Lubricating oil purification system and lubricating oil purification method

Abstract

To provide a lubricating oil purification system and a lubricating oil purification method that are capable of stable purification by separating lubricating oil from a stock solution containing ammonia water and the lubricating oil.SOLUTION: A lubricating oil purification system 100 can purify a stock solution DO mixed with ammonia water AW into lubricating oil. The lubricating oil purification system 100 includes: an engine 200; a lubricating oil purifier 1 configured to separate a stock solution containing the lubricating oil LO used in the engine 200 into a light liquid which is at least the purified lubricating oil LO and a heavy liquid containing ammonia; and water supply means configured to supply water W into a separation chamber SZ during operation of the lubricating oil purifier 1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a lubricating oil purification system and a lubricating oil purification method for purifying lubricating oil containing ammonia water or the like. [Background technology]

[0002] As a countermeasure against global warming, ammonia fuel, which does not emit carbon dioxide, a greenhouse gas, when burned, has attracted attention as a promising energy source for realizing a carbon-neutral society. In recent years, progress has been made in the practical application of ammonia gas turbine engines and ammonia-compatible engines that can be operated using liquid ammonia as ship fuel. Furthermore, development is also underway for the operation of ammonia-fueled ships, so-called zero-emission ships, that use liquid ammonia as fuel (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6934555 [Patent Document 2] Patent No. 6940727 Summary of the Invention [Problem to be solved by the invention]

[0004] When liquid ammonia is used in engines of ships and the like, there is a problem in that unburned ammonia gas in the engine dissolves in the water in the lubricating oil. More specifically, moisture gets mixed into the lubricating oil as condensation occurs during engine operation or after the engine is stopped. If the engine is operated without removing the moisture, the ammonia concentration in the engine increases, and the ammonia dissolves in the moisture in the lubricating oil.

[0005] Materials exposed to ammonia water or an ammonia atmosphere are prone to corrosion. In addition, in lubricant oil purifiers that separate raw liquid containing used lubricant oil into heavy liquid and light liquid (lubricant oil), if ammonia gets mixed into the raw liquid, the specific gravity of the heavy liquid decreases, the removal rate of the heavy liquid decreases, and there is a risk of problems such as the light liquid (lubricant oil) leaking from the heavy liquid side or the heavy liquid being mixed into the light liquid.

[0006] An object of the present invention is to solve the above-mentioned problems and to provide a lubricating oil purification system and a lubricating oil purification method that can stably separate lubricating oil from a stock solution containing ammonia water and lubricating oil. [Means for solving the problem]

[0007] In order to solve the above problem, the present invention provides a lubricant oil purification system capable of purifying a stock solution containing ammonia water into lubricant oil, and includes an engine, a lubricant oil purifier that separates the stock solution containing the lubricant oil used in the engine into at least a light liquid that is the purified lubricant oil and a heavy liquid that contains ammonia, and a water supply means that supplies water into a separation chamber while the lubricant oil purifier is operating.

[0008] The present invention also provides a lubricating oil purification method capable of purifying a stock solution containing ammonia water into lubricating oil, the method comprising a centrifugation step of separating the stock solution containing the lubricating oil used in an engine into a light liquid which is at least the lubricating oil purified by a lubricating oil purifier and a heavy liquid containing ammonia, and a water supply step of supplying water into a separation chamber while the lubricating oil purifier is operating. [Effects of the Invention]

[0009] The lubricating oil purification system and lubricating oil purification method of the present invention can stably separate lubricating oil from a stock solution containing ammonia water and lubricating oil. [Brief explanation of the drawings]

[0010] [Figure 1]1 is a block diagram illustrating a lubricant cleaning system and a lubricant cleaning method according to an embodiment of the present invention. [Figure 2] FIG. 2 is a central vertical cross-sectional view showing the lubricating oil purifier. [Figure 3] FIG. 2 is a central longitudinal cross-sectional view of a rotor of the lubricating oil purifier. [Figure 4] FIG. 2 is a schematic diagram showing the state inside a rotor when ordinary lubricating oil is centrifuged in a lubricating oil purifier. [Figure 5] FIG. 1 is a schematic diagram showing the state inside a rotor when general lubricating oil mixed with ammonia is centrifuged in a lubricating oil purifier. [Figure 6] FIG. 1 is a diagram showing a lubricating oil purification method according to an embodiment of the present invention, and is a schematic diagram showing the state inside the rotor when seal water and replacement water are added to lubricating oil contaminated with ammonia and centrifuged in a lubricating oil purifier. [Figure 7] FIG. 10 is a block diagram showing a modified example of the lubricant oil cleaning system and lubricant oil cleaning method according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] A lubricant oil cleaning system 100 and a lubricant oil cleaning method according to an embodiment of the present invention will be described in detail with reference to FIGS.

[0012] <Lubricant Oil Purification System> The lubricating oil purification system 100 shown in Figure 1 is a purifier for purifying waste liquids SW such as lubricating oil LO, fuel oil, and bilge water used in engines 200 installed on ships or in limited installation spaces on land (for example, remote island power plants or existing power plants) to make them reusable. Hereinafter, as an example of the lubricant oil purification system 100 according to the present invention, a case will be described in which the lubricant oil LO used in an engine 200 that burns liquid ammonia is used as waste liquid SW. In an engine 200 that uses liquid ammonia as fuel, the lubricating oil LO inside the engine 200 may be contaminated with sludge SG and aqueous ammonia AW.

[0013] The lubricating oil purification system 100 includes a lubricating oil purifier 1. The lubricating oil purifier 1 is a three-phase separation type separator plate centrifuge that separates a raw lubricating oil DO (lubricating oil LO mixed with ammonia water AW) into a light liquid (purified lubricating oil LO), a heavy liquid (ammonia water AW containing ammonia), and sludge SG (solids). More specifically, as shown in FIG. 1 or 3, the lubricating oil purification system 100 mainly includes a lubricating oil tank 300, a lubricating oil supply pump P1, a heater 400, the lubricating oil purifier 1, a sludge tank 700, a water supply line 110 (water supply means), a heavy liquid discharge line 120 (drainage means), a pressure sensor 810, a raw lubricating oil supply line 130, a sludge discharge line 160, and a control device 900. The lubricating oil purification system 100 is installed inside a ship. The light liquid discharge line 140 may be provided with a pressure sensor 810, a moisture detection sensor 820, and an ammonia sensor 830.

[0014] ≪Institution≫ The engine 200 shown in FIG. 1 is a marine diesel engine installed on a ship, which uses liquid ammonia as fuel, which has zero emissions of carbon dioxide, a greenhouse gas, and may be a turbine engine. The engine 200 is composed of a mechanism in which the crankshaft and piston are connected only by a connecting rod. In the engine 200, side pressure, which is a lateral force, is generated on the piston, causing uneven wear in the cylinder. For this reason, the engine 200 uses lubricating oil LO to improve piston movement. The engine 200 may also be one that burns a mixture of liquid ammonia and a fossil fuel such as natural gas.

[0015] <Lubricant discharge line> 1 is a piping line for sending lubricating oil LO (undiluted liquid DO) used in the engine 200 to the lubricating oil tank 300. One end of the lubricating oil discharge line 150 is connected to the engine 200, and the other end is connected to the lubricating oil tank 300.

[0016] <Lubricating oil tank and lubricating oil> 1, the lubricating oil tank 300 is a tank for storing the stock solution DO containing the lubricating oil LO used by the engine 200. The stock solution DO supplied from the engine 200 to the lubricating oil tank 300 contains ammonia derived from the ammonia fuel. For this reason, the lubricating oil tank 300 is a tank with a lid that prevents vaporized ammonia from leaking out of the lubricating oil tank 300. Furthermore, the undiluted liquid DO contains water that has been mixed in during the engine 200. The specific gravity of the undiluted liquid DO is 0.90 to 0.96.

[0017] <Ammonia water and water> Ammonia water AW is an alkaline aqueous solution in which ammonia is dissolved in water W. Ammonia water AW has a distinctive pungent odor. Ammonia water AW may corrode the fluororubber O-rings and copper alloy heavy liquid and light liquid impellers used in the lubricating oil purifier 1. For this reason, it is preferable that these parts are made of corrosion-resistant materials.

[0018] Furthermore, the specific gravity of ammonia water AW is lighter than that of water. For example, the specific gravity of ammonia water AW is 0.9 at a concentration of approximately 28% and 0.88 at a concentration of approximately 35%. Since the specific gravity of ammonia water AW changes depending on the ammonia concentration, the position of the separation boundary surface SB in the separation chamber SZ of the lubricant oil purifier 1 moves radially. Furthermore, when treating a stock solution DO containing ammonia water AW, it is preferable to control the position of the separation boundary surface SB by intermittently or continuously supplying water W into the separation chamber SZ and adjusting the specific gravity of the ammonia water AW (heavy liquid).

[0019] <Undiluted solution supply line> 1 is a piping line for supplying the raw liquid DO (lubricating oil LO mixed with sludge SG and ammonia water AW) stored in the lubricating oil tank 300 to the lubricating oil purifier 1. The raw liquid supply line 130 is made up of a heater upstream line 131 from the lubricating oil tank 300 to the heater 400, and a heater downstream line 132 from the heater 400 to the lubricating oil purifier 1. A lubricating oil supply pump P1 is provided in the heater upstream line 131, and a three-way valve 134 is provided in the heater downstream line 132.

[0020] <Lubricating oil supply pump> The lubricating oil supply pump P1 is a pump for sending the stock solution DO in the lubricating oil tank 300 from the stock solution supply line 130 to the lubricating oil purifier 1 via the heater 400. The lubricating oil supply pump P1 is installed between the lubricating oil tank 300 and the heater 400 on the heater upstream line 131. As shown in FIG. 1 , the stock solution DO in the heater upstream line 131 is mixed with ammonia water AW.

[0021] <Heater> The heater 400 is an oil heater that heats the lubricating oil LO to be sent to the lubricating oil purifier 1. The heater 400 is provided between the lubricating oil supply pump P1 on the raw solution supply line 130 and the lubricating oil purifier 1. The heater 400 heats the lubricating oil LO, for example, to about 90°C. The heater 400 can increase the efficiency of separation of solids and / or water in the lubricating oil purifier 1 by heating the lubricating oil LO to reduce its viscosity. The raw liquid return line 133 is made up of a piping path for switching the flow of raw liquid when necessary for operating operations such as when discharging sludge from the lubricating oil purifier 1, when an alarm occurs, or when replacing water or sealing water is introduced.

[0022] <Light liquid discharge line> The light liquid discharge line 140 is a flow path for returning the lubricating oil LO (light liquid) purified by the lubricating oil purifier 1 to the lubricating oil tank 300. The light liquid discharge line 140 consists of a piping path from the discharge port of the lubricating oil purifier 1 to the lubricating oil supply port of the lubricating oil tank 300.

[0023] <Lubricant oil purifier> The lubricating oil purifier 1 is a device for separating and removing sludge SG (solids) and ammonia water AW contained in the raw liquid DO supplied from the lubricating oil tank 300 from the lubricating oil LO. The lubricating oil purifier 1 may be, for example, a separator plate-type centrifuge that separates the raw liquid DO into three phases: liquid (light liquid), liquid (heavy liquid), and solids, by the centrifugal force of a rotor 3 (see FIG. 2) rotating at high speed. The lubricating oil purifier 1 is installed on board the ship between the raw liquid supply line 130 and the light liquid discharge line 140.

[0024] Next, the lubricant oil purifier 1 comprising a disc-type centrifuge will be described in more detail with reference to FIGS. As shown in Figures 2 and 3, the lubricating oil purifier 1 is a centrifuge (centrifugal settler) in which a number of separation plates 13 made of thin, truncated cone-shaped plates are stacked at intervals in the axial direction of a guide cylinder 5 inside a rotor 3. The lubricating oil purifier 1 has a mechanism for discharging sludge SG accumulated on the inner wall of the rotor 3 to the outside by opening and closing a valve cylinder 6. As shown in Figure 3, the lubricating oil purifier 1 includes a rotor shaft 2, a rotor 3, a guide cylinder 5, a separation chamber SZ, a valve cylinder 6, a light liquid discharge section 9, and a heavy liquid discharge section 15.

[0025] <Rotation axis> As shown in FIG. 2, the rotating shaft 2 has a gear portion 2a that meshes with a speed-increasing gear 21 that is rotationally driven by an electric motor (not shown), and is rotated by the electric motor (not shown) via the speed-increasing gear 21.

[0026] <Rotating body> As shown in Figure 3, the rotor 3 is attached to the rotary shaft 2 and rotates at high speed around the rotary shaft 2. The rotor 3 has an integral shape with an upper half that is roughly frusto-conical and a lower half that is a large-diameter cylindrical portion whose diameter is larger than the large diameter of the frusto-conical portion. The rotor 3 is fixed to the rotary shaft 2.

[0027] <Liquid inlet pipe> As shown in FIG. 3, the liquid inlet pipe 4 is a pipe for supplying the undiluted liquid DO (lubricating oil LO used in the engine 200) and water W into the interior of the rotor 3. The liquid inlet pipe 4 is provided above the center of the rotor 3. A water supply line 110 and an undiluted liquid supply line 130 (see FIG. 2) are connected to the upstream side of the liquid inlet pipe 4. The water W to be supplied to the separation chamber SZ of the lubricating oil purifier 1 is introduced into the rotor 3 from the water supply line 110 via the liquid inlet pipe 4.

[0028] <Guide tube> The guide tube 5 is a member for guiding the raw liquid DO and water W introduced into the rotor 3 from the liquid inlet pipe 4 to the separation chamber SZ from the lowest part of the rotor 3. The guide tube 5 is a cylindrical body with a flared shape and is located in the center of the rotor 3.

[0029] <Separation room> The separation chamber SZ is a chamber where the raw liquid DO is separated into its components based on their specific gravities using centrifugal force. The separation chamber SZ is a circular space in cross section. A number of stacked separation plates 13 are arranged in the separation chamber SZ. The separation chamber SZ includes a separation region where the stacked separation plates 13 are arranged and a sludge accumulation region at the outermost diameter of the rotor 3. As the raw liquid DO is introduced into the separation chamber SZ and flows upward through the gaps between the separation plates 13, the sludge SG, which has the highest specific gravity, accumulates in the outer sludge accumulation region. The heavy liquid (ammonia water AW or water W), which has a lower specific gravity than the sludge SG, moves to the region between the sludge accumulation region and the separation region. The light liquid (lubricating oil LO), which has the lowest specific gravity, moves toward the center of the rotor 3. The light liquid (purified lubricating oil LO) is discharged to the outside from the light liquid discharge section 9 located at the top of the rotor 3. The ammonia water (heavy liquid) AW separated in the separation chamber SZ passes through a flow path formed between the water collecting plate TD and the inner wall of the upper part of the rotor 3, and is discharged to the outside from the heavy liquid discharge part 15.

[0030] <Valve cylinder> The valve cylinder 6 is a valve body that opens and closes the sludge discharge port 12 (the portion that is pressed against the valve packing 7). When the pilot valve V is opened to drain the water below the valve cylinder 6, the valve cylinder 6 descends, opening the sludge discharge port 12 and discharging the sludge SG.

[0031] <Light liquid discharge section> The light liquid discharge section 9 is a section for discharging the lubricating oil LO (light liquid) separated in the separation chamber SZ to the outside. A light liquid discharge line 140 is attached to the light liquid discharge section 9.

[0032] <Heavy liquid discharge part> The heavy liquid discharge part 15 is a part for discharging the ammonia water (heavy liquid) separated in the separation chamber SZ to the outside. A heavy liquid discharge line 120 is attached to the heavy liquid discharge part 15.

[0033] <Sludge discharge line> The sludge discharge line 160 (drainage means) is a discharge path for discharging the sludge SG centrifuged in the lubricant oil purifier 1 to the outside of the lubricant oil purifier 1. The upstream side of the sludge discharge line 160 is connected to the sludge discharge port 12, and the downstream side is connected to the sludge tank 700 (see FIG. 1). The sludge SG in the lubricant oil purifier 1 is released into the sludge discharge line 160, stored in the sludge tank 700, and then disposed of.

[0034] <Sludge tank> The sludge tank 700 is a tank for storing the waste liquid SW discharged from the lubricant oil purifier 1. If the waste liquid SW in the sludge tank 700 is at 40° C. or higher, a cooling device for cooling the waste liquid SW may be installed.

[0035] <Water supply line> As shown in FIG. 3, the water supply line 110 is a water supply means that supplies water W (sealing water / displacement water) into the separation chamber SZ (inside the rotor 3) while the lubricant oil purifier 1 is operating. The water supply line 110 also supplies cleaning water into the separation chamber SZ during maintenance of the lubricant oil purifier 1. The water supply line 110 is provided with a valve (not shown) that adjusts the supply of water into the separation chamber SZ (inside the rotor 3). Alternatively, the water supply line 110 adjusts the supply of water by controlling the valve SV3 using the control unit 910 and timer 920 based on the measured values of any one of a pressure sensor 810, a moisture detection sensor 820, an ammonia sensor 830, and a leak detector 840, which will be described later.

[0036] <Heavy liquid discharge line> The heavy liquid discharge line 120 (drainage means) is a flow path through which the ammonia water AW (separated water) centrifuged in the lubricating oil purifier 1 is discharged, and is connected to the heavy liquid discharge section 15 of the lubricating oil purifier 1. The ammonia water AW (heavy liquid) in the lubricating oil purifier 1 overflows from the heavy liquid discharge section 15, is released into the heavy liquid discharge line 120, is stored in the sludge tank 700, and is then discarded. A leak detector 840 may be provided in the heavy liquid discharge line 120.

[0037] <Pressure sensor> The pressure sensor 810 is a measuring instrument that measures the pressure of the light liquid discharged from the light liquid discharge part 9 of the lubricant oil purifier 1. The pressure sensor 810 is electrically connected to the control part 910.

[0038] <Moisture detection sensor> The moisture detection sensor 820 is a measuring instrument that measures the amount of moisture in the light liquid discharged from the light liquid discharge section 9 of the lubricant oil purifier 1. The moisture detection sensor 820 is electrically connected to the control section 910. The moisture detection sensor 820 may be omitted depending on the condition of the lubricant oil LO.

[0039] <Ammonia sensor> The ammonia sensor 830 is a measuring instrument that measures the ammonia concentration of the ammonia water AW discharged from the light liquid discharge unit 9 of the lubricant oil purifier 1. The ammonia sensor 830 is electrically connected to the control unit 910. The ammonia sensor 830 may be omitted depending on the condition of the lubricant oil LO.

[0040] <Leak detector> The leak detector 840 is a measuring instrument that mechanically measures the heavy liquid discharged from the heavy liquid discharge unit 15 of the lubricant oil purifier 1. The leak detector 840 is electrically connected to the control unit 910. The leak detector 840 may be omitted depending on the condition of the lubricant oil LO.

[0041] <Control device> The control device 900 shown in Fig. 3 has a function of supplying water W to the lubricant oil purifier 1 intermittently or continuously at a preset timing or at any timing, thereby maintaining the specific gravity of the ammonia water AW (heavy liquid) in the separation chamber SZ at a predetermined value or higher. The control device 900 is configured to include a control unit 910 and a timer 920. The control unit 910 is connected to the timer 920, a pressure sensor 810, a moisture detection sensor 820, an ammonia sensor 830, and a leak detector 840.

[0042] <Clean lubricating oil> The cleaned lubricating oil is the lubricating oil LO that has been purified by the lubricating oil purifier 1. The cleaned lubricating oil is stored again in the lubricating oil tank 300 from the lubricating oil purifier 1 via the light liquid discharge line 140, and then supplied to the engine or auxiliary machinery (e.g., generator, boiler, etc.) of the ship.

[0043] ≪Effect≫ Next, the operation of the lubricant oil cleaning system 100 and the lubricant oil cleaning method according to the embodiment of the present invention will be described with reference to Figs. 1 to 6, in comparison with the case where the lubricant oil LO is separated under normal conditions.

[0044] For example, as shown in Fig. 1, lubricating oil LO (undiluted DO) used in an engine 200 is stored in a lubricating oil tank 300 and then introduced into the lubricating oil purifier 1 through an undiluted liquid supply line 130. The undiluted liquid DO introduced into the lubricating oil purifier 1 flows upward between a plurality of stacked separator plates 13, as shown in Fig. 3.

[0045] FIG. 4 is a schematic diagram showing the state inside the rotor 3 when the stock solution DO not containing the aqueous ammonia AW is centrifuged in the lubricating oil purifier 1. As shown in FIG. Normally, as shown in Figure 4, components with a high specific gravity (sludge SG, water W, etc.) move to the outermost diameter side of the rotor 3 and are separated. Components with a low specific gravity (lubricating oil LO) move to the center side of the rotor 3 and are separated.

[0046] FIG. 5 is a schematic diagram showing the state inside the rotor 3 when the raw solution DO mixed with ammonia is centrifuged in the lubricant oil purifier 1.

[0047] Generally, when the raw liquid DO mixed with the ammonia water AW is supplied into the rotor 3, it is separated into the lubricating oil LO, the ammonia water AW, and the sludge SG, as shown in FIG.

[0048] Ammonia water AW has a lower specific gravity than water W that does not contain ammonia. As a result, the difference in specific gravity between the light liquid (lubricating oil LO) and the heavy liquid (ammonia water AW) becomes smaller, which may reduce the efficiency of separation between the light liquid (lubricating oil LO) and the heavy liquid (ammonia water AW). In addition, the separation boundary surface SB between the ammonia water AW and the lubricating oil LO moves outward due to being pushed by the lubricating oil LO. Therefore, if the ammonia concentration of the ammonia water AW becomes high (for example, if the ammonia concentration exceeds 6 wt%), there is a risk that the light liquid will leak (the light liquid will flow into the heavy liquid discharge line 120) when three-phase separation is performed (when the purifier is operated). Furthermore, when the concentration of the ammonia water AW is high, the difference in specific gravity between the light liquid and the heavy liquid becomes small, and therefore the water W that accumulates in the rotor 3 cannot position the separation boundary surface SB in an ideal position.

[0049] FIG. 6 is a diagram showing a lubricating oil purification method according to an embodiment of the present invention, and is a schematic diagram showing the state inside the rotor 3 when replacement water is added to lubricating oil LO contaminated with ammonia and the lubricating oil LO is centrifuged in the lubricating oil purifier 1.

[0050] In this embodiment, in the process of centrifuging raw water DO mixed with ammonia water AW (centrifugal separation process), water is supplied into the separation chamber SZ (water supply process), so that the specific gravity of the ammonia water AW in the separation chamber SZ can be restored to a predetermined value or higher. In this way, by introducing water W into the separation chamber SZ, the specific gravity of the ammonia water AW can be maintained at a certain value or higher, so that loss of lubricating oil LO (light liquid flowing out to the heavy liquid discharge part 15) can be minimized, and stable normal operation can be performed.

[0051] The water supply process may be performed intermittently or continuously by the timer 920 and the control device 900 shown in Fig. 3. Alternatively, the water supply process may be performed when the measurement value of at least one of the pressure sensor 810, the moisture detection sensor 820, the ammonia sensor 830, and the leak detector 840 reaches a threshold value. In this way, the specific gravity of the ammonia water AW can be maintained at or above a predetermined value (i.e., the difference in specific gravity between the ammonia water AW and the lubricating oil LO in the separation chamber SZ can be maintained at or above a predetermined value).

[0052] In the discharge process, the ammonia water AW and the sludge SG may be discharged at regular intervals or when a measurement value of at least one of the pressure sensor 810, the moisture detection sensor 820, the ammonia sensor 830, and the leak detector 840 reaches a threshold value by the timer 920 and the control device 900. Note that the discharge process and the water supply process are not performed simultaneously, but only one of them is performed.

[0053] As described above, according to this embodiment, raw water DO containing ammonia can be separated into ammonia water AW, lubricating oil LO, and sludge SG, and purified lubricating oil LO can be obtained.

[0054] A first embodiment of the present invention is a lubricant oil purification system 100 that can purify a stock solution DO contaminated with ammonia water AW into a lubricant oil LO, as shown in, for example, FIG. 1 or FIG. 3, and includes an engine 200, a lubricant oil purifier 1 that separates the stock solution DO containing the lubricant oil LO used in the engine 200 into at least a light liquid that is the purified lubricant oil LO and a heavy liquid that contains ammonia, and a water supply means (water supply line 110) that supplies water W into a separation chamber SZ while the lubricant oil purifier 1 is operating.

[0055] With this configuration, the lubricant oil purifier 1 can separate the lubricant oil LO, the sludge SG, and the ammonia water AW from the raw liquid DO. In addition, the water supply means (water supply line 110) that supplies water W to the separation chamber SZ of the lubricating oil purifier 1 while it is in operation makes it possible to make the difference in specific gravity between the light liquid (lubricating oil LO) and the heavy liquid (ammonia water AW) in the separation chamber SZ to a level suitable for sedimentation separation, thereby enabling stable, normal operation. Furthermore, since the separation boundary surface SB between the ammonia water AW and the lubricating oil LO in the separation chamber SZ can be prevented from being formed outside the water collection plate TD, the lubricating oil LO can be stably separated from the raw liquid DO containing the ammonia water AW, etc., which is discharged to the lubricating oil purifier 1.

[0056] The lubricant cleaning system 100 also includes a drainage means (heavy liquid discharge line 120) for discharging the heavy liquid to the outside of the separation chamber SZ.

[0057] According to this configuration, the lubricating oil purification system 100 is equipped with a heavy liquid discharge line 120, so that when a predetermined amount or more of heavy liquid accumulates inside the lubricating oil purifier 1, the heavy liquid can overflow and be discharged outside the lubricating oil purifier 1.

[0058] As shown in FIG. 3, the lubricant oil purification system 100 is also provided with a pressure sensor 810 that detects the pressure of the light liquid discharged from the light liquid discharge section 9 of the lubricant oil purifier 1.

[0059] According to this configuration, by detecting the pressure of the light liquid discharged from the light liquid discharge section 9 using the pressure sensor 810, an appropriate amount of water W can be supplied to the lubricating oil purifier 1 according to the pressure of the light liquid in the lubricating oil purifier 1.

[0060] As shown in FIG. 3, the lubricant oil purification system 100 is also provided with a moisture detection sensor 820 that detects the amount of moisture in the light liquid discharged from the light liquid discharge section 9 of the lubricant oil purifier 1.

[0061] According to this configuration, water W can be supplied to the lubricant oil purifier 1 in accordance with the amount of water in the light liquid discharged from the light liquid discharge portion 9.

[0062] As shown in FIG. 3, the lubricant oil purification system 100 is also provided with an ammonia sensor 830 that detects the ammonia concentration of the light liquid (lubricant oil LO) discharged from the light liquid discharge section 9 of the lubricant oil purifier 1.

[0063] According to this configuration, the water W can be supplied to the lubricant oil purifier 1 in accordance with the ammonia concentration of the ammonia water AW.

[0064] As shown in FIG. 3, the lubricant oil purification system 100 also includes a leak detector 840 that detects leakage of light liquid from the heavy liquid discharged from the heavy liquid discharge section 15 of the lubricant oil purifier 1.

[0065] According to this configuration, the leak detector 840 detects leakage of the light liquid, and water is supplied according to the amount of leaked light liquid, thereby allowing the lubricant oil purifier 1 to operate in a stable state.

[0066] As shown in FIG. 1, the lubricant oil purification system 100 includes a lubricant oil tank 300 for storing the raw liquid DO, a separator inlet line (raw liquid supply line 130) for supplying the raw liquid DO in the lubricant oil tank 300 to the lubricant oil purifier 1, and a light liquid discharge line 140 for returning the light liquid (lubricant oil LO) flowing out of the lubricant oil purifier 1 to the lubricant oil tank 300. The separator inlet line (raw liquid supply line 130) is provided with a lubricant oil supply pump P1 for sending the raw liquid DO stored in the lubricant oil tank 300 to the lubricant oil purifier 1, a heater 400 for heating the lubricant oil LO to be sent to the lubricant oil purifier 1, and a three-way valve 134.

[0067] According to this configuration, the heater 400 can heat the undiluted liquid DO (lubricant oil LO) to reduce its viscosity, so that the efficiency of separating solids and water in the lubricant oil purifier 1 can be increased.

[0068] The lubricant oil purifier 1 shown in FIGS. 1 to 3 is a disc-type centrifugal separator.

[0069] According to this configuration, the lubricating oil purifier 1 is a separation plate type centrifugal separator, and therefore can exhibit high separation performance despite its small size, and can purify the lubricating oil in a relatively short time.

[0070] As shown in FIG. 1 or 3, the lubricating oil purification method is capable of purifying a stock solution DO contaminated with ammonia water AW into a lubricating oil LO, and includes a centrifugal separation process in which the stock solution DO, in which ammonia water AW has been mixed into the lubricating oil LO used in the engine 200, is separated by the lubricating oil purifier 1 into a light liquid, which is at least the purified lubricating oil LO, and a heavy liquid containing ammonia, and a water supply process in which water W is supplied into the separation chamber SZ while the lubricating oil purifier 1 is operating, thereby purifying the stock solution DO contaminated with ammonia water AW and enabling stable normal operation.

[0071] According to this lubricant oil purification method, the stock solution DO containing ammonia water AW is separated into ammonia water AW, lubricant oil LO, and sludge SG. Water is supplied before the difference in specific gravity between the light liquid and the heavy liquid becomes small, or when the light liquid flows into the heavy liquid discharge line 120. This allows the specific gravity of the ammonia water AW in the separation chamber SZ to be adjusted to a predetermined value or higher. This allows the difference in specific gravity between the light liquid (lubricant oil LO) and the heavy liquid (ammonia water AW) in the separation chamber SZ to be maintained at a level suitable for sedimentation and separation. Furthermore, the separation interface SB between the ammonia water AW and the lubricant oil LO can be positioned as desired, thereby minimizing loss of the lubricant oil LO and producing a lubricant oil LO with fewer impurities. In other words, the above-described lubricant oil purification method provides a lubricant oil purification system that can stably purify a stock solution DO containing ammonia water AW and other contaminants into lubricant oil LO.

[0072] [Variations] The present invention is not limited to the above-described embodiment, and various modifications and changes are possible within the scope of the technical concept thereof, and the present invention naturally extends to such modified and changed inventions. Note that the same reference numerals are used to designate components that have already been described, and their description will be omitted. FIG. 7 is a block diagram showing a modified example of the lubricant oil cleaning system and lubricant oil cleaning method according to the embodiment of the present invention.

[0073] As shown in FIG. 7, the lubricant oil purification system 100 may include at least a waste liquid tank 500 for storing waste liquid SW, and a neutralization tank 600 for storing a neutralizing agent CA for neutralizing the waste liquid SW (separated water) stored in the waste liquid tank 500.

[0074] According to this configuration, by supplying the neutralizing agent CA of the neutralization tank 600 to the waste liquid SW (separated water) of the waste liquid tank 500, the waste liquid SW can be made harmless.

[0075] <Neutralization tank> The neutralization tank 600 is a tank for storing a neutralizing agent CA that neutralizes the mixture of sludge SG and ammonia water AW (hereinafter referred to as waste liquid SW) stored in the waste liquid tank 500. The neutralization tank 600 is provided with a neutralizing agent supply line 170 that supplies the neutralizing agent CA in the neutralization tank 600 to the waste liquid tank 500.

[0076] <Neutralizer> The neutralizing agent CA is an acidic agent for neutralizing the waste liquid SW in the waste liquid tank 500, and is made of, for example, citric acid. The neutralizing agent CA is added to the wastewater SW in the waste liquid tank 500 and is made of a solid or liquid.

[0077] <Waste liquid tank> 7 is a tank for storing waste liquid SW containing sludge SG separated by the lubricant oil purifier 1. The waste liquid tank 500 is disposed downstream of the sludge discharge line 160 that supplies the sludge SG separated by the lubricant oil purifier 1 to the waste liquid tank 500. The waste liquid SW containing sludge SG is deposited on the outermost diameter side of the rotor 3 by the centrifugal force of the lubricating oil purifier 1, and is discharged from the sludge discharge port 12 through the sludge discharge line 160 to the waste liquid tank 500, and then stored in the sludge tank 700 through the waste liquid discharge line 180. In this embodiment, the ammonia water AW (heavy liquid) separated in the lubricant oil purifier 1 is also stored in the waste liquid tank 500. As shown in Figure 3, the heavy liquid discharge part 15, which is the discharge port for the ammonia water AW, is connected to the sludge discharge line 160. The waste liquid tank 500 may be provided with an air vent member for removing vaporized ammonia and a deodorizing device for eliminating the odor of ammonia.

[0078] [Other variations] In the above embodiment, as shown in FIG. 1, the case where only one lubricant oil purifier 1 is installed has been described, but a configuration in which a plurality of lubricant oil purifiers 1 are arranged in parallel may also be used.

[0079] In the above embodiment, an example was shown in which the water supply line 110 (water supply means) was connected to the liquid inlet pipe 4, but the water supply line 110 (water supply means) may also be connected to the lubricating oil tank 300, or the water supply line 110 (water supply means) may also be connected to the concentrate supply line 130.

[0080] In the above embodiment, the lubricant oil purifier 1 is a three-phase separation type separation plate centrifuge, but a two-phase separation type separation plate centrifuge may also be used. In this case, the lubricant oil purifier 1 separates the raw liquid DO, which is the lubricant oil LO mixed with ammonia water AW, into a sludge SG containing a heavy liquid containing ammonia water AW and a light liquid, which is the purified lubricant oil LO. When a two-phase separation type separation plate centrifuge is used as the lubricant oil purifier 1, it is preferable to discharge the lubricant oil when the measurement value of any of the pressure sensor 810, moisture detection sensor 820, ammonia sensor 830, and leak detector 840 of the lubricant oil purifier 1 reaches a threshold value. The moisture detection sensor 820, the ammonia sensor 830, and the leak detector 840 may be omitted depending on the condition of the lubricating oil LO. [Explanation of symbols]

[0081] 1 Lubricating Oil Purifier 9 Light liquid discharge section 15 Heavy liquid discharge part 100 Lubricant Oil Purification System 110 Water supply line (water supply means) 120 Heavy liquid discharge line (drainage means) 130 Raw liquid supply line (separator inlet line) 133 Concentrate return line 134 Three-way valve 140 Light liquid discharge line 200 institutions 300 Lubricating Oil Tank 400 heater 500 Waste tank 600 Neutralization Tank 700 Sludge Tank 810 Pressure Sensor 820 Moisture detection sensor 830 Ammonia Sensor 840 Leak Detector 900 Control device AW Ammonia water (heavy liquid) CA Neutralizer DO stock solution LO Lubricating oil (light liquid) P1 Lubricating oil supply pump SG Sludge SZ separation chamber SW waste liquid (separated water) W water

Claims

1. A lubricating oil purification system that can purify a raw solution containing ammonia water into lubricating oil, Institutions and a lubricating oil purifier that separates the raw liquid containing the lubricating oil used in the engine into a light liquid that is at least the purified lubricating oil and a heavy liquid that contains ammonia; and a water supply means for supplying water into the separation chamber during operation of the lubricating oil purifier. Lubricant oil purification system.

2. A drainage means is provided for discharging the heavy liquid to the outside of the separation chamber. The lubricant cleaning system of claim 1 .

3. A pressure sensor is provided to detect the pressure of the light liquid discharged from the light liquid discharge portion of the lubricating oil purifier. The lubricant cleaning system of claim 1 .

4. A moisture detection sensor is provided to detect the amount of moisture in the light liquid discharged from the light liquid discharge portion of the lubricating oil purifier. The lubricant cleaning system of claim 1 .

5. An ammonia sensor is provided to detect the ammonia concentration of the light liquid discharged from the light liquid discharge portion of the lubricating oil purifier. The lubricant cleaning system of claim 1 .

6. A leak detector is provided to detect leakage of light liquid from the heavy liquid discharged from the heavy liquid discharge portion of the lubricating oil purifier. The lubricant cleaning system of claim 1 .

7. a lubricating oil tank for storing the stock solution; a separator inlet line for supplying the raw liquid in the lubricant oil tank to the lubricant oil purifier; a light liquid discharge line for returning the light liquid flowing out of the lubricant oil purifier to the lubricant oil tank; The separator inlet line includes: a lubricant oil supply pump for sending the raw liquid stored in the lubricant oil tank to the lubricant oil purifier; a heater for heating the lubricating oil to be sent to the lubricating oil purifier; The lubricant cleaning system of claim 1 .

8. The lubricating oil purifier is a separator plate type centrifuge, The lubricant cleaning system of claim 1 .

9. A lubricating oil purification method that can purify a raw solution containing ammonia water into lubricating oil, a centrifugal separation step of separating the raw liquid containing the lubricating oil used in the engine into a light liquid which is the lubricating oil that has been at least purified by a lubricating oil purifier and a heavy liquid containing ammonia; A water supplying step of supplying water into the separation chamber during operation of the lubricating oil purifier; Lubricating oil cleaning method.

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