Food waste treatment system using high concentrated organic food waste water

Abstract

The present invention relates to a system for effectively utilizing high-concentration organic wastewater produced by mixing the digested water discharged from a digester with the sludge discharged from a low-speed, three-phase separator, by supplying it to a consumption site, a digester, etc. The present invention provides a food waste treatment system utilizing high-concentration organic food waste by implementing a system that applies methods such as a method of treating high-concentration organic food waste by mixing digested water discharged from a digester with sludge discharged from a low-speed, three-phase separator and supplying it to a consumption site that requires it, a method of utilizing high-concentration organic food waste by supplying it to a digester for biogas production, and a method of increasing biogas production by supplying sludge discharged from a low-speed, three-phase separator to a digester. This enables sufficient supply of high-concentration organic food waste to consumption sites such as wastewater / sewage treatment plants, reduces energy costs by increasing biogas production, and smoothly supplies mixed wastewater containing organic matter of appropriate standards to consumption sites that require it.

Description

Technology Field

[0001] The present invention relates to a food waste treatment system utilizing high-concentration organic food waste, and more specifically, to a system that effectively utilizes high-concentration organic food waste produced by mixing digested water discharged from a digester with sludge discharged from a low-speed, three-phase separator by supplying it to a consumption site, a digester, etc. Background Technology

[0003] Generally, food waste leachate is a high-concentration organic waste liquid discharged from the resource recovery process of food waste.

[0004] This food waste is characterized by a high moisture content, contains easily perishable organic matter, and has a high solid content.

[0005] Currently, the direct landfilling of food waste leachate is prohibited, and local governments also ban the direct landfilling of food waste.

[0006] Typically, food waste is either dumped into the ocean or brought into sewage treatment plants for treatment when its moisture content exceeds 85%. However, since ocean dumping has been completely banned since 2013 under the London Convention, treatment at sewage treatment plants is expected to have adverse effects on treatment facilities due to high concentrations and raise concerns about complaints arising from odors.

[0007] Recently, there has been a trend to minimize the organic matter content of food waste before treating it at sewage treatment plants by methods such as producing biogas using an anaerobic digestion process.

[0008] For example, high-concentration wastewater discharged during the food waste pretreatment process is sent to a digester for anaerobic digestion treatment, and the digester gas produced therefrom undergoes pretreatment processes such as dehumidification, dust removal, and desulfurization, and is then used as boiler fuel, or operated to produce steam or electricity by operating a power generation boiler, or sold as biomass energy, or methane gas is upgraded and sold.

[0009] However, most of the pollutants, such as wastewater or sludge discharged during the digestion process of food waste are entrusted to external treatment, which results in increased costs and disadvantages in terms of cost.

[0010] Furthermore, the process systems of the food waste digestion or drying equipment industry require a large amount of thermal and electrical energy; the high energy costs lead to increased production unit costs, placing a significant burden on business operations.

[0011] Meanwhile, in the food waste pretreatment process, when food waste is introduced, it is sorted, crushed, and dewatered, followed by a solid-liquid separation process. The liquid separated from the dewatered cake through this process is then subjected to low-speed separation and three-phase separation processes to extract oil. After removing impurities from the extracted oil through a sedimentation process, the animal and vegetable oil is finally extracted and sold.

[0012] However, even in the case of food waste pretreatment processes, there are disadvantages in terms of cost, such as the need to outsource the treatment of most of the wastewater or waste discharged from the process. Prior art literature

[0014] Registered Patent Publication No. 10-2918237 Registered Patent Publication No. 10-2885146 Registered Patent Publication No. 10-2792870 Registered Patent Publication No. 10-2720825 The problem to be solved

[0015] Accordingly, the present invention has been devised in consideration of these points, and aims to provide a food waste treatment system utilizing high-concentration organic food waste by implementing a system that applies methods such as a method of mixing digested water discharged from a digester with sludge discharged from a low-speed, three-phase separator to supply and treat high-concentration organic food waste to a consumption site that requires it, a method of supplying high-concentration organic food waste to a digester to utilize it for biogas production, and a method of supplying sludge discharged from a low-speed, three-phase separator to a digester to increase biogas production. This allows for sufficient supply of high-concentration organic food waste to consumption sites such as wastewater treatment plants, reduces energy costs by increasing biogas production, and smoothly supplies mixed wastewater containing organic matter of appropriate standards to consumption sites that require it. means of solving the problem

[0017] To achieve the above objective, the food waste treatment system utilizing high-concentration organic wastewater provided in the present invention has the following features.

[0018] The food waste treatment system utilizing the above-mentioned high-concentration organic food waste leachate includes a low-speed, three-phase separator that separates oil from the food waste leachate produced after dewatering food waste, a #1 digester that digests the food waste leachate supplied from the low-speed, three-phase separator, and a mixing tank that produces high-concentration organic food waste leachate by mixing the digested water discharged from the #1 digester with the sludge discharged from the low-speed, three-phase separator.

[0019] A food waste treatment system utilizing such high-concentration organic food waste leachate is characterized by supplying the high-concentration organic food waste leachate produced in the mixing tank to consumption sites requiring high-concentration organic food waste leachate, such as wastewater treatment plants, and / or to digester #2 for digestion treatment.

[0020] Here, the food waste treatment system utilizing the above-mentioned high-concentration organic food waste may further include a high-concentration organic food waste storage tank installed at the downstream end of the mixing tank, which stores the high-concentration organic food waste discharged from the mixing tank and also uniformly mixes it using an underwater motor stirrer.

[0021] In addition, the food waste treatment system utilizing the above-mentioned high-concentration organic wastewater may send a portion of the sludge discharged from the low-speed, three-phase separator to the mixing and adjusting tank, and then supply it to the #1 digester to be used for purposes such as preserving the concentration of organic matter and replenishing the flow rate.

[0022] As a preferred embodiment, the food waste treatment system utilizing the high-concentration organic food waste may include an intermediate storage hopper for storing sludge produced after dewatering food waste, and accordingly, a portion of the sludge discharged from the low-speed, three-phase separator may be supplied to the intermediate storage hopper, mixed with the sludge in the intermediate storage hopper, and then fed into a dryer for drying treatment. Effects of the invention

[0024] The food waste treatment system utilizing high-concentration organic wastewater provided in the present invention has the following effects.

[0025] 1) By utilizing high-concentration organic wastewater with easy control of organic matter concentration, it can be supplied smoothly to consumers, etc., and by digesting the high-concentration organic wastewater in digester #2, energy costs associated with increased biogas production can be reduced.

[0026] For example, the digested water discharged from the #1 digester is mixed with the sludge discharged from the low-speed, three-phase separator to produce high-concentration organic food waste, and this high-concentration organic food waste is reintroduced into the #2 digester to increase biogas production, thereby reducing the energy costs of the heat generation equipment and increasing the utilization of food waste by supplying it to places that require it, such as wastewater treatment plants.

[0027] 2) #1 When there is a shortage of food waste supply to the digester, the operating efficiency of the digester can be improved by supplying sludge discharged from a low-speed, three-phase separator, and ultimately, the biogas production can be maximized.

[0028] In other words, when there is a shortage of food waste supplied to the #1 digester side and a decrease in concentration, biogas production can be increased by recovering and feeding some of the sludge from the low-speed, three-phase separator side to maintain the concentration of organic matter and replenish the flow rate.

[0029] 3) By recycling the sludge discharged from the low-speed, three-phase separator, the sludge drying treatment load of the dryer can be reduced, and the problem of poor conveying of the screw conveyor caused by viscous sludge in the sludge drying facility can be improved.

[0030] 4) By recycling a portion of the digested water, the outsourcing of digested water treatment can be smooth and outsourcing costs can be reduced.

[0031] 5) By feeding the entire amount of high-concentration organic wastewater, produced by mixing the digested water and sludge, into digester #2, the sludge volume can be reduced and biogas production can be increased. Brief explanation of the drawing

[0033] FIG. 1 is a schematic diagram showing a food waste treatment system utilizing high-concentration organic food wastewater according to an embodiment of the present invention. Specific details for implementing the invention

[0034] The present invention will be described in detail below with reference to the attached drawings.

[0035] FIG. 1 is a schematic diagram showing a food waste treatment system utilizing high-concentration organic wastewater according to one embodiment of the present invention.

[0036] As illustrated in FIG. 1, the food waste treatment system utilizing the high concentration organic wastewater includes a raw material hopper (19), a crusher (20), a dehydrator (21), a wastewater storage tank (22a), etc., as means for receiving, crushing, and dehydrating food waste.

[0037] The above raw material hopper (19) serves to store food waste collected and brought in by a food waste collection vehicle.

[0038] The above crusher (20) serves to crush food waste that is clumped together in the form of lumps, etc.

[0039] The above dehydrator (21) serves to dehydrate the moisture in the food waste.

[0040] The above-mentioned wastewater storage tank (22a) serves to store wastewater (dehydrated liquid) discharged from the dehydrator (21).

[0041] Accordingly, food waste brought in from the outside passes through a raw material hopper (19), a crusher (20), and a dehydrator (21), and through this process, the food waste is finely crushed and the moisture contained in the food waste can be removed.

[0042] And, the organic sludge, i.e., the sludge coming out of the dehydrator (21), is sent to an intermediate storage hopper (17) for storage, and in addition, the wastewater coming out of the dehydrator (21) is sent to a wastewater storage tank (22a) for storage.

[0043] In addition, the food waste treatment system utilizing the above-mentioned high-concentration organic wastewater includes a low-speed, three-phase separator (10) as a means for separating oil from the wastewater supplied from the wastewater storage tank (22a), which is the wastewater produced after dehydrating the food waste.

[0044] The oil extracted from the low-speed, three-phase separator (10) is shipped as a raw material for biodiesel, etc. after undergoing a purification process, and the sludge discharged from the low-speed, three-phase separator (10) is sent to a mixing tank (12), and the wastewater discharged from the low-speed, three-phase separator (10) is sent to a wastewater storage tank (22b) for storage, then passes through a mixing adjustment tank (23) and is sent to the #1 digester (11) for anaerobic digestion treatment.

[0045] At this time, the sludge discharged from the low-speed, three-phase separator (10) is distributed in appropriate proportions, some of which is supplied to the intermediate storage hopper (17), some of which is supplied to the mixing adjustment tank (23), and the rest is supplied to the mixing tank (12).

[0046] In particular, some of the sludge discharged from the above low-speed, three-phase separator (10) is supplied to the #1 digester (11) via the mixing adjustment tank (23), and accordingly, when the supply of food waste water supplied to the #1 digester (11) is insufficient or the concentration decreases, the organic matter concentration and flow rate of the #1 digester (11) can be maintained, and ultimately, the biogas production can be maximized.

[0047] Of course, in the case of sludge distribution, the appropriate distribution of sludge can be achieved manually or automatically by means of a flow control valve (not shown) installed at the branching point of each line.

[0048] In addition, the food waste treatment system utilizing the above-mentioned high-concentration organic wastewater includes a #1 digester (11) as a means to produce biogas by digesting the wastewater supplied from the low-speed, three-phase separator (10), that is, the wastewater discharged from the mixing and adjusting tank (23).

[0049] The above #1 digester (11) is a medium-temperature digester in which the internal temperature is maintained at approximately 38 to 42°C. When food waste is introduced into the #1 digester (11), the food waste is retained and fermented within the digester for a predetermined period of time. The biogas generated through this retention and fermentation process is collected at the top of the digester, the digested water (filtrate) is collected at the upper level of the water level within the digester, and the heavy digested sludge is collected at the lower level of the digester.

[0050] Here, the biogas in the above #1 digester (11) can be used for itself after undergoing a predetermined treatment process, sold after undergoing an electricity production process, or sold as city gas fuel after undergoing a purification process.

[0051] And, the digested water and sludge discharged from the above #1 digester (11) are sent to the aging tank (24a), and the digested water and sludge sent to the aging tank (24a) are retained in the aging tank (24a) for a while and are circulated with the #1 digester (11) to undergo a fermentation aging process and a solid-liquid separation process.

[0052] In addition, the digested water (supernatant) discharged from the aging tank (24a) is sent to a digested water storage tank (25) for storage, and the sludge discharged from the aging tank (24a) is sent to a dryer (18) for drying treatment or can be entrusted to an external facility for treatment.

[0053] At this time, the digestion water discharged from the digestion water storage tank (25) is distributed in appropriate proportions, some of which is entrusted to an external treatment facility, and the remainder is supplied to the mixing tank (12).

[0054] Of course, in the case of distributing the treated water, the appropriate distribution of the treated water can be achieved manually or automatically by means of a flow control valve (not shown) installed at the branching point of each line.

[0055] Meanwhile, the food waste treatment system utilizing the above-mentioned high-concentration organic wastewater includes a dryer (18) as a means of producing dried feed by drying sludge, etc.

[0056] The above dryer (18) is a dryer that dries sludge produced during the process of dewatering food waste using steam as a heat source. This dryer (18) can dry sludge using high-temperature steam supplied from the deodorizing incineration boiler (26) or the auxiliary boiler (not shown) as a heat source. The dried material discharged from the dryer (18) can be used as dried feed, compost, solid fuel, etc. after undergoing crushing and sorting processes.

[0057] And, the waste gas discharged from the above dryer (18) passes through a cyclone (not shown), a trap (not shown), etc., and in this process, foreign substances and oil in the waste gas are filtered out, and the waste gas is continuously sent to a condenser (15).

[0058] In addition, the above condenser (15) serves as a means for condensing waste gas, and condenses high-temperature waste gas using low-temperature circulating water. The waste gas discharged from the condenser (15) is sent to a deodorizing incineration boiler (26) for incineration treatment, and after the odors are removed, it passes through a stack (27) and is released into the atmosphere.

[0059] At this time, the low-concentration condensed wastewater discharged from the condenser (15) is sent to and stored in the condensed wastewater storage tank (16).

[0060] In addition, the food waste treatment system utilizing the above-mentioned high-concentration organic food waste includes a mixing tank (12) that produces high-concentration organic food waste by mixing the digested water discharged from the #1 digester (11) and the sludge discharged from the low-speed, three-phase separator (10).

[0061] The above mixing tank (12) receives the digested water discharged from the #1 digester (11) and the sludge discharged from the low-speed, three-phase separator (10), and then mixes the digested water and sludge appropriately with its own agitator (27) to produce high-concentration organic wastewater.

[0062] And, a high-concentration organic food waste storage tank (14) is connected and installed at the rear end of the mixing tank (12), and accordingly, the high-concentration organic food waste discharged from the mixing tank (12) is stored in the high-concentration organic food waste storage tank (14), and then mixed more uniformly there by an underwater motor stirrer (13).

[0063] The high-concentration organic wastewater produced in the mixing tank (12) is sent to the high-concentration organic wastewater storage tank (14) for storage, and some of the high-concentration organic wastewater supplied from the high-concentration organic wastewater storage tank (14) is supplied to a consumption site that requires high-concentration organic wastewater, such as a wastewater treatment plant, while most of the remainder is supplied to the #2 digestion tank (28) for digestion treatment.

[0064] In particular, the high-concentration organic wastewater produced in the mixing tank (12) is sent to the high-concentration organic wastewater storage tank (14) for storage, and then most of the high-concentration organic wastewater supplied from the high-concentration organic wastewater storage tank (14) is sent to the #2 digester (28) for full treatment, thereby reducing the amount of sludge and increasing the production of biogas.

[0065] Of course, in the case of distributing high-concentration organic food waste, appropriate distribution of high-concentration organic food waste can be achieved manually or automatically by means of a flow control valve (not shown) installed at the branching point of each line.

[0066] As a preferred embodiment, the food waste treatment system utilizing the high-concentration organic wastewater includes a condenser (15) that condenses waste gas, i.e., waste gas discharged from a dryer (18), after drying the food waste, and a condensed wastewater storage tank (16) that stores low-concentration condensed wastewater discharged from the condenser (15).

[0067] And, the low-concentration condensed wastewater discharged from the above-mentioned condensed wastewater storage tank (16) is treated at its own wastewater treatment plant or supplied to a consumer that requires it.

[0068] In addition, the food waste treatment system utilizing the above-mentioned high-concentration organic wastewater includes an intermediate storage hopper (17) for storing sludge produced after dewatering food waste, i.e., sludge discharged from a dewatering machine (21), and sludge produced after extracting oil, i.e., sludge discharged from a low-speed, three-phase separator (10).

[0069] Accordingly, in the intermediate storage hopper (17), the sludge supplied from the low-speed, three-phase separator (10) and the sludge supplied from the dewatering machine (21) are mixed, and the mixed sludge is fed into the dryer (18) and dried.

[0070] In addition, the food waste treatment system utilizing the above-mentioned high-concentration organic food waste includes a #2 dryer (28) as a means to produce biogas by digesting the high-concentration organic food waste made by mixing sludge and digested water.

[0071] The above #2 digester (28) is a medium-temperature digester in which the internal temperature is maintained at approximately 38 to 42°C. When high-concentration organic wastewater is introduced into the #2 digester (28), the high-concentration organic wastewater is retained and fermented within the digester for a predetermined period of time. The biogas generated through this retention and fermentation process is collected at the top of the digester, the digested water (filtrate) is collected at the upper layer of the water level within the digester, and the heavy digested sludge is collected at the lower layer of the digester.

[0072] Here, the biogas in the #2 digester (28) can be used for itself after undergoing a predetermined treatment process, sold after undergoing an electricity production process, or sold as city gas fuel after undergoing a purification process.

[0073] And, the digested water and sludge discharged from the above #2 digester (28) are sent to the aging tank (24b), and the digested water and sludge sent to the aging tank (24b) are retained in the aging tank (24b) for a while and are circulated with the #2 digester (28) to undergo a fermentation aging process and a solid-liquid separation process.

[0074] In addition, the digested water (supernatant) discharged from the aging tank (24b) is sent to the digested water storage tank (25) for storage, and the sludge discharged from the aging tank (24b) is sent to the dryer (18) for drying treatment or can be entrusted to an external facility for treatment.

[0075] At this time, the digestion water discharged from the digestion water storage tank (25) is distributed in appropriate proportions, some of which is entrusted to an external treatment facility, and the remainder is supplied to the mixing tank (12).

[0076] Of course, in the case of distributing the treated water, the appropriate distribution of the treated water can be achieved manually or automatically by means of a flow control valve (not shown) installed at the branching point of each line.

[0077] Therefore, the overall process of the food waste treatment system utilizing high-concentration organic wastewater configured in this manner is as follows.

[0078] As illustrated in FIG. 1, food waste brought in from the outside is sent to a low-speed, three-phase separator (10) via a raw material hopper (19) → crusher (20) → dehydrator (21) → food waste storage tank (22a).

[0079] In the above low-speed, three-phase separator (10), oil is extracted from the wastewater, and the oil is subsequently purified and shipped for sale, and the sludge is sent to the mixing tank (12) and intermediate storage hopper (17), and the wastewater is stored in the wastewater storage tank (22b), then passes through the mixing adjustment tank (23) and is sent to the #1 digestion tank (11).

[0080] In the above #1 digester (11), anaerobic digestion of the wastewater is performed, and subsequently, the biogas is purified and shipped for sale. The wastewater and digested sludge are repeatedly circulated with the maturation tank (24a), and then the supernatant is sent to the digested water storage tank (25) for storage. The digested sludge, etc., are sent to a dryer (18) for drying treatment (not shown in the drawing), or are entrusted to an external facility for treatment, or sent to a consumption site such as a wastewater treatment plant.

[0081] In particular, the digested water discharged from the above digested water storage tank (25) is supplied to the mixing tank (12), and at the same time, the sludge discharged from the low-speed, three-phase separator (10) is also supplied to the mixing tank (12), and at this time, the digested water and sludge are mixed in the mixing tank (12) to produce high-concentration organic wastewater.

[0082] Subsequently, the high-concentration organic wastewater produced in the mixing tank (12) is stored in the high-concentration organic wastewater storage tank (14). Then, some of the high-concentration organic wastewater produced in this way is supplied to a consumption site that requires high-concentration organic wastewater, such as a wastewater treatment plant, and consumed, while the remainder is supplied to the #2 digestion tank (28) for digestion treatment.

[0083] And, in the above #2 digester (28), anaerobic digestion of the wastewater is carried out, and subsequently, the biogas is purified and shipped out for sale. The wastewater and digested sludge are repeatedly circulated with the maturation tank (24b), and then the supernatant is sent to the digested water storage tank (25) for storage. The digested sludge, etc., are sent to a dryer (18) for drying treatment (not shown in the drawing), or are entrusted to an external facility for treatment, or are sent to a consumption site such as a wastewater treatment plant.

[0084] In this way, the present invention provides a system for treating food waste by utilizing high-concentration organic food waste leachate produced by mixing the digested water discharged after anaerobic digestion treatment and the sludge discharged after oil separation, thereby enabling sufficient supply of high-concentration organic food waste leachate to consumption sites such as wastewater treatment plants, reducing energy costs by increasing biogas production, and smoothly supplying mixed wastewater containing organic matter of appropriate standards to consumption sites that require it. Explanation of the symbols

[0086] 10: Low speed, three-phase separator 11 : #1 Digester 12: Mixing tank 13 : Submersible motor stirrer 14: High-concentration organic food waste storage tank 15 : Condenser 16 : Condensed wastewater storage tank 17: Intermediate storage hopper 18 : Dryer 19 : Raw Material Hopper 20 : Shredder 21 : Dehydrator 22a, 22b : Food waste storage tanks 23: Mixing Adjustment Unit 24a, 24b: Aging tank 25 : Digested water storage tank 26 : Deodorizing Incineration Boiler 27 : Stirrer 28 : #2 Digester

Claims

Claim 1 A food waste treatment system utilizing high-concentration organic food waste, comprising: a low-speed, three-phase separator (10) for separating oil from food waste leachate after dewatering food waste; a #1 digester (11) for digesting food waste leachate supplied from the low-speed, three-phase separator (10); and a mixing tank (12) for producing high-concentration organic food waste leachate by mixing the digested water discharged from the #1 digester (11) and the sludge discharged from the low-speed, three-phase separator (10); wherein the high-concentration organic food waste leachate produced in the mixing tank (12) is supplied to a consumption site requiring high-concentration organic food waste leachate and / or supplied to a #2 digester (28) for digestion treatment, and a portion of the sludge discharged from the low-speed, three-phase separator (10) is sent to a mixing adjustment tank (23) and then supplied to the #1 digester (11) to be used for preserving organic matter concentration and replenishing flow rate. Claim 2 A food waste treatment system utilizing high-concentration organic food waste according to claim 1, further comprising a high-concentration organic food waste storage tank (14) installed at the rear end of the mixing tank (12) and storing the high-concentration organic food waste discharged from the mixing tank (12) and uniformly mixing it using an underwater motor stirrer (13). Claim 3 delete Claim 4 A food waste treatment system utilizing high-concentration organic wastewater according to claim 1, comprising an intermediate storage hopper (17) for storing sludge produced after dewatering food waste, wherein a portion of the sludge discharged from the low-speed, three-phase separator (10) is supplied to the intermediate storage hopper (17), mixed with the sludge in the intermediate storage hopper (17), and then fed into a dryer (18) for drying treatment.

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