KR20210026858A - Hybrid Biogas Pretreatment Apparatus - Google Patents

Abstract

The present invention provides a hybrid biogas pretreatment device comprising: an anaerobic digester device which decomposes organic waste to generate biogas and digested sludge; a dehydration device which generates dehydrated sludge by removing moisture from the digested sludge generated in the anaerobic digester device; a sludge drying device which generates dried sludge by drying the dehydrated sludge with hot air; a biogas power generation device which generates electricity and heat by using the biogas generated in the anaerobic digester device as an energy source; and a heat recovery device which supplies the heat generated in the biogas power generation device to the anaerobic digester device and the sludge drying device. The hybrid biogas pretreatment device of the present invention provides advantages of producing electricity and heat by using the biogas generated in the process of treating organic waste as an energy source, supplying the generated electricity as internal power in a system or selling the generated electricity, and reducing the moisture in the sludge discharged from the anaerobic digester device through the heat recovery device by the produced waste heat to utilize the sludge as a biomass energy fuel.

Description

Hybrid Biogas Pretreatment Apparatus}

The present invention relates to a hybrid biogas pretreatment apparatus, and more particularly, to a hybrid biogas pretreatment apparatus including a biogas power generation apparatus, a heat recovery apparatus, an anaerobic digester apparatus, a dehydration apparatus, and a sludge drying apparatus.

The modern society is facing the problem of disposing of large amounts of garbage that occurs with the advanced industrial development. Among them, organic wastes such as food waste, livestock manure, and sewage sludge have been banned from ocean dumping since 2012, and are currently only being treated on land.

Among the methods for treating such organic waste, there is an anaerobic digestion method, which is a biological treatment method. Anaerobic digestion has many advantages over aerobic digestion and is currently widely used for the treatment of organic waste. In particular, the anaerobic digestion method is developing into an eco-friendly resource recycling method that produces fuel and compost from organic waste in addition to the simple decomposition and treatment function of organic waste. The situation is being converted to a biogasification facility using this anaerobic digestion method.

As mentioned above, the role of the anaerobic digester is to reduce the load by decomposing organic matter by microorganisms in an anaerobic state, and to increase the decomposition efficiency by increasing the contact between the organic matter and the activated microorganism through sufficient agitation. Digester agitation method includes a variety of methods such as gas agitation using the generated biogas, mechanical agitation, agitation by pump circulation.

There are a method of using extinguishing gas, a method of using a pump, and a method of using a mechanical stirrer for agitation of a digester, and a method of using a simple structure is widely used. The method of using the digestion gas is to supply the biogas into the digester using a high-pressure blower, and mix organic matter by using a disturbance phenomenon that occurs while the biogas floats the sludge layer in the digester.

However, in this method, the mixing of organic matter in the digester is incomplete, and there is a dead zone in which more than 60% of the digester in the digester cannot be stirred, so the efficiency is lowered, and the construction is underway to improve this by mechanical agitation or the like.

In recent years, most of the methods have been converted from a method using a extinguishing gas to a method using a mechanical stirring device. The capacity per digester of domestic sewage and wastewater treatment plants (10,000 tons/day) is 1,500 to 3,000 ㎥ and is operated with a minimum of 2% of total solids and a maximum of 5% of total solids. If the capacity of the digester is 3,000㎥, the diameter of the digester is usually about 20M, and the height of the digester is about 18M or more, so it is necessary to maintain the condition of the sludge stored inside the digester and the conditions for decomposing the sludge in order to produce highly efficient biogas. There is.

In order to solve the above-described problem, in KR Patent Application No. 10-2016-0120024 (name of the invention: organic waste treatment device using a high-efficiency anaerobic digester), organic wastes react several times in the order of reaction → sedimentation → discharge in the digester. While being repeated, there is disclosed an organic waste treatment apparatus in which biogas is generated with high efficiency by digestion by anaerobic microorganisms.

However, in the case of the above-described organic waste treatment apparatus, there is a problem that a separate sludge treatment facility is required to treat the discharged sludge and a problem that requires separate cost and energy for operating the sludge treatment facility.

Throughout this specification, a number of papers and patent documents are referenced and citations are indicated. The disclosure contents of the cited papers and patent documents are incorporated by reference in this specification as a whole, and the level of the technical field to which the present invention belongs and the contents of the present invention are more clearly described.

The inventors of the present invention have made intensive research efforts to develop a hybrid biogas pretreatment device capable of independently batch-processing organic wastes without external energy supply. As a result, of the sludge and biogas generated by the anaerobic digester, biogas uses a biogas generator to produce thermal energy and electric energy, and the produced thermal energy and electric energy uses a heat recovery device, etc., to produce an anaerobic digester and sludge. The present invention was completed by discovering that when used in a drying apparatus or the like, organic waste can be independently processed in a batch without external energy supply.

Accordingly, an object of the present invention is to provide a hybrid biogas pretreatment apparatus.

Other objects and advantages of the present invention will become more apparent by the following detailed description, claims and drawings.

The present invention provides a hybrid biogas pretreatment apparatus.

The inventors of the present invention have made intensive research efforts to develop a hybrid biogas pretreatment device capable of independently batch-processing organic wastes without external energy supply. As a result, of the sludge and biogas generated by the anaerobic digester, biogas uses a biogas generator to produce thermal energy and electric energy, and the produced thermal energy and electric energy uses a heat recovery device, etc., to produce an anaerobic digester and sludge. It was confirmed that when used in drying equipment, etc., organic waste can be independently processed in batches without external energy supply.

According to an aspect of the present invention, the present invention provides an anaerobic digester device for decomposing organic waste to generate biogas and digested sludge, a dewatering device for generating dehydrated sludge by removing moisture from digested sludge generated in the anaerobic digester device, A sludge drying device that generates dry sludge by hot air drying the dehydrated sludge, a biogas power generation device that generates electricity and heat by using the biogas generated in the anaerobic digester device as an energy source, and the biogas power generation device. It provides a hybrid biogas pretreatment apparatus including a heat recovery apparatus for supplying heat to the anaerobic digester apparatus and the sludge drying apparatus.

The term "sludge" as used herein may mean sediment generated during wastewater treatment or water purification.

The term “digestion tank” as used herein may mean a structure in which an agitator, a sludge injector, a gas discharge pipe, etc. are installed inside a tank structure made in a sealed manner to obtain fuel gas and the like at the same time as wastewater treatment.

The term “biogas” used herein may mean any gas generated by fermentation or decay of a medium containing organic matter.

The term “anaerobic bacteria” as used herein may mean bacteria that do not require oxygen in the air.

According to a preferred aspect of the present invention, the dehydration apparatus of the present invention preferably comprises a pretreatment tank for treating the digested sludge with a basic component, a neutralization coagulation tank for treating the digested sludge with an acid component, and the digested sludge treated with a base and an acid. It may include a dehydrator for dehydration.

In the present invention, it is very important to include a pretreatment tank for treating digested sludge with a basic component and a neutralization coagulation tank for treating with an acid component. This is because when the digested sludge is subjected to the basic component treatment through the pretreatment tank and the acid component treatment step through the neutralization coagulation tank, and then the dehydration step is performed, the dehydration step is performed without proceeding the pretreatment tank and the neutralization coagulation tank step. This is because the water content in dewatered sludge can be drastically reduced compared to.

According to a preferred aspect of the present invention, the dehydrator of the present invention may preferably be a filter press dehydrator.

According to a preferred aspect of the present invention, the sludge drying apparatus of the present invention may preferably include a sludge dryer, an air preheater, an auxiliary burner, and an odor removal equipment.

According to a preferred aspect of the present invention, the sludge drying apparatus of the present invention is preferably a sludge dryer for drying the dewatered sludge discharged from the dewatering apparatus, an air preheater and an auxiliary for receiving a heat source required from the sludge drying apparatus. It may include a burner and an odor removal facility for reducing the odor of the dry air discharged after reducing the moisture of the dehydrated sludge.

According to a preferred aspect of the present invention, the sludge drying apparatus of the present invention may preferably include an upper mixer, a lower mixer, or a mixer including an upper mixer and a lower mixer.

According to a preferred embodiment of the present invention, the upper mixer of the present invention preferably pulverizes the introduced dewatered sludge and secures air permeability, and the lower mixer preferably pulverizes the dewatered sludge and prevents bridging.

According to a preferred aspect of the present invention, the dried sludge of the present invention may be preferably generated by a heat source recovered from the biogas generator and a heat source generated from the air preheater and auxiliary burner.

According to a preferred aspect of the present invention, the biogas generator of the present invention may preferably include a gas pretreatment facility, an engine generator, and an exhaust gas heat exchanger for recovering heat of exhaust gas generated after combustion of the biogas.

In the present invention, it is a very important configuration to use the biogas generated in the anaerobic digester as an energy source of the biogas power generation device. This is because, since the organic waste treatment system is operated using the heat source and electricity generated through the biogas generator, the cost required for the system operation can be significantly reduced.

According to a preferred aspect of the present invention, the gas pretreatment facility of the present invention is preferably a dehumidifier and a dehumidifying cooler for removing moisture contained in the biogas, and the cooled biogas using the cooling heat of the auxiliary heat source cooling device. It may include a heat exchanger for raising the temperature, a siloxane removal device for removing siloxane contained in the biogas, a gas booster for increasing the pressure of the biogas, a flow meter, and a gas filter.

According to a preferred aspect of the present invention, the engine generator of the present invention is preferably a generator body that generates electricity by burning biogas, and jacket cooling for recovering internal heat generated during biogas combustion and cooling heat of an auxiliary jacket. It may include an apparatus and an auxiliary heat source cooling device, and an exhaust gas heat exchanger for recovering the exhaust gas heat source.

According to a preferred aspect of the present invention, the heat recovered from the jacket cooling device and the exhaust gas heat exchanger of the engine generator of the present invention is preferably transferred to a heat source required for heating the anaerobic digester device and the sludge drying device through the heat recovery device. It can be supplied with the necessary heat source.

According to a preferred aspect of the present invention, the heat recovery device of the present invention preferably recovers the waste heat generated from the biogas power generation device to heat the anaerobic digester device, and the heating of the anaerobic digester device is If not required, it may include a three-way valve that changes to directly supply a heat source to the sludge drying device.

According to a preferred aspect of the present invention, the heat recovery device of the present invention may further include a second heat exchanger capable of supplementing the heat source of the sludge drying device.

Including a heat recovery device in the present invention is a very important configuration. This is because the cost required for maintaining the system can be minimized by using the heat source generated in the process of driving the biogas power generator in the anaerobic digester system and the sludge drying device requiring a separate heat source.

The features and advantages of the present invention are summarized as follows:

(a) The present invention provides an anaerobic digester device for decomposing organic waste to generate biogas and digested sludge, a dewatering device for generating dehydrated sludge by removing moisture from the digested sludge generated in the anaerobic digester device, and hot air for the dehydrated sludge. A sludge drying device that generates dry sludge by drying, a biogas power generation device that generates electricity and heat by using the biogas generated in the anaerobic digester device as an energy source, and the anaerobic digestion tank with the heat generated by the biogas power generation device. It provides a hybrid biogas pretreatment apparatus including an apparatus and a heat recovery apparatus supplied to the sludge drying apparatus.

(b) The hybrid biogas pretreatment apparatus of the present invention uses biogas generated in the process of treating organic waste as an energy source to produce electricity and heat, and the generated electricity is supplied with power or sold inside the system, and the produced waste heat is The heat recovery device reduces the moisture in the sludge discharged from the anaerobic digester system, thereby providing the advantage that it can be used as a biomass energy fuel.

1 shows a conceptual diagram of a hybrid biogas pretreatment apparatus.
2 shows a conceptual diagram of an anaerobic digester system included in a hybrid biogas pretreatment device.
3 shows a conceptual diagram of a dehydration device included in a hybrid biogas pretreatment device.
4 shows a conceptual diagram of a sludge drying apparatus included in a hybrid biogas pretreatment apparatus.
5 shows a conceptual diagram of a biogas power generation device included in a hybrid biogas pretreatment device.
6 shows a conceptual diagram of a heat recovery device included in a hybrid biogas pretreatment device.
7 shows a cross-sectional view of an anaerobic digester.
8 shows the appearance of the dehydration device included in the hybrid biogas pretreatment device.
9 shows the appearance of the sludge drying apparatus included in the hybrid biogas pretreatment apparatus.

In the present invention, various transformations may be applied and various embodiments may be provided, and specific embodiments will be illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to a specific embodiment, it should be understood to include all conversions, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the present invention, when it is determined that a detailed description of a related known technology may obscure the subject matter of the present invention, a detailed description thereof will be omitted.

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

1 to 6 are conceptual diagrams of a hybrid biogas pretreatment device according to an embodiment of the present invention, an anaerobic digester device included in the hybrid biogas pretreatment device, a dehydration device, a sludge drying device, a biogas power generation device, and a heat recovery device. Is shown, and FIG. 7 is a cross-sectional view of an anaerobic digester apparatus included in the hybrid biogas pretreatment apparatus according to an embodiment of the present invention.

Referring to FIG. 1, a hybrid biogas pretreatment apparatus according to an embodiment of the present invention includes an anaerobic digester apparatus, a dehydration apparatus, a sludge drying apparatus, a biogas power generation apparatus, and a heat recovery apparatus.

Referring to FIG. 2, the anaerobic digester apparatus according to an embodiment of the present invention includes an anaerobic digester, a sludge homogenization apparatus, and a sludge filtration apparatus.

The anaerobic digestion tank stores sludge therein, and agitates the stored sludge using a rotating shaft to which microorganisms and a plurality of impellers are attached, thereby increasing the contact efficiency between microorganisms and sludge, thereby increasing the ability to decompose organic matter.

The sludge homogenization device sucks the input organic sludge, pulverizes the organic matter, and then re-introduces it into the digester.

The sludge filtration device filters organic matter decomposed by microorganisms in the digester to increase the concentration of the organic matter in the digester, and returns the filtered water from which the solids have been removed to the water treatment system to reduce the load on the backwash water.

The sludge homogenization apparatus according to an embodiment of the present invention includes a crushing pump, an input valve 1, an input valve 2, an input valve 3, a nozzle 1 coupled to the input valve 1, and a nozzle 2 coupled to the input valve 2.

The organic sludge in the anaerobic digestion tank is sucked and the coarse organic material is pulverized into small particles through the crushing pump, and then recycled by the input valve 1 and nozzle 1 to the digester, thereby homogenizing the organic sludge inside the digester and using the sludge circulation flow. Prevents settling on the bottom of the tank.

In addition, the input valve 2 and the input valve 3 mix the circulating sludge and the generated biogas and re-inject it into the digester through the nozzle 2 in a pressurized state, thereby generating a vertical mixing force together with a horizontal mixing force, which is generated on the water surface inside the digester. Prevent scum generation.

The input valve 1, the input valve 2, and the input valve 3 are variably adjusted according to the type of organic sludge to be introduced, and may be finely adjusted to homogenize the sludge inside the digester and prevent scum formation.

The sludge filtering apparatus according to an embodiment of the present invention includes a supply pump, a sludge filter, an air compressor, a washing tank, and a washing water pump.

The sludge decomposed inside the digester is sucked and passed through the rotary separation membrane of the sludge filter with the high-pressure sludge through the supply pump, so that the filtered water is treated in conjunction with the sewage treatment plant or wastewater treatment plant, and the filtered sludge is recycled to the digester. Increase the concentration of microorganisms.

The rotary separator is a device for separating sludge deposited on the membrane membrane and discharging the filtered water by using a centrifugal force generated by rotating a micro-sized membrane membrane.

The air compressor, the washing tank, and the washing water pump are washing devices for removing contaminants attached to the rotary separator.

Referring to FIG. 3, the dehydration apparatus according to an embodiment of the present invention includes a pretreatment tank for treating digested sludge with a base component, a neutralization coagulation tank for treating digested sludge with an acid component, and dewatering digested sludge treated with a base and an acid. It includes a filter press dehydrator for.

4, the sludge drying apparatus according to an embodiment of the present invention includes a sludge dryer for drying the dewatered sludge discharged from the dewatering apparatus, an air preheater and an auxiliary burner for receiving a heat source required from the sludge drying apparatus. And a odor removal facility for reducing the odor of the dry air discharged after reducing the moisture in the dehydrated sludge.

The sludge drying device is a device for producing dried sludge and recycling it as fuel by reducing moisture in dewatered sludge discharged from the sludge dewatering device.

In addition, after the moisture of the dehydrated sludge is reduced in the sludge dryer, the odorous dry air discharged is discharged after passing through the odor removal facility.

As a heat source necessary for moisture reduction, a heat source recovered from the biogas generator is used to reduce part of the moisture in the dehydrated sludge.In order to reduce the final target moisture, external air is heated by an auxiliary burner and dried air is heated. After production, it is supplied to a dryer to produce dried sludge.

Referring to FIG. 5, a biogas generator according to an embodiment of the present invention includes a gas pretreatment facility, an engine generator, and an exhaust gas heat exchanger for recovering heat of exhaust gas generated after combustion of the biogas.

The biogas generator is a device that generates power by purifying and utilizing the biogas generated in the anaerobic digester as fuel.The waste heat generated along with the power is recovered through a heat source recovery device and is the heat source of the anaerobic digester and sludge drying device. Use it as.

The gas pretreatment facility includes a dehumidifier and a dehumidifying cooler for removing moisture contained in the biogas, a heat exchanger for raising the temperature of the cooled biogas by utilizing the cooling heat of an auxiliary heat source cooling device, and a siloxane contained in the biogas. It includes a siloxane removal device to be removed, a gas booster for increasing the pressure of the biogas, a flow meter, and a gas filter.

The engine generator is a generator body that generates electricity by burning biogas, jacket cooling device and auxiliary heat source cooling device for recovering internal heat generated during biogas combustion and cooling heat of auxiliary jacket, exhaust gas for recovering exhaust gas heat source. Includes a heat exchanger.

The heat recovered from the jacket cooling device and the exhaust gas heat exchanger of the engine generator is supplied to a heat source required for heating the anaerobic digester device and a heat source required for the sludge drying device through the heat recovery device.

6, the heat recovery device according to an embodiment of the present invention requires a first heat exchanger for recovering waste heat generated from the biogas generator to warm the anaerobic digester, and the anaerobic digester device needs to be heated. If there is no, it includes a three-way valve that changes to directly supply the heat source to the sludge drying device.

The heat recovery device further includes a second heat exchanger capable of supplementing the heat source of the sludge drying device.

The high-temperature water generated in the biogas generator is converted to low-temperature water through the first heat exchanger, the sludge drying device, and the second heat exchanger, and is then resupplied to the biogas generator, thereby being used as cooling water to cool the engine of the biogas generator. .

Referring to FIG. 7, the anaerobic digester included in the high-efficiency anaerobic digester system according to an embodiment of the present invention includes a rotating pipe 40, an impeller 50, a support plate 60, and a driving unit 70.

The rotation pipe 40 serves to rotate the impeller 50 to be described later coupled to the rotation pipe 40.

One or more impellers 50 installed in the rotary pipe 40 to stir and efficiently digest the sludge inside the anaerobic digester are installed, but the size of the digester, the rotational power of the motor, and the impeller 50 for efficient agitation The directions, sizes, and angles of the stirring blades installed in can be installed in various ways.

The impeller 50 is installed with three upper and lower impellers on the rotating shaft to increase the fire extinguishing efficiency of small items, but the impeller installed on the upper part of the rotating shaft is an axial flow impeller capable of sucking floating objects such as scums to the bottom of the water surface. And, the impeller installed in the middle of the rotating shaft has a hydrofoil type impeller to maintain the sludge homogeneously through sufficient flow inside the digester, and the impeller installed in the lower part of the rotating shaft collects sediment from the lower part of the digester. It can be composed of a radial flow impeller that can be lifted.

The support plate 60 is a disk-shaped lid, supports by coupling a driving unit 70 to be described later, and seals an opening formed in the anaerobic digester.

Here, a sealing member is positioned between the support plate 60 and the opening to seal the support plate 60 and the opening.

The driving unit 70 includes a motor, a reduction gear and a driving gear.

The motor rotates to rotate the rotary pipe 40 to which the impeller 50 is coupled.

The reduction gear coupled with the motor to rotate the impeller 50 installed inside the anaerobic digester obtains a high rotational force that can efficiently agitate the digested products at an appropriate speed when rotating the impeller 30 to stir the sludge inside the digester. For this purpose, it may be configured to rotate by engaging a gear having a diameter larger than the diameter of the gear installed on the rotation shaft of the motor.

The reduction gear reduces the number of revolutions per minute of the rotating pipe 40 that rotates the impeller 50 installed inside the digester by rotating the high rotational speed from the motor by meshing a drive gear with a small diameter and a rotating pipe gear with a large diameter. While it is configured to have a high rotational force, a higher rotational force is transmitted to the rotational pipe 40 of the impeller 50, so that the impeller 50 can be rotated with a small motor, so electricity required for maintenance and management of the anaerobic digester. You can save energy.

The drive gear is installed in the drive unit 70 and serves to transmit the driving force generated by the motor and the reduction gear to the rotating pipe gear.

The rotating pipe gear is fixed to one end of the rotating pipe and serves to convert a driving force generated from the driving gear into a rotational motion of the rotating pipe 40.

The gear fixing part is fixed to the support plate 60 to perform a role of fixing the rotation pipe gear and the rotation pipe 40, as well as a bearing installed at a portion in contact with the rotation pipe gear. It plays a role of assisting smooth rotation.

Considering the number of revolutions per minute of the impeller 50 required to stir the sludge inside the anaerobic digester and the rotational force of the rotating pipe 40 that rotates the impeller 50, the number of revolutions generated by the motor is determined by a gear having a small diameter and a diameter of It is configured to transmit high rotational force to the impeller 50 through two deceleration steps by meshing large gears, and it can be designed and manufactured to obtain an appropriate number of rotations and rotational force by decelerating once or more as needed.

8 to 10 show the main configurations of the dewatering device 10, the sludge drying device 20, and the dewatering device and the sludge drying device 1 according to an embodiment of the present invention.

8 to 10, a dewatering device and a sludge drying device 1 according to an embodiment of the present invention include a dewatering device 10, a sludge drying device 20, and a dry sludge conveying conveyor 30. .

Referring to FIG. 8, the dewatering device 10 according to an embodiment of the present invention includes a filter plate 11, a filter plate mounting cylinder 12, a cleaning trap 13, a dripping fan 14, and a dewatering sludge transfer conveyor ( 15) and a washing water drain pipe (16).

Hereinafter, the dehydration device 10 will be described in more detail.

The sludge introduced into the dewatering facility is supplied to the inside of the filter cloth inside the filter chamber, and the filtrate passed through the filter cloth by the sludge supply pressure is discharged to the outside through the discharge port through the washing trap 13 installed under the filter plate 11 and passed through the filter cloth. The unsuccessful solids undergo primary dehydration through the process of remaining inside. In order to increase the drying efficiency of the rear end, the amount of sludge input is adjusted so that the thickness of the cake is 20 mm or less.

The cake collected inside the filter chamber expands the diaphragm using high-pressure compressed water and is compressed by the expanded diaphragm. The dehydrated and compressed sludge remains inside the filter cloth, and the desorption filtrate is discharged out of the dehydrator and undergoes a secondary dehydration process.

After the secondary dewatering is completed, the compressed water remaining in the diaphragm is discharged to the outside of the dewatering device 10 while the sludge is compressed, and all the filter plates 11 are opened at regular intervals by operation of the filter plate mounting cylinder 12 and compressed. The sludge is discharged to the bottom. In order to peel off the remaining sludge remaining on the filter plate 11, the filter cloth moves downward and then moves upward again.

The dewatered sludge peeled off from the dewatering device 10 and the filter plate 11 is accumulated in the dripping pan 14 under the dehydrator, and after the dewatered sludge discharging process is completed, the dripping pan 14 is opened and the dewatered sludge transfer conveyor 15 at the bottom. ). Thereafter, the dewatered sludge is alternately transferred to the dewatered sludge inlet 22 of the sludge drying apparatus 20 to be described later by using a forward and reverse rotation operation of the dewatered sludge conveying conveyor 15.

9, the sludge drying apparatus 20 according to an embodiment of the present invention includes a sludge drying case 21, a dewatered sludge inlet 22, a dewatered sludge crushing unit 23, an exhaust gas outlet 24, and hot air. The hot air distribution unit 25 including the supply port 25-1, the hot air distribution container 25-2, the hot air dispersion shade 25-3, the dispersion shade support 25-4, and a dry sludge discharge conveyor 26 -1), a door (26-2), an upper mixer (26-3) and a lower mixer (26-4) including a dry sludge discharge portion (26), a sludge flat portion (27), a heating jacket (28-1) ) And a heating unit 28 including an insulating material 28-2.

Hereinafter, the sludge drying apparatus 20 will be described in more detail.

The dewatered sludge discharged through the dewatering device 10 is crushed to a certain size by the dewatered sludge crushing unit 23 attached to the dewatered sludge inlet 22, and then into the drying case 21 of the sludge drying device 20. It is injected, and the sludge flat portion 27 installed on the upper side of the drying case 21 is rotated so that the dewatered sludge does not accumulate in one direction inside the drying facility, so that the hot air coming up from the bottom is evenly distributed.

The sludge drying device 20 consisting of two series is always supplied with hot air to perform the drying process, and the hot air supplied from the external hot air supply device passes through the hot air supply pipe inside the drying facility, and a plurality of hot air supply ports (25-1) The supplied hot air is evenly distributed into the sludge drying device 20 through the hot air distribution tank 25-2 and the hot air dispersing hat 25-3, and passes through the fine pores between the dewatered sludge. And dry through direct heating.

In addition, the hot air dispersing shade (25-3) is manufactured with a sufficiently wider width than the outlet of the hot air distribution tube (25-2), and the position of the end is extended to a position lower than the outlet of the hot air distribution tube (25-2). At the same time, it prevents dewatered sludge moving from the bottom to block the outlet of the hot air distribution tank 25-2 and distributes the supplied hot air evenly to the entire bottom of the dryer.

After drying the dehydrated sludge, the exhaust gas generated is discharged to the atmosphere after being treated in the cleaning tower at the rear through the exhaust gas outlet 24 at the top of the dryer.

In addition, a door 26-2 is installed in the dry sludge discharge unit 26 to prevent the hot air from escaping to the outlet at the bottom of the drying facility.

A certain amount of dried sludge in the sludge drying device 20 that has been dried is taken out alternately according to the series. When carrying out, it is carried out to the outside through the dry sludge discharge conveyor 26-1 and the dry sludge transfer conveyor 30 at the bottom, and at this time, the door 26-2 is opened, and the hot air supply is stopped.

The mixer inside the sludge drying device 20 is composed of an upper mixer (26-3) and a lower mixer (26-4), and the upper mixer (26-3) is intermittent for pulverization and ventilation of the inflow dewatered sludge. Or, perform continuous rotation operation.

The lower mixer 26-4 pulverizes the dehydrated sludge and prevents bridging so that it can be carried out smoothly, and operates in conjunction with the lower sludge discharge conveyor.

The sludge drying device 20 and the sludge drying case 21 include a heating unit 28 including a heating jacket 28-1 and a heat insulating material 28-2, and hot air and hot water are supplied together from an external heat source supply facility. In the case of occurrence, hot water is injected into the heating jacket outside the drying facility so that heat is transferred to the inside of the drying facility, so that direct heating by hot air and complex drying through indirect heating by hot water.

Experimental Example 1: Dehydration device effect verification

After base and acid pretreatment, it was confirmed that the water content of the sludge and the reduction rate of the amount of sludge generation were increased through the installation of a dewatering device which is a filter press dehydration process. This is the result of a demonstration test in August 2018 for sludge in the O industrial complex sewage treatment plant. The sludge input to the dehydrator has a sludge volume of 300㎥/day and an average moisture content of 98.5%. As a result of the operation of the existing dewatering system at the wastewater treatment plant in the O industrial complex, the average moisture content of the dehydrated cake is 74.9% (74.2~75.4%), and the treatment area is the dehydration device applied this time, with an average moisture content of 54.8% (54.0). ~55.0%). The average moisture content reduction rate was 26.9%, and the rate of reduction in the amount of dehydrated cake was 44.6%.

No Dehydrator inflow Dehydrated cake Reduction rate
(AB)÷A Control (A) Treatment section (B) Sludge volume
(㎥/day) Moisture content
(%) Sludge volume
(㎥/day) Moisture content
(%) Sludge volume
(㎥/day) Moisture content
(%) Sludge volume Moisture content One 300 98.6 15.5 74.2 8.9 55.0 25.9% 42.7% 2 300 98.6 16.1 75.2 8.7 54.0 28.2% 46.1% 3 300 98.6 15.9 74.9 8.9 55.0 26.6% 44.2% 4 300 98.3 19.7 75.4 10.8 55.0 27.1% 45.3% Average 300 98.5 16.8 74.9 9.3 54.8 26.9% 44.6%

Experimental Example 2: Heat recovery device installation effect verification

The effect of the installation of the heat recovery device on the energy consumption was confirmed. S Public Sewage Treatment The sludge treatment process was reviewed as a standard, and the amount of digested gas generated was 5,100㎥/day, and the power generation efficiency was 39%, the heat recovery rate was 40%, and the emission and loss of heat was 21% when generating biogas using digested gas. The unit calorific value of extinguishing gas was 5,184kcal/㎥ (methane gas content 60%, see Sewerage Facility Standards (2010)). The amount of heat recovered during biogas power generation was reviewed as 10,575,360kcal/day (= 5,100㎥/day × 5,184kcal/㎥ × 40%). Therefore, it was found that the energy of 10,575,360 kcal/day was reduced through the heat recovery device. When a heat recovery device is not installed, the remaining heat is discharged and consumed except for the 39% power generation efficiency due to biogas power generation.

division unit Contents Remark Bio
gas Generation ㎥/day 5,100 - calorie kcal/day 26,438,400 5,184kcal/㎥Biogas Bio
gas
uses Development kcal/day 10,310,976 Efficiency 39% Heat recovery kcal/day 10,575,360 40% efficiency Release kcal/day 5,552,064 21% efficiency Energy savings due to installation of heat recovery device kcal/day 10,575,360 -

Dewatering device and sludge drying device 1 Dewatering device 10
Filter plate 11 Filter plate mounting cylinder 12
Cleaning trap 13 Dripping pan 14
Dewatered sludge transfer conveyor 15 Rinsing water drain pipe 16
Sludge drying device 20 Sludge drying case 21
Dewatered sludge inlet 22 Dewatered sludge crushing part 23
Exhaust gas outlet 24 Hot air distribution 25
Dry sludge discharge part 26 Dry sludge discharge conveyor 26-1
Door 26-2 Upper mixer 26-3
Lower mixer 26-4 Sludge flat part 27
Heating part 28 Heating jacket 28-1
Insulation material 28-2 Dry sludge transfer conveyor 30
Rotating pipe 40 Impeller 50
Support plate 60 Drive part 70

Claims (12)

Anaerobic digester system that generates biogas and digested sludge by decomposing organic waste,
A dewatering device for generating dewatered sludge by removing moisture from the digested sludge generated in the anaerobic digester device,
Sludge drying apparatus for generating dried sludge by hot air drying the dehydrated sludge,
A biogas generator that generates electricity and heat by using the biogas generated in the anaerobic digester as an energy source, and
Including a heat recovery device for supplying the heat generated by the biogas power generation device to the anaerobic digester device and the sludge drying device
Hybrid biogas pretreatment device.
The method of claim 1,
The dehydration device comprises a pretreatment tank for treating the digested sludge with a base component, a neutralization coagulation tank for treating the digested sludge with an acid component, and a dehydrator for dehydrating the digested sludge treated with a base and an acid Gas pretreatment device.
The method of claim 1,
The sludge drying device includes a sludge dryer for drying the dewatered sludge discharged from the dewatering device, an air preheater and an auxiliary burner to receive a heat source required from the sludge drying device, and drying discharged after reducing the moisture of the dehydrated sludge. Hybrid biogas pretreatment apparatus comprising a odor removal facility for reducing air odor.
The method of claim 1,
The sludge drying apparatus comprises an upper mixer, a lower mixer, or a mixer including an upper mixer and a lower mixer.
The method of claim 4,
The upper mixer pulverizes the introduced dewatered sludge and secures air permeability, and the lower mixer pulverizes the dewatered sludge and prevents bridging.
The method of claim 5,
The dry sludge is a hybrid biogas pretreatment device, characterized in that generated by a heat source recovered from the biogas generator and a heat source generated from the air preheater and auxiliary burner.
The method of claim 1,
The biogas generator is a hybrid biogas pretreatment device, characterized in that it comprises a gas pretreatment facility, an engine generator, and an exhaust gas heat exchanger for recovering heat of exhaust gas generated after combustion of the biogas.
The method of claim 7,
The gas pretreatment facility includes a dehumidifier and a dehumidification cooler for removing moisture contained in the biogas, a heat exchanger for raising the temperature of the cooled biogas by utilizing the cooling heat of an auxiliary heat source cooling device, and a siloxane contained in the biogas. A hybrid biogas pretreatment apparatus comprising a siloxane removal device to remove, a gas booster for increasing the pressure of the biogas, a flow meter, and a gas filter.
The method of claim 8,
The engine generator is a generator body that generates electricity by burning biogas, jacket cooling device and auxiliary heat source cooling device for recovering internal heat generated during biogas combustion and cooling heat of auxiliary jacket, and exhaust gas for recovering exhaust gas heat source. Hybrid biogas pretreatment device comprising a heat exchanger.
The method of claim 9,
The heat recovered from the jacket cooling device of the engine generator is supplied to a heat source required for heating the anaerobic digester device and a heat source required for the sludge drying device through the heat recovery device.
The method of claim 1,
The heat recovery device is a first heat exchanger for recovering the waste heat generated from the biogas generator to heat the anaerobic digester device, and when heating of the anaerobic digester device is not required, the heat source is directly supplied to the sludge drying device. Hybrid biogas pretreatment device, characterized in that it comprises a three-way valve.
The method of claim 11,
The heat recovery device further comprises a second heat exchanger capable of supplementing the heat source of the sludge drying device.

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