Fuel oil mixing system and fuel oil mixing method

Abstract

This fuel oil mixing system (1) is a system for generating a purified fuel oil (CO) that is a purified product of a mixed fuel oil (MO) that is a mixture of a mineral-based fuel oil (FO) and a biodiesel fuel oil (BO). The fuel oil mixing system (1) is provided with a fuel oil purifier (21) which is arranged in a ship, a storage tank (71) in which a mineral-based fuel oil (FO) is stored, and a biodiesel tank (41) in which a biodiesel fuel oil (BO) is stored. The fuel oil mixing system (1) supplies a mixed fuel oil (MO) into the fuel oil purifier (21), in which the mixed fuel oil (MO) is produced by mixing the mineral-based fuel oil (FO) in the storage tank (71) with the biodiesel fuel oil (BO) in the biodiesel tank (41).

Description

[Technical field]

[0001] The present invention relates to a fuel oil mixing system and a fuel oil mixing method for producing a mixed fuel oil by mixing a mineral fuel oil (petroleum fuel oil) and a biodiesel fuel oil. [Background technology]

[0002] In recent years, reducing greenhouse gas emissions has been attracting attention as a measure to combat global warming. For this reason, in internal combustion engines, combustion devices, and the like, efforts are being made to reduce the consumption of mineral fuel oil (e.g., petroleum fuels such as gasoline and heavy oil) and the like by using mixed fuel oils obtained by mixing other fuels, etc., in order to reduce the amount of mineral fuel oil consumed and to reduce the environmental load (see, for example, Patent Document 1).

[0003] One example of alternative fuels for reducing greenhouse gas emissions in international shipping is biodiesel fuel, which is treated as a carbon-neutral fuel.

[0004] Among alternative fuels, biodiesel fuel oil has the advantage that it can be used relatively easily in existing diesel engines. Generally, biodiesel fuel oil is mixed with existing mineral fuel oil and used as fuel for propulsion engines, generator engines, boilers, etc.

[0005] Methods for mixing petroleum-based fuel oil and biodiesel fuel oil include a method in which the mixed fuel oil mixed at a land facility is loaded onto a ship and used, and a method in which the petroleum-based fuel oil and the biodiesel fuel oil are loaded onto a ship separately and mixed to produce a mixed fuel oil.

[0006] One method for mixing mineral fuel oil and biodiesel fuel oil on board a ship is to temporarily store the mineral fuel oil and biodiesel fuel oil in separate storage tanks, then transfer each fuel to a tank that stores the mixed fuel oil and let them join in the tank. Another mixing method is to let the respective fuels join in the middle of the piping that transfers them to the tank that stores the mixed fuel oil. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 4733711 Summary of the Invention [Problem to be solved by the invention]

[0008] The properties of mineral fuel oil and biodiesel fuel oil are various, and the viscosity and specific gravity of the two may be different. In such a case, the method of joining the mineral fuel oil and the biodiesel fuel oil in a storage tank or joining them in the middle of a transfer pipe has a problem that the mixing state may be insufficient.

[0009] Since mineral fuel oil and biodiesel fuel oil have different heating values, there has been a problem in that if the mixing state is insufficient, fluctuations in engine output and boiler output occur.

[0010] Although it is possible to achieve sufficient agitation of the mixed fuel oil using existing technology, there is a problem in that it requires additional equipment costs and modifications.

[0011] The present invention aims to provide a fuel oil mixing system and a fuel oil mixing method that can solve the above-mentioned problems, efficiently mix mineral fuel oil and biodiesel fuel oil, and remove sludge generated by mixing. [Means for solving the problem]

[0012] In order to solve the above problems, the present invention provides a fuel oil mixing system for producing purified fuel oil by purifying a mixed fuel oil obtained by mixing mineral fuel oil with biodiesel fuel oil, the system comprising a fuel oil purifier arranged on board a ship, a first tank for storing the mineral fuel oil, and a second tank for storing the biodiesel fuel oil, and the mixed fuel oil produced by mixing the mineral fuel oil in the first tank and the biodiesel fuel oil in the second tank is supplied to the fuel oil purifier.

[0013] The present invention also relates to a fuel oil mixing system for producing purified fuel oil by purifying a mixed fuel oil obtained by mixing mineral fuel oil with biodiesel fuel oil, the system comprising a fuel oil purifier arranged on board a ship, a first tank for storing the mineral fuel oil, a second tank for storing the biodiesel fuel oil, a purifier inlet line for supplying the mineral fuel oil in the first tank to the fuel oil purifier, and a biofuel supply line for supplying the biodiesel fuel oil in the second tank to the purifier inlet line.

[0014] The present invention also provides a fuel oil mixing method for producing a mixed fuel oil by mixing mineral fuel oil with biodiesel fuel oil on board a ship, and for producing a clean fuel oil by purifying the mixed fuel oil, in which the biodiesel fuel oil is merged with the mineral fuel oil upstream of a fuel oil purifier to produce the mixed fuel oil, and the clean fuel oil is produced by supplying the mixed fuel oil to the fuel oil purifier. Effect of the Invention

[0015] The fuel oil mixing system and fuel oil mixing method of the present invention can efficiently mix mineral fuel oil and biodiesel fuel oil automatically or manually, and can also remove sludge produced by mixing. [Brief description of the drawings]

[0016] [Figure 1] 1 is a schematic configuration diagram showing a fuel oil mixing system and a fuel oil mixing method according to a first embodiment of the present invention. [Diagram 2] FIG. 4 is a schematic configuration diagram showing a fuel oil mixing system and a fuel oil mixing method according to a second embodiment of the present invention. [Diagram 3] FIG. 4 is a schematic configuration diagram showing a fuel oil mixing system and a fuel oil mixing method according to a third embodiment of the present invention. [Figure 4] FIG. 2 is a schematic diagram showing a first modified example of the fuel oil mixing system and the fuel oil mixing method according to the present invention. [Diagram 5] FIG. 2 is a schematic diagram showing a second modified example of the fuel oil mixing system and the fuel oil mixing method according to the present invention. [Figure 6] FIG. 4 is a schematic diagram showing a third modified example of the fuel oil mixing system and the fuel oil mixing method according to the present invention. [Figure 7] FIG. 11 is a schematic diagram showing a fourth modified example of the fuel oil mixing system and the fuel oil mixing method according to the present invention. [Figure 8] FIG. 11 is a schematic diagram showing a fifth modified example of the fuel oil mixing system and the fuel oil mixing method according to the present invention. [Figure 9] FIG. 13 is a schematic configuration diagram of a main portion showing a sixth modified example of the fuel oil mixing system and the fuel oil mixing method according to the present invention. [Figure 10] FIG. 13 is a schematic diagram showing a seventh modified example of the fuel oil mixing system and the fuel oil mixing method according to the present invention. [Figure 11] FIG. 13 is a schematic diagram showing an eighth modified example of the fuel oil mixing system and fuel oil mixing method according to the present invention. [Figure 12] FIG. 13 is a schematic configuration diagram of a main part showing a ninth modified example of the fuel oil mixing system and the fuel oil mixing method according to the present invention. [Figure 13] FIG. 1 is a schematic configuration diagram showing a fuel oil mixing system and a fuel oil mixing method according to a fourth embodiment of the present invention. [Figure 14] FIG. 15 is a schematic diagram showing a tenth modified example of the fuel oil mixing system and fuel oil mixing method according to the present invention. [Figure 15] FIG. 15 is a schematic diagram showing an eleventh modified example of the fuel oil mixing system and fuel oil mixing method according to the present invention. [Figure 16]FIG. 21 is a schematic diagram showing a twelfth modified example of the fuel oil mixing system and fuel oil mixing method according to the present invention. [Figure 17] FIG. 2 is a schematic diagram showing a thirteenth modified example of the fuel oil mixing system and fuel oil mixing method according to the present invention. [Figure 18] FIG. 21 is a schematic diagram showing a fourteenth modified example of the fuel oil mixing system and fuel oil mixing method according to the present invention. [Figure 19] FIG. 2 is a schematic diagram showing a fifteenth modified example of the fuel oil mixing system and fuel oil mixing method according to the present invention. [Figure 20] FIG. 21 is a schematic diagram showing a sixteenth modified example of the fuel oil mixing system and fuel oil mixing method according to the present invention. [Figure 21] FIG. 21 is a schematic diagram showing a seventeenth modified example of the fuel oil mixing system and fuel oil mixing method according to the present invention. [Figure 22] FIG. 2 is a schematic diagram showing an 18th modified example of the fuel oil mixing system and fuel oil mixing method according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] [First embodiment] A fuel oil mixing system 1 and a fuel oil mixing method according to a first embodiment of the present invention will be described in detail with reference to Fig. 1. In the following description, the up-down direction will be described as the vertical direction perpendicular to the liquid levels of the fuel stored in the first tank 11, the service tank 31, and the second tank 41 in Fig. 1.

[0018] <Fuel oil mixing system> The fuel oil mixing system 1 shown in FIG. 1 is an apparatus for producing mixed fuel oil MO (hereinafter, referred to as "MO") by mixing mineral fuel oil FO (hereinafter, referred to as "FO") and biodiesel fuel oil BO (hereinafter, referred to as "BO"), and further producing clean fuel oil CO (hereinafter, referred to as "CO") by purifying the mixed fuel oil MO. The clean fuel oil CO is used for engines, auxiliary machinery, etc. of a ship. The fuel oil mixing system 1 mainly includes a first tank 11, a second tank 41, a fuel oil purifier 21, a purifier inlet line 12, a biofuel supply line 42, and a service tank 31. The fuel oil mixing system 1 is arranged inside the ship.

[0019] <Mineral fuel oil> Mineral fuel oil FO (also called fuel oil) is a petroleum-based fuel oil that has been conventionally used in ships and the like. Examples of fuel oil include C heavy oil, A heavy oil, and SOx regulation-compliant oil (sulfur content of 0.5% by mass or less). The mineral fuel oil FO is stored in a fuel oil storage tank (not shown) arranged on the ship. The mineral fuel oil FO is transferred to and stored in the first tank 11 when producing a mixed fuel oil MO, etc.

[0020] <Biodiesel fuel oil> Biodiesel fuel oil BO is a carbon-neutral fuel that balances greenhouse gas emissions and absorption. Biodiesel fuel oil BO is an ecological fuel for diesel engines made from vegetable oils such as rapeseed oil, palm oil, olive oil, sunflower oil, and soybean oil, as well as waste cooking oils such as tempura oil. The main component of biodiesel fuel oil BO is fatty acid methyl ester. Biodiesel fuel oil BO has almost the same fuel economy and driving performance as diesel fuel.

[0021] <Mixed fuel oil> The mixed fuel oil MO is a fuel produced by mixing a mineral fuel oil FO and a biodiesel fuel oil BO. The mixed fuel oil MO is produced by merging a mineral fuel oil FO with a biodiesel fuel oil BO upstream of the fuel oil purifier 21. In the mixed fuel oil MO, the mixture of the mineral fuel oil FO and the biodiesel fuel oil BO progresses even in the process from the merging point a to the fuel oil purifier 21. Since the degree of mixing of the mixed fuel oil MO differs before and after the fuel oil purifier 21, in the following description, the mixed fuel oil MO that has passed through the fuel oil purifier 21 is referred to as "clean fuel oil CO."

[0022] <Clean fuel oil> The clean fuel oil CO is a fuel oil obtained by purifying the mixed fuel oil MO by the fuel oil purifier 21. The clean fuel oil CO is temporarily stored in the service tank 31 from the fuel oil purifier 21 via the clean fuel oil line 22, and then supplied to the engine or auxiliary machinery (e.g., generator, boiler, etc.) of the ship.

[0023] <First Tank> The first tank 11 is a fuel oil storage tank (settling tank) for temporarily storing the mineral fuel oil FO sent by a transfer pump from a fuel oil storage tank (not shown). A fuel oil discharge port 11a for sending the fuel oil to the purifier inlet line 12 is formed in the lower part of the first tank 11. The fuel oil storage tank is a bottom tank having a capacity capable of storing the mineral fuel oil FO required during navigation, and is often formed in the bottom of the ship. Incidentally, since the mineral fuel oil FO is not sent directly from a fuel oil storage tank (not shown) to the fuel oil purifier 21, the first tank 11 (settling tank) is necessary.

[0024] The first tank 11 is formed in a size capable of storing approximately one-tenth of the capacity of a fuel oil storage tank (not shown). In addition, the pump capacity of a fuel transfer pump (not shown) is about 10 times larger than that of the purifier fuel supply pump 13 so that the mineral fuel oil FO can be transferred from a fuel oil storage tank (not shown) to the first tank 11 in a short period of time.

[0025] The timing for transferring the mineral fuel oil FO from the fuel oil storage tank to the first tank 11 is when the liquid level of the mineral fuel oil FO in the first tank 11 falls below a predetermined liquid level. Therefore, the operating time of the fuel transfer pump (not shown) is shorter than that of the purifier fuel supply pump 13. In addition, the transfer pipe extending from the fuel oil storage tank to the first tank 11 has a larger diameter than the pipe arranged around the purifier fuel supply pump 13 .

[0026] <Purifier inlet line> The purifier inlet line 12 is a fuel oil supply flow path for supplying the mineral fuel oil FO in the first tank 11 to the fuel oil purifier 21. The purifier inlet line 12 is composed of a piping path that runs from the fuel oil discharge port 11a of the first tank 11 to the inlet 21a of the fuel oil purifier 21 via the junction a with the biofuel supply line 42. The purifier inlet line 12 is made up of an upstream purifier inlet line 12a from the fuel oil discharge port 11a to the junction a, and a downstream purifier inlet line 12b from the junction a to the inlet 21a of the fuel oil purifier 21.

[0027] The upstream purifier inlet line 12a is a flow path for sending the mineral fuel oil FO in the first tank 11 to the junction a. In the upstream purifier inlet line 12a, a purifier fuel supply pump 13, a purifier fuel flow meter 14, and the junction a are installed in this order at appropriate intervals from the first tank 11 side.

[0028] When the biodiesel fuel oil BO and the mineral fuel oil FO in the biofuel supply line 42 are mixed in the upstream purifier inlet line 12a, a flow rate adjustment mechanism for adjusting the mixing ratio may be added to the upstream purifier inlet line 12a. The flow rate adjustment mechanism is preferably sized to suit the size of the piping of the upstream purifier inlet line 12a. As the flow rate adjusting mechanism, in addition to the installation of a flow meter, it is preferable to add a second purifier return line 17B (see FIG. 3) to the first tank 11, a nozzle, an adjustment valve, or to operate a transfer pump.

[0029] The downstream purifier inlet line 12b is a flow path that sends the mineral fuel oil FO in the first tank 11 and the biodiesel fuel oil BO (unpurified mixed fuel oil MO) in the second tank 41 that are joined at the joining point a to the inlet 21a. In the embodiment of FIG. 1, for example, when the mixing ratio of biodiesel fuel oil BO to mineral fuel oil FO is 30%, the flow rate of the downstream purifier inlet line 12b is about 30% higher than that of the upstream purifier inlet line 12a. Therefore, it is preferable to set the piping size of the downstream purifier inlet line 12b taking this into consideration.

[0030] <Purifier fuel supply pump> The purifier fuel supply pump 13 is a pump for sending the mineral fuel oil FO in the upstream purifier inlet line 12a to the junction a side. The purifier fuel supply pump 13 is installed between the fuel oil discharge port 11a and a purifier fuel flow meter 14 provided in the upstream purifier inlet line 12a.

[0031] <Purifier fuel flow meter> The purifier fuel flow meter 14 is a flow meter that measures the flow rate of the mineral fuel oil FO sent from the first tank 11 to the junction a when the mineral fuel oil FO and the biodiesel fuel oil BO are joined at the junction a. The purifier fuel flow meter 14 is installed between the purifier fuel supply pump 13 of the upstream purifier inlet line 12a and the junction a. The purifier fuel flow meter 14 may be installed at a location other than that shown in FIG. 1, for example, between the fuel oil discharge port 11a and the purifier fuel supply pump 13 of the upstream purifier inlet line 12a.

[0032] <Confluence point> The junction a is a point where the upstream purifier inlet line 12a and the biofuel supply line 42 are connected. Therefore, at the junction a, the mineral fuel oil FO in the upstream purifier inlet line 12a and the biodiesel fuel oil BO in the biofuel supply line 42 are joined and mixed.

[0033] <Mixer> A mixer (not shown) may be installed downstream of the junction a (on the line connecting the junction a and the inlet 21a). Examples of the mixer include a static mixer and an in-line mixer such as a Venturi mixer, but the mixer is not limited to these, and any means capable of mixing two types of fuel oil may be used.

[0034] <Second Tank> The second tank 41 is a biodiesel fuel tank for temporarily storing the biodiesel fuel BO. A biodiesel fuel outlet 41a for sending the biodiesel fuel BO to the biofuel supply line 42 is formed at the bottom of the second tank 41.

[0035] <Biofuel supply line> The biofuel supply line 42 is composed of a piping for sending the biodiesel fuel oil BO in the second tank 41 to the purifier inlet line 12. In the biofuel supply line 42, a biofuel supply pump 43, a biofuel supply flow meter 44, and a shutoff valve 45 are installed in this order at appropriate intervals from the second tank 41 side. It is preferable that the piping of the biofuel supply line 42 for transporting the biodiesel fuel oil BO be made of stainless steel.

[0036] <Biofuel supply pump> The biofuel supply pump 43 is a pump for sending the biodiesel fuel oil BO in the biofuel supply line 42 to the junction a via the biofuel supply flow meter 44 and the shutoff valve 45. The biofuel supply pump 43 is installed between the biodiesel fuel oil discharge port 41a and the biofuel supply flow meter 44 of the biofuel supply line 42.

[0037] <Biofuel supply flow meter> The biofuel supply flow meter 44 is a flow meter that measures the flow rate of the biodiesel fuel oil BO sent to the junction a. The biofuel supply flow meter 44 is installed between the biofuel supply pump 43 and the shutoff valve 45 of the biofuel supply line 42. The biofuel supply flow meter 44 may be installed on the downstream side of the shutoff valve 45.

[0038] The purifier fuel flow meter 14 and the biofuel supply flow meter 44 are provided to adjust the mixing ratio of the mineral fuel oil FO and the biodiesel fuel oil BO. As an example of the mixing ratio, the flow rate of the mineral fuel oil FO flowing from the first tank 11 to the upstream purifier inlet line 12a is 70%, and the flow rate of the biodiesel fuel oil BO flowing from the second tank 41 to the biofuel supply line 42 is 30%. Note that this mixing ratio is just an example and is not limited to this ratio.

[0039] <Shut-off valve> The shutoff valve 45 is a valve for allowing or blocking the flow of the biodiesel fuel oil BO in the biofuel supply line 42 to the junction a. The shutoff valve 45 is installed between the biofuel supply flow meter 44 of the biofuel supply line 42 and the junction a. The shutoff valve 45 is electrically connected to a control device (not shown).

[0040] <Fuel oil purifier> The fuel oil purifier 21 is a purifier for purifying the mixed fuel oil MO. In the following first embodiment, it will be described how the water and solids contained in the oil are separated and purified by centrifugal separation, but a filter may be used as a purification means instead of a centrifuge. As a filtering method, any method such as pressure filtration, vacuum filtration, reduced pressure filtration, gravity filtration, centrifugal filtration, etc. may be used. In the following, in this first embodiment, the fuel oil purifier 21 may be a filter, but the case of a centrifuge will be described as an example.

[0041] The fuel oil purifier 21 of the first embodiment is a known centrifuge that separates the mixed fuel oil MO into solid and liquid or liquid and liquid by the high centrifugal force of a rotor rotating at high speed. The fuel oil purifier 21 is, for example, a separation plate type centrifuge equipped with a separation plate group in which separation plates are stacked inside a rotor. A separation plate type centrifuge can efficiently remove solids and moisture contained in the mixed fuel oil MO. The fuel oil purifier 21 is installed on board the ship between the junction a of the purifier inlet line 12 and the fuel purification oil line 22.

[0042] 1 shows only one fuel oil purifier 21, multiple fuel oil purifiers 21 may be arranged in parallel. In the following, in order to make the fuel oil mixing system 1 easier to understand, an example in which one fuel oil purifier 21 is provided will be described.

[0043] <Fuel purification line> The purified fuel oil line 22 is a flow path for sending the purified fuel oil CO obtained by purifying the mixed fuel oil MO by the fuel oil purifier 21 to the service tank 31. The purified fuel oil line 22 is composed of a piping path from the discharge port 21b of the fuel oil purifier 21 to the purified fuel oil supply port 31a of the service tank 31.

[0044] <Service tank> The service tank 31 is a tank for storing clean fuel oil CO. The clean fuel oil CO in the service tank 31 is supplied to the engine or auxiliary machinery (e.g., generator, boiler, etc.) of the ship. The service tank 31 is provided with a clean fuel oil supply port 31a and an overflow pipe 32. The service tank 31 is installed at the most downstream portion of the clean fuel oil line 22.

[0045] The clean fuel oil supply port 31a is an outlet of the clean fuel oil line 22. The clean fuel oil supply port 31a is provided at the top of the service tank 31.

[0046] <Overflow pipe> The overflow pipe 32 is for keeping the liquid level of the clean fuel oil CO constant in the service tank 31. The overflow pipe 32 is installed between the service tank 31 and the first tank 11.

[0047] ≪Effect≫ Next, the operation of the fuel oil mixing system 1 and the fuel oil mixing method according to the first embodiment of the present invention will be described with reference to FIG.

[0048] First, the mineral fuel oil FO outside the ship is sent to a fuel oil storage tank (not shown) inside the ship for storage, and the biodiesel fuel oil BO outside the ship is sent to a second tank 41 inside the ship for storage.

[0049] Next, the mineral fuel oil FO stored in a fuel oil storage tank (not shown) is sent to the first tank 11 by a transfer pump (not shown). When the liquid level of the mineral fuel oil FO in the first tank 11 drops to a predetermined low liquid level, the mineral fuel oil FO in the fuel oil storage tank (not shown) is automatically transferred to the first tank 11 by the fuel transfer pump. Then, when the liquid level of the mineral fuel oil FO in the first tank 11 reaches a predetermined high liquid level, the transfer of the mineral fuel oil FO to the first tank 11 is stopped.

[0050] When the mineral fuel oil FO in the first tank 11 is to be supplied to the fuel oil purifier 21, the purifier fuel supply pump 13 is driven. When the purifier fuel supply pump 13 is driven, the mineral fuel oil FO is sucked out from the fuel oil discharge port 11a and sent to the junction a side via the purifier fuel flow meter 14.

[0051] When the biodiesel fuel oil BO in the second tank 41 is supplied to the fuel oil purifier 21, the shutoff valve 45 is opened and the biofuel supply pump 43 is driven. Then, the biodiesel fuel oil BO is sucked from the biodiesel fuel oil discharge port 41a to the biofuel supply line 42 by the biofuel supply pump 43 and sent to the junction a side via the biofuel supply pump 43, the biofuel supply flow meter 44, and the shutoff valve 45.

[0052] At a junction a on the upstream side of the fuel oil purifier 21, the mineral fuel oil FO in the upstream purifier inlet line 12a and the biodiesel fuel oil BO in the biofuel supply line 42 join together to produce a mixed fuel oil MO. The mixed fuel oil MO passes through the downstream purifier inlet line 12b and is sent from the inlet 21a into the fuel oil purifier 21. The mixed fuel oil MO is subjected to centrifugal force in the fuel oil purifier 21, whereby impurities such as solids and moisture are removed, and further stirring and mixing of the mineral fuel oil FO and the biodiesel fuel oil BO progresses.

[0053] The purified fuel oil CO obtained by purifying the mixed fuel oil MO in the fuel oil purifier 21 is sent from the fuel oil purifier 21 to the service tank 31 through the purified fuel oil line 22 and temporarily stored in the service tank 31. The purified fuel oil CO in the service tank 31 is supplied to the ship's engine or auxiliary machinery for use as needed.

[0054] Thus, the first embodiment of the present invention, as shown in FIG. 1, is a fuel oil mixing system 1 for producing purified fuel oil CO by purifying a mixed fuel oil MO obtained by mixing a mineral fuel oil FO with a biodiesel fuel oil BO, and includes a fuel oil purifier 21 arranged on a ship, a first tank 11 for storing the mineral fuel oil FO, a second tank 41 for storing the biodiesel fuel oil BO, a purifier inlet line 12 for supplying the mineral fuel oil FO in the first tank 11 to the fuel oil purifier 21, and a biofuel supply line 42 for supplying the biodiesel fuel oil BO in the second tank 41 to the purifier inlet line 12.

[0055] The fuel oil mixing system 1 of the present invention has a junction a on board the ship where the downstream of the biofuel supply line 42 joins the purifier inlet line 12. Therefore, the fuel oil mixing system 1 can efficiently mix the mineral fuel oil FO and the biodiesel fuel oil BO on board the ship, and the mixed fuel oil MO can be supplied to the ship's engine or auxiliary machinery for use. The fuel oil blending system 1 further includes a fuel oil purifier 21 that purifies the blended fuel oil MO to produce clean fuel oil CO. The fuel oil purifier 21 not only purifies the blended fuel oil MO, but also acts to mix the mineral fuel oil FO and the biodiesel fuel oil BO, and can therefore remove sludge produced by mixing. Therefore, the present invention produces clean fuel oil CO with few impurities and in which the biodiesel fuel oil BO is uniformly dispersed in the mineral fuel oil FO, and the clean fuel oil CO can be supplied to the ship's engine or auxiliary machinery for use.

[0056] The first tank 11 is a settling tank provided separately from a fuel oil storage tank (not shown).

[0057] According to this configuration, the mineral fuel oil FO for producing the mixed fuel oil MO can be stored, so that the mineral fuel oil FO can be heated to a certain temperature from the fuel oil storage tank and left to stand, so that solids and water can be separated by settling to the bottom of the tank. In addition, the excess of the clean fuel oil CO sent to the service tank 31 can be returned to the first tank 11 via the overflow pipe 32, so that the liquid level of the service tank 31 can be kept constantly full.

[0058] As shown in FIG. 1, the fuel oil mixing system 1 is also provided with a service tank 31 for storing the mixed fuel oil MO (cleaned fuel oil CO) purified by the fuel oil purifier 21.

[0059] According to this configuration, the mixed fuel oil MO (clean fuel oil CO) purified by the fuel oil purifier 21 can be stored in the service tank 31, so that the clean fuel oil CO can be supplied to the ship's engine or auxiliary machinery for use at any time.

[0060] Also, as shown in FIG. 1 , the first embodiment is a fuel oil mixing method for producing a mixed fuel oil MO by mixing a mineral fuel oil FO with a biodiesel fuel oil BO on board a ship, and for producing clean fuel oil CO by purifying the mixed fuel oil MO, in which the mineral fuel oil FO is mixed with the biodiesel fuel oil BO upstream of the fuel oil purifier 21 to produce the mixed fuel oil MO, and the clean fuel oil CO is produced by supplying the mixed fuel oil MO to the fuel oil purifier 21.

[0061] There may be cases where the mineral fuel oil FO and biodiesel fuel oil BO are not mixed properly just by mixing them in a piping line. If they are stored or left to stand in a tank in this state, the mineral fuel oil FO and biodiesel fuel oil BO may separate due to the insufficient mixing.

[0062] According to the first embodiment, the mineral fuel oil FO and the biodiesel fuel oil BO are mixed in a piping line, and after mixing, before being left to stand in the service tank 31 or the like, the mixed fuel oil MO can be homogeneously mixed by the stirring and mixing action in the rotor of the fuel oil purifier 21, without the need to install a separate mixer or the like in the piping. In addition, before storing in the service tank 31, sludge generated by mixing is removed by the fuel oil purifier 21, and the purified fuel oil CO can be sent to the service tank 31.

[0063] [Second embodiment] Next, referring to Fig. 2, a fuel oil mixing system 1A and a fuel oil mixing method according to a second embodiment of the present invention will be described, focusing on the differences from the fuel oil mixing system 1 and the fuel oil mixing method according to the first embodiment. The configurations already described will be given the same reference numerals and the description thereof will be omitted. Fig. 2 is a schematic diagram showing the fuel oil mixing system 1A and the fuel oil mixing method according to the second embodiment of the present invention.

[0064] As shown in FIG. 2, the fuel oil mixing system 1A according to the second embodiment of the present invention differs from the first embodiment in that it is provided with a first purifier return line 17A (purifier return line) extending from the purifier inlet line 12 to the first tank 11, and that it is provided with a fuel oil switching means 16 downstream of the confluence a of the purifier inlet line 12 and the biofuel supply line 42, which switches the mixed fuel oil MO in the purifier inlet line 12 to flow through the first purifier return line 17A (purifier return line).

[0065] The first purifier return line 17A is configured as a piping path for returning the mineral fuel oil FO from the purifier inlet line 12 downstream of the junction a to the first tank 11. At the branching portion of the purifier inlet line 12 and the first purifier return line 17A, a fuel oil switching means 16 is provided for switching the mineral fuel oil FO of the purifier inlet line 12 (downstream purifier inlet line 12b) to flow to either the first purifier return line 17A side or the mixed fuel oil MO to the fuel oil purifier 21 side. The fuel oil switching means 16 is, for example, a three-way valve (switching valve). The fuel oil switching means 16 is electrically connected to a control device (not shown) and is controlled by the control device (not shown). The first purifier return line 17A is connected to the fuel oil switching means 16 on the upstream side and to the mixed fuel oil inlet 11b of the first tank 11 on the downstream side.

[0066] In this case, when the fuel oil purifier 21 is stopped and no fuel oil is being passed through the fuel oil purifier 21, the fuel oil switching means 16 is configured to flow to the first purifier return line 17A side. To operate the fuel oil purifier 21, first, the purifier fuel supply pump 13 is started and the mineral fuel oil FO is caused to flow into the purifier inlet line 12. At the same time, the fuel oil purifier 21 is started and the rotation speed is increased. The mineral fuel oil FO discharged by the purifier fuel supply pump 13 passes through the first oil heater H1 (see FIG. 4)) and returns to the first tank 11 in its entirety because the fuel oil switching means 16 has been switched to the first purifier return line 17A. During this time, the first oil heater H1 (see FIG. 4) is started up. It takes several minutes for the fuel oil purifier 21 to reach the rated rotation speed. When the rotation of the fuel oil purifier 21 reaches the rated speed and the outlet temperature of the first oil heater H1 (see FIG. 4) stabilizes, the automatic operation of the fuel oil purifier 21 starts. (Note that the fuel oil purifier 21 may be of a type that is manually operated.)

[0067] After the rotor of the fuel oil purifier 21 becomes capable of passing liquid, the fuel oil switching means 16 is switched to the fuel oil purifier 21 side, the mineral fuel oil FO is passed through the fuel oil purifier 21, and the purification process is started. When biodiesel fuel oil BO is mixed with mineral fuel oil FO, the biodiesel fuel oil switching means 45A opens at this timing and the biodiesel fuel oil BO is supplied to the purifier inlet line 12 and the junction a.

[0068] The purifier fuel supply pump 13 is a positive displacement, constant flow pump, so in order to adjust the amount of liquid passing through the fuel oil purifier 21, the valve of the mineral fuel oil flow control means 19 in the purifier bypass line 18 is adjusted, and the excess flow is returned to the first tank 11 via the first purifier return line 17A. In order to minimize the mixing of the biodiesel fuel oil BO into the first tank 11, the biodiesel fuel oil switching means 45A is opened to mix the biodiesel fuel oil BO only when the fuel oil switching means 16 is on the fuel oil purifier 21 side.

[0069] According to the second embodiment of the fuel oil mixing system 1A, the fuel oil switching means 16 switches to the fuel oil purifier 21 side only when passing the fuel oil through the fuel oil purifier 21, so that it can be easily switched to the first purifier return line 17A (purifier return line) when the fuel oil purifier 21 performs a sludge discharge process, etc.

[0070] In addition, the fuel oil mixing system 1A differs from the first embodiment in that a purifier bypass line 18 is provided to flow the mineral fuel oil FO in the upstream purifier inlet line 12a to the first purifier return line 17A, and in that a mineral fuel oil flow control means 19 is provided to switch the mineral fuel oil FO in the purifier inlet line 12 to flow through the first purifier return line 17A.

[0071] The purifier bypass line 18 is composed of a piping path extending from the discharge side of the purifier fuel supply pump 13 provided in the upstream purifier inlet line 12a to the first purifier return line 17A. The purifier bypass line branch point b, which is the branch point between the upstream purifier inlet line 12a and the purifier bypass line 18, is disposed between the purifier fuel supply pump 13 provided in the purifier inlet line 12 (upstream purifier inlet line 12a) and the purifier fuel flow meter 14. A mineral fuel oil flow rate adjustment means 19 is provided in the purifier bypass line 18 upstream of the junction point a between the purifier inlet line 12 and the biofuel supply line 42.

[0072] In addition, a mixer (not shown) is provided downstream of the junction a. Further, upstream of the junction a of the purifier inlet line 12 and the biofuel supply line 42, there is provided a mineral fuel oil flow rate adjustment means 19 that causes a part of the mineral fuel oil FO in the purifier inlet line 12 to flow to the purifier return line (first purifier return line 17A) side. The mineral fuel oil flow rate adjustment means 19 is electrically connected to a control device (not shown) and is controlled by the control device (not shown).

[0073] The downstream side of the purifier bypass line 18 may be connected to an appropriate position of the first purifier return line 17A. Therefore, when the fuel oil switching means 16 switches the flow path to the first purifier return line 17A while the purifier fuel supply pump 13 is in operation, the mineral fuel oil FO flowing out from the first tank 11 can be returned to the first tank 11 via the purifier bypass line 18 and the first purifier return line 17A.

[0074] In the second embodiment, a mixer (not shown) is provided downstream of the confluence a, so that the mineral fuel oil FO in the purifier inlet line 12 and the biodiesel fuel oil BO in the biofuel supply line 42 can be mixed efficiently. The purifier inlet line 12 is preferably provided with a first oil heater H1 or a second oil heater H2 (see Figs. 4 and 5). If the flow rate of the first oil heater H1 or the second oil heater H2 (see Figs. 4 and 5) changes, the temperature of the oil after heating becomes unstable or the equipment is damaged. Therefore, it is preferable to always keep a constant flow rate by a mineral fuel oil flow rate adjustment means 19. Since the fuel oil mixing system 1A is provided with the first purifier return line 17A, if the fuel oil purifier 21 is not in a state where it can be treated, the first oil heater H1 (see Fig. 4) can be continued to pass the oil by switching to the first purifier return line 17A. Therefore, the load fluctuation of the first oil heater H1 can be minimized.

[0075] In addition, the fuel oil mixing system 1A differs from the first embodiment in that it is equipped with a biodiesel return line 46 extending from the biofuel supply line 42 to the second tank 41, and a biodiesel fuel oil switching means 45A that switches the biodiesel fuel oil BO in the biofuel supply line 42 to flow to the biodiesel return line 46 side.

[0076] In the fuel oil mixing system 1A, a biodiesel return line 46 is connected to the biofuel supply line 42 between the biofuel supply pump 43 and the biofuel supply flow meter 44. The downstream side of the biodiesel return line 46 is connected to a biodiesel fuel oil return port 41b provided at the top of the second tank 41. Therefore, by driving the biofuel supply pump 43, the biodiesel fuel oil BO can be circulated from the second tank 41 through the biodiesel fuel oil discharge port 41a, the biofuel supply pump 43 of the biofuel supply line 42, the biodiesel return line 46, and the biodiesel fuel oil return port 41b to the second tank 41. The biodiesel fuel oil switching means 45A is electrically connected to a control device (not shown) and is controlled by the control device (not shown). In addition, the piping of the biodiesel return line 46 for conveying the biodiesel fuel oil BO is preferably made of stainless steel, similar to the piping of the biofuel supply line 42.

[0077] According to this configuration, by closing the biodiesel fuel switching means 45A, the biodiesel fuel oil BO that has flowed out from the second tank 41 into the biofuel supply line 42 can be returned to the second tank 41, making it easy to respond when the flow of fuel to the fuel oil purifier 21 is stopped. Also, by adjusting the degree to which the biodiesel fuel switching means 45A is opened, the amount of biodiesel fuel oil BO to be mixed with the mineral fuel oil FO can be adjusted to produce a mixed fuel oil MO with an appropriate mixture ratio.

[0078] [Third embodiment] Next, a fuel oil mixing system 1B according to a third embodiment of the present invention will be described with reference to Fig. 3, focusing on differences from the fuel oil mixing system 1 according to the first embodiment. Fig. 3 is a schematic diagram showing the fuel oil mixing system 1B and a fuel oil mixing method according to the third embodiment of the present invention.

[0079] As shown in FIG. 3, the fuel oil mixing system 1B according to the third embodiment of the present invention differs from the first embodiment in that it is provided with a second purifier return line 17B for supplying mineral fuel oil FO to the first tank 11 and a mineral fuel oil switching means 16B.

[0080] The second purifier return line 17B is a piping for returning the mineral fuel oil FO from the purifier inlet line 12 upstream of the junction a to the first tank 11. A mineral fuel oil switching means 16B is provided at the branch point between the purifier inlet line 12 and the second purifier return line 17B. The mineral fuel oil switching means 16B has a function of switching the mineral fuel oil FO of the purifier inlet line 12 (upstream purifier inlet line 12a) to flow to either the second purifier return line 17B side or the fuel oil purifier 21 side. The mineral fuel oil switching means 16B is composed of, for example, a three-way valve (switching valve). The mineral fuel oil switching means 16B may be configured by an opening / closing valve provided in the purifier inlet line 12 and the second purifier return line 17B.

[0081] According to this configuration, by switching the mineral fuel oil switching means 16B so that the mineral fuel oil FO does not flow toward the confluence point a, the mineral fuel oil FO flowing through the upstream purifier inlet line 12a can be returned to the first tank 11.

[0082] In addition, the fuel oil mixing system 1B differs from the first embodiment in that, like the fuel oil mixing system 1A of the second embodiment, the fuel oil mixing system 1B is provided with a flow rate control means 19 for mineral fuel oil on the discharge side of the purifier fuel supply pump 13 provided in the purifier inlet line 12 (upstream purifier inlet line 12a).

[0083] According to this configuration, by having the mineral fuel oil flow rate adjustment means 19, the flow rate of the mineral fuel oil FO flowing from the upstream purifier inlet line 12a to the junction a can be adjusted, and the mixing ratio with the biodiesel fuel oil BO in the biofuel supply line 42 can be adjusted.

[0084] Also, the fuel oil mixing system 1B differs from the first embodiment in that, like the fuel oil mixing system 1A of the second embodiment, a biodiesel return line 46 and a biodiesel fuel oil switching means 45A are provided. According to this configuration, by having the biodiesel return line 46 and the biodiesel fuel oil switching means 45A, the flow rate of the biodiesel fuel oil BO flowing from the biofuel supply line 42 to the junction a can be adjusted, and the mixing ratio with the mineral fuel oil FO in the upstream purifier inlet line 12a can be adjusted.

[0085] [Fourth embodiment] Next, a fuel oil mixing system 10A according to a fourth embodiment of the present invention will be described with reference to Fig. 13, focusing on the differences from the fuel oil mixing system 1 according to the first embodiment. Fig. 13 is a schematic diagram showing the fuel oil mixing system and the fuel oil mixing method according to the fourth embodiment of the present invention.

[0086] As shown in FIG. 13, the fuel oil mixing system 10A differs from the first to third embodiments in that it is provided with a storage tank 71 (first tank) for storing mineral fuel oil FO, that it is provided with a fuel oil supply line 72 for supplying the mineral fuel oil FO to the junction A with the biofuel supply line 42, that the junction A where the mineral fuel oil FO and the biodiesel fuel oil BO are mixed is located upstream of the settling tank 11A, that the purifier inlet line 12 is composed of a settling tank upstream purifier inlet line 12c and a settling tank downstream purifier inlet line 12d, and that the settling tank 11A is used as a tank for storing mixed fuel oil MO.

[0087] The storage tank 71 (first tank) is installed at the most upstream portion of the fuel oil supply line 72 . The fuel oil supply line 72 is provided with a fuel supply pump 73, a fuel flow meter 74, and a shutoff valve 75. The fuel oil supply line 72 is connected from the storage tank 71 to the junction A via the fuel supply pump 73, the fuel flow meter 74, and the shutoff valve 75. The fuel supply pump 73 is a pump for sending the mineral fuel oil FO in the fuel oil supply line 72 to the junction A side.

[0088] The fuel flow meter 74 is a flow meter for measuring the flow rate of the mineral fuel oil FO sent from the storage tank 71 to the junction A side. The shutoff valve 75 is a valve for allowing the mineral fuel oil FO in the storage tank 71 to flow to the junction A side or for blocking the flow.

[0089] Similar to the biofuel supply line 42 of the first embodiment (see FIG. 2), the biofuel supply line 42 is provided with a biodiesel tank 41 (second tank), a biofuel supply pump 43, a biofuel supply flow meter 44, and a shutoff valve 45. The biofuel supply line 42 is connected from the biodiesel tank 41 to the junction A via the biofuel supply pump 43, the biofuel supply flow meter 44, and the shutoff valve 45.

[0090] In the fuel oil mixing system 10A, a mixed fuel oil MO is produced by mixing a mineral fuel oil FO and a biodiesel fuel oil BO at a confluence A. A purifier inlet line 12 that supplies the mixed fuel oil MO to a fuel oil purifier 21 is provided downstream of the confluence A. The purifier inlet line 12 is made up of a settling tank upstream purifier inlet line 12c from the confluence A to the settling tank 11A, the settling tank 11A, and a settling tank downstream purifier inlet line 12d from the settling tank 11A to the fuel oil purifier 21. The settling tank upstream purifier inlet line 12c is a flow path for sending the mixed fuel oil MO generated at the junction A to the mixed fuel oil inlet 11Ac of the settling tank 11A. A purifier fuel supply pump 13 is provided in the purifier inlet line 12d downstream of the settling tank.

[0091] Thus, the fourth embodiment, as shown in FIG. 13, is a fuel oil mixing system 10A for producing a mixed fuel oil MO by mixing mineral fuel oil FO with biodiesel fuel oil BO, and for producing purified fuel oil CO by purifying the mixed fuel oil MO, and includes a fuel oil purifier 21 arranged on board a ship, a storage tank 71 for storing the mineral fuel oil FO, and a second tank 41 for storing the biodiesel fuel oil BO, and the mixed fuel oil MO produced by mixing the mineral fuel oil FO in the storage tank 71 and the biodiesel fuel oil BO in the second tank 41 is supplied to the fuel oil purifier 21.

[0092] The fuel oil mixing system 10A has a fuel oil purifier 21 inside the hull, so that the mixed fuel oil MO can be further mixed. In addition, the fuel oil purifier 21 of the fuel oil mixing system 10A can purify the mixed fuel oil MO. In this way, the fuel oil mixing system 10A can efficiently mix the mineral fuel oil and the biodiesel fuel oil automatically or manually, and can remove the sludge generated by the mixing. The purified fuel oil CO obtained by purifying the mixed fuel oil MO can be supplied to the ship's engine or auxiliary machinery for use.

[0093] The fuel oil mixing system 10A includes a settling tank 11A (mixed fuel oil storage tank) that stores the mixed fuel oil MO. According to this configuration, a predetermined amount of mixed fuel oil MO can be stored at all times, so that clean fuel oil CO can be produced even during inspection of the upstream side of the settling tank 11A.

[0094] In addition, since the fuel oil mixing system 10A includes a storage tank 71, it is possible to store a desired amount of mineral fuel oil FO for producing the mixed fuel oil MO.

[0095] [First Modification] The present invention is not limited to the first to fourth embodiments described above, and various modifications and changes are possible within the scope of the technical concept thereof. It goes without saying that the present invention also covers such modifications and changes. FIG. 4 is a schematic diagram showing a first modified example of the fuel oil mixing system and fuel oil mixing method according to the present invention (more specifically, a modified example of the fuel oil mixing system 1A of the second embodiment shown in FIG. 2).

[0096] The fuel oil mixing system 1C shown in FIG. 4 may include a first oil heater H1 (oil heater) in the purifier inlet line 12 for heating the mineral fuel oil FO or the mixed fuel oil MO.

[0097] The first oil heater H1 (oil heater) is provided in the purifier inlet line 12 (downstream purifier inlet line 12b) downstream of the junction a (between the junction a and the fuel oil switching means 16 in FIG. 4). That is, the first oil heater H1 may be provided in the purifier inlet line 12 upstream of the fuel oil switching means 16.

[0098] If the first oil heater H1 is disposed between the junction a and the fuel oil switching means 16, the mixed fuel oil MO can be heated.

[0099] According to this configuration, the mineral fuel oil FO and the mixed fuel oil MO can be heated in the first oil heater H1 (oil heater) to reduce the viscosity of the mineral fuel oil FO and the mixed fuel oil MO, thereby increasing the efficiency of separation of solids and / or moisture in the fuel oil purifier 21.

[0100] [Second modified example] FIG. 5 is a schematic configuration diagram showing a second modified example of the fuel oil mixing system and fuel oil mixing method according to the present invention (more specifically, a modified example of the fuel oil mixing system 1B of the third embodiment shown in FIG. 3).

[0101] A fuel oil mixing system 1D of a second modified example shown in Fig. 5 is a modified example of the fuel oil mixing system 1B of the third embodiment shown in Fig. 3. The fuel oil mixing system 1D may include a second oil heater H2 (oil heater) for heating the mineral fuel oil FO in the purifier inlet line 12 (downstream purifier inlet line 12b) between the purifier bypass line branch point b and the mineral fuel oil switching means 16B.

[0102] Specifically, the fuel oil mixing system 1D may be provided with a second oil heater H2 (oil heater) for heating the mineral fuel oil FO on the upstream side of the mineral fuel oil switching means 16B of the purifier inlet line 12.

[0103] With this configuration, the mineral fuel oil FO can be heated in the second oil heater H2, thereby reducing the viscosity of the mineral fuel oil FO and increasing the efficiency of separation of solids and moisture in the fuel oil purifier 21.

[0104] [Third Modification] FIG. 6 is a schematic diagram showing a third modified example of the fuel oil mixing system and fuel oil mixing method according to the present invention (more specifically, a modified example of the fuel oil mixing system 1A of the second embodiment shown in FIG. 2).

[0105] A fuel oil mixing system 1E of a third modification shown in Fig. 6 is a modification of the fuel oil mixing system 1A of the second embodiment shown in Fig. 2. In the fuel oil mixing system 1A, a three-way valve is used as the fuel oil switching means 16, but as in the fuel oil mixing system 1E, the fuel oil switching means 16 may be configured by combining two on-off valves 161, 162.

[0106] In this case, one of the on-off valves 161 is installed in the purifier inlet line 12 downstream of the purifier second bypass line branch point c between the purifier inlet line 12 and the first purifier return line 17A (between the purifier second bypass line branch point c and the inlet 21a of the fuel oil purifier 21). The other on-off valve 162 is installed in the first purifier return line 17A downstream of the purifier second bypass line branch point c (between the purifier second bypass line branch point c and the purifier bypass line junction point d of the first purifier return line 17A).

[0107] With this configuration, a commercially available two-way shutoff valve can be used, and it is possible to flexibly accommodate changes in the materials of the piping and valves.

[0108] [Fourth Modification] FIG. 7 is a schematic diagram showing a fourth modified example of the fuel oil mixing system and fuel oil mixing method according to the present invention (more specifically, a modified example of the fuel oil mixing system 1B of the third embodiment shown in FIG. 3).

[0109] A fourth modified fuel oil mixing system 1F shown in Fig. 7 is a modified version of the fuel oil mixing system 1B of the third embodiment shown in Fig. 3. In the fuel oil mixing system 1B, the mineral fuel oil switching means 16B is a three-way valve, but it may be configured with two switching valves 16B1 and 16B2, which are two-way valves, as in the fuel oil mixing system 1F.

[0110] In this case, the switching valve 16B1 is installed between the purifier second bypass line branch point c of the upstream purifier inlet line 12a and the junction point a. Also, the switching valve 16B2 is installed between the purifier second bypass line branch point c of the downstream second purifier return line 17B and the purifier bypass line junction point d.

[0111] Even with this configuration, the switching valves 16B1 and 16B2 of the fuel oil mixing system 1F have the same effect as the mineral fuel oil switching means 16B consisting of a three-way valve of the fuel oil mixing system 1B. In other words, when the fuel oil purifier 21 is in a state where it can pass the liquid, it passes the liquid, and otherwise it switches to a line that returns the liquid to the first tank 11, thereby minimizing the load fluctuation of the second oil heater H2 (see FIG. 5) without stopping the passage of the liquid to the second oil heater H2 (see FIG. 5).

[0112] [Fifth Modification] FIG. 8 is a schematic configuration diagram showing a fifth modified example of the fuel oil mixing system and fuel oil mixing method according to the present invention (more specifically, a modified example of the fuel oil mixing system 1B of the third embodiment shown in FIG. 3).

[0113] A fuel oil mixing system 1G of a fifth modified example shown in Fig. 8 is a modified example of the fuel oil mixing system 1B of the third embodiment shown in Fig. 3. The fuel oil mixing system 1G may be provided with a biodiesel fuel oil switching means 47 consisting of one shutoff valve in the biodiesel return line 46, similar to the fuel oil mixing system 1A of the second embodiment (see Fig. 2).

[0114] According to this configuration, the fuel oil mixing system 1G can circulate the biodiesel fuel oil BO in the biofuel supply line 42 to the biodiesel return line 46 at an appropriate time by opening and closing the biodiesel fuel oil switching means 47. In addition, by adjusting the degree of opening of the biodiesel fuel oil switching means 47, the flow rate of the biodiesel fuel oil BO circulating through the biodiesel return line 46 can be adjusted.

[0115] [Sixth Modification] Figure 9 is a schematic diagram showing the main parts of a sixth variant of the fuel oil mixing system and fuel oil mixing method of the present invention (more specifically, a variant of the fuel oil mixing system 1A of the second embodiment shown in Figure 2 and the fuel oil mixing system 1G of the fifth variant shown in Figure 8).

[0116] A fuel oil mixing system 1H of a sixth modified example shown in Fig. 9 is a modified example of the fuel oil mixing system 1A of the second embodiment shown in Fig. 2 and the fuel oil mixing system 1G of a fifth modified example shown in Fig. 8. The fuel oil mixing system 1H may include biodiesel fuel oil switching means 47A, 47B downstream of a branch point e between the biofuel supply line 42 and the biodiesel return line 46.

[0117] One biodiesel fuel oil switching means 47A is composed of a shutoff valve similar to the biodiesel fuel oil switching means 47 of the second embodiment (see FIG. 2) and the biodiesel fuel oil switching means 47 of the fifth modified example (see FIG. 8), and may be provided at an appropriate position in the biodiesel return line 46. The other biodiesel fuel oil switching means 47B is a shutoff valve provided downstream of branch point e and near the biofuel supply flow meter 44, or upstream (not shown).

[0118] According to the fuel oil mixing system 1H, by opening and closing the switching valves (biodiesel fuel oil switching means 47A, 47B) constituting the biodiesel fuel oil switching means 47, the biodiesel fuel oil BO can be circulated to the biodiesel return line 46 or switched to flow into the biofuel supply line 42. In addition, by adjusting the degree of opening of the biodiesel fuel oil switching means 47A, 47B, the flow rate of the biodiesel fuel oil BO flowing to the biodiesel return line 46 side and the junction a (see FIG. 8) side can be adjusted.

[0119] [Seventh Variation] FIG. 10 is a schematic diagram showing a seventh modified example of the fuel oil mixing system and fuel oil mixing method according to the present invention (more specifically, a modified example of the biofuel supply line 42 of the fuel oil mixing system 1A of the second embodiment shown in FIG. 2).

[0120] A fuel oil mixing system 1I of a seventh modification shown in Fig. 10 is a modification of the biofuel supply line 42 of the fuel oil mixing system 1A of the second embodiment shown in Fig. 2. The fuel oil mixing system 1I may include an agent supplying device 5 for mixing an agent D with the biodiesel fuel oil BO in the biofuel supply line 42.

[0121] More specifically, the fuel oil mixing system 1I includes a biofuel supply line 42 for supplying the biodiesel fuel oil BO in the second tank 41 to the purifier inlet line 12, and a chemical supply device 5 for mixing a chemical D containing at least one of an antioxidant and a pour point depressant with the biodiesel fuel oil BO flowing through the biofuel supply line 42, and the chemical supply device 5 may include a chemical tank 51 for storing the chemical D, a chemical supply line 52 for supplying the chemical D in the chemical tank 51 to the biofuel supply line 42, and a chemical supply pump 53 provided in the chemical supply line 52.

[0122] As shown in FIG. 10, the upstream side of the drug supply line 52 is connected to the lower part of the drug tank 51 . For example, when the biodiesel return line 46 has a switching means 47 for biodiesel fuel oil (see Figs. 2 to 8), the following two types of agent supplying methods can be implemented. (1) When biodiesel fuel oil BO is being supplied to mineral fuel oil FO, it becomes possible to supply agent D. (2) When biodiesel fuel oil BO is not being supplied to the mineral fuel oil FO, the biodiesel fuel oil BO in the biofuel supply line 42 can be returned to the second tank 41 via the biodiesel return line 46, making it possible to supply the chemical D while circulating the biodiesel fuel oil BO.

[0123] According to the fuel oil mixing system 1I, the chemical D containing at least one of an antioxidant and a pour point depressant can be mixed with the biodiesel fuel oil BO in the biofuel supply line 42 by the chemical supply device 5. That is, according to the fuel oil mixing system 1I, it is possible to prevent oxidation of the biodiesel fuel oil BO and hardening (reduction in fluidity) at low temperatures.

[0124] [Eighth Modification] FIG. 11 is a schematic diagram showing an eighth modified example of the fuel oil mixing system and fuel oil mixing method according to the present invention (more specifically, a modified example of the fuel oil mixing system 1B of the second embodiment shown in FIG. 3).

[0125] A fuel oil mixing system 1J of an eighth modified example shown in Fig. 11 is a modified example of the fuel oil mixing system 1B of the third embodiment shown in Fig. 3. The fuel oil mixing system 1J may be provided with a chemical supply device 5 in the biofuel supply line 42, similar to the fuel oil mixing system 1I of the seventh modified example (see Fig. 10).

[0126] The drug supply device 5 may also include a drug tank 51 , a drug supply line 52 , and a drug supply pump 53 .

[0127] The fuel oil mixing system 1J has the same effects as the fuel oil mixing system 1I of the seventh modified example (see FIG. 10).

[0128] [Ninth Variation] Figure 12 is a schematic diagram showing the essential parts of a ninth variant of the fuel oil mixing system and fuel oil mixing method of the present invention (more specifically, a variant of the agent supply line 52 of the fuel oil mixing system 1J of the eighth variant shown in Figure 11).

[0129] A fuel oil mixing system 1K of a ninth modified example shown in FIG. 12 may include an agent supplying device 5 in the biodiesel return line 46.

[0130] The chemical supply device 5 of the fuel oil mixing system 1K includes a chemical tank 51, a chemical supply line 52, and a chemical supply pump 53.

[0131] More specifically, the fuel oil mixing system 1K includes an agent supplying device 5 for mixing an agent D containing at least one of an antioxidant and a pour point depressant with the biodiesel fuel oil BO flowing through the biodiesel return line 46. The agent supplying device 5 may include an agent tank 51 that stores the agent D, an agent supplying line 52 for supplying the agent D in the agent tank 51 to the biodiesel return line 46, and an agent supplying pump 53 provided on the agent supplying line 52.

[0132] According to the fuel oil mixing system 1K, since the agent supplying device 5 is provided, it is possible to prevent oxidation of the biodiesel fuel oil BO by the antioxidant, and to prevent hardening at low temperatures by the pour point depressant.

[0133] [Tenth Modification] FIG. 14 is a schematic diagram showing a tenth modified example of the fuel oil mixing system and fuel oil mixing method according to the present invention (more specifically, a modified example of the fuel oil mixing system 10A of the fourth embodiment shown in FIG. 13).

[0134] The fuel oil mixing system 10B shown in Figure 14 differs from the fuel oil mixing system 10A of the fourth embodiment (see Figure 13) in that it has a biodiesel return line 46, a fuel oil return line 76, a fuel oil switching means 16C, a third purifier return line 17C (purifier return line), a purifier bypass line 18, and a flow rate adjustment means 19A for mixed fuel oil.

[0135] Like the fuel oil mixing system 1A of the second embodiment, the fuel oil mixing system 10B has a biodiesel return line 46. The biodiesel return line 46 is a piping path that leads from the biofuel supply line 42 to the biodiesel tank 41 (second tank).

[0136] When the biodiesel fuel oil switching means 45A is closed and the biodiesel fuel oil switching means 47 is open, and the biodiesel fuel oil BO is driven, the biodiesel fuel oil BO flows out from the biodiesel fuel oil discharge port 41a of the biodiesel tank 41 into the biodiesel supply line 42, and can be returned to the biodiesel tank 41 via the biodiesel fuel oil supply pump 43, the biodiesel return line 46, the biodiesel fuel oil switching means 47, and the biodiesel fuel oil return port 41b in the biofuel supply line 42.

[0137] The biodiesel fuel oil switching means 47 and the biodiesel fuel oil switching means 45A are each electrically connected to a control device (not shown) and controlled by the control device (not shown). The biodiesel fuel oil switching means 45A may be installed between the biodiesel return line branch point e of the biofuel supply line 42 and the biofuel supply flow meter 44.

[0138] The fuel oil mixing system 10B also has a fuel oil return line 76 that branches off from the fuel oil supply line 72 and leads to the storage tank 71 (first tank). A branch point g (fuel oil return line branch point g) of the fuel oil return line 76 is provided between the fuel supply pump 73 and the fuel flow meter 74. The downstream side of the fuel oil return line 76 is connected to a fuel oil inlet 71b provided at the top of the storage tank 71 via a fuel oil switching means 77.

[0139] Therefore, when the fuel supply pump 73 is driven with the shutoff valve 75 closed and the fuel oil switching means 77 open, the mineral fuel oil FO flows out from the fuel oil discharge port 71a of the storage tank 71 into the fuel oil supply line 72 and can be returned to the storage tank 71 via the fuel supply pump 73, the fuel oil return line 76, the fuel oil switching means 77, and the fuel oil inlet 71b. The fuel oil switching means 77 and the shutoff valve 75 are each electrically connected to a control device (not shown) and controlled by the control device (not shown).

[0140] Note that the fuel oil switching means 77 and the shut-off valve 75 may be manual. Further, the shut-off valve 75 may be installed between the fuel oil return line branch point g of the fuel oil supply line 72 and the fuel flow meter 74.

[0141] The fuel oil switching means 16C is composed of, for example, a three-way valve (switching valve). The fuel oil switching means 16C is electrically connected to a control device (not shown) and is controlled by the control device (not shown). When the fuel oil cleaner 21 is stopped (i.e., when no liquid is flowing through the fuel oil cleaner 21), the fuel oil switching means 16C is configured to flow to the third cleaner return line 17C side. Note that the fuel oil switching means 16C may be a three-way valve that switches the mixed fuel oil MO in the upstream cleaner inlet line 12a to flow to either the third cleaner return line 17C side or the fuel oil cleaner 21 side, and its installation position, installation state, etc. may be changed as appropriate.

[0142] When operating the fuel oil cleaner 21, first, start the cleaner fuel supply pump 13 and flow the mixed fuel oil MO into the cleaner inlet line 12 (downstream cleaner inlet line 12b). At the same time, start the fuel oil cleaner 21 and increase its rotational speed. All of the mixed fuel oil MO discharged from the cleaner fuel supply pump 13 returns to the setting ring tank 11A through the third cleaner return line 17C. When the fuel oil cleaner 21 is in a state where liquid can flow through it, switch the fuel oil switching means 16C to the fuel oil cleaner 21 side, and start the cleaning process by flowing the mixed fuel oil MO through the fuel oil cleaner 21. Note that the fuel oil cleaner 21 may be of a specification that allows for manual operation.

[0143] The third cleaner return line 17C is a pipeline for returning the mixed fuel oil MO from the cleaner inlet line 12 downstream of the cleaner bypass line branch point b to the setting ring tank 11A. The upstream side of the third cleaner return line 17C is connected to the fuel oil switching means 16C, and the downstream side is connected to the mixed fuel oil inlet 11Ab of the setting ring tank 11A.

[0144] The purifier bypass line 18 is a piping path connecting the upstream purifier inlet line 12a of the purifier inlet line 12 and the third purifier return line 17C (purifier return line). The purifier bypass line branch point b is a branch point between the upstream purifier inlet line 12a and the purifier bypass line 18. The purifier bypass line branch point b is disposed between the purifier fuel supply pump 13 provided on the purifier inlet line 12 (upstream purifier inlet line 12a) and the purifier fuel flow meter 14. The purifier bypass line junction point d is a junction point between the third purifier return line 17C and the purifier bypass line 18.

[0145] The purifier bypass line 18 is provided with a flow rate adjusting means 19A for the mixed fuel oil. The mixed fuel oil flow rate adjusting means 19A is composed of a regulating valve that adjusts the flow rate of the mixed fuel oil MO flowing through the purifier bypass line 18.

[0146] Thus, the fuel oil mixing system 10B shown in Figure 14 includes a purifier inlet line 12 for supplying the mixed fuel oil MO in the settling tank 11A to the fuel oil purifier 21, and a third purifier return line 17C (purifier return line) that runs from the purifier inlet line 12 to the settling tank 11A. By providing the third purifier return line 17C, the excess mixed fuel oil MO on the purifier inlet line 12 can be adjusted to supply an optimal flow rate of mixed fuel oil MO to the fuel oil purifier 21.

[0147] The fuel oil mixing system 10B also includes a purifier bypass line 18 for flowing the mixed fuel oil MO in the purifier inlet line 12 to the third purifier return line 17C. The fuel oil mixing system 10B also includes a fuel oil switching means 16C downstream of the branch point b for switching the mixed fuel oil MO in the purifier inlet line 12 to flow through the third purifier return line 17C. By providing the fuel oil switching means 16C, the flow rate of the fuel oil supplied to the fuel oil purifier 21 can be adjusted to an appropriate amount.

[0148] The fuel oil mixing system 10B may also include a mixer downstream of the purifier bypass line branch point b (branch point). By providing a mixer (not shown) downstream of the branch point b of the purifier bypass line, the biodiesel fuel oil BO in the purifier inlet line 12 can be further mixed.

[0149] The fuel oil mixing system 10B also includes a purifier bypass line 18 for flowing at least a portion of the mixed fuel oil MO in the purifier inlet line 12 to the third purifier return line 17C (purifier return line). The purifier bypass line 18 includes a mixed fuel oil flow rate adjustment means 19A for adjusting the amount of the mixed fuel oil MO flowing to the third purifier return line 17C side. By providing the mixed fuel oil flow rate adjusting means 19A, the flow rate of the mixed fuel oil MO supplied to the fuel oil purifier 21 can be adjusted to an appropriate amount.

[0150] In addition, the fuel oil mixing system 10B is equipped with a flow rate control means 19A for mixed fuel oil on the discharge side of the purifier fuel supply pump 13 provided in the purifier inlet line 12, so that the flow rate of the mixed fuel oil MO flowing from the purifier inlet line 12 to the fuel oil purifier 21 can be adjusted.

[0151] The biodiesel fuel oil switching means 45A shown in FIG. 14 may be provided between the biodiesel return line branch point e and the biofuel supply flow meter 44. In addition, the biodiesel fuel oil switching means 47 consisting of a shutoff valve may be a switching valve. The biodiesel fuel oil switching means 47 consisting of a shutoff valve can achieve the same effects even if it is replaced with a switching valve.

[0152] The fuel oil switching means 16C shown in Figure 14 only needs to have the function of switching the mixed fuel oil MO in the purifier inlet line 12 (upstream purifier inlet line 12a) to flow to either the third purifier return line 17C side or the fuel oil purifier 21 side, and the function, structure, type, etc. of the valve are not particularly limited.

[0153] [Eleventh Modification] FIG. 15 is a schematic diagram showing an eleventh modified example of the fuel oil mixing system and fuel oil mixing method according to the present invention.

[0154] A fuel oil mixing system 10C shown in FIG. 15 includes a first oil heater H1 (oil heater) for heating the mixed fuel oil MO in the purifier inlet line 12, similar to the fuel oil mixing system 1C shown in FIG.

[0155] The first oil heater H1 (oil heater) is provided between the purifier bypass line branch point b of the downstream purifier inlet line 12b and the fuel oil switching means 16C. In addition, the fuel oil switching means 16C may be a three-way valve that switches the mixed fuel oil MO in the upstream purifier inlet line 12a to flow either to the third purifier return line 17C side or the fuel oil purifier 21 side, and its installation position, installation state, etc. may be changed as appropriate.

[0156] By providing the first oil heater H1, the mixed fuel oil MO can be heated, which reduces the viscosity of the mixed fuel oil MO and increases the efficiency of separation of solids and / or water in the fuel oil purifier 21.

[0157] [Twelfth Modification] FIG. 16 is a schematic diagram showing a twelfth modified example of the fuel oil mixing system and the fuel oil mixing method according to the present invention.

[0158] A fuel oil mixing system 10D shown in Fig. 16 is a modified example of the fuel oil mixing system 10B shown in Fig. 14. The fuel oil switching means 16C of the fuel oil mixing system 10B was a three-way valve, but the fuel oil switching means 16E of the fuel oil mixing system 10D is configured by combining two switching valves 161E, 162E.

[0159] One of the switching valves 161E is installed in the downstream purifier inlet line 12b downstream of the purifier second bypass line branch point c (between the purifier second bypass line branch point c and the inlet 21a of the fuel oil purifier 21).

[0160] In addition, the other switching valve 162E is installed in the third purifier return line 17C downstream of the purifier second bypass line branch point c (between the purifier second bypass line branch point c and the purifier bypass line junction point d of the third purifier return line 17C).

[0161] In addition, the switching valve 161E and the switching valve 162E may consist of two switching valves that can switch the mixed fuel oil MO in the upstream purifier inlet line 12a to flow either to the third purifier return line 17C side or to the fuel oil purifier 21 side, and their installation positions, installation state, etc. may be changed as appropriate.

[0162] Since switching valves (on-off valves) are readily available, by configuring the fuel oil switching means 16E by combining switching valves, it is possible to flexibly respond to changes in piping and the like.

[0163] [13th Variation] FIG. 17 is a schematic diagram showing a thirteenth modified example of the fuel oil mixing system and the fuel oil mixing method according to the present invention.

[0164] A fuel oil mixing system 10E shown in Fig. 17 is a modified example of the fuel oil mixing system 10B shown in Fig. 14. The fuel oil mixing system 10E includes an agent supplying device 5. The agent supplying device 5 supplies an agent D to the biodiesel fuel oil BO in the biofuel supply line 42.

[0165] Specifically, the chemical D includes at least one of an antioxidant and a pour point depressant. The chemical supply device 5 includes a chemical tank 51 for storing the chemical D, a chemical supply line 52 for supplying the chemical D in the chemical tank 51 to the biofuel supply line 42, and a chemical supply pump 53 provided in the chemical supply line 52.

[0166] As shown in FIG. 17, the upstream side of the drug supply line 52 is connected to the lower part of the drug tank 51.

[0167] For example, when the biodiesel return line 46 has a switching means 47 for biodiesel fuel oil, the following two types of agent supply methods can be implemented. (1) When biodiesel fuel oil BO is being supplied to mineral fuel oil FO, agent D is supplied. (2) When biodiesel fuel oil BO is not being supplied to the mineral fuel oil FO, the agent D is supplied while circulating the biodiesel fuel oil BO in the second tank 41 via the biofuel supply line 42 and the biodiesel return line 46.

[0168] According to the fuel oil mixing system 10E, the chemical D can be mixed with the biodiesel fuel oil BO in the biofuel supply line 42 by the chemical supply device 5. That is, according to the fuel oil mixing system 10E, it is possible to prevent oxidation of the biodiesel fuel oil BO and hardening (reduction in fluidity) at low temperatures.

[0169] [14th Variation] FIG. 18 is a schematic diagram showing a fourteenth modified example of the fuel oil mixing system and the fuel oil mixing method according to the present invention.

[0170] 18 includes two each of the biodiesel tank 41 (second tank), the storage tank 71 (first tank), and the fuel oil purifier 21. Note that three or more each of the biodiesel tank 41, the storage tank 71, and the fuel oil purifier 21 may be provided.

[0171] A plurality of biodiesel tanks 41 are disposed upstream of a biofuel supply pump 43 . In addition, the multiple storage tanks 71 are disposed upstream of the fuel supply pump 73 . The fuel oil purifiers 21 are arranged in parallel. A purifier fuel supply pump 13 is arranged in a purifier inlet line 12d downstream of the settling tank, which extends from the settling tank 11A to each of the fuel oil purifiers 21.

[0172] By installing multiple biodiesel tanks 41 and multiple storage tanks 71, it is possible to store large amounts of mineral fuel oil FO and biodiesel fuel oil BO in separate tanks on board the ship. This makes it convenient because even if a problem occurs in one tank, it is possible to use the other tanks to supply fuel oil. In addition, by installing multiple fuel oil purifiers 21, the purification processing capacity of the mixed fuel oil MO on board can be improved. Even if one fuel oil purifier 21 breaks down, the other fuel oil purifiers 21 can be used to purify the mixed fuel oil MO.

[0173] [15th Variation] FIG. 19 is a schematic diagram showing a fifteenth modified example of the fuel oil mixing system and fuel oil mixing method according to the present invention.

[0174] The fuel oil mixing system 10G shown in Fig. 19 is a combination of the fuel oil mixing system 10F shown in Fig. 18 and the configuration of the fuel oil mixing system 10B shown in Fig. 14. That is, the fuel oil mixing system 10G shown in Fig. 19 is provided with a purifier bypass line 18 equipped with a mixed fuel oil flow rate adjustment means 19A, and a third purifier return line 17C equipped with a fuel oil switching means 16C.

[0175] In the fuel oil mixing system 10G, fuel oil switching means 16C, 16C are arranged in each of the multiple purifier inlet lines 12 corresponding to the multiple fuel oil purifiers 21. In this way, the mixed fuel oil MO supplied to each fuel oil purifier 21 can be adjusted to an optimal flow rate.

[0176] In addition, the fuel oil switching means 16C, 16C may be any three-way valve that can switch the mixed fuel oil MO in the upstream purifier inlet line 12a to flow either to the third purifier return line 17C side or to the fuel oil purifier 21 side, and its installation position, installation state, etc. may be changed as appropriate.

[0177] [16th Variation] FIG. 20 is a schematic diagram showing a sixteenth modified example of the fuel oil mixing system and the fuel oil mixing method according to the present invention.

[0178] The fuel oil mixing system 10H shown in Fig. 20 is a modified example of the fuel oil mixing system 10G shown in Fig. 19, and is provided with oil heaters (second oil heaters H2, H2) for heating the mixed fuel oil MO in the purifier inlet lines 12 (upstream purifier inlet lines 12a of each). Downstream of the second oil heaters H2, H2, fuel oil switching means 16C, 16C each consisting of a three-way valve are provided. According to this configuration, the mixed fuel oil MO can be heated by the second oil heater H2, so that the viscosity of the mixed fuel oil MO can be reduced and the efficiency of separation of solids and moisture in the fuel oil purifier 21 can be increased.

[0179] In addition, the fuel oil switching means 16C, 16C may be any three-way valve that can switch the mixed fuel oil MO in the upstream purifier inlet line 12a to flow either to the third purifier return line 17C side or to the fuel oil purifier 21 side, and its installation position, installation state, etc. may be changed as appropriate.

[0180] [17th Variation] FIG. 21 is a schematic diagram showing a seventeenth modified example of the fuel oil mixing system and fuel oil mixing method according to the present invention.

[0181] A fuel oil mixing system 10I shown in FIG. 21 is a modified example of the fuel oil mixing system 10D shown in FIG. 16, and includes a fuel oil switching means 16E constituted by two switching valves 161E and 162E each consisting of a two-way valve.

[0182] The switching valves 161E, 162E may be manually switched to supply the mixed fuel oil MO to the fuel oil purifier 21 of a manual type.

[0183] In addition, the switching valves 161E, 162E of the fuel oil switching means 16E, 16E may be located on the third purifier return line 17C side of the purifier second bypass line branch point c and on the downstream purifier inlet line 12b, and their installation positions, installation state, etc. may be changed as appropriate.

[0184] [18th Variation] FIG. 22 is a schematic diagram showing an 18th modified example of the fuel oil mixing system and fuel oil mixing method according to the present invention.

[0185] The fuel oil mixing system 10J shown in FIG. 22 includes a chemical supply device 5, similar to the fuel oil mixing system 10E shown in FIG.

[0186] The chemical supply device 5 is a device for mixing a chemical D with the biodiesel fuel oil BO flowing through the biofuel supply line 42. The chemical supply device 5 includes a chemical tank 51 that stores the chemical D, a chemical supply line 52 for supplying the chemical D in the chemical tank 51 to the biofuel supply line 42, and a chemical supply pump 53 provided on the chemical supply line 52.

[0187] 22, the upstream side of the chemical supply line 52 is connected to the lower part of the chemical tank 51. It is preferable that the junction point f of the chemical supply line 52 with the biofuel supply line 42 is located upstream of the branch point e of the biofuel supply line 42 and the biodiesel return line 46.

[0188] In addition, the drug supply device 5 is not limited to being installed at the junction f, but may also be installed between the biodiesel fuel oil switching means 47 of the biodiesel return line 46 and the biodiesel fuel oil return port 41b of the biodiesel tank 41.

[0189] According to the fuel oil mixing system 10J, the biodiesel fuel oil BO can be mixed with the agent D. This makes it possible to prevent oxidation of the biodiesel fuel oil BO and hardening (reduction in fluidity) at low temperatures.

[0190] [Other variations] The first oil heater H1 (oil heater) and the second oil heater H2 (oil heater) may be installed in the first tank 11. In addition, an oil heater may be provided in a pipe that transfers the mineral fuel oil FO from a fuel oil storage tank (not shown) to the first tank 11.

[0191] 10 to 12 is connected to the biofuel supply line 42 or the biodiesel return line 46, this may be changed as appropriate. For example, the chemical supply device 5 may be installed in the second tank 41.

[0192] Although not shown, a mixing device such as a static mixer may be installed in the piping downstream of the junction a of the purifier inlet line 12 and the biofuel supply line 42 and upstream of the fuel oil purifier 21. In this way, the mineral fuel oil FO and the biodiesel fuel oil BO can be mixed more reliably.

[0193] The fuel oil purifier 21 may be installed at any location as long as it ensures the mixing of the mineral fuel oil FO and the biodiesel fuel oil BO. The fuel oil purifier 21 may be installed at the junction a, A where the mineral fuel oil FO and the biodiesel fuel oil BO are mixed, the upstream purifier inlet line 12a, or the settling tank upstream purifier inlet line 12c. By doing so, the overall length of the piping in the fuel oil mixing systems 1, 1A to 1K, 10A to 10S can be shortened, thereby making the system more compact.

[0194] In the first embodiment, the fuel oil purifier 21 is used to separate and purify solids contained in the oil by centrifugal separation as an example of an oil purification means, but the oil may be purified by filtration. Any method such as pressure filtration, vacuum filtration, reduced pressure filtration, and gravity filtration may be used as the filtration method. For example, filter paper, filter cloth, filter net, ceramic filter, microfiltration membrane (MF membrane), ultrafiltration membrane (UF membrane), hollow fiber membrane, flat membrane, etc. may be used as the filtering material.

[0195] In addition, a plurality of fuel oil purifiers may be installed in combination, such as a combination of a centrifuge and a filter, or the purification means may be arranged in series or in parallel. The centrifuge and filter may be configured, for example, as a centrifuge + centrifuge, a centrifuge + filter, or a centrifuge + centrifuge + filter.

[0196] In addition, the general purpose of the first tank 11 (settling tank) is to heat the mineral fuel oil FO transferred from a fuel oil storage tank (not shown) to a constant temperature using a tank heater (not shown) installed in the first tank 11, reduce the viscosity, and leave it to stand, thereby allowing the solids and moisture in the mineral fuel oil FO to settle naturally and to be drained from the bottom of the first tank 11.

[0197] Furthermore, when manufacturing the fuel oil mixing system 1 by modifying an existing fuel oil mixing equipment, the flow rate is lower if the fuel purification equipment is modified than if the fuel transfer equipment from the fuel oil storage tank (not shown) is modified, and smaller components such as piping equipment and flow meters can be used. [Explanation of symbols]

[0198] 1,1A~1K,10A~10J Fuel oil mixing system 5. Drug supply device 11 First tank (settlement tank) 11A Settling tank (mixed fuel oil storage tank) 12 Purifier inlet line 13 Purifier fuel supply pump 16,16C,16D,16E Fuel oil switching means 16B Mineral fuel oil switching means 16B1, 16B2 Switching valve 17 Purifier return line 17A First purifier return line (purifier return line) 17B Second purifier return line (purifier return line) 17C 3rd purifier return line (purifier return line) 18 Purifier bypass line 19 Flow control means for mineral fuel oil 19A Flow rate adjustment means for mixed fuel oil 21 Fuel oil purifier 22 Fuel purification oil line 31 Service Tank 32 Overflow pipe 41 Second tank (biodiesel fuel oil tank) 42 Biofuel Supply Line 43 Biofuel supply pump 44 Biofuel Supply Flow Meter 45 Shut-off valve 45A Biodiesel Fuel Oil Switching Device 46 Biodiesel return line 47 Biodiesel fuel oil switching means 47A, 47B Biodiesel fuel oil switching means (switching valve) 51 Chemical tank 52 Drug Supply Line 53 Drug delivery pump 71 Storage Tank (First Tank) 161,162 On-off valve a confluence b Purifier bypass line branch point (branch point) BO Biodiesel Fuel Oil CO clean fuel oil D. Drugs FO Mineral fuel oil H1 1st oil heater (oil heater) H2 Second oil heater (oil heater) MO Mixed fuel oil

Claims

1. A fuel oil mixing system for producing a purified fuel oil by purifying a mixed fuel oil obtained by mixing a mineral fuel oil with a biodiesel fuel oil, comprising: A fuel oil purifier installed on board the ship; A first tank for storing the mineral fuel oil; A second tank for storing the biodiesel fuel oil; A mixed fuel oil storage tank for storing a mixed fuel oil produced by mixing the mineral fuel oil in the first tank and the biodiesel fuel oil in the second tank; A purifier inlet line for supplying the mixed fuel oil in the mixed fuel oil storage tank to the fuel oil purifier; a purifier return line from the purifier inlet line to the mixed fuel oil storage tank; Fuel oil mixing system.

2. A fuel oil mixing system for producing a purified fuel oil by purifying a mixed fuel oil obtained by mixing a mineral fuel oil with a biodiesel fuel oil, comprising: A fuel oil purifier installed on board the ship; A first tank for storing the mineral fuel oil; A second tank for storing the biodiesel fuel oil; a purifier inlet line for supplying the mineral fuel oil in the first tank to the fuel oil purifier; A biofuel supply line for supplying the biodiesel fuel oil in the second tank to the purifier inlet line; a purifier return line from the purifier inlet line to the first tank; A fuel oil switching means is provided downstream of the junction of the purifier inlet line and the biofuel supply line, for switching the mixed fuel oil in the purifier inlet line to flow through the purifier return line. Fuel oil mixing system.

3. The second tank is provided with two or more. A fuel oil mixing system according to claim 1 or claim 2.

4. The first tank is provided with two or more.

2. The fuel oil mixing system of claim 1.

5. The fuel oil purifier includes two or more of the above. A fuel oil mixing system according to claim 1 or claim 2.

6. The first tank is a storage tank.

2. The fuel oil mixing system of claim 1.

7. The first tank is a settling tank.

3. The fuel oil mixing system of claim 2.

8. A service tank is provided for storing the mixed fuel oil purified by the fuel oil purifier. A fuel oil mixing system according to claim 1 or claim 2.

9. a purifier bypass line for passing the mixed fuel oil in the purifier inlet line to the purifier return line; Downstream of the branch point between the purifier inlet line and the purifier bypass line, a fuel oil switching means for switching the mixed fuel oil in the purifier inlet line to flow through the purifier return line; 2. The fuel oil mixing system of claim 1.

10. A mixer is provided downstream of the junction.

3. The fuel oil mixing system of claim 2.

11. A mixer is provided downstream of the branch point.

10. The fuel oil mixing system of claim 9.

12. Upstream of the junction of the purifier inlet line and the biofuel supply line, A mineral fuel oil flow rate control means is provided for allowing a portion of the mineral fuel oil in the purifier inlet line to flow through the purifier return line.

3. The fuel oil mixing system of claim 2.

13. a purifier bypass line for directing at least a portion of the mixed fuel oil in the purifier inlet line to the purifier return line; The purifier bypass line is provided with a mixed oil flow rate adjustment means for adjusting the amount of the mixed fuel oil flowing to the purifier return line side.

2. The fuel oil mixing system of claim 1.

14. On the discharge side of the purifier fuel supply pump provided in the purifier inlet line, The mineral fuel oil flow rate control means is provided.

13. The fuel oil mixing system of claim 12.

15. On the discharge side of the purifier fuel supply pump provided in the purifier inlet line, The mixed oil flow rate adjusting means is provided.

14. The fuel oil mixing system of claim 13.

16. A fuel oil blending system for producing a purified fuel oil by purifying a mixed fuel oil obtained by blending a mineral fuel oil with a biodiesel fuel oil, comprising: A fuel oil purifier installed on board the ship; A first tank for storing the mineral fuel oil; A second tank for storing the biodiesel fuel oil; a purifier inlet line for supplying the mineral fuel oil in the first tank to the fuel oil purifier; A biofuel supply line for supplying the biodiesel fuel oil in the second tank to the purifier inlet line; a biodiesel return line from the biofuel supply line to the second tank; A biodiesel fuel oil switching means for switching the biodiesel fuel oil in the biofuel supply line to flow to the biodiesel return line side; A chemical supply device is provided for mixing a chemical containing at least one of an antioxidant and a pour point depressant with the biodiesel fuel oil flowing through the biodiesel return line; The drug supply device includes: A drug tank storing the drug; an agent supply line for supplying the agent in the agent tank to the biodiesel return line; A drug supply pump provided in the drug supply line; Equipped with Fuel oil mixing system.

17. In the purifier inlet line, An oil heater is provided for heating the mixed fuel oil or the mineral fuel oil.

3. The fuel oil mixing system of claim 2.

18. In the purifier inlet line, An oil heater is provided for heating the mixed fuel oil.

2. The fuel oil mixing system of claim 1.

19. A biofuel supply line for supplying the biodiesel fuel oil in the second tank to the purifier inlet line; A chemical supply device for mixing a chemical containing at least one of an antioxidant and a pour point depressant with the biodiesel fuel oil flowing through the biofuel supply line, The drug supply device includes: A drug tank storing the drug; A chemical supply line for supplying the chemical in the chemical tank to the biofuel supply line; A drug supply pump provided in the drug supply line; Equipped with A fuel oil mixing system according to claim 1 or claim 2.

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