KR100778155B1 - Sludge treatment system - Google Patents

Abstract

An apparatus for anaerobically digesting sewage sludge is provided to improve the efficiency in treatment of organic materials within a digesting tank, by pretreating the sludge through hydrolysis and ultrasonic concentration so that the sludge is suitable for anaerobic digest. A hydrolytic concentration tank(10) concentrates raw sludge by hydrolyzing raw sludge, which is generated from a first precipitating pond, with NaOH. An ultrasonic concentration tank(20) concentrates sludge by applying ultrasonic waves to excess sludge, which is generated from a second precipitating pond, to break cell membranes of microorganisms within the sludge. A heat exchange tank consisting of a first heat exchange tank and a second heat exchange tank draws the concentrated sludge, and maintains the temperature of the concentrated sludge by using waste heat of discharged water, which is discharged from a heat pump and a digesting tank. A first digesting tank(40) injects the heat-exchanged sludge in an upflow type using a donut type nozzle installed below a draft tube, and stirs the injected sludge with a screw type impeller installed within the draft tube. A second digesting tank(50) returns leachate and the microorganisms to the first digesting tank.

Description

Anaerobic Digestion Treatment System by Hydrolysis of Sewage Sludge and Ultrasonic Concentration {Sludge Treatment System}

1 is a schematic representation of the overall processing system of the present invention;

2 is a block diagram of a hydrolysis concentration tank of the present invention,

3 is a configuration diagram of the ultrasonic concentration tank of the present invention,

4 is a heat exchange system configuration diagram by the heat pump of the present invention,

5 is a configuration diagram of a first digester of the present invention,

6 is a detailed view of the screw-type impeller of the present invention,

7 is a detailed view of the sludge dosing device of the present invention,

8 is a detailed view of the scum shredding apparatus of the present invention;

9 is a flow analysis result inside the first digester by the screw-type impeller of the present invention,

10 is a flowchart of the automatic driving system of the present invention.

* Explanation of symbols on the main parts of the drawing

1: fresh sludge drawing pump 2: surplus sludge drawing pump

3: hydrolysis concentration tank drawing pump 4: ultrasonic concentration tank drawing pump

5: sludge supply pump 6: internal circulation pump

7: sludge drawing pump 8: gas storage tank

9: sludge storage tank 10: hydrolysis concentration tank

11: NaOH chemical tank 12: Chemical input pump

13: cylindrical hydrolysis tank 14: + shaped hydrolysis thickening basin

15: hydrolysis sludge outlet 16: hydrolysis concentration tank drive motor

17 hydrolysis concentration tank drive shaft 18 hydrolysis concentration tank scraper

20: ultrasonic concentrator 21: center well inner tube

22: Centerwell outer tube 23: + shaped ultrasonic concentration basin tube

23-1: Hurenji 24: ultrasonic condenser basin pipe outlet

25: Ultrasonic Thickener Picket 26: Ultrasonic Thickener Scraper

27: ultrasonic condenser drive shaft 28: ultrasonic concentrator drive motor

29: sprocket 29-1: non-metallic chain

31 heat pump 32 first heat exchange tank

32-1: temperature sensor 32-2: heat exchange coil

33: expansion valve 34: second heat exchange tank

34-1: heat exchange coil 40: first digester

41: donut type nozzle 41-1: injection hole

42: draft tube 43: screw-type impeller

43-1: screw type impeller drive motor 43-2: drive shaft

43-3: rotation guide cap 44: scum shredding device

45: gas outlet 46-1: number 1 screw blade

46-2: screw No. 2 47: digester temperature sensor

50: second digester 80: aeration tank

111: pH sensor 112: PH indicator

211: ultrasonic oscillator 212: ultrasonic pole

The present invention relates to an anaerobic digestion treatment apparatus by hydrolysis and ultrasonic condensation of sewage sludge,

The purpose is to reduce and stabilize the organic sludge generated in existing sewage and manure wastewater treatment facilities by high efficiency extinguishing and recover methane gas.

In general, a brief review of the known sewage sludge digestion techniques,

Used in sewage sludge treatment in Europe since 1936,

In Japan in the 1950s, volunteers recommended digestion as a recommendation.

In 1956, Japan's Ministry of Health began applying anaerobic treatment to the four-year plan in earnest.

In Korea, anaerobic digestion was attempted to treat manure in 1973, and since 1975, it has been established as one of the methods of manure treatment.

Since the 1980s, the anaerobic digestion system has been adopted as part of the sewage sludge treatment generated in the sewage treatment process of large cities.

However, these conventional techniques do not emphasize the properties of the sludge, and put the fresh sludge and surplus sludge directly into the first digester, and operate in a basic state for pH, temperature, agitation, and activation of methane bacteria in anaerobic digestion. Therefore, due to many problems in the conventional anaerobic digestion method was not actually applied a lot.

The present invention has been studied to improve the problems of the conventional anaerobic digestion treatment of sewage sludge,

An object of the present invention is to improve the extinguishing efficiency of sludge generated in the sewage treatment process, to stabilize the organic material treatment and methane gas production to recycle energy, improve the dewatering rate of sludge, minimize the discharge of sludge, To provide convenience and economy.

To this end, the present invention,

It is divided into raw sludge (primary sediment sludge) and surplus sludge (aerobic microorganism) in the sludge properties. Indirect heating method is adopted to maintain the proper temperature and to stir inside the digester for the manipulation technique and activation of microorganisms.

In consideration of economic feasibility, the heat exchange method by heat pump adopts sludge which is recovered by preheating digester.

The internal agitation of the digestion tank is a method of stirring by screw-type impeller in order to maintain the microorganism, organic matter and temperature as evenly as possible and to form the optimum conditions. It is configured to be automatically put in according to the required temperature, and the sludge input method is put in the upflow by the donut-type nozzle, so that it can be effectively processed for stirring and equalization of temperature and separation of sediment (inorganic matter). by doing,

Reduce the capacity of digester by improving the efficiency of processing organic matter in digester, improve the economic benefits of using waste heat by external heating (indirect), provide convenience of maintenance, and reuse as heat source by production of biogas It is characterized in that to increase and reduce the dewatering efficiency of the final sludge.

Hereinafter, the present invention will be described in detail.

First, the present invention is a hydrolysis concentration tank (10) for sedimentation and separation of NaOH chemical tank (11) and chemical injection pump (12) and hydrolyzed sludge in order to hydrolyze the fresh sludge of the primary sedimentation basin generated in the sewage treatment process. Configure

Fresh sludge entering the primary sedimentation basin has a pH of approximately 6-7. Sometimes it drops to pH 5. Therefore, NaOH is added to the hydrolysis concentration tank 10 to decompose organic matter of fresh sludge, and the PHIC 112 is connected to the heat exchange tank so that the proper pH to be added to the digestion tank is maintained at about 7.8-8.2. To be committed.

The ratio of pH and SCOD / TCOD according to NaOH input per g applied to the hydrolysis concentration tank 10 is shown in Table 1.

Item mg NaOH / g TS time( hr ) 0 6 12 24 pH Blank 6.8 6.2 6.2 6.1 25 7.2 6.9 6.8 6.6 50 8.5 8.1 7.6 7.1 100 9.8 9.6 9.6 9.2 150 12.2 11.5 11.2 11.0 SCOD Of TCOD (%) Blank 3 4 4 4 25 6 7 8 8 50 11 10 11 19 100 20 28 30 40 150 26 34 36 57

 <Table 1> Change of Primary Sludge Liquidity According to NaOH Dose

On the other hand, the excess sludge flowing from the secondary sedimentation basin is mainly a microorganism, the structure of the microorganism is composed of the cell membrane and the cell nucleus, between the cell membrane and the cell nucleus is composed of cell fluid.

The cell fluid contains high concentrations of organic substances, and the cell membrane is composed of elastic celluloid to withstand water pressure.

In addition, the size of microorganisms ranges from several μm to about 1,000μm, and the types are diverse, including circular, spherical, linear, molding, and rod.

Ultrasonic concentrator 20 is configured to contribute to the increase of digestion efficiency and sludge reduction by destroying the cell membrane of the microorganism.

The ultrasonic oscillator 211 uses a direct oscillation method with a frequency of 20 Hz, so that 20,000 contractions and expansions are made in one second, and the pressure generated through the ultrasonic pole 212 in the ultrasonic oscillator 211 is several tens of underwater. It is a technology that destroys cell membranes of microorganisms by contraction and expansion from atmospheric pressure to hundreds of atmospheric pressure.

As a result of experiment on this excess sludge destruction, the stronger the ultrasonic intensity, the better the destruction was.

The lower the flow rate, that is, the longer the irradiation time, the better the destruction. In addition, Table 3 shows the sedimentation efficiency of the ultrasonic irradiated sludge as a result of measuring the sedimentation efficiency according to the presence or absence of ultrasonic irradiation, so that more sludge can be concentrated by ultrasonic irradiation in a concentration tank of the same size.

 <Table 2> Change of SCOD by Ultrasonic Irradiation Intensity and Flow Rate

 <Table 3> Sedimentation Efficiency by Ultrasonic Irradiation

The hydrolysis process and the ultrasonic process provide a pretreatment process to improve the treatment efficiency by dissolving organic material to favor digestion in the digester according to the properties of the sewage sludge, and anaerobic digester is a two-stage digester, generally medium-temperature digestion In the heating method, the indirect heating method was used, and the heating and heat recovery technology was applied to the heat pump 31 which is generally commercially used to provide economic efficiency.

The principle of the heat pump 31 is that when the heat is generated and the heat generated from the sludge at the low temperature (15 ℃) and the first heat exchange tank (32) where the sludge flows, the temperature of the sludge can be increased. As the heat-exchanged gas is lowered in temperature, 35 ° C. desorption liquid discharged from the second digester is introduced into the second heat exchanger 34, and the heat lowered in the first heat exchange tank 32 is absorbed again to heat the heat pump 31. By pressurizing at, the process of generating high heat reduces energy costs by applying the heat supply method by the existing boiler and the cooling and heating method of air in the air conditioner.

The anaerobic digester generally has a medium temperature of 30 ~ 37 ℃, a high temperature of 50 ~ 60 ℃, and the number of days of digestion takes 25 ~ 30 days for medium temperature digestion and 15 ~ 20 days for high temperature digestion. Digestion is mainly adopted. In the present invention, by adopting the medium temperature digestion method, it provides an external circulation method by heat exchange so that the extinguishing temperature can be maintained in the optimum temperature condition 35 ℃ ± 2 ℃ range, the first digestion tank (40) is the temperature condition 35 The first heat exchange tank 32 is supplied with 38 ° C. sludge so that ˜37 ° C. can be maintained.

The essential condition of anaerobic decomposition in the first digester 40 is to maintain a constant temperature, to contact the sufficient microorganisms (methane bacteria) and organic matter (that is, stirring), and to maintain the overall temperature distribution by sufficient agitation to achieve an optimal digester function. Can be.

In order to achieve the optimal digester function, the drift tube 42 is installed inside the digester to install a screw-type impeller 43 inside the drift tube 42 to rotate the impeller, so that the sludge under the drift tube 42 is lowered. It is drawn to the top and discharged on the water line inside the digester, stirring is performed in the digester.

In addition, by dispersing the sludge which is 38 ° C. in the first heat exchange tank 32 by the donut-type nozzle 41 under the drift tube 42, the sludge introduced into the drift tube 42 and the sludge inside the digester are discharged. As the agitation is carried out by the upward flow and the stirring is performed by the screw-type impeller 43, the organic material (VSS) in the first digestion tank 46 is continuously kept, and the optimum temperature and the organic material are maximized by sufficient contact with the microorganism. Can be reduced to 10 days,

As the non-decomposed inorganic matter is collected in the lower portion of the donut-type nozzle 41, the sludge drawing pump 7 is periodically drawn into the sludge storage tank 9, thereby minimizing the amount of sludge drawn out.

The function of the second digester 50 is in the decomposition of untreated organic matter in the first digester 40, the separation of microorganisms and the removal of the desorption liquid.

Temperature condition in the second digester 50 maintains the conditions of 33 ~ 35 ℃ and receives the heat supply from the naturally-treated water of 35 ~ 37 ℃ in the first digester (40) screw type like the first digester (40) After being stirred by the impeller 43 and stopped for a predetermined time and settled and separated, the supernatant water naturally flows into the second heat exchange tank 34 as the releasing liquid, and the sludge settled below is like the lower sludge of the first digester 40. The sludge drawing pump is transferred to the sludge storage tank 9 and subjected to final dewatering treatment.

The main function of the second digester 50 is to obtain the desorption liquid by sedimentation and to decompose the untreated organic matter, so that the residence time is 5 days, the first digester 40, 10 days and the second digester 50, 5 days, for a total of 15 days. By shortening the residence time than the conventional 25 to 30 days, there is an economic advantage that can reduce the digester capacity.

The technical proposal of shortening the number of days of digestion and improving the efficiency is the optimum pH control by hydrolysis of the hydrolysis concentration tank 10 and the dissolution organic materialization of the hardly decomposable organic material, and the microorganisms by the ultrasonic irradiation of the ultrasonic concentration tank 20. By reducing the number of days to extinguish the fire by extinguishing and further improving the technicality of dissolving organic matter suitable for anaerobic digestion, and maintaining the dissolved organic material at an appropriate temperature using waste heat by the heat pump 31 In addition to providing absolute technology for anaerobic digestion, while providing a high-efficiency anaerobic digestion method by stirring the stirring method in the digester in an upstream flow type.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view schematically showing the overall processing system of the present invention,

The fresh sludge generated in the primary sedimentation basin of the sewage treatment plant is supplied to the hydrolysis concentration tank 10 by the fresh sludge drawing pump 1 to adjust pH, hydrolyze and concentrate sedimentation of organic matter, and then, It transfers to the 1st heat exchange tank 32 by (3), and the supernatant water is discharged to the aeration tank 80.

In addition, the excess sludge generated in the secondary sedimentation basin is injected into the lower part of the ultrasonic concentrator 20 by the excess sludge drawing pump 2 and destroyed by the ultrasonic wave irradiated from the ultrasonic oscillator mounted at the upper center, and then the ultrasonic concentrator 20 It is sedimented and separated in the lower part, and is sent to the 1st heat exchange tank 32 by the ultrasonic concentration tank drawing pump 4.

The sludge temperature from the 1st and 2nd sedimentation basin varies depending on the region, but is maintained at about 15 ℃ in the winter and 25 ℃ in the summer. In the first heat exchange tank 32, a heat exchange coil 32-2 capable of heat exchange is installed, and a high-temperature, high-pressure compressed heat (about 110 ° C.) of the heat pump 31 is transferred from the first heat exchange tank 32. By heat dissipation, the heat pump 31 is operated so that the temperature of the inflow sludge (15-25 ° C.) is reached to the 38 ° C. set temperature by heat exchange, and the sludge temperature of the first heat exchange tank 32 is maintained at 38 ° C. .

The desorption liquid of the second digestion tank 50 flows into the second heat exchange tank 34 at a temperature of about 33 to 35 ° C. in the second heat exchange tank 34. In the first heat exchange tank 32, the compressed gas at room temperature and high pressure is vaporized by the expansion valve 33 when introduced into the second heat exchange tank 34. Due to the low temperature and low pressure gas state, the second heat exchange tank 34 absorbs heat by the 33 to 35 ° C desorption liquid flowing from the second digestion tank 50 to supply the heat pump 31 to maximize waste heat. Construct an economic sludge heating plant.

The sludge heated in the first heat exchange tank 40 is sprayed upward from the donut-type nozzle 41 to the lower part of the drift tube 42 installed inside the first digester 40 by the sludge supply pump 5. In the upper part of the drift tube 42, the screw-type impeller 43 is rotated at 600 rpm by the screw-type impeller driving motor 43-1 to achieve complete agitation in the first digester 40.

Since the scum may be formed in the circumferential direction of the upper surface of the water in the first digester 40, the inner circulation pump 6 of the second digester 50 serves to transport the methane bacteria and simultaneously spray the conveying sludge in the circumferential direction. In addition, it is configured to simultaneously perform the role of crushing scum.

The first digester 40 has a space where methane gas can be collected above the water level line so that the gas can be stored in a separate gas storage tank 8 at the top of the digester, and the donut type below the first digester 40 Organic matter is decomposed and the remaining inorganic matters are collected in the lower part of the nozzle 41 and sent to the sludge storage tank 9 by the sludge drawing pump 7 as needed.

Maintaining a water temperature of 35 ~ 37 ℃ for 10 days in the first digester (40) and agitation in the first digester (40) was mixed and treated methane and 38 ℃ sludge in the first heat exchange tank (32) The liquid digested sludge is transferred to the second digester 50 as a natural oil, and the shape of the second digester 50 is the same as that of the first digester 40, but functions differently.

That is, the first digester 40 is mainly intended for the decomposition of organic matter, the second digester 50 is the main purpose for the decomposition of untreated organic matter and recovery and desorption of methane bacteria. Therefore, in order to decompose untreated organic matter, the temperature of 33 ~ 35 ℃ should be maintained and stirring should be done. Therefore, the screw-type impeller 43 of the second digester 50 rotates at 300 rpm and is operated intermittently. The stirring process stops, and after a certain time, the internal circulation pump 6 is operated, and after a certain time, the sludge drawing pump 7 stops after a predetermined time at the bottom of the lower part of the second digester 50, and then the stirrer It acts to recover the desorption liquid and methane bacteria at the stop time, and to continuously process the organic material treatment at the stirring time.

2 is a block diagram of a hydrolysis concentration tank of the present invention,

NaOH is injected into the inlet sludge by the chemical input pump 12 in the NaOH chemical tank 11 for hydrolysis upon sludge inflow by the fresh sludge drawing pump 1 of the primary sedimentation basin.

Hydrolysis is rapidly performed in the cylindrical hydrolysis tank 13 in the center of the hydrolysis thickening tank 10, and sprayed in four directions from the + -shaped hydrolysis thickening basin pipe 14 connected with the hydrolysis tank to discharge the hydrolysis sludge outlet 15. Flows into the concentration tank evenly at the minimum flow rate at. The hydrolyzed thickened sludge is sedimented and separated from the hydrolyzed thickener 10 so that the supernatant is naturally dropped in the aeration tank 80, and the thickened sludge settled under the branch pipe 14 rotates the hydrolyzed thickener driving motor 16. Thus, the hydrolysis concentrating tank scraper 18 is connected to the hydrolysis concentrating tank driving shaft 17 to rotate the hydrolysis concentrating tank scraper 18 at the bottom of the concentrating tank to collect the sludge in the center, and the first heat exchange tank 32 is formed by the hydrolysis concentrating tank drawing pump 3. Sludge is sent to.

Since the pH of the hydrolysis concentration tank 10 supernatant may be greater than 8.2, it may affect the aeration tank 80. Therefore, the pH is detected by the pH sensor 111, and the pH is set to 8.2 by the pH indicator 112 so that the pH is 7.5. The chemical injection pump 12 is automatically injected within the range of ~ 8.2. However, when the raw sludge drawing pump (1) does not operate, do not operate the chemical injection pump (12).

3 is a block diagram of the ultrasonic concentration tank of the present invention,

The surplus sludge of the secondary sedimentation basin is introduced into the ultrasonic concentrator 20 by the surplus sludge drawing pump 2.

In the center of the ultrasonic concentrator 20, a centawell formed of a double cylinder tube is fixed by the concentrator upper bridge, surplus sludge flows into the centawell inner tube 21, and an ultrasonic oscillator at the center upper portion of the inner tube 21. 211 and an ultrasonic pole 212 are irradiated with ultrasonic waves of 20 kHz by the ultrasonic pole 212 to the upstream of the inflow sludge to destroy the cell membranes of microorganisms, and to flow downward by the centawell outer tube 22. The sludge that has been dropped and destroyed in four directions by the + -shaped ultrasonic condenser basin tube 23 is dispersed and flows into the ultrasonic concentrator 20 evenly from the ultrasonic concentrator basin outlet 24. The sludge is sedimented and separated for a certain residence time, and the supernatant is sent to the aeration tank 80, and the sedimented sludge is rotated by the ultrasonic condenser drive shaft 27 by the ultrasonic condenser drive motor 28 installed on the upper side of the ultrasonic condenser 20. Since the sprocket 29 rotates under the ultrasonic condenser drive shaft 27, the non-metal chain 29-1 of the side surface rotates. The nonmetallic chain 29-1 and the ultrasonic concentrator scraper 26 on the bottom are connected to collect the settled sludge in the center.

The collected sludge is sent to the first heat exchange tank 32 by the ultrasonic concentration tank drawing pump 4.

The ultrasonic thickener basin pipe 25, which can connect and support the branch pipe 23 and the scraper 26, is formed at a suitable location of the ultrasonic thickener scraper 26, and the ultrasonic thickener branch pipe 23 is formed of the ultrasonic thickener scraper 26. Let's rotate together. The center well outer tube 22 is fixed, and the ultrasonic condenser basin tube 23 should be rotated, so that the bearing is mounted on the flange 23-1 so as to rotate on the ultrasonic condenser basin tube 23 and rotates smoothly. The structure which can be formed was formed.

4 is a configuration diagram of a heat exchange method using a heat pump of the present invention,

The heat pump is similar to the air conditioning system in general. That is, indoor air is cool by the refrigerant of the air conditioner, and hot air is discharged from the air discharged from the compressor (compressor) installed outdoors. By using this principle in the heat exchange method of the present invention, it is intended to provide the appropriate temperature maintenance, convenience, economics of energy use and ease of maintenance.

In FIG. 4, the heat pump 31 compresses the refrigerant gas to generate heat, thereby causing a high temperature 110 in the heat exchange coils 32-2 arranged at regular intervals to have a maximum heat generating area inside the first heat exchange tank 32. ℃) is aired to transfer heat to the sludge flowing into the tank by the hydrolysis concentrator draw pump (3) and the ultrasonic condenser draw pump (4) to condense the gas in the heat exchange coil (32-2) into gas → liquid In order to maintain the sludge temperature (38 ° C) in the tank at the set temperature, a temperature sensor (32-1) is installed inside the heat exchange tank (32) and connected to a heat pump. It stops, and when it is 36 degrees C or less, it operates by automatic temperature sensing so that a heat pump may operate.

The desorption liquid of the second digestion tank 50 flows into the second heat exchange tank 34 at a temperature of 33 ° C. to 35 ° C., and is the same as the first heat exchange tank 32, but the heat exchange function plays the opposite role. That is, since the heat is released from the first heat exchange tank, the enthalpy inside the heat exchange coil 32-2 is lowered.

At the gas recovery point of the heat exchange coil, the high pressure gas suddenly decreases in pressure due to the expansion valve 33, so that the heat exchange coil 34-1 entering the second heat exchange tank 34 is kept at zero temperature. 2 Enter the heat exchange tank 34. Since the desorption liquid of the second digestion tank 50 is continuously introduced into the second heat exchange tank 34, at least 33 ° C. is maintained at a moment.

Here, the cool refrigerant gas absorbs the heat of the desorption liquid and is supplied to the compressor as a saturated steam at room temperature and low pressure, thereby applying a heat exchange method to the sewage sludge treatment to shorten the operating time of the heat pump 31 by performing heat recovery in the liquid phase. It will provide convenience, sustainability of proper temperature maintenance, economics of energy use and ease of maintenance.

5 is a configuration diagram of a first digester of the present invention,

The sludge heated in the first heat exchange tank 32 is dispersed and introduced upwardly by the donut-type nozzle 41 installed below the first digester 40 by the sludge supply pump 5 and the sludge inside the digester. The mixture is discharged onto the cylindrical draft tube 42 by the rotation of the screw-type impeller 43.

Scum is not formed on the surface near the discharge because the fluctuation and flow rate of the discharge are increased, but scum that is pushed outwards in the digester tank on the surface of the water line having a low flow rate is formed by the water flow. At this time, when the internal circulation pump 6 of the second digestion tank 50 is operated, scum crushing and return of the methane microorganisms of the second digestion tank 50 are performed by the scum crushing device 44.

The screw type impeller 43 is connected to the screw type impeller drive motor 43-1 and the screw type impeller drive shaft 43-2 fixedly installed on the upper part of the digester, and rotates the guide cap 43-3 on the driving shaft water line. When the screw-type impeller drive motor 43-1 is rotated at a speed of about 600 rpm because the screw-type impeller 43 having double wings is fixed to the end of the screw-type impeller drive shaft 43-2, the drift The sludge inside the tube 42 flows up and down inside the digester, and the overall mixing is made. <See Fig. 9>

Complete mixing is one of the absolute factors in improving digester efficiency. In other words, evenly maintaining the internal temperature of the digester by increasing the contact opportunities of organic matter and microorganisms and mixing them completely.

In addition, the remaining solids are deposited on the bottom surface of the digester after organic matter is decomposed. As the lower part of the draft tube 42 is expanded, the flow rate is reduced so that the settled solids are not sucked into the draft tube 42.

The solid matter deposited is drawn together at the time of stopping (stopping) the second digestion tank 50 by the sludge drawing pump 7, and is sent to the sludge storage tank 9 as necessary. At this time, the stirring of the first digester 40 is also suspended.

In addition, a gas discharge port 45 is formed next to the screw-type impeller driving motor 43-1 on the upper part of the first digester 40, and methane gas generated in the digester is stored in the gas storage tank 8 to heat, cook, and generate electricity. It is used in various ways.

6 is a detailed view of the screw-type impeller of the present invention,

Stirring efficiency is increased by the 1st screw vane 46-1 and the 2nd screw vane 46-2 intersecting and fixing to the pipe larger in diameter than the drive shaft 43-2.

Pumping test results by the screw-type impeller 43 is shown in <Table 4>, it can be seen that the flow rate increases linearly with the rotational speed.

RPM Generated differential pressure (Hmm) N ₂ / N ₁ V ₁ (m / sec) Q ₁ (㎥ / min) Q ₂ (㎥ / min) Remarks 510 15 0.864 0.542 0.3927 42.41 530 16 0.898 0.56 0.406 45.52 550 18 0.932 0.594 0.430 50.11 570 20 0.966 0.626 0.453 54.75 590 24 One 0.686 0.497 62.08 610 27 1.034 0.727 0.527 68.09 630 33 1.0678 0.804 0.582 77.74 650 37 1.1017 0.852 0.617 84.93 670 41 1.1356 0.896 0.649 92.15 690 46 1.1695 0.950 0.688 100.53 710 48 1.2034 0.970 0.702 105.66

 <Table 4> Pumping flow rate according to the screw-type impeller rotation

And the flow analysis result by the computer was shown in FIG. 9 by the measurement of the stirring state of the whole digester by the flow velocity, and it can be seen that after 120 minutes of stirring, the inside of the digester is completely stirred.

7 is a detailed view of the sludge dosing apparatus of the present invention,

The injection port 41 is inclinedly mounted inside the upper part of the donut type nozzle 42. As shown in FIG.

8 is a detailed view of the scum shredding apparatus of the present invention,

An internal circulation pump 6 is connected to the scum crusher 44.

10 is a flowchart of the automatic driving system of the present invention;

The fresh sludge is introduced into the hydrolysis concentration tank 10 by the fresh sludge drawing pump 1 in the primary sedimentation basin, NaOH for hydrolysis is controlled by the chemical input pump 11 by measuring the pH. The sludge input into the first heat exchange tank 32 is controlled by a hydrolysis concentration drawer pump 3 operated by a timer.

In addition, the surplus sludge is introduced into the ultrasonic concentration tank 20 by the excess sludge drawing pump (2) in the secondary sedimentation basin, and the sludge input to the first heat exchange tank (32), like the hydrolysis concentration tank (10), is operated by a timer. It is controlled by the ultrasonic concentrator draw pump (4).

The first heat exchange tank 32 is constantly heated and maintained at 38 ° C. by the heat pump 31. Sludge agitation is periodically agitated by a timer, and the sludge input of the first digester 40 is determined according to the temperature measured by the digester temperature sensor 47 in the timer and the first digester.

The sludge input of the second digester 5 is automatically supplied by the natural flow, and the internal circulation pump 6 is automatically operated according to the temperature measured by the timer and the temperature sensor in the second digester 50. The sludge in the digester 50 is conveyed to the first digester 40.

As described above, the present invention is to pre-treat the sludge generated in the sewage treatment process to be suitable for anaerobic digestion by hydrolysis and ultrasonic waves, thereby improving the organic matter treatment efficiency of the digester,

By improving the heating method of the sludge using the heat pump, it provides the maintenance of the proper temperature, convenience and economy,

By providing a new stirring method inside the anaerobic digester, it is possible to increase the efficiency of the digester operation, thereby increasing the efficiency of organic matter treatment, increasing the production of methane gas, and reducing the final dewatered sludge.

Claims (3)

A hydrolysis thickening tank in which NaOH is added to the fresh sludge produced in the primary sedimentation basin, whereby the raw sludge is concentrated by hydrolysis; An ultrasonic concentrator, which irradiates the excess sludge generated in the secondary sedimentation basin to destroy the microbial cell membrane of the sludge and concentrates the sludge; A heat exchange tank which draws the concentrated sludge, recovers the waste heat of the digester effluent discharged from the digester and maintains it at a constant temperature; A first digestion tank for injecting the sludge heat exchanged in the heat exchange tank upwardly with a donut-type nozzle installed under the drift tube and agitating it with a screw-type impeller mounted inside the drift tube; Anaerobic digestion treatment apparatus by hydrolysis and ultrasonic condensation of sewage sludge, characterized in that consisting of a second digester for returning the desorption liquid and microorganisms to the first digester. The hydrothermal and ultrasonic condensation of the sewage sludge according to claim 1, wherein the heat exchange tank comprises a first heat exchange tank of sewage sludge using a heat pump, and a second heat exchange tank by desorption liquid of a second digester. By anaerobic digestion treatment device. The anaerobic digestion treatment apparatus according to claim 1, wherein the first digester comprises a scum crusher for crushing the sludge by the sludge conveyed from the second digester. .

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