Anaerobic biogas production device for kitchen waste

Abstract

The utility model discloses a kind of kitchen garbage anaerobic biogas production devices, for kitchen equipment technical field.This device includes hydrolytic acidification tank, skimming mechanism and anaerobic reactor;Hydrolytic acidification tank is used for kitchen garbage to carry out hydrolytic acidification, and the side wall of hydrolytic acidification tank is provided with residue discharge port;Skimming mechanism is arranged in hydrolytic acidification tank, and skimming mechanism is used to push the water surface scum in hydrolytic acidification tank to residue discharge port;Anaerobic reactor is communicated with hydrolytic acidification tank, and anaerobic reactor is used for kitchen garbage after hydrolytic acidification to carry out anaerobic treatment.This device separates acidification and anaerobic and is arranged in two tanks, cooperate skimming mechanism to carry out scum skimming, and the cooperation can effectively improve biogas production efficiency.

Description

Technical Field

[0001] This utility model relates to the field of kitchen waste equipment technology, and in particular to an anaerobic digester for producing biogas from kitchen waste. Background Technology

[0002] Anaerobic digestion of food waste to produce biogas is a biological treatment technology that converts food waste into biogas (mainly composed of methane CH4 and carbon dioxide CO2) and stable residue through microbial action under anaerobic conditions. This technology has the advantages of resource recovery, volume reduction and harmlessness, and is widely used in food waste treatment projects.

[0003] Anaerobic digestion can be divided into four main stages, completed collaboratively by different groups of microorganisms: hydrolysis, acidification, acetylation, and methanogenesis. Current food waste treatment devices suffer from low biogas production efficiency. A common type of device couples these four stages into a single reactor, resulting in a smaller structure and footprint. However, this leads to the coexistence and mutual restriction of microorganisms at each stage, further reducing biogas production efficiency. Another common approach separates the hydrolysis and acidification stages from the methanogenesis stage, using two tanks: one dedicated to hydrolysis and acidification, and the other to methanogenesis, thus avoiding interference. However, in current hydrolysis and acidification processes, the water surface in the tanks contains a large amount of oil and suspended solids. The oil in the water reduces microbial activity, leading to low organic matter degradation efficiency. The residue also hinders sufficient contact between microorganisms and organic matter, resulting in incomplete degradation and poor hydrolysis, thus failing to improve biogas production efficiency. Utility Model Content

[0004] This invention provides an anaerobic digester for food waste, aiming to solve the problem of low digester production efficiency in the existing technology.

[0005] This utility model provides an anaerobic digester for food waste, comprising:

[0006] A hydrolysis acidification tank is used for hydrolyzing and acidifying kitchen waste, and a slag discharge port is provided on the side wall of the hydrolysis acidification tank.

[0007] A skimming mechanism is provided inside the hydrolysis acidification tank, and the skimming mechanism is used to push the floating scum on the water surface inside the hydrolysis acidification tank toward the scum discharge port;

[0008] An anaerobic reactor is connected to the hydrolysis acidification tank, and the anaerobic reactor is used to anaerobic treat the hydrolyzed and acidified kitchen waste.

[0009] In one embodiment, the skimming mechanism includes a skimming drive, a skimming shaft, and a skimming impeller;

[0010] The skimming drive is installed on the top of the hydrolysis acidification tank, the skimming shaft is arranged along the height direction of the hydrolysis acidification tank, the skimming shaft is connected and fixed to the output shaft of the skimming drive, and the skimming impeller is connected and fixed to the skimming shaft.

[0011] The skimming drive is used to drive the skimming impeller to rotate, so that the scum on the water surface in the hydrolysis acidification tank is pushed toward the scum discharge port.

[0012] In one embodiment, the skimming impeller includes multiple blades, all of which are connected and fixed to the skimming shaft, and the blade surfaces are arranged parallel to the axis of the skimming shaft.

[0013] In one embodiment, the projection of the hydrolysis acidification tank is circular along the height direction of the hydrolysis acidification tank, and the projection size of the rotating surface of the skimming impeller matches the projection size of the hydrolysis acidification tank.

[0014] In one embodiment, the skimming mechanism includes a skimming drive, a skimming shaft, and a skimming impeller;

[0015] The skimming drive is installed on the side wall of the hydrolysis acidification tank, the skimming shaft is arranged along the diameter of the hydrolysis acidification tank, the skimming shaft is connected and fixed to the output shaft of the skimming drive, and the skimming impeller is connected and fixed to the skimming shaft.

[0016] The skimming drive is used to drive the skimming impeller to rotate, so that the scum on the water surface in the hydrolysis acidification tank is pushed toward the scum discharge port.

[0017] In one embodiment, the skimming impeller includes multiple blades, all of which are connected and fixed to the skimming shaft, with the blade surfaces facing the slag discharge port.

[0018] In one embodiment, the anaerobic digester for food waste also includes an acid-base adjustment mechanism;

[0019] The acid-base adjustment mechanism is connected to the hydrolysis acidification tank, and the acid-base adjustment mechanism is used to adjust the acidity and alkalinity in the hydrolysis acidification tank.

[0020] In one embodiment, the anaerobic digester for food waste also includes a dosing mechanism;

[0021] The dosing mechanism is connected to the anaerobic reactor and is used to add chemicals into the anaerobic reactor.

[0022] In one embodiment, the volume of the hydrolysis acidification tank is smaller than the volume of the anaerobic reaction tank.

[0023] In one embodiment, the volume ratio of the hydrolysis acidification tank to the volume of the anaerobic reaction tank is 1 / 2 to 1 / 4.

[0024] As can be seen from the above technical solutions, this utility model has the following advantages:

[0025] This embodiment provides an anaerobic digester for food waste, including a hydrolysis acidification tank, a skimming mechanism, and an anaerobic reactor. Firstly, by separately setting up the hydrolysis acidification tank and the anaerobic reactor, the hydrolysis acidification tank is used for waste undergoing the three stages of hydrolysis acidification, while the anaerobic reactor is used for waste undergoing the anaerobic reaction stage. The hydrolysis acidification stage and the methanogenesis stage are placed in two precisely designed reactors, achieving efficient functional zoning. This allows the hydrolysis acidification tank to focus on the rapid degradation of large-molecule organic matter, while the methanogenesis tank focuses on efficient gas production, effectively improving digester efficiency. Secondly, the skimming mechanism inside the hydrolysis acidification tank pushes the scum on the water surface towards the discharge port, removing oil and scum that affect microbial activity and organic matter degradation. It also reduces the scaling rate of the online device, further improving subsequent digester efficiency. Therefore, this embodiment separates acidification and anaerobic digestion into two tanks, combined with a skimming mechanism for scum removal; the combination of these two methods effectively improves digester efficiency. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the overall structure of an anaerobic digester for food waste, provided as an embodiment of the present invention.

[0028] Figure label:

[0029] Hydrolysis acidification tank 1; acidification inlet 10; acidification outlet 11; slag discharge outlet 12; slag skimming mechanism 2; slag skimming shaft 20; slag skimming impeller 21; anaerobic reaction tank 3; anaerobic inlet 30; exhaust outlet 31; acid-base adjustment mechanism 4; dosing mechanism 5; transfer pump 6. Detailed Implementation

[0030] To make the utility model's objectives, features, and advantages more apparent and understandable, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model.

[0031] Anaerobic digestion can be divided into four main stages, which are completed collaboratively by different groups of microorganisms:

[0032] 1. Hydrolysis stage

[0033] Function: Complex organic matter (such as proteins, fats, and carbohydrates) is broken down into small soluble molecules (such as amino acids, fatty acids, and monosaccharides) by hydrolytic enzymes; Microorganisms: hydrolytic bacteria (facultative or obligate anaerobic bacteria).

[0034] 2. Acidogenesis

[0035] Function: The hydrolysis products are further converted by fermenting bacteria into volatile fatty acids (VFAs, such as acetic acid and propionic acid), alcohols, H2, Products exhibit the following characteristics: pH decreases, and the system becomes acidic.

[0036] 3. Acetogenesis stage

[0037] Function: Acidification products are converted into acetic acid, H2 and CO2; Key point: This stage is sensitive to the partial pressure of H2 and needs to be maintained at a low H2 concentration in conjunction with the methanogenesis stage.

[0038] 4. Methanogenesis

[0039] Functions: Methanogens convert acetic acid, H2 / CO2, etc. into CH4 and CO2; Acetic acid cleavage: CH3COOH → CH4 + CO2 (accounting for more than 70%); Hydrogen-nutrition: 4H2 + CO2 → CH4 + 2H2O; Microorganisms: Strictly anaerobic archaea (such as Methanosaeta, Methanosarcina); Environmental requirements: pH 6.8-7.5, temperature mesophilic (35-40℃) or hyperthermic (50-55℃).

[0040] Traditional single-phase anaerobic digestion couples the four stages of hydrolysis, acidification, acetylation, and methanogenesis into a single reactor. The coexistence and mutual constraints of microorganisms at each stage result in low biogas production efficiency. The disadvantages are: 1. Mutual inhibition of the microbial community, making synergistic optimization difficult. This is because: ① Methanogens (archaea) grow slowly (doubling time 3–10 days) and are extremely sensitive to environmental changes; ② Hydrolyzing / acid-producing bacteria multiply rapidly (doubling time several hours), quickly producing acid under high load or high organic matter conditions, leading to a sharp drop in local pH (<6.0), directly inhibiting or even killing methanogens; 2. pH and alkalinity are difficult to coordinately regulate, resulting in weak system buffering capacity. The reasons are as follows: ① VFA generation and consumption occur in the same space within a single tank. When the acid production rate > methanogenesis rate, net VFA accumulation is inevitable; ② The optimal pH for methanogens is 6.8–7.5, while the optimal pH for hydrolysis and acidification is 5.0–6.0. ​​A single pH setting cannot meet the needs of both stages; ③ Alkalinity consumption occurs simultaneously with VFA generation, resulting in poor system self-regulation; 3. Hydraulic retention time (HRT) and solids retention time (SRT) cannot be optimized independently. The reasons are as follows: ① To ensure sufficient methanogen activity, a longer HRT (usually 20–30 days) is required; ② The hydrolysis and acidification stage only requires a few hours to 1–2 days. An excessively long HRT results in wasted reactor volume; ③ If the HRT is shortened to increase the load, methanogenesis will be insufficient, leading to a decrease in biogas production. ④ The HRT (High-Resolution Time) in a single tank equals the SRT (Short-Resolution Time), making it impossible to achieve the ideal model of "rapid hydrolysis with short HRT + enrichment of methanogenic bacteria with long SRT"; 4. Biogas yield and organic loading rate (OLR) are difficult to increase simultaneously. The reasons are: ① The four-stage reaction rates are mismatched: hydrolysis is the rate-limiting step, but methanogenesis is the bottleneck; ② A single tank cannot be used to separately enhance the rate-limiting stage (such as enhanced hydrolysis) (e.g., enzyme addition, heat treatment, extending the hydrolysis HRT); ③ The overall reaction efficiency is dragged down by the slowest step.

[0041] In traditional hydrolysis acidification tanks, the water surface contains a large amount of oil and suspended solids. The oil in the water reduces the activity of microorganisms, resulting in low organic matter degradation efficiency. The residue also affects the full contact between microorganisms and organic matter, leading to incomplete organic matter degradation and poor hydrolysis effect, which also fails to improve biogas production efficiency.

[0042] This utility model provides an anaerobic digester for food waste to produce biogas, which solves the technical problem of low biogas production efficiency in the prior art.

[0043] Please see Figure 1 The present invention provides an anaerobic digester for food waste, comprising:

[0044] The hydrolysis acidification tank 1 is provided with an acidification inlet 10 for feeding, an acidification outlet 11 for discharging, and a slag discharge outlet 12 for discharging slag. The acidification inlet 10 is located at the top or side wall of the acidification reaction tank, the acidification outlet 11 is located at the bottom or side wall of the acidification reaction tank, and the slag discharge outlet 12 is located on the side wall of the acidification reaction tank and is located above the acidification outlet 11. The hydrolysis acidification tank 1 is used for hydrolysis acidification of kitchen waste.

[0045] The slag skimming mechanism 2 is located inside the hydrolysis acidification tank 1. The slag skimming mechanism 2 is used to push the floating slag on the water surface inside the hydrolysis acidification tank 1 toward the slag discharge port 12.

[0046] Anaerobic reactor 3 is provided with an anaerobic inlet 30 for feeding and an exhaust outlet 31 for venting. The anaerobic inlet 30 is connected to the acidification outlet 11 through a transfer pump 6. Anaerobic reactor 3 is used to supply hydrolyzed and acidified kitchen waste for anaerobic treatment.

[0047] In this embodiment, the kitchen waste first enters the hydrolysis and acidification tank 1. Inside this tank, specific microorganisms carry out a hydrolysis and acidification reaction, breaking down large organic molecules into smaller ones. Specifically, the slurry undergoes hydrolysis, acidification, and partial acetylation within the tank. Under the action of hydrolytic and fermentative bacteria (facultative / obligatory anaerobic bacteria), the large organic molecules are decomposed into VFAs (acetic acid, propionic acid, butyric acid, etc.), alcohols, H2, CO2, and other organic compounds. A small amount of CH4 is produced. The scum generated during this process is pushed to the scum discharge port 12 by the scum skimming mechanism 2 and transported to the previous process—the digester—to recover oil and hydrothermally decompose and recover organic matter. After hydrolysis and acidification, the kitchen waste is pumped from the acidification outlet 11 through the anaerobic inlet 30 into the anaerobic reactor 3 via the transfer pump 6. In the anaerobic reactor 3, the kitchen waste continues to undergo subsequent reactions in an anaerobic environment. Since most of the oil and scum that affect microorganisms have been removed in the previous step, small molecule organic matter such as VFA, H2 / CO2 can be efficiently converted into CH4 gas under the action of methanogenic archaea in this tank. The gas generated in this tank is discharged from the exhaust port 31, thereby realizing the process of anaerobic biogas production from kitchen waste.

[0048] As can be seen from the above working process, the advantages of this embodiment are as follows: Firstly, because the hydrolysis acidification tank 1 and the anaerobic reactor 3 are set up separately, the hydrolysis acidification tank 1 is used for the reaction of waste in the three stages of hydrolysis acidification, and the anaerobic reactor 3 is used for the reaction of waste in the anaerobic reaction stage. The hydrolysis acidification stage and the methanogenesis stage are placed in two precisely designed reactors, realizing efficient functional zoning. The hydrolysis acidification tank 1 focuses on the rapid degradation of macromolecular organic matter, and the methanogenesis tank focuses on efficient gas production, avoiding mutual interference. By activating the activity of specific bacterial groups, the biogas production efficiency is effectively improved. Secondly, because the scum skimming mechanism 2 is set in the hydrolysis acidification tank 1, the scum skimming mechanism 2 pushes the scum on the water surface in the hydrolysis acidification tank 1 to the scum discharge port 12, which can remove oil that affects the activity of microorganisms and scum that affects the degradation of organic matter. At the same time, it can reduce the scaling rate of the online device, which can also improve the subsequent biogas production efficiency. Moreover, the discharged oil and scum will be returned to the kitchen waste digester for oil extraction and hydrothermal decomposition of organic matter in the scum, so as to improve the resource recovery rate and economic benefits.

[0049] In one specific embodiment, such as Figure 1 As shown, a feasible structure for the hydrolysis acidification tank 1 is further provided. The acidification inlet 10 is connected to the feed pipe, and the slag outlet 12 is connected to the slag outlet pipe. The slag outlet pipe forms a 45-degree angle. The slag outlet 12 in the hydrolysis acidification tank 1 is 0.8 meters away from the top, so that the difficult-to-degrade oil and slag will not block the outlet and will be discharged smoothly.

[0050] In one specific embodiment, such as Figure 1 As shown, a feasible structure for the anaerobic reactor 3 is further provided, wherein the exhaust port 31 of the anaerobic reactor 3 is connected to the biogas collection pipe.

[0051] In one specific embodiment, such as Figure 1 As shown, a feasible structure for the skimming mechanism 2 is further provided. The skimming mechanism 2 includes a skimming drive, a skimming shaft 20, and a skimming impeller 21. The skimming drive is a rotary motor, which is installed on the top of the hydrolysis acidification tank 1. The skimming shaft 20 is arranged along the height direction of the hydrolysis acidification tank 1. The skimming shaft 20 is connected and fixed to the output shaft of the skimming drive, and the skimming impeller 21 is connected and fixed to the skimming shaft 20. The skimming drive is used to drive the skimming impeller 21 to rotate, so that the scum on the water surface in the hydrolysis acidification tank 1 is pushed toward the scum discharge port 12. In specific implementation, after the skimming drive is started, it drives the skimming shaft 20 to rotate, which in turn causes the skimming impeller 21 to rotate. The horizontal rotation of the impeller on the water surface will sweep the entire water surface horizontally, thereby pushing the scum on the water surface to rotate and gather outward, and finally push it toward the scum discharge port 12. This top-mounted skimming mechanism 2 can push the scum on the water surface to the maximum extent.

[0052] It should be noted that the output speed of the skimming drive in this example is relatively slow in order to avoid breaking up the scum and carrying it into the entire water body, which would cause the sludge to float. Specifically, taking a blade with a length of about 2500-3200mm as an example, the output speed of the skimming drive is 50-100rpm.

[0053] In one embodiment, such as Figure 1 As shown, in order to improve the scum pushing efficiency, the skimming impeller 21 includes multiple blades, all of which are connected and fixed to the skimming shaft 20. The multiple blades are arranged horizontally with the scum discharge port 12, and the blade surfaces are arranged parallel to the axis of the skimming shaft 20, that is, the blade surfaces are arranged perpendicular to the water surface. In specific implementation, the multiple blades arranged vertically form multiple water waves on the water surface in the hydrolysis acidification tank 1. With the thrust of the water waves, the scum can be moved more smoothly along the push of the blades to the scum discharge port 12.

[0054] In one embodiment, to improve the scum discharge rate, the projection size of the rotating surface of the skimming impeller 21 along the height direction of the hydrolysis acidification tank 1 matches the projection size of the hydrolysis acidification tank 1. Specifically, since the projection size of the rotating surface of the skimming impeller 21 matches the projection size of the hydrolysis acidification tank 1, the skimming impeller 21 can cover most of the water surface area inside the hydrolysis acidification tank 1 during rotation. Thus, no matter where the scum is distributed on the water surface, it can be captured by the skimming impeller 21 and pushed towards the scum discharge port 12, thereby effectively improving the scum discharge rate and ensuring the cleanliness of the water surface inside the hydrolysis acidification tank 1 during the methanogenesis stage, providing good environmental conditions for the subsequent methanogenesis reaction.

[0055] In one specific embodiment, another feasible structure for the skimming mechanism 2 is further provided. The skimming mechanism 2 includes a skimming drive, a skimming shaft 20, and a skimming impeller 21. The skimming drive is installed on the side wall of the hydrolysis acidification tank 1 (not shown in the figure). The skimming shaft 20 is arranged along the diameter direction of the hydrolysis acidification tank 1. The skimming shaft 20 is connected and fixed to the output shaft of the skimming drive. The skimming impeller 21 is connected and fixed to the skimming shaft 20. The skimming drive is used to drive the skimming impeller 21 to rotate, so that the floating scum on the water surface in the hydrolysis acidification tank 1 is pushed toward the scum discharge port 12. In specific implementation, after the skimming drive is started, it drives the skimming shaft 20 to rotate, which in turn causes the skimming impeller 21 to rotate. The vertical rotation of the impeller on the water surface will agitate one part of the water surface, thereby pushing the floating scum from the agitated part toward the scum discharge port 12. This side-mounted skimming mechanism 2 can achieve the discharge of floating scum on the water surface without disturbing the fluid at the bottom of the hydrolysis acidification tank 1.

[0056] In one embodiment, the skimming impeller 21 includes multiple blades, all of which are connected and fixed to the skimming shaft 20. The blade surfaces face the slag discharge port 12, and the blade surfaces are arranged perpendicular to the axis of the skimming shaft 20. That is, the blade surfaces are also perpendicular to the water surface. In specific implementation, with the skimming shaft 20 as the center, the water flow stirred by the multiple blades will be pushed from this center to the slag discharge port 12.

[0057] It should be noted that the output speed of the skimming drive in this example is relatively fast, which can disturb the entire water surface at one point as much as possible and push the scum towards the scum discharge port 12. Taking a blade with a length of about 800-1000mm as an example, the output speed of the skimming drive is 200-400rpm.

[0058] As can be seen from the above, the skimming mechanism 2 can be either top-mounted or side-mounted. The advantage of the top-mounted skimming mechanism 2 is that it can directly push as much of the scum on the water surface as possible to the scum discharge port 12, while the advantage of the side-mounted skimming mechanism 2 is that it can reduce the disturbance to the fluid at the bottom of the hydrolysis acidification tank 1. The two different arrangements of the skimming mechanism 2 each have their unique advantages. In practical applications, the appropriate method can be flexibly selected according to the specific situation of the hydrolysis acidification tank 1 and the process requirements. For example, when the hydrolysis acidification tank 1 has high requirements for the stability of the bottom fluid and does not want the bottom fluid to be disturbed... When there is too much interference, those skilled in the art can choose the side-mounted skimming mechanism 2. This setting can ensure that while effectively removing the floating scum on the water surface, the fluid at the bottom remains relatively stable, ensuring the stable operation of the entire anaerobic digester for food waste during the methanogenic stage. When the efficiency of cleaning the floating scum on the water surface is required to be high, and it is desirable to remove the floating scum as quickly and in large quantities as possible, the top-mounted skimming mechanism 2 can better play its advantages. By directly pushing the floating scum to the discharge port 12, it can improve the speed of floating scum cleaning, thereby improving the processing efficiency of the entire methanogenic stage.

[0059] In one specific embodiment, such as Figure 1 As shown, the anaerobic digester for food waste also includes an acid-base adjustment mechanism 4; the acid-base adjustment mechanism 4 is connected to the hydrolysis acidification tank 1, and the acid-base adjustment mechanism 4 is used to adjust the acidity and alkalinity in the hydrolysis acidification tank 1. In specific implementation, the operator can adjust the acidity and alkalinity according to the acidity and alkalinity value in the hydrolysis acidification tank 1 using the acid-base adjustment mechanism 4.

[0060] In this embodiment, the acid-base adjustment mechanism 4 includes an acid-base tester, an acid pump, an acid valve, an alkali pump, an alkali valve, an acid tank, and an alkali tank. The acid-base tester is located inside the hydrolysis acidification tank 1. The acid tank is connected to the hydrolysis acidification tank 1 via the acid pump and the acid valve. The alkali tank is connected to the hydrolysis acidification tank 1 via the alkali pump and the alkali valve. The key is to control the pH of the liquid in the tank within the range of 5.0-6.0 through the pH adjustment device 3, so as to enhance the activity of hydrolytic bacteria and fermentation bacteria, thereby making the hydrolysis and acidification of organic matter more thorough.

[0061] In one specific embodiment, such as Figure 1 As shown, the anaerobic digester for food waste also includes a dosing mechanism 5; the dosing mechanism 5 is connected to the anaerobic reactor 3 and is used to add chemicals into the anaerobic reactor 3. In practice, the operator can add the appropriate chemicals according to the specific reaction conditions in the anaerobic reactor 3 to promote the smooth progress of the methanogenic reaction.

[0062] In this embodiment, the dosing mechanism 5 includes a dosing tank, a dosing pump, and a dosing valve. The dosing tank is connected to the anaerobic reactor 3 via the dosing pump and the dosing valve. In this reactor, pH, VFA, and total alkalinity are monitored. The dosing device controls the pH to 6.8–7.5, VFA to <500-800 mg / L, and total alkalinity to >2000-3000 mg / L, thereby increasing the activity of methanogenic archaea and thus improving the biogas production rate.

[0063] In one specific embodiment, the volume of the hydrolysis acidification tank 1 is smaller than that of the anaerobic reactor 3. In practice, considering the different rates of hydrolysis acidification and methanogenesis, by setting up hydrolysis acidification tank 1 and anaerobic reactor 3 with different volumes, the reaction processes of the hydrolysis acidification stage and the methanogenesis stage can be better matched, making the entire anaerobic biogas production process of food waste more efficient and orderly. The smaller hydrolysis acidification tank 1 can quickly complete the hydrolysis acidification reaction, providing sufficient substrate for the subsequent methanogenesis stage, while the larger anaerobic reactor 3 can provide sufficient reaction space for methanogenic bacteria, ensuring that the methanogenesis reaction proceeds fully, thereby improving the yield and quality of biogas.

[0064] In this embodiment, the volume ratio of the hydrolysis acidification tank 1 to the anaerobic reaction tank 3 is 1 / 2 to 1 / 4. In practice, the operator can flexibly select a suitable tank volume combination within this ratio range according to the actual processing scale and needs. By reasonably setting the volume ratio of the hydrolysis acidification tank 1 to the anaerobic reaction tank 3, the performance of the anaerobic biogas production device for kitchen waste can be optimized to the greatest extent, and biogas can be produced efficiently and stably.

[0065] In summary, this application can be applied to the treatment of wastewater from food factories with high organic content, as well as high molecular weight organic wastewater in other fields, which is conducive to its widespread application.

[0066] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0067] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

[0068] Finally, it should be noted that in this paper, relational terms such as acidification and anaerobic are used only 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.

Claims

1. An anaerobic digester for producing biogas from kitchen waste, characterized in that, include: A hydrolysis acidification tank is used for hydrolyzing and acidifying kitchen waste, and a slag discharge port is provided on the side wall of the hydrolysis acidification tank. A skimming mechanism is provided inside the hydrolysis acidification tank, and the skimming mechanism is used to push the floating scum on the water surface inside the hydrolysis acidification tank toward the scum discharge port; An anaerobic reactor is connected to the hydrolysis acidification tank, and the anaerobic reactor is used to anaerobic treat the hydrolyzed and acidified kitchen waste.

2. The anaerobic digester for food waste production according to claim 1, characterized in that, The skimming mechanism includes a skimming drive, a skimming shaft, and a skimming impeller; The skimming drive is installed on the top of the hydrolysis acidification tank, the skimming shaft is arranged along the height direction of the hydrolysis acidification tank, the skimming shaft is connected and fixed to the output shaft of the skimming drive, and the skimming impeller is connected and fixed to the skimming shaft. The skimming drive is used to drive the skimming impeller to rotate, so that the scum on the water surface in the hydrolysis acidification tank is pushed toward the scum discharge port.

3. The anaerobic digester for food waste production according to claim 2, characterized in that, The skimming impeller includes multiple blades, all of which are connected and fixed to the skimming shaft, and the blade surfaces are arranged parallel to the axis of the skimming shaft.

4. The anaerobic digester for food waste production according to claim 2, characterized in that, Along the height direction of the hydrolysis acidification tank, the projection of the hydrolysis acidification tank is circular, and the projection size of the rotating surface of the skimming impeller matches the projection size of the hydrolysis acidification tank.

5. The anaerobic digester for food waste production according to claim 1, characterized in that, The skimming mechanism includes a skimming drive, a skimming shaft, and a skimming impeller; The skimming drive is installed on the side wall of the hydrolysis acidification tank, the skimming shaft is arranged along the diameter of the hydrolysis acidification tank, the skimming shaft is connected and fixed to the output shaft of the skimming drive, and the skimming impeller is connected and fixed to the skimming shaft. The skimming drive is used to drive the skimming impeller to rotate, so that the scum on the water surface in the hydrolysis acidification tank is pushed toward the scum discharge port.

6. The anaerobic digester for food waste production according to claim 5, characterized in that, The skimming impeller includes multiple blades, all of which are connected and fixed to the skimming shaft, with the blade surfaces facing the slag discharge port.

7. The anaerobic digester for food waste production according to claim 1, characterized in that, The anaerobic digester for food waste also includes an acid-base adjustment mechanism. The acid-base adjustment mechanism is connected to the hydrolysis acidification tank, and the acid-base adjustment mechanism is used to adjust the acidity and alkalinity in the hydrolysis acidification tank.

8. The anaerobic digester for food waste production according to claim 1, characterized in that, The anaerobic digester for food waste also includes a dosing mechanism; The dosing mechanism is connected to the anaerobic reactor and is used to add chemicals into the anaerobic reactor.

9. The anaerobic digester for food waste production according to claim 1, characterized in that, The volume of the hydrolysis acidification tank is smaller than that of the anaerobic reaction tank.

10. The anaerobic digester for food waste production according to claim 9, characterized in that, The volume ratio of the hydrolysis acidification tank to the volume of the anaerobic reaction tank is 1 / 2 to 1 / 4.

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