Stirring blade distributed high-concentration manure straw methane production device

Abstract

The utility model discloses a high-concentration manure straw methane production device with distributed stirring blades. The high-concentration manure straw methane production device comprises a support, a fermentation tank body and a stirring assembly, wherein the fermentation tank body is arranged on the support and is provided with a heat preservation structure, and the stirring assembly is arranged in the fermentation tank body and adopts an intermittent stirring mode. The stirring assembly comprises a driving part arranged at the top of the fermentation tank body, a stirring shaft which is connected to the output end of the driving part and extends into the fermentation tank body, and stirring blades mounted on the stirring shaft. And the stirring blades are non-uniformly distributed along the axial direction of the stirring shaft to form an upper high-density stirring area and a lower low-density stirring area. The device is reliable in structure, the integrated intermittent stirring blades which are dense at the upper part and sparse at the lower part are adopted, the mixing efficiency is improved, and meanwhile, the dense stirring blades at the upper part prevent scum formation, promote gas release and enhance gas-liquid separation; the lower sparse stirring blades avoid excessive stirring of the sludge at the bottom, maintain the stability of the anaerobic granular sludge, and prevent tiny biogas bubbles from being re-dissolved in a liquid phase due to excessive stirring.

Description

Technical Field

[0001] This utility model relates to the technical field of methane production equipment, specifically to a high-concentration manure-straw methane production device with distributed stirring blades. Background Technology

[0002] Methanogenesis in the anaerobic fermentation of organic matter involves two processes: bacterial hydrolysis and acidification, and archaea methanogenesis. These two microbial metabolic processes have different oxygen requirements. Hydrolysis and acidification are best suited for microaerobic conditions, while methanogenesis requires a strictly anaerobic environment. Traditional stirring devices use vertically aligned, uniform blades, focusing more on homogenizing the fermentation material and neglecting the heterogeneity of these two metabolic processes. This makes it difficult to achieve spatial independence between the hydrolysis / acidification phase and methanogenesis in high-concentration manure-straw anaerobic fermentation.

[0003] While traditional vertical agitator structures can promote material mixing, they haven't optimized blade layouts for the stratification characteristics of high-concentration manure and straw. Some studies have attempted to use segmented agitators for mixing, but blade density and function haven't been integrated with zoned temperature control. Helical propeller agitators use rotating helical blades to propel material axially, making them suitable for high-viscosity materials. However, traditional helical propellers typically have uniformly distributed blade density, failing to optimize for the acidified and methanogenic phases of high-concentration manure and straw. Furthermore, under a single mixing intensity, high-solids-content straw is prone to acidification imbalance, leading to a decrease in methane yield. Utility Model Content

[0004] To solve the above-mentioned technical problems, this utility model provides a high-concentration manure-straw methane production device with distributed stirring blades.

[0005] The technical solution of this utility model is as follows: a high-concentration manure-straw methanogenizing device with distributed stirring blades, including a support, a fermentation tank with a heat-insulating structure installed on the support, and a stirring component installed in the fermentation tank and using an intermittent stirring method;

[0006] The stirring assembly includes a drive unit located at the top of the fermentation tank, a stirring shaft that is fitted to the output end of the drive unit and extends into the interior of the fermentation tank, and stirring blades located on the stirring shaft. The stirring blades are non-uniformly distributed along the axial direction of the stirring shaft, forming an upper high-density stirring zone and a lower low-density stirring zone.

[0007] Furthermore, the stirring blades include multiple laterally curved blade units, the bending direction of which is consistent with the rotation direction of the stirring shaft.

[0008] Furthermore, multiple blade units are staggered from top to bottom along the stirring shaft.

[0009] Furthermore, in the circumferential direction of the stirring shaft, the size of the stirring blades gradually decreases along its rotation direction.

[0010] Furthermore, the insulation structure includes an insulation shell that is sealed and covers the outside of the fermenter and has an internal cavity, and an insulation medium injection port that is provided on the insulation shell and communicates with the cavity.

[0011] Furthermore, the top of the fermentation tank is equipped with an oxygen delivery pipe, a feed inlet, and a biogas outlet.

[0012] Furthermore, an oxygen concentration detector is installed on the top of the fermentation tank to detect oxygen concentration.

[0013] The beneficial effects of this invention are as follows: The device has a reliable structure and adopts an integrated intermittent stirring blade with a "dense upper section and sparse lower section" design, which improves mixing efficiency. The high-density stirring zone at the top prevents scum formation, promotes gas release, and enhances gas-liquid separation; the low-density stirring zone at the bottom avoids excessive agitation of the bottom sludge, maintains the stability of the anaerobic granular sludge, and prevents tiny biogas bubbles from redissolving in the liquid phase due to excessive agitation. In addition, this design spatially enhances the two-phase zoned reaction, with intermittent stirring slowly advancing the lower region, which is beneficial to the activity of slowly growing methanogenic bacteria, thereby improving methanogenesis efficiency. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of this utility model;

[0015] Figure 2 This is an isometric view of the stirring shaft and stirring blades in this utility model;

[0016] Figure 3 This is a top view of the stirring shaft and stirring blades of this utility model;

[0017] Figures 1 to 3 The reference numerals in the attached drawings are respectively: 1-support, 2-fermentation tank body, 3-stirring assembly, 30-drive component, 31-stirring shaft, 32-stirring blade, 320-blade unit, 33-high-density stirring zone, 34-low-density stirring zone, 4-insulation shell, 5-insulation medium injection port, 20-oxygen delivery pipe, 21-feed inlet, 22-biogas outlet. Detailed Implementation

[0018] The principles and features of this utility model are described below with reference to the accompanying drawings. The examples given are for explaining this utility model and are not intended to limit the scope of this utility model.

[0019] like Figures 1 to 3As shown, this high-concentration manure-straw methanogenic device with distributed stirring blades includes a support 1, a fermentation tank 2 mounted on the support 1 and equipped with a heat-insulating structure, and a stirring assembly 3 installed inside the fermentation tank 2 using an intermittent stirring method. The support 1 provides stable support for the entire device, bearing the weight of the fermentation tank 2 and the stirring assembly 3, and isolates it from ground vibrations or external interference, ensuring stable operation of the device. The fermentation tank 2, as the core container for the anaerobic fermentation reaction, provides a sealed environment for the acidification and methanogenic process of high-concentration manure-straw. Its heat-insulating structure is used to maintain a stable temperature inside the tank, reduce heat loss, ensure efficient metabolism of anaerobic bacteria (especially methanogenic bacteria) at a suitable temperature, and simultaneously isolate oxygen to meet the strict anaerobic conditions of the methanogenic stage.

[0020] The stirring assembly 3 promotes material mixing and optimizes reaction conditions through intermittent stirring, while avoiding excessive disturbance that could damage the anaerobic environment. Preferably, the stirring assembly 3 includes a drive component 30 (such as a motor) located at the top of the fermenter 2, a stirring shaft 31 connected to the output end of the drive component 30 and extending into the fermenter 2, and stirring blades 32 mounted on the stirring shaft 31. The stirring blades 32 are non-uniformly distributed along the axial direction of the stirring shaft 31, forming an upper high-density stirring zone 33 and a lower low-density stirring zone 34. This "dense at the top and sparse at the bottom" intermittent stirring structure enhances the acidification and anaerobic fermentation processes, further utilizing the partitioned reaction conditions of low oxygen at the top and anaerobic at the bottom, while preventing the upper material from agglomerating and improving the effect of the upper acidification process, thereby increasing the methanogenesis efficiency.

[0021] Specifically, a drive unit 30 (such as a motor) provides power to drive the stirring shaft 31 to rotate, achieving the stirring function. The stirring requirements of different reaction stages can be adapted through frequency conversion or intermittent control. The stirring shaft 31 transmits driving force and supports the stirring blades 32, extending to the bottom of the tank to ensure effective stirring in both the upper and lower areas. The stirring blades 32 are non-uniformly distributed. The dense blades in the upper high-density stirring zone 33 enhance the shear force on the surface material, preventing scum agglomeration, promoting gas-liquid mixing in the acidification stage, and maintaining a micro-aerobic environment. The sparse blades in the lower low-density stirring zone 34 reduce disturbance to the bottom sludge, protect the stability of the anaerobic granular sludge, prevent the redissolution of tiny biogas bubbles, and improve methane collection efficiency. The intermittent stirring method dynamically adapts to the aerobic characteristics of different reaction stages. In the acidification stage, which requires trace amounts of oxygen, short-term stirring promotes mixing and avoids excessive local acidification. In the strictly anaerobic methanogenic stage, the stirring frequency is reduced to maintain the anaerobic environment, which is beneficial to the slow-growing methanogenic bacteria.

[0022] Overall, the device achieves physical zoning through a "dense at the top, sparse at the bottom" blade distribution, enhancing the efficiency of the acidification and methanogenesis two-phase reactions. The synergistic effect of insulation and intermittent stirring—with the insulation stabilizing temperature and the intermittent stirring optimizing reaction kinetics—jointly improves methane yield. High-density stirring at the top prevents material caking, while low-density stirring at the bottom promotes biogas release and reduces energy loss.

[0023] Furthermore, in this embodiment, the stirring blade 32 includes multiple laterally curved blade units 320, whose bending direction is consistent with the rotation direction of the stirring shaft 31. The laterally curved blade units 320 can enhance material mixing efficiency, optimize fluid dynamics, and form vortices when rotating, promoting uniform distribution of materials in both horizontal and vertical directions, avoiding local accumulation or short-circuiting. This reduces stirring resistance, decreases contact resistance between the blades and high-concentration manure straw, reduces energy consumption, and extends equipment life; it also increases shear force, enhancing the crushing effect on scum and agglomerated materials, and preventing surface crusting. The blade bending direction being consistent with the rotation direction of the stirring shaft 31 optimizes the material flow direction, improves stirring efficiency, forms directional flow, and enhances mixing uniformity; it reduces backflow interference, avoiding energy loss caused by reverse turbulence; it promotes gas-liquid separation, guides biogas upwards, reduces bubble retention, and improves methane collection rate.

[0024] Multiple blade units 320 are staggered from top to bottom along the stirring shaft 31, which can enhance the stirring coverage and avoid stirring blind spots. The staggered arrangement makes the blades form overlapping action areas in the axial and radial directions, ensuring that there are no dead corners in the tank for mixing.

[0025] Along the circumference of the stirring shaft 31, the size of the stirring blades 32 gradually decreases in the direction of rotation. This geometric gradient can match the changes in fluid resistance during rotation. The larger blades at the front bear the main stirring load, while the smaller blades at the rear maintain flow continuity, reduce the cavitation effect of the end blades, and improve energy utilization. The larger blades preferentially break up agglomerated materials, while the smaller blades complete fine mixing, promoting a more uniform distribution of the solid-liquid-gas medium. This also reduces the fluctuation of the resistance torque at the end of rotation and lowers the motor load fluctuation.

[0026] The insulation structure includes an insulation shell 4 that is sealed and covers the outside of the fermentation tank 2 and has a cavity inside, and an insulation medium injection port 5 that is provided on the insulation shell 4 and communicates with the cavity.

[0027] An oxygen delivery pipe 20 is installed at the top of the fermentation tank 2 to regulate the micro-oxygen environment in the upper acidification zone. A small amount of oxygen is introduced in the early stage of the acidification reaction (hydrolysis stage) to promote the activity of facultative hydrolytic bacteria, accelerate the decomposition of macromolecular organic matter (such as cellulose and protein), and improve the subsequent acidification efficiency. By controlling the oxygen content, it is ensured that the oxygen only acts on the upper acidification zone and avoids diffusion to the lower methanogenic zone, which would destroy the strict anaerobic conditions.

[0028] The top of the fermentation tank 2 is also equipped with a feed inlet 21 and a biogas outlet 22. The feed inlet 21 is used to feed in the pretreated manure-straw mixture. It is located on the top of the tank using a flange or quick-connect interface to prevent the material from short-circuiting directly into the methanogenic zone and to maintain the anaerobic environment of the tank. The feed inlet 21 can be designed with multiple distribution points or equipped with a dispersion device to ensure that the material evenly covers the acidification zone and prevent local accumulation that leads to insufficient acidification. The biogas outlet 22 is used to collect the biogas (mainly composed of methane and carbon dioxide) generated in the methanogenic reaction zone and transport it to the purification and storage system through pipelines.

[0029] An oxygen concentration detector 23 is installed at the top of the fermenter 2 to detect oxygen concentration. Its functions include real-time monitoring of the oxygen concentration within the fermenter 2 to ensure strict anaerobic conditions during the methanogenesis stage; and linkage with an automation system (such as a PLC) to dynamically adjust the input of the oxygen delivery pipe 20 to prevent excessive oxygen leakage into the lower methanogenesis zone. When an abnormal oxygen concentration is detected (such as a sudden increase), an alarm is triggered or the oxygen delivery is automatically shut off to prevent the inactivation of methanogenic bacteria. The oxygen concentration detector 23 can be a German WTW Oxi 3310 (optical principle) or an American Hach LDO101 (fluorescence method), with a detection range of 0–20 mg / L and an accuracy of ±0.05 mg / L.

[0030] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A high-concentration manure-straw methanogenizing device with distributed stirring blades, characterized in that, It includes a support (1), a fermentation tank (2) with a heat preservation structure installed on the support (1), and a stirring assembly (3) installed in the fermentation tank (2) and using an intermittent stirring method. The stirring assembly (3) includes a drive unit (30) disposed on the top of the fermentation tank (2), a stirring shaft (31) connected to the output end of the drive unit (30) and extending into the interior of the fermentation tank (2), and stirring blades (32) disposed on the stirring shaft (31). The stirring blades (32) are non-uniformly distributed along the axial direction of the stirring shaft (31) to form an upper high-density stirring zone (33) and a lower low-density stirring zone (34).

2. The high-concentration manure-straw methanogenizing device with distributed stirring blades according to claim 1, characterized in that, The stirring blade (32) includes multiple transversely curved blade units (320), and the bending direction of the blade units (320) is consistent with the rotation direction of the stirring shaft (31).

3. The high-concentration manure-straw methanogenizing device with distributed stirring blades according to claim 2, characterized in that, Multiple blade units (320) are staggered from top to bottom along the stirring shaft (31).

4. The high-concentration manure-straw methanogenizing device with distributed stirring blades according to claim 3, characterized in that, In the circumferential direction of the stirring shaft (31), the size of the stirring blade (32) gradually decreases along its rotation direction.

5. The high-concentration manure-straw methanogenizing device with distributed stirring blades according to claim 1, characterized in that, The insulation structure includes an insulation shell (4) that is sealed and covered outside the fermentation tank (2) and has a cavity inside, and an insulation medium injection port (5) provided on the insulation shell (4) and communicating with the cavity.

6. The high-concentration manure-straw methanogenizing device with distributed stirring blades according to claim 1, characterized in that, The top of the fermentation tank (2) is provided with an oxygen delivery pipe (20), a feed inlet (21) and a biogas outlet (22).

7. The high-concentration manure-straw methanogenizing device with distributed stirring blades according to claim 1, characterized in that, The top of the fermentation tank (2) is equipped with an oxygen concentration detector (23) for detecting oxygen concentration.

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