Dry anaerobic fermentation device

Abstract

The invention relates to a dry anaerobic fermentation device, and belongs to the technical field of anaerobic fermentation. Comprising a shell, a stirring mechanism, a temperature detector, a heating mechanism, a biogas slurry flow detector and a biogas flow detector, the stirring mechanism is rotationally connected to the interior of the shell, the heating mechanism is installed at the stirring end of the stirring mechanism, the temperature detector is installed on the inner side wall of the shell and detects the temperature change in the shell, and a gas conveying opening is formed in the top face of the shell; the bottom is provided with a backflow port, the biogas slurry flow detector is installed at the backflow port, the biogas flow detector is installed at the gas transmission port, the heating mechanism adjusts the heating efficiency according to the detection result of the detector, and meanwhile the heating efficiency is secondarily adjusted according to the temperature change trend of the temperature detector within the preset time interval. The dry-type anaerobic fermentation device solves the problem that the fermentation efficiency and the gas production rate are affected due to the fact that the temperature in the device is changed when biogas slurry backflow and biogas conveying are carried out in the fermentation process of an existing dry-type anaerobic fermentation device.

Description

Technical Field

[0001] The present invention belongs to the technical field of anaerobic fermentation, and particularly relates to a dry anaerobic fermentation device. Background Art

[0002] Anaerobic fermentation is a complex biochemical process involving the synergistic action of multiple microorganisms. This process is very sensitive to environmental conditions such as temperature, pH value, and nutrient components, and changes in these factors directly affect the fermentation effect and biogas production. In order to improve the fermentation efficiency and biogas production, it is necessary to monitor the key parameters of the fermentation process in real time.

[0003] A dry anaerobic fermentation device is a device for treating organic waste, which converts waste into renewable energy such as biogas through anaerobic fermentation technology. The characteristic of the dry anaerobic fermentation device is that it adopts dry treatment technology, that is, little or no water is added during the anaerobic fermentation process, so it can treat organic waste with low humidity. Compared with traditional anaerobic fermentation devices, the dry anaerobic fermentation device has higher energy conversion efficiency and a wider application range.

[0004] At the same time, the device commonly used in dry anaerobic fermentation devices is a horizontal dry anaerobic fermentation device. The horizontal dry anaerobic fermentation device includes a housing, a stirring system, and a heating system. The stirring system is used to stir the materials to evenly mix the fresh materials and the inoculated materials, and the heating system is used to heat the materials to an appropriate temperature. During the anaerobic fermentation process, in order to ensure the fermentation efficiency and gas production rate, it is necessary to reflux the biogas slurry during the anaerobic fermentation process to maintain the stability of the microbial community structure in the fermentation tank.

[0005] Moreover, during the fermentation process, the generated biogas needs to be transported out regularly. However, during the process of biogas transportation and biogas slurry reflux, the temperature in the fermentation device will change, thus affecting the fermentation efficiency and gas production. Summary of the Invention

[0006] To solve the above problems existing in the prior art, the present invention provides a dry anaerobic fermentation device, which solves the problem that the existing dry anaerobic fermentation device will cause temperature changes in the device during the biogas slurry reflux and biogas transportation during the fermentation process, thereby affecting the fermentation efficiency and gas production.

[0007] The object of the present invention can be achieved by the following technical solutions: A dry anaerobic fermentation device, comprising a housing, a stirring mechanism, a temperature detector, a heating mechanism, a biogas slurry flow detector and a biogas flow detector. The stirring mechanism is rotatably connected to the inside of the housing. The heating mechanism is installed at the stirring end of the stirring mechanism. The temperature detector is installed on the inner side wall of the housing to detect the temperature change inside the housing. An air outlet is provided on the top surface of the housing, and a return port is provided at the bottom. The biogas slurry flow detector is installed at the return port to detect the return flow rate of the return port. The biogas flow detector is installed at the air outlet to detect the gas output volume of the air outlet. The heating mechanism adjusts the heating efficiency according to the detection results of the biogas slurry flow detector and the biogas detector, and simultaneously performs secondary adjustment of the heating efficiency according to the temperature change trend of the temperature detector within a preset time interval.

[0008] As a preferred technical solution of the present invention, the stirring mechanism includes a stirring shaft and stirring blades. The stirring shaft is rotatably connected to the inside of the housing and is horizontally placed. The stirring blades are spiral and installed on the outer side wall of the stirring shaft. Flow channels are provided inside both the stirring shaft and the stirring blades, and a heat transfer medium flows in the flow channels. The heating mechanism is embedded on the outer side wall of the stirring blades.

[0009] As a preferred technical solution of the present invention, the stirring blades are composed of an upper stirring blade and a lower stirring blade. The upper stirring blade is fitted on the top surface of the lower stirring blade to form the lower stirring blade. Grooves are correspondingly provided on the fitting surfaces of the upper stirring blade and the lower stirring blade, and the two grooves form the flow channel.

[0010] As a preferred technical solution of the present invention, the heating mechanism includes an electromagnetic heater. An electromagnetic heating layer is embedded on both the upper and lower surfaces of the stirring blades, and the electromagnetic heater is electrically connected to the electromagnetic layer.

[0011] As a preferred technical solution of the present invention, the electromagnetic heating layer is made of silicon steel material.

[0012] As a preferred technical solution of the present invention, a corrosion-resistant layer is coated on the surface of the electromagnetic heating layer.

[0013] As a preferred technical solution of the present invention, the heating mechanism further includes a temperature control system. A heating control algorithm is provided in the temperature control system. The temperature control system regulates the heating efficiency through the detection results of each detector and the heating control algorithm.

[0014] As a preferred technical solution of the present invention, the biogas slurry flow detector is an electromagnetic flowmeter.

[0015] As a preferred technical solution of the present invention, the biogas flow detector is a mass flowmeter.

[0016] The beneficial effects of the present invention are as follows: The biogas slurry flow detector is installed at the reflux port to detect the amount of refluxed biogas slurry, and the biogas flow detector installed at the gas outlet also detects the amount of biogas transported. The heating mechanism adjusts the heating efficiency according to the detection results of the biogas slurry flow detector and the biogas flow detector, so as to ensure that the temperature inside the shell does not change significantly, thus affecting the fermentation efficiency. At the same time, the temperature detector is used to detect the temperature change inside the shell, and the heating mechanism further adjusts the heating efficiency according to the detection results of the temperature detector, so as to ensure that the temperature inside the shell is not affected by the refluxed biogas slurry and the transported biogas, maintain the temperature stability inside the shell, and avoid the situation that the change in temperature causes the reduction of fermentation efficiency. It solves the problem that the existing dry anaerobic fermentation device will cause the temperature inside the device to change during the biogas slurry reflux and biogas transportation in the fermentation process, thus affecting the fermentation efficiency and gas production. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] For the convenience of those skilled in the art to understand, the present invention will be further described below with reference to the accompanying drawings.

[0018] Figure 1 is a schematic structural diagram of the present invention;

[0019] Description of the main component symbols

[0020] In the figure: 1, shell; 11, gas outlet; 12, reflux port; 2, stirring mechanism; 21, stirring shaft; 22, stirring blade; 23, flow channel; 3, temperature detector; 4, heating mechanism; 5, biogas slurry flow detector; 6, biogas flow detector. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] In order to further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following will, in conjunction with the accompanying drawings and preferred embodiments, describe in detail the specific embodiments, structures, features and their effects of the present invention.

[0022] Please refer to Figure 1, this embodiment provides a dry anaerobic fermentation device, which includes a housing 1, a stirring mechanism 2, a temperature detector 3, a heating mechanism 4, a biogas slurry flow detector 5 and a biogas flow detector 6. The stirring mechanism 2 is rotatably connected inside the housing 1, and the heating mechanism 4 is installed at the stirring end of the stirring mechanism 2 for heating the fermentation materials during the stirring process. The temperature detector 3 is installed inside the housing 1 to detect the temperature change inside the housing 1. An air outlet 11 is provided on the top surface of the housing 1 for conveying the biogas generated during the fermentation process, and a return port 12 is provided at the bottom of the housing 1 for returning the biogas slurry to increase the necessary biological growth matrix during the anaerobic fermentation process. Since it is necessary to maintain the fermentation temperature during the anaerobic fermentation process and heat is generated during the fermentation process, therefore, the returned biogas slurry and the conveyed biogas will carry away a part of the heat. Therefore, the biogas slurry flow detector 5 is installed at the return port 12 to detect the amount of the returned biogas slurry, and the biogas flow detector 6 installed at the air outlet 11 also detects the amount of the conveyed biogas. The heating mechanism 4 adjusts the heating efficiency according to the detection results of the biogas slurry flow detector 5 and the biogas flow detector 6, so as to ensure that the temperature inside the housing 1 will not change greatly, thereby affecting the fermentation efficiency. At the same time, the temperature detector 3 is used to detect the temperature change inside the housing 1, and the heating mechanism 4 further adjusts the heating efficiency according to the detection result of the temperature detector 3, so as to ensure that the temperature inside the housing 1 can be unaffected by the returned biogas slurry and the conveyed biogas, maintain the temperature stability inside the housing 1, and avoid the situation that the change in temperature causes the reduction of the fermentation efficiency.

[0023] During the anaerobic fermentation process, biogas is generated, and this generated biogas is usually used for biogas power generation. During the biogas power generation process, exhaust gas is discharged, and the discharged exhaust gas carries heat. Therefore, to avoid waste, this part of the waste heat is used for heating during the anaerobic fermentation process, thereby reducing resource waste. However, this part of the waste heat cannot be directly input into the housing 1 for heating, but instead circulates outside the housing 1 to reduce heat loss inside the housing 1. Therefore, in order to reduce waste heat waste and improve the heating efficiency inside the housing 1, in this embodiment, the stirring mechanism 2 includes a stirring shaft 21 and stirring blades 22. The stirring shaft 21 is rotatably connected inside the housing 1 and is horizontally placed. The stirring blades 22 are spiral and are installed on the outer side wall of the stirring shaft 21. Flow channels 23 are provided inside both the stirring shaft 21 and the stirring blades 22, and a heat flow medium flows in the flow channels 23. The heating mechanism 4 is embedded in the outer side wall of the stirring blades 22. By providing flow channels 23 inside the stirring shaft 21 and the stirring blades 22 and allowing the waste heat generated by biogas power generation to flow as the heat flow medium in the flow channels 23, the temperature on the stirring blades 22 is increased, so that the stirring blades 22 can better heat the materials during the stirring process, avoiding the situation where the fermentation efficiency is low due to uneven heating during the fermentation process. Moreover, since the stirring blades 22 are spiral and horizontally placed, during the stirring process, the stirring blades 22 will turn the materials at the bottom of the housing 1 to the top, making the fresh materials and inoculated materials evenly mixed, thereby improving the fermentation efficiency.

[0024] To better guide the heat flow medium to flow inside the stirring blades 22 and enable the heat flow medium to transfer heat more effectively, in one embodiment, the stirring blades 22 are composed of upper stirring blades and lower stirring blades. The upper stirring blades are fitted on the top surface of the lower stirring blades to form the lower stirring blades. Grooves are correspondingly provided on the fitting surfaces of the upper stirring blades and the lower stirring blades. The two grooves form the flow channel 23. By providing grooves on the fitting surfaces of the upper stirring blades and the lower stirring blades, and the shape and depth of the grooves can be optimized to ensure that during the stirring operation, the fluid can be evenly distributed and the eddy current phenomenon can be reduced, thereby improving the flow efficiency and ensuring the full stirring of the fermented substances and the even distribution of heat.

[0025] In order to better heat the materials in the housing 1 evenly, in one embodiment, the heating mechanism 4 includes an electromagnetic heater. An electromagnetic heating layer is embedded on both the upper and lower surfaces of the stirring blade 22. The electromagnetic heater is electrically connected to the electromagnetic layer. Since the electromagnetic heater uses a high-frequency electromagnetic field to generate heat in the metal material, through the method of electromagnetic induction heating, it can quickly and evenly heat the materials, reduce heat loss, and the electromagnetic heater has a fast response speed and can quickly adjust the heating power according to the needs of the system to ensure that the fermentation process remains within the optimal temperature range. At the same time, since the electromagnetic heating layer is embedded on the upper and lower surfaces of the stirring blade 22, it can effectively transfer the heat to the materials being stirred and ensure uniform heat distribution in the heating area, avoiding local overheating or overcooling, thereby improving the heating effect of the materials.

[0026] In order to reduce the energy loss of the electromagnetic heater, improve the energy conversion efficiency, and thus reduce heat waste, in one embodiment, the electromagnetic heating layer is made of silicon steel material. Due to the high magnetic permeability of the silicon steel material, it can effectively concentrate and conduct the electromagnetic field, enhancing the efficiency of electromagnetic heating. Moreover, the thermal conductivity of the silicon steel material enables the electromagnetic heating layer to quickly conduct the generated heat to the stirring blade 22 and the surrounding materials, improving the heating effect.

[0027] In order to improve the service life of the stirring blade 22 and protect the surface of the electromagnetic heating layer at the same time, avoiding the reduction of heat conduction performance caused by corrosion, in one embodiment, a corrosion-resistant layer is coated on the surface of the electromagnetic heating layer. By coating the corrosion-resistant layer on the surface, it can avoid the reduction of heat conduction performance caused by corrosion, reduce the maintenance frequency of the equipment, lower the maintenance cost, and improve the overall operation efficiency.

[0028] In order to better and precisely control the heating efficiency of the heating mechanism 4, in one embodiment, the heating mechanism 4 further includes a temperature control system. The temperature control system is provided with a heating control algorithm. The temperature control system adjusts the heating efficiency based on the detection results of each detector and the heating control algorithm. The set parameters of the heating control algorithm are: T_target: target temperature; T: current temperature; ΔT: temperature adjustment threshold; Q_liquid: current biogas slurry flow rate; Q_liquid_target: target biogas slurry flow rate; Q_gas: current biogas flow rate; Q_gas_target: target biogas flow rate; P_base: basic heating power; P_max: maximum heating power; P_min: minimum heating power; k1, k2, k3, k4, k5: adjustment coefficients. Among them, when controlling the heating efficiency of the heating mechanism 4, the current temperature T is read through temperature detection and the temperature deviation is calculated: ΔT_temp = T_target - T;

[0029] Then the heating power is adjusted according to the deviation value: P_adjust_temp = k1 * ΔT_temp;

[0030] Meanwhile, according to the currently read biogas slurry flow rate \(Q_{liquid}\) and biogas flow rate \(Q_{gas}\), and the cumulative flow rate within the output time \(t\):

[0031] Cumulative biogas slurry flow rate = \(\int_{}^{}Q_{liquid}(t)dt\);

[0032] Determine the relationship between the cumulative flow rate and the target flow rate:

[0033] \(\Delta Q_{liquid}=Q_{liquid}-Q_{liquid\_target}\);

[0034] Similarly, the calculation formula for the biogas flow rate is:

[0035] \(\Delta Q_{gas}=Q_{gas}-Q_{gas\_target}\);

[0036] Then adjust the heating power according to the biogas slurry flow rate:

[0037] \(P_{adjust\_liquid}=\begin{cases}k_2\times\Delta Q_{liquid}, & \text{if}Q_{liquid}<Q_{liquid\_target}\\ -k\times3\Delta Q_{liquid}, & \text{if}Q_{liquid}>Q_{liquid\_target}\end{cases}\);

[0038]

[0039] Through the heating algorithm in the temperature control system, the changes in real-time temperature, biogas slurry flow rate, and biogas flow rate are used to dynamically adjust the heating efficiency, thereby optimizing the effect of the anaerobic fermentation process and improving the stability and efficiency of the anaerobic fermentation process.

[0040] In one embodiment, in order to accurately detect the amount of biogas slurry flowing back, the biogas slurry flow rate detector 5 is an electromagnetic flowmeter. Since the electromagnetic flowmeter utilizes Faraday's law of electromagnetic induction, when the fluid passes through the magnetic field, the flow of the fluid will generate an electromotive force. By measuring the magnitude of the electromotive force, the flow rate can be calculated. Therefore, the electromagnetic flowmeter is not affected by the density and temperature of the liquid, thus better detecting the flow rate of the biogas slurry and avoiding the occurrence of deviations in the heating efficiency of the heating mechanism 4 due to detection errors.

[0041] In one embodiment, in order to accurately detect the amount of biogas output, the biogas flow rate detector 6 is a mass flowmeter. The mass flowmeter directly measures the mass flow rate of the gas by measuring the mass flow of the gas passing through the sensor. At the same time, it can also measure the density and temperature simultaneously, enabling efficient and accurate flow monitoring and avoiding measurement errors caused by changes in gas density.

[0042] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments with equivalent changes within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A dry anaerobic fermentation device, characterized in that: The invention comprises a shell, a stirring mechanism, a temperature detector, a heating mechanism, a biogas flow detector and a biogas flow detector. The stirring mechanism is rotatably connected to the inside of the shell. The heating mechanism is installed at the stirring end of the stirring mechanism. The temperature detector is installed at the inner wall of the shell and detects the temperature change in the shell. A gas supply port is provided on the top surface of the shell, and a reflux port is provided on the bottom. The biogas flow detector is installed at the reflux port and detects the reflux flow of the reflux port. The biogas flow detector is installed at the gas supply port and detects the gas supply volume of the gas supply port. The heating mechanism adjusts the heating efficiency according to the detection results of the biogas flow detector and the detection results of the biogas detector, and at the same time, the heating efficiency is secondary adjusted according to the temperature change trend of the temperature detector within a preset time interval.

2. A dry anaerobic fermentation device according to claim 1, characterized in that: The stirring mechanism includes a stirring shaft and a stirring blade. The stirring shaft is rotatably connected to the shell and placed horizontally. The stirring blade is spirally shaped and installed on the outer wall of the stirring shaft. Both the stirring shaft and the stirring blade are provided with flow channels, and a heat flow medium flows in the flow channels. The heating mechanism is embedded in the outer wall of the stirring blade.

3. A dry anaerobic fermentation device according to claim 2, characterized in that: The stirring blade consists of an upper stirring blade and a lower stirring blade. The upper stirring blade is embedded in the top surface of the lower stirring blade to form the lower stirring blade. The surfaces where the upper stirring blade and the lower stirring blade are embedded are correspondingly provided with grooves, and the two grooves constitute a flow channel.

4. A dry anaerobic fermentation device according to claim 1, characterized in that: The heating mechanism comprises an electromagnetic heater, and an electromagnetic heating layer is embedded on the upper and lower surfaces of the stirring blade, and the electromagnetic heater is electrically connected to the electromagnetic layer.

5. A dry anaerobic fermentation device according to claim 4, characterized in that: The electromagnetic heating layer is made of silicon steel material.

6. A dry anaerobic fermentation device according to claim 4, characterized in that: The surface of the electromagnetic heating layer is coated with a corrosion-resistant layer.

7. A dry anaerobic fermentation device according to claim 1, characterized in that: The heating mechanism also includes a temperature control system, in which a heating control algorithm is provided. The temperature control system regulates the heating efficiency through the detection results of each detector and the heating control algorithm.

8. The dry anaerobic fermentation device according to claim 1, characterized in that: The biogas slurry flow detector is an electromagnetic flow meter.

9. The dry anaerobic fermentation device according to claim 1, characterized in that: The biogas flow detector is a mass flow meter.

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