Continuous pickling and purification system for ultra-pure activated carbon

Abstract

The present application relates to a kind of continuous pickling and purification treatment system of ultra-pure activated carbon, belong to activated carbon production technical field, including control module and system ontology, the system ontology includes sequentially connected head-to-tail feeding section, pickling section, water washing section and discharge section, the pickling section is connected with acid liquid tank by valve, the control module is electrically connected with valve and controls the opening and closing of valve;The control module is electrically connected with sensing module, the sensing module includes temperature sensor and conductivity sensor electrically connected with control module respectively, the conductivity sensor is used to monitor the liquid conductivity of each section of pickling section, the temperature sensor is used to monitor the temperature difference data of pickling section outlet and inlet, the control module calculates conductivity difference index according to the liquid conductivity and temperature difference data of pickling section inlet and outlet, and judges whether conductivity difference index exceeds difference index threshold value, when the judgment result is yes, reduce acid flow.

Description

Technical Field

[0001] This invention belongs to the field of activated carbon production technology, specifically relating to a continuous acid washing and purification system for ultrapure activated carbon. Background Technology

[0002] Activated carbon is a material widely used in production and daily life.

[0003] Existing activated carbon acid washing equipment involves adding acid solution and then activated carbon during the acid washing process. This traditional method is time-consuming. To address this, Chinese Patent CN113245292B discloses a streamlined activated carbon acid washing and water washing integrated machine, which includes a mixing input pipeline, an acid solution input pump, an acid solution addition device, an activated carbon addition device, a cyclone acid washer, an acid solution discharge pipeline, an acid solution discharge pump, a filter press, an acid solution collection tank, an acid solution return pipeline, an acid solution flow meter, and a controller. It also includes a draining device, an activated carbon collection tank, an activated carbon screw feeder, an activated carbon addition box, a water and carbon input pipeline, an input water pump, a first cyclone water washer, a second cyclone water washer, a third cyclone water washer, a drain pipeline, a filter, a drain pump, a washing liquid conditioning tank, a drain return pump, and a drain return pipe. This invention enables activated carbon to be cleaned under the impact and hydraulic pressure of a swirling washing liquid, which significantly shortens the cleaning time of activated carbon, thereby realizing continuous feeding of acid washing and water washing operations. It features high cleaning efficiency, high acid washing and water washing efficiency, low cleaning cost, and energy saving and environmental protection.

[0004] However, continuous pickling has inherent problems. For example, it is difficult to detect key state quantities online during the pickling process. The conductivity in the solid-liquid mixed medium is severely affected by flow rate, bubbles, and solid content, resulting in high measurement noise. If a single measurement parameter is used, the high measurement noise can easily lead to insufficient accuracy in operating condition adjustment. Therefore, a continuous pickling and purification system for ultrapure activated carbon with high accuracy in operating condition adjustment based on multi-parameter coupling adjustment is needed. Summary of the Invention

[0005] To address the aforementioned problems in the existing technology, this invention provides a continuous acid washing and purification system for ultrapure activated carbon, characterized by multi-parameter coupled adjustment and high precision in operating condition regulation.

[0006] The objective of this invention can be achieved through the following technical solutions: A continuous acid washing and purification system for ultrapure activated carbon includes a control module and a system body. The system body includes a feeding section, an acid washing section, a water washing section, and a discharging section connected in sequence. The acid washing section is connected to an acid tank via a valve. The control module is electrically connected to the valve and controls the opening and closing of the valve. The control module is electrically connected to a sensing module, which includes a temperature sensor and a conductivity sensor, both electrically connected to the control module. The conductivity sensor monitors the liquid conductivity of each section of the pickling section and uploads the data to the control module. The temperature sensor monitors the temperature difference data between the inlet and outlet of the pickling section and uploads it to the control module. The control module calculates the conductivity difference index based on the liquid conductivity and temperature difference data at the inlet and outlet of the pickling section, and determines whether the conductivity difference index exceeds the difference index threshold. If the result is yes, the acid flow rate is reduced; if the result is no, the acid flow rate is increased.

[0007] As a preferred embodiment of the present invention, the conductivity sensor uploads data to the control module, the temperature sensor monitors the temperature difference data w between the outlet and inlet of the pickling section and uploads it to the control module, and the control module adjusts the acid flow rate to A1 times the original value, where A1 = D0 / D × c, D = [(y1-y2) / y1] × [1 / (1+d × w)], c and d are pre-input correction coefficients, D0 is a pre-input difference index threshold, w ≥ 0, and y1 and y2 are the liquid conductivity at the inlet and outlet of the pickling section, respectively.

[0008] As a preferred embodiment of the present invention, the sensing module is also used to monitor the moisture content and initial ash content at the feed inlet, and upload the moisture content data and initial ash content data to the control module respectively. The control module calculates the comprehensive material coefficient based on the moisture content data and initial ash content data, and determines whether the comprehensive material coefficient exceeds the threshold. When it exceeds the threshold, the acid flow rate is adjusted upward.

[0009] As a preferred embodiment of the present invention, the sensing module uploads the moisture content data W and the initial ash content data H to the control module respectively. The control module calculates the comprehensive material coefficient Z and adjusts the acid flow rate to the original A1×A2 times, where A2=Z / Z0, Z=e×W / W0+f×H / H0, e and f are pre-input correction coefficients, H0 is a pre-input ash reference value, and W0 is a pre-input moisture content reference value.

[0010] As a preferred embodiment of the present invention, the control module is electrically connected to a stirrer. After receiving several conductivity data, the control module calculates the coefficient of variation based on the variance of the conductivity data and determines whether the coefficient of variation exceeds a threshold. When the determination result is yes, the control module instructs the stirrer to start.

[0011] As a preferred embodiment of the present invention, it further includes a control panel, which is electrically connected to the control module. The control panel is used to input the values ​​of c and d, and to display the values ​​of y1, y2, and w.

[0012] The beneficial effects of this invention are as follows: (1) By setting the control module to calculate the conductivity difference index based on the temperature difference between the outlet and inlet of the pickling section and the liquid conductivity between the inlet and outlet of the pickling section, and judging that the conductivity difference index is less than the threshold, it means that the reaction is insufficient, and the acid flow rate is increased to promote the reaction. When the conductivity difference index is greater than the threshold, it means that the acid liquid is excessive, and the acid flow rate is reduced. This realizes the working condition adjustment based on the coupling of multiple environmental parameters, and improves the accuracy of the working condition adjustment. (2) By setting the control module to calculate the comprehensive material coefficient based on the moisture content data and the initial ash content data, and judging that the comprehensive material coefficient exceeds the threshold, that is, the ash or moisture content is high, the demand for acid or the ability to dilute acid is large, and the demand for acid solution is high, the acid flow rate is corrected upward, so as to realize the working condition adjustment based on the coupling of multiple environmental parameters, and further improve the accuracy of the working condition adjustment. (3) By instructing the agitator to start when “the coefficient of variation calculated from the variance of several conductivity data exceeds the threshold, indicating uneven flow or channeling”, the overall reliability of the system is improved. Attached Figure Description

[0013] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0014] Figure 1 This is a topology diagram of the modules in this invention. Detailed Implementation

[0015] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided.

[0016] Please see Figure 1 A continuous acid washing and purification system for ultrapure activated carbon includes a control module and a system body. The system body includes a feeding section, an acid washing section, a water washing section and a discharging section connected in sequence. The acid washing section is connected to the acid tank through a valve. The control module is electrically connected to the valve and controls the opening and closing of the valve. In actual continuous pickling processes, the conductivity measurement value in the solid-liquid mixed medium is severely affected by changes in flow rate, bubbles, solid particle content, and temperature. If the acid flow rate is adjusted based solely on the absolute value of conductivity, it is easy to cause misjudgment and inaccurate operation due to measurement noise. To this end, this system adopts a multi-parameter coupling adjustment strategy. Specifically, the control module is electrically connected to a sensing module, which includes a temperature sensor and a conductivity sensor, both electrically connected to the control module. The conductivity sensor monitors the liquid conductivity of each section of the pickling section and uploads the data to the control module. The temperature sensor monitors the temperature difference data between the outlet and inlet of the pickling section and uploads it to the control module. The control module calculates the conductivity difference index based on the liquid conductivity and temperature difference data at the inlet and outlet of the pickling section and determines whether the conductivity difference index exceeds the difference index threshold. If the result is yes, the acid flow rate is reduced; if the result is no, the acid flow rate is increased. Specifically, the control module receives the liquid conductivity y1 at the inlet of the pickling section and the liquid conductivity y2 at the outlet, and simultaneously receives the temperature difference data w between the outlet and inlet of the pickling section. It then calculates the conductivity difference index D according to the formula D=[(y1-y2) / y1]×[1 / (1+d×w)], where d is a pre-input correction coefficient. The physical meaning of this formula is that, firstly, the degree of acid consumption during the reaction process is characterized by calculating the relative conductivity decrease rate (y1-y2) / y1. The larger this value is, the more complete the reaction between the acid and the impurities in the activated carbon is. At the same time, the conductivity measurement value is compensated by the temperature correction term 1 / (1+d×w). This is because the conductivity of the acid increases significantly with increasing temperature. If no correction is made, the conductivity decrease rate measured at high temperature will be artificially suppressed. When the temperature difference w between the inlet and outlet increases, the denominator of the correction term increases, causing the D value to decrease accordingly, thereby avoiding misjudgment caused by temperature differences. When the calculated D is greater than D0, it means that the conductivity at the outlet has dropped too much, indicating that the acid is in excess relative to the reaction demand. At this time, the control module instructs the valve to act to reduce the acid flow rate. When D is less than D0, it means that the conductivity at the outlet has not dropped enough, indicating that the acid has been consumed excessively and the reaction has not been fully carried out. At this time, the control module instructs the valve to act to increase the acid flow rate. The above-mentioned feedback control based on the combination of conductivity difference index and temperature difference enables the system to effectively suppress measurement noise interference in a single conductivity parameter and realize the regulation of acid flow rate; By setting the control module to calculate the conductivity difference index based on the temperature difference between the inlet and outlet of the pickling section and the liquid conductivity between the inlet and outlet of the pickling section, and determining that the conductivity difference index is less than the threshold, it indicates insufficient reaction and instructs to increase the acid flow rate to promote the reaction. When the conductivity difference index is greater than the threshold, it indicates excessive acid and reduces the acid flow rate. This realizes the operation condition adjustment based on the coupling of multiple environmental parameters, which improves the accuracy of operation condition regulation.

[0017] In actual operation, there are significant differences in the initial ash content and moisture content of different batches of activated carbon raw materials. High initial ash content means that more acid solution is needed for reaction, while high moisture content will dilute the acid solution concentration after entering the pickling section. Both of these factors will cause the aforementioned feedback adjustment to lag. That is, by the time the conductivity difference index D deviates from the threshold and the acid flow rate is increased, the underwashed material has already partially passed through the pickling section. Therefore, this system introduces a feedforward correction mechanism based on feed detection; Specifically, the sensing module is also used to monitor the moisture content and initial ash content at the feed inlet, and upload the moisture content data and initial ash content data to the control module respectively. The control module calculates the comprehensive material coefficient based on the moisture content data and initial ash content data, and determines whether the comprehensive material coefficient exceeds the threshold. When it exceeds the threshold, the acid flow rate is adjusted upward. The control module receives the moisture content data W and the initial ash content data H, and calculates the comprehensive material coefficient Z according to Z=e×W / W0+f×H / H0. The control module adjusts the acid flow rate to the original A1×A2 times, where e and f are pre-input correction coefficients, W0 is the pre-input reference value of moisture content, and H0 is the pre-input reference value of ash content. The physical meaning of this formula is that when the measured moisture content W is higher than the reference value W0, it means that the activated carbon in the feed carries more moisture. This moisture will dilute the acid solution at the inlet of the pickling section. Therefore, the acid flow rate needs to be increased proportionally to compensate for the dilution effect. When the measured initial ash content H is higher than the reference value H0, it means that the total amount of impurities that need to be reacted is greater. Similarly, the acid flow rate needs to be increased. At this time, A2 is larger. Based on the aforementioned conductivity difference index feedback adjustment, the control module further corrects the target acid flow rate upward. That is, it first actively increases the acid supply according to the feed detection results, and then makes fine adjustments according to the feedback of the subsequent conductivity difference index. By setting the control module to calculate the comprehensive material coefficient based on the moisture content data and the initial ash content data, and judging that the comprehensive material coefficient exceeds the threshold, that is, the ash or moisture content is high, the demand for acid or the ability to dilute acid is large, and the demand for acid solution is high, the acid flow rate is adjusted upward. This realizes the operation condition adjustment based on the coupling of multiple environmental parameters, which further improves the accuracy of operation condition regulation.

[0018] In a continuous acid washing system, uneven flow or channeling can easily occur between solid activated carbon particles and liquid acid during the flow process. That is, the acid flows faster in some areas and slower in others, resulting in inconsistent acid concentration and reaction time for activated carbon at different locations on the same cross section. Even if the total acid flow rate and average reaction time are properly controlled, uneven washing can still occur, with some particles being overwashed and others underwashed. Therefore, after receiving several conductivity data, the control module calculates the coefficient of variation based on the variance of the conductivity data and determines whether the coefficient of variation exceeds the threshold. If the determination result is yes, the control module instructs the stirrer to start. The coefficient of variation (CV) characterizes the dispersion of conductivity at different locations within the pickling section. When CV exceeds the preset threshold, it indicates that the conductivity at each location is significantly different, and there is a significant non-uniformity in the distribution or flow state of the acid solution, i.e., channeling or poor mixing has occurred. At this time, the control module commands the agitator to start. The agitator is installed in the middle and lower part of the pickling section and specifically includes a stirring shaft and propeller blades distributed circumferentially along the stirring shaft. The stirring shaft is driven by a variable frequency motor. After starting, it forcibly stirs the solid-liquid mixture in the pickling section, destroys the channeling channels, and promotes the re-uniform mixing of activated carbon particles and acid solution. When the coefficient of variation (CV) drops below the threshold, the control module can command the agitator to stop or reduce its speed to save energy. The control module is electrically connected to a control panel, which is used to input parameters such as correction coefficients c, d, e, f, as well as the difference index threshold D0, moisture content reference value W0, and ash content reference value H0. Operators can set these coefficients on-site according to the specific acid type and activated carbon raw material characteristics.

[0019] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A continuous acid washing and purification system for ultrapure activated carbon, characterized in that: The system includes a control module and a system body. The system body includes a feeding section, an acid washing section, a water washing section and a discharging section connected in sequence. The acid washing section is connected to the acid tank through a valve. The control module is electrically connected to the valve and controls the opening and closing of the valve. The control module is electrically connected to a sensing module, which includes a temperature sensor and a conductivity sensor, both electrically connected to the control module. The conductivity sensor monitors the liquid conductivity of each section of the pickling section and uploads the data to the control module. The temperature sensor monitors the temperature difference data between the outlet and inlet of the pickling section and uploads the data to the control module. The control module calculates a conductivity difference index based on the liquid conductivity and temperature difference data at the inlet and outlet of the pickling section, and determines whether the conductivity difference index exceeds a threshold. If the result is yes, the acid flow rate is reduced; if the result is no, the acid flow rate is increased.

2. The continuous acid washing and purification system for ultrapure activated carbon according to claim 1, characterized in that: The conductivity sensor will upload the data to the control module. The temperature sensor is used to monitor the temperature difference data w between the outlet and inlet of the pickling section and upload it to the control module. The control module will adjust the acid flow rate to A1 times the original value, where A1 = D0 / D × c, D = [(y1-y2) / y1] × [1 / (1+d × w)], c and d are pre-input correction coefficients, D0 is a pre-input difference index threshold, w ≥ 0, and y1 and y2 are the liquid conductivity at the inlet and outlet of the pickling section, respectively.

3. The continuous acid washing and purification system for ultrapure activated carbon according to claim 2, characterized in that: The sensing module is also used to monitor the moisture content and initial ash content at the feed inlet, and upload the moisture content data and initial ash content data to the control module respectively. The control module calculates the comprehensive material coefficient based on the moisture content data and initial ash content data, and determines whether the comprehensive material coefficient exceeds the threshold. When it exceeds the threshold, the acid flow rate is adjusted upward.

4. The continuous acid washing and purification system for ultrapure activated carbon according to claim 1, characterized in that: The sensing module uploads the moisture content data W and the initial ash content data H to the control module respectively. The control module calculates the comprehensive material coefficient Z and adjusts the acid flow rate to the original A1×A2 times, where A2=Z / Z0, Z=e×W / W0+f×H / H0, e and f are pre-input correction coefficients, H0 is a pre-input ash reference value, and W0 is a pre-input moisture content reference value.

5. The continuous acid washing and purification system for ultrapure activated carbon according to claim 1, characterized in that: The control module is electrically connected to a stirrer. After receiving several conductivity data, the control module calculates the coefficient of variation based on the variance of the conductivity data and determines whether the coefficient of variation exceeds a threshold. If the determination result is yes, the control module instructs the stirrer to start.

6. The continuous acid washing and purification system for ultrapure activated carbon according to claim 1, characterized in that: It also includes a control panel, which is electrically connected to the control module. The control panel is used to input the values ​​of c and d, and to display the values ​​of y1, y2, and w.

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