CN202226760U - Sludge anaerobic digestion device for enhancing sludge reduction - Google Patents

Abstract

The utility model discloses a sludge anaerobic digestion device for strengthening sludge reduction, which relates to the field of sludge reduction treatment devices. The device mainly comprises a sludge gravity concentration tank, a first-stage sludge anaerobic digestion tank, a second-stage sludge anaerobic digestion tank and a water seal tank, wherein the sludge gravity concentration tank is connected with a sludge inlet of the first-stage sludge anaerobic digestion tank, the first-stage sludge anaerobic digestion tank and the second-stage sludge anaerobic digestion tank are connected through a pipeline by utilizing liquid level difference, the two-stage sludge digestion tank is connected with the water seal tank through an upper overflow mode and a lower overflow mode, and a gas outlet at the top of the two-stage digestion tank is connected with the water seal tank through a pipeline. The stirring effect is improved by respectively arranging the stirrer in the digestion tank, the degradation rate of sludge organic components and the yield of final biogas are improved by controlling the temperature of the primary sludge digestion tank, and compared with a single-stage sludge anaerobic digestion device, the device is more energy-saving, the water content of residual sludge is lower, and the treatment capacity and the treatment cost of subsequent sludge of a sewage treatment plant are greatly reduced.

Description

A sludge anaerobic digestion device for enhanced sludge reduction

technical field

The utility model relates to the field of sludge reduction treatment devices, in particular to a sludge anaerobic digestion device for strengthening sludge reduction.

Background technique

By the end of 2009, the national urban sewage treatment volume reached 28 billion cubic meters, and the production of wet sludge (water content 80%) exceeded 20 million tons. According to the survey results, 80% of the sludge produced by my country's sewage treatment plants has not been properly treated, and the random accumulation of sludge and the pollution and re-pollution problems caused by it have become prominent and have aroused social concern.

In recent years, my country's sludge treatment industry has developed rapidly. Benefiting from the continuous improvement of the production technology of the sludge treatment industry and the continuous expansion of the downstream demand market, the development situation of the sludge treatment industry in the domestic and international markets is very optimistic. During the "Twelfth Five-Year Plan" period, my country's investment in sludge treatment and disposal is expected to reach 60 billion.

Anaerobic digestion of sludge is a biological treatment method that relies on anaerobic microorganisms to decompose organic matter under anaerobic conditions. Suitable for sludge with high organic content.

1 Purpose of sludge anaerobic digestion

(1) Reduce sludge volume

(2) Stabilize the properties of sludge

(3) Improve the dehydration effect of sludge

(4) Utilize the generated methane gas

(5) Eliminate stench

(6) Improve the sanitary quality of sludge

Anaerobic digestion of sludge refers to the process in which the biodegradable organic matter in the sludge is decomposed into carbon dioxide, methane and water by facultative bacteria and anaerobic bacteria under anaerobic conditions, so that the sludge is stabilized. It is one of the commonly used methods for sludge reduction and stabilization.

Sludge anaerobic digestion is a multi-stage complex process. To complete the entire digestion process, it needs to go through three stages, namely hydrolysis, acidification stage, acetic acidification stage, and methanation stage. The stages are both interconnected and influenced each other, and each stage has its own characteristic microbial population.

Generally, the hydrolysis process occurs in the initial stage of sludge anaerobic digestion. The water-insoluble polymer organic matter in the sludge, such as carbohydrates, proteins, fats, cellulose, etc., is hydrolyzed into soluble substances under the action of microbial hydrolytic enzymes. Under the action of facultative bacteria and anaerobic bacteria, the hydrolyzed substances are converted into short-chain fatty acids, such as acetic acid, propionic acid, butyric acid, etc., as well as ethanol and carbon dioxide.

The methanation stage occurs in the later stage of sludge anaerobic digestion. During this process, methanogens convert acetic acid (CH ₃ COOH), H ₂ , and CO ₂ into methane, respectively.

During the entire anaerobic digestion process, the methane produced from acetic acid accounts for about 2/3 of the total, and the methane converted from _CO2 and _H2 accounts for about 1/3 of the total.

Acidogenic bacteria are facultative anaerobic bacteria and obligate anaerobic bacteria, which have strong adaptability to PH, VFA and temperature changes, and fast proliferation; , sensitive to temperature changes, slow proliferation.

In the process of sludge anaerobic digestion, temperature has a significant impact on organic matter load and gas production. Studies have shown that in the process of sludge anaerobic digestion, when the temperature changes by ±3°C, the sludge digestion rate will be inhibited; when the temperature changes by ±5°C, gas production will suddenly stop, causing a large amount of organic acids to accumulate and cause disrupt anaerobic digestion.

In the sludge anaerobic digestion system, various bacteria are only allowed to fluctuate in the neutral vicinity within the appropriate pH range. Microorganisms are very sensitive to changes in pH. The pH range for hydrolysis and fermentation bacteria, hydrogen-producing and acetogenic bacteria is 5.0-6.5, and the pH range for methanogens is 6.6-7.5. If the reaction speed of hydrolytic acidification and acetic acidification process exceeds the speed of methanation process, the pH will decrease, which will affect the living environment of methanogenic bacteria, and then affect the effect of sludge anaerobic digestion. However, due to the buffering effect of the digestive juice, in a certain avoid this from happening.

Utility model content

Aiming at the disadvantages of the existing sludge treatment methods, such as high cost, high energy consumption, and low utilization of resources, the purpose of this utility model is to provide a sludge anaerobic digestion device that strengthens sludge reduction, and further improves the sludge The degradation rate of sludge organic components by sludge anaerobic digestion treatment reduces the cost of sludge treatment and improves the resource utilization rate of waste.

In order to achieve the above object, the technical scheme adopted by the utility model is as follows:

A sludge anaerobic digestion device for strengthening sludge reduction, including a sludge gravity concentration tank, the sludge gravity concentration tank is connected to the sludge inlet of the primary sludge anaerobic digestion tank through pipelines, and the primary sludge anaerobic digestion tank The sludge outlet of the oxygen digestion tank is connected to the inlet end of the secondary sludge anaerobic digestion tank through a pipeline, and the primary sludge anaerobic digestion tank is connected to the heating device through the sludge heat exchange inlet and sludge heat exchange outlet respectively. The two ends are connected, the first-level sludge anaerobic digestion tank is equipped with a first-level mixer, the second-level sludge anaerobic digestion tank is equipped with a second-level mixer, the first-level sludge anaerobic digestion tank and the second-level sludge anaerobic digestion tank They are respectively connected to the water-sealed tank through the biogas flow meter.

Further, in the above-mentioned sludge anaerobic digestion device for enhanced sludge reduction, the sludge gravity concentration tank is equipped with scales and valves.

Further, as mentioned above, a sludge anaerobic digestion device for strengthening sludge reduction, the effective volume of the sludge gravity concentration tank is divided into three equal parts, and the excess liquid discharge valve is arranged above the first section, and the third section There is a supernatant discharge valve above.

Further, in the sludge anaerobic digestion device that strengthens sludge reduction as described above, the first-stage mixer is provided with double-layer blades, the second-stage mixer is a single-layer blade, and both the first-stage mixer and the second-stage mixer are connected to the deceleration machine connection.

Further, in the sludge anaerobic digestion device for enhanced sludge reduction as described above, the horizontal position of the bottom of the sludge gravity concentration tank is higher than the effective liquid level in the first-stage sludge anaerobic digestion tank.

Further, in the sludge anaerobic digestion device for strengthening sludge reduction as described above, both the first-stage sludge anaerobic digestion tank and the second-stage sludge anaerobic tank are equipped with liquid level observation windows, and the bottoms are equipped with There is a vent valve and a vent port.

Further, as described above, a sludge anaerobic digestion device that strengthens sludge reduction, the first-level sludge anaerobic digestion tank and the second-level sludge anaerobic tank are equipped with radar level gauges, safety pressure valves , biogas flow meter, pressure gauge, thermometer and pH meter.

Further, as described above, a sludge anaerobic digestion device for strengthening sludge reduction, the first-stage sludge anaerobic digestion tank is provided with a sampling port, and the second-stage sludge anaerobic digestion tank is provided with Supernatant discharge port, sludge discharge port and standby sludge discharge port.

Still further, in the above-mentioned sludge anaerobic digestion device for enhanced sludge reduction, the pipeline connecting the sludge gravity concentration tank and the first-stage sludge anaerobic digestion tank is provided with a pipeline vent valve.

Furthermore, as mentioned above, a sludge anaerobic digestion device for strengthening sludge reduction, the pipeline connecting the primary sludge anaerobic digestion tank and the secondary sludge anaerobic digestion tank is provided with maintenance valves and Siphon valve.

The beneficial effects of the utility model are:

1) Since the bottom of the sludge gravity concentration tank is higher than the effective water level of the primary sludge concentration tank and has a scale, feeding does not require power equipment or metering equipment, which reduces equipment investment for the water plant;

2) Due to the double-layer stirring effect of the first-stage mixer, it is possible to avoid dead mud and stirring dead angle inside the reactor;

3) The temperature and PH value of the reaction can be well controlled through the heating device and the stirring device, and the sludge can achieve a relatively high proportion of sludge reduction effect, and the organic pollutants, roundworm eggs, bacteria and other harmful substances It can be completely removed; the remaining amount of sludge after anaerobic digestion is about 51% of the original amount of added sludge, and the dehydration performance of this part of sludge has been greatly improved after anaerobic digestion of sludge. If after deep dehydration or incineration, the sludge output will be less;

4) Because the utility model adopts the two-stage sludge anaerobic digestion technology, the reaction will generate biogas, which can be used as an energy source for maintaining the reaction temperature or performing deep dehydration, so the whole process does not require external energy supplementation, and achieves low energy consumption. , saving costs for water plants;

5) Compared with the single-stage sludge anaerobic digestion device, when the total SRT (sludge sludge age) is the same, the single-stage reaction often needs the whole process of heating and stirring, because the utility model enters the second stage in the late stage of the reaction The characteristics of the sludge anaerobic digestion device and the secondary sludge anaerobic digestion device are that it does not require heating and deep stirring, and the separation of mud and water is more complete. As a result, the sludge reduction effect is better, and the energy consumption is more energy-saving and consumption-reducing.

Description of drawings

Fig. 1 is a structural schematic diagram of a sludge anaerobic digestion device for enhanced sludge reduction in the present invention.

Detailed ways

The utility model will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Since there are many components involved in the sludge anaerobic digestion device of the present utility model, first, the names of the components corresponding to the reference numerals in the drawings are explained:

101-sludge gravity concentration tank; 20-1 primary sludge anaerobic digestion tank; 301-secondary sludge anaerobic digestion tank; 401-water seal tank;

1-1-1-Excess liquid discharge valve; 1-1-2-Supernatant liquid discharge valve; 1-2-Pipeline vent valve;

2-1-sludge inlet; 2-4-first-stage mixer; 2-10-heating device; 2-9-1-sludge heat exchange inlet; 2-9-2-sludge heat exchange outlet; 2-14 -Sampling port; 2-16-Sludge outlet; 2-17-Maintenance valve; 2-18-Siphon valve;

3-1-sludge inlet; 3-4-secondary mixer; 3-12-supernatant discharge port; 3-13-standby sludge discharge port; 3-14-sludge discharge port; 3-15-sludge discharge valve;

2-radar level gauge; 3-safety pressure valve; 5-biogas flow meter; 6-pressure gauge; 7-thermometer; 8-PH meter; 9-venting port; 10-venting valve;

Fig. 1 has shown the structural representation of a kind of sludge anaerobic digestion device of the utility model that strengthens sludge reduction, and this device mainly comprises the sludge gravity thickening tank 101 with scale, primary sludge anaerobic digestion tank 201, Secondary sludge anaerobic digestion tank 301 and water seal tank 401. The effective volume of the scaled sludge gravity concentration tank 101 is divided into three equal parts, the excess liquid discharge valve 1-1-1 is installed above the first section, and the supernatant liquid discharge valve 1-1 is installed above the third section -2, the horizontal position of the bottom of the sludge gravity concentration tank 101 is higher than the effective liquid level in the primary sludge anaerobic digestion tank 201, and the bottom pipeline of the sludge gravity concentration tank 101 is equipped with a pipeline vent valve 1-2, The pipeline is connected to the sludge inlet 2-1 of the first-level sludge anaerobic digestion tank 201; the first-level sludge anaerobic digestion tank 201 and the second-level sludge anaerobic digestion tank 301 are connected through pipelines by utilizing the liquid level difference, and the sludge Enter the secondary sludge anaerobic digestion tank 301 through the sludge discharge port 2-16 through the mud inlet end 3-1 of the secondary sludge anaerobic digestion tank, the primary sludge anaerobic digestion tank 201 and the secondary sludge anaerobic digestion tank The oxygen digester 301 enters and exits the sludge through the way of top-down overflow, and the primary sludge anaerobic digestion tank 201 is connected with the sludge heat exchange inlet 2-9-1 and the sludge heat exchange outlet 2-9-2 respectively. Both ends of the heating device 2-10 are connected, and the external circulation and continuous heating of the digestion tank by the heating device can effectively improve the mixing effect of the sludge in the tank. The two sludge anaerobic digestion tanks are metered by the biogas flow meter 5 and then enter the water-sealed tank 401. The biogas generated by the digestion tanks is passed through the water-sealed tank 401 to remove water vapor and solid impurities, and then collected for resource utilization. The first-level sludge anaerobic digestion tank 201 and the second-level sludge anaerobic digestion tank 301 are also equipped with mixers, and the first-level mixer 2-4 of the first-level sludge anaerobic digestion tank 201 is provided with double-layer blades, and the second-level sludge anaerobic digestion tank 301 is equipped with double-layer blades. The secondary mixer 3-4 of the anaerobic digestion tank 301 is a single-layer blade. Stirring the sludge in the digestion tank by the mixer can effectively improve the degradation rate of the organic components of the sludge and the yield of the final biogas during the sludge anaerobic digestion process.

Both the primary sludge anaerobic digestion tank 201 and the secondary sludge anaerobic digestion tank 301 are equipped with a safety pressure valve 3, a biogas flow meter 5, a pressure gauge 6, a thermometer 7 and a pH meter 8, and a radar liquid level is installed on the top 2 for real-time monitoring and adjustment of relevant parameters such as reaction temperature, biogas flow rate and pH value in the two sludge anaerobic digestion tanks. A liquid level observation window 11 is provided above the primary sludge anaerobic digestion tank 201 and the secondary sludge anaerobic digestion tank 301 , and a vent port 9 and a vent valve 10 are provided at the bottom. The primary sludge anaerobic digestion tank 201 is provided with 2 sampling ports 2-14, and the secondary sludge anaerobic digestion tank 301 is provided with 3 supernatant discharge ports 3-12 and sludge discharge port 3 -14. Sludge discharge valve 3-15 and standby sludge discharge port 3-13. Sludge is discharged from the bottom of the digestion tank through overflow from the sludge discharge port 3-14 and sludge discharge valve 3-15.

In addition, the pipeline connecting the sludge gravity concentration tank 101 and the primary sludge anaerobic digestion tank 201 is also equipped with a pipeline vent valve 1-2, and the primary sludge anaerobic digestion tank 201 is connected to the secondary sludge anaerobic digestion tank. The pipeline connected to the tank 301 is provided with a maintenance valve 2-17 and a siphon valve 2-18, so as to facilitate cleaning and maintenance of the connecting pipeline.

The following is a brief introduction to the steps of sludge anaerobic digestion using this device, mainly including the following steps:

Step 1. First, pre-treat the sludge entering the digestion unit, and introduce the remaining sludge produced by the sewage treatment plant into the sludge gravity concentration tank for gravity concentration (the sewage plant with the primary settling tank puts the sludge from the primary settling tank and the secondary settling tank treatment after mixing), the water content of the excess sludge produced by the general sewage treatment plant is 99%, and it is concentrated by gravity 3 times before entering the anaerobic digestion unit. In order to ensure the stability of the anaerobic digestion reaction in the later stage, the water content of the concentrated sludge should be kept at a constant value as much as possible; when the sludge is introduced into the gravity concentration tank, in order to ensure that the introduced sludge is the effective volume of the concentration tank, that is On the scale line of the first section of the gravity concentration tank, keep the excess liquid discharge valve 1-1-1 open, so that the excess sludge can be discharged;

Step 2. After the sludge anaerobic digestion is officially started, the heating device and stirring are turned on at the same time. The external temperature control heating method keeps the internal temperature of the system at 34-36°C, and the stirring device stirs the sludge so that the sludge inside the reaction device is Fully mixed state, control the pH to be between 6.4 and 7.5;

Step 3. Feeding is carried out in the way of draining water first and then feeding mud. The heating and stirring are stopped for draining and mud feeding. In order to increase the time of anaerobic digestion as much as possible, the feeding time is shortened as much as possible. Every day is divided into 3 cycles. Feeding time is less than or equal to 10 minutes;

Step 4, using a biogas flowmeter and a biogas analyzer to monitor and analyze the gas production and gas purity;

Step 5, the residence time of the primary sludge anaerobic digestion tank is 14 to 18 days, and the residence time of the secondary sludge anaerobic digestion tank is 4 to 8 days;

Step 6. Discharge the supernatant and sludge periodically every day to keep the balance of incoming and outgoing materials. The generated gas is metered to remove moisture and impurities for resource utilization.

The technical solution of the utility model is firstly to adjust the moisture content of the sludge generated by the daily operation of the urban sewage treatment plant to about 96%, so as to meet the reaction requirements of the sludge anaerobic digestion device. The moisture content of the excess sludge produced in the daily production of the sewage plant is generally 99%. Introduce the sludge gravity concentration tank of the present utility model, observe the measurement scale, and wait for the sludge layer to settle to one-third of the total volume by natural gravity. The supernatant discharge valve 1-1-2 drains the supernatant, and overflows about 96% of the sludge into the first-level sludge anaerobic digestion device for anaerobic digestion reaction. The temperature of the sludge anaerobic digestion device must be Maintain at 34-36°C. Since the heating method of the first-stage sludge anaerobic digestion tank in the utility model is an external circulation heating device, the biogas generated in the reaction can be used as the energy source of the heating device after gas washing and purification to ensure the efficiency of the entire sludge anaerobic digestion system. normal operation. The utility model adopts the method of first discharging mud and supernatant, and then feeding mud to react. The second-stage sludge anaerobic digestion tank utilizes the waste heat of the first-stage sludge anaerobic digestion tank for sludge stabilization and deep gas production.

Obviously, those skilled in the art can make various changes and modifications to the utility model without departing from the spirit and scope of the utility model. In this way, if these modifications and variations of the utility model fall within the scope of the claims of the utility model and their equivalent technologies, the utility model is also intended to include these modifications and variations.

Claims (10)

1. A sludge anaerobic digestion device for strengthening sludge reduction, comprising a sludge gravity concentration tank (101), a sludge gravity concentration tank (101) and a first-stage sludge anaerobic digestion tank (201) through pipelines The sludge inlet (2-1) is connected, and the sludge outlet (2-16) of the primary sludge anaerobic digestion tank (201) is connected to the mud inlet end of the secondary sludge anaerobic digestion tank (301) through the pipeline (3-1) connection, characterized in that: the primary sludge anaerobic digestion tank (201) is connected to the sludge heat exchange inlet (2-9-1) and the sludge heat exchange outlet (2-9-2) respectively. The two ends of the heating device (2-10) are connected, the primary sludge anaerobic digestion tank (201) is equipped with a primary mixer (2-4), and the secondary sludge anaerobic digestion tank (301) is equipped with a secondary The mixer (3-4), the primary sludge anaerobic digestion tank (201) and the secondary sludge anaerobic digestion tank (301) are respectively connected to the water-sealed tank (401) through a biogas flow meter. 2. A sludge anaerobic digestion device for enhanced sludge reduction as claimed in claim 1, characterized in that: said sludge gravity concentration tank (101) is equipped with scales and valves. 3. A kind of sludge anaerobic digestion device for strengthening sludge reduction as claimed in claim 1 or 2, characterized in that: the effective volume of the sludge gravity concentration tank is divided into three equal parts, and the top of the first section is set There is an excess liquid discharge valve (1-1-1), and a supernatant liquid discharge valve (1-1-2) is arranged above the third section. 4. A kind of sludge anaerobic digestion device for strengthening sludge reduction as claimed in claim 1, characterized in that: the primary mixer (2-4) is provided with double-layer blades, and the secondary mixer (3-4) It is a single-layer blade, and both the primary mixer and the secondary mixer are connected with a reducer. 5. A kind of sludge anaerobic digestion device for strengthening sludge reduction as claimed in claim 1 or 2, characterized in that: the horizontal position of the bottom of the sludge gravity concentration tank (101) is higher than that of the primary sludge The effective liquid level in the anaerobic digestion tank (201). 6. A kind of sludge anaerobic digestion device of strengthening sludge reduction as claimed in claim 1, is characterized in that: described primary sludge anaerobic digestion tank (201) and secondary sludge anaerobic tank ( 301) are provided with a liquid level observation window (11), and the bottom is provided with a vent port (9) and a vent valve (10). 7. A kind of sludge anaerobic digestion device for strengthening sludge reduction as claimed in claim 1 or 6, characterized in that: said primary sludge anaerobic digestion tank (201) and secondary sludge anaerobic digestion tank (201) The tanks (301) are all equipped with a radar liquid level gauge (2), a safety pressure valve (3), a biogas flowmeter (5), a pressure gauge (6), a thermometer (7) and a pH gauge (8). 8. A sludge anaerobic digestion device for strengthening sludge reduction as claimed in claim 7, wherein a sampling port (2-14 ), the secondary sludge anaerobic digestion tank (301) is provided with a supernatant discharge port (3-12), a sludge discharge port (3-14) and a standby sludge discharge port (3-13). 9. A sludge anaerobic digestion device for strengthening sludge reduction as claimed in claim 5, characterized in that: the sludge gravity concentration tank (101) and the first-stage sludge anaerobic digestion tank (201) A pipeline vent valve (1-2) is provided on the connected pipeline. 10. A kind of sludge anaerobic digestion device for strengthening sludge reduction as claimed in claim 7, characterized in that: said primary sludge anaerobic digestion tank (201) and secondary sludge anaerobic digestion tank (301) is provided with maintenance valve (2-17) and siphon valve (2-18) on the pipeline that connects.