A multi-stage sludge drying system and drying method

Abstract

The present application relates to the field of sludge drying, and particularly relates to a multi-stage sludge drying system and a drying method, the system comprising: a data acquisition unit for acquiring sludge drying data; a parameter adjustment unit for adjusting the drying duration or the initial drying temperature according to the output stability coefficient of the target gas; a first adjustment unit for determining whether to adjust the number of set temperatures according to the effective difference value according to the sludge discharge uniformity and the sludge moisture content uniformity of the second-stage sludge; a second adjustment unit for adjusting the first-stage rotating speed or performing insulation region setting analysis according to the second-stage sludge abnormality under the condition that the number of set temperatures is adjusted out of stability; an insulation region setting unit for determining to set a single insulation region or multiple insulation regions according to the sludge particle size reference value in the insulation region setting analysis; and a multi-stage drying unit. The present application can improve the sludge drying effect.

Description

Technical Field

[0001] This invention relates to the field of sludge drying, and more particularly to a multi-stage sludge drying system and drying method. Background Technology

[0002] With the continuous expansion of wastewater treatment scale, sludge treatment and disposal has become a key bottleneck restricting the development of the urban wastewater treatment sector. Currently, sludge treatment faces many severe challenges, especially the sludge drying process, where poor drying efficiency makes it difficult to achieve the goals of sludge reduction and stabilization. Furthermore, sludge treatment consumes a high amount of energy, increasing operating costs and resource consumption. Therefore, how to improve sludge drying efficiency is a problem that urgently needs to be solved by those skilled in the art.

[0003] Chinese Patent Publication No. CN117534288A discloses a two-stage superheated steam drying system, comprising: a preheating section, a drying section, and a condensate collection device. The drying section receives preheated wet sludge processed in the preheating section, performs secondary superheated steam drying on the preheated wet sludge, and conveys the dried sludge to the preheating section. The preheating section includes a first conveyor belt for receiving wet sludge, a second conveyor belt for receiving dried sludge, and multiple condensers and a dry-cold air outlet located below the second conveyor belt. The first conveyor belt is located above the second conveyor belt, and the dry-cold air outlet is located below the multiple condensers, so that the dry-cold air sequentially exchanges heat with the condensate in the condensers and the dried sludge on the second conveyor belt. The drying section is also connected to the condensate collection device, which collects the condensate in the drying section and transmits it to each condenser. However, the above solution has the following problems: it cannot dynamically adjust the drying parameters according to the drying process, resulting in insufficient flexibility and adaptability, leading to poor sludge drying effect. Summary of the Invention

[0004] To address this issue, the present invention provides a multi-stage sludge drying system and method to overcome the problem in the prior art that the drying parameters cannot be dynamically adjusted according to the drying process, resulting in insufficient flexibility and adaptability and poor sludge drying effect.

[0005] To achieve the above objectives, the present invention provides a multi-stage sludge drying system, comprising:

[0006] The data acquisition unit is used to collect sludge drying data;

[0007] A parameter adjustment unit, which is connected to the data acquisition unit, is used to adjust the drying time or the initial drying temperature according to the production stability coefficient of the target gas.

[0008] A primary adjustment unit, which is connected to the data acquisition unit and the parameter adjustment unit respectively, is used to determine whether to adjust the set temperature based on the effective difference according to the uniformity of sludge discharge and sludge moisture content of the two-stage sludge.

[0009] A secondary adjustment unit, which is connected to the primary adjustment unit, determines whether to adjust the rotation speed of the first stage or set up a heat preservation zone based on the abnormality of the second-stage sludge under the condition of temperature quantity adjustment instability.

[0010] The insulation zone setting unit is connected to the secondary adjustment unit and is used to determine whether to set up a single insulation zone or multiple insulation zones based on the sludge particle size reference value in the insulation zone setting analysis.

[0011] The multi-stage drying unit is connected to the data acquisition unit, the parameter adjustment unit, the primary adjustment unit, the secondary adjustment unit, and the heat preservation zone setting unit, respectively. It includes a horizontal thin-layer drying module for primary drying of sludge and a linear drying module connected to the horizontal thin-layer drying module for secondary drying.

[0012] Furthermore, the method for confirming the target gas includes:

[0013] The gas production state is determined based on a certain rotation speed and a thin layer thickness reference value. The gas reliability is determined based on the gas production state, and the gas with a reliability greater than the preset reliability is recorded as the target gas.

[0014] Furthermore, the parameter adjustment unit adjusts the drying time or initial drying temperature based on the production stability coefficient of the target gas, including:

[0015] If the production stability coefficient of the target gas is greater than the preset production stability coefficient, the drying time will be adjusted.

[0016] If the production stability coefficient of the target gas is less than or equal to the preset production stability coefficient, the initial drying temperature will be adjusted.

[0017] Furthermore, when the parameter adjustment unit adjusts the drying time, it calculates the difference between the output stability coefficient and the preset output stability coefficient, and determines the drying time based on the difference in stability coefficient.

[0018] The drying time and the difference in the stability coefficient are positively correlated.

[0019] Furthermore, when the parameter adjustment unit adjusts the initial drying temperature, it determines the initial drying temperature based on the gas output value.

[0020] The initial drying temperature is positively correlated with the gas output value.

[0021] Furthermore, when the uniformity of sludge discharge in the two stages is less than the preset uniformity of sludge discharge or the uniformity of sludge moisture content is less than the preset uniformity of sludge moisture content, the primary adjustment unit increases the set temperature based on the effective difference.

[0022] The increase in the number of set temperatures is positively correlated with the effective difference.

[0023] Furthermore, the secondary adjustment unit determines whether to adjust the rotation speed of the first stage or set up a heat preservation zone based on the abnormality of the sludge in the second stage, including:

[0024] If the abnormality of the second-stage sludge is less than the preset abnormality of the second-stage sludge, then the rotation speed of the first-stage sludge will be reduced according to the abnormality of the second-stage sludge.

[0025] If the abnormality of the second-stage sludge is greater than or equal to the preset abnormality of the second-stage sludge, then perform an analysis of the insulation zone settings.

[0026] The decrease in the rotational speed of the first stage is positively correlated with the abnormality of the sludge in the second stage.

[0027] Furthermore, the insulation zone setting unit sets up multiple insulation zones when the sludge particle size reference value is greater than or equal to the preset sludge particle size reference value;

[0028] In the setting of multiple insulation zones, insulation zones are set according to the degree of anomaly and the coefficient of change of calorific value. Under preset abnormal conditions, the temperature of each insulation zone is increased and adjusted according to the coefficient of variation.

[0029] The increase in temperature corresponding to a single insulation zone is positively correlated with the coefficient of variation of that insulation zone.

[0030] Furthermore, the insulation zone setting unit sets up a single insulation zone when the sludge particle size reference value is less than the preset sludge particle size reference value;

[0031] In the single insulation zone setting, the distance of the insulation surface corresponding to the insulation zone is determined according to the coking coefficient, and the distance of the insulation surface is negatively correlated with the coking coefficient.

[0032] This invention also provides a multi-stage sludge drying method, comprising:

[0033] Collect sludge drying data;

[0034] The drying time or initial drying temperature is adjusted based on the production stability coefficient of the target gas.

[0035] Whether to adjust the set temperature quantity based on the effective difference is determined by the uniformity of sludge discharge volume and sludge moisture content in the two-stage sludge.

[0036] Under the condition of temperature quantity regulation instability, the analysis is conducted to determine whether to adjust the rotation speed of the first stage or set up the heat preservation zone based on the degree of abnormality of the second stage sludge.

[0037] In the analysis of insulation zone settings, the setting of single or multiple insulation zones is determined based on the reference value of sludge particle size.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows: In the technical solution of the present invention, the stability of gas production during the drying process can be reflected in real time through the output stability coefficient. Then, the drying time or initial temperature can be adjusted in a targeted manner according to the gas output stability coefficient, so that the drying process can closely match the actual drying needs of sludge. When the output stability coefficient is high, the drying time can be appropriately extended to ensure that the sludge loses enough moisture in a stable drying environment and achieves the expected degree of drying. When the output stability coefficient is low, the drying rate can be quickly changed by adjusting the initial temperature, so that the drying process can better adapt to the changes in the characteristics of sludge, thereby improving the consistency of the drying effect and ensuring the stability of the quality of dried sludge.

[0039] Furthermore, in this invention, the uniformity of sludge discharge and the uniformity of moisture content effectively reflect the stability and drying effect of the sludge drying process. Then, based on the uniformity of sludge discharge and the uniformity of sludge moisture content in the two stages, it is determined whether to adjust the number of set temperatures according to the effective difference. By increasing the number of set temperatures, the temperature gradient in the drying process can be controlled more precisely, ensuring that the sludge receives appropriate heat supply at different drying stages, thereby improving the uniformity of the drying effect and the quality of the dried sludge.

[0040] Furthermore, in this invention, the degree of deviation of the sludge from the normal state during the drying process is reflected by the two-stage sludge anomaly degree. When the two-stage sludge anomaly degree is less than the preset two-stage sludge anomaly degree, it indicates that the drying process is relatively stable. At this time, reducing the rotation speed by one stage can prolong the residence time of the sludge in the drying equipment, further ensuring the uniformity and stability of the drying effect. When the two-stage sludge anomaly degree is greater than or equal to the preset two-stage sludge anomaly degree, it means that the drying process may experience large fluctuations. At this time, performing heat preservation zone setting analysis can improve the temperature distribution in the drying equipment, allowing the sludge to dry under suitable temperature conditions and improving the sludge drying effect.

[0041] Furthermore, this invention uses sludge particle size reference values ​​to set up single or multiple insulation zones, which better suits practical application scenarios. Using multiple insulation zones, combined with regional anomalies and calorific value variation coefficients, provides precise insulation conditions for sludge in different areas, fully considering local differences, optimizing drying effects, achieving precise and timely temperature compensation, effectively improving drying results, and avoiding localized under-drying or over-drying. In the single insulation zone setting, the distance between the insulation surfaces is positively correlated with the coking coefficient, achieving precise energy management, ensuring a high degree of match between energy input and drying requirements, and further optimizing energy utilization efficiency. Attached Figure Description

[0042] Figure 1 This is a unit connection diagram of the multi-stage sludge drying system of the present invention;

[0043] Figure 2 This is a flowchart illustrating how the present invention adjusts the drying time or initial drying temperature based on the production stability coefficient of the target gas.

[0044] Figure 3 This is a flowchart illustrating the process of determining whether to adjust the sludge drying temperature range based on the effective difference between the sludge discharge uniformity and the sludge moisture content uniformity of the two-stage sludge.

[0045] Figure 4 This is a schematic diagram of the horizontal thin-layer drying module of the present invention;

[0046] In the diagram: 1. Drying shell; 2. Feed inlet; 3. Jacket; 4. Heat transfer oil pipe; 5. Air outlet; 6. Movable partition; 7. Hollow shaft; 8. Blade; 9. Discharge outlet.

[0047] Figure 5 This is a schematic diagram of the multi-stage sludge drying method of the present invention. Detailed Implementation

[0048] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0049] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0050] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0051] Please see Figures 1 to 3 As shown, the present invention provides a multi-stage sludge drying system, comprising:

[0052] The data acquisition unit is used to collect sludge drying data;

[0053] A parameter adjustment unit, which is connected to the data acquisition unit, is used to adjust the drying time or the initial drying temperature according to the production stability coefficient of the target gas.

[0054] A primary adjustment unit, which is connected to the data acquisition unit and the parameter adjustment unit respectively, is used to determine whether to adjust the set temperature based on the effective difference according to the uniformity of sludge discharge and sludge moisture content of the two-stage sludge.

[0055] A secondary adjustment unit, which is connected to the primary adjustment unit, determines whether to adjust the rotation speed of the first stage or set up a heat preservation zone based on the abnormality of the second-stage sludge under the condition of temperature quantity adjustment instability.

[0056] The insulation zone setting unit is connected to the secondary adjustment unit and is used to determine whether to set up a single insulation zone or multiple insulation zones based on the sludge particle size reference value in the insulation zone setting analysis.

[0057] The multi-stage drying unit is connected to the data acquisition unit, the parameter adjustment unit, the primary adjustment unit, the secondary adjustment unit, and the heat preservation zone setting unit, respectively. It includes a horizontal thin-layer drying module for primary drying of sludge and a linear drying module connected to the horizontal thin-layer drying module for secondary drying.

[0058] The application scenario of this invention is sludge drying treatment. This invention has several historical records. Each historical record records at least one sludge drying treatment process, including rotation speed, thin layer thickness reference value, reliability, output stability coefficient, and second-stage sludge anomaly degree, etc. Each historical record has a corresponding qualified mark. The qualified mark records whether the sludge drying treatment process meets the user's requirements. The qualified mark can be recorded manually. It is understood that the user can determine whether the sludge drying treatment process meets the requirements based on self-defined indicators. The self-defined indicators can be, but are not limited to, dewatering rate, which will not be elaborated here. The dewatering rate is calculated as: weight of sludge after drying treatment / weight of sludge before drying treatment.

[0059] This invention sets target coefficients and relevant thresholds. The correspondence between the target coefficients and relevant thresholds is expressed by a weighting formula: Target coefficient = Weighting coefficient × Relevant threshold. Specifically, this invention uses the value of n, drying time, initial drying temperature, increase in the number of set temperatures, decrease in the rotation speed of the first stage, increase in the temperature corresponding to the insulation zone, and distance of the insulation surface as the target coefficients. The length of the temperature interval, the difference in stability coefficients, the gas output value, the effective difference, the anomaly degree of the second-stage sludge, the coefficient of variation, and the coking coefficient are used as the relevant thresholds. It can be understood that all target coefficients have corresponding relationships. For example, the value of n is positively correlated with the length of the temperature range. This positive correlation is expressed by a weighting formula. The weighting coefficient can be determined based on the user's historical experience and the degree of influence of the temperature range length on the value of n. Furthermore, the weighting coefficient can be optimized based on historical records of multiple sludge drying processes combined with a multilayer perceptron. The optimization of the weighting coefficient using a multilayer perceptron is easily understood by those skilled in the art and will not be elaborated upon here. The principle for determining the weighting coefficients corresponding to other target coefficients and relevant thresholds is the same and will not be elaborated upon here.

[0060] The temperature quantity adjustment instability condition is set as follows: after adjusting the set temperature quantity according to the effective difference, the sludge discharge uniformity of the second stage sludge is less than the preset sludge discharge uniformity or the sludge moisture content uniformity is less than the preset sludge moisture content uniformity.

[0061] The sludge drying data includes, but is not limited to, the thickness of the sludge thin layer, the sludge discharge volume of the second-stage sludge, the volume of the target gas discharged from the outlet of the horizontal thin-layer drying module, and the sludge moisture content of the second-stage sludge. The thickness of the sludge thin layer is measured by an ultrasonic sensor, the volume of the target gas discharged from the outlet of the horizontal thin-layer drying module is measured by a gas flow sensor, and the sludge discharge volume of the second-stage sludge is measured by a weighing sensor. This is content that is easily understood by those skilled in the art and will not be elaborated further.

[0062] Specifically, the methods for identifying the target gas include:

[0063] The gas production state is determined based on a certain rotation speed and a thin layer thickness reference value. The gas reliability is determined based on the gas production state, and the gas with a reliability greater than the preset reliability is recorded as the target gas.

[0064] If a certain rotation speed is greater than or equal to a preset rotation speed and the thin layer thickness reference value is less than the preset thin layer thickness reference value, then the gas production state is a stable state. At this time, the reliability of the gas is the standard deviation of the evaluation coefficient corresponding to each time point within the preset time period.

[0065] If the rotation speed is less than the preset rotation speed or the thin layer thickness reference value is greater than or equal to the preset thin layer thickness reference value, the gas production state is unstable. In this case, the gas reliability is recorded as 0.

[0066] The gas is the gas discharged from the outlet of the horizontal thin-layer drying module after the initial moment of the preset time period;

[0067] The preset time period is a time period that the user can arbitrarily select after the multiple drying units start working according to the initial working process. The value of the preset time period can be determined by the user according to the actual application scenario. The greater the user's need to improve the reliability of the target gas, the larger the value of the preset time period. One preset time period is provided, which is 20 minutes.

[0068] Starting from the initial time of the preset time period, an interval point is set every 1 minute until the preset duration is reached. The starting point and each interval point are recorded as time points.

[0069] The initial working process includes:

[0070] First stage of drying: Wet sludge enters the horizontal thin-layer drying module through the feed inlet. A motor drives a hollow shaft to rotate at 100 rpm. The drying zone of the horizontal thin-layer drying module is cylindrical. Dividing this cylindrical drying zone into three equal parts along its length yields three sub-regions. The initial drying temperature range is [80℃, 120℃]. According to the order of distance from the feed inlet of the horizontal thin-layer drying module, the temperatures of each sub-region are 80℃, 100℃, and 120℃, respectively. The sludge is then heated through heat-conducting oil pipes... Heat-conducting oil of the corresponding temperature is injected into the jacket corresponding to the sub-region. The jacket is equipped with multiple movable partitions made of heat-resistant stainless steel. With the help of a motor-driven screw, the partitions can move flexibly in the jacket, thereby flexibly dividing the jacket space and achieving precise temperature control of different regions. The blades evenly coat the sludge on the surface of the hot wall to form a thin layer of sludge. Heat is transferred to the thin layer of sludge through heat conduction. The drying time in the horizontal thin layer drying module is 15 minutes. The gas generated by the evaporation of water in the sludge due to heat is discharged through the gas outlet. After drying, the sludge is discharged through the discharge port.

[0071] Two-stage drying: The sludge discharged through the outlet of the horizontal thin-layer drying module enters the linear drying module, where it is evenly distributed by a scraper conveyor and further dried for 1 hour. The sludge is then discharged from the outlet of the linear drying module.

[0072] One rotational speed is the same as the rotational speed of the hollow shaft in the horizontal thin-layer drying module, and the other rotational speed is 100 rpm.

[0073] The reference value for the thin layer thickness is the average thickness of the sludge thin layer corresponding to each sampling point collected at the earliest time point in the preset time period. The sampling points are several points randomly selected in the drying area of ​​the horizontal thin layer drying module. The location of each sampling point is different, and there is no restriction on the specific selection location of each sampling point. Users can choose the location themselves. The number of sampling points is 10. The thickness of the sludge thin layer corresponding to a single sampling point is measured by an ultrasonic sensor. Other contents that are easy for those skilled in the art to understand will not be elaborated in detail.

[0074] The user can determine the preset rotation speed and preset thin layer thickness reference value according to the actual application scenario. The greater the user's need to improve the reliability of the target gas, the larger the preset rotation speed and the smaller the preset thin layer thickness reference value. The system provides a preset rotation speed and preset thin layer thickness reference value, and detects the average value of the rotation speed and the average value of the thin layer thickness reference value corresponding to each historical record when the gas production state is stable and meets the user's needs. These values ​​are recorded as the preset rotation speed and preset thin layer thickness reference value, respectively.

[0075] The reliability of the gas is the average value of the evaluation coefficients corresponding to each time point within the preset time period. The evaluation coefficient corresponding to a single time point = a certain rotation speed / preset a certain rotation speed - the average value of the sludge thin layer thickness corresponding to each sampling point collected at that time point / preset thin layer thickness reference value.

[0076] The preset reliability value can be determined by the user according to the actual application scenario. The greater the user's need to improve the reliability of the gas, the greater the preset reliability value. A method for setting the preset reliability value is provided, which is to record the average reliability of the target gas corresponding to each historical record that can meet the user's needs as the preset reliability.

[0077] Specifically, the parameter adjustment unit adjusts the drying time or initial drying temperature based on the production stability coefficient of the target gas, including:

[0078] If the production stability coefficient of the target gas is greater than the preset production stability coefficient, the drying time will be adjusted.

[0079] If the production stability coefficient of the target gas is less than or equal to the preset production stability coefficient, the initial drying temperature will be adjusted.

[0080] Among them, the output stability coefficient = 1 / (standard deviation of the evaluation coefficient at each time point within the preset duration + 1).

[0081] The value of the preset output stability coefficient can be determined by the user according to the actual application scenario. The smaller the value of the preset output stability coefficient, the greater the user's need to adjust the drying time. A method for determining the value of the preset output stability coefficient is provided: detect the historical records of the adjustment of the drying time, and record the average value of the output stability coefficients corresponding to the historical records that meet the user's needs as the preset output stability coefficient.

[0082] The drying time is the length of time that the drying process is carried out in the horizontal thin-layer drying module.

[0083] The initial drying temperature is the initial temperature within the drying temperature range of the horizontal thin-layer drying module.

[0084] The horizontal thin-layer drying module corresponds to a drying temperature range, which is [initial drying temperature, drying end temperature]. The drying end temperature is 120℃. The drying temperature range is divided into n equal parts, and the temperature corresponding to each division point, as well as the initial drying temperature and the drying end temperature, are all recorded as the set temperature. The value of n is positively correlated with the length of the temperature range. The length of the temperature range = drying end temperature - drying initial temperature. The drying area of ​​the horizontal thin-layer drying module is a cylinder. This cylindrical drying area is divided into (n+1) equal parts along its length, resulting in (n+2) sub-regions. Each sub-region also has a cylindrical shape, and the area of ​​the bottom surface of all these sub-regions is equal. Each sub-region corresponds to a set temperature. The sub-region closest to the feed inlet of the horizontal thin-layer drying module has the lowest set temperature, and as the distance of the sub-region from the feed inlet increases, the set temperature of the sub-region gradually increases.

[0085] Understandably, when the output stability coefficient is greater than the preset output stability coefficient, it means that the current drying process is in a relatively stable state. In this case, the main goal of the drying system is to further consolidate and utilize this stable drying condition to remove as much moisture as possible from the sludge in order to achieve the expected drying effect. By extending the drying time, the sludge can be continuously heated in a stable drying environment, thereby improving the quality of the dried sludge and ensuring the uniformity and stability of the drying effect.

[0086] When the output stability coefficient is less than or equal to the preset output stability coefficient, the stability of the drying process is relatively poor. In this case, the drying process can be strengthened by adjusting the initial drying temperature, so that the drying process can enter the high-efficiency stage more quickly, which helps to reduce unnecessary losses caused by the instability of the drying process.

[0087] Specifically, when the parameter adjustment unit adjusts the drying time, it calculates the difference between the output stability coefficient and the preset output stability coefficient, and determines the drying time based on the difference in stability coefficient.

[0088] The drying time and the difference in the stability coefficient are positively correlated.

[0089] Specifically, the difference in stability coefficient is calculated based on the output stability coefficient and the preset output stability coefficient.

[0090] Stability coefficient difference = preset output stability coefficient - output stability coefficient.

[0091] Specifically, when the parameter adjustment unit adjusts the initial drying temperature, it determines the initial drying temperature based on the gas output value.

[0092] The initial drying temperature is positively correlated with the gas output value.

[0093] The gas output value is the volume of target gas discharged from the outlet of the horizontal thin-layer drying module per unit time, expressed in m³ / h.

[0094] It is understandable that the gas output value reflects the rate of water evaporation during the drying process. By monitoring the gas output value, the drying efficiency can be reflected in real time. When the output value deviates from the target range, the initial temperature can be adjusted appropriately to optimize the drying effect and energy consumption, ensuring that the sludge is dried efficiently at the optimal temperature, thereby improving the performance and adaptability of the drying system.

[0095] Specifically, when the uniformity of sludge discharge in the two stages is less than the preset uniformity of sludge discharge or the uniformity of sludge moisture content is less than the preset uniformity of sludge moisture content, the primary adjustment unit increases the set temperature based on the effective difference.

[0096] The increase in the number of set temperatures is positively correlated with the effective difference.

[0097] Among them, the moment when the sludge is discharged from the linear drying module after the drying time is determined based on the difference in stability coefficient and the initial drying temperature is determined based on the gas output value is recorded as the starting monitoring point. An interval monitoring point is set every 10 minutes until the number of interval monitoring points is 5. The starting monitoring point and each interval monitoring point are recorded as monitoring points. The time between two adjacent monitoring points is recorded as a monitoring period.

[0098] Sludge discharge uniformity = 1 / (standard deviation of sludge discharge for each monitoring period + 1). The sludge discharge for a single monitoring period is the total amount of sludge discharged from the outlet of the linear drying module during that monitoring period, in kg.

[0099] Sludge moisture content uniformity = 1 / (standard deviation of sludge moisture content corresponding to each monitoring period + 1), sludge moisture content corresponding to a single monitoring period = 1 - M / 500. Randomly weigh 500g of sludge discharged from the outlet of the linear drying module during the monitoring period, put the sludge into an oven, and continue heating at 105℃ until its mass no longer changes and reaches a constant weight state. Record the mass of the sludge after reaching a constant weight state, and denote it as Mg.

[0100] The user can determine the preset values ​​of sludge discharge uniformity and preset sludge moisture content uniformity according to the actual application scenario. The larger the preset values ​​of sludge discharge uniformity and preset sludge moisture content uniformity, the greater the user's need to increase the number of set temperatures based on the effective difference. The system provides a preset value of sludge discharge uniformity and preset sludge moisture content uniformity, detects the historical records of users increasing the number of set temperatures based on the effective difference, and records the average value of sludge discharge uniformity and the average value of sludge moisture content uniformity corresponding to the historical records that meet the user's needs, and respectively records them as preset sludge discharge uniformity and preset sludge moisture content uniformity.

[0101] The number of temperatures set is the total number of temperatures to be set. It can be understood that the initial number of temperatures set is n+2.

[0102] Effective difference = Second-stage sludge anomaly - Average value of second-stage sludge anomaly corresponding to historical records that can meet user needs. It should be noted that when determining the effective difference based on the second-stage sludge anomaly, the second-stage sludge anomaly needs to be determined through the uniformity of sludge discharge and the uniformity of sludge moisture content. The monitoring time period involved is the time when the sludge starts to be discharged from the linear drying module after the drying time is determined based on the stability coefficient difference and the initial drying temperature is determined based on the gas output value. This time period is recorded as the monitoring time period determined by the starting monitoring point.

[0103] It is understandable that when the number of set temperatures is the same as the number of sub-regions, the increase in the number of set temperatures is the same as the increase in the number of sub-regions.

[0104] It should be noted that if the uniformity of sludge discharge in the second stage is greater than or equal to the preset uniformity of sludge discharge and the uniformity of sludge moisture content is greater than or equal to the preset uniformity of sludge moisture content, then there is no need to adjust the set temperature based on the effective difference.

[0105] It is understandable that when the uniformity of sludge discharge in the second stage is less than the preset uniformity of sludge discharge or the uniformity of sludge moisture content is less than the preset uniformity of sludge moisture content, it indicates that there is instability in the drying process. Increasing the number of set temperatures based on the effective difference can enhance the heat transfer in the drying process and improve the sludge drying effect. Adjusting the number of set temperatures based on the effective difference can improve the stability and uniformity of the drying effect.

[0106] Specifically, the secondary adjustment unit determines whether to adjust the rotation speed of the first stage or set up a heat preservation zone based on the abnormality of the sludge in the second stage, including:

[0107] If the abnormality of the second-stage sludge is less than the preset abnormality of the second-stage sludge, then the rotation speed of the first-stage sludge will be reduced according to the abnormality of the second-stage sludge.

[0108] If the abnormality of the second-stage sludge is greater than or equal to the preset abnormality of the second-stage sludge, then perform an analysis of the insulation zone settings.

[0109] The decrease in the rotational speed of the first stage is positively correlated with the abnormality of the sludge in the second stage.

[0110] Wherein, the second-stage sludge anomaly degree = -(sludge discharge uniformity / preset sludge discharge uniformity + sludge moisture content uniformity / preset sludge moisture content uniformity); it should be noted that when determining the second-stage sludge anomaly degree through sludge discharge uniformity and sludge moisture content uniformity, the monitoring time period involved is the time when sludge discharge begins from the linear drying module after the set temperature quantity is increased and adjusted according to the effective difference, and is recorded as each first monitoring time period determined by the first starting monitoring point;

[0111] The moment when sludge starts to be discharged from the linear drying module after adjusting the number of set temperatures according to the effective difference is recorded as the first starting monitoring point. A first interval monitoring point is set every 10 minutes until the number of first interval monitoring points is 5. The first starting monitoring point and each first interval monitoring point are recorded as the first monitoring point. The time between two adjacent first monitoring points is recorded as a first monitoring period.

[0112] The user can determine the preset value of the second-stage sludge anomaly degree according to the actual application scenario. The smaller the preset value of the second-stage sludge anomaly degree, the greater the user's need for insulation zone setting analysis. A method for setting the preset value of the second-stage sludge anomaly degree is provided, which detects the historical records of insulation zone setting analysis, and records the average value of the second-stage sludge anomaly degree corresponding to the historical records that meet the user's needs as the preset second-stage sludge anomaly degree.

[0113] Understandably, when the second-stage sludge anomaly degree is less than the preset second-stage sludge anomaly degree, it indicates that the drying process is relatively stable, but there are still slight anomalies. By reducing the rotation speed of the first stage, the residence time of the sludge in the drying equipment can be increased, thereby changing the contact time and contact mode between the sludge and the drying medium, allowing the sludge to be dried more fully, which helps to further improve the uniformity and stability of the drying effect. When the second-stage sludge anomaly degree is greater than or equal to the preset second-stage sludge anomaly degree, by comprehensively evaluating factors such as the temperature distribution and thermal characteristics of the sludge in the drying equipment, a reasonable heat preservation zone can be determined. This is directly related to the heat distribution and transfer efficiency in the drying equipment, thereby improving the drying effect and ensuring the smooth progress of the drying process.

[0114] Specifically, the insulation zone setting unit sets up multiple insulation zones when the sludge particle size reference value is greater than or equal to the preset sludge particle size reference value;

[0115] In the setting of multiple insulation zones, insulation zones are set according to the degree of anomaly and the coefficient of change of calorific value. Under preset abnormal conditions, the temperature of each insulation zone is increased and adjusted according to the coefficient of variation.

[0116] The increase in temperature corresponding to a single insulation zone is positively correlated with the coefficient of variation of that insulation zone.

[0117] Among them, the sludge particle size reference value is the average value of the sub-particle size reference values ​​corresponding to each first monitoring period. The sub-particle size reference value corresponding to a single first monitoring period is the average value of the particle size of a number of sludge particles randomly selected from the sludge discharged from the outlet of the linear drying module within that first monitoring period. The number of sludge particles selected in a single first monitoring period is 50. The particle size of the sludge particles is measured by sieving, which will not be elaborated in detail.

[0118] The user can determine the preset sludge particle size reference value according to the actual application scenario. The larger the preset sludge particle size reference value, the greater the user's need for setting a single insulation area. A method for setting the preset sludge particle size reference value is provided, which detects the user's historical records of setting multiple insulation areas and records the average value of the sludge particle size reference value corresponding to the historical records that meet the user's needs as the preset sludge particle size reference value.

[0119] For a single sub-region, the regional anomaly degree corresponding to the sub-region is the regional thin layer thickness corresponding to the sub-region minus the preset regional thin layer thickness. The regional thin layer thickness corresponding to a single sub-region is the average thickness of the sludge thin layer corresponding to 3 randomly selected points in the sub-region after adjusting the number of set temperatures according to the effective difference. The preset regional thin layer thickness is the average thickness of the regional thin layer corresponding to each sub-region in the historical records that can meet the user's needs.

[0120] The coefficient of change of calorific value for a single sub-region = calorific value of the sub-region - calorific value of the sub-region preceding the sub-region. The calorific value of a single sub-region is the calorific value of the sludge in the sludge thin layer in the sub-region measured by the oxygen bomb calorimetry after adjusting the number of set temperatures according to the effective difference.

[0121] Subregions with an anomaly degree greater than the preset anomaly degree or a calorific value change coefficient greater than the preset calorific value change coefficient are defined as anomaly regions.

[0122] The user can determine the values ​​of preset area anomaly degree and preset calorific value change coefficient according to the actual application scenario. The greater the user's demand for improving the sludge treatment effect, the smaller the values ​​of preset area anomaly degree and preset calorific value change coefficient. The system provides a set of preset area anomaly degree and preset calorific value change coefficient values. The average value of the area anomaly degree and the average value of the calorific value change coefficient corresponding to each abnormal area in the historical records that can meet the user's needs are recorded as preset area anomaly degree and preset calorific value change coefficient, respectively.

[0123] For each abnormal area, the bottom surface of each abnormal area that is closer to the feed inlet of the horizontal thin-layer drying module and the bottom surface of the sub-area that is farthest from the feed inlet are recorded as the insulation surface. The area between two adjacent insulation surfaces is a insulation area. The temperature of a single insulation area is the average of the set temperatures of each sub-area in that insulation area.

[0124] The preset abnormal condition is that the abnormality of the second-stage sludge after setting the insulation zone according to the regional abnormality and the coefficient of change of calorific value is still greater than the preset abnormality of the second-stage sludge. The confirmation method of the abnormality of the second-stage sludge after setting the insulation zone according to the regional abnormality and the coefficient of change of calorific value is the same as the confirmation method when determining the abnormality of the second-stage sludge by the uniformity of sludge discharge and the uniformity of sludge moisture content. The specific details will not be elaborated.

[0125] The coefficient of variation for a single insulation zone is: = average of the regional anomalies of each sub-zone within the insulation zone / average of the regional anomalies of each sub-zone within each insulation zone in the historical records that meet user needs - the second-stage sludge anomaly after setting the insulation zone based on the regional anomaly and the calorific value change coefficient / the second-stage sludge anomaly before setting the insulation zone based on the regional anomaly and the calorific value change coefficient.

[0126] Specifically, the insulation zone setting unit sets up a single insulation zone when the sludge particle size reference value is less than the preset sludge particle size reference value;

[0127] In the single insulation zone setting, the distance of the insulation surface corresponding to the insulation zone is determined according to the coking coefficient, and the distance of the insulation surface is negatively correlated with the coking coefficient.

[0128] Wherein, the coking coefficient is the average value of the coking reference value corresponding to each first monitoring period, and the coking reference value corresponding to a single first monitoring period is the mass of coked sludge discharged from the outlet of the linear drying module during the first monitoring period / the sludge discharge volume corresponding to the first monitoring period.

[0129] The distance between the insulation surfaces is the distance between the first bottom surface of the insulation area and the feed inlet of the horizontal thin-layer drying module. The second bottom surface is the bottom surface of the sub-region furthest from the feed inlet. The first bottom surface is parallel to the second bottom surface. The area between the two bottom surfaces is the insulation area. The temperature of the insulation area is the same as the set temperature of the far-distance sub-region where the first bottom surface is located. The far-distance sub-region where the first bottom surface is located is the sub-region with the first bottom surface as its bottom surface and farthest from the feed inlet of the horizontal thin-layer drying module.

[0130] Please see Figure 4 As shown, this is a structural schematic diagram of the horizontal thin-layer drying module of the present invention. The horizontal thin-layer drying module includes:

[0131] Dry shell 1;

[0132] The feed inlet 2 is connected to the outer surface of one end of the drying shell 1 along its length, and is used to feed sludge into the interior of the drying shell 1.

[0133] Jacket 3 is arranged around the outer surface of the drying shell 1. It is provided with a heat transfer oil pipe 4 for introducing heat transfer oil, an air outlet 5 for discharging the gas generated by heating, and a movable partition 6 for dividing the space of jacket 3.

[0134] A hollow shaft 7 is disposed inside the drying shell 1. Several blades are disposed on the surface of the hollow shaft 7. The hollow shaft is used to drive the blades 8 to rotate by rotating.

[0135] The discharge port 9 is located on the outer surface of the end of the drying shell 1 away from the feed port 2 along its length, and is used to discharge the dried sludge.

[0136] Please see Figure 5 As shown, this is a schematic diagram of the multi-stage sludge drying method of the present invention. The present invention also provides a multi-stage sludge drying method, comprising:

[0137] Collect sludge drying data;

[0138] The drying time or initial drying temperature is adjusted based on the production stability coefficient of the target gas.

[0139] Whether to adjust the set temperature quantity based on the effective difference is determined by the uniformity of sludge discharge volume and sludge moisture content in the two-stage sludge.

[0140] Under the condition of temperature quantity regulation instability, the analysis is conducted to determine whether to adjust the rotation speed of the first stage or set up the heat preservation zone based on the degree of abnormality of the second stage sludge.

[0141] In the analysis of insulation zone settings, the setting of single or multiple insulation zones is determined based on the reference value of sludge particle size.

[0142] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A multi-stage sludge dewatering system, characterized by, The application relates to a multi-stage sludge drying device. The device comprises a data collection unit for collecting sludge drying data; a parameter adjustment unit connected with the data collection unit for adjusting a drying time length or a drying initial temperature according to a target gas output stability coefficient; a primary adjustment unit connected with the data collection unit and the parameter adjustment unit for determining whether to adjust a setting temperature quantity according to an effective difference value according to sludge discharge uniformity and sludge moisture content uniformity of two-stage sludge; a secondary adjustment unit connected with the primary adjustment unit for adjusting a first-stage rotating speed or performing a heat preservation region setting analysis according to two-stage sludge abnormality under a setting temperature quantity adjustment instability condition; a heat preservation region setting unit connected with the secondary adjustment unit for setting a single heat preservation region or a multiple heat preservation region according to a sludge particle size reference value in the heat preservation region setting analysis; and a multi-stage drying unit connected with the data collection unit, the parameter adjustment unit, the primary adjustment unit, the secondary adjustment unit and the heat preservation region setting unit, and comprising a horizontal thin-layer drying module for one-stage sludge drying and a linear drying module connected with the horizontal thin-layer drying module for two-stage sludge drying. The output stability coefficient=1 / (a standard deviation of evaluation coefficients corresponding to each time point in a preset time length+1). The evaluation coefficient corresponding to a single time point=first-stage rotating speed / preset first-stage rotating speed-average thickness of sludge thin layers collected at the time point / preset thin-layer thickness reference value. The sludge discharge uniformity=1 / (a standard deviation of sludge discharges corresponding to each monitoring period+1), and the sludge discharge corresponding to a single monitoring period is the total amount of sludge discharged from a discharge port of the linear drying module in the monitoring period. The sludge moisture content uniformity=1 / (a standard deviation of sludge moisture contents corresponding to each monitoring period+1), and the sludge moisture content corresponding to a single monitoring period=1-M / 500, 500g of sludge discharged from the discharge port of the linear drying module in the monitoring period is randomly taken, the sludge is placed in an oven, and the sludge is continuously heated at 105 DEG C until the mass of the sludge does not change any more, the mass of the sludge after reaching the constant weight state is recorded as Mg. The effective difference value=two-stage sludge abnormality-average two-stage sludge abnormality corresponding to historical records capable of meeting user demands. The two-stage sludge abnormality=- (sludge discharge uniformity / preset sludge discharge uniformity+sludge moisture content uniformity / preset sludge moisture content uniformity). The setting temperature quantity is the total amount of setting temperatures. The target gas is determined according to the first-stage rotating speed and the thin-layer thickness reference value, the gas output state is determined according to the gas output state, the reliability of the gas is determined according to the gas output state, and the gas with a reliability greater than a preset reliability is recorded as the target gas. The parameter adjustment unit adjusts the drying time length or the drying initial temperature according to the target gas output stability coefficient, and the adjustment comprises the following steps: if the target gas output stability coefficient is greater than a preset output stability coefficient, the drying time length is adjusted. ​ ​ 2. The multi-stage sludge dewatering system of claim 1, wherein, ​ ​ 3. The multi-stage sludge dewatering system of claim 2, wherein, ​ ​ If the output stability coefficient of the target gas is less than or equal to the preset output stability coefficient, the initial drying temperature is adjusted.

4. The multi-stage sludge dewatering system of claim 3, wherein, When the parameter adjustment unit adjusts the drying time, a stability coefficient difference value is calculated according to the output stability coefficient and the preset output stability coefficient, and the drying time is determined according to the stability coefficient difference value; The drying time and the stability coefficient difference value are in a positive correlation.

5. The multi-stage sludge dewatering system of claim 4, wherein, When the parameter adjustment unit adjusts the initial drying temperature, the initial drying temperature is determined according to the gas output value; The initial drying temperature and the gas output value are in a positive correlation.

6. The multi-stage sludge dewatering system of claim 5, wherein, When the first adjustment unit is in a state that the sludge discharge uniformity of the secondary sludge is less than the preset sludge discharge uniformity or the sludge moisture content uniformity is less than the preset sludge moisture content uniformity, the number of set temperatures is increased according to the effective difference value: The increase value of the number of set temperatures and the effective difference value are in a positive correlation.

7. The multi-stage sludge dewatering system of claim 1, wherein, The second adjustment unit determines whether to adjust the primary rotation speed or performs the analysis of the heat preservation region setting according to the secondary sludge abnormality degree, including: If the secondary sludge abnormality degree is less than the preset secondary sludge abnormality degree, the primary rotation speed is reduced according to the secondary sludge abnormality degree; If the secondary sludge abnormality degree is greater than or equal to the preset secondary sludge abnormality degree, the analysis of the heat preservation region setting is performed; The reduction value of the primary rotation speed and the secondary sludge abnormality degree are in a positive correlation.

8. The multi-stage sludge dewatering system of claim 7, wherein, The heat preservation region setting unit performs the multi-heat preservation region setting when the sludge particle size reference value is greater than or equal to the preset sludge particle size reference value; In the multi-heat preservation region setting, the heat preservation region is set according to the region abnormality degree and the heat value change coefficient, and the temperature of each heat preservation region is increased according to the variation coefficient under the preset abnormality condition; The increase value of the temperature of the single heat preservation region and the variation coefficient corresponding to the heat preservation region are in a positive correlation.

9. The multi-stage sludge dewatering system of claim 8, wherein, The heat preservation region setting unit performs the single-heat preservation region setting when the sludge particle size reference value is less than the preset sludge particle size reference value; In the single-heat preservation region setting, the heat preservation surface distance corresponding to the heat preservation region is determined according to the coking coefficient, and the heat preservation surface distance and the coking coefficient are in a negative correlation.

10. A drying method using the multi-stage sludge drying system according to any one of claims 1 to 9, characterized by, Including: Collecting sludge drying data; Adjusting the drying time or the initial drying temperature according to the output stability coefficient of the target gas; Determining whether to adjust the number of set temperatures according to the effective difference value according to the sludge discharge uniformity and the sludge moisture content uniformity of the secondary sludge; When the number of set temperatures is adjusted under the instability condition, determining whether to adjust the primary rotation speed or performing the analysis of the heat preservation region setting according to the secondary sludge abnormality degree; In the analysis of the heat preservation region setting, determining whether to perform the single-heat preservation region setting or the multi-heat preservation region setting according to the sludge particle size reference value.

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