (612) is installed in the gas-liquid separation tank (50).

6. A dilute sulfuric acid evaporation recovery equipment according to claim 5, 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).

7. A dilute sulfuric acid evaporation recovery device according to claim 6, 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).

8. The dilute sulfuric acid evaporation recovery equipment according to claim 7, 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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