A waste hydrochloric acid roasting absorption and reuse device and method

Abstract

The present invention provides a device and method for roasting, absorbing and recycling waste hydrochloric acid, belonging to the technical field of hydrochloric acid recycling. It includes a waste acid storage tank, a concentration component element and a roasting furnace connected in sequence through pipelines. An iron oxide collection box and a first heat exchanger are respectively connected to the outlet of the roasting furnace. The roasting furnace is respectively connected to a gas tank and a combustion-supporting air storage tank through pipelines; the waste hydrochloric acid liquid is concentrated multiple times by the concentration component element, which can gradually increase the concentration of the waste hydrochloric acid, ensure that the hydrochloric acid concentrate finally entering the roasting furnace reaches the required concentration standard, helps to more precisely control the concentration process, reduce energy waste and improve the resource recovery rate; an absorbent reacts with hydrochloric acid vapor in the cooling absorption tower to generate a recyclable hydrochloric acid solution. At the same time, the unreacted absorbent is reused after temperature reduction treatment and filtration, realizing the recycling of the absorbent, reducing consumption and costs.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrochloric acid recycling, and specifically relates to a waste hydrochloric acid roasting absorption recycling device and method. Background Art

[0002] Waste hydrochloric acid refers to the hydrochloric acid waste liquid used in industrial production processes, especially in industries such as metal processing and electroplating. These waste liquids contain unreacted hydrochloric acid and other metal salts. If directly discharged into the environment, it will not only cause environmental pollution but also waste precious resources. Therefore, it is very important to treat and recycle waste hydrochloric acid.

[0003] The treatment methods of waste hydrochloric acid include high-temperature roasting method, solvent extraction method, evaporation method, and ion exchange resin method. Among them, the high-temperature roasting method can treat a large amount of waste acid and is suitable for large-scale industrial production. By high temperature, the hydrochloric acid and metal elements in the waste acid are converted into recyclable resources and less waste. The high-temperature roasting method is an effective waste acid treatment method. It can not only treat a large amount of waste acid, reduce environmental pollution, but also recycle valuable resources, with high economic and environmental benefits.

[0004] To carry out high-temperature roasting treatment on waste hydrochloric acid, a waste hydrochloric acid roasting absorption recycling device is required. When the existing waste hydrochloric acid roasting absorption recycling device is in use, the concentration process of the waste hydrochloric acid liquid may not be precise enough, making it difficult to ensure that the hydrochloric acid concentrate finally entering the roasting furnace reaches the required standard concentration. The absorbent consumption is large, the cost increases, and it is impossible to ensure the uniform distribution of the acid concentrate throughout the roasting area, which may lead to local overheating or insufficient roasting, affecting the resource recovery rate and product quality. Summary of the Invention

[0005] In view of the above problems, the present invention provides a waste hydrochloric acid roasting absorption recycling device and method.

[0006] The technical solution of the present invention is: a waste hydrochloric acid roasting absorption recycling device, including a waste acid storage tank, a concentration component, and a roasting furnace connected in sequence through pipelines. The outlet of the roasting furnace is respectively connected to an iron oxide collection box and a first heat exchanger. The roasting furnace is respectively connected to a gas tank and a combustion-supporting air storage tank through pipelines;

[0007] The concentration component includes a first concentrator, a second concentrator, and a third concentrator connected in sequence through pipelines, waste liquid concentration detectors provided on the first concentrator, the second concentrator, and the third concentrator, and the first concentrator, the second concentrator, and the third concentrator are respectively connected to the roasting furnace;

[0008] The first concentrator is connected to the first heat exchanger. A cooling absorption tower is connected to the outlet of the first concentrator, and a dust collector is provided at the connection. A flue gas concentration detector is provided on the cooling absorption tower. A scrubber is connected to the outlet of the cooling absorption tower, and the liquid outlet of the cooling absorption tower is connected to an acid liquid collection tank;

[0009] A reagent circulation treatment assembly is connected to the cooling absorption tower.

[0010] Further, solenoid valves are provided between the first concentrator and the second concentrator, and between the third concentrator and the second concentrator. Solenoid valves are respectively provided at the connections of the first concentrator, the second concentrator, and the third concentrator to the roasting furnace.

[0011] Note: The solenoid valve can accurately control the opening and closing of the fluid through an electric signal, which means that the material flow between each concentrator and the roasting furnace can be adjusted according to the needs in the actual production process to achieve precise flow control.

[0012] Further, both the first heat exchanger and the second heat exchanger are connected to the roasting furnace through pipelines.

[0013] Note: The roasting furnace gas in the roasting furnace enters the first heat exchanger for heat exchange and temperature reduction, and the recovered heat is supplied for use in the roasting furnace. The roasted furnace gas after heat exchange then enters the first concentrator to directly contact and exchange heat with the waste acid to reduce the temperature and concentrate the waste acid. The remaining reagent used in the cooling absorption tower is heat-exchanged and cooled by the second heat exchanger, and the recovered heat is supplied for use in the roasting furnace again. The two heat recoveries both heat the fuel gas to save the combustion-supporting air, improve the energy utilization rate of the entire system, and reduce the demand for combustion-supporting air and fuel gas.

[0014] Further, the reagent circulation treatment assembly includes an absorbent storage tank connected to the upper end of the cooling absorption tower through a pipeline, a second heat exchanger connected to the bottom end of the cooling absorption tower through a pipeline, a filter connected to the second heat exchanger, and the filter is connected to the liquid outlet of the absorbent storage tank.

[0015] Description: After the hydrochloric acid vapor is sent out from the roasting furnace, it enters the first heat exchanger for heat exchange and cooling, and then enters the first concentrator to directly contact and exchange heat with the remaining waste acid. Next, after the hydrochloric acid vapor flows out of the first concentrator, it enters the dust collector for dust removal treatment. After the dust removal treatment, the hydrochloric acid vapor enters the cooling absorption tower. At this time, the absorbent in the absorbent storage tank is pumped into the cooling absorption tower. Through the full reaction of the absorbent and the hydrochloric acid vapor, the solution generated after the reaction is collected by the acid solution collection tank and electrolyzed into hydrochloric acid solution for reuse, while the unreacted waste gas is discharged from the cooling absorption tower and discharged after being washed by the scrubber. At the same time, the unused absorbent flowing out from the bottom end of the cooling absorption tower is pumped to the second heat exchanger through a pump, cooled by the second heat exchanger, filtered by the filter, and then re-introduced into the cooling absorption tower together with the absorbent in the absorbent storage tank for reuse.

[0016] Furthermore, a filter residue assembly is provided in the waste acid storage tank. The filter residue assembly includes a fixed mounting frame provided in the waste acid storage tank, a horizontal adjustment frame provided along the length direction at the upper end of the waste acid storage tank and having horizontal sliding grooves on the inner walls of the front and rear sides, sliding bars provided in the horizontal sliding grooves, a first electric telescopic rod for driving the sliding bars to slide, a plurality of filter mesh drums driven by a motor and arranged between two relatively distributed sliding bars from left to right, and filter meshes wound around the outer walls of the respective filter mesh drums. The mesh numbers of the respective filter meshes arranged from left to right increase in sequence, and a fixing strip is provided at the end of each filter mesh. A plug hole is provided on the side wall of the fixing strip, and a plug post matching the plug hole and driven by a second electric telescopic rod is provided on the inner wall of the bottom end of the fixed mounting frame.

[0017] Description: When the waste acid liquid is stored in the waste acid storage tank, the solid impurities therein are effectively filtered by the filter residue assembly. The specific filtering process is as follows: According to the visual observation of the content and particle size of the solid impurities in the waste acid liquid, the filter meshes of different mesh numbers are used for targeted filtering. After selecting the filter mesh to be used, through the extension and compression of each first electric telescopic rod, the corresponding sliding bar is driven to slide in the horizontal sliding groove, so that the filter mesh drum corresponding to the selected filter mesh slides left and right on the waste acid storage tank. When the fixing strip at the bottom end of the filter mesh is located at the upper opening of the fixed mounting frame, the corresponding filter mesh drum is driven to rotate by the motor, so that the filter mesh is wound down from the filter mesh drum. At the same time, the fixing strip moves down from the upper end of the fixed mounting frame to the bottom end, and the plug post is driven by the second electric telescopic rod to insert into the plug hole, so that the bottom end of the filter mesh unfolded in the fixed mounting frame is fixed. At this time, the waste acid liquid is filtered by this filter mesh. The filter mesh structure with adjustable mesh number is used to filter the solid impurities in the waste acid liquid, which improves the filtering efficiency and operation convenience, and avoids the wear or damage of the concentration group components caused by insufficient impurity filtering. At the same time, the unused filter meshes can be rolled up, which does not occupy extra space and also avoids the waste of resources. They are only unfolded and used when needed. This design not only saves materials but also is convenient for management.

[0018] Furthermore, two rows of stabilizing columns are provided on the front and back sides at both ends of the filter net, and the sum of the lengths of the two stabilizing columns on the front and back sides at the same end is less than the width of the fixed mounting frame.

[0019] Explanation: When the filter net is unfolded in the fixed mounting frame and the bottom end is fixed, in order to reduce the disturbance of the flowing waste acid liquid to the filter net, two rows of stabilizing columns are provided on the front and back sides at both ends of the filter net, which can reduce the disturbance and keep the filter net flat, improve the filtering effect, and limit the dimensional relationship between the lengths of the two stabilizing columns on the front and back sides at the same end and the width of the fixed mounting frame to ensure that the filter net can fully fall into the fixed mounting frame and ensure the normal progress of the filtering work.

[0020] Further, a liquid spraying addition tray is provided at the upper end inside the roasting furnace. The liquid spraying addition tray is respectively connected to the first concentrator, the second concentrator, and the third concentrator through connecting pipes. A through port is provided at the center of the liquid spraying addition tray, and a plurality of spraying ports are evenly provided at the bottom end of the liquid spraying addition tray. A liquid dispersing net disk is provided in each spraying port. A roasting air equalizing tray is provided inside the roasting furnace and at the lower end of the liquid dispersing net disk. The pipeline of the roasting air equalizing tray is respectively connected to the gas tank and the combustion-supporting air storage tank. Air equalizing ports are provided on the roasting air equalizing tray corresponding to the lower ends of each spraying port. A plurality of spraying holes are evenly provided along the circumferential direction on the inner wall of each air equalizing port. Burners are provided at the bottom end of the roasting air equalizing tray and corresponding to the periphery of each air equalizing port.

[0021] Explanation: After the acid concentrate concentrated by the first concentrator, the second concentrator, or the third concentrator enters the inside of the liquid spraying addition tray through the connecting pipe, it is evenly sprayed from each spraying port. At the same time, the liquid dispersing net disk at each spraying port further disperses the acid concentrate at the spraying place into smaller liquid droplets, which can increase the contact area between the acid concentrate and the gas and make it easier to fully mix with the gas, improve the thoroughness of roasting, ensure the uniform distribution of the acid concentrate in the entire roasting area, avoid local overheating or insufficiency, and contribute to achieving a more uniform roasting effect. After the gas in the gas tank and the combustion-supporting air in the combustion-supporting air storage tank enter the roasting air equalizing tray, they are evenly ejected through the spraying holes on the inner wall of each air equalizing port and are ignited by the burners to fully burn the dispersed waste hydrochloric acid liquid, generating hydrochloric acid vapor and iron oxide. The iron oxide falls to the lower part inside the roasting furnace, and the hydrochloric acid vapor is sent out from the inside of the through port and the steam outlet at the upper end of the roasting furnace. The hydrochloric acid vapor is collected by using a cooling absorption tower, and the iron oxide is collected by an iron oxide collection box. The gas is ejected through each spraying hole and directly contacts the downward acid concentrate, making the roasting treatment of the acid concentrate more thorough and also significantly improving the regeneration efficiency of the waste hydrochloric acid.

[0022] Furthermore, both the liquid spraying addition tray and the roasting air - equalizing tray are movably connected to the inner wall of the roasting furnace, and filter trays are provided at the connection points where the liquid spraying addition tray is connected to the first concentrator, the second concentrator, and the third concentrator.

[0023] Explanation: The liquid spraying addition tray and the roasting air - equalizing tray are set as detachable structures, which is convenient for replacement and cleaning, ensuring the normal operation of the roasting furnace. By setting filter trays at the connection points between the liquid spraying addition tray and the first concentrator, the second concentrator, and the third concentrator, the acid concentrated liquid entering the roasting furnace is filtered to prevent impurities from entering the roasting furnace and ensure the service life of the roasting furnace.

[0024] Further, an anti - corrosion layer is provided on the inner wall of the acid liquid collection tank, and a liquid level sensor is provided inside the acid liquid collection tank. The material of the anti - corrosion layer is epoxy resin.

[0025] Explanation: The purpose of setting the anti - corrosion layer is to prevent the acid liquid from eroding the acid liquid collection tank for a long time and affecting its service life. The liquid level sensor is used to detect the acid liquid level in the acid liquid collection tank in real time to ensure timely treatment and improve the overall automation degree of the device.

[0026] Further, an electronic flowmeter is provided at the connection point between the absorbent storage tank and the cooling absorption tower.

[0027] Explanation: The electronic flowmeter is used to detect the addition amount of the reagent entering the cooling absorption tower in real time, ensuring the treatment effect while avoiding reagent waste.

[0028] A method for roasting, absorbing, and recycling waste hydrochloric acid, based on the above - mentioned waste hydrochloric acid roasting, absorbing, and recycling device, includes the following steps:

[0029] S1. When it is necessary to treat the waste hydrochloric acid liquid, pump the waste hydrochloric acid liquid in the waste acid storage tank into the first concentrator for the first concentration treatment. After the concentration is completed, detect the concentration of the hydrochloric acid concentrated liquid through the waste liquid concentration detector at the first concentrator. When the concentration reaches the standard, open the solenoid valve to pump the hydrochloric acid concentrated liquid after the first concentration into the roasting furnace for roasting treatment. When the concentration of the hydrochloric acid concentrated liquid does not reach the standard, pump the hydrochloric acid concentrated liquid into the second concentrator for the second concentration treatment. After the concentration is completed, detect the concentration again through the corresponding waste liquid concentration detector. After reaching the standard, pump it into the roasting furnace. If it does not reach the standard, it enters the third concentrator for the third concentration treatment until the concentration reaches the standard requirements;

[0030] S2. After the hydrochloric acid concentrate reaching the standard concentration enters the roasting furnace, gas is fed into the roasting furnace through the gas tank, and combustion-supporting air is fed into the roasting furnace through the combustion-supporting air storage tank. Then, the hydrochloric acid concentrate entering the roasting furnace is fully roasted by the gas. After roasting, hydrochloric acid vapor and iron oxide are generated. The iron oxide falls to the lower part inside the roasting furnace and is collected through the iron oxide collection box. The hydrochloric acid vapor is sent out through the through-port and the vapor outlet at the upper end of the roasting furnace.

[0031] S3. After the hydrochloric acid vapor is sent out from the roasting furnace, it enters the first heat exchanger for heat exchange and temperature reduction, and then enters the first concentrator to directly contact and exchange heat with the remaining waste acid. Next, after the hydrochloric acid vapor flows out of the first concentrator, it enters the dust collector for dust removal treatment. After the dust removal treatment is completed, the hydrochloric acid vapor enters the cooling absorption tower. At this time, the absorbent is pumped into the cooling absorption tower through the reagent circulation treatment component. Through the full reaction of the absorbent with the hydrochloric acid vapor, the solution generated after the reaction is collected by the acid liquid collection box and electrolyzed into hydrochloric acid solution for reuse, while the unreacted waste gas is discharged from the cooling absorption tower and discharged after being washed by the scrubber. At the same time, the unused absorbent flowing out from the bottom end of the cooling absorption tower is pumped to the reagent circulation treatment component through a pump, and after temperature reduction and filtration treatment, it is reused.

[0032] Compared with the prior art, the beneficial effects of the present invention are:

[0033] When the waste hydrochloric acid roasting absorption and reuse device of the present invention is in use, the waste hydrochloric acid liquid is concentrated multiple times through the concentration component, which can gradually increase the concentration of the waste hydrochloric acid, ensure that the hydrochloric acid concentrate finally entering the roasting furnace reaches the required concentration standard, helps to more precisely control the concentration process, reduce energy waste, and improve the resource recovery rate. The acid concentrate is dispersed and sprayed through the liquid spraying addition plate in the roasting furnace. At the same time, the gas and combustion-supporting air are evenly ejected through the roasting air distribution plate, which can increase the contact area between the acid concentrate and the gas and make it easier to fully mix with the gas, improve the thoroughness of roasting, ensure that the acid concentrate is evenly distributed throughout the roasting area, and avoid local overheating or non-uniformity; the operations of pumping, heat exchange, and filtration of the hydrochloric acid vapor through the cooling absorption tower and the reagent circulation treatment component can be realized through the automatic control system, which improves the accuracy and efficiency of the operation, reduces the need for manual intervention. Using the absorbent to react with the hydrochloric acid vapor in the cooling absorption tower to generate recyclable hydrochloric acid solution, and at the same time, the unreacted absorbent is reused after temperature reduction treatment and filtration, realizing the recycling of the absorbent and reducing consumption and costs. Description of the Drawings

[0034] Figure 1 is the overall external structure schematic diagram of the present invention;

[0035] Figure 2 is the installation top view of the filter residue component on the waste acid storage tank of the present invention;

[0036] Figure 3 is the front elevation of the installation of the filter residue component of the present invention on the waste acid storage tank;

[0037] Figure 4 is a partial structural schematic diagram of the filter net of the present invention;

[0038] Figure 5 is a schematic diagram of the internal structure of the roasting furnace of the present invention;

[0039] Figure 6 is a schematic diagram of the structure of the liquid spraying addition tray of the present invention;

[0040] Figure 7 is a schematic diagram of the structure of the roasting air - equalizing tray of the present invention;

[0041] Among them, 1 - waste acid storage tank, 10 - filter residue component, 100 - fixed mounting rack, 101 - horizontal adjusting rack, 1010 - horizontal sliding groove, 102 - sliding bar, 103 - first electric telescopic rod, 104 - filter net reel, 105 - filter net, 106 - fixing bar, 1060 - insertion hole, 107 - second electric telescopic rod, 108 - insertion column, 109 - stabilizing column, 2 - concentration group element, 20 - solenoid valve, 21 - first concentrator, 210 - cooling absorption tower, 211 - dust collector, 212 - flue gas concentration detector, 213 - scrubber, 214 - acid liquid collection box, 215 - liquid level sensor, 22 - second concentrator, 23 - third concentrator, 24 - waste liquid concentration detector, 25 - reagent recycling and treatment component, 250 - absorbent storage box, 251 - second heat exchanger, 252 - filter, 253 - electronic flowmeter, 3 - roasting furnace, 30 - iron oxide collection box, 31 - first heat exchanger, 32 - gas tank, 33 - combustion - supporting air storage tank, 34 - liquid spraying addition tray, 340 - spraying port, 341 - liquid - spreading net disk, 342 - filter disk, 35 - roasting air - equalizing tray, 350 - air - equalizing port, 351 - injection hole, 352 - burner, 4 - through - hole. Detailed Embodiments

[0042] In order to further understand the content of the present invention, the following provides a detailed description of the present invention through embodiments.

[0043] Embodiment 1

[0044] As Figure 1As shown in the figure, a waste hydrochloric acid roasting absorption and reuse device includes a waste acid storage tank 1, a concentration unit component 2, and a roasting furnace 3 connected in sequence through pipelines. An iron oxide collection box 30 and a first heat exchanger 31 are respectively connected to the outlet of the roasting furnace 3. The roasting furnace 3 is respectively connected to a gas tank 32 and a combustion-supporting air storage tank 33 through pipelines. Among them, the first heat exchanger 31 adopts the existing technology. The gas stored in the gas tank 32 is natural gas with a purity of 99.999%;

[0045] The concentration unit component 2 includes a first concentrator 21, a second concentrator 22, and a third concentrator 23 connected in sequence through pipelines and solenoid valves 20 are respectively provided at the connection points, and waste liquid concentration detectors 24 are provided on the first concentrator 21, the second concentrator 22, and the third concentrator 23. The first concentrator 21, the second concentrator 22, and the third concentrator 23 are respectively connected to the roasting furnace 3 and solenoid valves 20 are respectively provided at the connection points. Among them, the first concentrator 21, the second concentrator 22, the third concentrator 23, and the solenoid valves 20 all adopt the existing technology;

[0046] The first concentrator 21 is connected to the first heat exchanger 31. A cooling absorption tower 210 is connected to the gas outlet of the first concentrator 21 and a dust collector 211 is provided at the connection point. A flue gas concentration detector 212 is provided on the cooling absorption tower 210. A scrubber 213 is connected to the gas outlet of the cooling absorption tower 210. The liquid outlet of the cooling absorption tower 210 is connected to an acid liquid collection box 214. Among them, the dust collector 211, the flue gas concentration detector 212, and the scrubber 213 all adopt the existing technology;

[0047] A reagent circulation treatment assembly 25 is connected to the cooling absorption tower 210. The reagent circulation treatment assembly 25 includes an absorbent storage tank 250 connected to the upper end of the cooling absorption tower 210 through a pipeline, a second heat exchanger 251 connected to the bottom end of the cooling absorption tower 210 through a pipeline, and a filter 252 connected to the second heat exchanger 251. The filter 252 is connected to the liquid outlet of the absorbent storage tank 250. Among them, the second heat exchanger 251 and the filter 252 both adopt the existing technology, and the absorbent stored in the absorbent storage tank 250 is sodium hydroxide;

[0048] Both the first heat exchanger 31 and the second heat exchanger 251 are connected to the roasting furnace 3 through pipelines. After the roasting furnace gas in the roasting furnace 3 enters the first heat exchanger 31 for heat exchange and temperature reduction, the heat is recovered and supplied for use in the roasting furnace 3. The roasted furnace gas after heat exchange then enters the first concentrator 21 to directly contact and exchange heat with the waste acid to reduce the temperature and concentrate the waste acid. The remaining reagent used in the cooling absorption tower 210 is cooled and its temperature is reduced through the second heat exchanger 251, and the heat is recovered again for use in the roasting furnace 3. The heat is recovered twice to heat the gas, so as to save the combustion-supporting air, improve the energy utilization rate of the whole system, and reduce the demand for combustion-supporting air and gas;

[0049] The inner wall of the acid liquid collection tank 214 is provided with an anti-corrosion layer. A liquid level sensor 215 is arranged in the acid liquid collection tank 214. The material of the anti-corrosion layer is epoxy resin. The purpose of setting the anti-corrosion layer is to prevent the acid liquid from eroding the acid liquid collection tank 214 for a long time and affecting its service life. The liquid level sensor 215 is used to detect the acid liquid level in the acid liquid collection tank 214 in real time to ensure timely treatment and improve the overall automation degree of the device. Among them, the liquid level sensor 215 adopts the existing technology;

[0050] An electronic flowmeter 253 is arranged at the connection between the absorbent storage tank 250 and the cooling absorption tower 210. The electronic flowmeter 253 is used to detect the addition amount of the reagent entering the cooling absorption tower 210 in real time, which can ensure the treatment effect and avoid reagent waste. Among them, the electronic flowmeter 253 adopts the existing technology.

[0051] Example 2

[0052] This example discloses a method for roasting, absorbing and recycling waste hydrochloric acid. Based on the waste hydrochloric acid roasting, absorbing and recycling device of Example 1, it includes the following steps:

[0053] S1. When it is necessary to treat the waste hydrochloric acid liquid, pump the waste hydrochloric acid liquid in the waste acid storage tank 1 into the first concentrator 21, and perform the first concentration treatment through the first concentrator 21. After the concentration is completed, detect the concentration of the hydrochloric acid concentrate through the waste liquid concentration detector 24 at the first concentrator 21. When the concentration reaches the standard, open the solenoid valve 20 to pump the hydrochloric acid concentrate after the first concentration into the roasting furnace 3 for roasting treatment. When the concentration of the hydrochloric acid concentrate does not reach the standard, pump the hydrochloric acid concentrate into the second concentrator 22 for the second concentration treatment. After the concentration is completed, detect the concentration again through the corresponding waste liquid concentration detector 24. After reaching the standard, pump it into the roasting furnace 3. If it does not reach the standard, it enters the third concentrator 23 for the third concentration treatment until the concentration reaches the standard requirements;

[0054] S2. When the hydrochloric acid concentrate with the standard concentration enters the roasting furnace 3, send gas into the roasting furnace 3 through the gas tank 32, and send combustion-supporting air into the roasting furnace 3 through the combustion-supporting air storage tank 33. Then, fully roast the hydrochloric acid concentrate entering the roasting furnace 3 with the gas. After roasting, hydrochloric acid vapor and iron oxide are generated. The iron oxide falls to the lower part inside the roasting furnace 3 and is collected through the iron oxide collection box 30. The hydrochloric acid vapor is sent out through the through-port 4 and the steam outlet at the upper end of the roasting furnace 3;

[0055] S3. After the hydrochloric acid vapor is sent out from the roasting furnace 3, it enters the first heat exchanger 31 for heat exchange and temperature reduction, and then enters the first concentrator 21 to directly contact and exchange heat with the remaining waste acid. Next, after the hydrochloric acid vapor flows out from the first concentrator 21, it enters the dust collector 211 for dust removal treatment. After the dust removal treatment is completed, the hydrochloric acid vapor enters the cooling absorption tower 210. At this time, the absorbent in the absorbent storage tank 250 is pumped into the cooling absorption tower 210. Through the full reaction of the absorbent and the hydrochloric acid vapor, the solution generated after the reaction is collected by the acid solution collection box 214 and electrolyzed into hydrochloric acid solution for reuse, while the unreacted waste gas is discharged from the cooling absorption tower 210 and discharged after being washed by the scrubber 213. At the same time, the unused absorbent flowing out from the bottom end of the cooling absorption tower 210 is pumped through a pump to the second heat exchanger 251, and after being cooled by the second heat exchanger 251 and filtered by the filter 252, it is re-introduced into the cooling absorption tower 210 together with the absorbent in the absorbent storage tank 250 for reuse.

[0056] Example 3

[0057] The difference between this example and Example 1 is as follows:

[0058] As Figure 2 、 3 shown in FIGS. 4, a filter residue assembly 10 is provided in the waste acid storage tank 1. The filter residue assembly 10 includes a fixed mounting frame 100 provided in the waste acid storage tank 1, a horizontal adjustment frame 101 provided along the length direction at the upper end of the waste acid storage tank 1 and having horizontal sliding grooves 1010 provided on the inner walls of both the front and rear sides, sliding bars 102 provided in the horizontal sliding grooves 1010, first electric telescopic rods 103 for driving the sliding bars 102 to slide, a plurality of filter mesh drums 104 provided between two relatively distributed sliding bars 102 from left to right and driven by a motor, and filter meshes 105 wound around the outer walls of the respective filter mesh drums 104. The mesh numbers of the respective filter meshes 105 arranged from left to right increase in sequence, and a fixing bar 106 is provided at the end of each filter mesh 105. A plugging hole 1060 is provided on the side wall of the fixing bar 106, and a plugging post 108 that is matched with the plugging hole 1060 and driven by a second electric telescopic rod 107 is provided on the inner wall of the bottom end of the fixed mounting frame 100. Among them, when the waste acid liquid is stored in the waste acid storage tank 1, the solid impurities therein are effectively filtered by the filter residue assembly 10. The filter mesh 105 structure with adjustable mesh number is used to filter the solid impurities in the waste acid liquid, improving the filtration efficiency and operation convenience, and avoiding the wear or damage of the components of the concentration group caused by insufficient impurity filtration. At the same time, the unused filter meshes 105 can be rolled up, which does not occupy extra space and also avoids waste of resources. They are only unfolded and used when needed. This design not only saves materials but also is convenient for management;

[0059] On the front and back sides of both ends of the filter screen 105, there are two rows of stabilizing columns 109 distributed in parallel. The sum of the lengths of the two stabilizing columns 109 on the front and back sides of the same end is less than the width of the fixed mounting frame 100. The stabilizing columns 109 can reduce disturbance and keep the filter screen 105 flat, improving the filtering effect. By defining the dimensional relationship between the lengths of the two stabilizing columns 109 on the front and back sides of the same end and the width of the fixed mounting frame 100, it is ensured that the filter screen 105 can fully fall into the fixed mounting frame 100, ensuring the normal progress of the filtering work.

[0060] Example 4

[0061] The difference between this embodiment and Embodiment 2 is as follows:

[0062] In step S1, before pumping the waste hydrochloric acid liquid in the waste acid storage tank 1 to the first concentrator 21, according to the visual observation of the content and particle size of the solid impurities in the waste acid liquid, the filter screen 105 with different mesh numbers is used for targeted filtration. After selecting the filter screen 105 to be used, through the extension and compression of each first electric telescopic rod 103, the corresponding sliding bar 102 is driven to slide in the horizontal sliding groove 1010, so that the filter drum 104 corresponding to the selected filter screen 105 slides left and right on the waste acid storage tank 1. When the fixing strip 106 at the bottom end of the filter screen 105 is located at the upper opening of the fixed mounting frame 100, the corresponding filter drum 104 is driven to rotate by the motor, so that the filter screen 105 is wound down from the filter drum 104. At the same time, the fixing strip 106 moves down from the upper end of the fixed mounting frame 100 to the bottom end, and the insertion column 108 is driven by the second electric telescopic rod 107 to insert into the insertion hole 1060, so that the bottom end of the filter screen 105 unfolded in the fixed mounting frame 100 is fixed. At this time, the waste acid liquid is filtered through the filter screen 105, and the filter screen 105 structure with adjustable mesh number is used to filter the solid impurities in the waste acid liquid; after the filter screen 105 is unfolded in the fixed mounting frame 100 and the bottom end is fixed, in order to reduce the disturbance of the flow of the waste acid liquid to the filter screen 105, two rows of stabilizing columns 109 are arranged in parallel on the front and back sides of both ends of the filter screen 105, which can reduce disturbance and keep the filter screen 105 flat.

[0063] Example 5

[0064] The difference between this embodiment and Embodiment 3 is as follows:

[0065] Such as Figure 5 、 6, as shown in FIGS. 7, at the upper end inside the roasting furnace 3, there is a liquid spraying addition tray 34. The liquid spraying addition tray 34 is respectively connected to the first concentrator 21, the second concentrator 22, and the third concentrator 23 through connecting pipes. At the center of the liquid spraying addition tray 34, there is a through port 4. At the bottom end of the liquid spraying addition tray 34, 4 spraying ports 340 are evenly provided. Inside each spraying port 340, there is a liquid dispersing net disk 341. Inside the roasting furnace 3 and at the lower end of the liquid dispersing net disk 341, there is a roasting air - equalizing tray 35. The pipelines of the roasting air - equalizing tray 35 are respectively connected to the gas tank 32 and the combustion - supporting air storage tank 33. Corresponding to the lower end of each spraying port 340 on the roasting air - equalizing tray 35, there is an air - equalizing port 350. Along the circumferential direction on the inner wall of each air - equalizing port 350, 6 spraying holes 351 are evenly provided. At the bottom end of the roasting air - equalizing tray 35 and corresponding to the periphery of each air - equalizing port 350, there is a burner 352. Through the liquid dispersing net disk 341 at each spraying port 340, the acid concentrated liquid at the spraying place is further dispersed into smaller liquid droplets, which can increase the contact area between the acid concentrated liquid and the gas, making it easier to fully mix with the gas, improving the thoroughness of roasting, ensuring that the acid concentrated liquid is evenly distributed throughout the roasting area, avoiding local overheating or insufficiency, and helping to achieve a more uniform roasting effect. By ejecting the gas through each spraying hole 351 and directly contacting the downward acid concentrated liquid, the roasting treatment of the acid concentrated liquid is more sufficient and thorough, and can also significantly improve the regeneration efficiency of waste hydrochloric acid;

[0066] Both the liquid spraying addition tray 34 and the roasting air - equalizing tray 35 are movably connected to the inner wall of the roasting furnace 3. And at the connection parts where the liquid spraying addition tray 34 is connected to the first concentrator 21, the second concentrator 22, and the third concentrator 23, there are filter disks 342. Setting the liquid spraying addition tray 34 and the roasting air - equalizing tray 35 as detachable structures facilitates their replacement and cleaning, ensuring the normal operation of the roasting furnace 3. By setting filter disks 342 at the connection parts between the liquid spraying addition tray 34 and the first concentrator 21, the second concentrator 22, and the third concentrator 23, the acid concentrated liquid entering the roasting furnace 3 is filtered to prevent impurities from entering the roasting furnace 3 and ensure the service life of the roasting furnace 3.

[0067] Example 6

[0068] The difference between this example and Example 4 is that:

[0069] In step S2, when the hydrochloric acid concentrate reaching the standard concentration enters the roasting furnace 3, it first enters the internal part of the liquid spraying addition tray 34 and is evenly sprayed from each spraying port 340. At the same time, the acid concentrate at the spraying position is further dispersed into smaller droplets by the liquid dispersing net disk 341 at each spraying port 340. After the fuel gas in the fuel gas tank 32 and the combustion-supporting air in the combustion-supporting air storage tank 33 enter the roasting air-distributing tray 35, they are evenly ejected through the ejection holes 351 on the inner walls of the respective air-distributing ports 350 and are ignited by the burner 352 to fully burn the dispersed waste hydrochloric acid liquid, generating hydrochloric acid vapor and iron oxide. The iron oxide falls to the lower part inside the roasting furnace 3, and the hydrochloric acid vapor is sent out from the inside of the through port 4 and the steam outlet at the upper end of the roasting furnace 3. The cooling absorption tower 210 is used to collect the hydrochloric acid vapor, and the iron oxide is collected through the iron oxide collection box 30.

Claims

1. A device for roasting, absorbing and recycling waste hydrochloric acid, characterized in that: The invention comprises a waste acid storage tank (1), a concentration group element (2) and a roasting furnace (3) which are connected in sequence through pipelines, wherein the outlet of the roasting furnace (3) is respectively connected to an iron oxide collection box (30) and a first heat exchanger (31), and the roasting furnace (3) is respectively connected to a gas tank (32) and a combustion-supporting air storage tank (33) through pipelines; The concentrating group element (2) comprises a first concentrator (21), a second concentrator (22) and a third concentrator (23) which are sequentially connected through pipelines, and a waste liquid concentration detector (24) provided on the first concentrator (21), the second concentrator (22) and the third concentrator (23); the first concentrator (21), the second concentrator (22) and the third concentrator (23) are respectively connected to the roasting furnace (3); The first concentrator (21) is connected to the first heat exchanger (31); the air outlet of the first concentrator (21) is connected to a cooling absorption tower (210) and a dust collector (211) is provided at the connection; the cooling absorption tower (210) is provided with a flue gas concentration detector (212); the air outlet of the cooling absorption tower (210) is connected to a scrubber (213); and the liquid outlet of the cooling absorption tower (210) is connected to an acid liquid collection box (214); The cooling absorption tower (210) is connected to a reagent circulation processing assembly (25); A solenoid valve (20) is provided between the first concentrator (21) and the second concentrator (22), and between the third concentrator (23) and the second concentrator (22), and a solenoid valve (20) is provided at the connection between the first concentrator (21), the second concentrator (22), and the third concentrator (23) and the roasting furnace (3); A liquid spray adding plate (34) is provided at the upper end of the roasting furnace (3). The liquid spray adding plate (34) is connected to the first concentrator (21), the second concentrator (22) and the third concentrator (23) through connecting pipes. A through port (4) is provided at the center of the liquid spray adding plate (34). A plurality of spray ports (340) are evenly provided at the bottom end of the liquid spray adding plate (34). A liquid dispersion net plate (341) is provided in each of the spray ports (340). The liquid dispersion net plate (341) is provided in the roasting furnace (3). A roasting gas-distributing disk (35) is provided at the lower end of the disk (341), and the pipelines of the roasting gas-distributing disk (35) are respectively connected to the gas tank (32) and the combustion-supporting air storage tank (33). A gas-distributing port (350) is provided on the roasting gas-distributing disk (35) and corresponds to the lower end of each spray port (340). A plurality of injection holes (351) are evenly provided on the inner wall of each gas-distributing port (350) along the circumferential direction. A burner (352) is provided at the bottom end of the roasting gas-distributing disk (35) and corresponds to the outer periphery of each gas-distributing port (350); The liquid spray adding plate (34) and the roasting uniform gas plate (35) are both movably connected to the inner wall of the roasting furnace (3), and the connection points where the liquid spray adding plate (34) is connected to the first concentrator (21), the second concentrator (22) and the third concentrator (23) are provided with filter plates (342).

2. A waste hydrochloric acid roasting absorption recycling device according to claim 1, characterized in that: The reagent circulation processing component (25) comprises an absorbent storage box (250) connected to the upper end of the cooling absorption tower (210) through a pipeline, a second heat exchanger (251) connected to the bottom end of the cooling absorption tower (210) through a pipeline, and a filter (252) connected to the second heat exchanger (251), and the filter (252) is connected to the liquid outlet of the absorbent storage box (250).

3. The device for roasting, absorbing and recycling waste hydrochloric acid according to claim 1, characterized in that: The waste acid storage tank (1) is provided with a filter residue assembly (10), and the filter residue assembly (10) comprises a fixed mounting frame (100) arranged in the waste acid storage tank (1), a horizontal adjustment frame (101) arranged at the upper end of the waste acid storage tank (1) along the length direction and having horizontal sliding grooves (1010) on both the front and rear inner walls, a sliding bar (102) arranged in the horizontal sliding groove (1010), a first electric telescopic rod (103) driving the sliding bar (102) to slide, and two sliding bars (102) arranged opposite to each other from left to right. A plurality of filter screen reels (104) are arranged between the filter screen reels (104) and driven by a motor, and filter screens (105) are wound on the outer walls of the filter screen reels (104), the mesh sizes of the filter screens (105) arranged from left to right are increased in sequence, and a fixing bar (106) is provided at the end of each filter screen (105), a plug-in hole (1060) is provided on the side wall of the fixing bar (106), and a plug-in column (108) matching the plug-in hole (1060) and driven by a second electric telescopic rod (107) is provided on the inner wall of the bottom end of the fixing mounting frame (100).

4. The device for roasting, absorbing and recycling waste hydrochloric acid according to claim 3, characterized in that: Two rows of parallel stabilizing columns (109) are provided on the front and rear sides of both ends of the filter screen (105), and the sum of the lengths of the two stabilizing columns (109) located on the front and rear sides of the same end is less than the width of the fixed mounting frame (100).

5. The device for roasting, absorbing and recycling waste hydrochloric acid according to claim 1, characterized in that: An anti-corrosion layer is provided on the inner wall of the acid liquid collection box (214), and a liquid level sensor (215) is provided in the acid liquid collection box (214). The material of the anti-corrosion layer is epoxy resin.

6. The device for roasting, absorbing and recycling waste hydrochloric acid according to claim 2, characterized in that: An electronic current meter (253) is provided at the connection between the absorbent storage box (250) and the cooling absorption tower (210).

7. A method for roasting and absorbing waste hydrochloric acid for reuse, based on the device for roasting and absorbing waste hydrochloric acid for reuse according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. When the waste hydrochloric acid liquid needs to be treated, the waste hydrochloric acid liquid in the waste acid storage tank (1) is pumped into the first concentrator (21), and the first concentrator (21) is used for the first concentration treatment. After the concentration is completed, the concentration of the hydrochloric acid concentrate is detected by the waste liquid concentration detector (24) at the first concentrator (21). When the concentration reaches the standard, the hydrochloric acid concentrate after the first concentration is pumped into the roasting furnace (3) for roasting treatment. When the concentration of the hydrochloric acid concentrate does not reach the standard, the hydrochloric acid concentrate is pumped into the second concentrator (22) for the second concentration treatment. After the concentration is completed, the concentration is detected again by the corresponding waste liquid concentration detector (24). If it meets the standard, it is pumped into the roasting furnace (3). If it does not meet the standard, it enters the third concentrator (23) for the third concentration treatment until it is concentrated to the standard requirement. S2. When the hydrochloric acid concentrate having reached the standard concentration enters the roasting furnace (3), fuel gas is fed into the roasting furnace (3) through the fuel gas tank (32), and combustion-supporting air is fed into the roasting furnace (3) through the combustion-supporting air storage tank (33). Then, the hydrochloric acid concentrate entering the roasting furnace (3) is fully roasted by the fuel gas. After roasting, hydrochloric acid vapor and iron oxide are generated. The iron oxide falls into the lower part of the roasting furnace (3) and is collected by the iron oxide collecting box (30). The hydrochloric acid vapor is discharged from the steam outlet at the upper end of the roasting furnace (3) through the port (4); S3, after the hydrochloric acid vapor is sent out from the roasting furnace (3), it enters the first heat exchanger (31) for heat exchange and cooling, and then enters the first concentrator (21) for direct contact heat exchange with the remaining waste acid. Then, the hydrochloric acid vapor flows out of the first concentrator (21) and enters the dust collector (211) for dust removal. After the dust removal is completed, the hydrochloric acid vapor enters the cooling absorption tower (210). At this time, the absorbent is pumped into the cooling absorption tower (210) through the reagent circulation treatment component (25). The absorbent and the hydrochloric acid vapor fully react, and the solution generated after the reaction is collected by the acid collection box (214) and electrolyzed into a hydrochloric acid solution for reuse. The unreacted waste gas is discharged from the cooling absorption tower (210) and discharged after being washed by the scrubber (213). At the same time, the unused absorbent flowing out from the bottom of the cooling absorption tower (210) is pumped to the reagent circulation treatment component (25), and is reused after being cooled and filtered.

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