A method for drying a high-moisture organic solid waste

Abstract

The present application relates to the technical field of high-moisture organic solid waste drying, and particularly relates to a drying method of high-moisture organic solid waste. The technical scheme can provide carbon source for target bacteria, support water diffusion channels between solid waste blocks formed by high-moisture organic solid waste, diffuse non-bound water surrounded by multiple solid waste blocks from the water diffusion channels, degrade organic matters in the high-moisture organic solid waste, increase porosity and specific surface area of the high-moisture organic solid waste, and keep the temperature of the sunlight shed and the temperature of the target mixture in the drying process below 50 DEG C, which can ensure good living conditions of the target bacteria and reduce the risk of dust explosion caused by the increase of dust concentration in the late drying period due to the introduction of target organic matter. The target mixture receives sunlight radiation, continuously turns over and is driven by a fan, so as to realize drying of the high-moisture organic solid waste.

Description

Technical Field

[0001] This invention relates to the field of measurement technology for high-moisture organic solid waste, and more particularly to a drying method for high-moisture organic solid waste. Background Technology

[0002] High-moisture organic solid waste includes organic solid waste with high moisture content generated during production and daily life processes, such as municipal waste, dyeing and printing waste, river waste, poultry and livestock manure, distiller's grains, oil sludge, and kitchen waste. High-moisture organic solid waste has the following characteristics: 1) It causes significant pollution, is extremely prone to decay and deterioration, and breeds mosquitoes and pathogens, posing a great threat to environmental protection and public health; 2) There is a large shortage, with annual production typically in the tens of millions or even billions of tons, while existing disposal capacity is severely insufficient, disposal technology is outdated, and landfill remains the primary method in some areas.

[0003] In related technologies, the drying process of high water content organic solid waste generally suffers from the common problems of low efficiency and high energy consumption. This is because high water content organic solid waste is prone to shrinkage and agglomeration during the drying process, which leads to the closure of its pore structure and a sharp increase in the resistance to the outward diffusion and evaporation of internal moisture (i.e., non-bound water).

[0004] Therefore, there is an urgent need for a drying method for high-moisture organic solid waste to solve the above-mentioned technical problems. Summary of the Invention

[0005] This invention provides a drying method for high-moisture organic solid waste, which can promote the diffusion of moisture in high-moisture organic solid waste to improve the drying effect.

[0006] This invention provides a method for drying high-moisture organic solid waste, comprising:

[0007] The high-moisture organic solid waste to be dried, the target organic matter, and the target bacterial strain are mixed to obtain a target mixture; wherein, the target organic matter is used to provide a carbon source for the target bacterial strain, and the target bacterial strain is used to degrade the organic matter in the high-moisture organic solid waste and increase the porosity and specific surface area of ​​the high-moisture organic solid waste;

[0008] The target mixture is laid inside a sunroom to receive solar radiation; wherein, the sunroom is equipped with multiple fans, and one end of the sunroom is provided with a gas inlet and the other end with a gas outlet;

[0009] The fan is used to drive the evaporated water from the target mixture out of the gas outlet;

[0010] The target mixture laid in the sunroom is continuously turned over during the drying process to ensure that the materials in the target mixture are in uniform contact; wherein, the target organic matter is also used to support the moisture diffusion channels between the solid waste clumps formed by the high water content organic solid waste, so that the unbound water surrounding the multiple solid waste clumps diffuses outward from the moisture diffusion channels;

[0011] The high-moisture organic solid waste is dried by subjecting the target mixture to sunlight radiation, continuously turning it over, and using the fan to achieve a moisture content of less than 40%. The temperature inside the sunroom and the temperature of the target mixture during the drying process do not exceed 50°C.

[0012] As can be seen from the above scheme, the drying method for high-moisture organic solid waste provided by the present invention not only provides a carbon source for the target bacteria by utilizing the target organic matter, but also supports the moisture diffusion channels between the solid waste clumps formed by the high-moisture organic solid waste, so that the unbound water surrounding multiple solid waste clumps diffuses outward from the moisture diffusion channels; by utilizing the target bacteria, the organic matter in the high-moisture organic solid waste can be degraded and the porosity and specific surface area of ​​the high-moisture organic solid waste can be increased, thereby improving the microstructure of the solid waste and increasing its permeability and permeability; the temperature inside the sunroom and the temperature of the target mixture during the drying process do not exceed 50°C, which can ensure good survival conditions for the target bacteria and reduce the risk of dust explosion caused by the increased dust concentration in the later stage of drying due to the introduction of the target organic matter; in this way, by allowing the target mixture to receive solar radiation, continuously turning the pile, and using the drive of a fan, the high-moisture organic solid waste is dried so that the moisture content of the high-moisture organic solid waste is less than 40%. Therefore, the above technical solution effectively solves the problem of low drying efficiency caused by shrinkage, agglomeration, and pore structure closure of high-moisture organic solid waste during the drying process. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 A schematic flowchart of a drying method for high-moisture organic solid waste provided in an embodiment of the present invention;

[0015] Figure 2 This is a schematic diagram of the structure of a drying system for high-moisture organic solid waste provided in an embodiment of the present invention;

[0016] Figure 3This is a schematic diagram illustrating the principle of solid waste agglomeration and prevention of agglomeration provided in an embodiment of the present invention.

[0017] Figure 4 This is a schematic diagram illustrating the principle of thermal conductivity calculation provided in an embodiment of the present invention.

[0018] Figure label:

[0019] 1-Sunroom; 2-Fan; 3-Gas inlet; 4-Gas outlet; 5-Target mixture; 6-Controller. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Please see Figure 1 and Figure 2 One embodiment of the present invention provides a method for drying high-moisture organic solid waste, comprising:

[0022] Step S1: Mix the high water content organic solid waste to be dried, the target organic matter, and the target bacterial strain to obtain target mixture 5; wherein, the target organic matter is used to provide carbon source for the target bacterial strain, and the target bacterial strain is used to degrade organic matter in the high water content organic solid waste and increase the porosity and specific surface area of ​​the high water content organic solid waste.

[0023] Step S2: The target mixture 5 is laid in the sunroom 1 to receive solar radiation; wherein, the sunroom 1 is equipped with multiple fans 2, one end of the sunroom 1 is equipped with a gas inlet 3, and the other end is equipped with a gas outlet 4;

[0024] Step S3: Use fan 2 to drive the evaporated water from the target mixture 5 out of gas outlet 4;

[0025] Step S4: The target mixture 5 laid in the sunroom 1 is continuously turned over during the drying process to ensure that the materials in the target mixture 5 are in uniform contact; wherein, the target organic matter is also used to support the water diffusion channels between the solid waste clumps formed by the high water content organic solid waste, so that the unbound water surrounding the multiple solid waste clumps diffuses outward from the water diffusion channels.

[0026] The high-moisture organic solid waste is dried by subjecting the target mixture 5 to sunlight radiation, continuously turning it over, and using the fan 2 to achieve a moisture content of less than 40%. The temperature inside the sunroom 1 and the temperature of the target mixture 5 during the drying process do not exceed 50°C.

[0027] In this embodiment, by utilizing the target organic matter, not only can a carbon source be provided for the target microorganism, but it can also support the moisture diffusion channels between the solid waste clumps formed by the high-moisture organic solid waste (see [reference]). Figure 3 Without the addition of target organic matter and without continuous turning, the channels collapse and shrink and clump together; with the addition of target organic matter and continuous turning, the channels do not collapse and shrink and clump together, allowing unbound water surrounding multiple solid waste clumps to diffuse outward from the moisture diffusion channels; by using the target microorganisms, organic matter in high-moisture organic solid waste can be degraded, and the porosity and specific surface area of ​​high-moisture organic solid waste can be increased, thereby improving the microstructure of solid waste and enhancing its permeability and permeability; the temperature inside the sunroom 1 and the temperature of the target mixture 5 during the drying process do not exceed 50℃, which can ensure good survival conditions for the target microorganisms and reduce the risk of dust explosion caused by the increased dust concentration in the later stage of drying due to the introduction of target organic matter; thus, by allowing the target mixture 5 to receive solar radiation, continuously turning, and using the fan 2, the high-moisture organic solid waste is dried, so that the moisture content of the high-moisture organic solid waste is less than 40%. Therefore, the above technical solution effectively solves the problem of low drying efficiency caused by shrinkage, agglomeration, and pore structure closure of high-moisture organic solid waste during the drying process.

[0028] It should be noted that the continuous turning operation in this embodiment of the invention can better ensure the homogeneity of the substances in the target mixture 5, thereby allowing the target organic matter to better support the moisture diffusion channels between the solid waste clumps formed by the high-moisture organic solid waste. Conversely, the fermentation heat production activity of the target strain in this embodiment of the invention has a negligible impact on drying compared to the continuous turning method that forms a large number of moisture diffusion channels. Moreover, the continuous turning operation can also adjust parameters such as moisture content, pH value, and C / N ratio in the target mixture 5, optimizing the growth environment of the target strain.

[0029] In some embodiments, the moisture content of the high-moisture organic solid waste is greater than 80%, but this embodiment of the present invention does not impose a specific limitation.

[0030] In some implementations, the target organic matter includes at least one of straw and leaves.

[0031] In some embodiments, the target bacterial species include at least one of photosynthetic bacteria, yeast, lactic acid bacteria, pseudomonads, Bacillus, and actinomycetes.

[0032] In some embodiments, the dry weight ratio of the target organic matter to the high-moisture organic solid waste is 8-12%, but this embodiment of the invention does not impose a specific limitation.

[0033] In some embodiments, the mass ratio of the target microbial strain to the dry basis of the high-moisture organic solid waste is 2-5%, but this embodiment of the present invention does not impose a specific limitation.

[0034] In one embodiment of the present invention, the location of the fan 2 within the sunroom 1 is determined as follows:

[0035] In Fluent software, the sunroom 1 is divided into grids;

[0036] Select the target mathematical model in Fluent software; the target mathematical model includes the flow model, component model and heat transfer model.

[0037] Boundary conditions were determined and assigned values ​​in Fluent software. These boundary conditions included the density, specific heat, thermal conductivity, viscosity, and laying thickness of the high-moisture organic solid waste, as well as the solar radiation intensity, wind speed, temperature, and humidity inside the sunroom 1.

[0038] Numerical simulation was performed on the drying process of high-moisture organic solid waste to obtain the flow field, humidity field, and temperature field inside the sunroom 1;

[0039] Based on the flow field, humidity field and temperature field inside the sunroom 1, the first installation position of the fan 2 inside the sunroom 1 is determined.

[0040] In this embodiment, the temperature, humidity, and flow fields are optimized by adjusting the initial position of the fan 2 within the sunroom 1. This enhances the moisture transfer process and improves the drying efficiency of high-moisture organic solid waste. Simultaneously, by modeling the physicochemical changes, heat transfer, and moisture migration of the high-moisture organic solid waste (i.e., flow model, component model, and heat transfer model), a better understanding of the physical mechanisms involved in the drying process can be achieved, thereby optimizing the design of the sunroom 1 and improving drying efficiency.

[0041] Understandably, based on the flow field within the sunroom 1, it's possible to identify stagnant areas. A fan 2 can then be placed in these stagnant areas to drive airflow. Similarly, based on the humidity field within the sunroom 1, it's possible to identify dry, dead zones. A fan 2 can then be placed in these dry, dead zones to direct airflow towards them. Furthermore, based on the temperature field within the sunroom 1, it's possible to identify the temperature distribution. A fan 2 can then be placed in areas with higher temperatures to direct airflow towards areas with lower temperatures. This setup optimizes the placement of the fan 2 within the sunroom 1.

[0042] like Figure 4 As shown, in one embodiment of the present invention, the thermal conductivity of high-moisture organic solid waste is determined as follows:

[0043] The cylindrical tube is divided into upper and lower spaces. The lower space of the cylindrical tube is filled with high-moisture organic solid waste, while the upper space of the cylindrical tube is an air space.

[0044] A heating rod is inserted at the center of the cylindrical tube to heat the high-moisture organic solid waste and air; the heating rod passes through the upper and lower spaces.

[0045] A first temperature sensor is inserted into the off-center part of the lower space, a second temperature sensor is inserted into the off-center part of the upper space, and a third temperature sensor is inserted into the center of the high-moisture organic solid waste to monitor the temperature of the heating rod; wherein, the distance from the first temperature sensor to the heating rod and the distance from the second temperature sensor to the heating rod are equal.

[0046] The thermal conductivity of high-moisture-content organic solid waste is determined using the following formula:

[0047]

[0048] In the formula, λs is the thermal conductivity, ha is the height of the upper space, hs is the height of the lower space, t1 is the temperature detected by the first temperature sensor, t2 is the temperature detected by the second temperature sensor, and t3 is the temperature detected by the third temperature sensor.

[0049] It should be noted that the above formula assumes that heat is conducted only from the cylindrical curved surface and the temperature only changes with the radius r. It is a one-dimensional steady temperature field heat conduction. According to the Fourier law of steady thermal conduction, the heat conduction rate (the amount of heat conducted per unit time) of a certain micro-element is proportional to the normal temperature gradient of the isothermal surface of the micro-element and the heat conduction area of ​​the micro-element.

[0050] In one embodiment of the present invention, a plurality of dryers (not shown in the figure) are also provided in the sunroom 1, which are used to dry organic solid waste with high water content;

[0051] The high-moisture organic solid waste is dried by subjecting the target mixture 5 to solar radiation, continuously turning it, using a fan 2 to drive it, and using a dryer to dry it.

[0052] In this embodiment, by setting up multiple dryers inside the sunroom 1, the drying efficiency of high-moisture organic solid waste can be further improved.

[0053] In one embodiment of the present invention, the second setting position of the dryer inside the sunroom 1 is determined based on the humidity field and temperature field inside the sunroom 1.

[0054] In this embodiment, the temperature and humidity fields are optimized by adjusting the second placement of the dryer within the sunroom 1, thereby enhancing the drying efficiency of high-moisture organic solid waste through strengthened moisture transfer. Simultaneously, by modeling the physicochemical changes, heat transfer, and moisture migration of the high-moisture organic solid waste (i.e., component model and heat transfer model), a better understanding of the physical mechanisms involved in the drying process can be achieved, thus optimizing the design of the sunroom 1 and improving drying efficiency.

[0055] Understandably, based on the humidity field within sunroom 1, it's possible to identify areas that are dry zones. A dryer can then be placed in these dry zones to remove moisture. Similarly, based on the temperature field within sunroom 1, the temperature distribution can be observed, allowing a dryer to be placed in cooler areas to transfer heat to those areas. This arrangement optimizes the placement of the dryer within sunroom 1.

[0056] In one embodiment of the present invention, the above method further includes:

[0057] Based on the real-time parameters of the high-moisture organic solid waste and the sunroom 1 (which can be obtained through the first sensor component and the second sensor component respectively, neither of which is shown in the figure), the operating speed of the fan 2 and the turning frequency of the continuous turning (which can be achieved through a turning rake, which is not shown in the figure) are controlled (this control logic can be implemented through the controller 6); wherein, the real-time parameters of the high-moisture organic solid waste include the density, specific heat, thermal conductivity, viscosity and laying thickness of the high-moisture organic solid waste, and the real-time parameters of the sunroom 1 include the solar radiation intensity, wind speed, temperature and humidity inside the sunroom 1.

[0058] In this embodiment, since the real-time parameters of the high-moisture organic solid waste and the sunroom 1 are constantly changing during actual engineering applications, in order to maintain a stable and efficient drying efficiency, it is possible to effectively monitor and dynamically adjust the entire drying process. That is, with the help of the controller 6, the first sensor assembly and the second sensor assembly, the operating speed of the fan 2 and the turning frequency of the turner can be controlled to better achieve efficient drying.

[0059] It is understood that the first sensor assembly includes, for example, a dynamic torque sensor (for measuring viscosity), a density sensor, a heat flow sensor (for measuring specific heat), and a temperature sensor (for measuring thermal conductivity, see above), while the second sensor assembly includes, for example, a temperature sensor, a humidity sensor, a wind speed sensor, and a radiation sensor.

[0060] In one embodiment of the present invention, the controller 6 specifically controls the operating speed of the fan 2 and the turning frequency of the rake in the following manner:

[0061] Construct a training sample set; wherein the training sample set includes the density, specific heat, thermal conductivity, viscosity and laying thickness of the high water content organic solid waste as input training samples, the solar radiation intensity, wind speed, temperature and humidity in the sunroom 1, and the solid waste characteristic index as output training samples, which is used to characterize the material properties of the high water content organic solid waste.

[0062] The constructed training sample set is input into the preset neural network model to train the neural network model and obtain a dynamically adjusted model.

[0063] The real-time parameters of the high-moisture organic solid waste and the sunroom 1 are input into the dynamic adjustment model to obtain the solid waste characteristic index at the current moment.

[0064] Based on the solid waste characteristic index at the current moment, control the operating speed of fan 2 and the turning frequency of the turner.

[0065] In this embodiment, end-to-end training and learning can be quickly achieved through machine learning. This does not require considering the correlation between various intermediate parameters, but only needs to update the weights of the neural network model based on a large amount of known data, thereby obtaining a more accurate output result. Therefore, this method can quickly establish the mapping relationship between the input (i.e., the parameters of high water content organic solid waste and sunroom 1) and the output (i.e., solid waste characteristic index).

[0066] In one embodiment of the present invention, when the controller 6 controls the operating speed of the fan 2 and the turning frequency of the turner based on the solid waste characteristic index at the current moment, it specifically performs the following operations:

[0067] If SI=0, then control fan 2 and the turning machine to start;

[0068] If 0 < SI ≤ 25, then control the operating speed of fan 2 to be 100% and the turning frequency of the rake to be 30 times / hour;

[0069] If 25 < SI ≤ 75, then control the operating speed of fan 2 to 80% and the turning frequency of the rake to 20 times / hour;

[0070] If 75 < SI ≤ 125, then control the operating speed of fan 2 to be 60% and the turning frequency of the rake to be 15 times / hour;

[0071] If 125 < SI ≤ 175, then control the operating speed of fan 2 to be 40% and the turning frequency of the rake to be 10 times / hour;

[0072] If 175 < SI ≤ 225, then control the operating speed of fan 2 to be 20% and the turning frequency of the rake to be 5 times / hour;

[0073] If 225 < SI, then control fan 2 and the rake turner to stop running;

[0074] SI represents the solid waste characteristic index at the current moment.

[0075] In this embodiment, a solid waste characteristic index (SI) is set as the judgment index of the controller 6. Compared with multiple input parameters (such as multiple parameters of high water content organic solid waste and sunroom 1), the former can more quickly achieve control of the operating speed of fan 2 and the turning frequency of turner.

[0076] It should be noted that, in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0077] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A method of drying a high-moisture organic solid waste, characterized by, The method comprises the following steps: mixing high-moisture organic solid waste to be dried, target organic matter, and target strains to obtain a target mixture; wherein the target organic matter is used to provide a carbon source for the target strains, and the target strains are used to degrade organic matter in the high-moisture organic solid waste and increase the porosity and specific surface area of the high-moisture organic solid waste; laying the target mixture in a sunlight shed to receive sunlight radiation; wherein the sunlight shed is provided with a plurality of fans, one end of the sunlight shed is provided with a gas inlet, and the other end is provided with a gas outlet; using the fans to drive the water vaporized from the target mixture to be discharged from the gas outlet; continuously turning over the target mixture laid in the sunlight shed during the drying process to make each material in the target mixture uniformly contact; wherein the target organic matter is also used to support the water diffusion channels between the solid waste blocks formed by the high-moisture organic solid waste, so that the non-bound water surrounded by a plurality of the solid waste blocks diffuses outward from the water diffusion channels; by making the target mixture receive sunlight radiation, continuously turning over, and using the driving of the fans, the drying of the high-moisture organic solid waste is realized, so that the moisture content of the high-moisture organic solid waste is less than 40%; wherein the temperature in the sunlight shed and the temperature of the target mixture during the drying process are both not more than 50℃; the setting position of the fan in the sunlight shed is determined by the following method: dividing the grid of the sunlight shed in the Fluent software; selecting a target mathematical model in the Fluent software; wherein the target mathematical model includes a flow model, a component model, and a heat transfer model; determining the boundary conditions in the Fluent software and assigning values to the boundary conditions; wherein the boundary conditions include the density, specific heat, thermal conductivity, viscosity, and laying thickness of the high-moisture organic solid waste, and the sunlight radiation intensity, wind speed, temperature, and humidity in the sunlight shed; numerically simulating the drying process of the high-moisture organic solid waste to obtain the flow field, humidity field, and temperature field in the sunlight shed; based on the flow field, humidity field, and temperature field in the sunlight shed, determining the first setting position of the fan in the sunlight shed.

2. The method of drying high water content organic solid waste according to claim 1, characterized in that, The moisture content of the high-moisture organic solid waste is greater than 80%.

3. The method of drying high water content organic solid waste according to claim 1, characterized in that, The target organic matter includes at least one of straw and leaves.

4. The method of drying high water content organic solid waste according to claim 1, characterized in that, The target strains include at least one of photosynthetic bacteria, yeast, lactic acid bacteria, pseudomonas, bacillus, and actinomycetes.

5. The method of drying high water content organic solid waste according to claim 1, characterized in that, The mass ratio of the target organic matter to the dry basis of the high-moisture organic solid waste is 8-12%.

6. The method of drying high water content organic solid waste according to claim 1, characterized in that, The mass ratio of the target strains to the dry basis of the high-moisture organic solid waste is 2-5%.

7. The method of drying high water content organic solid waste according to any one of claims 1-6, characterized in that, The sunlight shed is also provided with a plurality of drying machines, and the drying machines are used to dry the high-moisture organic solid waste; by making the target mixture receive sunlight radiation, continuously turning over, using the driving of the fans, and using the drying of the drying machines, the drying of the high-moisture organic solid waste is realized.

8. The method of drying high water content organic solid waste according to claim 7, characterized in that, The second setting position of the drying machine in the sunlight shed is determined based on the humidity field and temperature field in the sunlight shed.

9. The method of drying high water content organic solid waste according to any one of claims 1-6, characterized in that, The method further comprises the following steps: The running rotating speed of the fan and the turning frequency of the continuous turning are controlled based on real-time parameters of the high-moisture organic solid waste and the sunlight shed, wherein the real-time parameters of the high-moisture organic solid waste include density, specific heat, thermal conductivity, viscosity and laying thickness of the high-moisture organic solid waste, and the real-time parameters of the sunlight shed include sunlight radiation intensity, wind speed, temperature and humidity in the sunlight shed.

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