A three-phase separation completely mixed anaerobic reactor

Abstract

The present invention discloses a three-phase separation completely mixed anaerobic reactor, which includes a tank body, a vertical stirrer, a floating scum discharge pipe, a biogas pipe, a feed pipe and a sediment discharge pipe. A three-phase separation assembly is annularly arranged at the upper part of the tank body. The three-phase separation assembly includes a first baffle plate and a second baffle plate. An inflow area is arranged between the upper part of the first baffle plate and the second baffle plate. A sedimentation area is arranged between the lower part of the first baffle plate and the inner wall of the tank body. A sludge discharge pipe is installed at the bottom of the sedimentation area. A baffle plate is arranged below the first baffle plate. A first reflux seam is arranged between the bottom end of the first baffle plate and the baffle plate. The top end of the second baffle plate is above the liquid level. An upflow area is arranged between the second baffle plate and the inner wall of the tank body. A second reflux seam is arranged between the bottom end of the second baffle plate and the inner wall of the tank body. A water collecting plate is installed in the upflow area. A water collecting area is arranged between the water collecting plate and the tank body. A drain pipe is arranged in the water collecting area. The present invention can effectively realize the continuous and effective separation of sludge, biogas slurry and biogas.

Description

Technical Field

[0001] The present invention relates to the technical field of biogas production engineering by anaerobic digestion. Specifically, it relates to a three-phase separation completely mixed anaerobic reactor. Background Art

[0002] In 2016, according to the estimates of the Ministry of Agriculture and the Ministry of Housing and Urban-Rural Development of the country, the annual output of livestock and poultry manure in the country was 3.8 billion tons, and the comprehensive utilization rate was less than 60%; the output of urban sludge reached about 35 million tons, and the disposal rate was between 50% and 70%; the output of food waste was 548,000 tons per day; the output of catering waste was about 2.73 million tons per day. With the rapid development of the social economy and the accelerating urbanization process, the scale of the breeding industry and the processing industry in China has been increasing day by day. Kitchen waste, food waste, surplus sludge, food processing waste, etc. have also increased year by year with the increase of the urbanization rate and the increase of the urban population across the country. These biomass-rich wastes are extremely easy to degrade and rot, breed mosquitoes and flies, and release various gaseous and liquid pollutants during the process of natural stacking and manual transfer. They have become an important cause of pollution in urban garbage transfer stations, compression stations and landfills, and are also an important source of pollution in the current urban and surrounding environments. Organic solid wastes such as kitchen waste, surplus sludge, livestock manure, and food processing waste usually have high biodegradability, high moisture content, and high organic matter content. At present, the main treatment methods for organic solid wastes are anaerobic digestion, aerobic composting, direct drying for feed, and microbial treatment technology. Since a large amount of biomass energy is contained therein, effectively utilizing such biomass energy is of great significance for realizing the sustainable development of the environment and the economy. In recent years, the anaerobic digestion process has been more and more widely applied in this field. Anaerobic digestion has the advantages of a relatively high degree of harmlessness, overcoming the influence of "homology", and high availability of the product biogas.

[0003] The existing anaerobic digestion technologies mainly include CSTR, UBF, UASB, EGSB, IC, etc.

[0004] The UBF composite anaerobic reactor has a biological film hanging sludge bed area in the middle and a water distribution fluidization area in the lower part. Anaerobic microorganisms are attached to the surface of sand and soft fillers in the form of biological films, and it has the characteristics of small floor area and being suitable for sewage treatment with a relatively high concentration. However, the fillers are extremely easy to be blocked, which affects the hydraulic flow pattern in the reactor and causes local acidification.

[0005] UASB, EGSB, and IC all adopt a complex water distribution system, a circulation and reflux system, and a three-phase separation system. They have the advantages of high treatment efficiency and high operating load. However, when applied to the treatment of wastewater with a high content of solids and grease, the water distribution system and the three-phase separator are easy to be blocked, and they are relatively sensitive to changes in water quality and load.

[0006] At present, in industrial production, a CSTR reactor (Continuous Stirred Tank Reactor, that is, a continuous stirred reactor system, or a completely mixed anaerobic reactor) is usually used to treat high-solid organic waste slurries. The CSTR reactor completes the fermentation of the liquid material and the production of biogas in a closed tank body. A stirring device is installed in the reactor to keep the fermentation raw materials and microorganisms in a completely mixed state. The feeding method adopts constant-temperature continuous feeding or semi-continuous feeding operation. The newly entered raw materials are quickly mixed with all the fermentation liquid strains in the reactor due to the stirring effect, so that the concentration of the fermentation substrate always remains relatively low. However, the traditional CSTR reactor has a simple structure, and it is difficult to discharge floating slag and sediment. Continuous solid-liquid separation cannot be achieved in the reactor, and the hydraulic retention time (HRT) and sludge retention time (SRT) cannot be effectively separated. There are problems such as low sludge concentration in the reactor, low digestion efficiency and treatment load of the reactor.

[0007] In response to the problems in the related technology, no effective solution has been proposed yet. Summary of the Invention

[0008] In response to the above technical problems in the related technology, the present invention proposes a three-phase separation completely mixed anaerobic reactor, which can solve the above problems.

[0009] To achieve the above technical objectives, the technical solution of the present invention is realized as follows:

[0010] A three-phase separation completely mixed anaerobic reactor includes a tank body. A vertical stirrer, a floating slag discharge pipe and a biogas pipe are provided at the top of the tank body. A feed pipe and a sediment discharge pipe are provided at the bottom of the tank body. A three-phase separation component is annularly provided in the upper part of the tank body. The three-phase separation component includes a first baffle plate and a second baffle plate. An inflow area is formed by surrounding between the upper part of the first baffle plate and the second baffle plate. A precipitation area is formed by surrounding between the lower part of the first baffle plate and the inner wall of the tank body. A sludge discharge pipe is installed at the bottom of the precipitation area. A baffle plate is provided below the first baffle plate. A first return seam is formed by surrounding between the bottom end of the first baffle plate and the baffle plate. The top end of the second baffle plate is above the liquid level. An upflow area is formed by surrounding between the second baffle plate and the inner wall of the tank body. A second return seam is provided between the bottom end of the second baffle plate and the inner wall of the tank body. A water collecting plate is installed in the upflow area. A water collecting area is formed by surrounding between the water collecting plate and the inner wall of the tank body. A drain pipe is provided in the water collecting area.

[0011] Further, a purging pipe is provided in the precipitation area. The purging pipe is located above the sludge discharge pipe, and the purging pipe is connected to a blower.

[0012] Furthermore, a fluid inlet is formed by enclosing between the top end of the first baffle plate and the second baffle plate, and the cross-sectional areas of the fluid inlet, the fluid inlet area, and the upflow area are sequentially increased.

[0013] Furthermore, the gap of the second return seam is smaller than the gap of the fluid inlet.

[0014] Furthermore, the angles between the first baffle plate, the second baffle plate, and the baffle plate and the horizontal plane are 45°-60°, and the projected length of the first baffle plate on the baffle plate is 10 cm-20 cm.

[0015] Furthermore, the top end of the second baffle plate is 30 cm-50 cm above the liquid level.

[0016] Furthermore, valves are connected to the scum discharge pipe, the feed pipe, the sediment discharge pipe, the sludge discharge pipe, and the drain pipe, and a water pump is connected to each of the valves.

[0017] Furthermore, the vertical stirrer includes a driving motor, the output end of the driving motor is connected with an output shaft, two-blade propeller blades are uniformly arranged on the output shaft, and a multi-layer structure is adopted.

[0018] The beneficial effects of the present invention are as follows: through the vertical stirrer, an axial flow turbulent flow state from top to bottom in the central area and from bottom to top in the outer edge area is formed in the tank during stirring, strengthening the mixing effect of the slurry and anaerobic digestion sludge in the tank; through the three-phase separation component, the continuous and effective separation of sludge, biogas slurry, and biogas can be effectively realized, reducing the loss of anaerobic digestion sludge, improving the concentration of activated sludge, anaerobic digestion efficiency, and treatment load in the reactor, and prolonging the sludge retention time (sludge age) by intercepting sludge, which can reduce the discharge amount of excess sludge and the scale of dewatered biogas residues; the structure of the device is simple, which can improve the anaerobic digestion efficiency of wastewater containing high suspended solids and oil pollutants, as well as organic solid waste such as excess sludge, livestock and poultry manure, food waste, kitchen waste, and food processing waste. The treatment load is higher than that of traditional technologies, reducing the loss of anaerobic digestion sludge and lowering the total discharge amount of solid waste, with significant social, environmental, and economic benefits. Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1It is a schematic structural diagram of a three-phase separation completely mixed anaerobic reactor according to an embodiment of the present invention.

[0021] Figure 2 It is a schematic structural diagram of the three-phase separation assembly according to an embodiment of the present invention.

[0022] Figure 3 It is a top view of a three-phase separation completely mixed anaerobic reactor according to an embodiment of the present invention.

[0023] In the figure: 1. Tank body; 2. Vertical stirrer; 3. Three-phase separation assembly; 4. Feed pipe; 5. Drain pipe; 6. Biogas pipe; 7. Sludge discharge pipe; 8. Purge pipe; 9. Scum discharge pipe; 10. Sediment discharge pipe; 301. First baffle; 302. Second baffle; 303. Water collection plate; 304. Baffle; 305. Inflow area; 306. Upflow area; 307. Water collection area; 308. Sedimentation area; 309. Inlet; 310. Second return slit; 311. First return slit; 312. Purge pipe. Specific embodiments

[0024] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present invention.

[0025] Such as Figures 1 - 3As shown in the figure, a three-phase separation completely mixed anaerobic reactor according to an embodiment of the present invention includes a tank body 1. A vertical stirrer 2, a floating scum discharge pipe 9 and a biogas pipe 6 are arranged at the top of the tank body 1. A feed pipe 4 and a sediment discharge pipe 10 are arranged at the bottom of the tank body 1. A three-phase separation component 3 is annularly arranged in the upper part of the tank body 1. The three-phase separation component 3 includes a first baffle plate 301 and a second baffle plate 302. An inflow area 305 is formed by enclosing between the upper part of the first baffle plate 301 and the second baffle plate 302. A precipitation area 308 is formed by enclosing between the lower part of the first baffle plate 301 and the inner wall of the tank body 1. A sludge discharge pipe 7 is installed at the bottom of the precipitation area 308. A baffle plate 304 is arranged below the first baffle plate 301. A first reflux gap 311 is formed by enclosing between the bottom end of the first baffle plate 301 and the baffle plate 304. The top end of the second baffle plate 302 is above the liquid level. An upflow area 306 is formed by enclosing between the second baffle plate 302 and the inner wall of the tank body 1. A second reflux gap 310 is arranged between the bottom end of the second baffle plate 302 and the inner wall of the tank body 1. A water collecting plate 303 is installed in the upflow area 306. A water collecting area 307 is formed by enclosing between the water collecting plate 303 and the inner wall of the tank body 1. A drain pipe 5 is arranged in the water collecting area 307.

[0026] In a specific embodiment of the present invention, a purge pipe 312 is arranged in the precipitation area 308. The purge pipe 312 is above the sludge discharge pipe 7, and the purge pipe 312 is connected to a blower.

[0027] In a specific embodiment of the present invention, an inflow port 309 is formed by enclosing between the top end of the first baffle plate 301 and the second baffle plate 302. The cross-sectional areas of the inflow port 309, the inflow area 305 and the upflow area 306 are sequentially increased.

[0028] In a specific embodiment of the present invention, the gap of the second reflux gap 310 is smaller than the gap of the inflow port 309.

[0029] In a specific embodiment of the present invention, the angles between the first baffle plate 301, the second baffle plate 302 and the baffle plate 304 and the horizontal plane are all 45°-60°, and the projection length of the first baffle plate 301 on the baffle plate 304 is 10 cm-20 cm.

[0030] In a specific embodiment of the present invention, the top end of the second baffle plate 302 is 30 cm-50 cm above the liquid level.

[0031] In a specific embodiment of the present invention, valves are connected to the scum discharge pipe 9, the feed pipe 4, the sediment discharge pipe 10, the sludge discharge pipe 7, and the drain pipe 5, and a water pump is connected to each of the multiple valves.

[0032] In a specific embodiment of the present invention, the vertical stirrer 2 includes a driving motor, the output end of the driving motor is connected to an output shaft, and two-blade propeller blades are uniformly arranged on the output shaft and are arranged in a multi-layer structure.

[0033] In a specific embodiment of the present invention, the anaerobic sludge concentration in the tank body 1 is 30 - 50 g / L;

[0034] In a specific embodiment of the present invention, the intermittent operation cycle of scum discharge and sediment discharge is 10 - 15 d, and the startup duration is 15 - 30 min;

[0035] In a specific embodiment of the present invention, the inflow velocity in the inflow area 305 of the three-phase separation assembly 3 is 2 - 3 m / h, the upward flow velocity in the precipitation area 308 is 0.5 - 1.0 m / h, and the flow velocities in the first return slit 311 and the second return slit 310 are both 0.5 - 0.8 m / h.

[0036] In a specific embodiment of the present invention, the width of the three-phase separation assembly 3 is 0.7 - 1.0 mm, and the height is 2.5 - 3.0 m.

[0037] In order to facilitate the understanding of the above technical solution of the present invention, the above technical solution of the present invention will be described in detail below in terms of specific usage methods.

[0038] During specific use, according to a three-phase separation completely mixed anaerobic reactor of the present invention, the kitchen waste slurry after pretreatment such as crushing, sorting, oil removal, and sand removal is fed into the tank body 1 through the bottom feed pipe 4. Under the agitation of the vertical stirrer 2, a turbulent flow state is formed in the slurry in the tank body 1, and the slurry and the sludge are fully mixed. The vertical stirrer 2 can adopt two-blade propeller blades arranged in a multi-layer structure; the kitchen waste slurry is digested and decomposed by anaerobic microorganisms in an anaerobic environment, and part of it is dissolved in water to form biogas slurry, which overflows into the three-phase separation assembly 3 under the action of the circulating water flow;

[0039] Specifically, the slurry enters the inflow area 305 from the inflow port 309. Since the cross-sectional areas of the inflow port 309, the inflow area 305, and the upflow area 306 are sequentially increased, the inflow velocity and the upflow velocity of the slurry mixture entering the three-phase separation component 3 are gradually reduced. In the upflow area 305, the sludge sedimentation velocity is greater than the upward flow velocity of the water, so that the mud and water are separated. The separated wastewater is discharged from the tank body 1 through the drain pipe 5 in the water collection area 307. The sludge flows back into the tank 1 through the first return slot 311 to continue participating in the anaerobic digestion reaction. The biogas overflows on the liquid surface and is collected through the biogas pipe 6 for unified recycling; further, the gap of the second return slot 310 is smaller than the gap of the inflow port 309, so that the sludge can complete the reflux better. Through the baffle plate 304, the refluxed sludge is not affected by the slurry in the tank; further, the angles between the first baffle plate 301, the second baffle plate 302, and the baffle plate 304 and the horizontal plane are 45°-60°, and the projection length of the first baffle plate 301 on the baffle plate 304 is 10 cm-20 cm, so that the biogas forms an air seal on the baffle plate 304 to prevent the upward liquid flow and gas from entering the three-phase separation component through the first return slot 311; further, a purge pipe 312 is arranged in the sedimentation area 305 of the three-phase separation component 3 and is connected to compressed air. At the same time, the outflow condition of the water collection area 307 is observed for the analysis of the effluent quality, and the purge is regularly started to prevent fouling in the three-phase separation component 3; further, the accumulated scum, grease, foam, sediment and other impurities in the tank can be cleaned through the scum discharge pipe 9 and the sediment discharge pipe 10,

[0040] , and intermittent impact discharge is carried out by using the head static pressure; further, the sludge is regularly discharged to the biogas residue dewatering system through the sludge discharge pipe 7 for dewatering treatment.

[0041] This device treats kitchen waste with high concentration, high grease, and high suspended solids. Its application object has strong pertinence. It can improve the anaerobic digestion efficiency of wastewater containing high suspended solids and grease pollutants, as well as organic solid wastes such as excess sludge, livestock manure, kitchen waste, food processing waste, etc. The treatment load is higher than that of traditional technologies, it can reduce the loss of anaerobic digestion sludge, and reduce the total discharge of solid waste, with significant social, environmental and economic benefits.

[0042] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A three-phase separation completely mixed anaerobic reactor, comprising a tank body (1), characterized in that, At the top of the tank body (1), a vertical agitator (2), a floating scum discharge pipe (9) and a biogas pipe (6) are provided. At the bottom of the tank body (1), a feed pipe (4) and a sediment discharge pipe (10) are provided. A three-phase separation assembly (3) is annularly arranged in the upper part of the tank body (1). The three-phase separation assembly (3) includes a first baffle plate (301) and a second baffle plate (302). An inflow area (305) is formed by surrounding between the upper part of the first baffle plate (301) and the second baffle plate (302). A sedimentation area (308) is formed by surrounding between the lower part of the first baffle plate (301) and the inner wall of the tank body (1). A sludge discharge pipe (7) is installed at the bottom of the sedimentation area (308). A baffle plate (304) is arranged below the first baffle plate (301). A first return seam (311) is formed by surrounding between the bottom end of the first baffle plate (301) and the baffle plate (304). The top end of the second baffle plate (302) is above the liquid level. An upflow area (306) is formed by surrounding between the second baffle plate (302) and the inner wall of the tank body (1). A second return seam (310) is arranged between the bottom end of the second baffle plate (302) and the inner wall of the tank body (1). A water collecting plate (303) is installed in the upflow area (306). A water collecting area (307) is formed by surrounding between the water collecting plate (303) and the inner wall of the tank body (1). A drain pipe (5) is arranged in the water collecting area (307). The top end of the second baffle plate (302) is 30 cm - 50 cm above the liquid level; A purge pipe (312) is arranged in the sedimentation area (308). The purge pipe (312) is above the sludge discharge pipe (7). The purge pipe (312) is connected to a blower; The vertical agitator (2) includes a driving motor. The output end of the driving motor is connected with an output shaft. A plurality of propeller blades are evenly arranged on the output shaft. The propeller blades are located in the middle of the tank body (1). The vertical agitator (2) adopts two-blade propeller blades arranged in a multi-layer structure.

2. The three-phase separation completely mixed anaerobic reactor according to claim 1, wherein An inflow port (309) is formed by surrounding between the top end of the first baffle plate (301) and the second baffle plate (302). The cross-sectional areas of the inflow port (309), the inflow area (305) and the upflow area (306) are sequentially increased; 3. A three-phase separation completely mixed anaerobic reactor according to claim 2, characterized in that, The gap of the second return seam (310) is smaller than the gap of the inflow port (309); 4. A three-phase separation completely mixed anaerobic reactor according to claim 1, characterized in that, The included angles between the first baffle plate (301), the second baffle plate (302) and the baffle plate (304) and the horizontal plane are all 45° - 60°. The projection length of the first baffle plate (301) on the baffle plate (304) is 10 cm - 20 cm; 5. A three-phase separation completely mixed anaerobic reactor according to claim 1, characterized in that The floating scum discharge pipe (9), the feed pipe (4), the sediment discharge pipe (10), the sludge discharge pipe (7) and the drain pipe (5) are all connected with valves. A plurality of the valves are all connected with water pumps.

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