Oil and sludge collection tank

Abstract

To provide an oil and sludge recovery tank which can be installed on-site in a food factory or the like which discharges oil-containing wastewater and can recover oil and sludge from the oil-containing wastewater while minimizing the need for work requiring opening a lid, which is a cause of foul odor. [Solution] The oil and sludge recovery tank is equipped with an oil removal valve OV provided on the bottom side of its side, a waste solids removal body 4 which has a U-shape when viewed from above and is composed of three rectangular pillar-shaped waste solids removal plates 4a-4c erected from the bottom of the oil and sludge recovery tank, and a suction space AS which is a space surrounded by the side and the waste solids removal body 4 and is used to suck up oil stored in the oil and sludge recovery tank via the oil removal valve OV.

Description

[Technical field]

[0001] The present invention relates to an oil and sludge recovery tank for recovering oil and sludge that can be reused as an energy source from oil-containing wastewater, which is a biomass resource discharged from food factories and commercial facilities. [Background technology]

[0002] Wastewater from food factories and other manufacturing plants contains various water pollutants (oils). If such wastewater is discharged without any treatment, the oils in the wastewater will adhere to and solidify in drainage pipes, causing blockages. As a result, it becomes difficult to purify the water in combined treatment tanks and sewage treatment plants, and it can have a negative impact on the environment and lead to legal restrictions that may make it impossible to continue business. For this reason, various methods and devices have been proposed for treating wastewater containing solids such as oils, sediments, and suspended matter at the individual business facility where it is discharged.

[0003] One such method is to pool oil-containing wastewater in a large tank such as an oil-water separator or raw water tank, periodically pump out the large amount of floating oil that rises to the top, and adsorb it with an adsorbent and filter it, thereby physically removing the oil and other substances from the wastewater.

[0004] On the other hand, wastewater from commercial facilities such as restaurants, fast food outlets, restaurants, and hotels also contains various water pollutants. If such wastewater is discharged without any treatment, the oil and other substances in the wastewater will adhere to and solidify in drainage pipes, causing blockages, and also making it difficult to purify the water in combined treatment tanks and sewage treatment plants, and also having a negative impact on the environment. Therefore, business establishments that discharge wastewater containing solids such as oil, sediment, and suspended matter are equipped with treatment equipment (grease traps, oil-water separators, raw water tanks) on a business-by-business basis, temporarily pooling the wastewater, allowing the solids to settle and the oil to float and separate, and periodically removing and treating these substances to physically remove them.

[0005] Incidentally, for example, a simple device has been disclosed that selectively separates and removes waste solids contained in waste oil once collected from small-scale businesses that discharge waste oil and waste solid-containing wastewater, and transfers only the waste oil to a separate transport and storage container (see, for example, Patent Document 1). Also disclosed is an oil and sludge recovery tank for more efficiently recovering oil and sludge from the upper layer of an oil-water separation tank that pools oil-containing wastewater (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 5452814 [Patent Document 2] Patent No. 7255941 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the above-mentioned methods and devices for temporarily pooling oil-containing wastewater in large tanks such as oil-water separators and periodically pumping it out for treatment, and the methods and devices for drawing it out from grease traps and the like, require operations to be carried out with the lid of the device open, which results in the generation of foul odors from the wastewater during operations, causing problems.

[0008] In addition, in the above conventional methods, the labor burden of manually collecting sludge remaining in large tanks such as oil-water separators and grease traps is still incurred periodically. For this reason, a device or tank that automatically collects oil and sludge that can be reused as an energy source from oil-containing wastewater without the need for manual work of opening the lid has not yet been realized.

[0009] Furthermore, the oil recovered from the oil-water separation tank or grease trap has excess garbage and the like removed in a refinement and transfer device before being stored in a refined oil tank, etc. However, at the site where the oil and sludge are recovered, the refinement and transfer device must be set up and cleaned up, which creates a problem of workload.

[0010] Furthermore, in recent years, the problem of global warming has become more serious, and renewable energy that reuses waste materials has attracted attention. The amount of wastewater and oils, which are biomass resources discharged from food factories and other sources, is more than 300,000 tons per year throughout Japan, and the amount is even greater when considering the entire world. For this reason, there is an urgent need to establish equipment and technology that can efficiently and automatically recover recyclable oil from wastewater and oils discharged from food factories and other sources.

[0011] The present invention has been made in consideration of the above problems, and aims to provide an oil and sludge recovery tank that can be installed on-site at food factories, commercial facilities, etc. that discharge oil-containing wastewater and can recover oil and sludge from oil-containing wastewater while minimizing the need to open the lid, which is a cause of foul odors. Another aim of the present invention is to provide an oil recovery system that utilizes this oil and sludge recovery tank. [Means for solving the problem]

[0012] In order to achieve the above-mentioned object, the present invention provides an oil and sludge recovery tank for recovering reusable oil and sludge from oil-containing wastewater, the oil and sludge recovery tank comprising an oil removal valve provided on the bottom side of a side of the oil and sludge recovery tank, a waste solid removal body erected from the bottom of the oil and sludge recovery tank, and a suction space surrounded by the side and the waste solid removal body for sucking up oil stored in the oil and sludge recovery tank via the oil removal valve, the waste solid removal body having an oil selection function that selectively passes oil through.

[0013] In this oil and sludge recovery tank, it is preferable that the waste solid removal body has a U-shape when viewed from above and is composed of three rectangular prism-shaped waste solid removal plates erected from the bottom surface of the oil and sludge recovery tank.

[0014] In this oil and sludge recovery tank, as the oil selection function, it is preferable that a plurality of punched holes are formed on the surface of the waste solid removal body, the internal space of the waste solid removal body is filled with glass wool, and a thin plate is disposed on the bottom side of the waste solid removal body to act as a wall to prevent water from being pressed in.

[0015] In this oil and sludge recovery tank, it is preferable to provide a cover for covering the suction space and the waste solid remover from the outside.

[0016] In this oil and sludge recovery tank, it is preferable that the cover device has three sides and the top formed with plate-shaped intrusion prevention walls, one side and the bottom are open, and a slide bar extending vertically is connected to the top surface of the cover device.

[0017] In this oil and sludge collection tank, it is preferable that the oil and sludge collection tank further includes a detachable cover plate which maintains an airtight state with the oil and sludge collection tank when in a closed state, and that the slide bar of the cover device penetrates a through hole formed in the cover plate and is slidable in the vertical direction.

[0018] In this oil and sludge recovery tank, it is preferable that a float plate is integrally provided on the upper surface of the cover.

[0019] In this oil and sludge recovery tank, the oil and sludge recovery tank has an approximately rectangular parallelepiped shape, and is provided at its bottom with a water discharge valve for discharging water and a sludge discharge valve for removing sludge, and it is preferable that at least one of its side and bottom is provided with a tank heating section arranged in a planar shape for heating the oil and sludge recovery tank.

[0020] In order to achieve the above object, the present invention provides an oil recovery system, which is a system for recovering oil and sludge from an oil supply pipe that delivers the upper layer from an oil-water separation tank through an oil and sludge recovery tank. water The system is characterized by having a circulation pipe returning to the separation tank, and an oil and sludge recovery tank for recovering oil and sludge from the oil-water separation tank.

[0021] In order to achieve the above-mentioned object, the present invention provides an oil recovery system comprising an oil and sludge recovery tank, the oil and sludge recovery tank further comprising a water / residue recovery valve provided on the bottom of the oil and sludge recovery tank for recovering residue and water separated at the bottom, and the oil recovery system is characterized in having a water / residue tank connected to the water / residue recovery valve for storing water and residue extracted from the water / residue recovery valve.

[0022] In this oil recovery system, it is preferable that the water / residue tank further includes a detachable cover plate that maintains a sealed state between the water / residue tank and the water / residue tank in a closed state. Effect of the Invention

[0023] The present invention is an oil and sludge recovery tank for recovering reusable oil and sludge from oil-containing wastewater, comprising an oil removal valve provided on the bottom side of the side of the oil and sludge recovery tank, a waste solid remover erected from the bottom of the oil and sludge recovery tank, and a suction space surrounded by the side and the waste solid remover for sucking the oil stored in the oil and sludge recovery tank through the oil removal valve, the waste solid remover having an oil selection function for selectively passing oil. With this configuration, the present invention can be installed on-site in food factories and commercial facilities that discharge oil-containing wastewater, and can recover oil and sludge from oil-containing wastewater while minimizing the work of opening the lid, which causes odors. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is a diagram illustrating an overview of an oil recovery system including an oil and sludge recovery tank according to a first embodiment of the present invention. [Diagram 2] (a) is a bottom view of the oil and sludge recovery tank, (b) is a side view of the oil and sludge recovery tank, (c) is an enlarged plan view of an oil selective separation mechanism provided in the oil and sludge recovery tank, and (d) is a side view of the oil and sludge recovery tank. [Diagram 3] 4(a) to 4(d) are explanatory diagrams of a cover plate provided on the oil and sludge recovery tank. [Figure 4] (a) is a plan view of the waste solids removal plate installed in the oil and sludge recovery tank, and (b) is an explanatory diagram of the waste solids removal plate and suction space. [Diagram 5] 4(a) and (b) are explanatory diagrams of a cover device provided on the oil and sludge recovery tank. [Figure 6] 5(a) and 5(b) are diagrams illustrating a method of using the same covering device. [Figure 7] A functional block diagram of the oil and sludge collection tank is shown. [Figure 8] 13(a) and 13(b) are diagrams showing the transition state of the stored amounts in the oil and sludge recovery tanks. [Figure 9] 4(c) and (d) are diagrams showing the transition state of the stored amounts in the oil and sludge recovery tanks. [Figure 10] FIG. 11 is a diagram illustrating an overview of an oil recovery system including an oil and sludge recovery tank and a water / residue recovery tank according to a second embodiment of the present invention. [Figure 11] (a) is a bottom view of the water and residue recovery tank, (b) is a side view of the water and residue recovery tank, and (c) is a side view of the water and residue recovery tank. [Figure 12] 4(a) to 4(d) are explanatory diagrams of a cover plate provided on the oil and sludge recovery tank. [Figure 13] 13(a) and 13(b) are diagrams showing the transition state of the stored amounts in the oil and sludge recovery tanks. [Figure 14]4(c) and (d) are diagrams showing the transition state of the stored amounts in the oil and sludge recovery tanks. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] (Embodiment 1) An oil recovery system including an oil and sludge recovery tank according to a first embodiment of the present invention will be described with reference to Figs. 1 to 9. This oil and sludge recovery tank is a tank that pumps out and temporarily stores a large amount of the upper layer (floating oil and fat) floating in an oil-water separation tank (raw water tank) that pools manufacturing wastewater discharged from a food factory or the like. The upper layer of the oil-water separation tank contains water, sludge, and oil in order of decreasing specific gravity. This oil recovery system efficiently recovers oil and sludge from the floating oil and fat pumped out of the oil-water separation tank to reuse (resource) energy, and is a food factory on-site resource recovery type that is installed on-site in a food factory that discharges manufacturing wastewater.

[0026] First, an oil recovery system S equipped with an oil and sludge recovery tank (hereinafter referred to as a recovery tank) according to the present embodiment 1 will be described with reference to Fig. 1. The oil recovery system S includes an oil-water separation tank OS and a recovery tank T. The oil-water separation tank OS is also called a grease trap, oil trap, grease interceptor, etc., and generally has a basic structure of a natural separation and flotation method that utilizes the difference in specific gravity between water and oil.

[0027] The piping of the oil recovery system S includes an inlet pipe P1 (oil supply path (corresponding to arrow A)) for sending the floating oil (upper layer) in the oil-water separation tank OS to the recovery tank T, and a circulation pipe P2 (return path (corresponding to arrow B)) for returning the influent stored in the recovery tank T to the oil-water separation tank OS. The function of performing the circulation operation shown in this diagram makes it possible to efficiently recover oil and sludge in the recovery tank T, and to circulate the influent to return it to the oil-water separation tank OS. Pumps are provided in the inlet pipe P1 and the circulation pipe P2.

[0028] The recovery tank T receives floating oil (upper layer) from the oil-water separation tank OS, which temporarily stores oil-containing wastewater, via an inlet pipe P1. The recovery tank T also has an inlet valve 11 that controls the inflow rate of the floating oil pumped from the oil-water separation tank OS via the inlet pipe P1. Oil water, sludge, and water flow into the recovery tank T from the oil-water separation tank OS.

[0029] An oil removal valve OV, such as a 25A HT ball valve, for exclusive oil recovery is provided on the side of the recovery tank T (the lower right side in FIG. 1). The oil removal valve OV is fixed horizontally, for example, so that the lower end of its cylindrical shape is located 3 cm above the bottom surface of the recovery tank T. Then, via a pump such as an electromagnetic pump, the oil recovered through the oil removal valve OV flows into a purification and transfer device 12 for separating excess solids contained in the oil.

[0030] The recovery tank T is, for example, 1500 mm wide x 1100 mm deep x 570 to 650 mm high (1200 mm high when the support 2 is included) (approximate capacity 1000 L), and has a roughly rectangular parallelepiped shape with a gentle slope downward to one side on the bottom so that excess garbage does not accumulate inside. Note that the shape of the recovery tank T is not limited to the shape shown in this figure, and other shapes such as a cylindrical shape may be used as long as the same function is achieved.

[0031] The refined transfer device 12 has a centrifugal separation function such as Filstar (registered trademark), and after excess solids other than oil are collected in a train cup, the clean refined oil from which the excess solids have been removed is finally collected in a refined oil tank (e.g., a 1000L IBC container) 13.

[0032] A water discharge valve WV, such as a 40A motorized ball valve, is provided on the bottom of the recovery tank T to recover moisture, and the discharged moisture is returned as wastewater to the oil-water separation tank OS via the circulation pipe P2. At this time, a discharge valve 14 may be provided to control the amount of water discharged. The inlet valve 11 and the discharge valve 14 are, for example, motorized valves, and the opening and closing states of the valves are controlled in response to command signals from a control unit, which will be described later. The oil removal valve OV and the water discharge valve WV may be either motorized valves or manual ball valves that are opened and closed manually without receiving a command signal.

[0033] In addition, a sludge discharge valve DV for exclusively removing sludge is provided on the bottom side surface of the recovery tank T, and the sludge stored in the recovery tank T is removed. The removed sludge is separated by a sludge removal device 15, and the separated sludge is collected in a sludge tank 16.

[0034] In order to support the recovery tank T in a hollow state, the recovery tank T is provided with vertically extending supports 2 at the four corners on the bottom side. These supports 2 make the top surface height of the recovery tank T, for example, 1200 mm, making it easier for workers to recover the oil and sludge.

[0035] As shown in Fig. 3, three plate-shaped cover plates 3 are removably provided on the top surface of the recovery tank T. As shown in Fig. 3, the cover plates 3 are fixed at the four corners thereof by means of a knob bolt 33 via a packing 32 so as to be able to be opened and closed. The cover plates 3 usually keep the recovery tank T sealed so that odors and the like are not released to the outside. On the other hand, the cover plates 3 can be removed by removing the knob bolts 33 as necessary, so that the inside of the recovery tank T can be cleaned or the inside of the recovery tank T can be visually inspected. Note that although the shape of the cover plates 3 is rectangular in this drawing, they may be other shapes such as square or circular.

[0036] The recovery tank T is equipped with a tank heating section H such as a planar silicon rubber heater (three-phase 200V) made of a nickel alloy sandwiched between silicon rubber sheets that heats the bottom and the front, back, left and right sides of the tank, a temperature sensor TS that detects the temperature inside the recovery tank T, and an oil detection sensor ODS that detects oil on the bottom of the recovery tank T.

[0037] The tank heating unit H is provided in a planar shape along five surfaces, for example the sides and bottom of the recovery tank T, and the heating unit can be turned on or off by selecting the sides and bottom. The temperature sensor TS is a temperature sensor that measures the temperature of the stored contents in the recovery tank T by utilizing the fact that the electrical resistance of a semiconductor or the like changes with temperature. The oil detection sensor ODS is a sensor that detects the presence of oil at a specified position (for example the bottom side) of the recovery tank T, and uses, for example, an optical fiber to detect the output change caused by the propagating light being attenuated by being scattered to the outside when oil adheres to it or being absorbed by the oil.

[0038] A SUS (stainless steel) waterproof cover is attached to the surface side of the tank heating section H using packing and screws, and a heat insulating material is sealed inside. By sealing the heat insulating material in this way, the temperature inside the recovery tank T can be maintained in the range of about 65 to 70 degrees for a long period of time, which promotes efficient separation of the oil, sludge, and water inside the recovery tank T.

[0039] Recovery tank T is equipped with a float sensor FS, which is a level gauge capable of detecting the interface between the water layer and the oil mud layer (a mixture of oil and sludge) inside it. This float sensor FS is a measuring instrument that uses the fact that a float moves up and down due to the weight of the oil mud to measure the interface between the water layer and the oil mud layer stored in recovery tank T, and serves to accurately measure the interface between the water layer and the oil mud layer inside recovery tank T. This float sensor FS can detect the approximate amount of oil and sludge inside recovery tank T.

[0040] Next, the oil selective separation mechanism S1 provided inside the recovery tank T according to the first embodiment will be described with reference to Fig. 4 to Fig. 6. As shown in Fig. 4, the recovery tank T has three rectangular prism-shaped waste solid content removal plates 4a to 4c arranged in series and a waste solid content remover 4 having a U-shape in top view standing upright from the bottom. The waste solid content remover 4 and the side surface on which the oil removal valve OV is formed form an oil suction space AS. The waste solid content remover 4 is not limited to a U-shape in top view, and may be another shape such as a semicircular shape in top view as long as it has the function.

[0041] The waste solid remover 4 is erected at a predetermined height (e.g., 250 mm) from the bottom surface of the recovery tank T and has a size of, for example, about 500 mm long side × 350 mm short side when viewed from above. The suction space AS has a size of about 300 mm long side × 250 mm short side × 250 mm high (for example, a capacity of 18.75 L).

[0042] This waste solid content remover 4 (as well as the three waste solid content removal plates 4a-4c) has an oil selection function. It has a mesh structure made of metal or synthetic resin (for example, glass wool or stainless steel punching) that can filter and remove waste solid content such as dirt and floating matter. Specifically, as an oil selection function, a plurality of punching holes 42 are formed on the surface of the waste solid content remover 4, and the internal space is filled with glass wool 43 as a filler. However, this shape may be other structures or shapes as long as it can selectively suck up oil.

[0043] Also, as shown in Fig. 4(b), a thin plate 41 made of stainless steel (SUS) may be welded to about 50 mm from the lower side of the waste solid removal body 4 to prevent water from being pressed in. This thin plate 41 prevents water from flowing into the suction space AS even if water remains at the bottom of the recovery tank T and the waste solid removal body 4 is subjected to water pressure from the outside, and thus prevents water from flowing into the suction space AS. Assuming that water will flow into the suction space AS, it may be possible to provide a water discharge valve WV and an oil detection sensor on the bottom side of the suction space AS to discharge the water that flows into the suction space AS.

[0044] 5, the recovery tank T further includes a cover 5 for covering the suction space AS formed by the waste solid removal body 4 and the waste solid removal body 4 from the outside. The cover 5 has a rectangular parallelepiped shape with three side surfaces and the top surface formed by plate-shaped intrusion prevention walls 51 and one side surface and the bottom surface open, and a vertically extending slide bar 52 is connected to the top surface of the cover 5. The slide bar 52 penetrates through a through hole 32 formed in the cover plate 3 of the recovery tank T, allowing the cover 5 to slide up and down. The cover 5 has a shape that covers the waste solid removal body 4 (i.e., the suction space AS) from the outside when positioned at the lowest position.

[0045] 5(b), a float plate 53 may be integrally provided on the upper surface of the covering device 5. This configuration of the float plate 53 allows the covering device 5 to move up and down without coming off the float plate 53, and prevents the covering device 5 from sinking due to the weight of oil or the like that has flowed into the inside of the recovery tank T. Specifically, the float plate 53 is a polystyrene foam plate in the present embodiment 1.

[0046] Next, a method of using the cover device 5 will be described with reference to Fig. 6. First, when the floating oil and fat flows in from the oil-water separation tank OS and when the tank heating section H of the collection tank T is used for heating, the cover device 5 is slid to the bottom end so as to cover the outer periphery of the waste solid content removal body 4, as shown in Fig. 6(a). This prevents sludge from adhering to the waste solid content removal body 4, and appropriately prevents the waste solid content removal body 4 from becoming dirty and reducing the oil recovery efficiency.

[0047] On the other hand, as shown in Fig. 6(b), when recovering oil from the oil removal valve OV, the slide bar 52 is used to slide the cover 5 upward so that the oil comes into contact with the waste solid removal body 4 (i.e., so that the oil can enter the suction space AS). This causes the waste solid removal body 4 to come into contact with the oil stored in the recovery tank T, or allows the oil to flow in from the upper surface side of the suction space AS.

[0048] Next, the function of an ECU (Electronic Control Unit) 31 provided in a control panel provided in the recovery tank T will be described with reference to Fig. 7. Note that the control panel is not an essential component of the recovery tank T according to the first embodiment. The control panel may be integrally provided in the recovery tank T, or may be separate from the recovery tank T.

[0049] The ECU 31 opens the inflow valve 11 to allow the oil-containing wastewater from the oil-water separation tank OS to flow into the recovery tank T. The ECU 31 also controls the tank heating unit H to start heating operation when the inflow valve 11 is closed. The ECU 31 also controls the tank heating unit H to stop heating operation when the temperature detected by the temperature sensor TS reaches a predetermined temperature (65-70 degrees). In this way, the tank heating unit H is controlled to repeatedly operate on and off.

[0050] Thereafter, the ECU 31 controls the water discharge valve WV to open, so that only the water can be efficiently returned from the recovery tank T to the oil-water separation tank OS.

[0051] After that, when the oil detection sensor ODS installed on the bottom surface of the recovery tank T detects oil, the ECU 31 manually / electrically slides the cover 5 upward and then opens the oil extraction valve OV. This allows only the oil to be efficiently sent from the recovery tank T to the refinement and transfer device 12.

[0052] Specifically, the ECU 31 includes a control unit 31a, a predetermined amount calculation unit 31b, a signal transmission unit 31c, and an input unit 31d, as shown in Fig. 7. In order to efficiently separate the floating grease filled in the recovery tank T into oil, sludge, and water by heating the grease, the control unit 31a determines whether or not it is necessary to receive an oil detection signal from the oil detection sensor OS, and when it receives an oil detection signal, it transmits a control signal to start operation to the tank heating unit H via the signal transmission unit 31c.

[0053] The predetermined amount calculation unit 31b performs calculation processing of a predetermined value based on various parameter information (the capacity of the recovery tank T, the inflow amount from the inlet valve 11, the discharge amount from the discharge valve 14, the temperature of TS, and oil detection). The signal transmission unit 31c transmits an on / off control signal for the heating operation to the tank heating unit H. It also transmits a valve opening adjustment signal to the inlet valve 11 and the discharge valve 14. The input unit 31d provided on the control panel is an operation setting device, a remote control, or the like, and enables input of various parameter information required for the calculation of the predetermined amount in the predetermined amount calculation unit 31b, and also enables input setting of the predetermined amount.

[0054] Next, the transition state of the stored contents in the recovery tank T according to the first embodiment will be described with reference to Figures 8 and 9. First, floating oil and grease is flowed into the recovery tank T from the oil-water separation tank OS, and when the liquid level detected by the float sensor FS or the like reaches a predetermined position, the inlet valve 11 is closed. This flow path switching may be performed manually. At this time, the cover device 5 is fixed in position at the lowest position.

[0055] Next, the tank heating section H is started to heat the inflow until it reaches about 70 degrees. When it reaches about 70 degrees, the inflowing oil is separated in order of specific gravity, and the floating oil that has flowed in is separated from the bottom into a layer of water, oil-containing floating sludge (so-called black oil), and oil, as shown in Figure 8(a).

[0056] Then, when the temperature sensor TS provided on the tank body reaches, for example, 70 degrees and the heating of the wastewater is completed (i.e., separation into each layer is completed), the water discharge valve WV formed on the bottom of the recovery tank T is opened, and the water at the bottom side of the recovery tank T is returned to the oil-water separation tank OS via the discharge valve 14. Then, when the removal of the inflow water is completed, sludge (oil-containing floating sludge) and oil are stored in the recovery tank T from the lower layer, as shown in Figure 8 (b). This sludge may be manually collected via the sludge discharge valve (manual valve) DV formed on the bottom side of the recovery tank T as shown in Figure 8 (b).

[0057] The oil-containing floating sludge that is extracted is classified as industrial waste, so it can be stored in a sludge industrial waste tank and treated as industrial waste sludge. This sludge can be used, for example, for biogasification (methane power generation, clean hydrogen), and the first step in turning this unused sludge into a resource is expected to be biogasification (methane power generation, green hydrogen) in a biogas plant that performs methane fermentation.

[0058] When the sludge layer is discharged, the oil falls and accumulates, but when the oil falls to the bottom of the recovery tank T, the recovery tank T enters the state shown in Figure 9(c), and the oil is detected by the oil sensor OS. Then, the oil purification / transfer lamp lights up, and the worker closes the sludge discharge valve (manual valve) DV. The sludge discharge valve (manual valve) DV may be controlled to close automatically.

[0059] Then, when oil is stored in the recovery tank T as shown in Figure 9(c), the worker releases the cover device 5, and the upper surface of the cover device 5 automatically floats up to above the oil due to the action of the float plate 53. Alternatively, the worker may slide the cover device 5 upward to a height of about 350 mm of the waste solid removal body 4, or even higher, so that a gap is created between the upper surface of the suction space AS and the bottom surface of the cover device 5. After that, the oil removal valve OV is opened, and the electric pump is turned on.

[0060] Then, the oil in the recovery tank T is automatically recovered, and the inside of the recovery tank T transitions to the state shown in Fig. 9(d). The recovered oil is purified by the refinement and transfer device 12 to remove fine debris, and is then recovered in the refined oil tank 13.

[0061] In the past, for example, a purification and transfer device, which is a waste solids, waste oil impurities, and waste water layer separator as shown in Patent No. 5452814, was introduced into a tank from above with the lid opened each time, to selectively separate and remove the waste solids, waste oil impurities, waste water, etc. contained in the waste oil, and only the waste oil usable as an alternative fuel to petroleum was transferred to a separate container for transportation and storage. On the other hand, in the present invention, there is no need to open the lid plate 3 of the recovery tank T each time and introduce the purification and transfer device that efficiently recovers only the oil layer in the recovery tank T, which improves work efficiency and greatly reduces the frequency of opening the lid, making it less likely to produce odors.

[0062] In this manner, the oil, sludge, and water in the recovery tank T are separated, completing a series of recovery operations. After this, when the capacity of the oil-water separation tank OS installed in the same facility becomes full, the steps from (a) to (d) in Figure 8 are repeated, and the oil is moved to the recovery tank T, and the separation and recovery of the oil and sludge is automatically and efficiently repeated.

[0063] As described above, the present invention relates to an oil and sludge recovery tank T for recovering reusable oil and sludge from oil-containing wastewater, the oil and sludge recovery tank T comprising an oil removal valve OV provided on the bottom side of the side of the oil and sludge recovery tank T, a waste solid removal body 4 having a U-shape when viewed from above and consisting of three rectangular prism-shaped waste solid removal plates 4a-4c erected from the bottom of the oil and sludge recovery tank T, and a suction space AS surrounded by the side and the waste solid removal body 4 for sucking up oil stored in the oil and sludge recovery tank T via the oil removal valve OV, and the waste solid removal body 4 has an oil selection function that selectively passes oil.

[0064] With this configuration, in the recovery tank T according to this embodiment, (1) the oil recovery (recycling) work from the wastewater oils and fats can be performed with almost no opening of the cover plate 3, and odors are unlikely to be generated. (2) By simply installing the recovery tank T on-site in the facility, the oil refining and transfer and sludge removal can be nearly automated, eliminating the burden of manual work by workers each time, and recycling of the wastewater oils and fats can be completed.

[0065] In other words, the recovery tank T is installed on-site in an energy-saving and space-saving manner in a food factory or the like that discharges oil-containing wastewater, and can extract, recover, and recycle oil and sludge from the oil-water separation tank OS that pools the oil-containing wastewater almost automatically while preventing the generation of odor. Also, some food factories generate several tons of floating oil and fat every day, and by installing an on-site type facility such as the recovery tank T of the present invention on the factory premises, it is possible to provide an on-site resource recovery service.

[0066] Furthermore, the sludge can be extracted and efficiently recovered through the sludge discharge valve (manual valve) DV installed in the recovery tank T. Furthermore, the inflow water that flows into the recovery tank T can be returned directly to the oil-water separation tank OS through the circulation pipe P2.

[0067] (Embodiment 2) Next, an oil recovery system according to a second embodiment of the present invention will be described with reference to Fig. 10 to Fig. 14. This oil recovery system S2 is used in commercial facilities, restaurants such as fast food chains, and fuel manufacturing plants that discharge wastewater containing solids such as oil, sediment, and suspended matter. The oil and sludge recovery tank T according to the second embodiment also serves as a tank for temporarily storing floating oil and sludge pooled in a treatment device (e.g., a grease trap) that has been conventionally provided at each business establishment.

[0068] In addition, this oil recovery system S2 removes water and garbage from the pooled wastewater, efficiently recovers oil, sludge, and other components, and reuses energy (resource recovery). This oil recovery system S2 can be installed on-site within a facility, such as a fuel manufacturing plant or a commercial facility (e.g., a fast food chain restaurant). For example, a field agent (a professional company to which the applicant provides unique know-how, guidance, training, and certification) may provide a service of cleaning and managing grease traps at restaurants and managing this oil recovery system S2.

[0069] Next, an oil recovery system S2 according to the second embodiment will be described with reference to Fig. 10. In this oil recovery system S2, a water / residue tank WRT is provided in addition to the recovery tank T in the first embodiment. Note that a float sensor is not essential in the recovery tank T according to the second embodiment, but other configurations are almost the same as those in the first embodiment, so detailed description thereof will be omitted.

[0070] This water / residue tank WRT is a tank for extracting and storing the residue and water separated at the bottom when the recovery tank T is heated from a water / residue recovery valve (e.g., a 40A electric hole valve drain) WI provided on the bottom of the recovery tank T. The water / residue tank WRT has a rectangular parallelepiped shape, with dimensions of, for example, width 1500 mm x height 570-650 mm x depth 1100 mm (capacity approximately 300 L). Note that the shape of the water / residue tank WRT is not limited to the shape shown in this figure, and other shapes such as a cylindrical shape may be used as long as it has the same function.

[0071] 12, the water / residue tank WRT has a number of removable cover plates 6 on its top surface. The cover plates 6 are fixed to the top surface of the water / residue tank WRT using knob bolts 62 via packing 61. In addition, a water / residue removal valve W2 such as a 40A socket is provided on the side surface.

[0072] In addition, since wastewater is directly introduced into the recovery tank T in the second embodiment from a grease trap or the like, it is expected that floating garbage will remain in the upper layer. In that case, a floating garbage recovery valve (manual valve) with a relatively large diameter may be provided specifically for this purpose on the side of the recovery tank T, and the floating garbage may be efficiently removed from the valve using a suction pump. Alternatively, the floating garbage may be manually recovered by periodically opening the cover plate 6 of the recovery tank T.

[0073] Next, the transition state of the stored contents in the recovery tank T according to the second embodiment will be described with reference to Fig. 13 and Fig. 14. First, wastewater from a grease trap or the like is transferred into the recovery tank T. This transfer is performed within the same facility and may be performed manually by an operator using a dedicated tool, or may be performed automatically via an inlet pipe by turning on an electric pump switch.

[0074] Next, when the wastewater reaches a predetermined amount inside the recovery tank T, the tank heating section H starts to heat the inflowing water until it reaches about 70 degrees. When it reaches about 70 degrees, the wastewater is separated into layers of residue, water, oil-containing floating sludge (so-called black oil), oil, and floating garbage from the bottom, as shown in Figure 13(a).

[0075] Then, when the heating of the wastewater is completed (i.e., separation into each layer is completed), the water / residue removal valve W1 formed on the bottom of the recovery tank T is opened, and the residue and water on the bottom side of the recovery tank T are transferred to the water / residue tank WRT. When the residue and inflow water in the recovery tank T are removed, sludge, oil, and floating garbage are stored in the recovery tank T from the bottom layer, as shown in Figure 13(b).

[0076] The discharged residue and water are temporarily stored in the water / residue tank WRT. The residue is discharged outside the water / residue tank WRT via a 40A HT hole valve or the like formed on the side bottom of the water / residue tank WRT and collected in a dedicated tank, where it can be disposed of as industrial waste. On the other hand, the water is discharged into the wastewater treatment reactor 17 after impurities such as impurities have been removed using, for example, the purification and transfer device 12.

[0077] Next, when a sludge layer is included, the sludge is stored on the bottom side of the recovery tank T as shown in Fig. 13(b), and this sludge may be manually recovered using the manual valve 18. The recovered sludge is then transferred via the sludge removal device 15 to a sludge industrial waste tank (for example, a lorry tank 16 (W800mm x L630mm x H630mm, capacity 200L)) for industrial waste treatment.

[0078] When the sludge layer is discharged, the oil falls and accumulates, but when the oil falls to the bottom side of the recovery tank T, the recovery tank T goes into the state shown in Fig. 14(c), and the oil sensor OS detects the oil. Then, the oil purification / transfer lamp lights up, so the worker releases the fixing of the cover device 5 using the slide bar 52. Then, the action of the float plate 53 causes the top surface of the cover device 5 to automatically float above the oil, after which the oil removal valve OV is opened and the electric pump is turned on.

[0079] Then, only the oil in the recovery tank T is recovered, and the inside of the recovery tank T transitions to the state shown in Figure 14 (d). The recovered oil is purified by the refinement and transfer device 12 to remove excess impurities, and is then collected in the refined oil tank (IBC container) 13.

[0080] The floating debris that accumulates in the state shown in Fig. 14(d) does not enter the oil suction space AS due to the presence of the waste solid remover 4 and the cover 5. For example, if the floating debris is mixed in, the floating debris can be appropriately prevented from entering the suction space AS by moving the cover 5 up and down according to the liquid level detected by the float sensor FS. This floating debris is removed periodically or when it reaches a predetermined amount, for example, from a dedicated outlet provided on the bottom side of the recovery tank T, or an operator opens the cover plate 3 of the recovery tank T and manually collects it.

[0081] In this manner, in the second embodiment, as in the first embodiment, it is no longer necessary to open the cover plate 3 of the recovery tank T and insert the purification transfer vessel each time, improving the work efficiency. Also, since the oil recovery (recycling) work can be performed without opening the cover plate 3 of the recovery tank T or the cover plate 6 of the water / residue tank WRT, odors are less likely to be generated.

[0082] In this manner, the water, sludge, and oil in the recovery tank T are separated, completing a series of recovery operations. After this, when the capacity of the grease trap or the like becomes full, the wastewater is transported to the recovery tank T, and the process is repeated from the state shown in Figure 13(a).

[0083] As explained above, the second embodiment can achieve the same effects as the first embodiment. That is, (1) since the recycling work can be performed without opening the cover plate 3 of the recovery tank T or the cover plate 6 of the water / residue tank WRT, odors are less likely to be generated. (2) Both the oil refining and transfer and the sludge removal are close to being automated, so there is no workload. (3) Since the recovery tank T is equipped with the water / residue tank WRT, even if the residue flows into the recovery tank T, the water and residue can be easily transferred and managed in the water / residue tank WRT.

[0084] The present invention is not limited to the configuration of the above embodiment, and various modifications are possible within the scope of the invention. For example, in order to increase the speed of oil recovery, multiple oil selective separation mechanisms S1 can be provided in the oil and sludge recovery tank T. [Explanation of symbols]

[0085] S, S2 Oil recovery system S1 Oil selective separation mechanism T Oil and sludge recovery tank (recovery tank) OV Oil Extraction Valve OS oil / water separation tank AS Suction space H Tank heating section WRV Water and Residue Recovery Tank W1 Water / residue recovery valve WV Water discharge valve DV Sludge discharge valve P1 Oil supply pipe P2 circulation piping 3,6 Lid plate 4 Waste solids remover 4a~4c Waste solids removal plate 5 Cover 11 Inlet valve 14 Exhaust valve 32 Through hole 41 Thin plate 42 Punching holes 43 Glass wool 51 Intrusion prevention wall 52 Slide bar 53 Float Board

Claims

1. An oil and sludge recovery tank for recovering reusable oil and sludge from oil-containing wastewater, An oil removal valve provided on the bottom side of the side of the oil and sludge recovery tank; a waste solids remover installed upright on the bottom surface of the oil and sludge recovery tank; a suction space surrounded by the side surface and the waste solid remover, for sucking oil stored in the oil and sludge recovery tank through the oil removal valve; An oil and sludge recovery tank, characterized in that the waste solid remover has an oil selection function that selectively allows oil to pass through.

2. The oil and sludge recovery tank according to claim 1, characterized in that the waste solid removal body has a U-shape when viewed from above and is composed of three rectangular prism-shaped waste solid removal plates erected from the bottom surface of the oil and sludge recovery tank.

3. As the oil selection function, a plurality of punched holes are formed on the surface of the waste solid content remover, and the internal space of the waste solid content remover is filled with glass wool; 3. The oil and sludge recovery tank according to claim 2, wherein a thin plate is disposed on the bottom side of the waste solid remover to serve as a wall for preventing water from being injected into the tank.

4. 3. The oil and sludge recovery tank according to claim 1, further comprising a cover for covering the suction space and the waste solid remover from the outside.

5. The cover has three side surfaces and a top surface formed of plate-shaped intrusion prevention walls, and one side surface and a bottom surface are open, 5. The oil and sludge recovery tank according to claim 4, wherein a vertically extending slide bar is connected to an upper surface of the cover.

6. The oil and sludge recovery tank further comprises: A cover plate is provided so as to be removable, and in a closed state, the cover plate keeps the oil and sludge collection tank sealed.

6. The oil and sludge recovery tank according to claim 5, wherein the slide bar of the cover passes through a through hole formed in the lid plate and is slidable in the vertical direction.

7. 5. The oil and sludge recovery tank according to claim 4, wherein a float plate is integrally provided on an upper surface of the cover.

8. The oil and sludge recovery tank has a substantially rectangular parallelepiped shape, The bottom surface of the tank is provided with a water discharge valve for discharging water and a sludge discharge valve for removing sludge.

2. The oil and sludge recovery tank according to claim 1, further comprising a tank heating section provided in a planar shape on at least one of the side surface and the bottom surface of the tank.

9. 2. An oil recovery system comprising an oil supply pipe that sends an upper layer from an oil-water separation tank to a circulation pipe that returns to the oil-water separation tank via the oil and sludge recovery tank described in claim 1, and which performs an operation to recover oil and sludge from the oil-water separation tank using the oil and sludge recovery tank.

10. An oil recovery system comprising the oil and sludge recovery tank according to claim 1, The oil and sludge recovery tank further comprises: A water / residue recovery valve is provided on the bottom of the oil and sludge recovery tank to recover the residue and water separated at the bottom, The oil recovery system is characterized in that it has a water / residue tank connected to the water / residue recovery valve for storing the water and residue extracted from the water / residue recovery valve.

11. The water / residue tank further comprises: The oil recovery system according to claim 10, further comprising a detachable cover plate that maintains a tight seal with the water / residue tank when in a closed state.

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