High-temperature solid anaerobic fermentation equipment matched with gas pulse stirring

Abstract

The invention relates to high-temperature solid anaerobic fermentation equipment matched with gas pulse stirring, which comprises a closed box body, the interior of the closed box body is vertically divided into a fermentation space and a heating space by a transmission device, and the top of the fermentation space is provided with a feed pipe and an exhaust port which are provided with valves; the top of the feeding pipe is located outside, the bottom of the feeding pipe is located above the material level of the fermentation space, a plurality of gas pulse devices used for stirring materials in an air-blowing mode are communicated with the position, above the transmission device, in the fermentation space, and a discharging device for discharging solid materials is further arranged on one side of the bottom of the fermentation space; the heating space is used for receiving biogas slurry discharged from the fermentation space, a heating device is arranged in the heating space, and the heating space is communicated with the fermentation space through a pump set. According to the equipment, a high-temperature environment of solid anaerobic fermentation can be maintained on the basis of greatly reducing energy consumption, meanwhile, slag and liquid are convenient to separate, the loss of microbial colonies is small, dynamic and stable operation of anaerobic fermentation is ensured, and the proportion of methane in obtained biogas is increased.

Description

Technical Field

[0001] The invention belongs to the technical field of biomass anaerobic fermentation, and in particular relates to high-temperature solid anaerobic fermentation equipment with gas pulse stirring. Background Art

[0002] At present, the anaerobic fermentation technology of biomass is basically divided into two methods: wet anaerobic fermentation and high-temperature solid fermentation. The former has a higher moisture content in the fermentation substrate and requires a larger reactor volume and higher energy consumption to heat the substrate. Therefore, it is subject to more restrictions in the actual application process. At the same time, the process will also produce more biogas slurry, further increasing the cost investment of fermentation waste liquid treatment; the latter has a solid content of more than 15% in the fermentation material, and the overall flowing water content is extremely low and fermented in a high-temperature fermentation environment above 45°C. It has the advantages of higher gas production per unit volume, less energy consumption required for heating, less reactor volume and less biogas slurry to be treated, and can also achieve a higher organic load rate. At the same time, the biogas residue produced by the high-temperature solid anaerobic fermentation process is suitable for use as fertilizer or fuel due to its lower moisture content, and can also generate economic benefits. However, no matter which method is used, the separation and treatment of biogas slurry and biogas residue are relatively difficult, and the direct discharge or treatment of biogas residue and biogas slurry also leads to the continuous loss of bacterial colonies in the fermentation equipment, so it is necessary to continuously add inoculants to keep the fermentation running continuously, thereby increasing the comprehensive management cost of equipment operation. Moreover, high-temperature solid fermentation itself has poor fluidity, and relying solely on mechanical stirring consumes a lot of energy, resulting in a low overall net power output of the equipment. Summary of the invention

[0003] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a high-temperature solid anaerobic fermentation equipment with gas pulse stirring. The equipment can maintain a high-temperature environment for solid anaerobic fermentation on the basis of greatly reducing energy consumption. At the same time, the slag and liquid are separated conveniently and the loss of microbial colonies is small, thereby ensuring the dynamic and stable operation of anaerobic fermentation and increasing the proportion of methane content in the obtained biogas.

[0004] To achieve the above object, the present invention provides the following technical solutions: A high-temperature solid anaerobic fermentation equipment with gas pulse stirring, the equipment comprises a closed box, and the interior of the closed box is divided into a fermentation space and a heating space by a transmission device at the top and bottom, a feed pipe and an exhaust port equipped with a valve are arranged on the top of the fermentation space, the top of the feed pipe is located outside and the bottom is located above the material level of the fermentation space, the inside of the fermentation space is connected to a plurality of gas pulse devices for air blowing and stirring materials above the transmission device, and a discharge device for discharging solid materials is also arranged on one side of the bottom of the fermentation space; The heating space is used to receive the biogas slurry discharged from the fermentation space and a heating device is arranged in the heating space, and the heating space is connected to the fermentation space through a pump set. The transmission device can prevent solid materials from entering the heating space from the fermentation space, but the biogas slurry in the fermentation space can pass through the transmission device and enter the heating space.

[0005] Preferably, the transmission device is a chain scraper device that transmits horizontally in the direction of the discharge device.

[0006] Preferably, the discharge device comprises a discharge bin connected to the fermentation space and isolated from the heating space, the discharge bin inlet is not higher than the chain scraper device, and a shaftless screw conveyor arranged horizontally and perpendicular to the chain scraper device is provided above the discharge bin feed port; The discharge device also includes an inclined screw extruder, and the feed port of the screw extruder is located at the discharge port of the discharge bin. The discharge bin is not connected to the heating space to prevent the biogas slurry in the heating space from being discharged through the discharge bin, but part of the biogas slurry in the fermentation space will flow into the discharge bin, and the materials entering the discharge bin will also carry part of the biogas slurry, so the staff can set a biogas slurry collection device at the bottom of the discharge bin according to actual application, which can be discharged back into the heating space after subsequent treatment, or it can be used as an organic fertilizer raw material with biogas residue.

[0007] Preferably, the pump group includes a reflux pipe connecting the fermentation space and the heating space, the reflux pipe is equipped with a reflux pump and an electromagnetic flowmeter, and the top of the reflux pipe is arranged in the fermentation space and above the material level, and a plurality of spray ports are opened on the pipe body.

[0008] Preferably, the heating device is an electric heating rod powered by green energy and / or a heat exchange tube structure into which a heat medium is introduced. The green energy includes but is not limited to electricity converted from clean energy such as light energy and wind energy; the heat medium can be geothermal water or hot wastewater generated in other production process links.

[0009] Preferably, the gas pulse device comprises a plurality of bronchi extending from a parallel transmission device, wherein the bronchi are arranged below the material level and are arranged from high to low relative to each other.

[0010] Preferably, the bronchus is provided with an air jet hole exposed to the fermentation space, and one end of the bronchus located outside is provided with a ball valve and connected to one end of the main air pipe respectively; The other end of the main air pipe is sequentially provided with a solenoid valve and a supercharger and is connected to an air source, and the air source is connected to the exhaust port.

[0011] The dynamic fermentation method using the high temperature solid anaerobic fermentation equipment with gas pulse stirring is as follows: 1) Mixing the pretreated fermentation material with the digestate after material fermentation, and then feeding the mixture into a fermentation space at 42-55°C from a feed pipe at regular intervals; 2) The main air pipe pressurizes the biogas and then blows pulse air to stir the materials in the fermentation space through the jet holes of the bronchial pipe. The pressure of the biogas discharged from the jet holes is 0.1-0.6MPa; 3) The biogas slurry produced in the fermentation space flows back to the heating space after passing through the chain scraper device. The heating device maintains the biogas slurry temperature in the heating space at 50-60℃. The reflux pump and the spray port on the reflux pipe spray the biogas slurry in the heating space onto the material. 4) The chain scraper device transmits the material at the bottom of the fermentation space to the shaftless screw conveyor, and the shaftless screw conveyor transmits the material to the discharge bin. After the material is squeezed and drained by the screw extruder, it is transported to the outside and used as biogas residue.

[0012] Furthermore, the fermentation material is composed of a mixture of one or more organic matter such as garden waste, crop straw, and livestock and poultry manure, and the solid content of the mixture of the pretreated fermentation material and biogas residue is 20-40%.

[0013] Furthermore, the volume vacancy rate of the internal space of the sealed box is 20-40%. Compared with the prior art, the present invention has the following advantages: 1) The heating load of the whole machine is small: Temperature is one of the important factors that affect the activity of microbial enzymes, and the processing capacity of anaerobic fermentation will decrease significantly as the temperature decreases. Therefore, in order to maintain a high fermentation efficiency, the temperature of the fermentation environment needs to be kept above 45°C. This application adopts the method of heating the circulating biogas slurry separately instead of heating the entire reaction substrate, which greatly reduces the heat load and energy consumption of the whole machine; at the same time, the biogas slurry rich in microorganisms can be sprayed and efficiently contact the material, thereby achieving the effect of high temperature and high efficiency fermentation.

[0014] 2) Dynamic fermentation has high efficiency and low loss of microorganisms: The biogas slurry in this application can be recycled, and the discharged biogas residue will also serve as a component of the subsequent fermentation substrate and will carry the microorganisms to participate in the fermentation again, thereby achieving the enrichment and domestication of the anaerobic fermentation flora, promoting the efficient fermentation, and eliminating the need to add microorganisms multiple times, thereby reducing the overall management cost.

[0015] 3) Dynamic fermentation quickly separates slag and liquid: The biogas slurry generated by the substrate in the fermentation space can be immediately discharged into the heating space, thereby realizing the separation of solid materials and biogas slurry. At the same time, the biogas slurry will also be circulated and sprayed on the solid materials. Therefore, on the basis of ensuring the humidity demand of the fermentation environment, the humidity balance of the discharged materials is ensured, thereby reducing the difficulty of squeezing and separating the subsequent materials from the biogas slurry.

[0016] 4) The mixed disturbance effect of pulse air blowing and transmission device has low energy consumption and good effect: The present application blows the biogas generated by fermentation to the material in pulses after pressurization. On the one hand, the oxygen introduced in the dynamic feeding process can be discharged to ensure an anaerobic environment. On the other hand, the high-pressure pulse gas can effectively impact the material to achieve disturbed mixing of the material. At the same time, the present application sets a chain scraper device at the bottom of the fermentation space to discharge the fermented material at the bottom, which can also achieve disturbed mixing of the material. The present application has no mechanical stirring operation as a whole, which improves the stability of the equipment operation.

[0017] 5) Simple and controllable operation: The present application can achieve coordinated management between the return flow of biogas slurry and the fermentation materials through the control of the solenoid valve, effectively control the solid content of the fermentation materials in the box, and reasonably regulate the rate of anaerobic fermentation.

[0018] 6) The circulating gas blowing of biogas in the fermentation space can increase the methane content in the final gas: The pulse air blowing of the present application adopts the obtained biogas as the gas source and realizes its circulation flow in the fermentation space. In this way, the gas source can make the fermentation material adsorb gases such as carbon dioxide in the gas source on the basis of sufficient contact with the fermentation material, and finally carry the gas to the outside in the form of biogas residue, thereby achieving the purification effect of the gas source, that is, increasing the methane content in the final biogas obtained, thereby reducing the subsequent biogas purification and processing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of the high-temperature solid anaerobic fermentation device described in a specific implementation method. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] like Figure 1 As shown, a high-temperature solid anaerobic fermentation equipment with gas pulse stirring comprises a closed box 1, wherein the closed box 1 is divided into a fermentation space 6 and a heating space 2 by a chain scraper device 5 extending horizontally. A feed pipe 9 equipped with a valve 8 and an exhaust port 13 are provided at the top of the fermentation space 6, wherein the top of the feed pipe 9 is located outside and the bottom is located above the material level of the fermentation space 6; The closed box 1 is provided with a plurality of bronchial pipes 151 extending from parallel transmission devices at a position between the chain scraper device 5 and the high point of the material level. The bronchial pipes 151 are arranged from high to low with respect to each other. The bronchial pipes 151 are provided with jet holes 152 exposed to the fermentation space, and the bronchial pipes 151 are provided with a ball valve 13 at one end of the outside and are respectively connected to one end of the main air pipe 15, and the other end of the main air pipe 15 is sequentially provided with a solenoid valve 154 and a supercharger and connected to the air source.

[0022] The heating space 2 is used to receive the biogas slurry discharged from the fermentation space 6 and is provided with an electric heating rod and a heat exchange pipe structure 18 for introducing heat medium. A reflux pipe 7 equipped with a reflux pump 3 and an electromagnetic flowmeter connects the fermentation space 6 and the heating space 2, and the top of the reflux pipe 7 is arranged in the fermentation space 6 and is located above the material level. A plurality of spray ports 10 are opened on the pipe body.

[0023] A discharge device for discharging solid materials is also provided on one side of the bottom of the fermentation space 6, including a discharge bin connected to the fermentation space 6 and isolated from the heating space 2, the inlet of the discharge bin is not higher than the chain scraper device 5, and a shaftless screw conveyor 16 arranged horizontally and perpendicular to the chain scraper device 5 is provided above the feed inlet of the discharge bin; The discharge device further comprises a screw extruder 17 which is arranged obliquely, and the feed port of the screw extruder 17 is arranged at the discharge port of the discharge bin.

[0024] The dynamic fermentation method using the high temperature solid anaerobic fermentation equipment with gas pulse stirring is as follows: 1) Mix the pretreated fermentation material with the biogas residue after material fermentation and ensure that the solid content of the mixture is 20-40%, then feed the mixture into the fermentation space from the feed pipe with the valve opened at regular intervals, close the valve of the feed pipe immediately after the feeding is completed, and the mixture is fermented at high temperature in the fermentation space. At the same time, the valve of the exhaust port is opened regularly to discharge the biogas generated during the fermentation process and collect it as the gas source for pulse air blowing: the main air pipe pressurizes the biogas as the gas source and then performs pulse air blowing and stirring on the material in the fermentation space through the jet hole of the bronchus, and the pressure of the biogas discharged from the jet hole is 0.1-0.6MPa; 2) The biogas slurry produced in the fermentation space flows back to the heating space after passing through the chain scraper device. The heating device maintains the biogas slurry temperature in the heating space at 50-60°C. The reflux pump and the spray port on the reflux pipe spray the biogas slurry in the heating space onto the material and maintain the ambient temperature in the fermentation space at 42-55°C. 3) The chain scraper device continuously transmits the material at the bottom of the fermentation space (i.e., the substrate after the reaction is completed) to the shaftless screw conveyor, and the shaftless screw conveyor transmits the material to the discharge bin, and the material is extruded and drained by the screw extruder and then transported to the outside and used as biogas residue.

Claims

1. A high-temperature solid anaerobic fermentation equipment with gas pulse stirring, characterized in that: The device comprises a closed box, and the interior of the closed box is divided into a fermentation space and a heating space by a transmission device at the top and bottom. A feed pipe and an exhaust port equipped with a valve are provided at the top of the fermentation space. The top of the feed pipe is located outside and the bottom is located above the material level of the fermentation space. The interior of the fermentation space is connected to a plurality of gas pulse devices for air blowing and stirring materials above the transmission device. A discharge device for discharging solid materials is also provided at one side of the bottom of the fermentation space. The heating space is used to receive the biogas slurry discharged from the fermentation space and a heating device is arranged in the heating space. The heating space is connected with the fermentation space through a pump group.

2. The high-temperature solid anaerobic fermentation equipment with gas pulse stirring as claimed in claim 1, characterized in that: The transmission device is a chain scraper device that transmits horizontally in the direction of the discharging device.

3. The high temperature solid anaerobic fermentation equipment with gas pulse stirring as claimed in claim 2, characterized in that: The discharge device comprises a discharge bin connected to the fermentation space and isolated from the heating space, the discharge bin inlet is not higher than the chain scraper device, and a shaftless screw conveyor arranged horizontally and perpendicular to the chain scraper device is provided above the discharge bin feed port; The discharge device also includes a screw extruder that is arranged obliquely, and the feed port of the screw extruder is arranged at the discharge port of the discharge bin.

4. The high-temperature solid anaerobic fermentation equipment with gas pulse stirring as claimed in claim 1, characterized in that: The pump group includes a reflux pipe connecting the fermentation space and the heating space, the reflux pipe is equipped with a reflux pump and an electromagnetic flowmeter, and the top of the reflux pipe is arranged in the fermentation space and a plurality of spray ports are opened on the pipe body above the material level.

5. The high temperature solid anaerobic fermentation equipment with gas pulse stirring as claimed in claim 1, characterized in that: The heating device is an electric heating rod powered by green energy and / or a heat exchange pipe structure into which a heat medium is passed.

6. The high-temperature solid anaerobic fermentation equipment with gas pulse stirring as claimed in claim 1, characterized in that: The gas pulse device comprises a plurality of bronchial tubes extending from a parallel transmission device, wherein the bronchial tubes are arranged below the material level and are arranged from high to low.

7. The high-temperature solid anaerobic fermentation equipment with gas pulse stirring as claimed in claim 6, characterized in that: The bronchus is provided with an air jet hole exposed to the fermentation space, and one end of the bronchus located outside is equipped with a ball valve and connected to one end of the main air pipe respectively; The other end of the main air pipe is sequentially provided with a solenoid valve and a supercharger and is connected to an air source, and the air source is connected to the exhaust port.

8. A dynamic fermentation method using the high temperature solid anaerobic fermentation equipment with gas pulse stirring as described in any one of claims 1 to 7, characterized in that: Here are the steps: 1) Mixing the pretreated fermentation material with the digestate after material fermentation, and then feeding the mixture into a fermentation space at 42-55°C from a feed pipe at regular intervals; 2) The main air pipe pressurizes the biogas and then blows pulse air to stir the materials in the fermentation space through the jet holes of the bronchial pipe. The pressure of the biogas discharged from the jet holes is 0.1-0.6MPa; 3) The biogas slurry produced in the fermentation space flows back to the heating space after passing through the chain scraper device. The heating device maintains the biogas slurry temperature in the heating space at 50-60℃. The reflux pump and the spray port on the reflux pipe spray the biogas slurry in the heating space onto the material. 4) The chain scraper device transmits the material at the bottom of the fermentation space to the shaftless screw conveyor, and the shaftless screw conveyor transmits the material to the discharge bin. After the material is squeezed and drained by the screw extruder, it is transported to the outside and used as biogas residue.

9. The dynamic fermentation method according to claim 8, characterized in that: The fermentation material is composed of a mixture of one or more organic matter such as garden waste, crop straw, and livestock and poultry manure. The solid content of the mixture of the pretreated fermentation material and biogas residue is 20-40%.

10. The dynamic fermentation method according to claim 8, characterized in that: The volume vacancy rate of the inner space of the closed box is 20-40%.

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