Wet anaerobic fermentation system

Abstract

The utility model discloses a wet-type anaerobic fermentation system which comprises an anaerobic fermentation tank, a feeding hole is formed in the top of the anaerobic fermentation tank, a discharging hole is formed in the side wall of the anaerobic fermentation tank, and the distance between the discharging hole and the bottom surface of the anaerobic fermentation tank is more than 1m; the feeding hole is arranged close to the stirrer; one end of the feeding hole is sequentially connected with a feeding gate valve and a feeding pump through a pipeline, the other end of the feeding hole is communicated with a feeding pipeline, and the tail end of the feeding pipeline extends below the liquid level of a material area in the anaerobic fermentation tank; the discharge port is communicated with a discharge pipeline, a discharge gate valve is arranged on the discharge pipeline, and when the discharge gate valve is opened, materials in the material area are discharged out of the anaerobic fermentation tank; a stirrer is arranged in the anaerobic fermentation tank, so that light impurities float on the liquid surface, and heavy impurities sink to the bottom of the tank body; the stirrer is a multi-layer paddle type stirrer, each paddle is provided with two paddle surfaces with different curvatures, and the paddle surfaces of each layer of adjacent paddles face opposite directions.

Description

TECHNICAL FIELD

[0001] The utility model relates to a wet anaerobic system, concretely relates to a wet anaerobic fermentation system of processing catering garbage, kitchen garbage. BACKGROUND

[0002] At present, all kinds of anaerobic fermentation processes of processing catering garbage, kitchen garbage are provided with the device of automatically removing dross and removing sand. For the device of removing impurities of anaerobic fermentation tank, short feeding flow field is prone to appear. In addition, the unreasonable selection of discharge position also easily leads to the problem of taking out impurities when discharging.

[0003] In order to make the material entering the fermentation tank to obtain sufficient fermentation time, and not to affect the normal operation of the impurity removal device when discharging, the inlet and outlet pipelines of the anaerobic fermentation tank need to be specially designed. SUMMARY

[0004] The utility model aims at overcoming the deficiency in the prior art, and provides a wet anaerobic fermentation system, which is specially designed for feeding and discharging, so that the material entering the fermentation tank can obtain sufficient fermentation time, and the normal operation of the impurity removal device is not affected when discharging.

[0005] A wet anaerobic fermentation system comprises an anaerobic fermentation tank, and the internal space of the anaerobic fermentation tank is divided into a biogas storage area and a material area from top to bottom.

[0006] A feeding port is formed in the top of the anaerobic fermentation tank, and a discharge port is formed in the side wall of the anaerobic fermentation tank, and the discharge port is more than 1 m away from the bottom surface of the anaerobic fermentation tank; the feeding port is arranged close to the mixer, which is beneficial to the mixing of the material in the material area.

[0007] One end of the feeding port is connected with a feeding gate valve and a feeding pump in sequence through a pipeline, and the other end is connected with a feeding pipeline, and the end of the feeding pipeline is inserted into the material area below the liquid level in the anaerobic fermentation tank.

[0008] The discharge port is connected with a discharge pipeline, and a discharge gate valve is arranged on the discharge pipeline; when the discharge gate valve is opened, the material in the material area is discharged from the anaerobic fermentation tank.

[0009] A mixer is arranged in the anaerobic fermentation tank, so that light impurities float on the liquid surface and heavy impurities sink to the bottom of the tank body; the mixer is a multi-layer paddle type mixer, the paddle has two paddle surfaces with different curvatures, and the paddle surfaces of adjacent layers of paddles face in opposite directions.

[0010] Further, the anaerobic fermentation tank is a cylindrical tank body, and a heat preservation layer is arranged on the outer wall of the tank body.

[0011] Further, the rotation speed of the stirrer is 30-50 rpm, and the rotation speed of the stirrer can be adjusted according to actual needs.

[0012] Further, the anaerobic fermentation tank is further provided with a radar liquid level meter, the liquid level meter is electrically connected with the upper computer, and is used for transmitting the liquid level height of materials in the anaerobic fermentation tank.

[0013] Further, the feeding gate valve and the discharging gate valve are electrically connected with the upper computer, and the upper computer controls the opening / closing of the discharging gate valve according to the height of the radar liquid level meter.

[0014] Further, the anaerobic fermentation system further comprises a scum removal subsystem and a sand removal subsystem, the scum removal subsystem is embedded in the anaerobic fermentation tank, and is used for discharging the scum on the liquid surface of the material area out of the anaerobic fermentation tank; the sand removal subsystem is used for discharging the sand at the bottom of the material area out of the anaerobic fermentation tank, and the feeding port is arranged away from the scum removal subsystem.

[0015] Compared with the prior art, the anaerobic fermentation system has the beneficial effects that:

[0016] The anaerobic fermentation system forms an upper feeding and middle discharging mode, and specifically:

[0017] The feeding port of the anaerobic fermentation system is arranged away from the scum removal subsystem and close to the stirrer, which is beneficial to the paddle material entering the material area to participate in the mixing of the material and avoids the phenomenon of short feeding; the material is pumped into the top of the anaerobic fermentation tank by the feeding pump through the pipeline, the material after fermentation is mixed by the stirrer is gravity flow to the subsequent sewage treatment process section through the pipeline on the side wall of the fermentation tank; the end of the feeding pipeline is below the liquid surface, which can prevent the biogas in the biogas area from flowing back through the feeding pipeline, and is also beneficial to the material being directly pumped into the liquid surface below to be mixed by the stirrer, thereby avoiding the phenomenon that the material floats on the liquid surface and is discharged by the scum removal device.

[0018] The discharging port of the anaerobic fermentation system is more than 1m away from the bottom surface of the anaerobic fermentation tank, considering that there are precipitated impurities and sand at the bottom of the anaerobic fermentation tank, the discharging port is arranged at the middle part of the tank body, so that the discharging port is arranged away from the sand discharge port, thereby avoiding the problem that impurities are brought out during discharging, and thus the normal work of the bottom sand scraping device is avoided, and the normal water discharge is also ensured. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a structural schematic view of the wet anaerobic fermentation system.

[0020] Among them,

[0021] 1: Feed pump; 2: Feed gate valve; 3: Feed pipe; 4: Scum removal device;

[0022] 5: Bottom sand scraper; 6: Mixer; 7: Biogas storage area; 8: Material area;

[0023] 9: Anaerobic fermenter; 10: Discharge pipe; 11: Discharge gate valve. Detailed Implementation

[0024] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. The specific embodiments described are only for explanation and illustration of this utility model and are not intended to limit this utility model.

[0025] like Figure 1 As shown, a wet anaerobic fermentation system includes an anaerobic fermenter 9, a feed channel, a discharge channel, a scum removal subsystem, and a sediment removal subsystem. The anaerobic fermenter 9 is a cylindrical tank with an insulation layer around its outer wall. The space formed by its inner wall is divided from top to bottom into a biogas storage area 7 and a material area 8, with a volume ratio of 1:23. The biogas storage area 7 is used to contain the biogas produced during fermentation, and the material area 8 is used to contain materials and slurry from the feed channel after pretreatment of catering / kitchen waste. The biogas storage area 7 has a biogas collection pipe (not shown in the figure), one end of which is exposed in the biogas storage area 7, and the other end extends out of the anaerobic fermenter 9 and connects to a gas holder.

[0026] The anaerobic fermenter 9 is equipped with a mixer 6, which is a paddle mixer with four propeller blades. Each blade has two surfaces with different curvatures, one with a larger curvature and the other nearly flat. The four blades are arranged in two layers, with the two blades in each layer facing opposite directions. This ensures that when the mixer 6 rotates, the two blades in the same layer generate opposite shear forces and buoyancy, facilitating thorough mixing of the materials. The mixer 6 is installed vertically downwards from the top of the anaerobic fermenter. The rotation speed of the mixer 6 is adjustable as needed. During operation, the mixer runs at a slow speed to promote stratification of the liquid within the anaerobic fermenter. The operation of the mixer 6 ensures thorough mixing of the materials within the anaerobic fermenter 6, accelerating fermentation and allowing light impurities to float to the surface while heavy impurities sink to the bottom.

[0027] The anaerobic fermenter 9 is also equipped with a radar level gauge, which is electrically connected to the host computer and is used to transmit the liquid level height of the material in the anaerobic fermenter 9.

[0028] An inlet is formed on the top of the anaerobic fermentation tank 9, and an outlet is formed on the sidewall of the anaerobic fermentation tank 9, which is more than 1 m away from the bottom of the anaerobic fermentation tank 9, preferably located in the middle of the tank or within the range of 1 m-5 m away from the bottom. In this way, the outlet is far away from the sand discharge outlet, avoiding the problem of bringing impurities out during discharge.

[0029] The feeding channel comprises a feeding pump 1, a feeding gate valve 2, an inlet and a feeding pipeline 3 connected by pipelines. The outlet of the feeding pump 1 is connected to one end of the feeding gate valve 2 by a pipeline, the other end of the feeding gate valve 2 is connected to the feeding pipeline 3, and the feeding pipeline 3 vertically extends into the anaerobic fermentation tank 9 from the inlet and penetrates below the liquid level in the anaerobic fermentation tank (i.e. in the material area 8).

[0030] The discharge channel comprises an outlet and a discharge gate valve 11 connected by pipelines. The outlet is connected to a discharge pipeline 10, and the discharge gate valve 11 is arranged on the discharge pipeline 10. The other end of the discharge gate valve 11 is connected to a treatment unit of the fermented biogas slurry by a pipeline, so that the discharge is discharged from the anaerobic fermentation tank 9.

[0031] The feeding gate valve 2 and the discharge gate valve 11 are both pneumatic knife gate valves, which are controlled by a host computer.

[0032] The host computer controls the opening / closing of the discharge gate valve 11 according to the height of the radar liquid level meter, and controls the opening / closing of the feeding gate valve 2 according to the need.

[0033] The scum removal subsystem comprises a scum removal device 4 and a scum filter. The scum removal device 4 is embedded in the anaerobic fermentation tank 9 and comprises a collection cylinder and a delivery pump. The scum removal device 4 is used to suck out the scum floating on the upper part of the anaerobic fermentation tank 2 and deliver it out of the anaerobic fermentation tank 9. The scum filter is a screw press filter located outside the anaerobic fermentation tank, which separates the collected scum into solid and liquid.

[0034] The sand removal subsystem comprises a bottom sand scraping device 5, a sand pump and a sand-water separator. The bottom sand scraping device is a double-arm type with two circular-arc-shaped scraping arms, the length of which matches the radius of the bottom of the anaerobic fermentation tank. The sand pump sucks out the sand in the sand discharge hole at the bottom of the anaerobic fermentation tank and pumps it to the sand-water separator. The sand-water separator separates the biogas slurry from the sand and solid substances generated in the anaerobic fermentation tank.

[0035] Moreover, in order to avoid the phenomenon of short feeding, the position of the inlet is far away from the scum removal subsystem. Figure 1As shown, the rod of the bottom sand scraping device 5 divides the cross section of the anaerobic fermentation tank 9 into two parts, where the scum removal subsystem is located on one side of the rod of the bottom sand scraping device 5, and the other side of the rod of the bottom sand scraping device 5 is in turn the agitator 6 and the feed pipe 3. This arrangement makes the end of the feed pipe 3 away from the scum removal device 4, avoiding short flow of feed.

[0036] When the anaerobic fermentation system is in use, the specific method is as follows:

[0037] Step one: the feed pump 1 works, the feed gate valve 2 is opened, and the feed pump 1 pumps the pretreated slurry of catering / waste kitchen garbage into the anaerobic fermentation tank 9 through the feed pipe 3;

[0038] Step two: the slurry is fully mixed with the material in the material area 8 by the agitator 6, and biogas is generated;

[0039] Step three: the agitator runs at a speed of 30 rpm to maintain the flow state in the anaerobic fermentation tank 2 and promote the stratification of the slurry in the anaerobic fermentation tank, so that light impurities float on the liquid surface and heavy impurities sink to the bottom of the tank body;

[0040] Step four: the floating scum is removed by the scum removal subsystem; the scum enters the scum removal device 4, the collection cylinder of the scum removal device 4 forms a relatively closed space and collects the scum, and the delivery pump of the scum removal device 4 pumps the collected scum in the cylinder into the scum filter; the agitator 6 supplies the scum removal device 4 with material during the stirring process, continuously sending the scum to the collection cylinder of the scum removal device 4; the scum collected in the collection cylinder of the scum removal device 4 is pumped out of the anaerobic fermentation tank by the delivery pump in the scum removal device 4;

[0041] The settled impurities (such as sand) are removed by the sand removal subsystem.

[0042] Specifically, the bottom sand scraping device 5 collects the sand scattered and deposited at the bottom of the anaerobic fermentation tank 9 and concentrates it at the sand discharge port at the bottom of the anaerobic fermentation tank; the sand pump pumps the concentrated sand out of the anaerobic fermentation tank 9 and into the sand-water separator 9; one scraping arm reaches the sand discharge port, starts the sand pump to suck out the sand, continues to run, the other scraping arm reaches the sand discharge port, starts the sand pump again to suck out the sand, and one cycle of operation is completed; multiple cycles of operation are set according to needs to ensure that the bottom of the anaerobic fermentation tank 9 is not sand-filled. The flow channel and delivery mode of the sand pump can effectively avoid the problems of medium blockage and entanglement during material delivery; the sand pumped by the sand pump is delivered to the sand-water separator through the pipeline. The sand is subjected to solid-liquid separation in the sand-water separator, and the liquid phase returns to the anaerobic fermentation tank for further fermentation.

[0043] Step five: the radar liquid level meter transmits the liquid level height of the material area in the anaerobic fermentation tank 9 in real time, when the liquid level in the tank rises to the first liquid level detected by the radar liquid level meter, the host computer controls to open the discharge gate valve 11, and the digested material in the tank is discharged through the discharge pipeline 10;

[0044] When the liquid level in the tank drops to the second set liquid level, the discharge gate valve 11 is closed.

[0045] Wherein, the first liquid level is higher than the second liquid level, and the first liquid level higher than the second liquid level is the liquid level threshold of the anaerobic fermentation tank 9 preset by the user.

[0046] Although the preferred embodiments of the present application are described above in conjunction with the drawings, the present application is not limited to the specific embodiments described above, and the specific embodiments described above are only illustrative and not restrictive, and those of ordinary skill in the art can make many forms under the inspiration of the present application without departing from the purpose of the present application and the scope protected by the claims, which are all within the protection scope of the present application.

Claims

1. A wet anaerobic fermentation system, characterized by, The anaerobic fermentation tank (9) is provided with an inlet at the top and an outlet on the side wall, which is more than 1m from the bottom of the tank; the inlet is close to the stirrer; One end of the inlet is connected to the inlet gate valve (2) and the inlet pump (1) through a pipeline, and the other end is connected to the inlet pipeline (3), the end of which extends below the liquid level in the material area of the tank; The outlet is connected to the outlet pipeline (10), which is provided with an outlet gate valve (11), which allows the material in the tank (9) to be discharged when opened; The tank (9) is provided with a stirrer (6), which is a multi-layer paddle stirrer with two paddle surfaces with different curvatures, and the paddle surfaces of adjacent layers face in opposite directions.

2. The wet anaerobic fermentation system according to claim 1, characterized in that, The tank (9) is a cylindrical tank with a thermal insulation layer on the outer wall.

3. The wet anaerobic fermentation system according to claim 1, wherein, The speed of the stirrer (6) is 30-50 rpm, and the speed of the stirrer (6) can be adjusted according to actual needs.

4. The wet anaerobic fermentation system according to claim 1, wherein, The tank (9) is also provided with a radar liquid level meter, which is electrically connected to the upper computer and used to transmit the liquid level of the material in the tank (9).

5. The wet anaerobic fermentation system according to claim 4, wherein, The inlet gate valve (2) and the outlet gate valve (11) are electrically connected to the upper computer, which controls the opening / closing of the outlet gate valve (11) according to the height of the radar liquid level meter.

6. The wet anaerobic fermentation system of claim 1, wherein, The anaerobic fermentation system also includes a scum removal subsystem and a sand removal subsystem, the scum removal subsystem is embedded in the anaerobic fermentation tank (9), and is used to remove the scum on the liquid surface of the material area (8) from the anaerobic fermentation tank (9); the sand removal subsystem is used to remove the sand at the bottom of the material area from the anaerobic fermentation tank (9), and the inlet is away from the scum removal subsystem.

7. The wet anaerobic fermentation system of claim 1, wherein, The outlet is 1m to 5m from the bottom of the tank (9).

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