KR101452392B1 - Anaerobic digestion tank - Google Patents

Abstract

The present invention relates to an anaerobic digestion tank. To this end, an anaerobic digestion tank according to the present invention comprises: a body unit equipped with an inlet pipe in which wastewater flows in and an outlet pipe in which a processed digestion remainder is emitted; a mechanical stirring unit equipped in the body unit and stirring the influx of the wastewater by being equipped with at least one impeller; and a pump stirring unit circulating the wastewater which flows in from the upper part to the lower part using a pump. According to the present invention, by providing the anaerobic digestion tank which can operate by mixing a mechanical stirring method and a pump stirring method, operation efficiency can be maximized by combining an advantage of the mechanical stirring method and an advantage of the pump stirring method.

Description

An anaerobic digestion tank {ANAEROBIC DIGESTION TANK}

The present invention relates to an anaerobic digestion tank, and more particularly, to an anaerobic digestion tank for uniformly distributing wastewater concentration in an anaerobic digestion tank by stirring wastewater flowing into an anaerobic digestion tank.

Anaerobic digestion is used to treat liquid and semi-solid wastes, and is mainly a process of treating wastewater or wastes by treating organic wastewater such as food wastes desalination liquid and manure, and recovering biogas such as methane. For this purpose, a tank capable of receiving organic wastewater is required, and this tank is referred to as anaerobic digestion tank.

In the anaerobic digestion tank, organic wastewater is absorbed and converted into biogas through decomposition of various microorganisms. In this process, inorganic sediments such as calcareous material, flour, and fiber accumulate in the anaerobic digestion tank. This inorganic precipitate gradually solidifies and accumulates below the anaerobic digester, which eventually requires dredging of the sediment, which prevents the anaerobic digester from operating normally.

Therefore, the wastewater flowing into the anaerobic digester must be mixed, and the mixing method can be classified into three types.

First, there is a non-dynamic stirring method using the head difference (water head difference) caused by the pressure of the biogas generated in the anaerobic digestion tank. Second, there is a mechanical stirring method in which a stirrer is directly installed in the anaerobic digestion tank, Third, there is a pump agitation method using a pump.

However, since the mixing efficiency is lowered when the anaerobic digestion tank is applied to the anaerobic digestion tank, the anaerobic digestion tank may not operate normally due to the formation of sediment in the anaerobic digestion tank. there is a problem. Further, since the biogas generated by the operation of the anaerobic digestion tank is directly introduced into the anaerobic digestion tank, the maintenance cost is low, but scum is generated on the upper surface of the anaerobic digestion tank due to the surface activated sludge of the hydrophobic substance due to the generated bubbles, A problem may arise in the operation of the digester.

In the mechanical stirring system, a motor provided outside is driven to rotate the impeller therein to mix wastewater. Such a mechanical stirring method is effective because it consumes less power and is capable of treating a high concentration and a large capacity of 100 tons or more per day. However, there is a possibility that heavy materials such as sand are accumulated under the anaerobic digestion tank, There is a problem in this anaerobic digester.

The pump stirring method is a method of circulating and circulating the wastewater introduced by using a pump. Such a pump agitation method has a problem that efficiency is lowered when a large capacity of 100 ton per day or more is processed due to an increase in the cost of operating the anaerobic digestion tank because the agitation efficiency is high but the required power is also high.

Registration No. 10-0988587 (anaerobic digestion tank, registered on October 12, 2010)

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide an anaerobic digester having high efficiency by appropriately mixing wastewater introduced into an anaerobic digestion tank.

In order to achieve the above object, the anaerobic digestion tank of the present invention comprises: a body portion having an inlet pipe through which wastewater flows and a discharge pipe through which exhausted digested filtrate is discharged; A mechanical agitator provided in the body portion and having at least one impeller for stirring the introduced wastewater; And a pump agitation unit for circulating and stirring the wastewater flowing from the upper part to the lower part by using a pump.

At this time, the mechanical stirring unit may include at least one impeller provided in the body portion; A shaft rotatably coupled to an upper end of the body portion, the shaft rotating the at least one impeller; And a motor for rotating the shaft, wherein the one or more impellers are two or more, and one of the two or more impellers is located on the upper surface of the incoming wastewater.

The pump agitating unit may include at least one suction port facing upward or laterally to suck wastewater in the body portion and one or more outlets for discharging wastewater sucked through the suction port into the body portion A circulation pipe provided at the other side; And a pump connected in the middle of the circulation pipe and including a pump for sucking wastewater in the body portion into the suction port, wherein the circulation pipe is connected to the other side for discharging the wastewater sucked from the at least one suction port into the body portion A first discharge circulation tube provided with at least one outlet; A second discharge circulation tube spaced apart from the first discharge circulation tube and having at least one outlet at the other side for discharging the wastewater sucked from the at least one suction port into the body part; And a valve for controlling whether or not the waste water is transferred in the second discharge circulation pipe.

The anaerobic digestion tank may include a gas discharge pipe formed on the body portion and discharging the biogas generated in the body portion; A gas compressor for compressing the biogas discharged through the gas discharge pipe; A gas delivery pipe connected to the circulation pipe for delivering the biogas compressed by the gas compressor to the inside of the circulation tube; And a gas storage tank for storing the biogas discharged through the gas discharge pipe.

The apparatus may further include a controller for controlling operations of the mechanical agitator and the pump agitator, wherein the controller alternately operates the mechanical agitator and the pump agitator. The controller controls the operation times of the mechanical agitator and the pump agitator to be alternately operated so as to have a ratio of a to 1, wherein a is preferably a number of 1 or more and 10 or less.

According to the present invention, it is possible to maximize the operation efficiency of the anaerobic digester by combining the advantages of the mechanical agitation system and the pump agitation system by providing the anaerobic digester capable of operating by mixing the mechanical agitation system and the pump agitation system. .

In addition, the biogas generated in the anaerobic digestion tank is introduced into a circulation pipe for pump agitation, and the biogas is discharged to the wastewater discharged into the anaerobic digestion tank body through the circulation pipe, thereby maximizing the performance of the pump agitation There is an effect.

In addition, mechanical agitation and pump agitation can be alternately operated through the control unit, thereby making it possible to maintain the advantages of the mechanical agitation method with less power consumption and large capacity treatment, while compensating for the disadvantages of the mechanical agitation system by the pump agitation system, It has the effect of lowering the maintenance cost of the digester and increasing the performance.

1 is a cross-sectional view of an anaerobic digester according to an embodiment of the present invention.
2 is a perspective view illustrating an anaerobic digester according to an embodiment of the present invention.
3 is a block diagram illustrating an anaerobic digester according to an embodiment of the present invention.

Preferred embodiments of the present invention will be described more specifically with reference to the accompanying drawings.

1, the anaerobic digester 100 of the present invention includes a body 110, a mechanical agitation unit 120, a pump agitation unit 130, a gas transfer unit 140, and a control unit 150 Which will be described with reference to the drawings shown in Figs. 1 to 3. Fig.

The body 110 is formed in a cylindrical shape, and an inlet pipe 112 through which wastewater flows is formed on one side, and a discharge pipe 114 through which the digested filtrate is discharged on the other side is formed. A gas discharge pipe 142 is formed at an upper end of the body 110 to discharge biogas generated by anaerobic digestion of wastewater in the body 110. In an embodiment of the present invention, the inflow pipe 112 is formed on a lower side of the body 110, and the discharge pipe 114 is formed on the body 110, The digested filtrate treated through anaerobic digestion is discharged to the upper portion of the body portion 110.

And a weir 116 which is connected to the discharge pipe 114 through which the extinguishing filtrate is discharged to the outside and functions to display the flow rate, may be included in the body 110. 1, the partition 118 may be installed on the inner wall of the body 110 and the partition 118 may protrude toward the center of the body 110 . When the mechanical agitator 120 or the pump agitator 130 is operated, turbulence generated by the rotation of the wastewater collides against the partition wall 118 to generate a stronger turbulent flow by the scattering action. do.

The mechanical stirring part 120 is provided inside the body part 110 and is for stirring and rotating the wastewater in the body part 110. The mechanical stirring part 120 includes first to third impellers 122a, 122b and 122c, a shaft 124 And a motor 126. As shown in Fig.

The first to third impellers 122a, 122b, and 122c are configured to rotate in the horizontal direction by the shaft 124, and are disposed so as to be spaced apart from each other. At this time, the first impeller 122a is disposed on the upper surface of the wastewater flowing into the body 110 and rotated, thereby preventing the scum from being generated by the bubbles generated by the anaerobic digestion action of the wastewater It plays a role. Therefore, it is not necessary to provide a dispersing plate or the like installed to prevent scum from occurring, and it is possible to prevent scum from being more actively generated by driving the first impeller 122a.

The second impeller 122b and the third impeller 122c rotate while being locked in the wastewater flowing into the body 110, thereby rotating and stirring the wastewater. Of course, the number of impellers may vary as needed.

The shaft 124 is rotatably coupled to the upper end of the body 110 and functions as a rotary shaft through which the first to third impellers 122a, 122b and 122c can be rotated in the horizontal direction. .

The motor 126 is located outside the upper end of the body 110 and is connected to the shaft 124 and provides power for rotating the shaft 124 under the control of the controller 150.

The pump stirring unit 130 is configured to circulate and stir the wastewater introduced by using the pump 134 and includes a circulation pipe 132 and a pump 134.

The circulation pipe 132 is provided with at least one suction port S1, S2, S3 for sucking the wastewater into one side of the upper side for transferring the upper wastewater in the body 110 to the lower side, D2, and D3 for discharging the wastewater sucked through the inlets S1, S2, and S3 into the body 110 again. The circulation pipe 132 extends outwardly from the inside of the body part 110 and then extends into the body part 110 again. Thus, the wastewater sucked into the intake ports S1, S2, and S3 flows out of the body portion 110, then enters the inside again and is discharged through the discharge ports D1, D2, and D3.

In an embodiment of the present invention, the suction ports S1, S2 and S3 are provided with a first suction port S1 formed upward and second and third suction ports S2 and S3 formed laterally, The second and third suction ports S2 and S3 are separated from the upper and lower portions of the body 110 by the suction force of the body portion 110 110) of the waste water. Further, more suction ports can be provided as needed.

The circulation pipe 132 may be separated from the body 110 by a first discharge circulation pipe 132a and a second discharge circulation pipe 132b.

The first discharge port D1 formed at the end of the first discharge circulation pipe 132a is formed at a lower side surface in the body portion 110 so that the waste water forms a circumferentially rotating turbulent flow in the body portion 110. [ In an embodiment of the present invention, at least one first discharge circulation pipe 132a may be installed, and two first discharge circulation pipes 132a are formed in FIGS. 1 and 2. FIG. When two first circulation circulation pipes 132a are provided, as shown in FIG. 2, each of the first circulation pipe 132a, The first and second discharge ports D1 and D2 formed at the end of the first discharge circulation pipe 132a are preferably spaced apart from each other at a predetermined interval.

Also, it is preferable that the first and second outlets D1 and D2 are formed so as to be bent in an upward direction as shown in Figs. 1 and 2, and are formed to be gradually narrowed. This is advantageous for preventing the precipitation phenomenon from occurring in the lower part of the body part 110 and increasing the discharge speed to form a turbulent flow.

The second discharge circulation pipe 132b extends to the center of the lower portion of the body portion 110 so as to be positioned at the center of the inside of the body portion 110. [ The third discharge port D3 formed in the second discharge circulation pipe 132b may be formed with a third discharge port D3 formed in a downward direction as shown in FIGS. 1 and 2, A plurality of three outlets D3 may be formed.

The second discharge circulation pipe 132b may be provided with a valve 136 for controlling whether the waste water is used or not. The valve 136 is provided in the second discharge circulation pipe 132b because it may be unnecessary depending on the operation conditions of the anaerobic digestion tank 100. The valve 136 is opened to operate the second discharge circulation pipe 132b Is more preferable for turbulent flow formation.

The pump 134 is disposed outside the body 110 and is installed in the middle of the circulation pipe 132 so that the waste water can be sucked into the circulation pipe 132 through the suction ports S1, S2, and S3. The pump 134 is preferably installed in the middle of the circulation pipe 132 before the circulation pipe 132 is separated into the first discharge circulation pipe 132a and the second discharge circulation pipe 132b, S1, S2, S3).

The gas transfer section 140 is for transferring biogas generated by anaerobic digestion in the body 110 and includes a gas discharge pipe 142, a gas compressor 144, a gas transfer pipe 146, 148).

The gas discharge pipe 142 is formed on the body, and the biogas generated in the body 110 is discharged.

The gas compressor 144 compresses the biogas discharged through the gas discharge pipe 142 and sends the compressed biogas to the gas transfer pipe 146.

One end of the gas transfer pipe 146 is connected to the gas compressor 144 and the other end of the gas transfer pipe 146 is connected to the circulation pipe 132. The biogas compressed by the gas compressor 144 is circulated through the gas transfer pipe 146 132, respectively. At this time, the position where the other end of the gas transfer pipe 146 is connected to the circulation pipe 132 is located at the front end of the pump 134, and the wastewater and the compressed biogas are introduced into the pump 134 together, Lt; / RTI > Therefore, the effluent discharged into the first to third outlets D1, D2 and D3 through the circulation pipe 132 is mixed with the biogas and discharged, so that the efficiency of the pump agitation can be increased.

The gas reservoir 148 is connected to the gas discharge pipe 142 and stores the rest of the biogas that is not supplied to the gas compressor 144.

The control unit 150 controls the operation of the mechanical agitation unit 120, the pump agitation unit 130, and the gas transfer unit 140, respectively, as shown in FIG. At this time, it is preferable that the operation of the pump stirrer 130 is controlled simultaneously with the operation of the gas compressor 144 of the gas transferring unit 140, and the pump stirrer 130 may be operated only if necessary.

In an embodiment of the present invention, the control unit 150 drives the mechanical stirring unit 120 and the pump stirring unit 130 alternately for a predetermined period of time without simultaneously driving them. For example, the pump agitation unit 130 may operate the mechanical agitation unit 120 for 20 hours a day without being driven, and then the pump agitation unit 130 may be operated while the operation of the mechanical agitation unit 120 is stopped. For the remaining four hours.

The mechanical stirring method consumes less power required for stirring the anaerobic digestion tank 100, and it can be stably stirred because a large capacity of 100 ton per day or more can be processed, but heavy materials such as sand can be accumulated in the bottom. Therefore, after the mechanical agitation unit 120 is operated for 20 hours, the pump agitation unit 130 is operated for the remaining 4 hours to circulate the accumulated substances in the lower part, thereby preventing occurrence of dead zones in the body part 110 can do.

Further, the control unit 150 can further refine the operation of the mechanical agitation unit 120 and the pump agitation unit 130 alternately. For example, the mechanical agitation part 120 is operated for 10 hours, the pump agitation part 130 is operated for 2 hours, the mechanical agitation part 120 is operated again for 10 hours, and the pump agitation part 130 can be operated. This makes it possible to stably stir the large-capacity anaerobic digestion tank 100, suppress the dead zone in the anaerobic digestion tank 100, and minimize the power required for operation of the anaerobic digestion tank 100.

As described above, the controller 150 can alternately operate the mechanical stirrer 120 and the pump stirrer 130 at a predetermined rate of time, and the operation time of the mechanical stirrer 120 and the operation time of the pump stirrer 130) can be expressed as a: 1. In this case, a is preferably 1 to 10 or less, more preferably 3 to 5.

3, when the mechanical stirring unit 120 is operated, the control unit 150 substantially controls the motor 126 to operate the mechanical stirring unit 120, and the pump stirring unit 130 The pump 134 is operated to operate the pump agitator 130 when operating. The controller 150 controls the gas compressor 144 to operate at the same time as the pump 134 when the pump stirrer 130 and the gas transferring unit 140 are simultaneously operated.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It should be understood that the scope of the present invention is to be understood as the scope of the following claims and their equivalents.

100: anaerobic digester
110: body portion 112: inlet pipe
114: discharge pipe 116: weir
118: partition wall 120: mechanical agitation part
122a: first impeller 122b: second impeller
122c: third impeller 124: shaft
126: motor 130: pump stir part
132: circulation pipe 132a: first discharge circulation pipe
132b: second discharge circulation pipe S1, S2, S3: first to third inlets
D1, D2, D3: First to third outlets
134: Pump 136: Valve
140: gas transfer part 142: gas discharge pipe
144: Gas compressor 146: Gas transfer tube
148: gas storage tank 150:

Claims (8)

A body portion having an inlet pipe through which wastewater flows and a discharge pipe through which the treated digestive filtrate is discharged;
A plurality of impellers disposed inside the body portion, one of which is located on the upper surface of the introduced wastewater and the other of which is spaced apart from the one and the lower portion, a shaft rotatably coupled to the upper end of the body portion, A mechanical agitator for stirring the introduced wastewater, the motor including a motor for rotating the shaft;
At least one suction port facing upward or laterally to suck the wastewater in the body portion is provided on one side and one or more outlets for discharging the wastewater sucked through the suction port into the body portion are connected to a circulation pipe A pump agitator connected to the circulation pipe and including a pump for sucking wastewater from the body into the suction port to circulate and stir the wastewater flowing from the upper part to the lower part;
A gas discharge pipe formed in the upper part of the body part for discharging biogas generated in the body part; a gas compressor for compressing the biogas discharged through the gas discharge pipe; and a gas compressor connected to the circulation pipe, A gas delivery pipe for delivering the compressed biogas to the inside of the circulation tube; and a gas storage tank for storing the biogas discharged through the gas discharge pipe, compressing the biogas generated in the body portion and discharging the biogas, A gas transfer part for mixing the wastewater of the agitating part and
And a control unit for controlling operations of the mechanical stirring unit, the pump stirring unit, and the gas transfer unit,
Wherein the controller controls each of the motor, the pump, and the gas compressor so as to alternately operate the mechanical agitator and the pump agitator, and selectively operates the gas transporter when the pump agitator is operated. delete delete delete The method according to claim 1,
Wherein the circulation tube comprises:
A first discharge circulation tube having one or more outlets at the other side for discharging the wastewater sucked from the at least one suction port into the body part;
A second discharge circulation tube spaced apart from the first discharge circulation tube and having at least one outlet at the other side for discharging the wastewater sucked from the at least one suction port into the body part; And
And a valve for controlling whether or not the wastewater is conveyed in the second discharge circulation pipe. delete delete The method according to claim 1,
Wherein the controller controls the operation time of the mechanical agitator and the pump agitator to be alternately operated so that the operation time of the mechanical agitator and the pump agitator becomes a ratio of a to 1, and a is a number of 1 or more and 10 or less.

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