Food waste oil recovery system using cooking device

Abstract

The present invention relates to a system for producing biodiesel raw materials and biogas from food waste leachate and condensed wastewater generated during the pretreatment process of food waste using a steamer. The present invention provides a system for recovering waste oil from food waste utilizing a steamer, which can produce biodiesel fuel by recovering waste oil from wastewater generated in the pretreatment process of food waste using a combined batch combination of a food waste dehydrator and a food waste steamer, and can also produce biogas by anaerobic digestion of condensation wastewater generated in the drying process of food waste in a digester, thereby efficiently and economically treating pollutants such as wastewater and condensation wastewater through this process, while also ensuring smooth fluidity of the wastewater and increasing the amount of waste oil that can be separated from the wastewater by adopting a method of raising the temperature of the wastewater by heat exchange between the high-temperature steam condensation heat water discharged from the dryer side and the wastewater in the wastewater storage tank side.

Description

Technology Field

[0001] The present invention relates to a system for recovering waste oil from food waste using a steamer, and more specifically, to a system for producing biodiesel raw materials and biogas from wastewater and condensed wastewater generated during the pretreatment process of food waste using a steamer. Background Technology

[0003] Generally, food waste is recycled into compost or animal feed through volume reduction processes such as dehydration or drying, and resource recovery processes.

[0004] Currently, the food waste resource recovery process incurs significant economic losses due to the excessive energy input required for feed production. Furthermore, serious environmental pollution and resource waste are caused by the direct discharge of wastewater containing large quantities of recyclable solids during the process of separating solids from leachate.

[0005] For example, the discharge volume of food waste leachate and condensate generated during the pretreatment and drying processes of food waste is increasing every year, and there is a demand for technology that can treat this leachate and condensate to minimize environmental pollution.

[0006] Common methods for treating food waste leachate and condensate include combustion treatment, which separates the waste into solids and liquids and then burns the solids, and drying treatment, which reduces the volume of the waste by applying heat to vaporize the liquids and dry the solids.

[0007] These methods require improvement due to issues such as the need for large amounts of energy and the generation of harmful substances like dioxins through combustion, which causes additional environmental pollution.

[0008] Accordingly, the present invention aims to devise a system that reduces the amount of wastewater and condensed wastewater discharged from the pretreatment and drying processes of food waste, while recovering wastewater from the wastewater to produce biodiesel fuel, and anaerobic digesting the condensed wastewater to produce biogas. Prior art literature

[0010] Korean Registered Patent No. 10-2540706, Korean Registered Patent No. 10-1599424, Korean Registered Patent No. 10-2280063, Korean Registered Patent No. 10-0688279 The problem to be solved

[0011] Accordingly, the present invention has been devised in consideration of these points, and aims to provide a system for recovering waste oil from food waste utilizing a steamer, which can produce biodiesel fuel by recovering waste oil from wastewater generated in the pretreatment process of food waste using a combined batch combination of a food waste dehydrator and a food waste steamer, and in addition, produce biogas by anaerobic digestion of condensed wastewater generated in the drying process of food waste in a digester, thereby efficiently and economically treating pollutants such as wastewater and condensed wastewater through this process.

[0012] In addition, another objective of the present invention is to provide a food waste waste oil recovery system utilizing a steamer that can increase the amount of waste oil obtainable by separation from the wastewater by adopting a method of raising the temperature of the wastewater by heat-exchanging high-temperature steam condensation hot water discharged from the dryer side with the wastewater in the wastewater storage tank side, thereby ensuring smooth fluidity of the wastewater. means of solving the problem

[0014] To achieve the above objective, the food waste waste oil recovery system utilizing a steamer provided in the present invention has the following features.

[0015] The food waste waste oil recovery system utilizing the above-mentioned steamer is a part for the pretreatment of food waste brought in from the outside, comprising a crusher / sorter, a primary food waste dehydrator, a food waste steamer, a secondary food waste dehydrator, a food waste sludge storage tank, and a food waste leachate intermediate storage tank; the system comprises a pretreatment part that first dehydrates food waste in the primary food waste dehydrator, then steams the first-dehydrated food sludge in the food waste steamer, then secondarily dehydrates the steamed food sludge in the secondary food waste dehydrator, while storing the secondarily dehydrated food sludge in the food sludge storage tank, and storing the food waste leachate discharged from the primary and secondary food waste dehydrators in the food waste leachate intermediate storage tank; a disc dryer for drying the food sludge fed from the food sludge storage tank of the pretreatment part; and a device for separating and recovering oil from the food waste leachate discharged from the food waste leachate intermediate storage tank of the pretreatment part. It is characterized by including a waste oil recovery part and a dry exhaust gas treatment part that condenses the dry exhaust gas discharged from the disc dryer and supplies the condensed wastewater discharged during this process to a biogas production part to be used for producing biogas.

[0016] As a preferred embodiment, the pretreatment part may further include a food sludge bypass line installed between the primary food dehydrator and the food sludge storage tank, which discharges the food sludge discharged from the primary food dehydrator directly to the food sludge storage tank without passing through the food simmerer and the secondary food dehydrator.

[0017] As a preferred embodiment, the waste oil recovery part may include a primary three-phase separator for separating waste oil and solids from wastewater flowing in from an intermediate wastewater storage tank, a wastewater storage tank for storing wastewater flowing in from the primary three-phase separator, a secondary three-phase separator for separating waste oil and solids from supernatant wastewater flowing in from the wastewater storage tank, and a waste oil storage tank for storing waste oil flowing in from the primary three-phase separator and the secondary three-phase separator.

[0018] In a preferred embodiment, the drying flue gas treatment part may include a cyclone for collecting drying flue gas and fugitive dust introduced from a disc dryer, a condenser for condensing drying flue gas introduced from the cyclone, a condensation wastewater storage tank for storing condensation wastewater introduced from the condenser, and an oil-water separator for separating oil from a mixture of condensation wastewater and oil after introducing condensation wastewater introduced from the condensation wastewater storage tank and oil introduced from the condenser.

[0019] As a preferred embodiment, the biogas production part may include a digester that anaerobically digests wastewater provided from a wastewater recovery part and condensed wastewater provided from a dry flue gas treatment part, a digestate / sludge storage tank that stores the digestate and sludge discharged from the digester, and a digestate / sludge dewatering machine that dewaters the digestate and sludge flowing in from the digestate / sludge storage tank, and then sends the digestate to a reusable water treatment part while sending the sludge to a sludge storage tank.

[0020] A food waste waste oil recovery system utilizing such a steam generator may further include a water supply tank that stores steam condensation hot water flowing in from a disc dryer, and a food waste water heating heat exchanger that heats the food waste water by exchanging heat between the steam condensation hot water flowing in from the water supply tank and the food waste water flowing in from an intermediate storage tank.

[0021] Accordingly, the wastewater can be heated by exchanging heat between the high-temperature steam condensed hot water circulating between the above-mentioned water supply tank and the wastewater heating heat exchanger and the low-temperature wastewater circulating between the above-mentioned wastewater intermediate storage tank and the wastewater heating heat exchanger.

[0022] In addition, the food waste waste oil recovery system utilizing the above-mentioned steamer may further include a hot water heating heat exchanger installed between a water supply tank and a wastewater heating heat exchanger, which corrects the temperature of the hot water condensed by heat exchange between the steam supplied from the steam header and the hot water condensed by steam, and a steam header that receives steam supplied from a deodorizing incineration boiler and steam supplied from a process steam boiler and supplies steam to the hot water heating heat exchanger. Effects of the invention

[0024] The food waste waste oil recovery system utilizing a steamer provided in the present invention has the following effects.

[0025] 1) By applying a new system that can produce biodiesel fuel by recovering waste oil from the wastewater generated in the pretreatment process of food waste and, in addition, produce biogas by anaerobic digestion of the condensed wastewater generated in the drying process of food waste in a digester, it is possible to efficiently and economically treat pollutants such as wastewater and condensed wastewater through this process, thereby contributing to resource recovery and simultaneously obtaining economic and environmental benefits.

[0026] 2) Through the process of producing biodiesel raw materials and biogasification using food waste leachate and condensed wastewater, pollutants such as food waste leachate and condensed wastewater can be efficiently treated, thereby reducing system operating costs such as outsourcing costs, and there is an effect of actively addressing environmental problems by minimizing the emission of pollutants.

[0027] 3) By adopting a method of raising the temperature of the wastewater by heat-exchanging the high-temperature steam-condensed hot water discharged from the dryer side with the wastewater circulated to the wastewater storage tank side while correcting the temperature of the steam condensed hot water with the steam of the deodorizing incineration boiler, it is possible to secure smooth fluidity of the wastewater and further secure wastewater oil that can be separated from the wastewater.

[0028] 4) By properly mixing dehydrated food sludge discharged from the food dehydrator side of the pretreatment process and dehydrated food sludge brought in from the outside, and then feeding it into the dryer, the amount of waste generated can be minimized, the cost of waste consignment disposal can be reduced, and high-quality organic fertilizer can be provided to farms, etc. Brief explanation of the drawing

[0030] FIG. 1 is a block diagram showing a system for recovering waste food waste oil using a steamer according to an embodiment of the present invention. FIG. 2 is a block diagram showing a waste oil recovery part in a food waste waste oil recovery system utilizing a steamer according to an embodiment of the present invention. FIG. 3 is a block diagram showing a drying flue gas treatment part in a food waste waste oil recovery system utilizing a steamer according to an embodiment of the present invention. FIG. 4 is a block diagram showing a biogas production part in a food waste waste oil recovery system utilizing a steamer according to an embodiment of the present invention. FIG. 5 is a block diagram showing a wastewater heating part in a food waste waste oil recovery system utilizing a steamer according to an embodiment of the present invention. Specific details for implementing the invention

[0031] The present invention will be described in detail below with reference to the attached drawings.

[0032] FIG. 1 is a block diagram showing a system for recovering waste food oil using a steamer according to one embodiment of the present invention.

[0033] As illustrated in FIG. 1, the food waste waste oil recovery system utilizing the above-mentioned steamer can effectively recover waste oil that becomes biodiesel fuel from the wastewater generated during the food waste pretreatment process, and can produce biogas by anaerobic digestion of the condensed wastewater generated during the food waste drying process, while also maximizing the extraction of oil by heat-treating the wastewater generated during the food waste pretreatment process, thereby increasing the production volume of biodiesel raw materials.

[0034] To this end, the food waste waste oil recovery system utilizing the above-mentioned steamer includes a pretreatment part (16) as a means for effectively separating food waste sludge (solids) and food waste water from food waste by using processes such as crushing, sorting, dehydration, and steaming as a part for pretreatment of food waste.

[0035] These pretreatment parts (16) are composed of a raw material hopper (41), a crusher / sorter (10), a conveying device (42), a primary food waste dehydrator (11), a food waste steamer (12), a secondary food waste dehydrator (13), a food waste sludge storage tank (14), as well as an intermediate storage tank (15) connected to the primary food waste dehydrator (11).

[0036] The above raw material hopper (41) serves as a storage tank for food waste and plays the role of temporarily storing food waste.

[0037] The food waste stored in these raw material hoppers (41) is fed to the crusher / sorter (10) by a separate conveying device (not shown), such as a screw conveyor or a belt conveyor.

[0038] Here, the food waste leachate generated by the layer separation phenomenon during the temporary storage and transfer of food waste is introduced into the food waste intermediate storage tank (15) through a separate pipe (not shown).

[0039] The above crusher / sorter (10) serves to crush and sort food waste into appropriate sizes.

[0040] In this crusher / sorter (10), food waste is crushed into an appropriate size and then extruded and discharged through a perforated mesh (not shown) at the bottom, and at the top of the crusher / sorter (10), debris such as floating matter and vinyl is sucked in and collected by a blower (not shown) and then separated and discharged.

[0041] The above transfer device (42) serves to transfer food waste (raw sludge, solids, etc.) crushed in the crusher / sorter (10) to the primary food dehydrator (11).

[0042] Food waste crushed in a crusher / sorter (10) usually has a variety of particle sizes and is mixed with wastewater. If this is fed directly into a primary food dehydrator (11), the dehydration efficiency is reduced due to the small particle size of the solids.

[0043] To prevent this, before the crushed food waste is transferred and fed to the food waste steamer (12), the solids with small particle sizes and the wastewater are separated in the transfer device (42).

[0044] This transfer device (42) may include a primary casing (not shown) structure in the form of a perforated mesh at the bottom of the device casing (not shown) and a secondary casing (not shown) structure that seals the outside of the perforated mesh, and solids with relatively large particle sizes separated from the casing are fed into a primary food waste dehydrator (11) through a separate pipe (not shown) and a transfer line (not shown), and solids with small particle sizes separated from the casing and food waste water are fed into a food waste oil recovery part (18) through a separate pipe (not shown) and a transfer line (not shown).

[0045] The above primary food waste dehydrator (11) serves to dehydrate food waste to a moisture content below a predetermined level.

[0046] In this primary food waste dehydrator (11), the wastewater contained in the food waste before being preheated through the food waste steamer (12) can be dehydrated in the first stage.

[0047] And, the solid material, i.e., food sludge, dehydrated by the above-mentioned primary food dehydrator (11) is sent to the food steamer (12), and the food waste generated through the dehydration process is sent to the food waste intermediate storage tank (15).

[0048] Here, by first dehydrating the crushed raw material of food waste before steaming it, the load of the food steamer (12) can be reduced, and at the same time, the steaming efficiency of the food steamer (12), such as steaming time and steaming performance, can be maximized.

[0049] The above food waste steamer (12) is installed between the first food waste dehydrator (11) and the second food waste dehydrator (13), and serves to boil the food waste sludge discharged after the first dehydration process is completed in the first food waste dehydrator (11) at a predetermined temperature and pressure.

[0050] This food waste steamer (12) can further improve the processing efficiency of food waste sludge during the dehydration process as well as during the drying and resource recovery process in the final disc dryer (17) by inducing thermal hydrolysis of a large amount of fiber and cellulose contained in the food waste sludge.

[0051] For example, by preheating the food waste sludge through steaming after pre-dehydration and before main dehydration, the separation efficiency of the dehydrated wastewater (food wastewater) and solids (food waste sludge) during the main dehydration process can be improved, and in addition, the separation efficiency of animal fats (oils) and vegetable fats (oils) in the food waste sludge can be improved.

[0052] In addition, the drying efficiency of the entire system can be improved by preheating the food sludge using a food steamer (12) before introducing the food sludge into the disc dryer (17).

[0053] For example, by preheating the dehydrated food sludge using waste heat and feeding the heated dehydrated food sludge into a disc-type dryer, the effects of reduced steam usage and increased efficiency inside the dryer, the implementation of a glue zone section at the beginning of the dryer through drying the preheated dehydrated cake, increased drying efficiency, and improved throughput can be obtained.

[0054] In such a food steamer (12), the steam condensation water and residual steam of the disc dryer (17) can be used as a heat source, and additionally, the steam of the deodorizing incineration boiler (39) can be used as a heat source.

[0055] In addition, the above food sludge (e.g., dehydrated food sludge) introduced from the primary food dehydrator (11) can also be introduced into the food sludge steamer (12), and consequently, the food sludge that has undergone a preliminary dehydration process and the food sludge that has undergone a dehydration process from the outside can be steamed together within the food sludge steamer (12).

[0056] The above secondary food dehydrator (13) serves to dehydrate food sludge to a moisture content of 75% or less.

[0057] In this secondary food waste dehydrator (13), most of the wastewater contained in the food waste sludge, which is preheated through the food waste steamer (12) after crushing, can be dehydrated.

[0058] That is, the above secondary food waste dewatering machine (13) dewaters the wastewater in the food waste sludge to the maximum extent.

[0059] And, the solid material dehydrated by the above secondary food dehydrator (13), i.e., food sludge, is sent to the food sludge storage tank (14), and the food waste generated through the dehydration process is sent to the food waste intermediate storage tank (15).

[0060] In this way, by applying a method in which food waste is first dehydrated through a first food waste dehydrator (11), the food sludge that has finished first dehydration is preheated through a food simmerer (12), and the food sludge that has been preheated and heated is dehydrated in a second food waste dehydrator (13), the separation efficiency of food waste and solid matter can be further improved.

[0061] The above food waste sludge storage tank (14) serves to store food waste sludge that has undergone two dehydration processes and one steaming process.

[0062] Accordingly, the food sludge discharged from the secondary food dehydrator (13) is stored in the food sludge storage tank (14), and the food sludge discharged from the food sludge storage tank (14) can be sent to the disc dryer (17).

[0063] In the above-mentioned intermediate storage tank (15), the wastewater discharged from the raw material hopper (41), the wastewater discharged from the primary food dehydrator (11), and the wastewater discharged from the secondary food dehydrator (13) are stored, and the wastewater stored in this way can be heated to a predetermined temperature while circulating with the wastewater heating part (43).

[0064] At this time, the wastewater heating part (43) serves to heat the wastewater to increase the separation efficiency of the wastewater (e.g., liquid phase and solid matter of 1 mm or less) circulating with the wastewater intermediate storage tank (15), and in this wastewater heating part (43), the wastewater can be heated to about 70°C.

[0065] In a preferred embodiment, the pretreatment part (16) has a food sludge bypass line (21) installed between the primary food dehydrator (11) and the food sludge storage tank (14).

[0066] Accordingly, the food sludge discharged from the first food dehydrator (11) can be transferred directly to the food sludge storage tank (14) without passing through the food simmer (12) and the second food dehydrator (13), and consequently, the food sludge bypass line (21) can be effectively utilized in situations such as inspection conditions for maintenance of the food simmer (12), conditions where steaming treatment of the food sludge is not required, or conditions where the amount of food sludge processed is large and the food simmer (12) is overloaded, causing some of the food sludge to be bypassed.

[0067] FIG. 2 is a block diagram showing a waste oil recovery part in a food waste waste oil recovery system utilizing a steamer according to one embodiment of the present invention.

[0068] As illustrated in FIG. 2, the waste oil recovery part (18) includes a primary three-phase separator (22) for separating waste oil and solids from waste water flowing in from a waste water intermediate storage tank (15), a waste water storage tank (23) for storing waste water flowing in from the primary three-phase separator (22), a secondary three-phase separator (24) for separating waste oil and solids from supernatant waste water flowing in from the waste water storage tank (23), and a waste oil storage tank (25) for storing waste oil flowing in from the primary three-phase separator (22) and the secondary three-phase separator (24).

[0069] The above primary three-phase separator (22) serves to separate oil from the wastewater discharged into the wastewater intermediate storage tank (15), that is, wastewater heated to a predetermined temperature.

[0070] In this primary three-phase separator (22), the separation of oil (oil), solids (sludge), and liquids (food waste) takes place.

[0071] That is, the heated wastewater is separated into oil, solids, and final wastewater with maximum efficiency in the primary three-phase separator (22), thereby minimizing the oil content and solid content in the final wastewater.

[0072] Then, the oil separated from the first three-phase separator (22) is transferred to the waste oil storage tank (25) for storage and then shipped and sold as a raw material for biodiesel, and the wastewater separated from the first three-phase separator (22) is stored in the wastewater storage tank (23). At this time, the supernatant wastewater among the wastewater is sent to the second three-phase separator (24), and the lower wastewater is sent to the food waste sludge storage tank (14) for drying and processing, and is finally processed into a product such as feed along with dewatering and cake formation, and the solid material separated from the first three-phase separator (22) is also sent to the food waste sludge storage tank (14) for drying and processing.

[0073] Here, the wastewater fed into the first three-phase separator (22) is heated twice as it passes through the food waste steamer (12) and the wastewater heating part (43), so the separation efficiency between the oil and liquid phases can be improved (for example, the separation efficiency between the oil and liquid phases can be increased by raising the temperature of the oil component in the food waste with a steamer before the three-phase separation process), and consequently, there is an economic advantage in that the production volume of oil can be greatly increased, and profits increase due to the increase in oil sales costs.

[0074] The above-mentioned food waste storage tank (23) serves to store the final separated food waste, i.e., liquid waste.

[0075] This food waste storage tank (23) is equipped with a separate heating device (not shown), and the temperature of the stored food waste can be corrected and preheated using the heating device.

[0076] The above secondary three-phase separator (24) serves to separate oil from the wastewater discharged into the wastewater storage tank (23) once more.

[0077] That is, the wastewater is separated into oil, solids, and final wastewater with maximum efficiency in a secondary three-phase separator (24), thereby minimizing the oil content and solid content in the final wastewater.

[0078] Then, the oil separated from the second three-phase separator (24) is transferred to the waste oil storage tank (25) for storage and then shipped and sold as a raw material for biodiesel. In addition, the wastewater separated from the second three-phase separator (24) is sent to the biogas production part (19) to be used for producing biogas. At this time, the solid material separated from the second three-phase separator (24) is collected separately and then sent to the food waste sludge storage tank (14) as needed.

[0079] FIG. 3 is a block diagram showing a drying flue gas treatment part in a food waste waste oil recovery system utilizing a steamer according to one embodiment of the present invention.

[0080] As illustrated in FIG. 3, a disc dryer (17) for drying food waste sludge and a drying exhaust gas treatment part (20) for treating the drying exhaust gas discharged after drying treatment are shown.

[0081] The above disc dryer (17) serves to dry the food sludge introduced from the food sludge storage tank (14) of the pretreatment part (16), and the drying exhaust gas generated during this process is sent to the drying exhaust gas treatment part (20), while the solid material is sent to the posttreatment part (44).

[0082] And, the above-mentioned dry exhaust gas treatment part (20) includes a cyclone (26) for collecting dry exhaust gas and flying dust introduced from a disc dryer (17), a condenser (27) for condensing dry exhaust gas introduced from the cyclone (26), a condensed wastewater storage tank (28) for storing condensed wastewater introduced from the condenser (27), and an oil-water separator (29) for separating oil from a mixture of condensed wastewater and oil after introducing condensed wastewater introduced from the condensed wastewater storage tank (28) and oil introduced from the condenser (27).

[0083] The above cyclone (26) is a wet cyclone and is a device capable of collecting drying exhaust gas and airborne dust generated when drying food sludge in a disc dryer (17).

[0084] The airborne dust captured in this cyclone (26) can be fed back into the disc dryer (17), thereby increasing the production of drying resources such as fertilizer.

[0085] That is, by reintroducing the airborne dust collected in the wet cyclone (26) into the disc dryer (17), the cost of entrusting the disposal of airborne dust and suspended matter as in the past can be reduced, and at the same time, more dried resources can be produced by proceeding with the drying resource recovery process, which is very advantageous in terms of economy.

[0086] The above condenser (27) is a device for condensing exhaust gas discharged from a disc dryer (17), that is, dry exhaust gas from which airborne dust and the like have been removed by passing through a wet-type cyclone (26), and is composed of a first condenser (27a) and a second condenser (27b) arranged sequentially.

[0087] The above primary condenser (27a) serves to remove oil from the drying exhaust gas generated during the drying of food sludge in the disc dryer (17), and the oil removed from the primary condenser (27a) can be sent to the oil-water separator (29).

[0088] This primary condenser (27a) can maintain a temperature of about 60 to 70°C with a jacket-type structure.

[0089] At this time, if the temperature of the primary condenser (27a) is maintained at 70°C or higher, the oil in the dry exhaust gas moves to the secondary condenser (27b), causing the contamination level of the condensate to increase.

[0090] And, if the temperature of the primary condenser (27a) is maintained at less than 60°C, moisture is condensed along with the condensation of oil and oil in the dry exhaust gas, so the contamination of the condensate in the secondary condenser (27b) can be reduced, but the amount of primary condensate generated in large quantities increases, causing a decrease in the final waste processing amount of the disc dryer (17).

[0091] Accordingly, it is desirable to maintain the temperature of the primary condenser (27a) at around 60 to 70°C.

[0092] Here, the heat source for the primary condenser (27a) may be the steam condensation water of the disc dryer (17), and if insufficient, the steam of the deodorizing incineration boiler (39) used for odor combustion and incineration may be used as the heat source.

[0093] The above secondary condenser (27b) serves to condense and process the dry exhaust gas from which oil has been removed in the primary condenser (27a) after foreign substances such as flying dust have been removed in the cyclone (26).

[0094] This secondary condenser (27b) has a Shell & Tube type structure and can maintain a temperature of about 50 to 60°C.

[0095] And, any remaining gas and odor substances not removed in the secondary condenser (27b) can be sent to the deodorizing incineration boiler (39) to be completely removed, and the condensed wastewater discharged from the secondary condenser (27b) can be sent to the condensed wastewater storage tank (28) for storage and then supplied to the biogas production part (19).

[0096] Here, if the temperature of the secondary condenser (27b) is maintained at 60°C or higher, the amount of residual gas processed into the deodorizing incineration boiler (39) increases, which has the disadvantage of increasing the operating cost of the deodorizing incineration boiler (39).

[0097] In addition, if the temperature of the secondary condenser (27b) is maintained below 50°C, there is a disadvantage that the operating cost of the recycled water treatment part (32) or the process water treatment facility (not shown) increases due to an increase in the amount of wastewater condensed in the secondary condenser (27b) as well as an increase in the contamination load of the condensed water.

[0098] The above oil-water separator (29) serves to separate oil from a mixture of condensed wastewater and water after receiving condensed wastewater discharged from the condensed wastewater storage tank (28) as well as oil discharged from the primary condenser (27a).

[0099] The two types of condensed wastewater separated in such an oil-water separator (29) can be sent to the primary three-phase separator (22) and the biogas production part (19), respectively.

[0100] That is, the condensed wastewater with a relatively high oil content is sent to the primary three-phase separator (22) and stored in the wastewater storage tank (23), while the condensed wastewater with a relatively low oil content is appropriately distributed and sent to the recycled water treatment part (32) and the biogas production part (19), respectively.

[0101] As a preferred embodiment, a post-treatment part (44) for performing a post-treatment process for the dried material discharged from the disc dryer (17) may be provided, and the post-treatment part (44) is a part for post-treating food waste sludge discharged from the disc dryer (17).

[0102] These post-processing parts (44) may include a magnetic separator (not shown), a primary crusher (not shown), a cooling separator (not shown), a secondary crusher (not shown), a primary product separator (not shown), a secondary product separator (not shown), etc. that are connected sequentially.

[0103] FIG. 4 is a block diagram showing a biogas production part in a food waste waste oil recovery system utilizing a steamer according to an embodiment of the present invention.

[0104] As illustrated in FIG. 4, the biogas production part (19) includes a digester (30), a digestate / sludge storage tank (31), a digestate / sludge dewatering machine (34), etc.

[0105] The above digester (30) serves to anaerobically digest not only the wastewater supplied from the secondary three-phase separator (24) of the wastewater recovery part (18) but also the condensed wastewater supplied from the condensed wastewater storage tank (28) of the dry exhaust gas treatment part (20).

[0106] That is, the above digester (30) is a digester in which the internal temperature is maintained at approximately 37 to 42°C, and in this digester (30), food waste and condensed waste are anaerobically digested.

[0107] For example, when food waste with a relatively high level of contamination and condensed waste with a relatively low level of contamination are introduced into the digester (30), the food waste and condensed waste are retained in the digester for a period of about 25 to 35 days and the pH is maintained at 7.0 to 7.6. The biogas generated through this retention and fermentation process is collected at the top of the digester, the digested liquid is collected at the upper layer of the water level inside the digester, and the heavy sludge is collected at the lower layer inside the digester.

[0108] Here, the biogas produced in the digester (30) is sent to a biogas storage tank (not shown) for storage, and is also sent to a biogas pretreatment unit (not shown) to undergo treatments such as dust removal, dehumidification, and desulfurization. The biogas produced through this process is sold as city gas, etc.

[0109] In this way, the above digester (30) can increase the production of biogas by appropriately mixing food waste with a relatively high level of contamination and condensed waste with a relatively low level of contamination and then anaerobic digesting them. Also, in the case of the food waste and condensed waste being digested in the digester (30), the oil that hinders microbial growth (activity) during anaerobic digestion has been extracted to the maximum extent, so the production of biogas can be further increased as active anaerobic digestion proceeds.

[0110] The above digestion liquid / sludge storage tank (31) serves to store and mature the digestion liquid and sludge discharged from the digestion tank (30).

[0111] That is, the above digestion liquid / sludge storage tank (31) plays the role of retaining the digestion liquid and sludge discharged from the digestion tank (30) for a while while performing the fermentation maturation process and the solid-liquid separation process.

[0112] After undergoing the maturation process in the digestion liquid / sludge storage tank (31), the digestion liquid and digestion liquid discharged are sent to the digestion liquid / sludge dewatering machine (34) for dewatering treatment.

[0113] The above digestion liquid / sludge dewatering machine (34) dewaters the digestion liquid and sludge discharged from the digestion liquid / sludge storage tank (31), and then sends the digestion liquid to the water reuse treatment part (32), and at the same time sends the sludge to the sludge storage tank (33).

[0114] The above-mentioned water reuse treatment part (32) includes a purification treatment / water reuse treatment process part (45).

[0115] The above purification / reusable water treatment process unit (45) plays the role of purifying the digestate discharged from the digestate / sludge storage tank (31) and also plays the role of reusing the treated water.

[0116] And, the recycled water discharged from the above purification / recycled water treatment process unit (45) can be reused as cooling circulation water for the condenser (27), etc.

[0117] As an example, the recycled water (e.g., condensate that can be discharged due to low contamination) treated in the above purification / recycled water treatment process unit (45) is not discharged as before, but can be used as recycled water when replenishing cooling water due to the scattering evaporation of cooling water circulating in the secondary condenser (27b).

[0118] Here, in the above purification / reuse water treatment process unit (45), the digestate generated during the anaerobic digestion process contains high concentrations of organic matter, total nitrogen, and non-degradable substances, and at the same time, the temperature is very high. Therefore, after cooling with a pretreatment facility, the non-degradable substances are treated with an advanced oxidation device, then treated with a biological treatment (MBR) process to remove suspended solids, organic matter, and nitrogen components, and then reused after a post-treatment process with an RO filtration device.

[0119] To this end, the purification / reuse water treatment process unit (45) may include a conventional pumping tank, a collection tank, a cooling and homogenization tank, an ozone and cooling reaction tank, a flow rate adjustment tank, an aeration tank, a biological sedimentation tank, an immersed membrane tank, a filtered water tank, an RO filter, a reuse water tank, etc. that are connected in sequence.

[0120] FIG. 5 is a block diagram showing a wastewater heating part in a food waste wastewater recovery system utilizing a steamer according to one embodiment of the present invention.

[0121] As illustrated in FIG. 5, the above-mentioned wastewater heating part (43) excludes the method of heating wastewater using steam as a heat source to increase oil extraction in the pretreatment part (16), and instead applies a method of heating wastewater using high-temperature steam condensation hot water discharged from the dryer side as a heat source, thereby solving problems such as the wastewater sticking when heating wastewater and ensuring smooth fluidity of wastewater, and ultimately increasing the heating efficiency of wastewater to increase the production volume of biodiesel raw materials.

[0122] This food waste water heating part (43) can heat the food waste water by exchanging heat between the high-temperature steam condensed hot water circulating between the water supply tank (35) and the food waste water heating heat exchanger (36) and the low-temperature food waste water circulating between the food waste water intermediate storage tank (15) and the food waste water heating heat exchanger (36).

[0123] To this end, the above-mentioned wastewater heating part (43) includes a water supply tank (35) for storing steam condensed hot water.

[0124] The above-mentioned water supply tank (35) is connected to the disc dryer (17) by a line, thereby enabling it to receive steam condensation water discharged from the disc dryer (17) (e.g., steam condensation water used in the food sludge drying process).

[0125] At this time, the steam condensation water can be maintained at a temperature of about 100°C.

[0126] And, the above-mentioned water supply tank (35) is connected by a line to the deodorizing incineration boiler (39) and the process steam boiler (40), and accordingly, the steam condensation hot water supplied from the water supply tank (35) can be used as process water (water supply) for the deodorizing incineration boiler (39) and the process steam boiler (40).

[0127] In particular, the above-mentioned water supply tank (35) is connected by a line to the hot water heating heat exchanger (38) and the wastewater heating heat exchanger (36), thereby enabling circulation of hot water between the water supply tank (35), the hot water heating heat exchanger (38), and the wastewater heating heat exchanger (36).

[0128] Additionally, the above-mentioned wastewater heating part (43) includes a wastewater heating heat exchanger (36) as a means for heat exchange of wastewater.

[0129] The above-mentioned wastewater heat exchanger (36) serves to heat the wastewater by utilizing the heat exchange action between the steam condensation hot water and the wastewater.

[0130] These wastewater heating heat exchangers (36) are each connected by lines to the hot water heating heat exchanger (38), the water supply tank (35), and the wastewater intermediate storage tank (15).

[0131] Accordingly, the steam condensation hot water supplied from the water supply tank (35) (e.g., steam condensation hot water of about 80 to 90°C) is circulated through the path of the hot water heating heat exchanger (38) → food waste water heating heat exchanger (36) → water supply tank (35), and the food waste water is circulated between the food waste water intermediate storage tank (15) and the food waste water heating heat exchanger (36), and through this process, heat exchange between the food waste water and the steam condensation hot water takes place inside the food waste water heating heat exchanger (36), thereby allowing the food waste water to be heated.

[0132] Additionally, the above-mentioned wastewater heating part (43) includes a hot water heating heat exchanger (38) as a means for heat exchange of steam condensed hot water.

[0133] The above hot water heating heat exchanger (38) serves to compensate for the drop in temperature of the steam condensation hot water stored inside the water supply tank (35) by exchanging heat with steam.

[0134] That is, the above-mentioned hot water heating heat exchanger (38) is installed between the water supply tank (35) and the wastewater heating heat exchanger (36) and serves to correct the temperature of the steam condensation hot water through heat exchange between the steam supplied from the deodorizing incineration boiler (39) through the steam header (37) and the steam condensation hot water.

[0135] This hot water heating heat exchanger (38) is connected to the water supply tank (35) by two lines, so that hot water can be supplied from the water supply tank (35) to the hot water heating heat exchanger (38), and at the same time, steam condensation hot water can be discharged from the hot water heating heat exchanger (38) to the water supply tank (35) after steam use.

[0136] In addition, the hot water heating heat exchanger (38) is connected by a line to the wastewater heating heat exchanger (36), so that steam condensation hot water can be supplied from the hot water heating heat exchanger (38) to the wastewater heating heat exchanger (36).

[0137] And, the hot water heating heat exchanger (38) is connected to the steam header (37) by a line, so that steam supplied from the steam header (37) can be supplied to the hot water heating heat exchanger (38).

[0138] Accordingly, when the temperature of the steam condensation hot water in the water supply tank (35) drops below a preset temperature (e.g., about 100°C), steam is supplied from the steam header (37) and steam condensation hot water is supplied from the water supply tank (35) to the hot water heating heat exchanger (38), and as a result, heat exchange between the steam and the steam condensation hot water takes place inside the hot water heating heat exchanger (38), thereby heating the steam condensation hot water and compensating for the temperature.

[0139] In a preferred embodiment, the steam condensation hot water of the water supply tank (35) is used as water for the deodorizing incineration boiler (39) and the process steam boiler (40), respectively, and the steam produced in the deodorizing incineration boiler (39) and the process steam boiler (40) is distributed from the steam header (37) and sent to the disc dryer (17) and the hot water heating heat exchanger (38), respectively, so that it can be used for drying food waste sludge and for heating the steam condensation hot water.

[0140] In this way, the present invention provides a system utilizing a combined arrangement of a food waste dehydrator and a food waste steamer, thereby enabling the production of biodiesel fuel by recovering waste oil from food waste generated in the food waste pretreatment process and producing biogas by anaerobic digestion of condensed wastewater generated in the food waste drying process in a digester, thereby allowing for the efficient and economical treatment of pollutants such as food waste and condensed wastewater, while also actively addressing resource recycling.

[0141] In addition, the present invention provides a system that raises the temperature of the wastewater by heat-exchanging the high-temperature steam condensation hot water discharged from the dryer side with the wastewater in the wastewater storage tank side, thereby ensuring smooth fluidity of the wastewater and increasing the amount of wastewater oil that can be separated from the wastewater. Explanation of the symbols

[0143] 10: Crusher / Sorter 11: Primary Food Waste Dehydrator 12: Food waste steamer 13: Secondary food waste dehydrator 14: Food waste sludge storage tank 15: Food waste leachate intermediate storage tank 16 : Preprocessing Part 17 : Disc Dryer 18: Waste Food Oil Recovery Part 19: Biogas Production Part 20: Drying Flue Gas Treatment Part 21: Food Waste Sludge Bypass Line 22: Primary three-phase separator 23: Food waste storage tank 24: Secondary three-phase separator 25: Spent oil storage tank 26: Cyclone 27: Condenser 27a: Primary condenser 27b: Secondary condenser 28: Condensed wastewater storage tank 29: Oil-water separator 30: Digester 31: Digestion / Sludge Storage Tank 32: Reused Water Treatment Part 33: Sludge Storage Tank 34: Digestion / Sludge Dewatering Machine 35: Water Supply Tank 36: Wastewater heating heat exchanger 37: Steam header 38: Hot water heating heat exchanger 39: Deodorizing incineration boiler 40: Process steam boiler 41: Raw material hopper 42: Transfer device 43: Wastewater heating part 44: Post-treatment Part 45: Purification / Reusable Water Treatment Process Section

Claims

Claim 1 A pretreatment part (16) for pretreatment of food waste brought in from the outside, comprising a crusher / sorter (10), a primary food waste dehydrator (11), a food waste steamer (12), a secondary food waste dehydrator (13), a food waste sludge storage tank (14), and a food waste leachate intermediate storage tank (15); wherein the food waste is first dehydrated in the primary food waste dehydrator (11), then the primary dehydrated food waste sludge is steamed in the food waste steamer (12), then the steamed food waste sludge is secondarily dehydrated in the secondary food waste dehydrator (13), while the secondary dehydrated food waste sludge is stored in the food waste sludge storage tank (14), and the food waste leachate discharged from the primary food waste dehydrator (11) and the secondary food waste dehydrator (13) is stored in the food waste leachate intermediate storage tank (15); the food waste of the pretreatment part (16) A disc dryer (17) for drying food waste sludge introduced from a storage tank (14); a wastewater oil recovery part (18) for separating and recovering oil from the wastewater discharged from the wastewater intermediate storage tank (15) of the pretreatment part (16); a drying exhaust gas treatment part (20) for condensing the drying exhaust gas discharged from the disc dryer (17) and supplying the condensed wastewater discharged in this process to a biogas production part (19) to be used for producing biogas; and a water supply tank (35) for storing steam condensation heat water introduced from the disc dryer (17), a wastewater heating heat exchanger (36) for heating the wastewater by heat-exchanging the steam condensation heat water introduced from the water supply tank (35) and the wastewater intermediate storage tank (15), and high-temperature steam condensation heat water circulating between the water supply tank (35) and the wastewater heating heat exchanger (36) and the wastewater intermediate A food waste waste oil recovery system utilizing a steamer, characterized by heating the food waste water by exchanging heat between the storage tank (15) and the food waste water heating heat exchanger (36) for low-temperature food waste water. Claim 2 A food waste waste oil recovery system utilizing a steamer according to claim 1, wherein the pretreatment part (16) is installed between a primary food dehydrator (11) and a food sludge storage tank (14) and further includes a food sludge bypass line (21) that discharges food sludge discharged from the primary food dehydrator (11) directly to the food sludge storage tank (14) without passing through a food steamer (12) and a secondary food dehydrator (13). Claim 3 A food waste waste oil recovery system utilizing a steamer according to claim 1, wherein the food waste oil recovery part (18) comprises a primary three-phase separator (22) for separating food waste oil and solids from food waste water flowing in from a food waste water intermediate storage tank (15), a food waste water storage tank (23) for storing food waste water flowing in from the primary three-phase separator (22), a secondary three-phase separator (24) for separating food waste oil and solids from supernatant food waste water flowing in from the food waste water storage tank (23), and a food waste oil storage tank (25) for storing food waste oil flowing in from the primary three-phase separator (22) and the secondary three-phase separator (24). Claim 4 A food waste waste oil recovery system utilizing a steamer according to claim 1, wherein the drying exhaust gas treatment part (20) comprises a cyclone (26) for collecting drying exhaust gas and flying dust introduced from a disc dryer (17), a condenser (27) for condensing drying exhaust gas introduced from the cyclone (26), a condensed wastewater storage tank (28) for storing condensed wastewater introduced from the condenser (27), and an oil-water separator (29) for separating oil from a mixture of condensed wastewater and oil after introducing condensed wastewater introduced from the condensed wastewater storage tank (28) and oil introduced from the condenser (27). Claim 5 A food waste waste oil recovery system utilizing a steamer according to claim 1, wherein the biogas production part (19) comprises a digester (30) that anaerobically digests wastewater provided from the waste oil recovery part (18) and condensed wastewater provided from the dry flue gas treatment part (20), a digester / sludge storage tank (31) that stores the digester and sludge discharged from the digester (30), and a digester / sludge dewatering machine (34) that dewaters the digester and sludge flowing in from the digester / sludge storage tank (31), and then sends the digester to the reusable water treatment part (32) while sending the sludge to the sludge storage tank (33). Claim 6 delete Claim 7 A food waste waste oil recovery system utilizing a steamer according to claim 1, further comprising a hot water heating heat exchanger (38) installed between the water supply tank (35) and the food waste water heating heat exchanger (36) and correcting the temperature of the steam condensation hot water through heat exchange between the steam supplied from the steam header (37) and the steam condensation hot water, and a steam header (37) that receives steam supplied from the deodorizing incineration boiler (39) and steam supplied from the process steam boiler (40) and supplies steam to the hot water heating heat exchanger (38).

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